EPA420-R-98-017
Draft Regulatory Impact Analysis:
Control of Emissions from
Compression-Ignition Marine Engines
EPA
U.S. Environmental Protection Agency
Office of Air and Radiation
Office of Mobile Sources
Engine Programs and Compliance Division
November 1998
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Table of Contents
CHAPTER 1: INTRODUCTION 1
CHAPTER 2: INDUSTRY CHARACTERIZATION 5
I. Introduction 5
II. Variety of Marine Diesel Engines 5
A. Broad Engine Categories 5
B. Category 1 Engine Subgroups 6
C. Auxiliary and Propulsion Engines 8
D. Recreational and Commercial 9
III. Marine Engine Production 9
IV. Description of Engine Manufacturers 10
A. Sources of Information 10
B. Category 1 Engines 11
C. Category 2 Engine Manufacturers 17
D. Category 3 Engine Manufacturers 19
V. Recreational Boat Builders 19
A. Introduction 19
B. Identification and Location of Builders 20
C. Sales and Employment Figures 20
D. Production Practices 21
E. Gasoline Engine vs. Diesel Engine Installation in Recreational Vessels in
theU.S 21
VI. Commercial Vessel Builders 22
A. Introduction 22
B. Vessel Types 22
C. Shipbuilders 23
D. Boat Builders 24
CHAPTER 3: TECHNOLOGICAL FEASIBILITY 29
I. Introduction 29
II. Marine Diesel Engine Design Ratings 29
A. High Performance Ratings: Recreational Marine Engines 29
B. Other Ratings: Commercial Marine Engines 30
III. The Marinization Process 31
IV. Background on Diesel Emission Formation 32
V. General Description of Emission Control Strategies 33
A. Combustion Optimization 33
B. Advanced Fuel Injection Controls 35
C. Improving Charge Air Characteristics 36
D. Electronic Control 38
E. Exhaust Gas Recirculation 38
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F. Exhaust Aftertreatment Devices 39
G. Water Emulsification 41
VI. Emission Measurement 41
A. Certification Duty Cycles 41
B. Relative Stringency of Duty Cycles 44
C. Emission Control of Typical In-Use Operation 46
D. Emissions Sampling 53
VII. Baseline Technology Mix 54
A. Category 1 Marine Diesel Engines 54
B. Category 2 Marine Diesel Engines 55
C. Category 3 Marine Diesel Engines 56
VIII. Low Emission Category 1 Marine Engines 58
IX. Anticipated Technology Mix 61
A. Category 1 Marine Diesel Engines 61
B. Category 2 Marine Diesel Engines 62
C. Category 3 Marine Diesel Engines 62
X. Test Fuel Specifications 63
A. Category 1 and 2 Marine Diesel Engines 63
B. Category 3 Marine Diesel Engines 64
XI. Impact on Noise, Energy, and Safety 66
CHAPTER 4: ECONOMIC IMPACT 73
I. Methodology 73
II. Overview of Technologies 74
III. Technology Costs 76
A. Electronic Controls 77
B. Fuel Injection Improvements 78
C. Engine Modifications 79
D. Turbocharging 80
E. Aftercooling 81
F. Exhaust Gas Recirculation 83
G. Rebuild Costs 84
H. Certification and Compliance 86
I. Total Engine Costs 87
J. Sensitivity 94
IV. Aggregate costs 94
CHAPTER 5: ENVIRONMENTAL IMPACTS 97
I. Health and Welfare Concerns 97
A. Ozone 97
B. Particulate Matter 98
C. Carbon Monoxide 100
D. Smoke 100
II. Emission Reductions 100
A. Category 1 101
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B. Category 2 109
C. Category 3 112
D. Nationwide Totals 114
E. Other Impacts of NOx Emission Reductions 118
F. Air Toxics 119
CHAPTER 6: COST-EFFECTIVENESS 121
I. Engine Lifetime Cost-Effectiveness of the Proposed Standards 122
A. HC+NOx 122
B. PM 126
C. Comparison with Cost-Effectiveness of Other Control Programs 128
II. 30-Year Cost-Effectiveness of the Proposed Standards 130
A. HC+NOx 130
B. PM 130
in
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Chapter 1: Introduction
CHAPTER 1: INTRODUCTION
EPA is proposing new standards for emissions of oxides of nitrogen (NOx), hydrocarbons (HC),
carbon monoxide (CO), and particulate matter (PM) from diesel-cycle engines with a gross power
output at or above 37 kilowatts used in marine engines.1 This Draft Regulatory Impact Analysis
(Draft RIA) provides technical, economic, and environmental analyses of the proposed emission
standards for the affected engines. The anticipated emission reductions would translate into
significant, long-term improvements in air quality in many areas of the U.S. In 2020, the proposed
standards are proj ected to result in reductions of 9 percent HC, 28 percent NOx, 12 percent PM, and
3 percent CO from marine diesel engines used in the U. S. The NOx reduction would be in addition
to a 7 percent reduction in 2020 that will be achieved by adopting international standards for U.S.
flagged vessels. Overall, the proposed requirements would provide much needed assistance to states
and regions facing ozone and particulate air quality problems that are causing a range of adverse
health effects, especially in terms of respiratory impairment and related illnesses.
Chapter 2 contains an overview of the manufacturers, including a brief description of the
engines or vessels, that would be affected by the proposed rule. Chapter 3 provides a description of
the range of technologies being considered for improving emission control from these engines,
including detailed projections of a possible set of compliance technologies. Chapter 4 applies cost
estimates to the projected technologies for several different power categories and describes the
potential impacts on small businesses. These costs are summarized in Table 1-3. Chapter 5 provides
an overview of the health and welfare issues involved and presents the calculated reduction in
emission levels resulting from the proposed standards. Chapter 6 compares the costs and the
emission reductions to estimate the cost-effectiveness of the rulemaking.
EPA has created these categories to define the three distinctive types of marine diesel engines.
Category 1 includes engines greater than 37 kW but with a per cylinder displacement of less than or
equal to 5 liters/cylinder. Category 2 includes engines with 5 to 20 liters/cylinder, and Category 3
includes the remaining, very large, engines.
Beginning in 2000, marine diesel engines greater than or equal than 130 kW will be subject to
an international NOx emissions standard developed by International Maritime Organization (EVIO).
This standard is considered to be the baseline case (or "Tier 1") for determining the benefits of the
proposed EPA standards. The EVIO NOx standard is presented in Table 1-1.
1 Diesel-cycle engines, referred to simply as "diesel engines" in this analysis, may also be
referred to as compression-ignition (or CI) engines. These engines typically operate on diesel
fuel, but other fuels may be also be used. This contrasts with Otto-cycle engines (also called
spark-ignition or SI engines), which typically operate on gasoline.
1
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Regulatory Impact Analysis
Table 1-1
IMP Marine Diesel Engine NOx Standard
Effective Date
2000
rated speed (n)
n >2000 rpm
130 37 kW
0.5 < disp. < 0.9
0.9 < disp. < 1.2
1.2 < disp. < 1.5
1.5 < disp. < 2.0
2.0 < disp. < 2.5
2.5 < disp. < 5.0
5.0 < disp. < 20
Tier
2
O
2
O
2
O
2
O
2
3
2
3
2
3
Effective
Date
2004
2008
2004
2008
2004
2008
2004
2008
2004
2008
2006
2010
2006
2010
HC+NOx
g/kW-hr
7.2
4.0
7.2
4.0
7.2
4.0
7.2
4.0
7.2
4.0
7.2
5.0
7.2
5.0
CO
g/kW-hr
5.0
5.0
5.0
5.0
3.5
3.5
3.5
3.5
3.5
3.5
3.5
3.5
2.0
2.0
PM
g/kW-hr
0.40
subject to review
0.30
subject to review
0.20
subject to review
0.20
subject to review
0.20
subject to review
0.20
subject to review
0.27
subject to review
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Chapter 1: Introduction
This document presents an analysis of the projected regulatory impacts of the proposed rule.
Included in these impacts are engine and operating costs, emissions benefits, and the associated cost-
effectiveness of the rule. Table 1-3 presents these impacts on a per-engine basis for five different
engine sizes. The listed engine costs reflect the full anticipated price increment resulting from the
proposed emission standards. These costs are adjusted in the cost-effectiveness calculation to take
into account the value of non-emission benefits (such as improved performance). The operating
costs presented here are the net present value of the lifetime operating costs using a seven percent
rate. Because the focus of this proposed rule is on ground-level ozone, all of the costs are applied
to HC+NOx benefits. The benefits are discounted at a rate of seven percent to the year that the
engine is introduced into commerce. All of the costs for the proposed Tier 2 standards are with
respect to baseline. The benefits are incremental compared to the EVIO requirements. Both the costs
and benefits presented here for the proposed Tier 3 standards are incremental to Tier 2.
Table 1-3
Projected Discounted Incremental Costs and Benefits by Power Rating (kW)
Power
Rating
37-225
225-560
560-1000
1000-2000
2000-5000
Tier
Tier 2
Tier 3 (years 1-5)
Tier 3 (years 6 +)
Tier 2
Tier 3 (years 1-5)
Tier 3 (years 6 +)
Tier 2
Tier 3 (years 1-5)
Tier 3 (year 6 +)
Tier 2
Tier 3 (years 1-5)
Tier 3 (year 6 +)
Tier 2
Tier 3 (years 1-5)
Tier 3 (year 6 +)
Engine
Cost*
$2,577
$5,303
$1,112
$4,249
$6,210
$1,829
$25,319
$25,507
$6,601
$22,725
$26,537
$10,659
$54,103
$44,583
$3,169
Operating
Costs
$737
$829
$1,128
$1,119
$207
$2,647
$635
$4,519
$12,430
$2,874
HC+NOx
Benefits
4.3
4.2
26
30
80
77
267
136
829
290
Cost-
Effectiveness
$449
$1,155
$279
$116
$196
$58
$283
$308
$62
$76
$178
$62
$58
$127
$16
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Regulatory Impact Analysis
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Chapter 2: Industry Characterization
CHAPTER 2: INDUSTRY CHARACTERIZATION
I. Introduction
To help assess the potential impact of the proposed emission control program, it is important
to understand the nature of the affected industries. This chapter describes the marine diesel and
vessel industries along several dimensions, including the variety of engines produced for this market,
the ways in which they are produced, the types of companies that produce these engines, and the
types of companies that manufacture the vessels on which they are installed. The picture that
emerges is one of a complex industry, both in terms of products made and the markets in which they
are sold.
II. Variety of Marine Diesel Engines
A. Broad Engine Categories
The proposed emission control program is intended to cover all marine diesel engines at or
above 37 kW introduced into commerce in the United States. Thus, the rule encompasses a wide
range of engines, from an auxiliary engine used on a small fishing vessel to a propulsion engine
installed on an ocean-going vessel. Because of the differences among these engines, it is not
possible to design one set of emission limits that would apply to all of them. Therefore, as discussed
in the Notice of Proposed Rulemaking (NPRM), EPA is proposing to divide marine diesel engines
into three subcategories. These engine groups are intended to reflect the similarities between the
marine diesel engines in each group and their land-based counterparts.
Category 1 engines are proposed to be engines with rated power at or above 37 kW but with a
specific displacement of less than 5 liters per cylinder. These engines are similar to land-based
nonroad diesel engines that are used in applications ranging from skid-steer loaders to large earth
moving machines. Category 2 engines are proposed to be engines with a specific displacement at
or above 5 liters to 20 liters per cylinder. These are similar to locomotive engines. Category 1 and
Category 2 marine diesel engines are often derived from or use the same technologies as their land-
based counterparts. Consequently, EPA believes that most of the technology being developed to
enable the land-based counterparts to achieve recently finalized emission control programs can be
applied to these marine diesel engines.1'2 Already, limited experience with the application of land-
based nonroad Tier 2 control technologies to marine engines, as part of low-emission demonstration
programs, shows that Category 1 marine diesel engines can achieve emission levels comparable to
the proposed Tier 2 standards for nonroad diesel engines. It is anticipated that this will also be the
case when locomotive Tier 2 technologies are applied to Category 2 engines. These technologies
and their application to marine diesel engines are discussed in greater detail in Chapter 3.
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Regulatory Impact Analysis
Category 3 engines are very large engines, at or above 20 liters per cylinder. These are the
largest mobile source engines addressed by EPA. They are similar in size to land-based power plant
generators, and are used primarily for propulsion in ocean-going vessels. Because they are currently
designed for maximum fuel efficiency and performance without consideration of the impacts on
NOx emissions, these engines can have very high NOx emissions. In general, Category 3 marine
engines are maintained by crews whose job is to optimize adjustable parameters on the engines to
reflect ambient conditions. These engines are already using advanced controls of charge air
temperature and pressure which are considered to be emission control strategies for smaller engines.
However, NOx reductions can still be achieved through fuel injection control strategies such as rate
shaping. Therefore, the NOx standards developed by the International Maritime Organization are
appropriate for Category 3 engines.
Table 2-1
Engine Category Definitions
Category
1
2
3
Displacement per Cylinder
disp. < 5 liters
(and power <37 kW)
5 < disp. < 20 liters
disp. > 20 liters
Basic Engine Type
Nonroad
Locomotive
Unique, "Cathedral"
B. Category 1 Engine Subgroups
EPA is further proposing to divide Category 1 engines into several subgroups. These subgroups
are similar to the land-based nonroad diesel engine subgroups, with one significant change: EPA
is proposing to base the marine subgroups on engine displacement rather than engine power. EPA
believes this is a more appropriate scheme for two reasons. First, manufacturers sometimes offer
different engine models that are the same except for the number of cylinders. These engines may
fall into different power groupings by virtue of the added power from adding cylinders. Second,
marine engines are often available in a wider range of power than their land-based counterparts.
While it may be possible to define wider power bands for marine diesel engine subgroups, it may
not be possible to do so without creating phase-in disadvantages for particular companies, especially
in comparison to their land-based phase-in schedule. A displacement scheme should minimize these
inequities. Consequently, EPA is proposing a displacement approach to defining engine groups, as
described in Table 2-2.
In selecting the displacement values corresponding with the nonroad power ranges, EPA
examined the engine displacement and power characteristics of a wide range of existing engines, as
shown in Table 2-2. The listed displacement values were selected to provide the greatest degree of
consistency with the established land-based nonroad engine power groups. The wide range in power
ratings for engines with a given per-cylinder displacement, however, led to a high degree of overlap
in the attempted correlation between displacement and power rating. As a result, some nonroad
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Chapter 2: Industry Characterization
engine models that were spread across different power groupings are brought together under a single
displacement grouping. This has the potential to move an engine model into a group with somewhat
more or less stringent requirements, but in almost all cases there was sufficient overlap to avoid
moving a family of engines into an entirely new grouping. The observed overlap highlights the
benefit of relying on displacement for a simplified approach. This should give manufacturers
opportunity to more sensibly plan an R&D effort to a family of engines that must meet a single set
of requirements with a common implementation date.
The most important aspect of defining sub-groups relates to which engines are treated like
nonroad diesel engines rated above 560 kW. Emission limits and implementation dates for smaller
marine engines are relatively uniform; however, the biggest group of Category 1 engines are subj ect
to less stringent emission limits (for Tier 3) and have more lead time. Investigation of engine models
led to three key observations. First, of the engines lines with per-cylinder displacement between 2.5
and 5.0 liter, all had configurations with available power ratings above 560 kW. Several of these
were much greater than 560 kW. Second, except for one instance, all engines with displacements
less than 2.5 liter had configurations with available power ratings below 560 kW; this means that
the manufacturers of these engines would have to meet the more aggressive requirements for some
of those engines. The only exception is the DDC 149 series engines, which is being replaced with
a new engine model. Third, the common practice of bolting two marine engines together could in
many cases move the combined engine artificially into the less stringent regime. For example, with
respect to emissions and performance, two six-cylinder 300 kW engines bolted together would
operate the same as each individual engine. Yet, by doubling the power at the crankshaft, the engine
would be subject to less challenging requirements.
The net effect of changing to a displacement-based grouping is hard to quantify. Somewhat
greater emission reductions would likely result for the reasons described above, though it is difficult
to identify the relative sales volumes of engines that would fall above and below the threshold under
both scenarios. The effect on costs is expected to be small. As described above, no engines would
be subject to the more stringent standards that would not have a subset of the engine line subject to
those same standards under a power-based grouping arrangement. As a result, there should be no
increase in R&D. Variable costs would be incurred for a greater number of engines, but the costs
analysis in Chapter 4 makes clear that fixed costs dominate the overall cost impact of emission
requirements.
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Regulatory Impact Analysis
Table 2-2
Nonroad Power Categories and Selected Engine Models
Corresponding to Per-Cylinder Displacement Ranges
Engine Power
37560
(hp>750)
Displacement,
liters/cylinder
displ.<0.9
0.9
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Chapter 2: Industry Characterization
D. Recreational and Commercial
Marine diesel engines can also be distinguished according to whether they are used on
recreational or commercial vessels. This distinction is important because these engines are not
identical.
Commercial vessels are typically displacement vessels, which means the engine pushes the
vessel through the water. Optimal operation is more a function of hull characteristics, which are
designed to reduce drag, than engine size. The power ratings of the engines used in these vessels are
analogous to those used in land-based applications. Commercial vessels are typically heavily used,
and their engines are designed to operate for as many as 2,000 to 5,000 hours a year at the higher
engine loads needed to push the vessel and its cargo through the water. Commercial vessels are
generally not serially produced. Instead, they are designed for a specific user, and many
characteristics, including the choice of engines, are set by the purchaser.
The operation and design characteristics of recreational vessels are very different from
commercial vessels. Recreational vessels are designed for speed and therefore typically operate in
a planing mode. To enable the vessel to be pushed onto the surface of the water where it will
subsequently operate, recreational vessels are constructed of lighter materials and use engines with
high power density (power/weight). The tradeoff on the engine side is less durability, and these
engines are typically warranted for fewer hours of operation. Fortunately, this limitation typically
corresponds with actual recreational vessel use. With regard to design, these vessels are more likely
to be serially produced. They are generally made out of light-weight fiberglass. This material,
however, minimizes the ability to incorporate purchaser preferences, not only because many features
are designed into the fiberglass molds, but also because these vessels are very sensitive to any
changes in their vertical or horizontal centers of gravity. Consequently, optional features are
generally confined to details in the living quarters, and engine choice is very limited or is not offered
at all.
III. Marine Engine Production
Reflecting differences in their size and base engines, different marine diesel engines are
produced in different ways. Not surprisingly, the largest of these engines, Category 3 engines, have
perhaps the most complicated production process. These engines are generally uniquely built and
designed for a particular vessel used in a particular application. Although their design may draw on
technologies used in stationary source applications, Category 3 engines are not typically derived from
a pre-developed land-based application. In addition, because they are so large, the engine often
becomes part of the structure of the vessel.
Category 1 and 2 marine diesel engines, on the other hand, are often derived from land-based
engines. Because of this, their production is often referred to as marinization, meaning the land-
based engine is modified for use in the marine environment. Marinization can be very complex or
relatively simple. Depending on the degree of change to the base engine, marinization can
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Regulatory Impact Analysis
significantly affect the emission characteristics of an engine. This will often be the case if the engine
fuel system or cooling systems are modified.
Some of the more complex changes associated with marinization are performed by large engine
manufacturers such as Caterpillar, Cummins, and Detroit Diesel. For these companies, marinization
may involve a significant redesign of their land-based product, including pistons, fuel systems,
cooling systems, and electronic controls. Actual production of marine engines often begins on the
same assembly line as the land-based counterparts. However, at some stage of the production
process the marine engine may be moved to a different assembly line or area, where production is
completed using parts and processes specifically designed for the marine derivative engine.
Post-manufacture marinizers will often make significant changes to base engines as part of the
marinization process. These companies purchase a complete or semi-complete land-based engine
from an engine manufacturer and finish or modify it using specially designed parts. The process is
often less complex, although fuel and cooling systems may be extensively modified. The finished
engine is often intended for niche applications.
A third type of marinization is performed by companies who purchase a completed engine from
an engine manufacturer and who modify it to make it compatible for installation on a marine vessel
without changing its underlying design characteristics or engine calibrations. These modifications
may involve changes to engine mountings, electronic instrumentation and alarm systems. These
companies, referred to here as engine dressers, may also add marine gears and couplings, in the case
of propulsion engines, or a generator in the case of auxiliary engines. In contrast to the other
marinization processes, these changes will not typically affect the emission characteristics of the
engine.
IV. Description of Engine Manufacturers
The companies that are most immediately affected by the proposed emission control program
are those that manufacture diesel marine engines. This section describes some of the main features
of these companies, with regard to their overall size and marine engine production volumes.
Manufacturers of each category of engines will be examined separately.
A. Sources of Information
The goal of an industry characterization is to describe the basic features of a particular engine
market segment as a whole, focusing on those features that may be helpful for or may become
potential obstacles to implementation of the proposed emission control program. In other diesel
engine rules, both on-highway and nonroad, EPA based its engine industry characterizations in large
part on information collected by Power Systems Research (PSR). This characterization of the marine
diesel engine industry also relies on PSR databases. However, for reasons described below, the PSR
databases are less helpful for describing this industrial segment. Therefore, EPA has augmented the
10
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Chapter 2: Industry Characterization
PSR data with information obtained through other sources, including trade journals and discussions
with various engine manufacturers.
The two PSR databases used by EPA in this industry characterization are the OE Link database
and the Parts Link database. Both of these depend on information provided to PSR by the engine
manufacturers. This can be an important drawback for relying on these databases when developing
a picture of the marine diesel engine market. Specifically, because they rely on self-reporting, very
small engine manufacturers may not be present in the databases.
Each of the two databases have additional weaknesses that affect EPA's ability to describe this
industry with a great deal of precision. The OE Link database contains data on U.S. engine
production for the years 1980 to 1997. While the overall production information is useful in
obtaining a picture of the potential impacts of the rulemaking on this industry, several features of this
database should be kept in mind. First, it includes only those companies that produce engines in the
United States. This is important because it means that engines that are imported into this country,
and that must be certified to the proposed emission limits, are not included. Second, it includes all
U.S. production, without differentiating between the engines that will be sold in this country, and
that must meet the proposed emission limits, and those that will be exported. Consequently, relying
on OE Link to paint a picture of the companies that may be affected by the proposed program may
result in an overestimate or underestimate of the magnitude of the potential impact of the rule.
The Parts Link database, on the other hand, contains information about the annual population
of marine diesel engines in the United States for the years 1990 to 1997. This database is useful
because it provides the names of all engine manufacturers, domestic and foreign, who have sold
engines into the U.S. fleet. The primary weakness of this database is that it does not yield annual
sales into the market for a given manufacturer. Instead, the annual information for each
manufacturer includes the cumulative engine sales over many years, with some internal accounting
for scrappage. Consequently, it does not help EPA determine which foreign manufactures are active
in the U.S. market at this time.
B. Category 1 Engines
1. Category 1 Engine Manufacturers
a) Identification of Domestic Producers
Using the PSR OE Link database, EPA assembled a list of companies who produce marine
diesel engines in the United States. These manufacturers, listed in Table 2-1, are grouped into four
categories. Domestic engine manufacturers (DEM) are companies who make fully-complete marine
engines. As described in the marinization discussion in Section HI above, these marine engines are
likely to be derived from one of the manufacturer's own land-based nonroad or on-highway engines.
Foreign engine manufacturers (FEM) are similar companies, but are owned by foreign companies.
Post-manufacturer marinizers (PMM) are companies that purchase a finished or semi-complete
engine from another engine manufacture and modify it for use in the marine environment. These
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Regulatory Impact Analysis
Figure 2-1
Figure 2-2
U.S. Diesel Marine Engine Production
Recreational Propulsion Engines
U.S. Diesel Marine Engine Production
Commercial Propulsion Engines
companies are broken down as to whether they make only an auxiliary engine or not, since those who
make only auxiliary engines are more likely to be engine dressers and therefore not required to
recertify their product to the proposed marine emission limits (see Section in.B.2 of the NPRM).
Table 2-1
Category 1 Engine Manufacturers
Source: PSR OE Link - U.S. Production Data
Domestic Engine
Manufacturers
Caterpillar
Cummins
Deere
Detroit Diesel
Foreign Engine
Manufacturers
Isuzu
Yanmar
Post-Manufacture
Marinizers - Propulsion
and Auxiliary
Alaska Diesel
Daytona Marine
Marine Corp. of Amer.
Marine Power
Onan
Outboard Marine
Peninsular Diesel
Trinity Marine
Westerbeke
Post-Manufacture
Marinizers -
Auxiliary only
Kohler
M&L Industries
R.A. Mitchell Co.
Star Power Services
Stewart & Stevenson
York
It should be noted that engine dressers are not specifically identified as such in the PSR
database, even though they are ostensibly producing marine diesel engines. Through contacts with
various engine manufacturers and its own efforts, EPA identified several of these companies.
Because of the special nature of their business, it is hard to precisely identify engine dressers; there
may therefore be tens if not hundreds of others. While an exact profile of the engine dressing
12
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Chapter 2: Industry Characterization
industry would be interesting, EPA believes it would be of limited value in this industry
characterization since provisions are being proposed that would exempt them from certification
requirements within certain constraints.
An interesting aspect of this industry revealed by the PSR data is that, although PMMs
outnumber EMs numerically, their production of propulsion engines is much smaller. Using data
on production volumes as reported in OE Link, it is possible to make several observations about the
production of marine engines. It should be remembered that these reflect total production, and not
just production intended for sale in the United States. However, these figures are nevertheless an
indicator of the basic make-up of the industry.
As illustrated in Figures 2-1 and 2-2, the majority of propulsion engines produced in the U.S.
are made by domestic engine manufacturers, even though the number of PMM companies exceeds
the number of large engine manufacturers. This is true for both commercial and recreational
propulsion engines.
In addition to producing more propulsion marine diesel engines, DEMs are also generally much
larger companies than PMMs. This is to be expected since PMM generally do not produce base
engines or serve markets outside of marine applications. The size difference between DEMs and
PMMs is confirmed by a financial analysis performed by ICF Incorporated using Dunn and
Bradstreet information. Of the eight large companies examined, five were DEMs and three were
PMMs. According to this analysis, the median large company has approximately 23,000 employees
and annual sales of $3.2 billion. All of the small companies observed were PMMs, and the median
small company has approximately 60 employees and annual sales of $19 million. Conversations
with various engine manufacturers also confirm the observation that PMMs are small companies.
Several, such as Peninsular, Alaska Diesel, and Daytona are family-owned business that operate on
a scale much smaller than the large engine manufacturers.
When auxiliary engines are considered,
however, the relationship between output and
engine sized is reversed. Specifically, PMMs
appear to produce more marine auxiliary marine
diesel engines than DEMs. In addition, as
illustrated in Figure 2-3, a large number of
auxiliary marine engines seem to be produced by
companies who specialize in auxiliary engines.
This, in turn, suggests that many of these engines
are assembled by engine dressers. There are at
least two explanations for this observation. It
could be the case that large engine manufacturers
do not get involved in the dressing process,
preferring to leave this to smaller companies who
can tailor their product to the special needs of
marine customers. Alternatively, it could be the
Figure 2-3
U.S. Diesel Marine Engine Production
Auxiliary Engines
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Regulatory Impact Analysis
case that the data on auxiliary engine productions for DEMs and FEMs is included in their land-
based nonroad figures instead of their marine figures.
b) Identification of Foreign Manufacturers
As indicated above, the PSR OE Link database contains information only on domestic producers
of marine diesel engines. Yet, foreign companies that sell engines in the United States may also be
affected by the proposed rule, and it is therefore important to identify them and estimate their share
of the domestic market. PSRParts Link population database contains a list of all the companies that
have engines in the current U.S. fleet. A list of those companies is contained in Table 2-2. Note
that, with regard to domestic engine manufacturers, Table 2-2 lists only the manufacturer of the base
engines. Thus, Navistar and GM are on the list from the population database (Parts Link) but not
on the production database (OE Link), since they do not produce a finished marine diesel engine.
This may be the case for some of the foreign engine manufacturers as well. It should also be noted
that the PSR Parts link database reflects manufacturers of engines that have been sold into the U. S.
market, and does not permit distinguishing between those that are still active in the market and those
that are not. The list also does not reflect those companies who seek to sell into the U.S. market, and
that will also be affected by the proposed emission control program.
Table 2-2
Category 1 Engine Manufacturers
Source: PSR Parts Link - U.S. Population Data
Domestic Engine
Manufacturers
Allis-Chalmers
Caterpillar
Cummins (including
Consolidated Diesel)
Deere
Detroit Diesel
Ford
GM (Chev/Pont/Can)
Navistar
Waukesha
Foreign
Bedford/AWD
Deutz-MWM
Hino
Isotta Fraschini
Isuzu
Komatsu
Kubota
Leyland
Lister-Fetter
Mack
MAN
Mazda
Mercedes Benz
MIT Motors
Engine Manufacturers
Mitsubishi HVY
MTU
New Holland
Perkins
PSA
Renault
Rover Cars
SACM
Scania
Steyr
Toyota
VM
Volvo
Yanmar
14
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Chapter 2: Industry Characterization
Figure 2-4
Figure 2-5
U.S. Diesel Marine Engine Population
Commercial Propulsion Engines
U.S. Diesel Marine Engine Population
Auxiliary Engines
Figure 2-6
Figure 2-7
U.S. Diesel Marine Engine Population
Recreational Propulsion Engines
U.S. Diesel Marine Engine Population
All Engines
The PSR Parts Link database suggests that the majority of Category 1 engines sold into the U.S.
domestic market, approximately 74 percent, were manufactured by domestic companies. The
remaining 26 percent were manufactured by foreign companies. This suggests that foreign
companies may have a considerable presence in the Category 1 engine market. When broken down
by engine category, this data suggests that the domination of DEMs is strongest in the recreational
category. These statements are illustrated in Figures 2-4 through 2-7 above. This data supports the
above observation suggested by the PSR OE Link database, that U.S. manufacturers have the
majority of the domestic diesel marine market.
15
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Regulatory Impact Analysis
c) Other Marine Diesel Engine Manufacturers
Finally, there are at least four other diesel marine engine manufacturers identified by EPA that
do not appear in the PSR databases. These are American Diesel, Mercury Marine, Norpro, and
Regan Equipment. It is EPA's understanding that each of these are PMMs, and therefore their
omission will not greatly affect the above observations about the characteristics of the marine diesel
engine market.
d) Conclusion
The above information suggests that the U.S. diesel engine industry is dominated by U.S.
manufacturers and that the large engine manufacturers produce the majority of the engines. PMMs
play a significant role in this market, although more so in the auxiliary engine market than in the
propulsion market. Foreign manufacturers are a smaller presence in the market, though they play
a larger role in commercial than in recreational applications.
2. Category 1 Engine Applications
With regard to the numbers of engines produced, the PSR OE Link database indicates total
annual production has varied over the past 17 years, from a low of 10,000 units in 1980 to a high of
nearly 20,000 units in 1988. Figure 2-8 illustrates that growth in this industry was interrupted in the
late 1980s and early 1990s. This may have been due to the economic recession in those years or
changes in the tax code, particularly from additional taxes on luxury goods.
Figure 2-8
Category 1 Engine Production
onnnn
^uuuu
* cnnn
IOUUU
* nnnn
IUUUU
cnnn
OUUU
19
/^^\^ ^-^
^^ Xv/ — -^
I I I I I I I
1981 1983 1985 1987 1989 1991 1993 1995 1997
80 1982 1984 1986 1988 1990 1992 1994 1996
Total Production
16
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Chapter 2: Industry Characterization
Figure 2-9 illustrates the portion of production for each segment of the industry, commercial
propulsion engines, recreational propulsion engines, and auxiliary engines. According to this chart,
auxiliary engines have had a fairly constant share of total production, increasing from about 7 percent
at the beginning of the period to about 12 percent at the end. The more important feature of the
shares of production concern propulsion engines. In the early 1980s, recreational engines replaced
commercial engines as the largest segment of production. This has been the case since then,
although production of these two types of propulsion engines was almost the same in the early 1990s.
Figure 2-9
Category 1 Engine Production
70%
60%
50%
40%
30%
20%
10%
0%
1981
1983
1980
1982
1984
1985 1987 1989
1986 1988
1990
1991 1993 1995
1992 1994
1997
1996
Aux Comm
Rec
C. Category 2 Engine Manufacturers
The greater mass and slower operating speeds of Category 2 engines generally corresponds with
better brake-specific fuel efficiency and longer total engine lifetime. Because of the large capital
requirements and the need to supply replacement parts over many years, companies with a long
history of supplying marine engines have a distinct advantage in the marketplace. Also, because of
the relatively low sales volume of these engines, producing engines for locomotives and for the
international marine market is also very important for broadening the sales base for distributing fixed
costs. Category 2 engine sales are therefore dominated by a small number of manufacturers.
General Motors Electromotive Division (EMD) has the longest history of supplying Category
2 marine engines and therefore produces the majority of these engines introduced into the U.S.
Caterpillar is also actively pursuing sales of Category 2 engines with a relatively new engine product.
Several other companies have engines available, but do not focus on the marine market. General
Electric sells the large majority of its engines only for locomotives, though some of these engines
17
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Regulatory Impact Analysis
find their way into marine vessels. Fairbanks Morse has long produced Category 2 marine engines,
but has shifted its focus to supplying engines into military applications, rather than the commercial
applications that would be most affected by the proposed standards. Several foreign companies
produce engines that could be sold into the U. S. market, though companies buying new vessels have
consistently specified U.S.-made engine models. This may change somewhat in the future,
especially considering the ongoing developments in joint ventures and other business arrangements.
Wartsila, MaK, MTU, Deutz, and Yanmar are some of the leading candidates for supplying engines
into the U.S.-flagged marine vessels.
Post-manufacture marinizers play an important role in producing Category 2 marine engines.
In the case of EMD engines, three authorized distributors take on the responsibility of marinizing
the engine, overseeing sales distribution, and managing installation and service as needed. Stewart
and Stevenson sells engines primarily into East Coast and Gulf states, while Valley Detroit Diesel
is responsible for West Coast sales. Inland sells Category 2 engines for states with Great Lakes and
inland river marine traffic.
Tugboats and towboats are the principal use of Category 2 marine engines. While tugboats
with total propulsive power up to about 2000 kW use multiple Category 1 engines, larger models rely
on one or two Category 2 engines. Similarly, the largest fishing vessels, ferries, and workboats use
these larger engines. These high-powered engines are used for carrying greater loads and, in many
cases, for more intensive operations. It is common for companies to own and operate small fleets
of these vessels. In addition, multiple Category 2 engines are commonly used for auxiliary power
on an ocean-going vessel.
With prices approaching $1 million for a new engine, there is a strong dependence on
maintaining and remanufacturing engines in the field. A strong preventive maintenance program is
the norm, often including extensive ongoing diagnostics for oil quality, fuel consumption, and other
engine performance parameters. Standard industry practice is to completely remanufacture the
engines every five years. Procedures have improved to the point that engine durability on
remanufactured engines is no different than on new engines. Since engine remanufacturing costs
only 20 to 30 percent as much as buying a new engine, even twenty- or thirty-year-old engines are
frequently overhauled to provide dependable power. The quality of remanufactured engines is so
good, and the price savings so great that it is even common practice to install remanufactured
engines into new marine vessels.
Another consequence of the prevalence of engine remanufacturing is the practice of reviving
retired locomotive engines for installation in new or used marine vessels. Since locomotive
operators have a higher sensitivity to achieving optimum performance and avoiding any downtime
resulting from repairs, engines no longer suitable for locomotive application can continue to serve
very well in several marine applications. Marine operations are generally less susceptible to
competitive pressures and can therefore maintain profitable operations with somewhat older
technology engines. Also, with predominantly local operation and an engineer onboard at all times,
there is less concern for expensive downtime due to part failures.
18
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Chapter 2: Industry Characterization
D. Category 3 Engine Manufacturers
There are currently no U.S. manufacturers of Category 3 marine engines for commercial
purposes. The Agency, however, has identified 22 foreign manufacturers of these engines, a large
fraction of which are located in Germany and Japan. Due to the competitive nature of this industry,
the number of manufacturers has changed over time due to mergers between companies. In addition,
of the Category 3 engine manufacturers identified, only 12 produce engines of their own design. The
remainder of the manufacturers produce engines under licensing agreements with other companies
that control engine design. Table 2-3 presents the Category 3 engine manufacturers identified by
EPA. These manufacturers are divided by those that produce their own designs and those that solely
produce licensed designs. In many cases, the manufacturer names are hyphenated which generally
is the result of a merger between two or more companies.
Table 2-3
Manufacturers of Category 3 Marine Diesel Engines
Produce Own Designs
Produce Engines Using Licensed Designs
Akasaka
Allen Diesel
Daihatsu
Deutz-MWM
Fincantier Group/GMT
Hanshin
MAN-B&W
MaK
Matsui Iron Works
Mitsubishi Heavy Ind. LTD
SEMT-Pielstick
Wartsila-NSD
Bazan
Cegielski
Coltec Industries
Dieselmotorenwerk Vulcan GMBH
Jadranbrod ULJANK
Kawasaki Heavy Ind.
Kirloskar Oil Engines Ltd.
Koloma Plant Joint Stock
Maschinenbau Halberstadt
Niigata
V. Recreational Boat Builders
A. Introduction
The second set of companies that is potentially affected by the proposed controls on diesel
marine engines is the group of companies that manufacture marine vessels. In general, the
companies that manufacture vessels would not be directly responsible for ensuring that the engines
they install meet the proposed emission control requirements. However, they are potentially affected
by the proposed rule to the extent that physical changes to the engines require changes to their vessel
designs.
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Regulatory Impact Analysis
This section contains a brief description of the recreational vessel market. Since the Agency
is not proposing regulations for this sector of the industry at this time, the following discussion is
provided to support the decision to defer requirements for recreational engines until a subsequent
rulemaking. This description of this industry segment focuses on the number and location of
recreational vessel builders, industry sales information, the types of vessels made by these
companies, and the types of engines they use. The commercial vessel market is described in the
following section.
B. Identification and Location of Builders
EPA considered several sources, including trade associations and Internet Web sites when
identifying entities that build and/or sell recreational vessels. This resulted in a list of 165
manufacturers that build and/or sell recreational vessels. However, not all of these companies offer
a version of their product using a diesel engine. Discussions with industry representative narrowed
this list down to 73 companies that offer a diesel engines in their product lines. Overall, diesel
engines do not constitute the majority of product offerings for the 73 companies. While, for some,
diesels account for a majority of sales, others may sell as few as one per year or may sell a diesel
version once every several years. This implies that this regulation will not affect all companies in
the same way. Not surprisingly, the analysis shows that recreational vessel building is concentrated
in coastal states with the largest presence in the state of Florida.
C. Sales and Employment Figures
To gain a better understanding of the nature of companies that participate in this industry, EPA
was able to obtain financial and employment information for 51 of the 73 companies from Dunn &
Bradstreet and through contact with individual companies. D&B data was not available for the
remaining 22 companies. Of the recreational boat builders installing CI marine engines evaluated
by the Agency, four companies reported annual sales of their products ranging from 95 million to
3.0 billion dollars. The next group of companies reported annual sales ranging from 10 million to
70 million dollars. The last range of companies reported annual sales ranging from 1.5 million to
8 million dollars. The lower range of companies reported annual sales of around 100,000 dollars.
The largest company employs 21,000. The next highest range of companies employ 8,000 and
5,000, but a majority of the companies identified in our sample employ less than 500, with average
being around 130. Of the 51 companies for which the Agency has information, 47 companies
employed less than 500. The Small Business Administration (SBA) has developed standards by
which to define a small business. According to the SBA, for the boat building and repairing
industry, a company is defined as small if it employees less than 500. Using this definition, 92
percent of the companies researched by the Agency would be considered small business.
20
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Chapter 2: Industry Characterization
Table 2-4
Sales and Employment Data for
Recreational Boat Builders Using Diesel Engines
Number of
Companies
15
13
19
4
Annual
Sales
$93,300 -$890,000
$1.3 million - $9.6 million
$10 million -$70 million
$95 million -$3.0 billion
Number of
Employees
1-12
12-60
60-500
1000-21000
D. Production Practices
Based on information supplied by a variety of recreational boat builders, the following
discussion provides a description of the general production practices used in this sector of the
marine industry.
Engines are usually purchased from factory authorized distribution centers. The boat builder
provides the specifications to the distributor who helps match an engine for a particular application.
It is the boat builders responsibility to fit the engine into their vessel design. The reason for this is
that sales to boat builders are a very small part of engine manufacturers' total engine sales. These
engines are not generally interchangeable from one design to the next. Each recreational boat
builder has their own designs. In general, a boat builder will design one or two molds that are
intended to last 5-8 years. Very few changes are tolerated in the molds because of the costs of
building and retooling these molds.
E. Gasoline Engine vs. Diesel Engine Installation in Recreational Vessels in the U.S.
Based on information obtained from the National Marine Manufacturers Association, the largest
majority of engines used for recreational marine purchases are gasoline powered engines. Of the 75
companies submitting data for their 1996 annual survey of the recreational marine industry, 65,653
gasoline engines were installed vs. 1,381 diesel engines. Of the 1,381 diesel engines installed, 53
percent of these engines were installed in boats over 41 feet long. Of the 90 companies that
submitted data for the 1997 survey, 80,339 gasoline engines were installed compared to 1,752 diesel
engines. Of the 1,752 diesel engines, 57 percent were installed in boats over 41 feel long.
21
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Regulatory Impact Analysis
Table 2-5
1996 and 1997 U.S. Sales of Gasoline and Diesel Recreational Engines
Length
25' & Under
26'-30'll"
31'-35'11"
36'-40'll"
41' & over
Totals
Gasoline
1996
53,844
7,836
2,899
875
199
65,653
1997
71,304
4,905
2,919
805
406
80,339
Diesel
1996
5
90
223
330
733
1,381
1997
12
125
237
378
1,000
1,752
Overall, diesel engines comprise a relatively small portion of the engines installed and used for
recreational purposes.
VI. Commercial Vessel Builders
A. Introduction
The industry characterization for the commercial marine vessel industry was developed by ICF
Incorporated under contract for EPA. Following is a summary of their findings. A complete copy
of this report is available from EPA Air Docket A-97-50.
There are three main parts to this report. Parts one and two establish the location, number, size,
and relevant factors associated with shipbuilding and boat building. Part three covers production
practices commonly employed by shipbuilders and boat builders.
B. Vessel Types
The report makes a distinction between two broad groups of commercial vessels, "ships" and
"boats," based on a vessel's basic dimensions, mission and area of operation.
- Commercial Ships - this category is comprised of larger merchant vessels, usually
exceeding 400 feet in length, that engage in waterborne trade and/or passenger transport. These
ships tend to operate in Great Lakes, coastwise, inter-coastal, non-contiguous, and/or transoceanic
routs. Principle commercial ship types are dry cargo ships, tankers, bulk carriers and passenger
ships. Passenger ships include cruise ships and larger ferries.
22
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Chapter 2: Industry Characterization
- Commercial Boats - This category is comprised of smaller service and industrial vessels
less than 400 feet in length that provide service to commercial ships, industrial vessels, and/or barges
that perform specialized marine functions. Commercial boats are found mainly in inland and coastal
waters. Principle commercial boat types are tugboats, towboats, offshore supply boats, fishing and
fisheries vessels, passenger boats, and industrial boats. Passenger boats include crewboats,
excursion boats, and smaller ferries.
C. Shipbuilders
1. Production Information and Industry Drivers
The vast majority of commercial ships are foreign built. Currently, the U. S. holds less than one
half of one percent of the world market share of commercial shipbuilding and repair. The late 1970s
and early 1980s reflect a worldwide boom in shipbuilding, particularly in energy-related vessels such
as oil drill rigs and tankers. With falling oil prices in the 1980's, there was a substantial decline in
commercial vessel orders throughout the world. No commercial orders were placed at U.S.
shipyards for 1987 through 1989. In the 1990s, however, the rate of orders has slowly increased to
the current rate of approximately 16 ships per year.
2. Location and Number of Builders
There are currently only 18 major shipbuilding facilities in the United States. Most of the
facilities are located on the East and Gulf Coasts. The Gulf Coast is a particularly attractive location
for shipbuilders due to the relatively low labor costs for the region. New Orleans and Houston lead
the U.S. in international trade tonnage.
3. Size and Sales Profile
The six largest companies in the shipbuilding industry in terms of employment and sales
revenue are represented by The American Shipbuilding Association (ASA). Almost all commercial
ships currently manufactured in the U.S. constructed at an ASA yard. These six companies employ
nearly 55,000 people, representing 90 percent of new ship construction employment in the U.S.
Additionally, five of the yards are the largest employers in their states. Sales revenue for these six
companies is estimated at approximately $5.2 billion dollars annually.
4. Outlook
Worldwide, the demand for ships is expected to increase during the next decade. Chartering
companies and class societies are tightening their requirements. Insurance will become increasingly
expensive for older tonnage. Tighter safety regulations will force single-hulled and 30-year old oil
tankers out of the market. These collective forces are expected to create a market momentum in
which new vessels may be more attractive.
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Regulatory Impact Analysis
In sum, the gains due to the anticipated U.S. market growth in commercial shipbuilding are
expected to be modest. During the next decade, U.S. shipyards are projected to lose 28,000 jobs as
a result of the cut in military orders. This shift in the government market may result in U. S. Shipyard
closings or conversions to repair facilities or even non-shipbuilding projects as they have during the
lean years. Recent reports by market analysts also suggest a tempered shipbuilding outlook due to
the financial crisis in Asia. Any increases in U.S. shipbuilding is likely to be modest.
D. Boat Builders
1. Production and Industry Drivers
Because of Jones Act requirements, the vast majority of boats used in the U.S. are U.S. made.
According to WorkBoat Magazine's annual construction survey, 569 commercial boats were ordered
in 1997, approximately 100 more than were reported in both 1995 and 1996. While these estimates
rely upon survey responses, WorkBoat Magazine's 1995 estimates closely compare with another
industry journal, Seatrade Review.
The U. S. boatbuilding industry is currently influence by four key factors: increasing demand for
T class vessels, increasing demand for offshore supply vessels, increasing demand for oil, and the
expansion of demand for casino boats. For further analyses of these factors, see section 3.1 of the
ICF report.
2. Boat Types and Customers
U.S. boatbuilders construct a wide variety of commercial boats less than 400 feet in length.
Most of these yards are small and manufacture small and/or less complex boat designs. A few of
the yards have the capacity to build more advanced boats, and some also have the capacity to build
small ships. U.S. Boatyards build boats primarily used on inland and coastal waterways between
U.S. ports. Such vessels must satisfy Jones Act requirements and, therefore, be built in the United
States. For this reason, the U. S. boat building industry has a protected local market and does not face
the intense foreign competition that U.S. shipbuilders do.
3. Location and Number of Builders
In contrast to the highly concentrated shipbuilding industry, there are several hundred yards that
build many different types of boats. Using various sources of information including Duns and
Bradstreet databases, industry magazines, and Internet searches, ICF estimated that there are
approximately 430 firms that engage in boat building. A majority of the boat builders are located
in the Gulf Coast, the Northeast, and the West Coast. The number of boatbuilders in these three
regions account for approximately 30 percent, 26 percent and 25 percent of the boat building
industry, respectively.
24
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Chapter 2: Industry Characterization
4. Size and Sale Profile
Given the large number of companies in the Boatbuilder Database, it was not possible to contact
each one to gather size and sales information. Therefore, two boatbuilders were contacted from the
top, middle, and bottom third of the boatbuilder database based on the total employment for the
company, including subsidiaries. For specific information on the size and sales of boatbuilders, see
section 3.4 of the ICF report as referenced in the introduction of this section.
5. Applications by Geographic Location
A majority of boatbuilders are located in the Gulf Coast, the Northeast, and the West Coast.
Collectively, these three regions represent 345 boatbuilders, or 80 percent of all companies in the
Boatbuilder Database.
The Gulf Coast is currently the leader in boat production, outperforming the east and west coasts
due to advantages in weather, production automation, favorable labor rates and relatively
inexpensive real estate. Approximately 30 percent of all boatbuilders are located in the Gulf Coast.
Overall, roughly 35 percent of the yards that build industrial boats, tugboats, ferries and passenger
boats are located in this region.
The Northeast comprises about 25 percent of the firms in the database. Compared with yards
located in the Gulf Coast and the South Atlantic, a boatbuilder in the north is 20 to 25 percent more
expensive, taking into account both labor and operating costs. Few of these Northeastern yards build
industrial boats, tugboats, ferries, and passenger boats. However, nearly 70 percent of the yards that
build fishing boats are located in this region.
The West is primarily dedicated to highly specialized boat yards. For example, boatbuilder in
this region construct vessels such as processor catchers, tuna clippers, and small aluminum brine
shrimp boats. About 25 percent of the firms in the database are located in the West, including 30
percent of all firms that build fishing boats and nearly 42 percent of the firms that build industrial
boats, tugboats, ferries, and passenger boats.
ICF also identified 156 small boat builders that employ fewer than 20 workers, based on total
company employment. These yards primarily repair and build small boats less than 55 feet in length
which are used in fishing applications such as lobster, oyster, and crab boats.
6. Very Small Boat Builders
ICF identified 182 small boatbuilders that employ fewer than 20 workers, based on total
company employment. These yards primarily repair and build small boats less than 55 feel in length,
which are used in numerous fishing applications. Such applications include lobster, oyster, and crab
boats. Production of these vessels requires smaller facilities and fewer employees. Vessel
production at these yards is cyclical, which in part explains why the primary source of revenue for
most small yards is repair services.
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Regulatory Impact Analysis
According to ICF, little data exists on how many of these small vessels are manufactured
annually. However, the production of small fishing vessels is extremely regional. Generally, local
demand looks to local builders for vessel production.
Additionally, some small yards do assemble tugs, particularly for inland use. Tugs are
technically less difficult to develop than other types of boats and their designs have not changed
much over time.
7. Outlook
Decisions by leading boatbuilders to reopen facilities and expand their labor forces are strong
indications that market growth for commercial boatbuilding is expected to be considerable. The
extent that smaller boatbuilders realize the same level of growth is uncertain. If the commercial
boatbuilding industry continues to grow at approximately the same pace maintained over the last
decade, the overall demand for new boats may mean more business for even the smallest yards.
Demands for new boats in the U.S. will likely be in "hot markets" such as T class vessels,
offshore supply vessels, drillships and semisubmersible rigs, and casino boats. For this reason, the
projected increase in demand for new boats will more business for the U.S. boating industry, as
foreign builders are ineligible to build for this market.
In sum, U.S. boatbuilders are expected to continue to be a major consumer of marine diesel
engines. If market increases are realized, the number of marine diesel units used in the boatbuilding
industry may increase substantially.
26
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Chapter 2: Industry Characterization
Chapter 2 References
1. Federal Register, "Control of Emissions of Air Pollution from Nonroad Diesel Engines;
Proposed Rule," pp. 50151-50219, September 24, 1997.
2. Federal Register, "Emission Standards for Locomotives and Locomotive Engines; Final
Rule," pp. 18978-19084, April 16, 1998.
3. Boating Industry Magazine, "1997 Annual Industry Reviews: The Boating Business", January
1998.
4. "Diesel & Gas Turbine Worldwide Catalog: Product Directory and Buyers Guide," 1997
Edition, Volume 62.
5. Dunn & Bradstreet.
6. National Marine Manufacturers Association -http://209.94.233.3/iww/customers/nmma/.
7.. National Marine Manufacturers Association - "Monthly Statistical Report of the Recreational
Marine Industry," July 1997.
8. National Marine Manufacturers Association - "Monthly Statistical Report of the Recreational
Marine Industry, " July 1996.
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Regulatory Impact Analysis
28
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Chapter 3: Technological Feasibility
CHAPTER 3: TECHNOLOGICAL FEASIBILITY
I. Introduction
The purpose of this chapter is to discuss the feasibility of achieving significant reductions in
exhaust emissions from marine diesel engines. Because marine diesel engines are often derived from
or use the same technologies as land-base engines, EPA believes that the marine industry will be able
to capitalize on the technological improvements being made to land-based diesel engines and achieve
similar emission reductions.
This chapter covers a wide range of areas that affect the technological feasibility of this rule.
It begins with a rudimentary description of the classifications and applications of marine engines as
well as the marinization process. This is followed by an overview of emission formation from diesel
engines. Then, established diesel emission control technologies will be described, which EPA
believes can be used on marine diesel engines to meet the proposed standards. Next, the proposed
emission test procedures that will be used to measure and assess the impacts of the proposed
emission levels will be discussed. This will be followed by a description of baseline technologies
currently used on marine diesel engines and a discussion of developing emission control strategies
and results achieved from various low-emission marine engine designs. Finally, this chapter presents
the most likely technology mix that EPA believes would result from putting the proposed Tier 2 and
Tier 3 standards into place for marine diesel engines.
II. Marine Diesel Engine Design Ratings
Broadly speaking, the rating of an engine refers to the type of operating conditions the engine
is designed to handle. For marine diesel engines, engine ratings also roughly correspond to how the
engine is intended to be used, for primarily recreational or some type of commercial application.
These are described in greater detail below.
A. High Performance Ratings: Recreational Marine Engines
High performance engines are generally intended for light-use recreational marine purposes.
The high performance rating varies by manufacturer but generally means that the engines are
designed to maximize the power-to-weight ratio. In other words, they are designed for maximum
performance while minimizing the space needed on the boat for the engine and minimizing the added
weight of the engine. Because the purpose of these engines is to get high power from a small engine,
they are not built to withstand long periods of operation at rated power. For planing vessels, the
engine only needs the high power until the vessel is raised to the surface of the water, then a much
lower power is used for cruising. Marine engines with a high performance rating are generally
designed to be operated a maximum of 200 to 1000 hours per year. They are intended for variable
29
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Regulatory Impact Analysis
load applications where the engine operates at full power no more than 15 minutes at a time and
where the engine would only spend one out of every eight to twelve hours at full load. These engines
are typically Category 1 engines.
B. Other Ratings: Commercial Marine Engines
Light duty commercial engines have many of the same characteristics as the recreational
engines, except that they are designed to be more durable and thus more attractive for commercial
applications. Greater durability is achieved by using a heavier engine design for a given power
rating. Although these engines are still only designed to be operated one hour out of every six to
eight hours at high power, they are intended to be used anywhere from 750 to 3000 hours per year,
for active seasonal to annual use. Light duty commercial engines are usually used in boats with
planing hulls such as, seasonal fishing vessels and emergency rescue boats, or to power bow thrusters
on larger vessels. While they can also be used in recreational applications, this is typically on larger
vessels that need more power to achieve planing or are intended to be used more than just
occasionally. These engines are typically Category 1 engines.
Intermittent duty commercial rated engines are intended for use in boats with either planing or
displacement hulls that are used under variable speeds and loads. These engines are designed to
operate at full load no more than half of the time for 2000 to 4000 hours per year. Typical
applications for intermittent duty engines would be commercial fishing boats, ferries, and coastal
freighters. In addition, most auxiliary marine engines would fall into this category. Again, the use
of these engines is not exclusively commercial, and they can be used on large displacement hull
yachts. Intermittent duty engines are typically Category 1 engines, but may include some Category
2 engines.
Marine engines with a medium continuous rating are designed to operate a large number of
hours at fairly constant speeds and loads on vessels with displacement hulls. These engines are
recommended for applications where the engine would be operated from 3000 to 5000 hours per year
(60-100 hours per week), but spend no more than about 80 percent of the time at full load. The
advantages of this design are good durability and fuel consumption while still maintaining some
performance benefits. These engines may be found in applications such as crew and supply boats,
trawlers, and tow boats. Large auxiliary engines generally would fall into this rating as well. This
rating would include mostly Category 2 engines with some Category 1 engines.
Marine engines with a continuous rating are designed to operate under full load 24 hours per
day and generally are operated more than 5000 hours per year. These engines are designed to
maximize durability and fuel efficiency which results in low operating costs. Typical applications
for marine engines with a continuous rating range from tug boats to ocean-going vessels. Tug boat
applications would still likely use Category 2 engines, but the majority of the ocean-going vessels
would use Category 3 engines.
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Chapter 3: Technological Feasibility
III. The Marinization Process
As noted in the previous chapter, marine engines are not generally built from the ground up as
marine engines. Instead, they are often marinized land-based engines. The following is a brief
discussion of the marinization process, as it is performed by either engine manufacturers or post-
manufacture marinizers (PMM).
The most obvious changes made to a land-based engine as part of the marinization process
concern the engine's cooling system. Marine engines generally operate in closed compartments
without much air flow for cooling. This restriction can lead to engine performance and safety
problems. To address engine performance problems, these engines make use of the ambient water
to draw the heat out of the engine coolant. To address safely problems, marine engines are designed
to minimize hot surfaces. One method of ensuring this, used mostly on recreational or light duty
commercial engines, is to run cooling water through a jacket around the exhaust system and the
turbocharger. Larger engines generally use a thick insulation around the exhaust pipes. Hardware
changes associated with these cooling system changes often include water jacketed turbocharger s,
water cooled exhaust manifolds, heat exchangers, sea water pumps with connections and filters, and
marine gear oil coolers. In addition, because of the greater cooling involved, it is often necessary
to change to a single-chamber turbocharger, to avoid the cracking that can result from a cool outer
wall and a hot chamber divider.
Other important design changes are related to engine performance. Especially for planing hull
vessels used in recreational and light duty commercial marine applications, manufacturers strive to
maximize the power-to-weight ratio of their marine engines, typically by increasing the power from
a given cylinder displacement. The most significant tool to accomplish this is the fuel injection
system: the most direct way to increase power is to inject more fuel. This can require changes to the
camshaft, cylinder head, and the injection timing and pressure. Currently, the design limits for
increased fuel to the cylinder are smoke and durability. Modifications made to the cooling system
also help enhance performance. By cooling the charge, more air can be forced into the cylinder. As
a result, more fuel can be injected and burned efficiently due to the increase in available oxygen.
In addition, changes are often made to the pistons, cylinder head components, and the lubrication
system. For instance, aluminum piston skirts may be used to reduce the weight of the pistons.
Cylinder head changes include changing valve timing to optimize engine breathing characteristics.
Increased oil quantity and flow may be used to enhance the durability of the engine.
Marinization may also involve replacing engine components with similar components that are
made of materials that are more carefully adapted to the marine environment. Material changes
include more use of chrome and brass including changes to electronic fittings to resist water induced
corrosion. Zinc anodes are often used to prevent engine components, such as raw-water heat
exchangers, from being damaged by electrolysis.
Depending on the stage of production and the types of changes made, the marinization process
can have an impact on the base engine's emission characteristics. In other words, land-based engine
that meets a particular set of emission limits may no longer meet these limits after it is marinized.
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This can be the case, for example, if the fuel system is changed to enhance engine power or if the
cooling system no longer achieves the same degree of engine cooling as that of the base engine.
Because marine diesel engines are currently unregulated, engine manufacturers have been able to
design their marine engines to maximize performance, often obtaining power/weight ratios much
higher than land-based applications. The challenge presented by the proposed emission control
program will be to achieve the emission limits while maintaining these favorable performance
characteristics.
IV. Background on Diesel Emission Formation
In a diesel engine, the liquid fuel is injected into the combustion chamber after the air has been
heated by compression (direct inj ection), or the fuel is inj ected into a prechamber, where combustion
initiates before spreading to the rest of the combustion chamber (indirect injection). The fuel is
injected in the form of a mist of fine droplets or vapor that mix with the air. Power output is
controlled by regulating the amount of fuel inj ected into the combustion chamber, without throttling
(limiting) the amount of air entering the engine. The compressed air heats the inj ected fuel droplets,
causing the fuel to evaporate and mix with the available oxygen. At several sites where the fuel
mixes with the oxygen, the fuel auto-ignites and the multiple flame fronts spread through the
combustion chamber.
NOx and PM are the emission components of most concern from diesel engines. Incomplete
evaporation and burning of the fine fuel droplets or vapor result in emissions of the very small
particles of PM. Small amounts of lubricating oil that escape into the combustion chamber can also
contribute to PM. Although the air/fuel ratio in a diesel cylinder is very lean, the air and fuel are not
a homogeneous charge as in a gasoline engine. As the fuel is injected, the combustion takes place
at the flame-front where the air/fuel ratio is near stoichiometry. At localized areas, or in cases where
light-ends have vaporized and burned, molecules of carbon remain when temperatures and pressures
in the cylinder become too low to sustain combustion as the piston reaches bottom dead center.
Therefore, these heavy products of incomplete combustion are exhausted as PM.
High temperatures and excess oxygen are necessary for the formation of NOx. These
conditions are found in a diesel engine. Therefore, the diesel combustion process can cause the
nitrogen in the air to combine with available oxygen to form NOx. High peak temperatures can be
seen in typical unregulated diesel engine designs. This is because the fuel is injected early to help
lead to more complete combustion, therefore, higher fuel efficiency. If fuel is injected too early,
significantly more fuel will mix with air prior to combustion. Once combustion begins, the
premixed fuel will burn at once leading to a very high temperature spike. This high temperature
spike, in turn, leads to a high rate of NOx formation. Once combustion begins, diffusion burning
occurs while the fuel is being injected which leads to a more constant, lower temperature,
combustion process.
Because of the presence of excess oxygen, hydrocarbons evaporating in the combustion chamber
tend to be completely burned and HC and CO are not emitted at high levels. Evaporative emissions
from diesel engines are insignificant due to the low evaporation rate of diesel fuel.
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Controlling both NOx andPM emissions requires different, sometimes opposing strategies. The
key to controlling NOx emissions is reducing peak combustion temperatures since NOx forms at
high temperatures. In contrast, the key to controlling PM is higher temperatures in the combustion
chamber or faster burning. This reduces PM by decreasing the formation of particulates and by
oxidizing those particulates that have formed. To control both NOx and PM, manufacturers need
to combine approaches using many different design variables to achieve optimum performance.
These design variables are discussed below.
V. General Description of Emission Control Strategies
EPA believes that the proposed standards for diesel marine engines can be met using technology
that has been developed for and used on locomotive, land-based nonroad, and on-highway engines.
This section discusses technology used successfully on diesel engines to reduce exhaust emissions,
including combustion optimization, better fuel control, improved charge air characteristics, exhaust
gas recirculation, and aftertreatment. A more detailed analysis of the application of several of these
technologies to marine engines is discussed later in this chapter. The costs associated with applying
these systems to marine engines are considered in the next chapter.
A. Combustion Optimization
Several parameters in the combustion chamber of a heavy-duty diesel engine affect its efficiency
and emissions. These engine parameters include injection timing, combustion chamber geometry,
compression ratio, valve timing, turbulence, injection pressure, fuel spray geometry and rate, peak
cylinder temperature and pressure, and charge (or intake) air temperature and pressure. Many
technologies that are designed to control the engine parameters listed above have been investigated.
As mentioned previously, however, a positive influence on one pollutant may have a negative
influence on another. For example, charge air cooling reduces NOx emissions, but increases PM.
Manufacturers will need to integrate all of these variables into optimized systems to meet the
proposed standards.
1. Timing retard
The effect of injection timing on emissions and performance is well established.1'2'3'4 Retarded
timing will most likely be used at cruising speeds where propulsion marine engines spend most of
their operating time. NOx is reduced because the premixed burning phase is shortened and because
cylinder temperature and pressure are lowered. Timing retard increases HC, CO, PM, and fuel
consumption, however, because the end of injection comes later in the combustion stroke where the
time for extracting energy from fuel combustion is shortened and the cylinder temperature and
pressure are too low for more complete oxidation of PM. One technology that can offset this trend
is higher injection pressure, which is discussed further below.
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Regulatory Impact Analysis
2. Combustion chamber geometry
While manufacturers are already achieving emission reductions through modifications to the
combustion chamber, EPA believes there are additional changes that may provide further
improvements in emission control. The parameters being investigated include (1) the shape of the
chamber and the location of injection; (2) reduced crevice volumes; and (3) compression ratio.
These parameters have been thoroughly explored for highway engines and should be readily
adaptable to nonroad and marine engines.
Efforts to redesign the shape of the combustion chamber and the location of the fuel inj ector for
highway and nonroad engines have been primarily focused on optimizing the relative motion of air
and injected fuel to simultaneously limit the formation of both NOx and PM. Piston crown design
must be carefully matched with injector spray pattern and pressure for optimal emission behavior.5
One strategy, reentrant piston bowl design, focuses on optimizing the radius of the combustion bowl,
the angle of the reentrant lip, and the ratio of the bowl diameter to bowl depth to optimize air motion.
An alternative is the use of higher pressure injection systems that decrease the need for turbulent in-
cylinder charge air motion. While higher pressure systems raise concerns of durability, there has
been a significant amount of progress in this area and it is expected that manufacturers will be able
to develop a durable system.6
The second parameter being investigated is reducing crevice volumes by moving the location
of the top piston ring relative to the top of the piston.7 A reduced crevice volume can result in
reduced HC emissions and, to a lesser extent, reduced PM emissions. Costs associated with the
relocation of the top ring can be substantial because raising the top of the piston ring requires
modified routing of the engine coolant through the engine block and lube oil routing under the piston
to prevent the raised ring from overheating. It is also important to design a system that retains the
durability and structural integrity of the piston and piston ring assembly, which requires very precise
tolerances to avoid compromising engine lubrication.
Compression ratio is another engine design parameter that impacts emission control. In general,
higher compression ratios cause a reduction of cold start PM and improved fuel economy, but can
also increase NOx. Several methods can be employed to increase the compression ratio in an
existing diesel engine. Redesign of the piston crown or increasing the length of the connecting rod
or piston pin-to-crown length will raise the compression ratio by reducing the clearance volume.8
There is a limit to the benefit of higher compression ratios because of increased engine weight (for
durability) and frictional losses, which could somewhat limit fuel economy improvements.
3. Swirl
Increasing the turbulence of the intake air entering the combustion chamber (i.e., inducing swirl)
can reduce PM by improving the mixing of air and fuel in the combustion chamber. Historically,
swirl was induced by routing the intake air to achieve a circular motion in the cylinder.
Manufacturers are, however, increasingly using "reentrant" piston designs in which the top surface
of the piston is cut out to allow fuel injection and air motion in a smaller cavity in the piston to
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Chapter 3: Technological Feasibility
induce additional turbulence. Manufacturers are also changing to four valves per cylinder, which
reduces pumping losses and can also allow for intake air charge motion. The effect of swirl is often
engine-specific, but some general effects may be discussed.
At low loads, increased swirl reduces HC, PM, and smoke emissions and lowers fuel
consumption due to enhanced mixing of air and fuel. NOx emissions might increase slightly at low
loads as swirl increases. At high loads, swirl causes slight decreases in PM emissions and fuel
consumption, but NOx may increase because of the higher temperatures associated with enhanced
mixing and reduced wall impingement.9 A higher pressure fuel system can be used to offset some
of the negative effects of swirl, such as increased NOx, while enhancing the positive effects such as
a reduction in PM.10
B. Advanced Fuel Injection Controls
Control of the many variables involved in fuel injection is central to any strategy to reduce
diesel engine emissions. The principal variables being investigated are injection pressure, nozzle
geometry (e.g., number of holes, hole size and shape, and fuel spray angle), the timing of the start
of injection, and the rate of injection throughout the combustion process (e.g., rate shaping).
Manufacturers continue to investigate new injector configurations for nozzle geometry and
higher injection pressure (in excess of 2300 bar (34,000 psi)).11'12 Increasing injection pressure
achieves better atomization of the fuel droplets and enhances mixing of the fuel with the intake air
to achieve more complete combustion. Though HC and PM are reduced, higher cylinder pressures
can lead to increased NOx formation.13 However, in conjunction with retarding the start of fuel
injection, higher fuel injection pressures can lead to reduced NOx because of lower combustion
temperatures. HC, PM, or fuel economy penalties from this strategy can be avoided because the
termination of fuel injection need not be delayed. Nozzle geometry is used to optimize the fuel spray
pattern for a given combustion chamber design in order to improve mixing with the intake air and
to minimize fuel condensation on the combustion chamber surfaces.14 Minimizing the leakage of
fuel droplets is critical for reducing HC emissions. Valve-closed orifice (VCO) tips are more
effective than sac-type nozzles, because they eliminate any droplets remaining after injection, which
would increase HC emissions. Although VCO tips are subject to very high pressures, EPA believes
progress will continue in developing a durable injector tip prior to implementation of these standards.
The most recent advances in fuel injection technology are the systems that use rate shaping or
multiple injections to vary the delivery of fuel over the course of a single injection. Igniting a small
quantity of fuel initially limits the characteristic rapid increase in pressure and temperature that leads
to high levels of NOx formation. Injecting most of the fuel into an established flame then allows for
a steady burn that limits NOx emissions without increasing PM emissions. Rate shaping may be
done either mechanically or electronically. Rate shaping has been shown to reduce NOx emissions
by up to 20 percent.15
For electronically controlled engines, multiple injections may be used to shape the rate of fuel
injection into the combustion chamber. Recent advances in fuel system technology allow high-
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Regulatory Impact Analysis
pressure multiple injections to be used to reduce NOx by 50 percent with no significant penalty in
PM. Two or three bursts of fuel can come from a single injector during the injection event. The
most important variables for achieving maximum emission reductions with optimal fuel economy
using multiple injections are the delay preceding the final pulse and the duration of the final pulse.16
This strategy is most effective in conjunction with retarded timing, which leads to reduced NOx
emissions without the attendant increase in PM.
A promising fuel injection design is that developed by Caterpillar and Navistar, the
Hydraulically actuated Electronically controlled Unit Inj ection (HEUI) system.17'18 The HEUI system
utilizes a common rail of pressurized oil to provide high injection pressures of 175 MPa (25,000 psi)
throughout an engine's operating range. The HEUI system provides full electronic control of
inj ection timing and duration, along with the possibility for rate shaping. The most attractive aspect
of this system is that it operates largely independent of engine speed so that the engine can be
optimized over a larger range of operation. Some marine engine manufacturers are already utilizing
this system on production engines. It is expected that manufacturers will be able to develop and
produce a full-authority electronic fuel injection system for a reasonable cost in time for these
standards. For larger engines (> 1.5 liters/cylinder), Caterpillar has designed a Mechanically actuated
Electronically controlled Unit Injection (MEUI) system. MEUI is similar to HEUI in that it can
control injection pressure, timing and rate shaping independent of engine speed. Caterpillar has
reported injection pressures as high as 200 MPa (30,000 psi) with the MEUI system.
Common rail fuel systems may be used to gain fuel injection improvements over distributer
pump type systems. Fuel is pressurized in the fuel rails which allows high pressures independent
of engine speed. Cummins has recently developed an alternative technology known as the Cummins
Accumulator Pump (CAP) fuel system.19'20 The CAP system uses an accumulator between the high
pressure fuel injection pump and the distributor to achieve high pressure fuel injection of 145 MPa
(21,000 psi) and control timing independent of engine speed. This system offers a low cost
alternative to common rail fuel injection.
C. Improving Charge Air Characteristics
Charge air compression (turbocharging) is primarily used to increase power output and reduce
fuel consumption from a given displacement engine. At rated power, a typical diesel engine loses
about 30 percent of its energy through the exhaust. A turbocharger uses the waste energy in the
exhaust gas to drive a turbine linked to a centrifugal compressor, which then boosts the intake air
pressure. By forcing more air into the cylinder, more fuel can also be added at the same air-fuel
ratio, resulting in higher power and better fuel consumption while controlling smoke and particulate
formation.
In most recreational and light duty commercial marine applications, the exhaust system and
turbocharger are generally water-jacketed to keep surface temperatures low. In addition, raw water
is actually mixed with the exhaust for cooling and tuning reasons. Because the exhaust is dumped
directly into the surrounding water, the more gradual cooling from mixing water with the exhaust
prevents a large pressure spike which could affect the exhaust tuning. The water jacketing causes
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Chapter 3: Technological Feasibility
some of the reclaimed energy in the turbocharger to be lost to the cooling water. This energy loss
is not large and could be reduced further by insulating the turbine from the water jacket. For larger
marine engines, insulation rather than water j acketing is generally used to keep surface temperatures
down. For these engines, dry exhaust is directly emitted into the atmosphere.
Aftercooling is often used to reduce NOx by reducing the temperature of the charge air after it
has been heated during compression. Reducing the charge air temperature directly reduces the peak
cylinder temperature during combustion which is where NOx is formed. This technology was
initially developed to improve the specific power output of an engine by increasing the density of
air entering the combustion chamber. Water-to-air and air-to-air aftercooling are well established
for land-based engine applications. For engines in marine vessels, there are two different types of
aftercooling strategies used: jacket-water, and raw-water aftercooling. Because of the access that
marine engines have to a large cooling medium (i.e. oceans and lakes), EPA anticipates aftercooling
will play an important role in gaining significant NOx reductions from marine diesel engines.
1. Jacket-water aftercooling
Marine engines use jacket water systems to pull heat from the engine coolant. Raw water is
pumped into a heat exchanger which is used to cool the engine coolant. For most recreational and
light commercial applications, the raw water is then used to cool the exhaust. If jacket-water
aftercooling is applied, the coolant coming from the heat exchanger passes through the aftercooler
before entering the engine. Through the use of jacket-water aftercooling, boost air may be cooled
to approximately 95-105°C. Another 40 to 50°C reduction in boost air temperature can be gained
by using a completely separate cooling circuit for the aftercooler.
The heat exchanger is designed to resist the difficulties associated with operating in a sea-water
environment. Water is pumped through the heat exchanger at a high velocity to help prevent
barnacle growth and to keep the passages clean. In addition, copper is a poison to barnacles and the
heat exchangers are generally made of a copper-nickel alloy. To prevent sea water from causing the
metal in the heat exchanger to decay due to electrolysis, zinc anodes are used.
In commercial applications where the water temperature is expected to be near freezing or very
dirty, keelcooling may be used. In a keelcooled system, the engine coolant is passed through many
long tubes along the bottom of the boat which act as a heat exchanger. Therefore, no ambient water
is brought into the vessel or cooling system. This avoids problems that could be associated with
contaminants such as mud, chemicals, or ice. In displacement hull vessels keelcooling can be as
effective as a standard heat exchanger and is often used on commercial vessels. One disadvantage
of keel cooling is that it is a more complex and costly system than a standard shell and tube heat
exchanger. Also, keelcooling is less effective on a planing vessel, and is not often used for
recreational vessels.
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Regulatory Impact Analysis
2. Raw-water aftercooling
Raw-water aftercooling means that outside water is pumped through the aftercooler rather than
engine coolant. Depending on the temperature of the water and the size of the aftercooler, raw-water
aftercooling can be used to cool the boost air to approximately 45-55°C. Because of the cooler
intake air temperatures associated with this technology, it can be used to achieve lower NOx levels
from a marine engine. The same strategies used to protect the jacket water heat exchanger from the
corrosive effects of sea water can also be used to protect a raw-water aftercooler. Currently, this
aftercooling strategy is only used in recreational and light commercial applications. While
introducing raw-water aftercooling may require additional maintenance (replacing anodes), the
benefits of improved fuel efficiency, greater engine durability, and better control of NOx emissions
make a compelling case for its widespread use in the long term.
D. Electronic Control
Various electronic control systems are in use or under development for nonroad, locomotive,
highway, and marine diesel engines. Use of electronic controls enables designers to implement
much more precise control of the fuel injection system and is necessary for advanced concepts such
as rate shaping. Through this precise control, trade-offs between various control strategies can be
minimized. In addition, electronic controls can be used to sense ambient conditions and engine
operation to maximize performance and minimize emissions over a wide range of conditions such
as transient operation of the engine. Electronic control is already used in limited marine applications
and has shown its ability to endure the marine environment. These same controls used today could
be used to optimize for emissions as well as performance.
E. Exhaust Gas Recirculation
Exhaust gas recirculation (EGR) is the most recent development in diesel engine control
technology for obtaining significant NOx reductions. EGR reduces peak combustion chamber
temperatures by slowing reaction rates and absorbing some of the heat generated from combustion.
While NOx emissions are reduced, PM and fuel consumption can be increased, especially at high
loads, because of the reduced oxygen available during combustion.21'22 One method of minimizing
PM increases is to reduce the flow of recirculated gases during high load operation, which would
also prevent a loss in total power output from the engine. Recent experimental work showed NOx
reductions of about 50 percent, with little impact on PM emissions, using just six percent EGR in
conjunction with a strategy of multiple injections.23
1. EGR cooling
There are several methods of controlling any increase in PM emissions attributed to EGR. One
method is to cool the exhaust gas recirculated to the intake manifold. By cooling the recirculated
gas, it takes up less volume allowing more room for fresh intake air. With EGR cooling, a much
higher amount of exhaust gas can be added to the intake charge. At light loads, there can be a small
NOx penalty due to increased ignition delay, but at high loads, some additional NOx reduction may
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Chapter 3: Technological Feasibility
result from EGR cooling.24 Another method to offset the negative impacts of EGR on PM is through
the use of high intake air boost pressures. By turbocharging the intake air, exhaust gas can be added
to the charge without reducing the supply of fresh air into the cylinder.25
2. Soot removal
Another challenge facing manufacturers is the potential negative effects of soot from the
recirculated exhaust being routed into the intake stream. Soot may form deposits in the intake
system, which could cause wear on the turbocharger or decrease the efficiency of the aftercooler.
As the amount of soot in the cylinder increases, so does the amount of soot that works its way past
the piston rings into the lubricating oil, which can lead to increased engine wear. One thing that has
been developed to reduce soot in the recirculated exhaust gas is a low-voltage soot removal device.26
Engine wear was shown to be greatly reduced as a result of this device. Another strategy is to
recirculate the exhaust gas after it has passed through a particulate trap or filter. Demonstrations
have shown that some prototype traps can remove more than 90 percent of particulate matter.27
One study discusses a technology package designed to solve the problems of minimizing the
amount of intake charge displaced by exhaust gas and of fouling of the turbocharger and
aftercooler.28 This technology package uses a variable geometry turbocharger, an EGR control valve,
and a venturi mixer to introduce the recirculated gas into the inlet stream after the intake air is
charged and cooled. The variable geometry turbocharger is used to build up pressure in the exhaust
stream. Once the pressure is high enough, the EGR control valve is opened and the recirculated gas
is mixed into the high pressure inlet stream in a venturi mixer. Although the recirculated gas is
cooled, this cooling is minimal to prevent both fouling in the cooler (due to condensation) and a
large pressure drop across the cooler.
Several bypass filtration designs exist to filter smaller particles out of engine oil.29 With bypass
filtration, a portion of the oil is run through a secondary unit which results in well filtered oil. This
type of filtration system could be used to minimize negative effects of soot in the oil that are
associated with high levels of EGR. At least one design claims efficiencies of up to 99 percent in
capturing 1-micron particles. Another design is capable of removing water as well as particles less
than 1 micron in size. To accelerate vaporization of impurities and to maintain oil viscosity, a heated
diffuser plate is used in a third design.
F. Exhaust Aftertreatment Devices
Researchers in industry and academia have explored various technologies for treating engine-out
exhaust emissions. In general, EPA does not expect that marine engine manufacturers will need to
utilize exhaust aftertreatment to meet the proposed standards; however, further work on these
technologies may lead to development of an approach that provides effective control at a lower cost
than today's anticipate technologies. One technical difficulty that would have to be investigated is
the concern of catalyst poisoning in a salt-water environment.
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Regulatory Impact Analysis
1. Oxidation catalysts
The flow-through oxidation catalyst provides relatively moderate PM reductions by oxidizing
both gaseous hydrocarbons and the portion of PM known as the soluble organic fraction (SOF). The
SOF consists of hydrocarbons adsorbed to the carbonaceous solid particles and may also include
hydrocarbons that have condensed into droplets of liquid.34 The carbon portion of the PM remains
largely unaffected by the catalyst. Although recent combustion chamber modifications have reduced
SOF emissions, the SOF still comprises between 30 and 60 percent of the total mass of PM.
Catalyst efficiency for SOF varies with exhaust temperature, ranging from about 50 percent at 150°C
to more than 90 percent above 350°C.30
Another challenge facing catalyst manufacturers is the formation of sulfates in the exhaust. This
is especially true for marine engines which tend to use fuels with higher sulfur levels than land-based
engines. At higher exhaust temperatures, catalysts have a greater tendency to oxidize sulfur dioxide
to form sulfates, which contribute to total PM emissions. For highway applications, this is helped
by the introduction of low-sulfur fuel. In addition, catalyst manufacturers have been successful in
developing catalyst formulations that minimize sulfate formation.31 Catalyst manufacturers have also
adjusted the placement of the catalyst to a position where the needed SOF reduction is achieved, but
sulfate formation is minimized.32 Marine fuel with sulfur concentrations higher than 0.05 weight
percent may prevent the use of more active oxidation catalysts with higher conversion efficiencies.
2. Particulate traps
Use of a parti culate trap is a very effective way of reducing parti culate emissions, including the
carbon portion. Particulate traps have been extensively developed for highway applications, though
very few engines have been sold equipped with traps, primarily because of the complexity of the
systems needed to remove the collected particulate matter. Continued efforts in this area may lead
to simpler, more durable designs that control emissions cost-effectively. Research in this area is
focused on developing new filter materials and regeneration methods. Some designs rely on an
additive acting as a catalyst to promote spontaneous oxidation for regeneration, while other designs
aim to improve an active regeneration strategy with microwave or other burner technology.
3. Selective Catalytic Reduction
Selective catalytic reduction (SCR) is one of the most effective, but also most complex and
expensive, means of reducing NOx from large diesel engines. Emission reductions in excess of 90
percent can be achieved using SCR.33 In SCR systems, a reducing agent, such as ammonia, is
injected into the exhaust and both are channeled through a catalyst where NOx emissions are
reduced. These systems are being successfully used for large stationary source applications which
operate under constant, high load conditions.
A number of disadvantages are apparent for the use of current technology SCR systems on
ships. The SCR system is effective only over a narrow range of exhaust temperatures. The
effectiveness of the system is decreased at reduced temperatures exhibited during engine operation
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Chapter 3: Technological Feasibility
at partial loads. Also, excess ammonia in the exhaust can occur during transient operation, where
control of optimum ammonia injection is difficult. However, because marine engines (especially
larger engines) operate under fairly steady-state conditions, this "ammonia slip" would be less of a
problem.
G. Water Emulsification
Water emulsification of the fuel is a technique which also lowers maximum combustion
temperature without an increase in fuel consumption. Water has a high heat capacity, which allows
it to absorb enough of the energy in the cylinder to reduce peak combustion temperatures. There are
at least two ways to accomplish the emulsification during combustion: in the combustion chamber
or in the fuel tank. Testing on a diesel engine has shown a 40 percent reduction in NOx with a
water-fuel ratio of 0.5 with only a slight increase in smoke.34 Water dilution does have significant
challenges. Combining water and fuel for the first time in the chamber requires significant changes
to the cylinder head to add an injector. Using a single injector with stratified water and fuel adds
complexity to the injection system. Combining water with fuel in the tank may introduce
combustion problems due to unstable emulsion. Also, this technique requires a significantly
redesigned fuel handling system to overcome the potential risk of corrosion and to maintain power
output. However, these problems may be overcome in the future as the strategy is refined. In any
event, extra liquid storage availability is necessary to retain similar range.
VI. Emission Measurement
In any program designed to achieve emissions reductions from internal combustion engines, the
test procedures that are used to determine emissions levels are as important as the emissions
standards that are implemented. Five duty cycles were investigated for use in this rule: three
designed for propulsion marine diesel engines, one used for land-based nonroad diesel engines, and
one intended for constant-speed auxiliary diesel engines. These cycles are designated by the
International Standards Organization (ISO) as E2, E3, E5, Cl, andD2, respectively.35 This section
discusses the duty cycles proposed for this rule as well as other testing issues specific to marine
diesel engines.
A. Certification Duty Cycles
The E3 duty cycle is proposed to be used for measuring emissions from propulsion marine
diesel engines operating on a propeller curve. Both the E3 and the E5 are designed to represent
marine diesel engines, and both cycles focus on operational modes which lie on a propeller curve.
However, the E3 is intended to represent heavy-duty diesel marine engine operation while the E5
is intended to represent diesel marine engine operation on vessels less than 24 meters in length. In
addition, the E3 operates at a higher average power than the E5. These two facts imply that the E3
is probably more representative for commercial while the E5 is probably more representative for
recreational marine diesel engines. Since most of the combined HC and NOx emissions from marine
diesel emissions come from commercial applications, the use the E3 cycle for all marine propulsion
diesel engines operating on a propeller curve is acceptable. Using single cycle to represent all
41
-------
Regulatory Impact Analysis
propeller-curve marine diesel engines should reduce certification burdens for marine engines that
are used in both vessels under and over 24 meters in length. More detail on this issue may be found
in the docket.36
For auxiliary marine diesel engines, ISO provides the Cl and D2 duty cycles. Auxiliary marine
engines would include any engines used on a marine vessel which are not primarily used for
propulsion. The Cl duty cycle was developed for nonroad diesel engines and applies to variable-
speed engines while the D2 applies to constant speed engines. The D2 duty cycle is a five-mode
cycle at a constant speed which is intended for generator sets with an intermittent load and is
currently allowed as an option for the certification of land-based constant speed engines.
Many larger propulsion marine engines do not operate on a propeller curve. These engines run
at a constant speed and use a variable pitched propeller to control vessel speed. EPA proposes that
the E2 constant speed propulsion marine duty cycle be used for these engines. Figure 3-1 presents
the five duty cycles discussed above.
There is another class of propulsion engines that run at variable speed and use a variable pitched
propeller. These engines are designed to operate near the power curve for the engine in order to
maximize fuel efficiency. In general, these engines will operate at a constant speed except when
maneuvering in port. Because of the expense of the system, variable speed engines are rarely used
with variable pitched propellers. ISO does not have a test duty cycle specifically designed for these
engines. However, because most of there operation is at constant speed, EPA is proposing that these
engines certify to the E2 duty cycle. It should be noted that the speed setting for testing should
coincide with the speed setting at which the engine would spend most of its time in use.
42
-------
100%
g-
o
80%
•o 60%
N
"ro
E 40%
o
20%
0%
0
g. 80%
o
•a 60%
N
40%
20%
0%
Figure 3-1: CI Marine Test Duty Cycles Plotted Under the Full Load Torque Curve
(percentages are modal weightings used to calculate a composite emissions level)
ISO E3 Commercial Marine
Idle
Intermediate
Engine Speed
Rated
ISO E5 Recreational Marine
32%»
30°/
Idle
Intermediate
Engine Speed
Rated
ISO C1 Land-Based CI Nonroad
1UU7o
F
o
T3
0
N
"ro
80%
60%
40%
20%
0%
15°/
Idle
Intermediate
Engine Speed
Rated
ISO E2 Variable Propeller
80%
3 60%
N
"ro
E 40%
20%
0%
Rated
Engine Speed
ISO D2 Constant Speed
100%
80%
-o 60%
0
N
"ro
E 40%
o
z
20%
0%
Rated
Engine Speed
-------
Regulatory Impact Analysis
B. Relative Stringency of Duty Cycles
In general, emissions levels are sensitive to the duty cycle used to generate them. For instance,
if emissions from a given engine were lower on the marine cycle than on the land-based nonroad
duty cycle, it would suggest that lower standards would be necessary to ensure the same level of
control from marine engines as will be achieved from nonroad land-based diesel engines. However,
according to EPA's analysis in the case of Cl versus E3 and the locomotive line-haul cycle versus
E2, emissions tend to be roughly equivalent. This analysis is described below.
1. Category 1 marine vs. land-based test procedure
Test data on five uncontrolled Category 1 marine diesel engines37'38 show that HC+NOx
emissions are approximately the same when measured on the Cl or E3 duty cycle. This would
suggest that emission levels determined using the Cl cycle would be roughly equivalent to those
determined using the E3 cycle. Although there is more variation between the E3 and the D2 results,
it seems reasonable to consider the same standard levels based on both duty cycles. However, data
on the same engines show that HC+NOx emissions measured on the E5 duty cycle is somewhat
higher. Table 3-1 presents HC+NOx results for these five engines based on the E3, Cl, D2, and E5
cycles. For controlled marine diesel engines, EPA anticipates that it will be somewhat easier to
demonstrate compliance on the E3 cycle than the Cl cycle since the E3 only has half as many test
modes and does not include the peak torque mode that drives many nonroad diesel engine emission
control designs.
Table 3-1
HC+NOx Results by Duty Cycle for Five Uncontrolled Marine Diesel Engines
Duty Cycle
E3 (g/kW-hr)
Cl (g/kW-hr)
Cl(% difference)
D2 (g/kW-hr)
D2 ( % difference)
E5 (g/kW-hr)
E5 (% difference)
Rated Power (kW)
20
6.9
6.7
-2%
8.3
21%
9.6
39%
265
9.8
9.9
2%
8.7
-11%
11.4
17%
336
7.1
6.6
-8%
6.9
-3%
8.1
15%
447
10.2
9.5
-7%
8.2
-20%
12.6
23%
895
10.0
10.1
1%
8.1
-19%
10.8
9%
44
-------
Chapter 3: Technological Feasibility
2. Category 2 marine vs. locomotive line-haul
The proposed standards for Category 2 marine diesel engines are based on the line-haul
standards for locomotive engines. Although locomotive engines must certify to two duty cycles with
separate standards, EPA focused on the line-haul standard as being more applicable to marine
engines. This is because the line-haul duty cycle has a high average power similar to the commercial
marine diesel duty cycles. Another similarity between the locomotive and marine duty cycles is that
they are based on a path of operation under the torque curve rather than over the whole torque curve.
Locomotive engines run at eight distinct operating points or "notches" in real world use while marine
engines either operate over a propeller curve or at constant speed.
To compare the relative stringency of the marine E2 and E3 and the locomotive line-haul duty
cycles, EPA looked at baseline emission data based on these cycles. Data on thirteen locomotive
engines39 and twenty-one marine engines40'41'42 are presented in Figure 3-2. This data clearly shows
that combined HC and NOx baseline emissions from engines tested on the three duty cycles are at
about the same levels.
Figure 3-2: Comparison of HC+NOx Emissions for Marine and Locomotive Engines
25
20
_c
:> 1*S
> I0
_*:
[o>
X
0
+ m
o 10
I
o
(
4
*fe
*^ * *
^b sj.- NIX
xix 2fc^ %£
• •_\-_~r-^vC Six .xgSc
M -^^Mx^Sfc ^XlX
* ^ ^m *
•
• •
i i i i i i i i i i i i
) 1000 2000 3000 4000 5000 60C
500 1500 2500 3500 4500 5500
Rated Power [kW]
* Marine Propeller Law E3 Marine Constant Speed E2 >K Locomotive Line-Haul
0
45
-------
Regulatory Impact Analysis
C. Emission Control of Typical In-Use Operation
EPA is concerned that if a marine engine is designed for low emissions on average over a low
number of discrete test points, it may not necessarily operate with low emissions in-use. This is due
to a range of speed and load combinations that can occur on a vessel which do not necessarily lie on
the test duty cycles. For instance, the test modes for the E3 cycle lie on an average propeller curve.
However, a propulsion marine engine may never be fitted with an "average propeller." In addition,
a light vessel with a planing hull may operate at lower torques than average while the same engine
operated on a heavy vessel with a deep displacement hull may operate at higher torques than average.
In addition, a planing hull vessel can operate at high torques at low speed prior to planing.
It is EPA's intent that an engine would operate clean under all in-use speed and load
combinations that can occur on a vessel rather than just at the discrete test modes in the proposed
duty cycles. To ensure this, EPA is proposing to establish requirements extending to typical in-use
operation. For propulsion marine engines certified to the E3 duty cycle, EPA proposes to apply a
"not to exceed" (NTE) zone based on the maximum power curve of the engine. Under this
provision, the manufacturers would be required to design their engines to comply to a not to exceed
limit, tied to the standard, for all of the regulated pollutants within the NTE zone. In cases where
the engine is included in averaging, banking, or trading of credits, the not to exceed limits would be
tied to the family emission limits. EPA would reserve the right to test an engine in a lab or installed
on a vessel to confirm compliance to this requirement.
When testing the engine within the NTE zone, the engine could be operated in any manner that
could reasonably be expected to be seen by that engine in use. Examples of transience that would
be included are bringing a vessel to plane or changing engine speeds. Because most of the time
marine engines operate under fairly steady speeds and loads, EPA believes that it is reasonable to
average out any emissions spikes due transience over a short period of time. To ensure that a short
transient does not unfairly give high results, EPA proposes that the emissions sampling must be at
least over a 30 second time period. This 30 second sampling period should be long enough to allow
an emissions spike to be averaged out while still retaining a short enough period to look at a specific
type of operation. Regardless of the shape of the NTE zone, an acceleration associated with bringing
a vessel to plane would be considered by EPA to be acceptable to be included for NTE type testing.
Any transient operation tested under the NTE provisions would have to be representative of what
an application using that engine could see in-use.
For engines certified on the E3 cycle, the NTE zone is proposed to be defined by the maximum
power curve, actual propeller curves, and speed and load limits. The E3 duty cycle itself is based
on a cubic relationship between speed and power which intersects the rated power point of the
engine. For the NTE zone, the upper boundary would be based on a speed squared propeller curve
passing through the 115 percent load point at rated speed and the lower boundary would be based
on a speed to the fourth propeller curve passing through the 85 percent load point at rated speed.
These propeller curves are believed to represent the full range of propeller curves seen in use.43 To
prevent imposing an unrealistic cap on a brake-specific basis, EPA proposes to limit this region to
power at or above 25 percent of rated power and speeds at or above 63 percent of rated speed. These
46
-------
Chapter 3: Technological Feasibility
limits are consistent with mode 4 in the E3 duty cycle. The proposed NTE zone is illustrated in
Figure 3-3. For engines operating in applications in which the in-use operation differs significantly
from the NTE zone in Figure 3-3, manufacturers would be able to petition for adjustments to the
NTE zone for a given engine design.
47
-------
o
Q.
(
120% -
110% -
100% -
90% -
80% -
70% -
60% -
50% -
40% -
30% -
20% -
10% -
0%
Figure 3-3: Illustration of "Not to Exceed" Zone
o
115% Load Point
E3 Test Points
Lug Curve
Speed Prop Curve
25% Load Line
50% 55% 60% 65% 70% 75% 80% 85%
Normalized Speed
90%
95%
100%
105%
-------
Chapter 3: Technological Feasibility
For constant speed propulsion engines certified to the E2 duty cycle, EPA proposes a similar
approach to ensuring that emissions measured on the duty cycle are representative of emissions
generated in-use. Because these engines operate at a constant speed, the NTE zone is easier to define
than for the E3 duty cycle. The not to exceed limits would apply to the speed that the engine is
designed to operate at for all loads greater than or equal to 25 percent of maximum load at that speed.
Below 25 percent load, EPA is not proposing a NTE cap because brake-specific emissions become
large at low loads due to a small power level in the denominator which would make it technically
difficult to adhere to a single cap throughout the zone. In addition, these engines generally do not
spend much time operating at low loads.
Ambient air conditions would likely have a significant effect on emissions from marine engines
in use. Such ambient air conditions include temperature and humidity. To ensure real world
emissions control, the NTE zone testing should include a wide range of ambient air conditions
representative of real world conditions. EPA believes that the appropriate ranges should be 13-3 5 °C
(55-95°F) for air temperature and 7.1-10.7 grams water per kilogram of dry air (50-75 grains/pound
of dry air) for air humidity. The air temperature and humidity ranges are consistent with those
developed for NTE testing of on-highway heavy-duty diesel engines. The air temperature ranges
were based on temperatures seen during ozone exceedences.44 For NTE testing in which the air
temperature or humidity is outside of the range, the emissions shall be corrected back to the air
temperature or humidity range. These corrections shall be consistent with the equations in 40 CFR
Part 89 Subpart E. These equations correct to 25°C and 10.7 grams per kilogram of dry air.
However, corrections associated with the NTE testing shall be to the nearest outside edge of the
specified ranges. For instance, if the temperature were higher than 35°C, a temperature correction
factor would be applied to the emissions results to determine what the emissions would have been
at35°C.
Ambient water temperature also may affect emissions due to its impact on engine and charge
air cooling. For this reason, NTE testing would include a range of ambient water temperatures from
5-32°C (41-90°F). The water temperature range is based on temperatures that marine engines
experience in the U. S. in use. It is EPA's understanding that marine engine manufacturers currently
design their cooling systems for the worst case condition of 32°C water temperatures. Although
marine engines experience water temperatures near freezing, EPA does not believe that additional
emission control will be gained by lowering the minimum water temperature below 5°C. At this
time, EPA is not aware of an established correction factor for ambient water temperature. For this
reason NTE zone testing must be within the specified ambient water temperature range.
EPA is aware that many marine engines are designed for operation in a given climate. For
instance, an engine in a fishing vessel designed to operate in Alaska would not need to be designed
for 32°C water temperatures. For situations such as this, manufacturers would be able petition for
the appropriate temperature ranges associated with the NTE zone for a specific engine design. In
addition, EPA understands that there are times when emission control needs to be compromised for
startability or safety. Manufacturers would not be responsible for the NTE requirements under start
up conditions. In addition, manufacturers could petition to be exempt from emissions control under
49
-------
Regulatory Impact Analysis
specified extreme conditions such as engine overheating where emissions may increase under the
engine protection strategy.
EPA is proposing a single cap for the entire NTE zone. Although ideally the engine should
meet the proposed standard under any operation, EPA understands that a cap of 1.0 times the
standard would not be reasonable because there is inevitably some variation in emissions over the
range of engine operation. This is consistent with the concept of a weighted modal emission test
such as the steady-state tests proposed in this rule.
For engines certified to the E2 and E3 duty cycles, EPA believes that a not to exceed limit of
1.25 times the emissions standard (or FEL) is appropriate. EPA's decision not to apply a tighter cap
for marine engines is based on all of the emissions data in this chapter for which individual modal
results were available to EPA. Figure 3-4 presents the ratio of the modal emissions to the cycle
weighted emissions and includes both Category 1 and Category 2 marine diesel engines. This data
shows that a 1.25 limit is easily achievable for HC+NOx on constant speed engines, but may be more
challenging for variable speed engines, especially at low speeds and powers (mode 4). However,
several of the engines are below 1.25 times their cycle weighted average, and EPA believes that all
marine diesel engines can be optimized to meet a 1.25 limit, particularly as the marine engine market
shifts more towards electronically controlled engines. EPA only had modal data for CO and PM on
the E3 duty cycle. Meeting a 1.25 limit for PM appears to be equally as challenging as for HC+NOx,
but feasible as about half of the engines already meet this limit. It should be noted that the CO
emissions data presented here were well below the proposed standards, so CO should not be a
limiting factor.
This NTE zone and cap is consistent with the recent guidance for on-highway engines.45
However, on-highway engines have a much larger NTE zone which covers a full range of possible
engine operation. In addition, on-highway engines have the additional requirement of a second cap
shaped by the emission results from the 13 mode EURO test. For marine engines, the NTE zone is
much smaller and does not include peak torque or high-speed/low power operation. In addition,
marine engines characteristically see much less transient operation than heavy-duty diesel on-
highway engines in use. This reduced transient in use operation would translate into less transient
operation during NTE testing.
50
-------
Figure 3-4: Ratio of Modal Emissions to Cycle Weighted Emissions
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
HC+NOx E3 Ratio
Ratio of Modal Emissions to the Weighted Average
Mode 1
Mode 2
Mode 3
Mode 4
HC+NOx E2 Ratio
Ratio of Modal Emissions to the Weighted Average
Mode 1
Mode 2
Mode 3
Mode 4
2
1.8
1.6
£1.4
J1.2
D)
^ 1
g 0.8
=*
3 0.6
0.4
0.2
0
CO E3 Ratio
Ratio of Modal Emissions to the Weighted Average
-
I
1
I
(
I 1
—
IH-fl
—
FT
—
Mode 1 Mode 2 Mode 3
-
Mode 4
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
PM E3 Ratio
Ratio of Modal Emissions to the Weighted Average
1
Mode 1 Mode 2 Mode 3 Mode 4
-------
Regulatory Impact Analysis
EPA is interested in low emissions regardless of engine operation, but would consider dividing
the NTE zone into subzones with different caps if the single zone was shown to not be feasible. The
purpose of this is to account for differing brake-specific emissions at different operating points. In
general, marine engines have lower brake-specific emissions at high speeds and loads than at low
speeds and loads. However, EPA believes that the 1.25 limit is reasonable for the entire NTE zones
as defined above. If the NTE zone was broken into more than one subzone, it may be feasible to
have a lower cap in the high speed/high power range, and a higher cap at the low power/low speed
range. While more complicated than the single zone proposed, it would nevertheless appear to be
feasible based on the data in Figure 3-4. If a zone was divided into subzones, it would not be
reasonable to allow too much variation in the caps since it is important that the engines cannot be
designed only to operate at low emissions at certain modes. This is especially true for engines used
in applications whose operation is significantly different from the E3 duty cycle. In addition, having
different subzones with different caps would increase the complexity of the NTE provision,
especially for transient operation that reaches into more than one subzone.
The use of electronic controls should give marine engine manufactures more flexibility in how
they meet the proposed cap under all operation than they would have with mechanically controlled
engines with fixed injection timing. EPA is concerned, however, that electronic controls (or any
other Auxiliary Emission Control Devices) not be used in such a way as to result in higher emissions
from marine engines in-use than would be seen during testing. EPA believes that the best way of
ensuring this is the use of the NTE provisions. In addition, however, EPA believes that it is
appropriate to require that the manufacturers provide information such as message or parameter
identification, scaling, limit, offset, and transfer function information required to interpret all
messages and parameters broadcast on an engine's controller area network. In addition, requiring
that electronically controlled engines broadcast their engine speeds and loads on the controller area
networks would help facilitate in-use testing.
EPA recognizes the difficulties of complying to a single cap over an NTE zone with a
mechanical engine due to the restriction of a fixed injection timing. Nevertheless, the requirement
for effective in-use emission performance over the broad range of in-use operation should not be
restricted to electronically controlled engines. Even with mechanical controls, EPA believes that it
is feasible for marine engines to meet the proposed requirements through optimization of the engine
calibration. However, EPA is concerned that this would cause an unnecessary increase in emissions
at higher speeds and loads where marine engines spend most of their time. Therefore, EPA would
consider options for mechanical engines such as subzones, smaller zone, or phase in of requirements
if there were no significant loss to the environment or market advantage to mechanical engines
created.
EPA is not proposing any NTE provisions for auxiliary marine engines certified using the D2
and Cl duty cycles. At this time, EPA does not have enough information on the operation and
design of these engines. However, EPA will investigate typical emissions from auxiliary marine
engines off of the D2 and Cl duty cycles and act appropriately. Finally, because the impact of NTE
is not fully understood for very large propulsion engines and to be consistent with the EVIO
52
-------
Chapter 3: Technological Feasibility
requirements, EPA does not believe that it is appropriate to extend the NTE concept to Category 3
engines at the present time.
D. Emissions Sampling
Aside from the duty cycle, the test procedures for CI marine engines are proposed to be similar
to those for land-based nonroad diesel engines. However, there are a few other aspects of marine
diesel engine testing that need to be considered. Many recreational, auxiliary, and light-commercial
marine engines mix cooling water into the exhaust. This exhaust cooling is generally done to keep
surface temperatures low for safety reasons and to tune the exhaust for performance and noise. Since
the exhaust must be dry for dilute emission sampling, the cooling water must be routed away from
the exhaust in a test engine.
Even though many marine engines exhaust their emissions directly into the water, EPA is
proposing to base its test procedures and associated standards on the emissions levels in the "dry"
exhaust. Relatively little is known about water scrubbing of emissions. EPA must therefore
consider all pollutants out of the engine to be a risk to public health. Additionally, EPA is not aware
of a repeatable laboratory test procedure for measuring "wet" emissions. This sort of testing would
be nearly impossible from a vessel in-use. Finally, a large share of the emissions from this category
come from large engines which emit their exhaust directly to the atmosphere.
The established method for sampling transient emissions is through the use of full dilution
sampling. However, for larger engines the exhaust flows become so large that conventional dilute
testing would require a very large and costly dilution tunnel. One option for these engines is to use
a partial dilute sampling method in which only a portion of the exhaust is sampled. It is important
that the partial sample be representative of the total exhaust flow. The total flow of exhaust can be
determined by measuring fuel flow and balancing the carbon atoms in and out of the engine. For
guidance on shipboard testing, EVIO NOx Technical Code specifies analytical instruments, test
procedures, and data reduction techniques for performing test-bed and in-use emission
measurements.46 Partial dilution sampling methods can provide accurate steady-state measurements
and show great promise for measuring transient emissions in the near future. EPA intends to pursue
development of this method and put it in place prior to the date that the standards in today's proposal
become enforceable.
Because marine engines often become an integral part of a vessel and cannot easily be
removed, EPA proposes the option for in-use testing to be performed on the vessel. There are
several portable sampling systems on the market that, if used carefully, can give fairly accurate
results. For Category 3 engines, and some Category 2 engines, it may not be feasible to test the
engines on a dynamometer. When this is the case, it may be more appropriate to test the engine
aboard the vessel. For these vessels, there should be enough space to bring an electro-chemical
sampler aboard similar to those used for stationary source testing. Engine speed can be monitored
directly, but load may have to be determined indirectly. For constant speed engines, it should be
relatively easy to set the engine to the points specified in the duty cycles.
53
-------
Regulatory Impact Analysis
VII. Baseline Technology Mix
A. Category 1 Marine Diesel Engines
EPA developed estimates of the current mix of technology for Category 1 marine diesel engines
based on data from the 1997 Power Systems Research (PSR) OE Link database and from
conversations with marine manufacturers. Based on this information, EPA estimates that 70 percent
of new marine engines are turbocharged, and 70 percent of these turbocharged engines use
aftercooling. The majority of these engines are four-strokes, but about 20 percent of Category 1
engines are two-strokes. Although indirect injection (TDI) is mostly used with smaller diesels,
engines with IDI account for about 10 percent of total CI sales for the past five years. Electronic
controls have only recently been introduced into the marine market place; however, EPA anticipates
that their use will increase as customers realize the performance benefits associated with electronic
controls and as the natural migration of technology from on-highway to nonroad to marine occurs.
Table 3-2 provides more detail on the baseline technology mix.
Table 3-2
Baseline Technology Mix of Category 1 Marine Diesel Engines
Technology
natural aspiration
turbocharger
no aftercooler
jacket- water aftercooler
raw- water aftercooler
direct injection
indirect injection
mechanical control
electronic control
Auxiliary
47%
53%
70%
21%
9%
78%
22%
97%
3%
Recreational
29%
71%
48%
46%
6%
90%
10%
99%
1%
Commercial
31%
69%
53%
41%
6%
96%
4%
100%
0%
Aggregate
30%
70%
50%
44%
6%
91%
9%
99%
1%
With regard to baseline emissions, data from eight high-speed marine diesel engines '• are
presented in Table 3-3 and compared to the proposed standards. For the seven propulsion marine
engines, the results are based on the E3 test cycle; the D2 test cycle was used for the auxiliary marine
engine. PM emissions were not sampled from all of the engines. This data shows to what extent
emissions need to be reduced from today's Category 1 marine diesel engines to meet the proposed
standards. On average, EPA is requiring significant reductions in HC+NOx and PM; however, the
proposed CO standards will just act as a cap.
54
-------
Chapter 3: Technological Feasibility
Table 3-3
Emissions Data from Baseline Category 1 Marine Diesel Engines
Rated
Power
(kW)
20
71*
237
262
265
336
447
895
Technology Mix
naturally aspirated
indirect injection
naturally aspirated
turbochraged
turbocharged
raw- water aftercooled
turbocharged
jacket- water aftercooled
turbocharged
turbocharged
jacket- water aftercooled
turbocharged
jacket- water aftercooled
Emissions Data g/kW-hr
HC
0.27
3.45
0.03
0.37
0.35
0.09
0.52
0.27
NOx
6.6
8.3
9.1
7.8
9.4
7.0
9.7
9.7
CO
2.8
11.5
1.4
0.7
0.6
1.6
1.7
1.3
PM
0.99
1.17
—
—
—
0.17
0.17
—
Proposed Standards
HC+NOx
—
7.8/4.0
7.8/4.0
7.8/5.0
CO
—
5.0
3.5
2.0
PM
—
0.4
0.2
0.27
* Because this is an auxiliary marine engine, this data is based on the D2 test cycle.
B. Category 2 Marine Diesel Engines
Category 2 marine engines are essentially marinized locomotive two and four-stroke engines.
Two-stroke engines currently make up the vast majority of the fleet; however, four-stroke engines
are expected to gain market share as locomotives go to four-stroke to meet the recently finalized
standards for locomotive engines. Like locomotive engines, almost all Category 2 marine diesel
engines use turbochargers to increase their power to weight ratios. About 90 percent of Category
2 marine diesel engines are turbocharged and jacket water aftercooled. A small fraction of these
aftercoolers are on a separate circuit from the engine cooling system. Electronic controls have not
really made any inroads into this class of engines.
Baseline emission data is drawn from five Category 2 marine diesel engine pairs that were
emission tested for the U.S. Coast Guard.50 The E3 weighted emission results from these engines
are presented in Table 3-4. Of these five engine pairs, two have emissions levels below the Tier 0
locomotive engine standards and a third has emission levels below the Tier 1 locomotive engine
emission standard. These marine engines probably have somewhat lower baseline emissions than
locomotive engines because locomotive engines are severely constrained in their heat rejection
55
-------
Regulatory Impact Analysis
capabilities while marine engines have the advantage of being able use to the oceans, rivers, and
lakes as a large heat sink. Additional testing of Category 2 engines by Lloyd's Register confirms that
Category 2 marine engines have lower emissions than baseline locomotive engines.51'52 This data was
included in Figure 3-2. The Lloyd's data is particularly interesting because it measures emissions
from commercial vessels in-use.
Table 3-4
Emissions Data from Baseline Category 2 Marine Diesel Engines
Rated
Power
(kW)
1460*
1710*
1900*
2190*
2380*
Technology Mix
turbocharged
turbocharged
turbocharged, aftercooled
turbocharged
turbocharged, two-stroke
opposed piston
Emissions g/kW-hr
HC
0.50
0.03
0.03
0.00
0.11
NOx
16.5
13.1
16.4
11.3
9.5
CO
1.1
1.4
4.1
4.9
0.9
PM
0.52
0.17
0.27
0.32
—
Proposed Standards
HC+NOx
7.8/5.0
CO
2.0
PM
0.27
The emissions results reported here are averages of engine pairs.
C. Category 3 Marine Diesel Engines
Category 3 engines are significantly different from Category 1 and 2 engines in several ways
that can affect the technologies used and the baseline emissions. First these engines are intended for
a different sort of operation. Category 3 engines are typically used for propulsion on large ocean-
going commercial vessels whose service is characterized by principally by cruising operations.
Typically, the engine is coupled directly to a fixed pitch propeller, and maneuvering and reverse
propulsion is accomplished by reversing the entire engine. Category 3 engines are also used to a
lesser extent on coast-wise commercial vessels. For maneuverability in coast-wise applications,
variable pitch propellers are used to allow the engine to operate in one direction at a constant speed.
Occasionally, smaller Category 3 engines may be used for auxiliary service on ocean-going vessels.
Consequently, Category 3 engines have a characteristic operation profile that can be different
from Category 2 and Category 1 marine engines. Because of Category 3 engines' high power (3,000-
60,000 kW) and relatively continuous use, fuel is the most significant cost in a vessel's operation.
Therefore, Category 3 engines are designed and operated at the lowest brake specific fuel
consumption (BSFC) of any combustion system (as low as 0.176 kg/kW-hr).53'54 To achieve this they
are operated at maximum brake mean effective pressures (BMEP) (-1500-2200 kPa) to maximize
thermal efficiency and minimum mean piston speed (7-9 m/s) to maximize mechanical and propeller
efficiency.55 Power density (rated engine power/engine weight) is sacrificed to operate at maximum
56
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Chapter 3: Technological Feasibility
efficiency rather than maximum output. In comparison, commercial Category 2 and 1 marine
engines are often designed and operated at maximum output rather than maximum efficiency due
to economies gained in high average-trip speeds.
This operation profile has an effect on total oxides of nitrogen (NOx) and paniculate matter
(PM) emissions. For diesel engines there is an exponential relationship between NOx emissions and
peak combustion temperatures, which occur at peak combustion pressures. Keeping in mind that
BSFC is minimized if BMEP is maximized at a given speed, Category 3 engines are unfortunately
designed for and most economically operated at peak NOx formation conditions. However, these
conditions do provide for a high 95%-burn combustion temperature, which minimizes non-volatile
carbon PM emissions.56 In addition, the use of bunker fuel can result in higher NOx from Category
3 engines than for other diesel engines for two reasons: 1) nitrogen in the fuel, and 2) poor ignition
qualities leading to increased ignition delay and higher peak temperatures. Marine fuels are
discussed in more detail later in this chapter.
In general, Category 3 marine diesel engines are two-stroke cycle engines using a crosshead
piston design. This means that an additional linkage is used in the piston-crank assembly to allow
for long strokes. Charge air is generally compressed using a supercharger driven by the crankshaft
at low loads and using a turbocharger under cruising and high loads. To reduce pumping losses, the
down stroke of one piston may be used to help push intake air into the next cylinder. This charge
air is heavily cooled. Typically, large Category 3 engines will use a two stage aftercooler where the
first stage is cooled by jacket water and the second stage is cooled by raw water. Each cylinder
typically will have its own fuel inj ection pump so that each cylinder may be independently optimized
for peak performance.
Lloyd's has collected baseline emission data on many marine diesel engines.57 However, from
this data, EPA was only able to determine E2 emissions from five Category 3 engines since the
modes tested did not generally line up with the proposed test procedure. This data is presented in
Table 3-5. To generate the E2 weighted results, the raw Lloyd's data was converted to mass rates
by converting all NOx reported volume concentrations to NO2 mass concentrations and then
multiplying by exhaust flow rates calculated by carbon balance. Power was based on reported data.
Because the emission standards are based on distillate fuel and the emission data was based on
residual fuel, an adjustment of the standard to reflect residual fuel use is provided. This adjustment
of 10 percent was based on comparing Lloyd's data on distillate and residual fuel and is consistent
with the allowance provided by EVIO. EPA recognizes that the small ship population sampled is a
source of significant uncertainty; however, these results do indicate that an emissions benefit exists
for Category 3 engines.
57
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Regulatory Impact Analysis
Table 3-5: Emission Data from Baseline Category 3 Marine Diesel Engines
Rated Power
[kW]
4246
4780
4780
6545
7700
Rated Speed
[rpm]
570
520
512
510
510
Measured NOx
[g/kW-hr]
12.7
16.2
17.7
19.5
16.2
IMO NOx Standard
[g/kW-hr]
11.2
11.9
12.6
12.9
12.9
Standard Adjusted
for Bunker Fuel*
12.3
13.2
13.9
14.2
14.2
* This is a rough adjustment for comparison purposes only.
VIII. Low Emission Category 1 Marine Engines
In an effort to achieve significant and timely emission reductions from marine engines in
California, many vessels have been repowered with low-emission marine engines as part of various
demonstration programs. These repower (completed and planned) programs are the result of efforts
by local agencies such as the Santa Barbara County Air Pollution Control District and the South
Coast Air Quality Management District as well as EPA's Region 9, the Port of Los Angeles, and
others. The low-emission marine engines have been specially produced for the marine repower
programs by a number of manufacturers including Cummins, Detroit Diesel, Mercruiser, Marine
Corporation of America, and Yanmar. At this time, more than 75 low-emission high-speed marine
engines have been installed and are still operating in a wide variety of applications, and more
replacements are planned.
The emission control strategies used on these demonstration engines were targeted on achieving
low NOx. For the majority of these engines, timing was retarded at cruise and full load operating
conditions using either electronic or mechanical engine control. Another technology which achieved
low NOx emissions was indirect injection (TDI). All of the engines used raw-water aftercooling.
Vessel owners reported positively on the performance and fuel efficiency of these engines. Apart
from a problem with the calibration of electronic controls on one engine type, which has
subsequently been resolved, no significant problems have arisen as a result of the low-emission
technology.2 Table 3-6 presents emissions data from several low-emission marine engines based on
the E3 marine test cycle.58>59>60>61>62 Figure 3-5 compares the emission results from the baseline and
low-emission high-speed marine engines presented in this chapter to the proposed standards. The
emission levels of these demonstration engines compare favorably to the proposed standards.
2 The only problem that was reported was due to the calibration of the electronic controls
on one engine type. This problem has been resolved.
58
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Chapter 3: Technological Feasibility
Table 3-6: Emissions Data from Low-Emission Category 1 Marine Diesel Engines
Rated
Power
(kW)
120
132
162
164
217
232
245*
252
298*
324
575*
Technology Mix
turbocharged, raw- water
aftercooled, electronic control
turbocharged, raw- water
aftercooled, IDI
turbocharged, raw- water
aftercooled, IDI
turbocharged, raw- water
aftercooled, electronic control
turbocharged, raw- water
aftercooled, electronic control
turbocharged, raw- water
aftercooled
turbo, raw- water aftercooled,
electronic Ctrl, 2-stroke
turbocharged, raw- water
aftercooled
turbocharged, raw-water
aftercooled, electronic control
turbocharged, jacket- water
aftercooled
turbo, raw- water aftercooled,
electronic Ctrl, 2-stroke
Emissions g/kW-hr
HC
0.09
0.05
0.07
0.31
0.14
0.45
0.4
—
0.13
0.11
0.3
NOx
5.0
4.0
3.9
4.7
6.1
6.5
6.5
5.5
8.7
6.5
6.1
CO
0.96
0.13
0.17
1.6
2.1
0.99
1.0
—
0.78
2.0
3.5
PM
—
**
**
—
—
—
0.23
—
0.09
0.78
0.40
Proposed Standards
HC+NOx
7.8/4.0
7.8/4.0
7.8/5.0
CO
5.0
3.5
2.0
PM
0.3
0.2
0.27
* This data is based on Cl test cycle.
** No PM data was collected, but the manufacturer reported that there was no visible smoke.
59
-------
Regulatory Impact Analysis
Figu
14
1"
^ 10
O)
X 8
i •
O 4
X
^ 2
Z
0
1.4
1.2
F 1
<£ 0.8
.*:
S 0.6
10.4
0.2
0
8_
"^ R -
.C b
"i *\
> 5
-^ 4
— 3
0 o
o 2
1
0_
re 3-5: Diesel Marine Engine Emissions Compared to the Proposed Standards
B
*
&
1
*Q §
A A
B
,*If*
H"
#
1
£
TierS
&
1
Tier 2
|
D 100 200 300 400 500 600 700 800 900
Rated Power [kW]
R
*
P
A
~L
~ 1
£
(
C
*
P
p
B - b
C = v
J
aseline
/ith emission contro
0 100 200 300 400 500 600 700 800 900
Rated Power [kW]
R
*
X *
ss
g
XJB f;
**| ^;
SD
*J3
1
<£
1
0 100 200 300 400 500 600 700 800 900
Rated Power [kW]
— Proposed Standards
* Test Data
60
-------
Chapter 3: Technological Feasibility
IX. Anticipated Technology Mix
As discussed above, marine engines are generally derived from land-based nonroad, locomotive,
and to some extent highway engines. This allows marine engines, which generally have lower sales
volumes than other nonroad engines, to be produced more cost-effectively. Because the marine
designs are derived from land-based engines, EPA believes that many of the emission-control
technologies which are likely to be applied to nonroad engines to meet their Tier 2 and 3 emission
standards and to locomotives to meet their Tier 2 emissions standards will be applicable to marine
engines.
EPA believes that the technology listed below will be sufficient for meeting both the proposed
standards and the NTE requirements. While the transient portion of the NTE requirements may have
some effect on PM emissions, no additional hardware should be required to meet the proposed
limits. Some additional design time may be required to optimize the engine under transient
conditions. However, marine operations typically have only limited transience, and the 30 second
averaging period in the NTE testing should prevent short emissions spikes from defining maximum
emissions thereby lessening the effects of transience on NTE test results.
A. Category 1 Marine Diesel Engines
Due to the emissions standards proposed, EPA anticipates that timing retard will likely be used
in most Category 1 marine diesel applications, especially at cruising speeds, to gainNOx reductions.
The negative impacts of timing retard on HC, PM and fuel consumption can be offset with advanced
fuel injection systems with higher fuel injection pressures, optimized nozzle geometry, and
potentially through rate shaping. EPA does not expect marine engine manufacturers to convert from
direct injection to indirect injection due to these standards.
Regardless of environmental regulations, EPA believes that Category 1 engine manufacturers
would make more use of electronic engine management controls in the future to satisfy customer
demands of increased power and fuel economy. Through the use of electronic controls, additional
reductions in HC, CO, NOx, and PM can be achieved. Electronics may be used to optimize engine
calibrations under a wider range of operation. Most of the significant research and development for
the improved fuel inj ection and engine management systems should be accomplished for land-based
nonroad diesel engines which are being designed to meet Tier 2 and Tier 3 standards. Common rail
should prove to be a useful technology for meeting Tier 3, especially for smaller engines. Thus, the
challenge for this control program will be transferring land-based techniques to marine engines.
EPA projects that, under the proposed standards, all Category 1 marine diesel engines will be
turbocharged and most will be aftercooled. Aftercooling strategies will likely be mostly j acket-water
charge air cooling, and especially for Tier 3, EPA believes that separate cooling circuits for the
aftercooling will be widely used. EPA expects a significant increase in the use of raw-water charge
air cooling for engines with specific displacements under 2.5 liters per cylinder. The raw-water
aftercooling systems will have to be designed specifically for marine engines; however, since they
61
-------
Regulatory Impact Analysis
are currently in use in some applications, most of the significant developmental work for these
cooling strategies is assumed to be completed.
EPA believes that manufactures will need to use EGR to meet the Tier 3 standards. For engines
with less than 2.5 liters per cylinder, manufacturers will likely need to cool the recirculated exhaust
gas to achieve the proposed Tier 3 standards while maintaining performance and durability. Because
of the less stringent standards for the lower production volumes of engines with 2.5 liters per
cylinder or more, hot EGR should be sufficient to meet the proposed Tier 3 standards. Chapter 4
presents one possible scenario of how these technologies could be used on Category 1 marine diesel
engines to meet the proposed Tier 2 and Tier 3 standards.
By proposing standards with implementation dates that extend well into the next decade, EPA
is providing engine manufacturers with substantial lead time for developing, testing, and
implementing emission control technologies. This lead time and the coordination of standards with
those for nonroad engines allows for a comprehensive program to integrate the most effective
emission control approaches into the manufacturers' overall design goals related to performance,
durability, reliability, and fuel consumption.
B. Category 2 Marine Diesel Engines
EPA anticipates that Category 2 marine diesel engines will use the same control strategies as
Category 1 engines. As a result of the proposed Tier 2 regulations, EPA projects that the majority
of these engines will continue to be turbocharged and aftercooled. Due to changes in locomotive
engine design and the requirements of the proposed standard, EPA expects that most new Category
2 engines will be four-strokes. EPA believes that separate circuit aftercooling will most likely be
considered more attractive than single circuit aftercooling for most applications. These control
strategies are similar to those that are likely to be used on locomotive engines, except that the cooling
strategies on marine engines are expected to be more effective.
EPA believes that marine engines should be able to achieve lower emissions than locomotives
with the same emission controls due to the greater potential for cooling and because high altitude
conditions do not need to be considered in their designs. However, EPA does not consider this
advantage to be enough for Category 2 marine engines to achieve the proposed Tier 3 standards
using only the technology expected to be used on Tier 2 locomotive engines. EPA believes that the
key technologies to meeting the proposed Tier 3 levels will be common rail fuel injection systems
and exhaust gas recirculation. Chapter 4 presents one possible scenario of how the technologies
discussed in this chapter could be used on Category 2 marine diesel engines to meet the proposed
standards.
C. Category 3 Marine Diesel Engines
EPA anticipates that Category 3 engines will be able to achieve the EVIO NOx limit without
significant engine redesign. Typically, the same strategies that have been used over time to reduce
fuel consumption have generally resulted in an increase in NOx emissions. Reducing NOx with the
62
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Chapter 3: Technological Feasibility
technology used today basically means calibrating the engines with a focus on emissions as well as
fuel consumption. For instance, rate shaping may be used to inject a small amount of fuel early
followed by the remaining charge so that the majority of the fuel may undergo diffusion burning.
This would reduce NOx by reducing peak cylinder temperatures associated with the burning of fuel
that is premixed with air prior to the start of combustion. Negative impacts on fuel consumption can
also be minimized through fuel injection strategies, including increasing injection pressures and
through optimizing nozzle geometry. Wartsila NSD, a market leader in Category 3 engine
production, has demonstrated a combination of engine technologies that meets the IMO/Annex VI
emission standard. Wartsila NSD has utilized a combination of late fuel injection rate shaping,
higher cylinder compression ratio, higher fuel injection pressure and an optimized combustion
chamber to achieve a 25-3 5 percent reduction in emissions.63 Furthermore, the combination of these
technologies has no negative effect on BSFC.
X. Test Fuel Specifications
A. Category 1 and 2 Marine Diesel Engines
EPA is proposing that the recently finalized test fuel specifications for nonroad diesel engines
be applied to Category 1 and 2 marine diesel engines, with a change in the sulfur content upper limit
from 0.4 to 0.8 weight-percent (wt%). EPA believes that this will simplify development and
certification burdens for marine engines that are developed from land-based counterparts. This
proposed test fuel has a sulfur specification range of 0.03 to 0.80 wt%, which covers the range of
sulfur levels observed for most in-use fuels. Manufacturers will be able to test using any fuel within
this range for the purposes of certification. Thus, they will be able to harmonize their marine test
fuel with U.S. highway (<0.05 wt%) and nonroad (0.03 to 0.40 wt%), and European testing (0.1 to
0.2 wt%).
The intent of these test fuel specifications is to ensure that engine manufacturers design their
engines for the full range of typical fuels used by Category 1 marine engines in use. Because the
technological feasibility of the proposed standards are based on fuel with up to 0.4 wt% sulfur, any
testing done using fuel with a sulfur content above 0.4 wt% would be done with an allowance to
adjust the measured PM emissions to the level they would be if the fuel used were 0.4 wt% sulfur.
The full range of proposed test fuel specifications are presented in Table 3-7. Because testing
conducted by EPA would be limited to the test fuel specifications, it is important that the test fuel
be representative of in-use fuels.
63
-------
Regulatory Impact Analysis
Table 3-7
Proposed Category 1 and Category 2 Test Fuel Specifications
Item
Cetane
Initial Boiling Point, °C
1 0% point, °C
50% point, °C
90% point, °C
End Point, °C
Gravity, API
Total Sulfur, % mass
Aromatics, % volume
Parafins, Napthenes, Olefins
Flashpoint, °C
Viscosity @ 38 °C, centistokes
Procedure (ASTM)
D613-86
D86-90
D86-90
D86-90
D86-90
D86-90
D287-92
D 129-21 orD2622-92
D1319-89orD5186-91
D1319-89
D93-90
D445-88
Value (Type 2-D)
40-48
171-204
204-238
243-282
293-332
321-366
32-37
0.03-0.80
10 minimum
remainder
54 minimum
2.0-3.2
B. Category 3 Marine Diesel Engines
Category 3 engines typically burn residual fuel, which is the by-product of distilling crude oil
to produce lighter petroleum products such as gasoline, diesel fuel and kerosene. Residual fuel
possesses a high viscosity and density, and it typically has high ash, sulfur and nitrogen content in
comparison to marine distillate fuels. Some Category 3 engines can burn straight residual fuel, but
many burn a blend of residual and distillate, which is called intermediate fuel (IF). The two most
common IF blends burned in Category 3 engines are IF 180, which contains about 88 percent
residual fuel and IF 380 which contains about 98 percent residual fuel.64 Table 3-8 summarizes
current ASTM standards for a marine distillate oil, residual fuel, and the two most common IF
blends.
The use of residual fuel has two important consequences. First, it is more difficult to handle.
Because of it's high viscosity and high impurities, the fuel must be heated and filtered before it can
be passed to the engine. This requires additional equipment and space. Bunker fuel is kept in a
main fuel tank where it is kept heated, generally using steam coils, to just above its pour point. Prior
to use, this fuel is pumped into a settling tank, where the heavier portions settle to the bottom. Fuel
is pumped from the top of the settling tank through heaters, centrifugal separators, and filters before
entering the fuel metering pump. The centrifugal separators and filters remove water and remaining
64
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Chapter 3: Technological Feasibility
sludge from the fuel. The sludge is then routed to a sludge tank. In addition, a separate fuel tank is
usually necessary to store a lighter fuel which is used to start a cold engine.
Table 3-8
Comparison of ASTMFuel Specifications65
ISO-F symbol
Density @ 15C, max
Viscosity @ 40C
Viscosity @ 50C
Viscosity® 100C
Carbon Residue, max
Ash, max
Sulfur, max
Units
kg/m3
cSt
cSt
cSt
wt%
wt%
wt%
Distillate fuel
DMA
890
1.5-6.0
—
—
0.20*
0.01
1.5
IF 180
RMF-25
991
316
180
25
20**
0.15
5.0
IF 380
RMH-35
991
-710
380
35
22**
0.20
5.0
Residual fuel
RML-55
no max
—
—
55
no max
0.20
5.0
* Ramsbottom test
** Conradson test
Second, residual fuels can have detrimental effects on engine emissions. These fuels may
contain between 0.6-2.15 percent nitrogen by weight, and fuel-bound nitrogen is almost completely
converted to NO in diesel engines.66 It is estimated that fuel-bound nitrogen contributes 0.35 g/kW-
hr per 0.1 percent nitrogen, however test results indicate that fuel ignition quality also has a
detrimental effect on NOx emissions.67 For example ISO E3 test results on a Category 3 engine
indicate a 22 percent increase in ISO weighted NOx when residual fuel was substituted for distillate
fuel, but the fuel-bound nitrogen (0.4 percent) only accounted for 9 percent of this increase. The
remainder of the NOx increase was attributed to the fuel's poor ignition quality, which caused
excessive ignition delay at part load. At 25 percent load on residual fuel, the engine produced 50
percent more NOx than on distillate, while at full load it produced only 25 percent more than on
distillate.68
Residual fuel also has a detrimental effect on paniculate matter (PM) emissions. One Category
3-engine study69 indicated that on residual fuel, PM increased on average by a factor of 10 in
comparison to distillate. Furthermore, lab-to-lab comparisons showed ±25 percent variability in PM
results when residual fuel was tested. This unacceptable test variability has been attributed to the
effect of high sulfate concentrations on the dilute sampling method specified by the International
Standards Organization (ISO). These results have led to a remark in ISO 8178 stating that the
method has not been validated with fuel containing more than 0.8 percent sulfur by-weight. Since
65
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Regulatory Impact Analysis
even the lowest international marine distillate fuel sulfur specification is 1.5 percent, Category 3
engines operate on fuels for which no PM test method has been developed.
XL Impact on Noise, Energy, and Safety
The Clean Air Act requires EPA to consider potential impacts on noise, energy, and safety when
establishing the feasibility of emission standards for marine diesel engines. One important source
of noise in diesel combustion is the sound associated with the combustion event itself. When a
premixed charge of fuel and air ignites, the very rapid combustion leads to a sharp increase in
pressure, which is easily heard and recognized as the characteristic sound of a diesel engine. The
conditions that lead to high noise levels also cause high levels of NOx formation. Fuel injection
changes and other NOx control strategies therefore typically reduce engine noise, sometimes
dramatically.
The impact of the proposed standards on energy is measured by the effect on fuel consumption
from complying engines. Many of the marine engine manufacturers are expected to retard engine
timing which increases fuel consumption somewhat. Most of the technology changes anticipated
in response to the proposed standards, however, have the potential to reduce fuel consumption as
well as emissions. Redesigning combustion chambers, incorporating improved fuel injection
systems, and introducing electronic controls provide the engine designer with powerful tools for
improving fuel efficiency while simultaneously controlling emission formation. To the extent that
manufacturers add aftercooling to non aftercooled engines and shift from jacket-water aftercooling
to raw-water aftercooling, there will be a marked improvement in fuel-efficiency. Manufacturers
of highway diesel engines have been able to steadily improve fuel efficiency even as new emission
standards required significantly reduced emissions.
There are no apparent safety issues associated with the proposed standards. Marine engine
manufacturers will likely use only proven technology that is currently used in other engines such as
nonroad land-based diesel applications, locomotives, and diesel trucks.
66
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Chapter 3: Technological Feasibility
Chapter 3 References
1. Herzog, P., Burgler, L., Winklhofer, E., Zelenda, P., and Carterllieri, W., "NOx Reduction
Strategies for DI Diesel Engines," SAE Paper 920470, 1992.
2. Uyehara, O., "Factors that Affect NOx and Particulates in Diesel Engine Exhaust," SAE Paper
920695, 1992.
3. Durnholz, M., Eifler, G., Endres, H., "Exhaust-Gas Recirculation - A Measure to Reduce
Exhaust Emission of DI Diesel Engines," SAE Paper 920715, 1992.
4. Bazari, Z., French, B., "Performance and Emissions Trade-Offs for a HSDI Diesel Engine -
An Optimization Study," SAE Paper 930592, 1993.
5. Acurex Environmental Corporation, "Estimated Economic Impact of New Emission
Standards for Heavy-Duty On-Highway Engines," prepared for U.S. EPA, January 26, 1996.
6. See reference 4—SAE 930592
7. U.S. Environmental Protection Agency, "Emission Control Technology for Diesel Trucks:
Report to Congress," October 1993.
8. See reference 5—Acurex Environmental Corporation
9. See reference 4—SAE 930592
10. See reference 1—SAE 920470
11. See reference 4—SAE 930592
12. Pierpont, D., Reitz, R., "Effects of Injection Pressure and Nozzle Geometry on DI Diesel
Emissions and Performance," SAE Paper 950604, 1995.
13. See reference 1—SAE 920470
14. See reference 12—SAE 950604
15. Ghaffarpour, M and Baranescu, R, "NOx Reduction Using Injection Rate Shaping and
Intercooling in Diesel Engines," SAE Paper 960845, 1996
16. Piepont, D., Montgomery, D., Reitz, R., "Reducing Particulate and NOx Using Pilot
Injection," SAE Paper 950217, 1995.
17. "CAT's HEUI System: A Look at the Future?," Diesel Progress, April 1995, page 30.
18. "CAT Gears Up Next Generation Fuel Systems," Diesel Progress, August 1998, page 82.
67
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Regulatory Impact Analysis
19. Youngblood, J., "Cummins New Midrange Fuel System," presentation at SAE Diesel
Technology for the New Millennium TOPTEC, April 21, 1998.
20. "The Year in Review," Diesel Progress, June 1998, page 34.
21. See reference 1—SAE 920470
22. See reference 16—SAE 950217
23. Montgomery, D. and Reitz, R., "Six-Mode Cycle Evaluation of the Effect of EGR and
Multiple Injections on Particulate and NOx Emissions from a D.I. Diesel Engine," SAE Paper
960316, 1996
24. See endnote 1—SAE 920470
25. Uchida, N., Daisho, Y., Saito, T., Sugano, H., "Combined Effects of EGR and Supercharging
on Diesel Combustion and Emissions," SAE Paper 930601, 1993.
26. Yoshikawa, H., Umehara, T., Kurkawa, M., Sakagami, Y., Ikeda, T., "The EGR System for
Diesel Engine Using a Low Voltage Soot Removal Device," SAE Paper 930369, 1993.
27. Khalil, N., Levendis, Y., Abrams, R., "Reducing Diesel Particulate and NOx Emissions via
Filtration and Particle-Free Exhaust Gas Recirculation," SAE Paper 950736, 1995.
28. Baert, R., Beckman, D., Verbeek, R., "New EGR Technology Retains HD Diesel Economy
with 21st Century Emissions," SAE Paper 960848, 1996.
29. Fleet Owner, "Hardware Report: What's new in... Bypass Filtration," magazine article,
January 1997.
30. Meeting between Manufacturers of Emission Controls Association and U.S. Environmental
Protection Agency, April 1995.
31. Voss, K., Bulent, Y., Hirt, C., andFarrauto, R., "Performance Characteristics of a Novel
Diesel Oxidation Catalyst," SAE Paper 940239, 1994.
32. Johnson, J., Bagley, S., Gratz, L., Leddy, D., "A Review of Diesel Particulate Control
Technology and Emissions Effects - 1992 Horning Memorial Award Lecture," SAE Paper
940233, 1994.
33. California Air Resources Board, Mail-Out #91-42.
34. Konno, M., Chikahisa, T., Murayama, T., "Reduction of Smoke and NOx by Strong
Turbulence Generated During the Combustion Process in D.I. Diesel Engines," SAE Paper
920467, 1992.
68
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Chapter 3: Technological Feasibility
35. International Standards Organization, 8178-4, "Reciprocating internal combustion
engines—Exhaust emission measurement—Part 4: Test cycles for different engine applications."
36. Memorandum from Mike Samulski, U.S. EPA, to Docket #A-96-40, "Selection of Duty
Cycle to Propose for High-Speed CI Marine Engines," February 19, 1997.
37. Southwest Research Institute, "Emission Testing of Nonroad Compression Ignition
Engines," prepared for U.S. Environmental Protection Agency, September 1995.
38. Letter from Michael S. Brand at Cummins to Bill Charmley at EPA, November 13, 1995.
39. Acurex Environmental, "Locomotive Technologies to Meet SOP Emission Standards,"
Prepared for the U.S. Environmental Protection Agency, August 13, 1997.
40. Environmental Transportation Consultants, "Shipboard Marine Engines Emission Testing
for the United States Coast Guard," Delivery Order No. 31, 1995.
41. Lloyd's Register, "Marine Exhaust Emission Research Programme; Steady-State Operation,"
1990.
42. Lloyd's Register, "Marine Exhaust Emissions Research Programme; Steady-State Operation;
Slow Speed Addendum," 1991.
43. Wilbur, C., "Marine Diesel Engines," Butterworth & Heinemann Ltd, 1984.
44. Memorandum from Mark Wolcott to Charles Gray, "Ambient Temperatures Associated with
High Ozone Concentrations," U.S. Environmental Protection Agency, September 6, 1984.
45. "Heavy-duty Diesel Engines Controlled by Onboard Computers: Guidance on Reporting and
Evaluating Auxiliary Emission Control Devices and the Defeat Device Prohibition of the Clean
Air Act," U.S. EPA, October 15, 1998.
46. Annex VI of MARPOL 73/78, "Technical code of control of Emissions of Nitrogen Oxides
for Marine Diesel Engines," October 22, 1997.
47. See reference 37—Southwest Research Institute
48. Letter from Michael S. Brand at Cummins to Bill Charmley at EPA, November 13, 1995.
49. See reference 40—Environmental Transportation Consultants
50. See reference 40—Environmental Transportation Consultants
51. See reference 41—Lloyd's Register, 1990
52. See reference 42—Lloyd's Register, 1991
69
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Regulatory Impact Analysis
53. Gilmer, Johnson, Introduction to Naval Architecture. U.S. Naval Institute, 1992, p. 251.
54. Taylor, C., The Internal Combustion Engine in Theory and Practice. MIT Press, 1990, p.
448.
55. Hey wood, J., Internal Combustion Engine Fundamentals. McGraw-Hill. New York. 1988.
p. 887.
56. Primus, R., Hoag, K., "Fundamentals of Reciprocating Engine Performance-Class Notes,"
Prepared August 1995.
57. See reference 42-Lloyd's Register
58. Memorandum from Jeff Carmody, Santa Barbara County Air Pollution Control District, to
Mike Samulski, U.S. Environmental Protection Agency, "Marine Engine Replacement
Programs," July 21, 1997.
59. Phone conversation between Steven Moore, South Coast Air Quality Management District
and Mike Samulski, U.S. Environmental Protection Agency, July 30, 1997.
60. Memorandum from Jeff Carmody, Santa Barbara County Air Pollution Control District, to
Mike Samulski, U.S. Environmental Protection Agency, "Marine Engine Replacement
Programs," December 1, 1997.
61. Talwar, M., Crawford, E., Hart, D., "Low Emission Commercial Marine Engine
Development for the Santa Barbara County Air Pollution Control District," SAE Paper 950734,
1995.
62. Facsimile from Eric Peterson, Santa Barbara County Air Pollution Control District, to Mike
Samulski, U.S. Environmental Protection Agency, "Marine Engine Replacement Programs,"
April 1, 1998.
63. Hellen, G., "Technologies for Diesel Exhaust Emission Reduction," NAVSEA Workshop,
August 18, 1998.
64. The Bunker News Daily, "Flashpoint," MRC Publications, July 17, 1997, Vol. 1 No. 137,
www.bunkernews.com.
65. International Standards Organization 8217, 1987.
66. See reference 55-Heywood, p. 577.
67. Bastenhof, D., "Exhaust Gas Emission Measurements: A Contribution to a Realistic
Approach," CIMAC, May 1995.
68. See reference 67-Bastenhof
70
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Chapter 3: Technological Feasibility
69. See reference 67-Bastenhof
71
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Regulatory Impact Analysis
72
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Chapter 4: Economic Impact
CHAPTER 4: ECONOMIC IMPACT
EPA expects that in almost all cases, manufacturers will produce a complying marine engine
by adapting an engine that has been designed and certified to meet highway or nonroad emission
standards. This analysis considers the cost of these upgrades to the base engines as part of the impact
of new marine emission standards; variable costs are applied directly, with an additional fixed cost
added to apply the technologies to marine engines. The analysis arrives at the full cost impact by
considering changes to turbocharging and aftercooling applicable to marine engines.
This chapter describes EPA's approach to estimating the cost of complying with the new
standards. Both engine and vessel design are considered in determining a total cost impact. The
estimated aggregate cost to society is also considered, followed by an analysis of the impact on small
businesses.
I. Methodology
EPA has estimated a mix of current and proj ected technologies for complying with the proposed
emission standards. The costs of individual technologies are developed in considerable detail and
then combined according to the projections of technology changes for successive tiers of emission
standards. EPA developed the costs for individual technologies in cooperation with ICF,
Incorporated and Geraghty & Miller in a series of reports related to diesel engine emission
controls.1'2'3
To simplify the analyses, costs were examined for five types of engines representing five power
ranges. The five cases, shown in Table 4-1, cover four Category 1 engines and one Category 2
engine. The selected power ratings are intended to correspond with the displacement values used
to differentiate among the standards. The maximum listed value of 5,000 kW is intended merely to
reflect the upper end of the range of Category 2 engines.
Costs of control include variable costs (for incremental hardware costs, assembly costs, and
associated markups) and fixed costs (for tooling, R&D, and certification). Variable costs are marked
up at a rate of 29 percent to account for manufacturers' overhead and profit.4 For technologies sold
by a supplier to the engine manufacturers, an additional 29 percent markup is included for the
supplier's overhead and profit. The analysis also includes consideration of lifetime operating costs
where applicable. The result is a total estimated incremental cost for individual engines of various
sizes.
Table 4-1 also includes information on current product offerings and sales volumes, which is
needed to calculate amortized fixed costs for individual engines. Estimated sales and product
offerings were compiled from the PSR database based on historical 1997 information. For the largest
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Regulatory Impact Analysis
engines, some sales volumes were modified slightly to take into account recent data related to vessel
populations.
Table 4-1
Power Ranges and Nominal Power for Estimating Costs (kW)
Engine Power
Ranges
37 - 225
225 - 560
560 - 1000
1000-2000
2000 - 5000
Nominal
Engine Power
100
400
750
1500
3000
Models
26
15
10
8
5
Annual
Sales*
3,284
1,579
142
130
68
Average Sales
per Model
126
105
14
16
14
* Excluding recreational.
Even though the analysis does not reflect all the possible technology variations and options that
are available to manufacturers, EPA believes that the projections presented here provide a cost
estimate representative of the different approaches manufacturers may ultimately take.
II. Overview of Technologies
The land-based engines that often serve as the base engines for marine diesel applications will
be changing as a result of new emission standards adopted for nonroad and locomotive engines.
Most new nonroad and locomotive engines rated over 37 kW will be subject to two new tiers of
standards spanning the next ten years. These engines will be designed, manufactured, and certified
to have reduced emissions. The technological challenge for developing compliant marine engines
is therefore to make the necessary modifications to the land-based engines for their use in the marine
environment without significantly increasing emission levels.
In the absence of emission standards for marine engines, manufacturers would have to decide
whether it would be more effective to marinize their low-emitting Tier 2 land-based engines, thus
maintaining a single base engine, or to continue to marinize unregulated or Tier 1 land-based
engines, thus maintaining separate production of older-technology engines for marine application.
This analysis is based on engine manufacturers choosing the latter, and accordingly assesses the
previously estimated variable costs of the land-based programs as an impact of the marine emission
standards. To the extent that manufacturers would simplify production by using their low-emitting
models anyway, the cost estimates developed in this analysis would overstate the actual impact of
the emission standards.
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Chapter 4: Economic Impact
As discussed in Chapter 3, manufacturers of Category 1 engines are expected to comply with
the proposed emission standards by conducting basic engine modifications, upgrading fuel systems,
adding some degree of electronic controls, and improving aftercooling systems. Manufacturers of
Category 2 engines are expected to redesign combustion chambers, improve high-pressure electronic
fuel injection systems, and upgrade or add turbocharging and aftercooling.
Except for the aftercooling changes, hardware improvements for nonroad and locomotive
engines should be transferrable to marine engines, in many cases with some degree of adaptation.
The analysis includes a substantial degree of development work to make adjustments for
turbocharger matching, reprogramming electronic control software, and other changes that may be
needed to prepare an engine for marine applications. Also, because manufacturers will in many cases
be producing new engine designs outside the normal product development cycle, extensive
development costs are included to design a marine version of a base engine, taking into account not
only direct expenses for controlling emissions, but also considering some need for re-optimizing
performance. Finally, marine engines rely on seawater (through a heat exchanger), not the ambient
air, for rej ecting heat from the engine and aftercooler. The cost of adding these systems are therefore
presented separately in this chapter for different sizes of marine engines.
The first step in estimating the incremental cost of new emission standards is to establish the
baseline technology package from which changes will be made. As described above, most of the
technologies included in the analysis of costs for the land-based rules are carried directly into the
analysis of costs for marine engines. Including these sets of technologies as a package defines both
baseline and projection scenarios. A more detailed assessment is required for turbocharging and
aftercooling. The PSR database provides information on sales and engine data for engine models
available for auxiliary and propulsion marine applications. Table 4-2 summarizes the sales-weighted
figures showing how many current engine sales include the various turbocharging and aftercooling
options. Table 3-2 provides similar information without breaking engines into different size ranges.
The predominance of naturally aspirated engines rated under 130 kW is contrasted with the nearly
universal use of turbocharging for bigger engines. The table also shows that most turbocharged
engines are equipped with jacket-water (or "single-circuit") aftercoolers, though a small number of
turbocharged engines in certain size ranges have either no aftercooling or the more sophisticated
separate-circuit aftercooling.
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Regulatory Impact Analysis
Table 4-2
Baseline Technologies for Marine Engines*
Engine Power
(kW)
100
400
750
1500
3000
Naturally
Aspirated
65%
0%
0%
0%
10%
Turbocharged
35%
100%
100%
100%
90%
Jacket-water
Aftercooling
15%
55%
100%
100%
80%
Separate-circuit
Aftercooling
0%
15%
0%
0%
10%
source: PSR Database.
*A11 numbers rounded to the nearest 5 percent.
As described in the cost analysis for the land-based nonroad engine rulemaking, manufacturers
are expected to develop engine technologies not only to reduce emissions, but also to improve engine
performance. While it is difficult to take into account the effect of ongoing technology development,
EPA is concerned that assessing the full cost of the anticipated technologies as an impact of new
emission standards would inappropriately exclude from consideration the expected benefits for
engine performance, fuel consumption, and durability.3 Short of having sufficient data to predict the
future with a reasonable degree of confidence, EPA faces the need to devise an alternate approach
to quantifying the true impact of the new emission standards. EPA requests comment on the most
appropriate way of accounting for these non-emission benefits.
III. Technology Costs
The total estimated cost impact of new emission standards is developed by considering the cost
of each of the anticipated technologies. The following paragraphs describe these technologies and
their application to marine engines. The analysis then combines these itemized costs into a
composite cost estimate for the range of marine engines affected by the rulemaking.
Cost estimates for electronic controls, fuel inj ection upgrades, and exhaust gas recirculation are
derived from estimates for nonroad engines. Variable costs for these technologies are carried into
this analysis. In some cases, cost figures represent an average across a broader power range or an
extrapolation to a bigger engine. Estimated R&D expenditures for these technologies and other
engine modifications are also considered. The anticipated R&D effort should be focused primarily
3While EPA does not anticipate widespread, marked improvements in fuel consumption,
small improvements on some engines may occur.
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Chapter 4: Economic Impact
on transferring established engine technologies to marine engines. Projected fixed costs are therefore
reduced from the levels anticipated for redesigning nonroad engines. EPA's general expectation is
that one-third of the previously anticipated level of R&D would be needed to successfully implement
the changes for marine engines.
Estimated levels of R&D in the analysis are developed for individual technologies to show the
incremental effect of combining different levels of emission control. Engine design in practice,
however, is much more integrated. Table 4-3 shows a weighted total of the combined R&D costs
calculated for each size engine to integrate the projected package of technologies for each tier of
emission limits. To put these large capital expenditures in context, the analysis is based on each $1
million of R&D consisting of about three engineer-years and four technician-years of effort, plus
nearly $500,000 for testing-related expenses.
Table 4-3
Total Estimated R&D Expenditures per Engine Family
Tier 2
Tier3
lOOkW
$600,000
$1,060,000
400 kW
$610,000
$1,100,000
750 kW
$1,400,000
$1,890,000
ISOOkW
$1,400,000
$2,250,000
3000 kW
$1,870,000
$2,250,000
As described in the notice of proposed rulemaking, EPA intends to require that manufacturers
comply with emission limits at any speed and load that can occur on a vessel. While these so-called
off-cycle requirements may increase the difficulty of meeting the emission limits, EPA believes it
is not appropriate to consider additional costs for manufacturers to comply with them. This is
because managing engine operation to avoid unacceptable variation in emission levels is expected
to be achievable by more effective utilization of the technologies that will be usedto meet the
emission limits more boradly, rather than by use of additional hardware. For example, electronically
controlled common rail fuel systems can be reprogrammed to adjust a wide range of injection
variables under certain operating conditions to avoid excessive emissions. This approach would
involve no additional variable cost. The estimated R&D expenditures are intended to reflect the time
needed to address this. It is possible that manufacturers will need to retard inj ection timing for some
engines, which would result in a cost penalty for increased fuel consumption. This scenario is
considered as a sensitivity analysis in Section ni.J. below.
A. Electronic Controls
EPA anticipates that electronic controls will be an essential design element as emission limits
increase in stringency. Almost all engines rated over 560 kW are already equipped with electronic
controls, because of the associated performance improvements. Engines rated between 37 and 560
kW will need to add electronic controls to meet the proposed emission limits.
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Regulatory Impact Analysis
The analysis reaches an estimated cost for applying electronic controls in several steps, as
summarized in Table 4-4. First, the hardware is expected to be the same as that used for nonroad
engines, so costs are transferred directly from previous estimates. Second, an additional cost is
assessed to account for preventing corrosion in the wiring, connections, and the electronic controller
and to meet explosion-proof specifications or other marine-specific requirements. The increasing
use of electronic systems for navigation, communication, and inventory purposes has led to better,
lower cost approaches to producing more durable and reliable systems. These marine improvements
consist primarily of additional material to seal metal parts and joints and and stronger materials or
better fasteners for some components. Third, the R&D cost for programming the electronics for all
the applications of a single engine model is treated the same as adding two new calibrations to the
base engine.
Table 4-4
Electronic Controls
Component costs
Marine upgrade
Assembly, markup, and warranty
Hardware cost per engine
Total fixed costs
Fixed cost per engine
Composite Unit Cost
100 kW
$454
$50
$219
$723
$150,000
$290
$1,012
400 kW
$650
$75
$307
$1,032
$150,000
$348
$1,380
B. Fuel Injection Improvements
All engines are expected to see significant improvements in their fuel inj ection systems. Some
engines are expected to make incremental improvements to existing unit inj ector designs (see Table
4-5). Better control of injection timing and increased injection pressure contribute to reduced
emissions.
The rapidly growing demand for common rail fuel inj ection across engine sizes and applications
supports a projection of long-term use of common rail for all engines.5 The principal benefit of
common rail technology is that injection pressure is no longer dependent on engine speed, which,
in conjunction with electronic controls, greatly increases the flexibility of tailoring the injection
timing and profile to varying modes of operation. Though the technology development originated
with highway diesel engines, common rail designs have been tailored for application in much larger
engines.6 Cost estimates for common rail systems are summarized in Table 4-6.
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Chapter 4: Economic Impact
Table 4-5
Unit Injection Improvements
Component costs
Assembly, markup, and warranty
Hardware cost per engine
Total fixed costs
Fixed cost per engine
Composite Unit Cost
100 kW
$63
$32
$95
$45,000
$87
$182
400 kW
$98
$46
$144
$100,000
$232
$375
3000kW
$4,000
$1,882
$5,882
*
*
$5,882
*Fixed costs for developing unit injectors are included under Engine Modifications.
Table 4-6
Common Rail Fuel Injection
Component costs
Assembly, markup, and
warranty
Hardware cost per engine
Total fixed costs
Fixed cost per engine
Composite Unit Cost
100 kW
$80
$23
$103
$100,000
$193
$296
400 kW
$116
$34
$150
$100,000
$232
$381
750 kW
$205
$59
$264
$300,000
$5,153
$5,417
ISOOkW
$630
$183
$813
$300,000
$4,503
$5,315
3000kW
$1,500
$435
$1,935
$1,000,000
$17,933
$19,868
C. Engine Modifications
Manufacturers have continued to pursue improvements in basic engine technology in an effort
to improve operating performance while controlling emissions. Such variables include routing of
the intake air, piston crown geometry, and placement and orientation of injectors and valves. Most
of these variables affect the mixing of air and fuel in the combustion chamber. Small changes in
injection timing are also considered in this set of modifications. EPA expects that the base engines
from which the marine engines are derived will have been extensively redesigned for operation at
Tier 2 emission levels. Remaining engine modifications would then reflect the need to adapt these
79
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Regulatory Impact Analysis
engines for complying with marine emission limits, including requirements to maintain control of
emissions over the whole range of marine engine operation.
Because no performance improvements beyond those already achieved for nonroad engines are
anticipated, no discount for non-emission benefits are applied. Accounting for the full cost of engine
modifications as an impact of new emission standards also reflects the extensive effort needed to
conduct an overall recalibration and reoptimization of the engine according to the schedule dictated
by the implementation of Tier 2 emission limits. On the other hand, no fuel economy penalty for
retarded inj ection timing is included. EPA believes that manufacturers will either not need to retard
timing, or at least will be able to optimize other variables such as inj ection pressure and aftercooling
to overcome any effects of retarding timing. The possibility of a fuel penalty is considered in the
sensitivy analysis described in Section V below.
As described in the cost analysis for the land-based nonroad engine rulemaking, engine
modifications are expected to require extensive R&D and retooling, but no change in hardware costs.
The hardware costs included in this analysis for Category 2 engines are based on the different
technology projections for Tier 2 locomotive engines. Table 4-7 shows the estimated per-engine
costs for these modifications.
Table 4-7
Engine Modifications
Hardware cost per engine
Total fixed costs
Fixed cost per engine
Composite Unit Cost
lOOkW
—
$200,000
$386
$386
400 kW
—
$200,000
$463
$463
750 kW
—
$1,100,000
$18,893
$18,893
ISOOkW
—
$1,100,000
$16,510
$16,510
3000kW
$800
$1,500,000
$26,900
$27,700
D. Turbocharging
EPA expects that turbocharging will be needed by all marine diesel engines rated over 37 kW
to meet Tier 2 emission limits. As shown in Table 4-2, except for some engines rated below 225 kW
or above 2000 kW, all marine diesel engines are already turbocharged. Turbocharger costs for the
remaining engines were developed for EPA by Arcadis Geraghty and Miller.7 Since R&D costs were
not developed separately for turbocharging, EPA conservatively estimated that one-fourth of the
R&D required for a turbocharging and aftercooling system would be needed for adding
turbocharging alone. Total turbocharger cost impacts are presented in Table 4-8.
Turbocharging can be used to increase power, which would involve higher costs for virtually
all the powertrain components. This analysis, however, does not presume an increase in power or
improved fuel economy resulting from turbocharging. Rather, turbocharging in the context of
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Chapter 4: Economic Impact
emission controls is seen primarily as a technology that enables aftercooling, which has a great
potential to control NOx emissions. Manufacturers may choose to exploit new turbochargers to
improve performance, but EPA believes that such an approach would not be needed to comply with
emission standards. As described earlier, these non-emission benefits support the analytical
approach of assigning only half the cost of turbocharging as an impact of the proposed emission
standards.
Table 4-8
Turbocharging
Hardware cost per engine
Total fixed costs
Fixed cost per engine
Composite Unit Cost
100 kW
$208
$100,000
$193
$401
SOOOkW
$2,133
$300,000
$5,380
$7,513
E. Aftercooling
Cost estimates for adding or upgrading aftercooling systems were developed for EPA by Arcadis
Geraghty and Miller.8 Separate costs were developed for adding jacket-water aftercooling and
separate-circuit aftercooling (Tables 4-9 and 4-10, respectively). A third scenario of improving
technology can be determined by calculating the net increase in cost for converting from j acket-water
aftercooling to separate-circuit aftercooling (Table 4-11). The ample supply of cooling water and
its greater convection coefficient relative to air support EP A's belief that optimized separate-circuit
aftercooling systems can match or exceed the cooling capability of air-to-air cooling in land-based
engines.
Cost estimates were developed for separate-circuit aftercooling systems using tube-and-shell
heat exchangers. An alternative design sometimes used on marine vessels is keel cooling, in which
coolant is plumbed from the engine or aftercooler to the hull, where it is cooled by exposure to the
seawater. Upgrading systems that rely on keel cooling would involve somewhat higher initial costs,
but this cost premium is offset by lower operating costs for maintenance or rebuild. Costs related
to keel cooling systems are not considered separately in this analysis.
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Regulatory Impact Analysis
Table 4-9
Incremental Cost of Adding Jacket-Water Aftercooling
Component costs
Assembly, markup, and warranty
Hardware cost per engine
Total fixed costs
Fixed cost per engine
Composite Unit Cost
100 kW
$237
$383
$620
$400,000
$826
$1,446
400kW
$899
$746
$1,645
$550,000
$3,092
$4,737
Table 4-10
Incremental Cost of Adding Separate-circuit Aftercooling
Component costs
Assembly, markup, and warranty
Hardware cost per engine
Total fixed costs
Fixed cost per engine
Composite Unit Cost
100 kW
$596
$790
$1,386
$480,000
$992
$2,387
400kW
$1,800
$1,765
$3,565
$660,000
$3,711
$7,276
3000 kW
$20,492
$11,113
$31,605
$1,440,000
$27,631
$59,236
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Chapter 4: Economic Impact
Table 4-11
Incremental Cost of Converting from Jacket-Water to Separate-circuit Aftercooling
Component costs
Assembly, markup, and
warranty
Hardware cost per engine
Total fixed costs
Fixed cost per engine
Composite Unit Cost
lOOkW
$359
$407
$766
$80,000
$166
$932
400 kW
$901
$1,019
$1,920
$110,000
$619
$2,539
750 kW
$1,701
$2,011
$3,712
$140,000
$2,573
$6,285
ISOOkW
$3,151
$3,189
$6,340
$200,000
$3,212
$9,552
3000kW
$5,964
$5,143
$11,107
$240,000
$4,605
$15,712
F. Exhaust Gas Recirculation
Exhaust gas recirculation (EGR) reduces NOx emissions by mixing a portion of the exhaust
gases into the intake air. Adding an EGR cooler to a basic EGR system increases the effectiveness
of controlling NOx emissions by further suppressing temperatures in the combustion chamber. EGR
has the advantage that it can be focused on the light-load modes of operation where NOx emissions
are most difficult to control. This also enables the designer to add moderate to extensive levels of
EGR to control NOx, with minimal negative effects on overall fuel economy, which is most
important at high-load operation.
Proposed Tier 3 emission limits for engines with per-cylinder displacement less than 2.5 liters
(roughly corresponding with 560 kW) are more stringent than for bigger engines (see Table 1-2).
The more stringent standards will likely require cooled EGR systems. EPA believes that the design
challenges associated with EGR cooling make this a less attractive design option for larger engines,
whose low sales volumes make it more difficult to distribute high fixed costs. The less stringent
emission limits for these engines reflect this difficulty. As described in a sensitivity analysis below,
injection timing retard can be used as a supplemental measure if an engine with hot EGR is unable
to sufficiently control NOx emissions.
Estimated system costs for EGR are derived from the similar analyses for highway and nonroad
engines. Applying these cost estimates to marine engines requires significant extrapolation to the
high-power engines. While component costs can be considered approximate, the cost impact of
adding EGR comes predominantly from amortizing R&D costs. The estimated level of $500,000
for R&D and other fixed costs for 100 and 400 kW engines reflects the extensive development
required to adapt cooled EGR systems expected in nonroad engines for the counterpart marine
engines. For larger engines, the additional R&D needed to address unique engine issues is offset by
the lower sophistication of the hot EGR systems. These costs are summarized in Table 4-12.
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Regulatory Impact Analysis
One particular design challenge that engineers will have to address is the recirculation of
paniculate matter through the engine. The principal concern is for degradation of the lubricating oil
as the oil absorbs significant amounts of particulate matter. In anticipation of EGR for highway
engines, motor oil producers have developed a product that can absorb these levels of particulate
matter without losing its lubricating properties. To account for the expense of higher-quality oils,
the analysis adds an operating cost based on a 2 percent increase in the cost of oil. For companies
that conduct oil sampling analysis in lieu of periodic oil changes, the listed life-cycle cost estimates
overstate the effect of improved oils.
Table 4-12
Exhaust Gas Recirculation
Electronic EGR valve
EGR tubing
EGR cooler
Component costs
Assembly, markup, and
warranty
Hardware cost per engine
Total fixed costs
Fixed cost per engine
Composite Unit Cost
Life-cycle oil cost (npv)
lOOkW
$35
$9
$48
$92
$45
$137
$500,000
$2,896
$3,033
$20
400 kW
$43
$22
$64
$129
$59
$188
$500,000
$3,475
$3,663
$56
750 kW
$70
$45
—
$115
$64
$179
$500,000
$8,588
$8,767
$167
ISOOkW
$130
$90
—
$220
$105
$325
$500,000
$7,504
$7,830
$311
3000kW
$240
$180
—
$420
$203
$623
$500,000
$8,967
$9,589
$715
G. Rebuild Costs
Operating data related to marine engines indicates that rebuild or remanufacture typically occurs
multiple times for an engine, especially for larger engines. To the extent that manufacturers are
adding new hardware to an engine to comply with emission requirements, there may be an increase
in the cost of repair or replacement of parts over the life of an engine. This analysis includes an
estimate of increased operating costs by projecting a schedule of parts replacement coinciding with
periodic rebuilds. To calculate a total cost for each rebuild, the analysis provides for a rebuild rate
of one-third of total long-term variable costs for each rebuild event. For some technologies, this
represents a scenario of one-third of all engines replacing all the hardware in the system (such as
turbochargers). For other technologies, this represents a scenario of all engines needing replacement
of one-third of the value of new or improved components. For example, a rebuilder is not expected
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Chapter 4: Economic Impact
to replace all the elements of an electronic control system at the point of rebuild; rather, after
searching for defective or potentially defective parts, a rebuilder is expected to replace individual
components on an as-needed basis. The value of replacement parts is calculated on a long-term
basis, as described below, then marked up by a factor of three to account for the higher cost of
aftermarket parts.
Turbocharging and aftercooling are the only technologies expected to require an increase in
labor hours to rebuild an engine. Since these systems are virtually custom-built in commercial
vessels, the analysis uses the same assembly times as were used to develop costs for new engines.
The rebuild schedule for Category 1 engines is based on a sixteen-year life, with two rebuilds
occurring at the end of the fifth and tenth years. This represents median values for the fleet of
engines, rather than incorporating scrappage rates and additional rebuilds on a subset of the fleet.
Similarly, Category 2 engine rebuilds are based on a 23-year lifetime with three rebuilds occurring
after years six, twelve, and eighteen. Lifetime costs are discounted to a net-present-value figure at
the point of sale using a 7 percent discount rate. Rebuild costs are shown in Table 4-13.
85
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Regulatory Impact Analysis
Table 4-13
Incremental Rebuild Costs
lOOkW
400 kW
750 kW
ISOOkW
3000kW
Incremental hardware costs
Electronic controls
Common rail
Unit injection
Turbocharger
Jacket-water aftercooling
Separate-circuit aftercooling
Aftercooling upgrade
Exhaust gas recirculation
$323
$66
$40
$133
$152
$381
$230
$59
$464
$96
$62
—
$575
$1,152
$577
$82
—
$169
—
—
—
$2,237
$1,089
$74
—
$520
—
—
—
$5,642
$2,017
$141
—
$1,238
$2,560
$1,365
—
$13,115
$3,817
$269
Incremental labor hours:
Turbocharger
Jacket-water aftercooling
Separate-circuit aftercooling
Aftercooling upgrade
Exhaust gas recirculation
1
5
11
6
1
—
5
20
15
1
—
—
40
30
1
—
—
60
45
1
6
—
90
68
1
H. Certification and Compliance
EPA has significantly reduced certification requirements in recent years, but manufacturers are
nevertheless responsible for generating a minimum amount of test data and other information to
demonstrate compliance with emission standards. Table 4-14 lists the expected costs for different
sizes of engines, including the amortization of those costs over five years of engine sales. Estimated
certification costs are based on two engine tests and $20,000 worth of engineering and clerical effort
to prepare and submit the required information.
Until engine designs are significantly changed, engine families can be recertified each year using
carryover of the original test data. Since these engines are currently not subject to any emission
requirements, the analysis includes a cost to recertify an upgraded engine model every five years.
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Chapter 4: Economic Impact
Costs for production line testing (PLT) are summarized in Table 4-15. These costs are based
on testing 1 percent of total estimated sales, then distributing costs over the fleet. Listed costs for
engine testing presume no need to build new test facilities, since most or all manufacturers already
have testing facilities available. The proposal also includes provisions to exclude the smallest
companies from requirements to conduct production line testing.
Table 4-14
Certification
Total fixed costs
Fixed cost per engine
Composite Unit Cost
lOOkW
$40,000
$77
$77
400 kW
$40,000
$93
$93
750 kW
$50,000
$859
$859
ISOOkW
$50,000
$750
$750
3000kW
$60,000
$1,076
$1,076
Table 4-15
Costs for Production Line Testing
Cost per test
Testing rate
Cost per engine
lOOkW
$10,000
1%
$100
400 kW
$10,000
1%
$100
750 kW
$15,000
1%
$150
ISOOkW
$15,000
1%
$150
3000kW
$20,000
1%
$200
I. Total Engine Costs
These individual cost elements can be combined into a calculated total for each tier of new
emission limits by assessing the degree to which the different technologies will be deployed. As
described above, comparing the projected need for specific technologies can be compared to the
technology baseline to determine the changes that will occur in the Tier 2 and Tier 3 time frames.
For Tier 2 emission limits, manufacturers are expected to rely on turbocharged engines with
extensive modification to injection systems (including some additional use of electronic controls),
and basic engine design. Some engines are expected to require new or improved aftercooling
systems. In general, the projected utilization of each technology is expected to match that of land-
based counterpart engines. With respect to aftercooling, jacket-water cooling systems are considered
equivalent to air-to-water designs, and separate-circuit systems are considered equivalent to air-to-air
designs. Since the Tier 2 emission limits for marine engines are in most cases less stringent than
those finalized for the land-based counterpart engines, projecting the same degree of technology
deployment represents a very conservative estimate of cost impacts. This approach is nevertheless
87
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Regulatory Impact Analysis
used to estimate Tier 2 costs, because it accounts for the uncertainties associated with the
marinization process and the effect of differing test cycles and compliance requirements.
To comply with Tier 2 emission limits, manufacturers are expected to take a variety of
approaches to improve fuel systems, making incremental improvements to the various current
designs. Unit inj ection systems can generally be further optimized for higher inj ection pressures and
improved rate shaping capability. Nonroad engines with the highest sales volumes have begun
converting to common rail fuel systems to take advantage of the step improvement in control of
injection variables. EPA believes that these fuel systems will be used similarly for land-based and
marine engines. Some engines will also likely use improved aftercooling technologies.
Projecting the mix of technologies for complying with Tier 3 emission limits necessarily
involves a greater degree of uncertainly. Recent technology developments for highway and nonroad
engines, however, has already done much to establish the emission-control potential of several of
the anticipated technology improvements. In this analysis, EPA based the estimated Tier 3 costs on
a scenario of universal deployment of common rail fuel injection, separate-circuit aftercooling, and
exhaust gas recirculation. Most of the benefit of Tier 2 engine modifications will carry over to Tier
3 designs; however, an expected additional effort for improving and optimizing basic engine design
is estimated to be half as much as that required to reach Tier 2 levels.
Inj ection timing retard is not part of the package of measures manufacturers are expected to take
to comply with Tier 3 emission limits. Manufacturers may eventually choose to rely on timing
retard, either to achieve an additional level of emission control or to avoid a more costly alternative
technology. A sensitivity analysis, described in Section J below, evaluates the potential cost impacts
of timing retard or other alternatives that may increase fuel consumption. In any case, EPA will
review the feasibility and estimated cost of compliance with the Tier 3 emission limits in the 2003
Review.
Factoring in the degree of deployment and adding up the costs of the individual technologies
results in a total estimated cost impact for engines designed and produced to meet emission limits.
As shown in Table 4-16, estimated costs for complying with Tier 2 emission limits increase with
increasing power ratings. Estimated price impacts range from $2,600 for a 100 kW engine to
$54,000 for a 3,000 kW engine. Increased rebuild costs add to the total estimated impact, though
to a much lesser degree than from the expected increase in new engine prices (Table 4-17).
Similarly, cost increases for Tier 3 engines are shown in Table 4-18, with total costs ranging from
$5,300 to $45,000. The percentages listed in the tables represent the anticipated change in the
individual technologies and should not be confused with the total anticipated deployment of these
technologies.
As described in the nonroad diesel rulemaking, long-term costs would be reduced by two
principal factors. First, fixed costs are assessed for five years, after which they are fully amortized
and are therefore no longer part of the cost calculation. Second, manufacturers are expected to learn
over time to produce the engines with the new technologies at a lower cost. This should be especially
true with marine engines. Because of the relatively low sales volumes, manufacturers are less likely
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Chapter 4: Economic Impact
to put in the extra R&D effort for low-cost manufacturing. As production starts, assemblers and
production engineers would then be expected to find significant improvements in fine-tuning these
designs. To reflect this learning, variable costs are reduced by 20 percent beginning with the third
year of production and an additional 20 percent beginning with the sixth year of production. Table
4-18 also lists the long-term cost estimates for these engines the sixth and subsequent years of
production after incorporating these two changes. Reductions in long-term cost estimates ranging
from 50 to 90 percent demonstrate the predominance of research and other fixed costs in the total
estimated impact of the emission standards.
Characterizing these estimated costs in the context of their fraction of the total purchase price
and life-cycle operating costs is helpful in gauging the economic impact of the new standards.
Although the incremental cost projections increase dramatically with increasing power rating, they
in fact represent a comparable price change relative to the total price of the engine. The estimated
first-year cost increases for all engines are at most 3 percent of estimated vessel prices, with even
lower long-term effects, as described above.
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Table 4-16
Engine Costs—Tier 2
Electronic controls
Common rail
Unit injection upgrade
Engine modifications
Turbocharger
Jacket-water
aftercooling
Separate-circuit
aftercooling
Upgrade to separate-
circuit aftercooling
Certification + PLT
Total Engine Costs
100 kW
Fraction*
75%
0%
100%
100%
65%
30%
10%
15%
100%
0%
Cost
$759
—
$182
$386
$261
$434
$231
$140
$177
$2,577
400 kW
Fraction*
75%
0%
100%
100%
0%
30%
0%
30%
100%
—
Cost
$1,035
—
$375
$463
—
$1,421
—
$762
$193
$4,249
750 kW
Fraction*
0%
100%
0%
100%
0%
0%
0%
0%
100%
0%
Cost
—
$5,417
—
$18,893
—
—
—
—
$1,009
$25,319
ISOOkW
Fraction*
0%
100%
0%
100%
0%
0%
0%
0%
100%
—
Cost
—
$5,315
—
$16,510
—
—
—
—
$900
$22.725
3000kW
Fraction*
0%
0%
100%
100%
10%
0%
10%
80%
100%
0%
Cost
—
—
$5,882
$27,700
$751
—
$5,924
$12,570
$1,276
$54,103
*"Fraction" denotes the percentage of engines estimated to require each of the new or improved technologies.
-------
Table 4-17
Rebuild Costs—Tier 2
100 kW
Fraction*
Cost
400 kW
Fraction*
Cost
750 kW
Fraction*
Cost
ISOOkW
Fraction*
Cost
3000kW
Fraction*
Cost
Incremental hardware costs:
Electronic controls
Common rail
Unit injection upgrade
Turbocharger
Jacket-water aftercooling
Separate-circuit aftercooling
Upgrade to separate-circuit
aftercooling
Hardware cost per engine
Incremental labor costs:
Total cost per rebuild
Total operating cost (npv)
75%
0%
100%
65%
30%
10%
15%
—
—
—
—
$242
—
$40
$87
$46
$38
$34
$487
$116
$603
$603
75%
0%
100%
0%
30%
—
30%
—
—
—
—
$348
—
$62
—
$173
—
$173
$756
$168
$924
$924
0%
100%
0%
0%
0%
0%
0%
—
—
—
—
—
$169
—
—
—
—
—
$169
$0
$169
$169
0%
100%
0%
0%
0%
0%
0%
—
—
—
—
—
$520
—
—
—
—
—
$520
$0
$520
$520
0%
0%
100%
10%
0%
10%
80%
—
—
—
—
—
—
$2,560
$137
—
$1,311
$3,054
$7,062
$1,778
$8,840
$8,840
"Fraction" denotes the percentage of engines estimated to require each of the new or improved technologies.
-------
Table 4-18
Engine Costs—Tier 3
Electronic controls
Common rail
Engine modifications
Separate-circuit
aftercooling
Upgrade to separate-
circuit aftercooling
Exhaust gas
recirculation
Certification + PLT
Total Engine Costs
(yr. 1-5)
Total Engine Costs
(yr. 6 and later)
lOOkW
Fraction*
25%
100%
50%
45%
30%
100%
100%
—
—
Cost
$253
$296
$193
$1,070
$280
$3,033
$177
$5,303
$1,112
400 kW
Fraction*
25%
100%
50%
0%
55%
100%
100%
—
—
Cost
$345
$381
$232
—
$1,396
$3,663
$193
$6,210
$1,829
750 kW
Fraction*
0%
0%
50%
0%
100%
100%
100%
—
—
Cost
—
—
$9,446
—
$6,285
$8,767
$1,009
$25,507
$5,601
ISOOkW
Fraction*
0%
0%
50%
0%
100%
100%
100%
—
—
Cost
—
—
$8,255
—
$9,552
$7,830
$900
$26,537
$10,659
3000kW
Fraction*
0%
100%
50%
0%
0%
100%
100%
—
—
Cost
—
$19,868
$13,850
—
—
$9,589
$1,276
$44,583
$3,169
'"Fraction" denotes the percentage of engines estimated to require each of the new or improved technologies.
-------
Table 4-19
Rebuild Costs—Tier 3
100 kW
Fraction*
Cost
400 kW
Fraction*
Cost
750 kW
Fraction*
Cost
ISOOkW
Fraction*
Cost
3000kW
Fraction*
Cost
Incremental hardware costs:
Electronic controls
Common rail
Separate-circuit
aftercooling
Upgrade to separate-
circuit aftercooling
Eshaust gas recirculation
Hardware cost per engine
Incremental labor costs:
Total Cost per Rebuild
Total Engine Cost (npv)
Life-cycle oil cost (npv)
Total operating cost (npv)
25%
100%
45%
30%
100%
—
—
—
—
—
—
$81
$66
$172
$69
$59
$446
$217
$663
$810
$20
$829
25%
100%
0%
55%
100%
—
—
—
—
—
—
$116
$96
—
$317
$82
$611
$259
$870
$1,063
$56
$1,119
0%
0%
0%
100%
100%
—
—
—
—
—
—
—
—
—
$1,089
$74
$1,162
$868
$2,030
$2,480
$167
$2,647
0%
0%
0%
100%
100%
—
—
—
—
—
—
—
—
—
$2,017
$141
$2,157
$1,288
$3,445
$4,208
$311
$4,519
0%
100%
0%
0%
100%
—
—
—
—
—
—
—
$1,238
—
—
$269
$1,507
$28
$1,535
$2,159
$715
$2,874
"Fraction" denotes the percentage of engines estimated to require each of the new or improved technologies.
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Regulatory Impact Analysis
J. Sensitivity
There has been some concern expressed that the technologies used to meet emission
requirements for land-based engines will be less effective at controlling emissions from marine
engines. Some of the reasons suggested for needing a more aggressive approach include the change
in duty cycle, the effects of "marinizing" an engine, and the need to comply with emission limits
across not-to-exceed zones. Manufacturers could rely on injection timing retard as a technology
option for achieving an additional measure of NOx control. Also, manufacturers may choose, for
example, to avoid the high R&D costs of implementing a new technology for an engine family with
low sales volume by relying on timing retard as a lower-cost alternative. In addition, manufacturers
using EGR may need to add exhaust gases during medium- and high-load operation to the point that
there would be an increase in fuel consumption that cannot be offset by improvements such as better
control of fuel injection. EPA therefore conducted a sensitivity analysis to show the costs associated
with a fuel penalty resulting from relying on retarded timing or EGR.
Because the requirement to control emissions throughout an engine's operating range poses the
greatest challenge at low speeds and loads, EPA calculated the costs of increasing fuel consumption
by one percent at modes 2 and 3 and by three percent at mode 4 (lightest load operation). Using the
weightings for the composite duty cycle, increased life-cycle fuel consumption from this net 1.0
percent fuel penalty can be calculated and then discounted to the present at a 7 percent rate. The
resulting estimated net-present-value cost increase ranges from $400 for a 100 kW engine to $ 19,000
for a 3000 kW engine. Considering the established effectiveness of timing retard as a strategy to
control NOx emissions, this may be considered a viable approach, either as a substitute or a
supplemental technology.
IV. Aggregate costs
The above analysis presents unit cost estimates for each power category. These costs represent
the total set of costs borne by engine manufacturers to comply with emission standards. With current
data for engine and vessel sales for each category and projections for the future, these costs can be
translated into projected direct costs to the nation for the new emission standards in any year.
Aggregate costs are estimated at about $19 million in the first year the new standards apply,
increasing to a peak of about $57 million in 2008 as increasing numbers of engines become subject
to the new standards. The following years show a drop in aggregate costs as the per-unit cost of
compliance decreases, resulting in aggregate costs of about $14 million in 2015, followed by slowly
growing costs due to increasing sales over time.
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Chapter 4: Economic Impact
Chapter 4 References
1 ."Estimated Economic Impact of New Emission Standards for Heavy-Duty On-Highway
Engines," Acurex Environmental Corporation Final Report (FR 97-103), March 31, 1997. The
Acurex Environmental Corporation has since changed its name to Arcadis Geraghty & Miller.
2."Incremental Costs for Nonroad Engines: Mechanical to Electronic," Memorandum from Lou
Browning, Acurex Environmental, to Alan Stout, EPA, April 1, 1997.
3."Incremental Cost Estimates for Marine Diesel Engine Technology Improvements,"
Memorandum from Louis Browning and Kassandra Genovesi, Arcadis Geraghty & Miller, to
Alan Stout, EPA, [September 12, 1998].
4."Update of EPA's Motor Vehicle Emission Control Equipment Retail Price Equivalent (RPE)
Calculation Formula," Jack Faucett Associates, Report No. JACKFAU-85-322-3, September
1985.
5. "The Year in Review: The Beat Goes On," Diesel Progress, June 1998, pp. 42, 44, 68.
6."Cat Gears Up Next Generation Fuel Systems," Diesel Progress, August 1998, p. 82.
7."Incremental Cost Estimates for Marine Diesel Engine Technology Improvements,"
Memorandum from Louis Browning and Kassandra Genovesi, Arcadis Geraghty & Miller, to
Alan Stout, EPA, [September 12, 1998].
8."Incremental Cost Estimates for Marine Diesel Engine Technology Improvements,"
Memorandum from Louis Browning and Kassandra Genovesi, Arcadis Geraghty & Miller, to
Alan Stout, EPA, [September 12, 1998].
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Regulatory Impact Analysis
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Chapter 5: Environmental Impacts
CHAPTER 5: ENVIRONMENTAL IMPACTS
Today's proposed regulations for compression-ignition marine engines focus on exhaust
emission reductions of HC, NOx, CO, and PM. The purpose of this chapter is to describe the
expected environmental impacts of the proposed emission standards. Specifically, the first part of
this chapter will discuss the health and welfare impacts of the pollutants covered by this proposal.
The second part of this chapter estimates the total nationwide emissions inventory for marine diesel
engines and projects future emissions and emission reductions associated with this proposed rule.
I. Health and Welfare Concerns
As part of the periodic review of the ozone and PM air quality standards required under the
Clean Air Act, EPA has reassessed the impacts of ozone and PM on human health and welfare,
taking into account peer-reviewed scientific information. The paragraphs below summarize some
of EPA's current concerns, as compiled in the Agency's Criteria Documents and Staff Papers for
ozone and PM. The Criteria Documents prepared by the Office of Research and Development
consist of EPA's latest summaries of scientific and technical information on each pollutant. The
Staff Papers on ozone and PM prepared by the Office of Air Quality Planning and Standards
summarize the policy-relevant key findings regarding health and welfare effects.
A. Ozone
Ground level ozone is formed when hydrocarbons and oxides of nitrogen react in the presence
of sunlight. Over the past few decades, many researchers have investigated the health effects
associated with both short-term (one- to three-hour) and prolonged acute (six- to eight-hour)
exposures to ozone. In the past decade, numerous controlled-exposure studies of moderately
exercising human subjects have been conducted which collectively allow a quantification of the
relationships between prolonged acute ozone exposure and the response of people's respiratory
systems under a variety of environmental conditions. To this experimental work has been added
field and epidemiological studies which provide further evidence of associations between short-term
and prolonged acute ozone exposures and health effects ranging from respiratory symptoms and lung
function decrements to increased hospital admissions for respiratory causes. In addition to these
health effects, daily mortality studies have suggested a possible association between ambient ozone
levels and an increased risk of premature death.
Most of the recent controlled-exposure ozone studies have shown that respiratory effects similar
to those found in the short-term exposure studies occur when human subjects are exposed to ozone
concentrations as low as 0.08 ppm while engaging in intermittent, moderate exercise for six to eight
hours. These effects occur even though ozone concentrations and levels of exertion are lower than
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Regulatory Impact Analysis
in the earlier short-term exposure studies. They appear to build up over time, peaking in the six- to
eight-hour time frame. Other effects, such as the presence of biochemical indicators of pulmonary
inflammation and increased susceptibility to infection, have also been reported for prolonged
exposures and, in some cases, for short-term exposures. Although the biological effects reported in
laboratory animal studies can be extrapolated to human health effects only with great uncertainty,
a large body of toxicological evidence exists which suggests that repeated exposures to ozone causes
pulmonary inflammation similar to that found in humans and over periods of months to years can
accelerate aging of the lungs and cause structural damage to the lungs.
In addition to human health effects, ozone is known to adversely affect the environment in many
ways. These effects include reduced yield for commodity crops, for fruits and vegetables, and
commercial forests; ecosystem and vegetation effects in such areas as National Parks (Class I areas);
damage to urban grass, flowers, shrubs, and trees; reduced yield in tree seedlings and noncommercial
forests; increased susceptibility of plants to pests; materials damage; and reduced visibility. Nitrogen
oxides (NOx), key precursors to ozone, also result in nitrogen deposition into sensitive nitrogen-
saturated coastal estuaries and ecosystems, causing increased growth of algae and other plants.
B. Particulate Matter
Particulate matter (PM) represents a broad class of chemically and physically diverse substances
that exist as discrete particles (liquid droplets or solids) over a wide range of sizes. Human-
generated sources of particles include a variety of stationary and mobile sources. Particles may be
emitted directly to the atmosphere or may be formed by transformations of gaseous emissions such
as sulfur dioxide or nitrogen oxides. The maj or chemical and physical properties of PM vary greatly
with time, region, meteorology, and source category, thus complicating the assessment of health and
welfare effects as related to various indicators of particulate pollution. At elevated concentrations,
particulate matter can adversely affect human health, visibility, and materials. Components of
particulate matter (e.g., sulfuric or nitric acid) contribute to acid deposition.
Key EPA findings can be summarized as follows:
1. Health risks posed by inhaled particles are affected both by the penetration and deposition of
particles in the various regions of the respiratory tract, and by the biological responses to these
deposited materials.
2. The risks of adverse effects associated with deposition of ambient particles in the thorax
(tracheobronchial and alveolar regions of the respiratory tract) are markedly greater than for
deposition in the extrathoracic (head) region. Maximum particle penetration to the thoracic
regions occurs during oronasal or mouth breathing.
3. The key health effects categories associated with PM include premature death; aggravation of
respiratory and cardiovascular disease, as indicated by increased hospital admissions and
emergency room visits, school absences, work loss days, and restricted activity days; changes
in lung function and increased respiratory symptoms; changes to lung tissues and structure; and
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Chapter 5: Environmental Impacts
altered respiratory defense mechanisms. Most of these effects have been consistently associated
with ambient PM concentrations, which have been used as a measure of population exposure,
in a large number of community epidemiological studies. Additional information and insights
on these effects are provided by studies of animal toxicology and controlled human exposures
to various constituents of PM conducted at higher than ambient concentrations. Although
mechanisms by which particles cause effects are not well known, there is general agreementthat
the cardio-respiratory system is the major target of PM effects.
4. Based on a qualitative assessment of the epidemiological evidence of effects associated with
PM for populations that appear to be at greatest risk with respect to particular health endpoints,
the EPA has concluded the following with respect to sensitive populations:
a. Individuals with respiratory disease (e.g., chronic obstructive pulmonary disease, acute
bronchitis) and cardiovascular disease (e.g., ischemic heart disease) are at greater risk of
premature mortality and hospitalization due to exposure to ambient PM.
b. Individuals with infectious respiratory disease (e.g., pneumonia) are at greater risk of
premature mortality and morbidity (e.g., hospitalization, aggravation of respiratory
symptoms) due to exposure to ambient PM. Also, exposure to PM may increase
individuals' susceptibility to respiratory infections.
c. Elderly individuals are also at greater risk of premature mortality and hospitalization for
cardiopulmonary problems due to exposure to ambient PM.
d. Children are at greater risk of increased respiratory symptoms and decreased lung function
due to exposure to ambient PM.
e. Asthmatic individuals are at risk of exacerbation of symptoms associated with asthma, and
increased need for medical attention, due to exposure to PM.
5. There are fundamental physical and chemical differences between fine and coarse fraction
particles, and it is reasonable to expect that differences may exist between the two subclasses
of PM-10 in both the nature of potential effects and the relative concentrations required to
produce such effects. The specific components of PM that could be of concern to health include
those typically within the fine fraction (e.g., acid aerosols, sulfates, nitrates, transition metals,
diesel particles, and ultra fine particles), and those typically within the coarse fraction (e.g.,
silica and resuspended dust). While components of both fractions can produce health effects,
in general, the fine fraction appears to contain more of the reactive substances potentially linked
to the kinds of effects observed in the epidemiological studies. The fine fraction also contains
the largest number of particles and a much larger aggregate surface area than the coarse fraction
which enables the fine fraction to have a substantially greater potential for absorption and
deposition in the thoracic region, as well as for dissolution or absorption of pollutant gases.
With respect to welfare or secondary effects, fine particles have been clearly associated with the
impairment of visibility over urban areas and large multi-state regions. Fine particles, or major
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Regulatory Impact Analysis
constituents thereof, also are implicated in materials damage, soiling and acid deposition. Coarse
fraction particles contribute to soiling and materials damage.
Particulate pollution is a problem affecting localities, both urban and nonurban, in all regions
of the United States. Manmade emissions that contribute to airborne particulate matter result
principally from stationary point sources (fuel combustion and industrial processes), industrial
process fugitive particulate emission sources, nonindustrial fugitive sources (roadway dust from
paved and unpaved roads, wind erosion from cropland, etc.) and transportation sources. In addition
to manmade emissions, consideration must also be given to natural emissions including dust, sea
spray, volcanic emissions, biogenic emanation (e.g., pollen from plants), and emissions from wild
fires when assessing particulate pollution and devising control strategies.
C. Carbon Monoxide
Though carbon monoxide (CO) is not the primary focus of this rule, EPA is proposing new
standards for CO. CO has long been known to have substantial adverse effects on human health and
welfare, including toxic effects on blood and tissues, and effects on organ functions, and has been
linked to fetal brain damage, increased risk for people with heart disease, and reduced visual
perception, cognitive functions and aerobic capacity. Due to recent emission standards, the number
of areas in nonattainment for CO has greatly diminished in the past decade. There are approximately
20 remaining serious or moderate CO nonattainment areas.
D. Smoke
Smoke from diesel engines has long been associated with adverse effects on human welfare,
including considerable economic, visibility and aesthetic damage. The carbon particles that make
up diesel smoke cause reduced visibility; soiling of urban buildings, homes, personal property,
clothes, and skin; and are associated with increased odor, coughing, and eye irritation. In addition,
the particles causing visible smoke are the same as those associated with the significant threats to
human health described above for particulate matter.
II. Emission Reductions
For the purposes of this proposed regulation, EPA has divided marine diesel engines into three
categories. Category 1 engines are smaller engines used in recreational and light commercial
applications, Category 2 engines are medium sized engines such as those used in tugboats, and
Category 3 engines are the large engines used primarily for propulsion in ocean-going vessels.
Because of the distinctly different characteristics between the design and operation of the marine
diesel engines in these three categories, the proposed regulations focus on each category separately.
Also due to distinctions between the categories, different data sources and approaches were required
to develop an inventory for the three categories. The remainder of this chapter will describe the
inventory calculations for the categories separately then combine them to discuss the nationwide
benefits.
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Chapter 5: Environmental Impacts
A. Category 1
1. General Methodology
In the inventory calculations, Category 1 compression-ignition marine engines were divided into
recreational, commercial, and auxiliary applications. The applications were further divided into
power ranges which are consistent with the proposed standards. Each of the engine applications and
power ranges were modeled with distinct annual hours of operation, load factors, and average engine
lives. The basic equation for determining the emissions inventory, for a single year, from marine
engines is shown below:
Emissions =
rec,com,aux
ranges
population * power x load x annual use x emissionfactor)
This equation sums the total emissions for each of the power ranges and applications.
"Population" refers to the number of marine diesel engines greater than or equal to 37 kW but with
a displacement per cylinder of five liters or less estimated to be in the U.S. in a given year. "Power"
refers to the population-weighted average rated power for a given power range. Two usage factors
are included; "load" is the ratio between the average operational power output and the rated power,
and "annual use" is the average hours of operation per year. Emission factors are applied on a brake-
specific basis (g/kW-hr) and represent the weighted value between levels from baseline and
controlled marine engines operating in a given calendar year. Emission inventories from Category
1 engines were calculated for HC, NOx, CO, and PM. Although the proposed standards combine
HC and NOx, it is useful to consider the HC and NOx emission impacts separately. The split
between HC and NOx for regulated engines is based on the data from Chapter 3 for technologies that
are expected to be used to meet the proposed standards.
2. Inputs to the Inventory Calculations
Data on the various inputs were obtained from several sources. Engine populations were taken
from the 1997 Power Systems Research (PSR) Parts Link database. This database contains marine
engine populations and technical information by engine model for 1990 through 1997. From this
data, EPA was able to focus on specific applications and power ranges. To determine turnover rates
for the purpose of determining the introduction of controlled engines, scrappage rates are needed.
Through the combination of historical population and scrappage rates, historical sales and retirement
of engines can be estimated. EPA used the normalized scrappage rate developed by PSR and fit it
to the data using assumed average useful lives for each of the three applications. Figure 5-1 presents
the normalized scrappage curve. The average useful lives for each of the three applications were
based on conversations with manufacturers and are estimated to be 15,13, and 17 years respectively
for recreational, commercial, and auxiliary marine diesel engines.
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Regulatory Impact Analysis
Figure 5-1: Normalized Scrappage Curve
0 0.5 1 1.5 2
Engine Age Normalized by Average Useful Life
To project future populations, EPA applied growth rates to each of the three application types.
Based on the eight years of population data (1990-1997) supplied by the PSR Parts Link database,
growth rates of 6.3 percent for recreational, 0.6 percent for commercial, and 7.5 percent for auxiliary
were observed. EPA was concerned that eight years of data were not enough to determine a
historical growth trend, especially since the growth rates for these years were so high for recreational
and auxiliary marine engines. To estimate growth over a larger number of years, EPA relied on
PSR's OE Link database which provides detailed information on the U.S. production of marine
diesel engines from 1980 to 1997. Based on the PSR production data, EPA calculated growth rates
of 3.5 percent for recreational, 0.9 percent for commercial, and 1.5 percent for auxiliary marine
diesel engines. In its final calculations, EPA used the growth rates based on U.S. production.
Although the growth rate for recreational marine diesel engines is significantly larger than for
commercial and auxiliary, EPA believes that it is reasonable due to recently expanded efforts of
marine diesel engine manufacturers to break into this potentially high profit market.
Estimated engine populations are presented in Table 5-1. These figures show that recreational
marine engines are the largest segment of the U.S. Category 1 marine diesel engine population. As
will be shown below, however, their inventory contribution is much less than theat of the smaller
commercial population due to different usage rates.
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Chapter 5: Environmental Impacts
Table 5-1
Projected Category 1 Populations by Year [thousands]
recreational
commercial
auxiliary
1995
142
57
10
2000
180
58
13
2005
214
61
14
2010
254
64
15
2020
358
70
17
2030
505
76
20
The remaining factors needed to estimate the category 1 emissions inventory are engine usage
and emission rates. Recreational and commercial marine diesel engine usage characteristics are
based on a compilation of data supplied to the EPA by the Engine Manufacturers Association
(EMA). This data is based on five years of propulsion marine diesel engine sales from seven engine
manufacturers who make up the strong maj ority of the U. S. market.d Included in the data submission
were average annual hours of use, load factors, and emission factors broken down by ranges of rated
power and rated speed. Because the submission did not include auxiliary marine engines,
conversations with individual manufacturers were used to develop usage inputs for these engines.
Baseline emission factors were developed using the both the EMA submission and the data for
uncontrolled marine diesel engines presented in Chapter 3. The usage inputs and baseline emission
factors, used in the inventory calculations, are presented in Tables 5-2 and 5-3.
Table 5-2
Usage Inputs for Category 1 Inventory Calculations
Power
lange [kW]
37-75
75-130
130-225
225-450
450-560
560+
Load Factor [percent]
recreational
25
25
25
30
40
40
commercial
60
60
60
71
73
79
auxiliary
65
65
65
65
65
65
Annual Use [hours
recreational
125
175
175
225
500
500
commercial
2320
2350
2270
3240
3770
4500
auxiliary
2500
2500
2500
2500
2500
2500
d Although difficult to compare directly, these sales figures seemed to agree with the PSR
data fairly well.
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Regulatory Impact Analysis
Table 5-3
Baseline Emission Factors for Category 1 Marine Engines
Power Range
[kW]
37-75
75-130
130-225
225-450
450-560
560-1000
1000+
HC
[g/kW-hr]
0.27
0.27
0.27
0.27
0.27
0.27
0.27
NOx
[g/kW-hr]
11
10
10
10
10
10
13
CO
[g/kW-hr]
2.0
1.7
1.5
1.5
1.5
1.5
2.5
PM
[g/kW-hr]
0.90
0.40
0.40
0.30
0.30
0.30
0.30
The proposed emission standards, presented in Chapter 1, were used as the emission factors for
the controlled engines. Not enough information is available at this time to account for deterioration
or manufacturer compliance margins. EPA believes that these factors will not have a large effect
on the final calculations. At worst, this methodology results in conservative benefit estimates since
the standards represent levels at the useful lives of the engines. In the proposed program, HC and
NOx are combined in a single numerical emission limit. To separate them for inventory analysis,
EPA estimates that the proposed emissions limits will result in a 0.07 g/kW-hr reduction in HC.
This estimate is based on the emission data from the low-emission engines presented in Chapter 3.
3. Inventory Results
Table 5-4 presents the estimated baseline emissions for recreational, commercial, and auxiliary
marine engines. Although no standards have been proposed for recreational marine engines at this
time, they are included in this analysis for completeness.
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Chapter 5: Environmental Impacts
Table 5-4
Projected Category 1 Baseline Emissions by Year [thousand short tons]
HC
NOx
PM
CO
recreational
commercial
auxiliary
total
recreational
commercial
auxiliary
total
recreational
commercial
auxiliary
total
recreational
commercial
auxiliary
total
1995
0.6
9.9
0.7
11.3
21.9
382
28.3
432
0.7
12.0
1.1
13.9
3.4
60.2
4.5
68.0
2000
0.8
10.3
1.0
12.1
29.7
398
38.0
465
1.0
12.5
1.5
14.9
4.7
62.8
6.0
73.4
2005
0.9
10.8
1.1
12.8
35.3
416
40.9
492
1.1
13.1
1.6
15.8
5.5
65.6
6.4
77.6
2010
1.1
11.3
1.2
13.6
42.0
435
44.1
521
1.4
13.7
1.7
16.8
6.6
68.6
6.9
82.1
2020
1.6
12.4
1.4
15.3
59.2
476
51.1
586
1.9
14.9
2.0
18.9
9.3
75.1
8.0
92.4
2030
2.2
13.5
1.6
17.3
83.5
520
59.3
663
2.7
16.3
2.3
21.4
13.1
82.1
9.3
105
This analysis suggests that commercial marine engines make up the majority of the Category
1 emissions (i.e. 85 percent of HC+NOx in 2000) even though they made up only 23 percent of the
population of Category 1 engines in 2000. This is mostly due to the high annual use and load factors
of these engines. By comparison, recreational engines represent 72 percent of the population in
2000, but account for only 6 percent of baseline Category 1 HC+NOx emissions. However, due to
their higher projected growth rate, recreational engines become a growing source of marine diesel
emissions in future years (10 percent of the baseline in 2020).
4. Emissions Benefits
Tables 5-5 and 5-6 show the expected impact of the proposed standards on HC, NOx, and PM
emissions from commercial and auxiliary Category 1 marine diesel engines. For the applicable
Category 1 engines, the proposed Tier 2 standards represent average reductions of 27 percent HC,
29 percent NOx, and 38 percent PM on a per engine basis. The proposed Tier 3 standards gain
105
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Regulatory Impact Analysis
additional NOx benefits which represent a total reduction of 62 percent NOx from applicable new
engines compared to baseline. These reductions vary for different power categories with the highest
power categories showing the greatest reductions. This is reasonable since these engines are used
more intensely than the others. It should be noted that for the cost-effectiveness calculations in
Chapter 6, only the NOx reductions beyond the EVIO standard are considered. For Category 1, the
EVIO standard represents a 3.5 percent reduction in NOx from new engines compared to baseline.
The CO standard is intended to be a cap on the already low emissions from diesel engines; therefore,
no emissions reductions are claimed here for CO.
Table 5-5
Projected Controlled Category 1
Commercial Marine Engine Emissions [thousand short tons per year]
Modeled Item
HC
NOx
PM
controlled level
benefit
reduction
controlled level
benefit
reduction
controlled level
benefit
reduction
1995
9.9
0.0
0%
382
0.0
0%
12.0
0.0
0%
2000
10.3
0.0
0%
396
1.2
0%
12.5
0.0
0%
2005
10.5
0.3
3%
396
20.4
5%
12.5
0.6
4%
2010
10.0
1.3
12%
341
93.7
22%
11.3
2.3
17%
2020
9.4
3.0
24%
217
258
54%
9.8
5.2
35%
2030
10.0
3.5
26%
203
316
61%
10.3
6.0
37%
106
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Chapter 5: Environmental Impacts
Table 5-6
Projected Controlled Category 1
Auxiliary Marine Engine Emissions [thousand short tons per year]
Modeled Item
HC
NOx
PM
controlled level
benefit
reduction
controlled level
benefit
reduction
controlled level
benefit
reduction
1995
0.7
0.0
0%
28.3
0.0
0%
1.1
0.0
0%
2000
1.0
0.0
0%
37.9
0.1
0%
1.5
0.0
0%
2005
1.1
0.0
3%
39.3
1.6
4%
1.5
0.1
5%
2010
1.1
0.1
10%
36.4
7.6
17%
1.5
0.3
16%
2020
1.1
0.3
22%
26.7
24.4
48%
1.3
0.7
36%
2030
1.2
0.4
25%
23.5
35.8
60%
1.4
1.0
41%
As described in the notice of proposed rulemaking, EPA intends to require that manufacturers
comply with emission limits at any speed and load that can occur on a vessel. These "not-to-exceed"
provisions are needed to keep pace with the increasing sophistication of diesel engine technology.
These provisions are intended to ensure that engines are in fact operating within allowable emission
levels, rather than requiring emission reductions beyond that called for by the emission limits. This
analysis of emission benefits thus does not take into account any additional benefit associated with
not-to-exceed provisions.
Figure 5-2 presents EPA projections for Category 1 HC, NOx, PM, and CO emissions as a
whole. The graphs included in this figure show baseline emissions as well as the expected control
under the proposed standards. The NOx proj ection distinguishes the slight benefits associated with
the EVIO NOx standard from the benefits associated with this proposal. In 2010, the proposed
standards are expected to result in reductions of 11 percent HC, 20 percent NOx, and 16 percent PM
from Category 1 marine diesel engines. Once the effects of the proposed standards are fully phased
in (i.e. in 2035 the proposed emission levels would result in reductions of 23 percent HC, 58 percent
NOx, and 33 percent PM from Category 1 marine diesel engines. These figures are lower than the
per engine reductions because they do not include any potential future emissions reductions from
recreational marine diesel engines.
107
-------
Figure 5-2: Projected Baseline and Controlled Emissions Levels from Category 1 Marine Diesel Engines
20
15
c
£
£ o
10
Hydrocarbons
~ Baseline
™ Controlled
2000 2010 2020
Calendar Year
2030
Particulate Matter
— Baseline
~ Controlled
2000 2010 2020
Calendar Year
2030
Oxides of Nitrogen
-~ Baseline
— IMO
• Controlled
2000 2010 2020
Calendar Year
2030
Carbon Monoxide
-~ Baseline
~ Controlled
2000 2010 2020
Calendar Year
2030
-------
Chapter 5: Environmental Impacts
B. Category!
1. Baseline Emission Inventories
Baseline emissions inventories for Category 2 marine diesel engines are based on an analysis
developed by Corbett and Fischbeck.1 In that analysis, two separate methods were used to develop
inventories for U.S. flagged vessels and foreign vessels used in U.S. domestic waters. In addition,
the study investigated marine engine types and replacement rates. Below is an overview of the
analysis; more detail may be found in the report.
Emissions inventories for U.S. flagged vessels were estimated using ship registry data on
commercial vessels greater than 100 gross registered tons. The general methodology is based on
estimates of daily fuel consumption. Specifically, engine rated power, operation, fuel consumption
and fuel specific emissions factors, developed by Lloyd's Register, were used to generate annual
mass of emissions from a given vessel. These emission numbers were multiplied by the number of
U.S. flagged vessels for discrete applications to generate a baseline emission inventory for domestic
ships.
Estimated emissions inventories for foreign ships operating in U. S. navigable waters were based
on cargo movements and waterways data. Using cargo movements and geographical data, the ton-
miles of cargo moved in each region were calculated for the Great Lakes, inland waterways, and
coastal waters up to 200 miles offshore. Emissions per ton mile were based on the usage and
emission factors used for U.S. vessels described above, average dead weight tonnage per ship,
assumed cargo capacity factors, and average vessel speed for the duty cycle. The results from this
analysis are presented in Table 5-7.
Table 5-7
Baseline Emissions from Category 2 CI Marine
Engines Operated in U.S. Waters [thousand short tons per year]
Year
2000
2010
2020
2030
2040
HC
11.1
12.3
13.6
15.0
16.5
NOx
267
295
325
360
397
PM
6.1
6.8
7.5
8.3
9.1
CO
34.1
37.7
41.7
46.0
50.8
2. Emission Benefits
To calculate the emissions benefits of the proposed standards, the replacement rates of old
engines with new engines must be known. For this analysis, the average useful life of 23 years
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Regulatory Impact Analysis
reported in the report by Corbett and Fischbeck was used. This report also discusses a growth rate
of 2 percent based on production and turnover in recent years. However, EPA was concerned that
a few years of data was not enough to establish a growth trend for this industry. Therefore, EPA
conservatively is using a growth rate of 1 percent which is more consistent with the Category 1
growth rates used in this analysis. By combining the 23 year average useful life with the normalized
scrappage curve presented in Figure 5-1 and the estimated growth rate, EPA developed the
replacement schedule used for the inventory analysis. Because of the high average age of the U.S.
fleet, EPA believes that it is likely that their will be higher turnover than usual in the near future.
This would result in greater benefits sooner. However, EPA has not made any attempts to include
this dynamic in its inventory analysis.
Emissions reductions were based on the baseline brake-specific emission levels presented in
Chapter 3 and the proposed standards presented in Chapter 1. Since EPA is only claiming NOx
reductions from the proposed standards beyond those resulting from the EVIO standards, the EVIO
reduction was calculated. The EVIO standard will result in an average reduction of 15 percent from
new engines compared to baseline engines. On a per engine basis, the proposed Tier 2 standards
represent reductions of 47 percent NOx, 16 percent PM, and 19 percent CO compared to baseline
Category 2 emissions levels. The proposed Tier 3 standards result in a total reduction in NOx of
64 percent compared to baseline. In the benefits modeling described here, these reductions are only
applied to engines in U.S. flagged vessels operated in U.S. waters. No HC benefits are claimed for
Category 2 engines due to their already low HC emissions. Because of the slow turnover rates, the
full effects of these reductions would not be seen until after 2045. Projected benefits of the EVIO
requirements and the proposed standards for Category 2 engines are shown in Table 5-8. No NOx
reductions are assumed for foreign flagged ships since it is unknown at this time which countries will
adopt the EVIO requirements. Foreign flagged ships make up about 4 percent of the Category 2 NOx
inventory in U.S. waters.
Table 5-8
Projected Emission Reductions from Category 2
CI Marine Engines Operated in U.S. Waters [thousand short tons]
Year
2000
2010
2020
2030
2040
EVTONOx
1.6
19.2
38.3
50.5
58.1
EPA NOx
0.0
20.2
81.3
142
177
PM
0.0
0.2
0.6
1.0
1.2
CO
0.0
1.4
4.6
9.3
10.5
110
-------
Figure 5-3: Projected Baseline and Controlled Levels for Category 2 Marine Diesel Engines
Hydrocarbons
~~ Baseline
~ Controlled
2010 2020 2030
Calendar Year
2040
12
10
8
, — , CO
(0 T3
lie
s g
"- 4
2
0
20
Particulate Matter
—
^^^
,—^
. ^^__
^^ "
•—
— Baseline
™ Controlled
00 2010 2020 2030 2040
Calendar Year
500
Oxides of Nitrogen
~ Baseline
— IMO
™ Controlled
2000 2010 2020 2030
Calendar Year
2040
Carbon Monoxide
— Baseline
™ Controlled
2000 2010 2020 2030
Calendar Year
2040
-------
Regulatory Impact Analysis
As described for Category 1 engines above, this calculation of emission benefits for Category
2 engines does not take into account any additional benefits for not-to-exceed provisions.
Figure 5-3 presents EPA projections for Category 2 HC, NOx, PM, and CO emissions. The
graphs included in this figure show baseline emissions as well as the expected control under the
proposed standards. The NOx projection shows the fraction of the total benefits which can be
attributed to the EVIO NOx standard. Because engines on foreign flag vessels are not included in the
proposed regulations, the percent reductions from engines on vessels operating in U.S. waters is not
as high as the percent reductions for new engines. The HC standard is intended to be a cap on the
already low emissions from Category 2 diesel engines; therefore, no emissions reductions are
claimed here for HC.
C. Category 3
1. Baseline Emissions
Baseline emissions were calculated for Category 3 using the same methodology that was used
for Category 2. The difference between Category 2 and 3 is that foreign vessels only make a small
fraction of the national NOx for Category 2, while they make up about half of the national NOx for
Category 3. This difference is easily explained by the fact that most Category 3 engines are used on
ocean-going vessels, and while U. S. is a large foreign trade country, most of the ocean-going vessels
that visit U.S. ports are foreign flag. Baseline emission results from the Category 3 inventory
calculations are presented in Table 5-9.
Table 5-9
Baseline Emissions from Category 3 CI Marine
Engines Operated in U.S. Waters [thousand short tons per year]
Year
2000
2010
2020
2030
2040
HC
8.1
9.0
9.9
10.9
12.1
NOx
273
301
333
368
406
PM
21.2
23.4
25.8
28.6
31.5
CO
25.0
27.6
30.5
33.7
37.2
2. Emission Benefits
This section calculates the emissions benefits for Category 3 engines associated with adopting
the EVIO requirements for Category 3 engines on U.S. flagged ships. Emissions benefits were
calculated using the same useful life and growth rate used for in the Category 2 analysis based on
112
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Chapter 5: Environmental Impacts
the limited data available to EPA. NOx reductions were determined by comparing the data in
Chapter 3 to the proposed emission limits presented in Chapter 1. As discussed in Chapter 3, it was
assumed that engines that certify on diesel oil but operate on residual fuel would have 10 percent
higher NOx emissions in use.
EPA estimates that adopting the EVIO requirements will result in a 17 percent reduction in NOx
from applicable new Category 3 engines. If this standard were only met on U.S. flagged ships, only
about a 9 percent reduction in NOx is anticipated once all U.S. flag ships meet the EVIO NOx
standard. However, foreign flag ships may reduce NOx as other nations adopt the EVIO provisions.
The U.S. flag reductions and the potential effects (in U.S. waters) of world wide application of the
EVIO NOx standard are both presented in Table 5-10 and Figure 5-4.
Table 5-10
Projected NOx Reductions from Category 3
CI Marine Engines Operated in U.S. Waters [thousand short tons]
2000
2010
2020
2030
2040
U.S. Flag
1.0
11.4
22.7
29.8
34.3
Foreign Flag*
0.9
11.2
22.3
29.4
33.8
Total*
1.9
22.5
45.0
59.2
68.1
* The U.S. could only ensure that the reductions from U.S. flagged ships are achieved.
113
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Regulatory Impact Analysis
Figure 5-4: Projected Baseline and Controlled National NOx Emissions from
Category 3
500
400
300
id CO
1—'
-------
Chapter 5: Environmental Impacts
Figure 5-5: 2020 Baseline CI Marine NOx Inventory Distribution
Cat. 1 recreational
4.8%
Category 3
26.8%
Cat. 1 auxiliary
4.1%
Cat. 1 commercial
38.2%
Category 2
26.2%
Figure 5-6: 2020 Controlled CI Marine NOx Inventory Distribution
Benefit
33.8%
Cat. 1 recreational
4.8%
Category 3
24.9%
Cat. 1 auxiliary
2.2%
Cat. 1 commercial
17.7%
Category 2
16.6%
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Regulatory Impact Analysis
EPA used nationwide emission estimates from the 1997 Trends Report2 to compare the relative
emissions contribution from CI marine engines to other emission sources. Because Trends does not
report estimates for 1998, figures for 2000 are used here as the baseline. The national HC, NOx,
PM, and CO emissions inventories are summarized in Table 5-11 along with the EPA estimates for
CI marine engines. These data, presented in Table 5-10, indicate that emissions from baseline CI
marine engines account for 8.1 percent of NOx and 4.8 percent of PM from mobile sources and 4.4
percent of NOx and 1.0 percent of PM nationwide. CI marine engines account for less than one
percent of volatile organic sources (VOC) or CO for mobile sources.
Table 5-11
2000 National Emissions [thousand short tons]
Emission Source
CI Marine
Other Nonroad
On-Highway
Total Mobile Sources
Other Sources
Total Nationwide Emissions
VOC
31
2,044
4,482
6,526
9,567
16,093
NOx
1,005
4,930
6,397
12,332
10,550
22,882
PM
42
593
238
873
3,270*
4,143
CO
133
16,286
44,244
60,663
19,199
79,862
*does not include erosion or fugitive dust.
Table 5-12 contains the baseline annual emissions from marine diesel engines as a whole as well
as projections of the annual emissions with the EVIO requirements and proposed standards in place.
Figure 5-7 presents the NOx reductions graphically. According to this analysis, the proposed
standards would result in reductions, beyond the EVIO ratification, of 9 percent HC, 28 percent NOx,
12 percent PM, and 3 percent CO from marine diesel engines in 2020.
Nationally, the proposed standards would result in reductions of 1.3 percent NOx and 0.1
percent PM. The percent reduction would be much higher for port areas. This is especially true for
Los Angeles-South Coast, Baton Rouge, Beaumont-Port Arthur, and similar ports where marine
diesel engines account for a large fraction of the NOx emissions.
116
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Chapter 5: Environmental Impacts
Table 5-12
Total Emissions Reductions from the Proposed Rule
HC
103 short tons
NOx
103 short tons
PM
103 short tons
CO
103 short tons
baseline
controlled
reduction
baseline
IMO
controlled
reduction
baseline
controlled
reduction
baseline
controlled
reduction
2000
31.3
31.3
0%
1,005
1,001
1,001
0%
423.
42.3
0%
133
133
0%
2010
34.8
33.3
4%
1,117
1,072
965
10%
46.9
44.1
6%
147
146
1%
2020
38.7
35.4
9%
1,244
1,162
819
28%
52.2
45.7
12%
165
160
3%
2030
43.2
39.3
9%
1,390
1,287
815
34%
58.2
50.2
14%
184
177
4%
Figure 5-7: Projected National CI Marine Baseline and Controlled NOx Emissions
1400
1200
«T % 100°
~ £ 800
x ^
z jE 600
400
200
2000
2010 2020
Calendar Year
Baseline
IMO
Controlled
2030
117
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Regulatory Impact Analysis
E. Other Impacts of NOx Emission Reductions
The NOx reductions described above are expected to provide reductions in the concentrations
of secondary nitrate particulates. NOx can react with ammonia in the atmosphere to form
ammonium nitrate particulates, especially when ambient sulfur levels are relatively low. EPA
believes that the best estimate of atmospheric NOx to PM conversion rates available at this time is
provided by SAL3 SAI used a combination of ambient concentration data and computer modeling
that simulates atmospheric conditions to estimate to estimate the conversion of NOx to PM nitrate.
Ambient data was collected from 72 ozone, 64 NOx, and 14 NOMC monitoring sites for use in
oxidation calculations. Data was also collected from 45 nitrate/NOx monitoring sites for use in the
equilibrium calculations. For the purpose of modeling, the 48 continental states were divided into
nine regions, and rural areas were distinguished from urban areas. The model was designed to
perform the equilibrium calculation to estimate particulate nitrate formation for different regions,
seasons, and times of day and then was calibrated using ambient data.
The results from the SAI report state that the fraction of NOx converted to nitrates (g/g) ranges
from 0.01 in the northeast to 0.07 in southern California. Using a simple average, the average
fraction of NOx converted to nitrates is approximately 0.04. The effects of the conversion fraction
of future PM reductions are shown in Table 5-13.
Table 5-13
Equivalent PM Emissions for
CI Marine Engines [thousand short tons per year]
Year
2005
2010
2015
2020
Total NOx Reductions
38
152
298
425
Equivalent PM Reductions
1.5
6.1
11.9
17.0
The expected reductions in NOx emissions should also positively affect visibility, acid
deposition, and estuary eutrophication. Both NO2 and nitrate particulates are optically active, and
in some urban areas, NO2 and nitrate particulates can be responsible for 20 to 40 percent of the
visible light extinction. The effect of this proposed action on visibility should be small but
potentially significant, given that it is expected to reduce national NOx emissions by about 1.5
percent in 2020. This would result in a 0.3 to 0.6 percent reduction in haze. For areas with active
ports, this reduction would be significantly higher.
The NOx control described above is also expected to provide benefits with respect to acid
deposition. The annual NOx reduction expected in 2020 from the proposed standards for marine
diesel engines is comparable to the 400,000 ton per year reduction expected from Phase I of the
118
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Chapter 5: Environmental Impacts
Agency's acid rain NOx control rule (59 FR 13538, March 22, 1994), which was considered to be
a significant step toward controlling the ecological damage caused by acid deposition. It is not clear
how reductions from marine engines will compare to reductions from stationary sources with
elevated stacks; however, some reduction in the adverse effects of acid depositions should occur as
a result of this proposed rule.
This proposed action should also lead to a reduction in the nitrogen loading of estuaries. This
is significant since high nitrogen loadings can lead to eutrophication of the estuary, which causes
disruption in the ecological balance. The effect should be most significant in areas heavily affected
by atmospheric NOx emissions. One such estuary is Chesapeake Bay, where as much as 40 percent
of the nitrogen loading may be caused by atmospheric deposition. Also, marine engine emissions
by definition occur in the marine environment; therefore, reductions in exhaust emissions from
marine engines are expected to benefit the marine environment.
F. Air Toxics
The term "hydrocarbons" includes many different molecules. Speciation of the hydrocarbons
would show that many of the molecules are those which are considered to be air toxics including
benzene, formaldehyde, acetaldehyde, and 1,3-butadiene. Because EPA does not have speciated data
on diesel marine engine hydrocarbon emissions, the reductions in air toxics can only be estimated
here. This analysis was done using data on on-highway heavy-duty diesel engines.4'5'6'7 According
to this data, hydrocarbons from an on-highway HDDE include approximately 1.1 percent benzene,
7.8 percent formaldehyde, 2.9 percent acetaldehyde, and 0.6 percent 1,3-butadiene. Table 5-14
shows the estimated air toxics reductions associated with the hydrocarbon reductions in this rule
when the on-highway HDDE results are extended to this source.
Table 5-14
Estimated Annual Air Toxics Reductions [short tons]
Year
2005
2010
2015
2020
Benzene
4
15
35
41
Formaldehyde
26
114
258
305
Acetaldehyde
10
42
95
112
1,3 -Butadiene
2
9
20
24
119
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Regulatory Impact Analysis
Chapter 5 References
1. Corbett, J., Fischbeck, P., "Commercial Marine Emissions Inventory and Analysis for United
States Continental and Inland Waterways," Order No. 8A-0516-NATX, August 21, 1998.
2. "National Air Pollutant Emission Trends, 1900-1996," U.S. EPA, EPA-454/R-97-011,
December 1997.
3. "Benefits of Mobile Source NOx Related Particulate Matter Reductions," Systems
Applications International, EPA Contract No. 68-C5-0010, WAN 1-8, October 1996.
4. Springer, K., "Investigation of Diesel-Powered Vehicle Emissions VII," U.S. EPA, EPA-
460/3-76-034, 1977.
5. Springer, K., "Characterization of Sulfates, Odor, Smoke, POM and Particulates from Light
and Heavy-Duty Engines - Part IX," U.S. EPA, EPA-460/3-79-007, 1979.
6. Bass, E., and Newkirk, M., "Reactivity Comparison of Exhaust Emissions from Heavy-Duty
Engines Operating on Gasoline, Diesel, and Alternative Fuels," Southwest Research Institute,
SwRI9856, 1995.
7. College of Engineering - Center for Environmental Research and Technology, "Evaluation of
Factors that Affect Diesel Exhaust Toxicity," submitted to California Air Resources Board,
Contract No. 94-312, 1998.
120
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Chapter 6: Cost-Effectiveness
CHAPTER 6: COST-EFFECTIVENESS
This chapter assesses the cost-effectiveness of the proposed hydrocarbon and oxides of nitrogen
emission standards for marine diesel engines. This analysis relies in part on cost information from
Chapter 4 and emissions information from Chapter 5 to estimate the cost-effectiveness of the
proposed standards in terms of dollars per short ton of total HC+NOx emission reductions. This
chapter also examines the cost-effectiveness of the proposed PM standards. Finally, the chapter
compares the cost-effectiveness of the proposed provisions with the cost-effectiveness of other NOx
and PM control strategies from previous EPA rules.
The analysis presented in this chapter is performed for marine diesel engines and vessels using
the same nominal power ratings as presented in Chapter 4. An estimate of the industry-wide cost-
effectiveness of the proposed standards, combining all of the nominal engine sizes, is also presented.
Benefits associated with the EVIO provisions are not included in this analysis. Marine diesel
engines greater than or equal to 13 0 kW will be subj ect to an international NOx standard prior to the
implementation of the standards proposed under this rule. Therefore, the baseline emissions case
assumes emission control to the EVIO standard for engines installed on vessels in 2000 and later.
Because the proposed EPA standards only apply to Category 1 and 2, no cost-effectiveness analysis
is provided for Category 3.
Two types of cost-benefit analyses are performed in this chapter. The first analysis focuses on
individual engines and examines total costs and total emission reductions over the typical lifetime
of an average marine diesel engine discounted to the beginning of the engine's life. This analysis
is provided for the proposed Tier 2 and for the incremental costs and benefits associated with the
proposed Tier 3 standards. The second method looks at the net present value (NPV) of a stream of
costs and benefits over a standardized period of time (30 years). Over this period, the calculation
includes the proposed program as a whole.
As described in Chapter 4, several of the anticipated engine technologies will result in
improvements in engine performance that go beyond emission control. While the cost estimates
described in Chapter 4 do not take into account the observed value of performance improvements,
these non-emission benefits should be taken into account in the calculation of cost-effectiveness.
EPA believes that an equal weighting of emission and non-emission benefits is justified for those
technologies which clearly have substantial non-emission benefits, namely electronic controls, fuel
injection changes, turbocharging, and engine modifications. For some or all of these technologies,
a greater value for the non-emission benefits could likely be justified. This has the effect of halving
the cost for those technologies in the cost-effectiveness calculation. The cost-effectiveness values
in this chapter are based on this calculation methodology. Table 6-2 provides a side-by-side
comparison of cost-effectiveness values with and without accounting for the non-emission benefits.
Cost-effectiveness figures in other tables in this chapter are presented taking the non-emission
121
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Regulatory Impact Analysis
benefits into account and would therefore need to be adjusted similarly to exclude non-emission
benefits from the calculation.
I. Engine Lifetime Cost-Effectiveness of the Proposed Standards
A. HC+NOx
The cost-effectiveness of the proposed HC+NOx standards was calculated for the various
nominal marine engine power ratings described in Chapter 4. For this analysis, the entire cost of the
proposed program is attributed to the control of HC and NOx emissions. As discussed in Chapter
4, the estimated cost of complying with the proposed standards varies depending on the model year
under consideration (i.e. year 1 versus year 6 for Tier 3). Therefore, this analysis includes the per-
engine cost-effectiveness results for the different model years during which the costs are expected
to change. This analysis focuses on costs and benefits for individual engine types; therefore, the
costs presented in this section represent the actual cost-effectiveness as it affects a given engine. All
of the costs and benefits are discounted at seven percent to the model year of the marine engine.
1. Tier 2
EPA calculated the costs and benefits for Tier 2 and Tier 3 separately. Tier 2 benefits are those
achieved from the proposed Tier 2 standards beyond the EVIO requirements. Tier 2 costs are
compared to baseline technology. EPA conservatively did not make an attempt to estimate costs for
any development work or new technology that could be attributed to the EVIO requirements and,
therefore, removed from this analysis. Table 6-1 presents the Tier 2 discounted cost-effectiveness
for marine diesel engines at the five nominal marine power ratings.
Table 6-1
Discounted Cost-Effectiveness ($/short ton) of the Proposed
Tier 2 HC+NOx Standards for Marine Diesel Engines with Nominal Power Ratings
Nominal Power
(kW)
100
400
750
1500
3000
Engine & Vessel
Costs
$1,570
$2,452
$22,610
$20,068
$41,539
Operating &
Compliance
NPV Costs
$368
$564
$103
$318
$6,215
NPV Benefits
(short tons)
4.3
26
80
267
829
Discounted
Cost-
Effectiveness
$449
$116
$283
$76
$58
122
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Chapter 6: Cost-Effectiveness
Table 6-2
Comparison of Cost-Effectiveness Methodologies for Tier 2
Nominal Power
100
400
750
1500
3000
Not Accounting for Non-emission
Benefits
Incremental
Purchase Price
$2,577
$4,249
$25,319
$22,725
$54,103
Discounted Cost-
Effectiveness
$738
$201
$317
$5
$76
Accounting for Non-emission
Benefits
Incremental
Purchase Price
$1,570
$2,452
$22,610
$20,068
$41,539
Discounted Cost-
Effectiveness
$449
$116
$283
$4
$58
Category 1, Category 2, and aggregate marine diesel engine cost-effectiveness figures for the
proposed Tier 2 HC+NOx standards were also calculated. To accomplish this, each nominal power
rating was assumed to represent a range of engine power ratings. Each of the ratings was then
weighted using 1997 marine engine populations. Table 6-3 shows how the nominal power ratings
were applied to the population as a whole.
Table 6-3
1997 Marine Diesel Engine Populations by Power Category
Category
Category 1
Category 2
Nominal Power (kW)
100
400
750
1500
3000
Power Range (kW)
37 - 225
225 - 560
560 - 1000
1000 +
all
Population
42,700
23,700
2,400
2,600
1,600
Table 6-4 presents the Tier 2 aggregate cost-effectiveness for Category 1 and 2 both individually
and combined. Population weighted costs and were divided by the population weighted discounted
benefits to determine the aggregate cost-effectiveness figures. These figures suggest that the
proposed Tier 2 standards for HC+NOx from marine diesel engines are very cost-effective. This
result is largely due to the high hours of operation performed annually by these engines and their
long useful lives.
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Regulatory Impact Analysis
Table 6-4
Discounted Cost-Effectiveness ($/shortton) of the
Proposed Tier 2 HC+NOx Standards for Category 1 and 2 Marine Diesel Engines
Category 1
Category 2
Combined
Engine & Vessel
Costs
$3,247
$41,539
$4,070
Operating &
Compliance
NPV Costs
$422
$6,215
$547
NPV Benefits
(short tons)
24
829
41
Discounted
Cost-
Effectiveness
$156
$58
$113
2. TierS
Tier 3 cost-effectiveness was separated from the Tier 2 cost-effectiveness so that both of the
proposed standards could be investigated separately. This is important because of the long lead time
associated with the proposed Tier 3 standards and the anticipated feasibility review. Although the
cost and benefits associated with Tier 3 will probably change as part of the feasibility review, this
analysis gives EPA's best estimate of cost-effectiveness of the proposed Tier 3 HC+NOx standards
based on incremental costs and benefits beyond the proposed Tier 2 HC+NOx standards. Table 6-5
presents the Tier 3 discounted incremental cost-effectiveness for marine diesel engines at the five
nominal marine power ratings.
124
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Chapter 6: Cost-Effectiveness
Table 6-5
Discounted Cost-Effectiveness ($/short ton) of the Proposed Tier 3
HC+NOx Standards for Marine Diesel Engines with Nominal Power Ratings
Nominal
Power (kW)
100
400
750
1500
3000
Model Year
Grouping
1 to 5
6 +
1 to 5
6 +
1 to 5
6 +
1 to 5
6 +
1 to 5
6 +
Engine &
Vessel
Costs
$4,353
$688
$5,149
$1,071
$22,365
$3,362
$21,761
$5,884
$34,649
$2,550
Operating &
Compliance
NPV Costs
$478
$655
$1,469
$2,518
$2,003
NPV Benefits
(short tons)
4.2
30
77
136
290
Discounted Cost-
Effectiveness
$1,155
$279
$196
$58
$308
$62
$178
$62
$127
$16
Table 6-6 presents the Tier 3 aggregate incremental cost-effectiveness for Category 1 and
Category 2, both individually and combined. These aggregate figures are determined using the
population estimates in Table 6-3. As with Tier 2, the additional costs and benefits associated with
the proposed Tier 3 standards for HC+NOx from marine diesel engines are very cost-effective.
125
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Regulatory Impact Analysis
Table 6-6
Discounted Cost-Effectiveness ($/short ton) of the Proposed
Tier 3 HC+NOx Standards for Category 1 and 2 Marine Diesel Engines
Category 1
Category 2
Combined
Model Year
Grouping
1 to 5
6 +
1 to 5
6 +
1 to 5
6 +
Engine &
Vessel
Costs
$5,859
$1,095
$34,649
$2,550
$6,478
$1,126
Operating &
Compliance
NPV Costs
$644
$2,003
$673
NPV Benefits
(short tons)
20
290
26
Discounted Cost-
Effectiveness
$327
$87
$127
$16
$278
$70
B. PM
EPA has also estimated the cost-effectiveness of the proposed PM emission standards for
marine diesel engines for each of the nominal power ratings. Because no additional reductions in
PM are proposed for Tier 3 at this time, the PM cost-effectiveness is calculated for Tier 2 only. The
per-engine PM emission reduction estimates were developed in Chapter 5. For costs, EPA assumed
that half of the increased engine and vessel costs projected in Chapter 4 were allocated for PM
control. Because the entire cost of the proposed program was included in the HC+NOx analysis, this
analysis for PM cost-effectiveness is only a supplement to the cost-effectiveness calculations. EPA
believes that this analysis is conservative given the stringency of the HC+NOx standards and results
in an upper end estimate of the cost-effectiveness of the proposed PM control. In addition it should
be noted that the HC+NOx cost-effectiveness calculations discussed above include the entire cost
of the engine modifications that EPA believes would result due to this proposed rule. Table 6-7
contains the resulting cost-effectiveness for each of the nominal power ratings.
126
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Chapter 6: Cost-Effectiveness
Table 6-1
Discounted Cost-Effectiveness ($/short ton) of the Proposed
PM Standards for Marine Diesel Engines with Nominal Power Ratings
Nominal
Power (kW)
100
400
750
1500
3000
Model Year
Grouping
1 to 5
6 +
1 to 5
6 +
1 to 5
6 +
1 to 5
6 +
1 to 5
6 +
Engine &
Vessel
Costs
$785
$194
$1,226
$318
$11,305
$42
$10,034
$130
$20,770
$3,159
Operating &
Compliance
NPV Costs
$184
$282
$52
$159
$3,108
NPV Benefits
(short tons)
0.13
0.93
2.87
6.20
6.58
Discounted Cost-
Effectiveness
$7,416
$2,892
$1,629
$648
$3,961
$33
$1,644
$47
$3,628
$952
Table 6-8 presents the aggregate of these numbers for Category 1 and 2 both separately and
together. This aggregation of the cost-effectiveness figures was performed in the same way as for
the HC+NOx cost-effectiveness analysis. The results of this analysis show low cost-effectiveness
numbers for PM control. These costs would probably also be considered low even if all of the
engine and vessel costs associated with this proposed rulemaking were applied to the PM cost-
effectiveness analysis.
127
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Regulatory Impact Analysis
Table 6-8
Discounted Cost-Effectiveness ($/shortton) of the
Proposed PM Standards for Category 1 and 2 Marine Diesel Engines
Category 1
Category 2
Combined
Model Year
Grouping
1 to 5
6 +
1 to 5
6 +
1 to 5
6 +
Engine &
Vessel
Costs
$1,623
$228
$20,770
$3,159
$2,035
$291
Operating &
Compliance
NPV Costs
$211
$3,108
$274
NPV Benefits
(short tons)
0.77
6.20
0.89
Discounted Cost-
Effectiveness
$2,396
$573
$3,852
$1,011
$2,592
$633
C. Comparison with Cost-Effectiveness of Other Control Programs
In an effort to evaluate the cost-effectiveness of the proposed standards, EPA has summarized
the cost-effectiveness results for four other recent EPA mobile source rulemakings that required
reductions in NOx emissions. Where HC+NOx cost-effectiveness was not reported, NOx cost-
effectiveness-figures are reported. NOx cost-effectiveness figures should be close to HC+NOx cost-
effectiveness figures since NOx is the primary focus of the proposed standards and because NOx
emissions are generally much higher than HC emissions for diesel engines. Table 6-9 summarizes
the cost-effectiveness results from the heavy-duty vehicle portion of the Clean Fuel Fleet Vehicle
Program, the most recent HC+NOx engine standards for highway heavy-duty diesel engines, and the
nonroad Tier 2 standards.
A comparison of the cost-effectiveness numbers in Table 6-9 with the cost-effectiveness results
presented throughout this chapter for marine diesel engines shows that the cost-effectiveness of the
proposed HC+NOx standards are more favorable than the cost-effectiveness results of any of these
recent rules. To be consistent with the cost-effectiveness values for other programs, the marine
diesel numbers shown in Tables 6-9 and 6-10 reflect the aggregate cost-effectiveness for the
program rather than the high and low for individual engines.
128
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Chapter 6: Cost-Effectiveness
Table 6-9
Summary of Cost-Effectiveness for Recent EPA NOx Control Programs
EPA Rule
Clean Fuel Fleet Vehicle Program
(Heavy-duty)
2.5 g/hp-hr NMHC*+NOx Standard for
Highway Heavy-Duty Engines
Locomotive Engine Standards
Nonroad Tier 2 Standards
Proposed Marine Diesel > 37kW
Standards
Pollutants Considered
in Calculations
NOx
NMHC*+NOx
NOx
NMHC*+NOx
HC+NOx
Cost-Effectiveness
($/ton)
$1,300 -$1,500
$100 - $600
$160 -$250
$480 - $540
$30 - $280
* nonmethane hydrocarbons (roughly equivalent to total HC for diesel engines)
For comparison purposes, EPA has also summarized the cost-effectiveness results for three
other recent EPA mobile source rulemakings that required reductions in PM emissions. Table 6-10
summarizes the cost-effectiveness results for the most recent urban bus engine PM standard and the
urban bus retrofit/rebuild program. The PM cost-effectiveness results presented earlier in Table 6-8
are more favorable than either of the urban bus programs and comparable to the nonroad Tier 2
standards.
Table 6-10
Summary of Cost-Effectiveness for Recent EPA PM Control Programs
EPA Rule
0.05 g/hp-hr Urban Bus PM Standard
Urban Bus Retrofit/Rebuild Program
Nonroad Tier 2 Standards
Proposed Marine Diesel >37kW Standards
Cost-Effectiveness ($/ton)
$10,000 -$16,000
$25,500
$700 - $2,320
$600 - $2,600
129
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Regulatory Impact Analysis
II. 30-Year Cost-Effectiveness of the Proposed Standards
Another tool that can be used to evaluate the cost-effectiveness of a regulatory program is to
look at the costs incurred and the emissions benefits achieved over a fixed period of time. The
standard period of time associated with this type of rulemaking is 30 years. In this analysis, the net
present value (NPV) of the costs incurred from 2000 to 2030 is divided by the NPV of the benefits
achieved over this same time period. NPV is calculated using a seven percent time value of money
and a seven percent time value of emission reductions. Because this analysis relies on the stream
of effects of the proposed rule over time, Tier 2 and Tier 3 are combined for a single cost-
effectiveness result. The streams of costs presented here are based on the cost figures developed in
Chapter 4. Non emission benefits are not accounted for here.
A. HC+NOx
Figure 6-11 presents the stream of costs and benefits associated with the proposed standards for
HC+NOx. The discounted cost-effectiveness of the proposed HC+NOx standards over a 30-year
period is $ 156/ton for Category 1, $5 I/ton for Category 2, and $ 13 I/ton for the aggregate. It should
be noted that these figures are a little higher than those presented above for year 6 on a per-engine
basis. This difference is because the per-engine analysis relates costs to their resulting benefits while
the stream of costs analysis compares costs incurred to benefits achieved in a fixed time frame. In
other words, many of the costs incurred prior to 2030 will not achieve benefits until after 2030. This
is, in part, due to the long lives and slow turnover of marine engines.
B. PM
Table 6-12 presents the stream of costs and benefits associated with the proposed standards for
PM. As with the per-engine analysis, EPA conservatively applied half of the incurred costs to PM
control. The discounted cost-effectiveness of the proposed HC+NOx standards over a 3 0-year period
is $3,243/ton for Category 1, $3,384/ton for Category 2, and $3,256/ton for the aggregate. The same
relationship exists for these PM cost-effectiveness figures compared to the per-engine PM cost-
effectiveness figures as does for the HC+NOx analysis.
130
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Chapter 6: Cost-Effectiveness
Table 6-11
30-Year Stream of Costs and Benefits for the Proposed HC+NOx Standards
Calendar
Year
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
NPV
Category 1
Costs (106 $)
$18.8
$19.0
$22.2
$22.4
$53.4
$38.8
$42.3
$39.3
$39.3
$15.9
$15.9
$13.9
$14.0
$14.0
$14.1
$14.1
$14.2
$14.2
$14.3
$14.4
$14.4
$14.5
$14.5
$14.6
$14.6
$14.7
$14.8
$14.9
$15.1
$15.2
$15.4
$292
Benefits (103 tons)
7.2
14.5
24.1
33.7
51.3
69.2
88.6
108
128
148
167
186
204
222
238
253
265
277
286
295
302
308
314
319
324
329
333
337
340
343
347
1,864
Category 2
Costs (106 $)
$0
$0
$3.8
$3.8
$3.8
$3.9
$7.0
$3.9
$3.9
$4.0
$4.0
$1.2
$1.2
$1.2
$1.2
$1.2
$1.2
$1.2
$1.2
$1.3
$1.3
$1.3
$1.3
$1.3
$1.3
$1.3
$1.3
$1.3
$1.4
$1.4
$1.4
$30.2
Benefits (103 tons)
0
0
3.5
7.1
10.8
14.5
20.2
26.0
31.9
37.8
43.8
49.9
56.1
62.3
68.6
74.9
81.3
87.7
94.1
101
107
114
120
126
132
137
142
147
151
155
159
590
131
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Regulatory Impact Analysis
Table 6-12
30-Year Stream of Costs and Benefits for the Proposed PM Standards
Calendar
Year
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
NPV
Category 1
Costs (106 $)
$9.4
$9.5
$11.1
$11.2
$26.7
$19.4
$21.1
$19.6
$19.7
$7.9
$8.0
$7.0
$7.0
$7.0
$7.0
$7.1
$7.1
$7.1
$7.1
$7.2
$7.2
$7.2
$7.3
$7.3
$7.3
$7.3
$7.4
$7.5
$7.5
$7.6
$7.7
$146
Benefits (103 tons)
0.3
0.6
1.0
1.4
1.8
2.2
2.6
3.0
3.4
3.8
4.2
4.6
4.9
5.2
5.5
5.7
5.9
6.0
6.2
6.3
6.4
6.5
6.6
6.7
6.8
6.9
7.0
7.1
7.1
7.2
7.3
45.0
Category 2
Costs (106 $)
$0
$0
$1.9
$1.9
$1.9
$1.9
$3.5
$2.0
$2.0
$2.0
$2.0
$0.6
$0.6
$0.6
$0.6
$0.6
$0.6
$0.6
$0.6
$0.6
$0.6
$0.6
$0.6
$0.6
$0.7
$0.7
$0.7
$0.7
$0.7
$0.7
$0.7
$15.1
Benefits (103 tons)
0
0
0.4
0.7
0.11
0.15
0.19
0.23
0.27
0.31
0.35
0.39
0.43
0.47
0.52
0.56
0.60
0.64
0.69
0.73
0.77
0.82
0.86
0.90
0.93
0.97
1.00
1.03
1.05
1.07
1.09
4.46
132
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