MDIAN
258-012-25-01
DCN: 87-258-012-25-02
EPA-420-R-88-100
February 1988
FEASIBILITY AND CO ST-EFFECTIVENESS
OF CONTROLLING EMISSIONS FROM DIESEL ENGINES
IN RAIL, MARINE, CONSTRUCTION, FARM,
AND OTHER MOBILE OFF-HIGHWAY EQUIPMENT
Final Report Under
EPA Contract No. 68-01-7288
Work Assignment 25
Prepared far:
Office of Policy Analysis
U.S. EPA, PM-221
401 M Street S.W.
Washington, D.C. 20460
Prepared by:
Christopher S. Weaver, P.E.
Radian Corporation
10395 Old Placerville Road
Sacramento, CA 95827
February 1988
10395 Old Placerville Rd./Sacramento, California 95827/(916)362-5332
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RADIAN
«oapo«iir(ON
EXECOTXVS SUMMARY
Diesel engines in off-highway vehicfes^nd other off-highway mobile
equipment, while less numerous than those in highway trucks and buses, are
still significant contributors to NO^ and particulate inventories in many
urban areas. These engines are presently exempt from any emissions control
requirements. Consequently, they produce far more pollution (per unit of fuel
input or work output) than the otherwise similar emission-controlled engines
used in on-highway vehicles. The recent promulgation of stringent NO^ and
particulate emissions standards for diesel engines in on-highway vehicles has
drawn attention to diesel emissions in general, and has raised the question of
whether similar emissions standards might not be appropriate for off-highway
diesel engines.
Background
Emissions from diesel engines used in on-highway trucks and buses
have been regulated with increasing stringency since 1972. New Federal
regulations adopted in 1985 will limit particulate matter (PH) emissions from
heavy-duty diesel engines to 0.6 grams per brake horsepower-hour (g/BHP-hr),
beginning m the 1988 model year. The NO^ emissions limit, currently at 10.7
g/BHP-hr, will be reduced to 6.0 g/BHP-hr in 1990, and to 5.0 g/BHP-hr in
1991. A new PM limit of 0.25 g/BHP-hr (0.1 g/BHP-hr for buses) is also
scheduled for 1991, and a PM limit of 0.1 g/BHP-hr for all vehicles is
scheduled for 1994.
Although they are technically very similar to on-highway diesel
engines, engines used in off-highway mobile equipment such as locomotives,
farm and construction equipment, boats, and similar applications are presently
exempt from any emissions controls. The Clean Air Act gives EPA authority to
regulate "stationary sources" of emissions, and "motor vehicles", but the term
"motor vehicle" has traditionally been interpreted to include on-highway
vehicles only. Since off-highway mobile sources are neither "stationary" nor
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»!!!»*!
"motor vehicles", EPA appears to have no authority to regulate them.
If regulations were considered desirable, Congressional action would be needed
to provide the required authority.
Scope of This Report
Radian Corporation was commissioned by the U.S. EPA, Office of
Policy Analysis to study the feasibility and cost-effectiveness of emissions
controls in off-highway diesel vehicles. This document is the final report of
that study. This report addresses the following major categories of
diesel-engined off-highway equipment:
• Railroad locomotives;
• Marine vessels (except large oceangoing ships);
• Farm equipment;
• Construction and industrial equipment
(including mining and forestry equipment); and
• Mobile Refrigeration Units.
These categories include the most significant classes of mobile
diesel engines except for on-highway vehicles (which are already regulated)
and oceangoing motorships.
Results and Conclusions
Based on the estimates developed for this report, total pollutant
emissions from off-highway diesel engines are large both in absolute terms and
in proportion to their total numbers, power output, and fuel consumption.
Table E-l summarizes the estimated population, annual fuel consumption, and
emissions for the five classes of off-highway diesel engines considered in
this report. Estimated pollutant emissions are reported both in tons per year
and as a percentage of the estimated total emissions of that pollutant by all
sources nationwide. Off-highway diesel engines are estimated to produce about
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TABLE__E-1_. ESTIMATED.NATIONWIDE POPULATION AND EMISSIONS FROM DIESEL ENGINES
USED IN OFF-HIGHWAY APPLICATIONS
Total Fuel
No. of Horsepower Consumption
Engines (1.000s) (1,000 gal)
HC
Emissions (tons/yr)
CO
NO
PM
Locomotives
Medium Speed ^
Percent of Nationwide
Marine Vessels
High Speed
Medium Speed
Total
Percent of Nationwide
26.105
438,000
5.000
61.111
45.471
11.173
56.644
3.409.476
915,671
917.607
1,833,278
443,000
Farm Equipment^
High Speed 3,868.019 332,139 3,021,561
Percent of Nationwide
Construction and Industrial Equipment
30,999 308,558
0.13% 0.40%
14,651
18.811
33.462
0.14%
54.482
85.796
140,278
0.18%
108,603 274,669
, 0.46% •) 0.36%
901,645 37,041
4.162? 0.48%
High Speed 1,047.805 124,056 3.279.661
Percent of Nationwide
Mobile Refrigeration
High Speed 203.000 9.518 494,167
Percent of Nationwide
47,820 ,191,064
\ 0.20% I 0.25%
V 06 •
10,921 44,347
0.05% 0.06%
199,616
244,542
444,158
2.05%
688,874
3.17%
\ 590,372
\ 2.72%
10,988
9.176
.20.164
0.26%
75.103
0.97%
50.021
0.65%
•51
115.520 4.991
0.53% 0.06%
TOTALS
High Speed 5.556.824 511.184 7,711.060
Medium Speed 31,105 72.284 4.327.083
Total 5.587,929 583,468 12.038,143
Percent of Nationwide
181.995 564,562
49.810 394.354
231.805 958,916
0.98% 1.25%
1.594,382 141.103
1.146.187 46,217
2.740.569 187.320
12.63% 2.43%
1 Percent of nationwide emission:; inventory for that pollutant based on EPA (1986).
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"UK*!!
2.75 million tons of NO^ per year, 187,000 tons of particulate matter, 232,000
tons of unburned HC, and 959,000 tons of CO. These values are about 12.6
percent, 2.4 percent, one percent, and 1.25 percent, respectively, of
estimated nationwide emissions of these pollutants from all sources (SPA,
1986).
More significant than the off-highway diesel contribution to the
total emissions inventory is the off-highway contribution to_the total for all
mobile diesel engines, both on and/ off-highway. Table E-2 shows this
calculation. As this table indicates, off-highway diesel,"l"enginesr* ares.
responsible - for/ a disproportionate fraction^of the total: 'accounting for 56'
percent of the NQ^ emissions, 57 percent of CO emissions,' and 48 percent of HC
emissions from mobile diesel engines, but only 41 percent- nf rVie diesel fuel
burned. Their contribution to PM emissions is less than proportionate,
however^ at4_36.5 percent of the total.. Due to limited data, the numbers in
Table E-2 are somewhat crude, but "th'e^'co'nclusion is inescapable; off-highway
diesel engines are currently an important source of emissions, comparable in
magnitude to on-highway dieselsl ~~ '
Diesel engines in on-highway vehicles have been subject to emission
regulations for many years, and have recently received a great deal of
regulatory attention, which will lead to still lower emissions in the future.
Off-highway engines, since they do not fall under EPA's statutory authority,
have not been regulated. For this reason, pollutant emissions per unit of
work produced or fuel consumed by an average off-highway diesel are much
higher than those for an on-highway engine, and the potential for future
reductions in emissions is correspondingly greater.
As describe
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COIPOaaTIOM
TABLE E-2. COMPARISON OF NATIONWIDE FUEL CONSUMPTION AND EMISSIONS
OFF-HIGHWAY VS. ON-HIGHWAY DIESELS
Fuel
Consumption Emissions (tons/yr)
(1,000 gal)
HC
CO
NO
X
PM
Off-Highway Diesels
(mid-1980s)*
Locomotives
3,409,476
30,999
308,558
901,645
37,041
Marine Vessels
1.833 . 278
33,462
140,278
444,158
20.164
Farm Equipment
. 3,021,561
108,603
274,669 •'
"688,874
75,103
Const./Ind. Equipt.
3,279,661
47,820
191,064
590,372
50,021
Mobile Refrigeration 494,167
10,921
44,347
115.520
4,991
Total Off-Highway
.*
12,038,143
231,805
958,916
2,740,569
187,320
On-Highway-Diesels
(calendar 1984)^
Heavy-Duty Vehicles
NA
242,290
693,832
2,136,563
297,357
Light-Duty Vehicles
NA
8.820
28,634
44,052
28,634
Total On-Highway
17,279,650
251,110
722,466
2,180,615
325,991
Total: All Mobile
Diesel Engines
29,317,793
482,915
1,681,382
4,921,184
513,311
Off-Highway as
Percent of All
Mobile Diesels
41.1%
48.0%
57.0%
55.7%
' 36.55
^Source: Radian estimates.
^Source: EPA (1986).
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BAR!*!!
RPM, respectively. Except, for railway locomotives, the, great majority of
off-highway diesel engines.; are high-speed types. These,, share many design
features with on-highway truck and light-duty vehicle engines, so that most
emissions control technologies demonstrated in on-highway engines would be
readily transferable. Mediuo-speed engines are used in railway locomotives
and some marine vessels. Emissions control technology for these engines is
less developed, but even the little .work that has been done shows the
potential for major reductions in emissions. •
Sections Four through Eight of this report include a case-by-case
discussion of applicable emission control technologies and achievable
emissions standards for diesel engines used in each class of off-highway
equipment. Table E-3 summarizes the emissions standards estimated to be
achievable by each class, as well as the percentage reduction from present
levels represented by these standards. In .the intermediatet.term,engines^rin
*allg"classe"srexcepti farm equipment and., construction equipment, we:rer estiaated-.toi-
^fie^apable"ofn meeting emissions standards comparable to the California 1988"
NQ^ and - PM standards , for on-highway vehicle's!. using essentially^ existingC
technb.logy^I^ Construction and" farm equipment" were estimated to require a ¦
higher*. N0~~ limit7' due " to the" limited potential.," for * turbocharging" and
y aftercooling
V Given time to develop advanced emission control technology, it was
estimated that engines in railway locomotives and marine vessels would be able
to comply with emissions standards comparable to the Federal 1991 standards for
on-highway vehicles, while those in mobile refrigeration units should be able
to comply with standards comparable to the 1994 on-highway limits.
\ Con struct ion*"1a tfd^"farm* equipment? could' mee t PM standardsT."siailfl~rT to'Tthe*" 1994
levelS^T KTt^dw^" to^theiir higher load factors—night "notL ber_ able t o^achieve
thej.levei??o"f 0.10 g/BHP-hr mandated for" on-highway engines.* As is also true
of on-highway engines, a reduction in diesel fuel sulfur content might be
required to achieve these low particulate levels'. In addition, construction
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and farm equipment would also, require a slightly higher NO^ licit than that .3
mandated ..for ' on-higbway" "engines"t "due ~ to the limited potential for
"low-temperature "chajfie^cooling"""
The reader is warned that the emissions limits shown in Table E-3
are engineering estimates only, based on very limited data, and intended only
to indicate the potential benefits of regulation in this area. As discussed
"below, additional research to confirm these estimates would be essential
before these or any other emission standards were incorporated into law.
Figures E-l through E-3 show the potential effects of introducing
the emissions standards listed in Table E-3 on NO , HC, and PH emissions from
x
each class of off-highway engines. The leftmost bar for each class represents
the current situation, with no emissions control. The middle bar represents
the emissions that would be experienced if all existing engines met the
"intermediate" emissions standards, and the rightmost bar the emissions that
would result if allTexisting engines~TaeF tfie~^idvanced~techri6rogyn standards.
The net reduction if every off-highway engine in use met the "advanced
technology" standards would be about 1.4 million tons of .NO*, 162,000 tons of
x
HC, and 146,000 tons of PlC^r.^yiarT or - 52-. percent,4 70:- percent, and- 78-
percent, ' respectively, Co£V.the. current3 emissions of these, pollutants from"
off-highway^ diesels'ji In reality, of course this would take a very long time
to achieve, due to the need to turn over the existing engine population.
The cost-effectiveness of controlling off-highway diesel emissions
to at least the intermediate-term standards shown is estimated to be very
favorable compared to the costs of other available emission control measures
of similar significance. Estimated cost-effectiveness values for a number of
specific equipment types are shown in TXableSigi While based on crude
preliminary cost estimates, thesevaP^esj?r
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RADIUM
TABLE 1-3. EMISSIONS STANDARDS ESTIMATED TO BE ACHIEVABLE
BY EACH CLASS OF OFF-HIGHWAY DIESELS
Intermediate
Standard
(g/BHP-hr)
Percent
Reduction
Advanced Technology
Standard
(g/BHP-hr)
Percent
Reduction
Locomotives
NO
HC*
PM
6.0
0.50
0.50
55%
52%
1%
5.0
0.30
0,20
63%
71%
60%
Marine Vessels
Medium-Speed Engines
NO
HC*
PM
0.50
0.50
55%
52%
1%
5.0
0.30
0.20
63%
71%
60%
High-Speed Engines
NO
HC*
PM
6.0
0.50
0.50
45%
38%
17%
5.0
0.50
0.25
55%
38%
59%
¦¦Farm Equipment
NO
HC*
PM
8.0
0.50
0.50
30%
72%
60%"
6.0
0.20
0.15
48%
89%
Const met fori" "Equ ipaent?-
NO 8.0
He 0.50
PM 0.50
12%
32%
36%
6.0
0.20
0.15
34%
73%
81%
Mobile Refrigeration
NO
HC*
PM
6.0
1.0
0.50
49%
10%.
2%
5.0
0.20
0.10
58%
73%
80%
Source: Radian estimates.
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90
80 -
70 _
60 -
50 _
40
20
20
10
0
m
wm
2$i
£m
I
n
M
m
22$
Marine farm* Construction Mobile
Locomotives Vessels Equipment Equipment Refrigeration
zz
Uncontrolled
ESI
Int. Controls
VZ&
Adv. Controls
Figure E-3. Estimated Effect of Emissions Controls
on Total Off-Highway PM Emissions
xi
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TABLE E-4. ESTIMATED COST-EFFECTIVENESS OF "INTERMEDIATE LEVEL"
EMISSIONS CONTROLS FOR DIFFERENT CLASSES OF OFF-HIGHWAY
VEHICLES
1
Cost Effectiveness ($/ton)
NO + HC PM
x
Locomotives
New
$1,073
2
Retrofit
1.332
&
Marine Vessels
Medium Speed
672
_2
2
High-Speed Propulsion
SS8
2
High-Speed Generator
616
Farm Equipment
Large 4WD Tractor
845
3,067
Snail Tractor
2,960
7,607
Combine
848
1,900
Construction Equipment
Hydraulic Excavator
748
8,969
Industrial Tractor
1,567
5.323
Concrate Paver
2,045
3,961
Mobile Refrigerator
Railcar Unit
229
2
Truck/Container Unit
1,909
4
•I
Approximate estimates based on engineering judgement and limited data. See
text Chapters 4-8 for assumptions and limitations.
PH reductions at "intermediate" control level are estimated as small or
negative for these categories. This is due to low FM emissions to begin with,
and the effects of the NO^/PM tradeoff.
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110
100 -
9C
80
70
60
50
40
10
'
111
1
II
Hi
m
%
53
Locomotives
Marine Tina* Construction Mobile
Vessels Equipment Equipment Refrigeration
122 K3 UZ&
Uncontrolled Int. Controls Adv. Controls
Figure E-2. Estimated Effect of Emissions Controls
or 7o t&1 Of f"Hi^twsy HC Emi ssions
x
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L
111
I
m
'/zm
I
I
mm
M§
v&w
A
Marine Fain* Construction" Mobile
Locomotives Vessels Equipment Equipment Refrigeration
IZ3 K3 WZ&
Uncontrolled Int. Controls Adv. Controls
Figure E-l. Estimated Effect of Emissions Controls
on Total Off-Highway NO Emissions
X
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Limitations and Caveats
This report presents the results of a preliminary investigation of
controlling emissions from off-highway diesel vehicles. The principal purpose
of this investigation was to determine whether these vehicles offer sufficient
potential for technically feasible and cost-effective emission reductions to
justify further attention from EPA. The" study results indicate that^regulation
of' off-highway, emissions" could"" poten tiallyl*"resuIC _ la rgeT "cost-effective
"emission reductions. Thus, " furtherinvestigation" and "possible regulatory
"action are * indicated. However, this investigation does not conclusively
demonstrate, and should not be interpreted as demonstrating that the
levels of emissions control assumed here are technically feasible, or
achievable within any particular time frame, or at any particular cost. Many
issues remain to be resolved before any realistic emissions standards or
compliance schedules could be established.
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For comoarison, the fuel cost alone for reducing the 1991 NO %
x*
standard for heavy-duty cn-highway engines from 5.0 to 4.0 g/BHP-hr (a step
which is often suggested) is estimated at^ab^it $2,000 per,ton (assuming a 4
percent fuel economy penalty and fuel at $0.80 per gallon excluding taxes).
The incremental cost-effectiveness, of„ the 1994JPM standard of 0.1 g/BHP-hrl for,
heavy-duty on-highway engines has been estimated at about* seven to eleven
thousand dollars per ton (Weaver and Klausmeier, 1987a).
Recommendations
1. The development of^^more^ accurate/ andr"representative^"dutyi
cycles^ Remission.. „ factors, and emission . ' inventories , "for
off-highway diesel vehicles would be highly desirable, as would^
the- development of suitably representative emissions . test?
procedures! These data and procedures would be valuable in
developing and evaluating any future regulations in this area.
However, EPA funding of emissions control experimeoration is
not recommended beyond a very preliminary level. Experience
has shown that this type of work is more appropriately left to
the engine manufacturers.
2. Were emissions regulations to be established for farm and
construction equipment engines, careful consideration should be
given to phase-in mechanisms in order to avoid undue burden on
the industry. An averaging, trading, and banking approach with
"crawling" target levels, such as that discussed ia Section
6.5, would be one fairly straightforward way to do this.
3. In the event that emissions regulations are established for new
medium-speed marine and locomotive engines, consideration
should also be given to establishing retrofit requireaents for
older engines in these categories. These requirements could
most conveniently apply at the time of rebuild.
xiii
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"ASIAN
TABLE OP CONTENTS
Section Page
EXECUTIVE SUMMARY i
LIST OF TABLES xviii
LIST OF FIGURES xxi
1.0 INTRODUCTION 1-1
1.1 Background,.... 1-1
1.2 Nature and Scope of this Report..,, 1-2
1.3 Guide to the Remainder of the Report. .1-4
1.4 Limitations and Caveats....... 1-5
2.0 DIESEL ENGINE CHARACTERISTICS AND CLASSIFICATION 2-1
2.1 Engine Classification 2-1
2.2 Engine Technology 2-5
2.3 Diesel Emission Fundamentals 2-10
2.4 Emission Regulations ...» 2-14
3.0 TECHNOLOGY FOR EMISSION CONTROL 3-1
3.1 High-Speed Engines..*. 3-1
3.2 Medium-Speed Engines 3-9
4.0 LOCOMOTIVES 4-1
4.1 Engine Characteristics and Operating Conditions 4-1
4.2 Current Emission Factors 4-3
4.3 Engine Population and Emissions Inventory 4-8
4.4 Emissions Test Cycle............ 4-10
4.5 Feasibility of Emissions Control 4-11
4.6 Cost-Effectiveness Analysis 4-14
xv
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l(l»OII»IS»
TABLE OF CONTENTS (Continued)
Section Page
5.0 MARINE VESSELS 5-1
5.1 Engine Characteristics and Operating Conditions 5-1
5.2 Current Emission Factors 5-3
5.3 Engine Population and Emissions Inventory..... 5-6 •
5.4 Emissions Test Cycle 5-9
5.5 Feasibility of Emissions Control, 5-10
5.6 Cost-Effectiveness Analysis. 5-13
6.0 FARM EQUIPMENT 6-1
6.1 Engine Characteristics and Operating Conditions 6-1
6.2 Current Emxssion Factors.»•#•••»*¦•*•• 6—2
6.3 Engine Population and Emissions Inventory........... 6-5
6.4 Emissions Test Cycles 6-7
6.5 Feasibility of Emissions Control 6-8
6.6 Cost-Effectiveness Analysis 6-12
7.0 CONSTRUCTION AND INDUSTRIAL EQUIPMENT 7-1
7.1 Engine Characteristics and Operating Conditions 7-1
7.2 Current Emission Factors 7-2
7.3 Engine Population and Emissions Inventory........... 7-4
7.4 Emissions Test Cycles 7-7
7.5 Feasibility of Emissions Control 7-8
7.6 Cost-Effectiveness Analysis 7-10
xvi
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(•IttlillSN
TABLE OF CONTENTS (Continued)
Section Page
8.0 MOBILE REFRIGERATION UNITS 8-1
8.1 Engine Characteristics and Operating Conditions 8-1
8.2 Current Emission Factors...... 8-2
8.3 Engine Population and Emissions Inventory...... 8-4
8.4 Emissions Test Cycles 8-4
8.5 Feasibility of Emissions Control 8-6
8.6 Cost-Effectiveness Analysis'.... 8-6
9.0 SUMMARY. CONCLUSIONS AND RECOMMENDATIONS 9-1
9.1 Summary and Conclusions 9-1
9.2 Recommendations 9-10
10.0 REFERENCES 10-1
APPENDIX A: DERIVATION OF LOCOMOTIVE EMISSION FACTORS
xvii
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coiwaaavioN
LIST OF TABLES
Table Page
E-l Estimated Nationwid# Population and Emissions from
Diesel Engines Used in Off-Highway Applications........... 2-3
E-2 Comparison of Nationwide Fuel Consumption and
Emissions Off-Highway VS. On-Highway Diesels.. 1-5
E-3 Emissions Standards Estimated to be Achievable by
Each Class of Off-Highway Diesels....... E-7
E-4 Estimated Cost-Effectiveness of "Intermediate Level"
Emissions Controls for Different Classes of Off-Highway .
Vehicles E-l 2
1-1 Deliveries of Diesel Fuel for On- and Off-Highway
Vehicles and Equipment..... 1-3
2-1 Characteristics of Some Common Off-Highway Engine
Series. 2-3
2-2 Federal and California Emissions Regulations for
Heavy-Duty Diesel Engines 2-15
3-1 Techniques for Diesel Engine Emissions Control 3-3
3-2 Effect of Engine Modifications on GM Electro-Motive
Division (EMD) 16V-64E Engine Performance and Emissions... 3-11
4-1 Measured Locomotive Emissions from Published Studies
Expressed in Grams Per Horsepower Hour on Line Haul
Cycles 4-4
4-2 Emission Factors for Railway Locomotives 4-5
4-3 Population, Fuel Consumption, and Estimated Emissions
for Railway Locomotives 4-9
4-4 Estimated Achievable Emissions Control Standards for
Locomotive Engines 4-13
4-5 Estimated Cost-Effectiveness of Emissions Control for
New Railway Locomotives 4-15
5-1 Estimated Current Emission Factors for Diesel Engines
Used in Marine Applications..... 5-5
xviii
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LIST OF TABLES (Continued)
Table Page
5-2 Estimated Nationwide Population and Emissions from
Diesel Engines Used in Marine Applications 5-7
5-3 Estimated Achievable Emissions Control Standards for
Marine Diesel Engines 5-11
5-4 Estimated Cost-Effectiveness of Emissions Control for
Diesel Engines Used in Marine Applications 5-14
i
6-1 Emission Factors for Farm Equipment 6-4
6-2 Estimated Population, Fuel Consumption, and Emissions
from Diesel Engines Used in Farm Equipment 6-6
6-3 Estimated Achievable Emissions Control Standards for
Diesel Engines Used in Farm Equipment 6-10
6-4 Estimated Cost-Effectiveness of Emissions Control for
Diesel Engines Used in Farm Equipment 6-13
7-1 Estimated Current Emission Factors for Diesel Engines
Used in Construction and Industrial Equipment 7-3
7-2 Estimated Population, Fuel Consumption and Emissions
from Diesel Engines Used on Construction and Industrial
Equipment 7-5
7-3 Estimated Achievable Emissions Control Standards for
Diesel Engines Used in Construction and Industrial
Equipment 7-11
7-4 Estimated Cost-Effectiveness of Emissions Control for
Diesel Engines Used in Construction Equipment 7-13
8-1 Estimated Current Emission Factors for Diesel Engines
Used for Mobile Refrigeration 8-3
8-2. Estimated Nationwide Population, Fuel Consumption, and
Emissions from Diesel Engines Used for Mobile
Refrigeration 8-5
8-3 Estimated Achievable Emissions Control Standards for
Diesel Engines Used in Mobile Refrigeration 8-7
xix
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RADIAN
LIST OF TABLES (Continued)
Table gage
^3-4 Estimated Cost-Effectiveness of Emissions Control
for Diesel Engines Used in Mobile Refrigeration 8-8
9-1 Estimated Nationwide Population and Emissions from
Diesel Engines Used In Off-Highway Applications 9-2
9-2 Comparison of Nationwide Fuel Consumption and Emissions
Of f-Highway 7s. On-Higbway D iesels 9-3
9-3 Emissions Standards Estimated to be Achievable by Each
Class of Off-Highway Diesels ." r 9-5
r f *
9-4 Estimated Cost-Effectiveness of "Intermediate Level"
Emissions Controls for Different Classes of Off-Highway
Vehicles 9-11
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RADIAN
ooipoaifion
LIST OF FIGURES
Figure Page
E-l Effect of Emissions Controls on Total Off-Highway
NO Emissions. E-9
x
E-2 Effect of Emissions Controls on Total Off-Highway
HC Emissions E-10
E-3 Effect of Emissions Controls on Total Off-Highway
PM Emissions E-ll
2-1 Diesel Engine Combustion Systems....... 2-6
9-1 Effect of Emissions Controls on Total Off-Highway
NO Emissions 9-7
x
9-2 Effect of Emissions Controls on Total Off-Highway
HC Emissions. 9-8
9-3 Effect of Emissions Controls on Total Off-Highway
PM Emissions 9-9
xxi
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1.0 INTRODUCTION
Diesel engines in off-highway vehicles and other off-highway mobile
equipment, while less numerous than those in highway trucks and buses, are
still significant contributors to "NO^ and particulate inventories in many urban
areas. These engines are presently exempt from any emissions control require-
ments. Consequently, they produce far more pollution (per unit of fuel input
or work output) than the otherwise similar emission-controlled engines used in
on-highway vehicles. The recent promulgation of stringent N0^ and particulate
emissions standards for diesel engines in on-highway vehicles has drawn atten-
tion to diesel emissions in general, and has raised the question of whether
similar emissions standards might not be appropriate for off-highway diesel
engines.
1.1 Background
Emissions from diesel engines used in on-highway trucks and buses
have been regulated with increasing stringency since 1972. New Federal regula-
tions adopted m 1985 will limit particulate matter (PM) emissions from
heavy-duty diesel engines to 0.6 grams per brake horsepower-hour (g/BHP-hr),
beginning .in the 1988 model year. The N0^~ emissions, limit, currently at 10.7
g/BHP-hr, will be reduced to 6.0 g/BHP-hrl in; 1990V and to 5.0"g/BHP-Kr" in. 1991.
A new PM limit of 0.25~"g7BHP.-h'r" (0.1 g/BHP-hr for buses) is also scheduled for
1991, and a PM limit of 0.1 g/BHP-hr for all vehicles is scheduled for 1994.
Although they are technically very similar to on-highway diesel
engines, engines used in off-highway mobile equipment such as locomotives, farm
and construction equipment, boats, and similar applications are presently
exempt from any emissions standards. The Clean Air Act gives EPA authority to
regulate "stationary sources" of emissions, and "motor vehicles", but EPA
interprets the term "motor vehicle" to include on-highway vehicles only. Since
off-highway mobile sources are neither "stationary" nor "motor vehicles", EPA
1-1
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RADIAN
considers that it has no authority to regulate them. EPA does have authority
to regulate emissions from stationary internal-combustion engines used for
cogeneration," emergency generators, irrigation pumping, and so forth, but New
T
Source Performance Standards (NSPS) for these' engines have not been
promulgated.
1.2 Nature and Scope of This Report
Radian Corporation was commissioned by the U.S. EPA, Office of Policy
Analysis to study the feasibility and cost-effectiveness of emissions controls
in off-highway diesel vehicles. This document is the final report of that
study. This report addresses the following major categories of diesel-engined
off-highway equipment:
• Railroad locomotives;
• Marine vessels (except large oceangoing ships);
• Farm equipment;
• Construction and industrial equipment
(including mining and forestry equipment); and
• Mobile refrigeration units.
These categories include all large groups of mobile diesel engines
except for on-highway vehicles (which are already regulated) and oceangoing
motorships. 'Engines* usea- tor' generators," pumps,.: ana compressors and diesel
lawnTandrgarden^equipment" were' also* included in 'the original scope of the
study, and these (along with all the categories listed above) were examined in
a preliminary report (Weaver and Pugh, 1986). They, were subsequently dropped;
due^ to..their insignificant contribution to* total emissions.
Table 1-1 gives an idea of the relative importance of on-highway and
off-highway diesel engines. This table lists U.S. Department of Energy
estimates of the amount of distillate diesel fuel consumed by each equipment
1-2
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RADIAN
TABLE 1-1. DELIVERIES OF DIESEL FUEL FOR ON- AND
OFF-HIGHWAY VEHICLES AND EQUIPMENT
Class
Annual Deliveries
1000s of Gallons
Farm
Locomotive
Marine Vessels
Construction and
Other Off-Highway;
Off-Highway Total
Qn-Highway Total
Total Mobile Diesel Engines
Off-Highway as Percent of Total
3,161,338.
3,209,729
1,894,265
rl .'616.685 *
9,882,017
17,279,650
27,161,667
36.4%
Source: EIA, 1985,
1-3
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RADIAN
cei»ei*>iai
category in 1985. As chis table indicates, each of the individual categories
of off-highway mobile sources considered in this report is small compared to
on-highway vehicles (trucks, buses, and diesel passenger cars). Collectively,
however, these sources are quite significant. ' Asx can be seen, total
off-highway-jdieseli. fuel consumption is equal to 57 percent of the on-highwa'y
total. Furthermore, some of the fuel used in tfie-on-highway^ category is used
for powering mobile refrigeration units. Emissions from these units are
unregulated, and they are covered in this report. It is apparent that
off-highway and other unregulated diesel emissions sources must account for a
very significant fraction of total diesel engine emissions in the United
States.
1.3 Guide to the Remainder of the Report
This report is divided into nine sections, of which this Introduction
is the first. Section Two, following, provides the technical background for
the succeeding sections. It discusses the classification and general charac-
teristics of off-highway diesel engines, and the fundamentals of diesel
emissions. Section Three discusses the current state of the art in diesel
emissions control, based largely on on-highway engine results. Sections Four
through Eight each deal with one of the equipment categories listed in Section
1.2 above. Engine characteristics and operating conditions, estimates of
current emission factors, and a discussion of applicable emission control
technology are given for each category. Estimates of the total engine popula-
tion, fuel use, and nationwide pollutant emissions for each category are also
presented in each section.
Following the five sections dealing with individual engine
categories, Section Nine summarizes the results of the study and our
conclusions. This section also contains our recommendations for further
research, and for policy action.
1-4
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1.4
Limitations and Caveats
This report presents the results of a preliminary investigation sf
controlling emissions from off-highway diesel vehicles. The principal purpose
of this investigation was to determine whether these vehicles offer sufficient
potential for technically feasible and cost-effective emission reductions to
justify further attention from EPA. The study results indicate that regulation
of off-highway emissions could potentially result in large, cost-effective
emission reductions. However, this investigation does not demonstrate, and
should not be interpreted as demonstrating that any particular level of
emissions control is technically feasible, or achievable within any particular
i
time frame, or at any particular cost.
While this report presents some approximate estimates of the emission
levels achievable, and the costs of achieving them, the reader is cautioned not
to misinterpret these. These are preliminary estimates only, made for the
purpose of assessing what might be achieved through regulations—they are not
definitive. Many issues remain to be resolved before any realistic emissions
"standards could be specified. These issues include: ."representative? tes,t
cycles') for the different off-highway applications; .emissio'hsX level'slsL from
. existing"^_engines" using ."these" representative test""cyclel; ef.fects~ZofI.availab 1^
emission-y*Sontrol& techniqiies > onT emissions'"-meas'ured'^wer3 tKes¥S't>"sjt',2,cyclesl
actu"al'*co s ts" of-vehicle" redesi^rtoT^a«ommodat"e^mission 1 controfs; "feasibility
of some""emission~control techniques in seme applications; and the"potential for
emissions compliance through use of alternative fuels such as methanol and
compressed natural gas. Further research and much more detailed evaluation of'
each of these issues would be required before any regulations could be adopted.
1-5
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RADIAN
(•¦ieitf ten
2.0 DIESEL ENGINE CHARACTERISTICS AND CLASSIFICATION
y
This section provides an overview of diesel engine characteristics
and technology, diesel pollutant emissions, and emission regulations. It is
intended to supply background information for those previously unfamiliar with
diesel engines and emissions control, and to establish definitions for the more
technical chapters which follow.
2.1 Engine Classification
Diesel engines are conventionally divided into three major classes on
the basis of size and rotational speed (Lilly, 1984). These classes are:
1. Slow-speed engines (0-600 RPM)
2. Me^illo^peed""engine"s (600-1300" RPM)
3. High-speed engines (1300 RPM up)
Slow-speed engines are used only," in^ large*"ships (where they are
typically direct-coupled to the propeller driveshaft), and In a very few
stationary applications. They will* not be considered' further! ini'this. report.^
Medium-speed engines are used in railway locomotives, ships and large boats, as
well as stationary generating and pumping applications. High-speed engines are
by far the most numerous class, being used in highway trucks and buses, con-
struction machinery, boats, farm equipment, and numerous other applications.
Due to the economics of mass production, diesel engines' used' in
"mobile*-of f-highway applications are typicallya"members "of "a"family' or series of
engines; sharing the same basic cylinder dimensions, but with varying types of
aspiration (naturally aspirated, turbocharged, or turbocharged/aftercooled) and
numbers of cylinders. Thus, a wide range of power requirements can be
satisfied using the same basic combustion system. As an extreme example, the
2-1
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RADIAN
tei»»aavi«a
venerable Detroit Diesel-Allison 71 series engines are available in roots blown
and turbocharged versions, with air-air or air-water aftercooling, and with 2,
3, 4, 6, 8, 12, or 16 cylinders. •
Table 2-1 lists a number of the more popular engine series, along
with some of their key technical characteristics. These characteristics are
discussed in Section 2.2.
As Table 2-1 indicates, off-highway diesel engines can be grouped
into several general groups.
<3?SUP i. Medium-speed engines used in railway locomotives and marine
vessels.
6,£IBUP "2. Medium-sized, high-speed engines similar to those used - in
heavy-duty* trucks. This is the largest group of off-highway
diesel engines. Four, six, and eight-cylinder engines in this
class are commonly used in agricultural and construction machin-
ery and (in emission-controlled versions) for highway trucks.
Larger 12 and 16-cyUnder engines in the same series are used in
marine and heavy construction applications.
^ 3. Large high-speed" engines, having sizes and power levels greater
than those used in on-highway truck applications. Turbocharged
and often intercooled, these engines are used mostly in marine
and heavy earthooving applications.
4. Small high-speed "engines (often derived from light-duty automo-
tive technology), and typically ranging from*10 'to about 80
'horsepower. These engines are mostly naturally-aspirated, and
may use either direct or indirect injection.
2-2
-------
CO«PO>1VIOH
TABLE 2-1. CHARACTERISTICS OF SOME COMMON OFF-HIGHWAY ENGINE SERIES
Engine Disp, Bore Asp. Inj.
Series (1/cyl) (in.) Types System
Config. Horsepower
Offered Range Application
Class 1: Hedium-Soeed
GM Electromotive Division
567
9.3
8.5
B,TA
UI
V8.V12.716
600-2750
R.B.G
645
10.6
9.1
B ,TA
UI
V8.V12.V16.V20
800-3900
R.B.G.C
710
11.7
9.1
TA
UI
V8.V12.V16.V20
1800-4800
R.B.G
General Electric
,
FDL
N,TA
UI
V8.V12.V16 '
1800-3600
R
Gate roil lar
3600
18.5
11.0
TA
UI
6L.8L.V12.V16
1300-4500
R.B.G
Class 2: High-Speed,
Truck
Type
Caterpillar
3200
1.31
4.5
N.T.TA
IL
4L.V8
71-355
T.C.A
3300
1.75
4.8
N.T.TA
IL
4L.6L
85-335
T.C.A.G
3400
2.44
5.4
T.TA
IL
6L.V8.V12
215-838
T.C.A.G,B
Cummins
NH
2.33
5.5
T,TA
" UI
6L.V12
250-900
T.A.C.B.G
L10
1.67
4.9
T.TA
UI
6L
250-290
T.A.C.G
B
0.98
4.0
N,T,TA
EL
3L.4L.6L
66-177
T.A.C
C
1.38
4.5
N.T.TA
IL
6L
150-234
T.A.C
GM Detroit Diesel-Allision
Division
92
1.51
B,T»TA
UI
V6.V8.V12.V16
270-960
T.A.C.B.G
71
1.17
4.25
B.T.TA
UI
2L.3L.4L.6L.
64-760
T.A.C.B.G
V6.V8.V12.V16
John Deere
i
300
0.98
4.19
N.T
DP
3L.4L.6L
56-142
C.A.(T)J
400
1.27
4.56
N.T.TA
DP
6L
134-226
C.A.(T)
""Class" Three:
Large High-Speed Engines*
Caterpillar
3500
4.31
6.7
TA
UI
V8.V12.V16
600-2000
C.B.G
300
4.03
6.3
TA
IDI
V8.V12.V16
500-1000
C.B.G
(Continued)
2-3
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RADIAN
TABLE 2-1. (Continued)
Engine Disp. Bore Asp. Inj. Config. Horsepower Application
series (1/ejrn ^ (in.) Type. Syste. Offered Range
Cummins
K 3.14 6.25 T.TA
GM Detroit Diesel-Allison Division
149 2.45 5.75 B.T.TA
Class Four: Small High-Sueed Engines
Kubota
3.23" St. .37-.46 various N.T
?anmar
TN82 0.46 3.23 N,T
T95 0.78 3.74 N.T
UI 6L,127,167
UI 87.127,16V
DP 3L.4L.6L
DP 3L.4L
DP 3L.4L
450-2000 C,B,G
530-1800
. 19-46 A,C,L
30-47 A,C,L
44-77 A.C.L
Aspiration
H - naturally aspirated
B - Roots-blown
T - turbocharged
TA - turbocharged/aftercooled
Combustion System
UI — DI w unit injectors
IL — DI v in-line pump
DP — DI w distributor pump
IDI - indirect injection
*Truck versions of these engines
Applications
T - On-highway trucks
A - Agricultural Equipment
C - Construction/Mining/
Industrial equipment
B - Boats
L - Locomotive
G - Generators/stationary power
Rf - Mobile refrigeration
are under development.
2-4
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TABLE 2-2, FEDERAL AND CALIFORNIA HUSSIONS REGULATIONS FOR HEAVY-DUTY DIESEL ENCINES
CO
(g/BHP-hr)
HC
(g/BHP-hr)
NO
(g/BHP-hr)
PM
(g/BHP-hr)
Teat
Procedure
Smoke Opacity
(Ace/Lug/Peak, I)
Federal '<
1974-1978
1979-1984
40
25
1.5
16a
ioa
NR
NR
13-Mode
13-Hode
20/15/50
2H/15/50
1985-1987. ,
15.5
1. 3i
10.7
NR
Trans ient
20/15/50
1988-1989
15.5
1.3
10.7
0.6
Transient
20/15/50
1990
15.5
1.3
6.0
0.6
Trana ient
20/15/50
1991-1993
15.5
1.3
5.0
0.25
Transient
20/15/50
1994*
15.5
1.3
5.0
0.1
Transient
20/15/50
California
1973-1974
40
16a
NR
13-Mode
b
1975-1976
30
ioa
NR
13-Mode
D
1977-1979
25
1.0
7.5
NR
13-Mode
D
1980-1983
25
1.0
6.0a
NR
13-Mode
D
¦¦ |r
T984-198/
1988-1990
1991-1993
1994*
15.5
15.5
15.5
15.5
1.3
1.3
1.3
1.3
5.1
6.0
5.0
5.0
NR
0.6
0.25
0.1
Trans ienti
Transient
Trans ient
Transient
b
b
b
NR: Not regulated
Sum of NO plus HC emissions.
* r
Federal Smoke Standard applies.
-------
carbon monoxide (CO), hydrocarbons (HC), oxides of nitrogen (NOx), and (begin-
ning in model year 1988) particulate matter (PM). ~ As-, a." practical matter.
_ — ... * ~>T *sr> i , ...»
however, only the NO^ and FM regulations are of much significance, since diesel
HC and CO eoissions are much lower. than, the standards (which were written for
gasoline engines).
A separate regulation also limits the maximum smoke opacity for
on-highway diesel engines. This had some effect in limiting particulate
emissions prior to the establishment of the PM standard. However, compliance
with future PM emissions limits will result in smoke "opacity levels far below
the regulated values*," essentially rendering* the opacity, regulation„irrelevant^
Test procedures—the test cycles and other procedures under which
emissions are measured are as important as the numerical emissions limits.
Until 1985, gaseous_emissions were measured on the' "13-modef..cycle? This cycle
consisted of steady-state'operation at ten different power and"speed settings,
with intervening pe riods .** of idle .J Since diesel HC, CO, and PH emissions are
heavily influenced by transient operation, the'steady-stats' 13-mode "procedure
waa 'considered7ar"po or'p r ed 1 c tora"of U inruse'Iemissions-of^these!- pollutants by*1
highway^ vehicles? For this reason, it has been superseded'^by| the current
Federal Heavy-Duty Transient- Test Procedure'. In this procedure, engine speed
and load are continuously varied according to a fixed schedule, which is
intended7*:o simulate typica^'^urban^ driving*?
Unlike highway, trucks, most off-highway diesel applications include
little transient operation- (construction, "equipment 'is the'- major exception).
Thus, the 13-mode cycle, with its steady-state operation,' may produce more
representative results than the transient procedure for these engines. This is
fortunate,' since virtually all of the available data on off-highway diesel
T«- " * !-> _ , »
emissions are based on~"the"13-mode or some other-steady-state operating cycle.
Appropriate test cycles for individual classes of equipment are discussed
further in Sections Four through Eight.
2-16
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RADIAN
(•itaiifiia
4.0 LOCOMOTIVES
Railroad locomotives are overwhelmingly diesel powered, and7" their
large numbers and large power output per unit make then one of the most signif-
icant off-highway emission sources. Railroading has undergone major changes in
the last decade, due to the impact of higher interest rates, high fuel prices,
and deregulation. These have resulted in a smaller number of locomotives being
used more intensively than in the past, and in considerable technical upgrading
of existing locomotives. These trends have probably had the effect of lowering
railroad emissions (as well as fuel consumption) significantly. However, sales
of new locomotives have dropped dramatically since the late '70s, resulting in
a slower turnover of the existing fleet.
4.1 Engine Characteristics and Operating Conditions
IL—' ¦ ¦ A- .. . —I
Modern railway locomotives are almost exclusively diesel-electric.
In this arrangement, the diesel prime mover drives an electric generator;
current from which drives the individual electric traction motors that drive
the wheels. This has the effect of isolating the diesel engine from changes in
locomotive speed and load. The locomotive control system provides for eight
engine/generator power levels or "notches", plus idle and dynamic brake (in
which the wheel motors are used as generators to slow the train). In any given
notch, the diesel engine runs at constant speed and load. Engine RPM and power
output change only as a result of changes in the notch setting. Thus,
transient effects on locomotive emissions are probably minimal.
In 1982, the average horsepower for all locomotives was 2,341 (Sta-
tistical Abstract of the U.S., 1985). Individual locomotives range from under
1,000 hp to over 7,000 hp (McDonald, 1986). Units 1,500 hp and below are
generally used exclusively for switching and transfer purposes (moving small
groups of cars around a switchyard, or delivering them within an urban area).
Switching locomotives make up approximately 19 percent of the U.S. locomotive
4-1
-------
population (Ingalls, 1985). Larger general-purpose locomotives (typically
2,000 to 4,000 hp) are designed primarily for line-haul (intercity) o-peration.
However, many larger general-purpose locomotives (especially older ones) are
also used in switching and transfer applications. Based on data in Ingalls
(1985), Radian estimated that about 8,700 of the 22,900 locomotives used in
1986 by U.S. Class 1 railroads were assigned to line-haul service, with the
rest being used in switching and transfer applications. Line-haul operation is
estimated to account for about 72 percent of total railroad fuel use, however
(calculated from Ingalls, 1985).
The vast majority of diesel-electric locomotives are powered by
medium-speed, large-bore diesel engines of 1,000 to 4,000 hp. Ninety-five
percent of all U.S. locomotives in use were manufactured by just two companies:
General Electric (14 percent) and the Electromotive Division (EMD) of General
Motors (81 percent) (Ingalls, 1985). Most of the ranainder were produced by
Bombardier, a Canadian company, using Alco engines. Some of the
recently-introduced Caterpillar 3600-series engines have also been used in
locomotive applications.
EMD locomotives are powered by EMD-produced, large-bore, medium-speed
(900-1,000 RPM maximum) two-stroke diesel engines driving electric generators.
Current EMD general-purpose units are powered by turbocharged 16-cylinder
engines of 645 and 710 cubic inch displacement per cylinder, and have a horse-
power range from 2,200 hp to 3,950 hp. EMD offers switching locomotives
powered by eight and twelve-cylinder versions of the 645 engine. These engines
are typically Roots-blown and generate 1,100 hp to 1,650 hp.
The EMD 645 and 710-series engine families are direct descendents of
the EMD 567-series Roots-blown locomotive engines originally introduced in
1938. This engine family has been continuously improved and uprated over the
years with the addition of turbocharging, intercooling, increased displacement
per cylinder (to 645 cubic inches in 1966, 710 in 1985), improved component
designs, and higher power ratings. As a result of IMD's design philosophy,
most of the improved components developed over the years can be retrofit to
4-2
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RADIAN
existing engines when they are rebuilt (Kotlin and Williams, 1975). ks a
result, many different versions of the EMD engines are now in service, incorpo-
rating varying levels of technology and having varying emissions levels.
General Electric line-haul and general purpose locomotives are also
powered by large-bore, medium-speed diesel engines driving electric generators.
GE general purpose units are typically powered by GE FDL-12 cylinder, 3,000
hp turbocharged engines and have a maximum speed of 70 mph. GE (and also ALCO)
engines differ from EMD engines in using a four-stroke rather than a two-stroke
cycle. The GE FDL series runs from an 8 cylinder, 1,800 hp unit to a pair of
16 cylinder, 3,600 hp units (Ingalls, 1985). Most current GE switching units
are powered by high-speed (1800 RPM) diesel engines purchased from an outside
supplier—typically twin Cummins 6 or 8 cylinder, 300 to 550 hp, 4 stroke,
turbocharged engines.
4,2 Current Emission Factors
Gaseous emission factors (HC, CO, NO^) and operating cycles for
locomotives were addressed in a recent report by Southwest Research (Ingalls,
1985). Ingalls compiled and compared gaseous emission factors from a number of
published reports and manufacturer's data. Emission factors for a number of
specific engine technologies are shown in Table 4-1. Ingalls then combined the
emission and fuel consumption factors shown in the table, using data on
locomotive populations, to arrive at the composite emission factors shown in
Table 4-2. However, Ingalls failed to account for the fact that older
locomotives are likely to have been rebuilt using newer injector and
combustion-system technology, and that the older and less-efficient locomotives
probably see less intensive use. As a result, the composite factors shown in
Table 4-2 probably overestimate HC and CO emissions somewhat, and may
underestimate NO^, Possible malfunctions and in-use "deterioration would tend
to increase HC and 00, possibly offsetting this effect.
4-3
-------
TABLE 4-1, MEASURED LOCOMOTIVE EMISSIONS FROM PUBLISHED STUDIES
EXPRESSED IN GRAMS PER HORSEPOWER HOUR OH LINE HAUL CYCLES
Numbe r
Avg,
Emissions, R/bhp-hr,
(range)
Engine Description
Tested
HC
CO
NO
X
General Electric Engines
FDL,
old speed schedule
(1957 to approx. 1974)
4
2.2 (1.7 to 2.5)
4.2 (3.6 to 4.5)
14.0 (10.9 to 18.9)
FDL,
new speed schedule
(approx. 1973 to present)
5
2.3 (2.0 to 2.6)
2.5 (2.0 to 3.0)
14.2 (10.4 to 19.7)
FDL,
new speed sch, low sac injectors
1
0.6
Electromotive Division
1.8
10.7
EMD
567 spherical injectors* pre 1959
1
• 2.7
6.4
12.1
EMD
567 needle injectors 1959 to 1966
1
1.2
10.7
9.8
EMD
567 low sac injectors (retrofit
after 1972)
1
0.7
7.4
13.0
EMD
645E blown, needle injector
(1966 to 1972)
unknown
1.1
10.8
12.5
EMD
645E turbo, needle injectors
(1966 to 1972)
0.8 (0.7 to 0.9)
3.2 (2.5 to 4.0)
11.6 (8.7 to 11.6)
EMD
645F3B turbo, low sac injectors
unknown
0.4*a*
0.6<*>
14.1(a)
(a)
on UIC/ORE cycle
Source: Ingalls (1985)
-------
RADIAN
coavoaAVION
TABLE 4-2. EMISSION FACTORS FOR RAILWAY LOCOMOTIVES
Source HC CO NO PM
x
Ingalls (1985) Composite
Switch 47.4 86.6 468
Line-haul 38.9 226 558
Combined 41.3 187 „ 533
SWRI Studies
GE 12-7FDL
Switch 106 229 537 40
Line-haul 63 162 403 17
Combined 73 177 . 433 22
EMD 12-645E31
,1
2
Switch 33 104 577 12
Line-haul 18 95 537 12
Combined 22 97 546 12
Best Estimate
Switch 47.4 86.6 468 40
Line-haul 38.4 226 558 13J
Combined 41.3 187 533 20
1Calculated by Radian using data from SWRI, These tests were described by
Baker et. al., (1984).
2
Radian estimate, assuming a mix of old and new locomotive engines.
3,
Radian estimate, assuming 80% EMD and 20% GE engines.
4-5
-------
BT JlPlft W
eOI»«l*TiOK
To obtain more representative data on railway emissions, the Associa-
tion of American Railroad-! (AAR) commissioned measurements on 40 locomotives in
the earljs&'80s. Although these data have been released to EPA, they have not
been made public, and Radian was unable to obtain access to them. These data,
if available, would shed additional light on the question of appropriate
gaseous emission factors for locomotives.
Due to the difficulty of building an appropriately-sized dilution
tunnel, data on particulate emissions from diesel locomotives are extremely
scarce. Our literature survey turned up measurements on only four engines, of
which three were conducted at Southwest Research Institute (SWRI). The fourth
was made by EMD, using a different procedure, and may not be comparable to the
three SWRI measurements.
SWRI performed gaseous and particulate emissions measurements on one
EMD 12-645E3 and one GE 12-7FDL engine as part of a study of the effects of
heavy blended fuels (Baker et al., 1984). Due to uncertainties in the mass
flow measurements, Baker et al. reported the emissions data in terms of concen-
tration, rather than g/BHP-hr. At Radian's request, however, SWRI recalculated
the modal emissions data for the baseline tests (using standard diesel #2) to
report g/BHP-hr and lb/1000 gallons. From these data, Radian was able to
calculate cycle-weighted emission factors for HC, CO, NO^ and particulate
matter. The results of these calculations are also shown in Table 4-2; the
data and calculations themselves are given in Appendix A.
As Table 4-2 indicates, particulate emissions from the two modern,
turbocharged/intercooled locomotive engines tested by SWRI are relatively low
compared to other off-highway diesel engines—corresponding to about .26 and
.48 g/BHP-hr for the EMD and GE engines, respectively. Earlier SWRI data on an
EMD 2-567 engine show considerably higher PM emissions, however (Baker, 1980).
These data showed PM emission factors on 39-cetane fuel ranging from 0.7 to
1.25 g/BHP-hr, depending on operating conditions. At the higher BSFC of the
4-6
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CSI»OII?tOI
567 engine, these values correspond to about 50-80 lb PM/1000 gallons. Hydro-
carbons were also considerably higher, corresponding to about 100 lb/1000
gallons at maximum power.
The 567-series engine used in these tests incorporated older combus-
tion and injection technology, and this is the likely cause of the higher
emissions. Substantial reductions in locomotive smoke emissions due to im-
provements in engine technology have been documented (Kotlin and Williams,
1975). It is also possible that emissions from this laboratory 2-cylinder
engine may not have been completely representative of those from actual locomo-
tives.
Our "best-estimate" emission factors for locomotives are shown at the
bottom of Table 4-2. For gaseous emissions, the factors for switching and
line-haul duty cycles are taken directly from Ingalls (1985). For particulate
emission factors, we assumed that virtually all line-haul operation was per-
formed by relatively low-smoke modern locomotives such as the two 12-cylinder
engines tested at SWRI. Eighty percent of line-haul operation was assumed to
be by EMD locomotives, and 20 percent by GE locomotives.
For switching applications, we assumed that 50 percent of the fuel
consumption was by older, high-emitting engines, with the other half split 80
percent to EMD engines and 20 percent to GE engines. The older high-emitting
engines were assumed to emit about 60 lb of PM per 1000 gallons of fuel
consumed. The resulting composite PM emission factors are 13 lb/1000 gallons
for line-haul operation and 39 lb/1000 gallons for switching.
To combine the line-haul and switching-cycle en ission factors into
one overall factor, the values for the two cycles were weighted by the fraction
of fuel consumed in each type of operation—72 percent to line haul and 28
percent switching. These fractions were taken from Ingalls (1985), who used
the same fractions to weight emissions of HC, CO, and NO^ in developing his
composite emission factor estimates.
4-7
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BAR!*!!
4,3 Engine Pooulation and Emissions Inventory
¦¦*** j -1
I-
Table 4-3 presents fuel consfeption, population, and emissions
estimates for diesel-electric locomotives used in switching and line-haul
service. These estimates are calculated in two ways: for Class I railroads
only; and for all locomotive engines, including those operated by Class II and
III Railroads. Class I railroads are those having gross operating revenues of
$87.3 million or greater. These railroads account for about 90 percent of all
railroad revenues and 97 percent of ton-miles travelled (Assoc. of Am.
Railroads, 1986). Class II and III railroads are primarily switching and
freight-transfer operations connected with major ' cities and ports, or
short-line operations serving a limited geographic area. Because of their
concentration in and near major cities, the Class II and Class III railroads
include a disproportionate amount of switchyard operation, and may thus
contribute a larger fraction of the urban emissions.
Table 4-3a shows the fuel consumption, locomotive population, and
estimated emissions for Class I railroads. The total fuel consumption and
population data for this table are taken from the statistics of the Association
of American Railroads (1986), and are broken down into line-haul and switching
activities following an assumed 72 percent/28 percent split. The AAR fuel
consumption data do not include AMTRAK, so we added 60 million gallons for
AMTRAK fuel consumption (U.S. Department of Transportation, 1985) to the AAR
value. AAR locomotive numbers do include AMTRAK, so no adjustment was
necessary. Total emissions were calculated from total fuel consumption using
the "best estimate" emission factors from Table 4-2.
Table 4-3b shows estimates of the locomotive population, fuel
consumption, and emissions of Class II and III railroads. Locomotive
population data for these railroads were obtained by summing the numbers of
locomotives reported for these railroads by McDonald (1986). All Class II and
Class III railroad locomotives were assumed to operate in a switching cycle,
with annual fuel consumption per locomotive equal to that of switchers used by
Class I railroads.
4-8
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COIPOItllON
TABLE 4-3. POPULATION, FUEL CONSUMPTION, AND ESTIMATED
EMISSIONS FOR RAILWAY LOCOM3TIVES
Type
No.
Units
Annual
Fuel Cons.
(1000 Gal.)
HC
Emissions (Tons/Year)
CO NOx PM
(a) Class I Railroads
Line-Haul
Switch
Total
8,69 T
14.1702
22,869
1
2,307,287J
897,2783
3.204,5651
44,877
21,265
66,142
260,723
38,942
299,665
643,733
209,963
853,696
14,997
17,946
32,943
(b) Class II and III Railroads
Switch
3,236
204,911'
4.856
8,893
47,949
4,098
(c) All Railroads
Line-Haul 8.699 2,307,287 44,877 260,723 643,733 14,997
Switch 17,406 1,102,189 26,122 47,835 257,912 22,044
Total 26,105 3,409,476 70,999 308,558 901,645 37,041
DOE Fuel Cons. Est."
3,209,729
Sources:
*American Association of Railroads, 1986.
^Radian estimates.
3
Calculated front duty cycles in Ingalls (1985).
^McDonald, 1986.
^Energy Information Admin., 1985.
4-9
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For comparison, Table 4-3 also shows the DOE estimate of railway fuel
deliveries for 1985. This value was based on data obtained from the
^sociation of American Railroads, and thus compares well with the data on
Class I railroad fuel consumption taken from AAR statistics.
4.4 Emissions Test Cycle
Since locomotive engines operate in only a few well-defined operating
conditions, definition of an appropriate test cycle should be relatively
straightforward. The emission factors m Section 4.3 are based on two such
test cycles: one for line-haul operation and one for switching. These cycles
consist essentially of two different sets of weighting factors for the
steady-state emissions measured for each operating mode. Transient effects (if
any) are thus ignored. For line-haul operation, this is probably appropriate,
as the time spent in notch-to-notch transitions is small compared to the total
operating time. Switching duty involves much more transient operation,
however, and thus may not be adequately modeled by a steady-state test
sequence. This is a concern, since switching and transfer operation are
responsible for a large fraction of locomotive emissions in urban areas.
Further research to clarify this point is recommended.
In addition to the transient emissions question, the appropriate
weighting of different operating modes within each cycle, and of switch versus
line-haul operation, should be re-examined in the light of recent changes in
operating patterns. Qualitatively, railroads appear to be making more
efficient use of equipment, and to be shutting locomotives off more when they
will not be used for a seme time. Both of these trends should reduce idling
time, while increasing the time spent in notches 1-8 and dynamic brake.
Ingalls (1985) addressed these issues, but without data to resolve then.
Acquisition of actual current operating data would be needed to fully settle
this issue.
4-10
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RADIAN
«o*»«Rifiaa
4.5 Feasibility of Emissions Control
From the data presented in Section 3,2, it is clear fhat a substan-
rial reduction in locomotive emissions would be possible even with existing
technology. With additional R&D in the field, even larger emission reductions
could be expected. In this section, we consider two different levels of
emissions control for new engines: an intermediate level attainable in the
relatively short term (about 3 years), and relying essentially on existing
technology; and an advanced level requiring a longer period for research and
development. The first of these control levels is intended to be comparable in
stringency to EPA's 1988 standards for on-highway diesel engines, while the
second is intended to be comparable to the 1991 standards. The reader is
warned that these are engineering estimates only, based on very limited data,
and intended only to indicate the potential benefits of regulation in this
area. Additional research to confirm these estimates would be essential before
these or any other emission standards were incorporated into law.
Due to the engine manufacturer's practice of making new-technology
components available for rebuilding older engines, much of the
emissions-control technology discussed in Section 3.2 would be applicable even
to existing locomotives. Thus, in addition to new engines emission levels,
estimates of the feasible emissions control level for existing engines are also
presented. In most cases, achieving these levels would require rebuilding the
engine, at a cost of $80,000 to about $200,000, depending on the extent of the
modifications (Davis, 1986). This need not present a major barrier, however.
If the engine were being rebuilt anyhow, the additional cost due to the
emissions control modifications would be relatively small. Regulations to
require best-available control technology on new, rebuilt, or substantially
modified locomotives could be reasonable and practical, therefore.
Intermediate level controls—Feasible intermediate-term emission
controls for locomotive engines would include retarded injection timing,
cooling-system modifications to reduce charge air temperature, increased
4-11
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RfiRlfW!
injection pressure, and optimization of combustion chamber geometry, air flow,
and locomotive notch settings for reduced emissions. Based on the data pre-
T*
sentesfc in Section 3.2, we estimate that these modifications could reduce NO
x
emissions below 6.0 g/BHP-hr.
To ensure against an unacceptable increase in FM and HC emissions at
this low NO^ level, a regulatory cap on these emissions would be desirable.
Given the limited data available on PH emissions from these engines, the exact
PM level achievable at 6.0 NO is unknown. However, based on the PM data
x
described above, experience with the on-highway truck standards, and a rela-
tively less stringent steady-state test cycle for locomotives, a PM emissions
standard of 0.50 g/BHP-hr appears readily achievable. Based on Table 3-1, an
HC emissions standard of 0.50 g/BHP-hr also appears reasonable. The resulting
emissions standards and corresponding emission factors are shown in Table 4-4.
Advanced emission controls—Since so little research has been done on
medium-speed diesel emissions controls, the ultimate form of advanced mission
controls for these engines is difficult to project. Some technologies which
clearly could be applied, however, include electronically-controlled unit
injectors, reduced oil consumption, higher compression ratios, reduced initial
rate of injection, and further optimization of fuel-air mixing and combustion.
Vigorous application of these technologies should make possible a further
reduction in NO^ emissions to about 4-5 g/BHP-hr, together with lower PM
emissions. For this analysis, we assume levels comparable to the 1991 stan-
dards for on-highway engines, or 5.0 g/BHP-hr NO^ and 0.20 g/BHP-hr PM.
Levels of emission control well below these limits could conceivably
come about through the use of aftertreatment technologies (i.e. trap-oxidizers,
catalytic converters, or selective catalytic reduction), alternative fuels (CNG
or methanol), water/fuel emulsions and/or exhaust gas recirculation (EGR). EGR
in conjunction with a water/fuel emulsion has been shown to be an especially
effective emissions control technique for medium-speed engines (Wilson et al.,
1982). Further research to establish the effects of these technologies on
emissions and durability in actual locomotive engines is required, however.
4-12
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TABLE 4-4. ESTIMATED ACHIEVABLE EMISSIONS CONTROL STANDARDS
TOR LOCOMOTIVE ENGINES
Emissions
Limit
(g/BHP-hr)
Equivalent
Emission
Factor
(lb/1000 gal.)
New Engines
Intermediate Control Level
NOx
6.00
238
HC
0.50
20
PM
0.50
20
Advanced Technology
•
NOx
5.00
198
HC
0.30
12
PM
0.20
8
Existing EnRines (retrofit)
NOx
8.00
317
HC
0.50
20
PM
0.50
20
Source: Radian estimates.
4-13
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COIPBIJIf ION
Existing locomotives—Retrofit emission controls for existing locomo-
tives would generally resemble the intermediate-level controls described above.
T*
However, not all locomotive models would be equa?£y adaptable to low-emission
technologies, so some relaxation of the intermediate-level standards would be
desirable for existing engines. We recommend that this relaxation be in the
N0x standard, since over-reducing NO^ can cause large increases in PM and HC
emissions" and fuel consumption. Research would be required to identify the
control levels actually achievable, but a NO^ standard of 8.0 g/BHP-hr should
be high enough to avoid any major deterioration in fuel economy or PM emis-
sions .
4.6 Cost-Effectiveness Analysis
Table 4-5 presents seme very rough estimates of the
cost-effectiveness of controlling locomotive emissions. Two cases are
considered: the "intermediate" standards for new engines, and the suggested
retrofit standards for existing engines when they are overhauled. Both of
these involve relatively near-term technology. The uncertainty in the cost and
effectiveness of advanced-technology emission controls is too great to allow
for any realistic cost-effectiveness calculations.
Calculation of cost-effectiveness values where more than one
pollutant changes poses a difficult cost-allocation problem. The values in
Table 4-5 were calculated by allocating all the cost of control to the
reduction in HC and NO emissions, with no debit for the increase in PM.
x
Reductions in NO^ and HC are often combined in this way, since both pollutants
contribute to ozone formation. Since both the "new" and the "existing" engine
considered are turbocharged, with relatively modern technology, the major
effect of emission controls in each case is a reduction in NO , with a minor
x
reduction in HC and a small increase in PM. Application of similar standards
to an older (higher PM) locomotive would result in a PM decrease.
4-14
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TABLE 4-5. ESTIMATED CO ST-EFFE CTIVENESS OF EMISSIONS
CONTROL FOR NEW RAILWAY LOCOMOTIVES
New Engine
Existing Engine
EMISSION CONTROL COSTS
Initial Cost
Engine Life (yrs)
Amortized Cost/year § 10%
Fuel Cons. Increase
Annual Fuel Cons. (Gal)
Baseline
With controls
Added Fuel Cost @ $0.80/gal
Addl. Ann. Maintenance
Annualized Control Cost
Per Locomotive
$ 80,000
15
$ 10,518
5%
138,000
144.900
$ 5,520
$ 5,000
$ 21,038
$100,000
7
$ 20,541
3%
140,680
144.900
$ 3,376
$ 5,000
$ 28,917
EMISSIONS
Emission Factors (lb/1000 gal.)
Baseline
NOx
HC
PM
With Controls
NOx
HC
PM
523
32
14
238
20
18
533
41
20
238
20
20
Annual Emissions (tons/locomotive year)
Baseline
NOx 36.1
HC 2.2
PM 1.0
With Controls
NOx 17.2
HC 1.4
PM 1.3
37.5
2.9
1.4
17.2
1.4
1.4
Emissions Reduction (tons/locomotive year)
NOx 18.8
HC 0.8
PM -0.3
20.2
1.5
0.0
Cost-Effectiveness ($/ton)
NOx + HC
$ 1,073
$ 1,332
4-15
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RADIAN
COIPOIAVIOH
The data in Table 4-5 are based on rather high estimates of the costs
of treeting emissions standards for medium-speed engines. These reflect the
great cost of the engines themselves, the small sales volume (rediting in a
greater cost per engine for development and certification), and the small
amount of existing work on medium-speed engine emission controls. These values
are considered to be somewhat conservative (in the sense of over-stating the
cost of control)—actual costs per unit might well be less, but are considered
unlikely to be significantly more. Despite this, the estimated costs-per-ton
of NO^ + HC controlled are rather low compared to most other significant new
source of NO reductions. Thus, imposition of intermediate-technology emission
x
standards both on new locomotives and on existing locomotives when they are
rebuilt should be a highly cost-effective emissions control strategy.
4-16
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RADIAN
cotpoiivaoii
5.0 MARINE VESSELS
Marine vessels included in this^st^dy include diesel-powered tug and
towboats. passenger vessels, fishing vessels, and private recreational craft,
but not ocean-going ships. Worldwide, the vast majority oi ocean-going ships
(as well as most smaller non-recreational vessels) are now diesel powered, due
to -the superior fuel efficiency of the diesel engine. These ships are
doubtless significant contributors to the missions inventories m major port
cities such as Los Angeles or New York. For historical reasons, however, few
U.S.-flag ships are diesel powered. Access of foreign-registered ships
(including motorships) to U.S. ports is controlled by treaty, and would thus
not be subject to regulation by EPA, even if other off-highway vehicles were
made subject to such regulations.
5.1 Engine Characteristics and Operating Conditions
Except for those used in oceangoing ships, the diesel engines used in
marine vessels are primarily high-speed engines from Groups 2 and 3, or
medium-speed engines classed in Group 1. High-speed engines are used as the
main propulsion in smaller craft, and for electric generation on larger
vessels. Vessels such as pleasure craft, fishing boats, small workboats, and
similar vessels are typically powered by Group 2 engines similar to those used
in highway trucks. The larger Group 3 engines are used in many tugboats,
towboats, and similar vessels.
Many of the smaller high-speed marine engines in use are
naturally-aspirated, and the turbocharged ones may or may not be equipped with
intercoolers. Most of the more powerful Group 2 engines and most Group 3
engines in marine applications are turbocharged and aftercooled, however. To
increase power output still further, some engines in this group use
low-temperature aftercooling, cooling the heat exchanger with water pumped from
5-1
-------
overside. However, many engines in this class still use jacket water
aftercooling, due to t..e possible corrosion problems involved (especially with
sea-water).
Host high-speed diesel engines in marine service in the U.S. were
built by Detroit Diesel Allison, Caterpillar, or Cummins. The majority of
these engines are equipped with direct injection combustion systems, and most
use unit injectors. IDI engines in marine use include the Caterpillar
300-series and a few light-duty engines used mostly in pleasure craft. The
300-series IDI engines have been superseded in Caterpillar's product line by
the direct-injected 3500 series. They were extremely popular marine engines,
however, and many remain in use.
Main propulsion for most large, powerful working vessels such as
large tugboats, river towboats, and offshore oil supply vessels is provided by
locomotive-derived medium-speed engines such as the EMD 567 and 645 series and
Aleo locomotive engines. These engines are identical in every major respect to
the similar-model engines used in locomotives. Still larger medium-speed
engines, specifically designed for marine service, power Great Lakes freighters
and similar vessels, including many oceangoing ships. Slow-speed diesel
engines are used only in large ocean-going ships, where their very low
rotational speed allows thea to be direct-coupled to the propeller. As this
report does not deal with ocean-going ships, slow-speed engines will not be
discussed further.
High-speed and medium-speed diesel engines used for vessel propulsion
are normally coupled to the propellers through a set of reducing gears or
"marine transmission", which provides forward and reverse motion, but only one
reduction ratio. The engine speed is thus a constant multiple of the propeller
speed, while the engine power output is determined by the propeller's power
absorption curve. The vessel's helmsman controls the engines through a set of
"throttles", which change the engine speed setpoint of a constant-speed
5-2
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RADIAN
coa»os«Tio«
governor. For a given "throttle" position, therefore, the engine RPM (and thus
propeller RPM) is held constant,- and the governor adjusts engine power output
as needed to maintain this RPM setting.
Propeller power absorption increases as the cube of the rotational
speed. Thus, if the engine and propeller are properly matched, maximum engine
power is produced only near the engine's rated speed, and the power required
drops off rapidly as RPMs are reduced. Much of the engine's operating time,
and most of the BHP-hr produced occur in "cruise" mode. Typical "cruise" RPM
is about 80-95 percent of rated speed, corresponding to about 40-80 percent of
maximum power. Like locomotive engines, marine engines also spend a great deal
of time idling. This is due to the inconvenience of starting Large diesel
engines when cold, and to the need to have engine power available at short
notice under many conditions.
In addition to their main propulsion engines, larger marine vessels
use smaller, high-speed diesel engines to drive generators for electrical
power. These engines (typically Class 2 or Class 4) are governed at
synchronous speed, which is normally 1,800 RPM for U.S. vessels. To provide
electric power as needed, they generally run continuously, even when the vessel
is docked, moored, or otherwise temporarily inactive. Since these engines are
sized to handle the maximum expected electric power demand, they run most of
the time under rather light load. Unlike engines used for mam propulsion,
generator engines tend to be naturally aspirated, and have relatively high NO^
emissions as a result.
5.2 Current Emission Factors
Reliable emission factors for marine vessels equipped with either
high or medium-speed engines are unavailable. While snission factors for these
vessels are listed in EPA's AF-42 compilation of emission factors, a review of
the derivation of these factors (Ingalls, 1985) showed that they were computed
incorrectly, and that they are based on a narrow range of engines which is no
5-3
-------
oi»«*a?i«M
longer representative of those in use. In addition, AP-42 provides no data on
particulate emissions from marine engines. Thus, we were forced to develop our
own estimates of emission factors for high-speed and medium-speel ^esel
engines in marine use.
The emission factors developed in this report are intended to
represent composite emissions over the entire engine duty cycle, for a broad
range of engine horsepower ratings. AP-42, on the other hand, presents
separate emission factors for each operating mode, and divides them into a
number of rather narrow horsepower ranges. For these reasons, no direct
comparison of the Radian and AP-42 emission factors is possible.
The great majority of medium-speed diesel engines in marine use in
the U.S. are essentially seagoing locomotive engines. Since the emission
factors for locomotives are reasonably well defined, and since the duty cycle
for marine engines is not too dissimilar from that of locomotives, it was
decided to apply the "best estimate" emission factors developed for locomotives
to medium-speed marine engines as well. These factors (which are listed in
Table 5-1) are the same as the composite of the line-haul and switching duty
cycles listed in Table 4-3.
Emission factors for high-speed diesel engines in marine service are
also listed in Table 5-1. These values are Radian estimates, based in part on
the data used in developing the AP-42 emission factor estimates (Engineering
Science, 1984) and partly on other data sources (Dowdall, 1987; Santa Barbara
APCD, 1987). The particulate emissions factors were based primarily on
measurements in uncontrolled heavy-duty truck engines, (Weaver, et. al., 1984)
which may not be fully applicable in this case. All of the factors shown
should be considered only very rough approximations—acquisition of better data
through actual testing is strongly recommended.
5-4
-------
TABLE 5-1. ESTIMATED CURRENT EMISSION FACTORS FOR DIESEL
ENGINES USED IN MARINE APPLICATIONS
EMISSION FACTORS
g/BHP-hr lb/1000 gal,
High Speed Engines
HC
CO
NOx
PM
0.8
3.0
11.0
0.6
32
119
436
24
Medium Speed Engines'1
HC
CO
NOx
PM
1.0
4.7
13.4
0.5
41
187
533
20
Sources:
1Radian estimate.
2
From Table 4-2.-
5-5
-------
RADIAN
eeiPDiafian
5.3 Engine Population and Emissions Inventory
Table 5-2 lists the estimated population and "**nationwide fuel
consumption data I or the major classes of diesel powered, non-oceangoing
vessels m use in the U.S. These estimates should be understood as being very
approximate—data on marine vessel populations and usage in the U.S. are
fragmented, incomplete,, and occasionally contradictory. Table 5-2 was patched
together from 9 independent sources. We relied most heavily on the Army Corps
of Engineers Suamary of U.S. Flag Passenger and Cargo Vessels (Army Corps of
Engineers, 1983). This report does not include all relevant vessels, however.
Data on the number of fishing and pleasure craft were obtained from other
sources.
The breakdown of the total horsepower shown in Table 5-2 into
high-speed and medium-speed engines is based on only very limited data.
Descriptions of the engines and horsepower ratings for tug and tcwboats are
given in the Inland River Record (Owen, 1986). Analysis of a sample of these
boats showed that only 20 to 25 percent of these boats are powered by
medium-speed engines, but that these engines are responsible for about 60
percent of the total horsepower for the group. Extrapolating from this limited
information, we estimated that about 60 percent of dry cargo and/or passenger
ship horsepower, 50 percent of ferry horsepower, and 20 percent of commercial
fishing craft (over five tons) horsepower are generated by medium speed
engines.
Table 5-2 shows an estimate of the total annual fuel consumption by
each class of marine vessels. These were calculated from the engine load
factors and annual usage shown in the table, and an assumed fuel consumption of
0.4 lb/BHP-hr. The load factors and annual usage values shown are Radian
estimates, based on typical operating patterns for each class. These values
are only rough approximations, as actual data on load factors and hours of
operation are lacking.
5-6
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TABLE 5-2. ESTIMATED NATIONWIDE POPULATION AND EMISSIONS FROM DIESEL ENGINES USED IN MARINE APPLICATIONS
Total
Ann, Fuel
EMISSIONS
(TONS/Yj?)
Diesel
Horsepowe r
Load j
Usage
Consumption
Vessels
(1000s)
Factor
(Hr/Yr)
(1000 gal)
HC
CO
NO#
PM
Dry Cargo/Passenger
1 2
1.893
3 4
* 5,494
457,833
8,561
36,581
113.131
4.945
High-Speed
2,198
50%
3,000
183.133
2.930
10,896
39.923
2.198
Medium-Speed
3.296
50%
3,000
274.700
5.631
25,684
73.208
2.747
1 2
Towboats and Tugboats 5,418 "
7,988
798,800
15,177
65,635
199.966
8,521
High-Speed
3.195
50%
3,000
266,267
4,260
15,843
58,046
3,195
Medium-Speed
4.793
50%
4,000
532,533
10.917
49,792
141.920
5.325
Railroad Ferries
107 *
262
11,644
223
970
2.934
123
High-Speed
79
40%
2,000
3,493
56
208
762
42
Medium-Speed
183
40%
2,000
8.151
167
762
2.172
82
General Ferries
1 2
1.000 •
1,000
44. 444
811
3,400
10.767
489
High-Speed
500
40%
2,000
22.222
356
1,322
4.844
267
Medium-Speed
500
40%
2,000
22.222
456
2,078
5.922
222
Fishing Craft
115,800;!**
24,400
423,333
7.133
27,908
96.167
4,920
> 5 Net Tons
24,000
12.000
320.000
5.480
21.760
73.640
3.680
High-Speed
9,600
30%
1,500
240.000
3.840
14,280
52.320
2,880
Medium-Speed
2,400
30%
2,000
80,000
1.640
7,480
21.320
800
< 5 Net Tons
, '
High-Speed
91,800 *
12.400
30%
500
103,333
1.653
6,148
22.527
1.240
Pleasure Craft
1 7
Hi gh-Speed
97,000 '
17.500
50%
200
97,222
' 1,556
5,785
21.194
1,167
Total
221,218
56.644
1,833,278
33.462
140,279
444,158
20,164
High-Speed
218,718
45,471
915,671
'14,651
54,482
199.616
10,988
Medium-Speed
2,500
11.173
•
917,607
18.811
85.796
244.542
9,176
DOE Fuel Cons. Estimate
1,894,265
^Radian estimate.
Including an estimate of
unreported craft (Crowell,
1986).
3
^U.S. Army Corps of Engineers, 1983.
^.U.S. Maritime Administration, 1983.
National Marine Fisheries Service, 1984.
Jjohn 01Donnel1, 1986.
Moyat, 1986.
-------
BfiRMM!
Total fuel consumption by all classes shown in che table is
approximately 1.8 billion gallons per year. A DOE report (Energy Information
Administration, 1985) showing the total consumption of distillate fuel oil for
vessel bunkering at about 1.9 billion gallons, served to calibrate our
estimate. The two numbers are not strictly comparable, since the DOS value
includes distillate fuel consumed by oceangoing ships. These ships burn
primarily residual fuel oil, but sane use a certain percentage of distillate
fuel oil as well. This is offset to soma degree by the fact that some
non-oceangoing vessels can use residual oil or distillate/residual blends.
One other source of information on marine fuel consumption was
located. Based on the results of a national freight transportation model,
Argonne Laboratory (Millar et al., 1982) estimated total energy consumption for
tugs and towboats in the U.S. at about 147 trillion BTU, or slightly over 1
billion gallons of diesel fuel equivalent. Even considering that this value
includes same non-diesel energy consumption, this is somewhat higher than the
estimates in Table 5-2.
Estimates of pollutant emissions from the various types of marine
vessels are also presented and totaled in Table 5-2. These estimates were
arrived at by multiplying the emission factors in Table 5-1 by the fuel
consumption data calculated in Table 5-2.
In terms of regional distribution, 55 percent of dry cargo and/or
passenger ships are located on the Mississippi and Ohio Rivers, 35 percent
along the U.S. coastline, and the rest are situated on the Great Lakes. A
considerably different situation exists for railroad ferries where 90 percent
are located on the coastline with the remainder on the Great Lakes. For
towboats and tugboats, the percentages are 31 percent. 66 percent, and 3
percent for the coastal areas, inland waterways, and Great Lakes, respectively
(U.S. Army Corps of Engineers, 1983). These thcuc statistics indicate that a
large percentage of domestic vessels operate on the Mississippi and Ohio
5-8
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COIPOIIf IBM
Rivers, Since the Mississippi and Ohio Valleys and lower Great Lakes region
are cue of the densest clusters of urbanized areas in the United States, the
impact of these emissions on humans could be significant.
Fishing and pleasure craft, on the other hand, are located
predominately along the U.S. coastline. The only major inland concentration of
fishing craft is on the Chesapeake Bay, which accounts for 21 percent of
fishing craft (National Marine Fisheries Service, 1984). Likewise, most
inboard pleasure craft are operated on the coasts with the Great Lakes being
the only major inland concentracion. About 25 percent of these boats are
operated on the great lakes (Cmdr. Scarborough, 1986).
5.4 Emissions Test Cycle
Relatively little investigation of marine engine duty cycles has been
performed. From the few studies which have been done (e.g., Santa Barbara
APCD, 1987), as well as discussion with vessel operators, it is clear that most
of the fuel burned in marine operations is burned in cruise mode, with vessel
maneuvering and idle making fairly minor contributions. Idle does account for
a very significant fraction of the operating time, however, which suggests that
it could be ait important contributor to HC and PM emissions. Full-speed,
full-load operation may also contribute significantly to PM emissions, since
sane vessels "cruise" at full power. Due to the dominance of steady-state
operating modes, transient effects on emissions are probably negligible.
These facts suggest that an appropriate test cycle for marine
propulsion engines could consist of four steady-state operating modes: idle,
light load/low RPM, "cruise", and full load, with cruise and idle weighted most
heavily. For generator engines, a single-speed, multi-power level test cycle
(e.g. 2, 25, 50, 75, and 100 percent load at 1800 RPM) would give the most
realistic representation of in-use conditions.
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DADIAM
CO«POlAfl91
5.5 Feasibility of Emissions Control
Estimates of achievable emission standards for diesel engines used in
marine applications are shown in Table 5-3. For new engines, two levels of
emissions control are considered. The "intermediate" control level is intended
to correspond in stringency to the 1988 on-highway emissions standards, while
the "advanced technology" level corresponds to. the standards scheduled for
1991. In addition, Table 5-3 shows our estimates of achievable retrofit
emission control standards for existing medium-speed and large high-speed
engines. Again, the reader is warned that these are engineering estimates
only, based on very limited data, and intended only to indicate the potential
benefits of regulation in this area. Additional research to confirm these
estimates would be essential before these" or any other emission standards were
incorporated into law.
High speed engines
Intermediate control level—High-speed engines are used both for
propulsion and as "prime movers for electric generation. Although the duty
cycles for these two types of operation vary somewhat, the applicable emission
control technologies are essentially the same. At the intermediate control
level, these technologies include: turbocharging with low-temperature
aftercooling; increased boost pressure; retarded injection timing (with timing
advanced at light loads to reduce HC and PM emissions); and changes in airflow,
fuel injection, and combustion chamber design to minimize emissions. These
technologies have all been well demonstrated in on-highway engines, and the
combination of high boost pressure with low-temperature aftercooling has seen
increasing use in marine main propulsion engines as well. Application of these
technologies across the board should be straightforward, therefore. The
emissions levels achievable with these technologies should be comparable to the
1988 standards for on-highway diesels. This is reflected in Table 5-3.
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coaooaaTioM
TABLE 5-3. ESTIMATED ACHIEVABLE EMISSIONS CONTROL STANDARDS
FOR MARINE DIESEL ENGINES
life
Equivalent
Emissions
Emission
Limit
Factor
(g/BHP-hr)
(lb/1000 gal.)
HIGH-SPEED MARINE ENGINES
Intermediate Control Level
NOx
6.00
238
HC
0.50
20
PM
0.50
20
Advanced Technology
NOx
5.00
198
HC
0.50
20
PM
0.25
10
Existing Engines Over 300 HP
(retrofit)
NOx
8.00
317
HC
0.50
20
PM
0.50
20
MEDIUM-SPEED MARINE ENGINES
Intermediate Level
NOx
6.00
238
HC
0,50
20
PM
0.50
20
Advanced Technology
NOx
5.00
198
HC
0.30
12
PM
0.20
8
Existing Engines (retrofit)
NOx
8.00
317
HC
0.50
20
PM
0.50
20
Source; Radian estimates.
5-11
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nrapiNii
C O ¦ » O ¦ • T I O «
Advanced technology—The list of possible advanced emission control
t ,'chnologies for marine engines is essentially the same as the list of
intermediate control technologies, with the possible addition of electronic
tuning controls. Exhaust gas recirculation would probably be ruled out for
marine engines, due to its possible impact on engine reliability; while
catalysts and trap-oxidizers would likely be ruled out by fire-safety
considerations. The emissions standards in Table 5-3 reflect these
limitations. The PM level of 0.25 g/BHF-hr shown for the "advanced technology"
standards—while numerically identical—is actually somewhat more lenient than
the 1991 PM standard for on-highway vehicles. This is due to the fact that PM
for marine vessels would be measured in steady-state operation, while the
on-highway standard is based on a highly transient operating cycle.
Retrofits—As with locomotive engines, high-horsepcwer marine engines
are commonly upgraded to current technology levels when they are overhauled,
and they can achieve an indefinite lifespan through repeated overhauls. Thus,
as with locomotives, it would make sense to consider requiring retrofit of
emissions controls to these engines. The major changes required would be the
pistons, injectors, and camshafts, (most or all of which would be replaced in
any event), plus possible changes in the turbocharger and aftercooler system.
Since the engine would already be dismantled for overhaul, the added cost of
these changes would be relatively small. For cost-effectiveness reasons, it
would be desirable to limit this requirement only to the larger engines, which
tend to see more intensive use. For our purposes, we have drawn the line
arbitrarily at 300 HP, but further research to determine an appropriate level
is recommended.
Medium-speed engines
The estimates of achievable emissions control levels for
medium-speed engines in marine service are identical to the estimates
previously presented for locomotive engines. The modifications required to
5-12
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!I»!AN
these engines would also be essentially the sane as those required for
locomotive engines: upgrading engine compo lents, retarding injection timing.
f
increasing the injection rate, and modifying t®he engine cooling system to
provide low-temperature aftercooling. Due to the availability of the ocean as
a heat sink, this last modification would be easier and less expensive for
marine engines than for locomotive engines.
5.6 Cost-Effectiveness Analysis
Table 5-4 shows sane very rough calculations of the
cost-effectiveness of emissions control to the "intermediate" level for new
diesel engines of three types: medium-speed and high-speed main propulsion
engines, and a high-speed generator engine. While they are very rough and
approximate, these calculations give some idea of the potential
cost-effectiveness of controlling these engines, compared to other sources of
potential emission reductions. As with locomotives, cost-effectiveness is
calculated based on the reduction in NO and HC emissions, and no credit or
x
penalty is taken for PH emission changes. No cost-effectiveness estimates were
made for "advanced technology" emission controls or for retrofits, due to the
uncertainty (and, for retrofits, the great variability) of costs in these
cases.
For the medium-speed engine, the costs of emission control assumed in
these calculations are less than those assumed for a similar engine in
locomotive service. This is due primarily to the lower costs assumed for the
low-temperature aftercooler. In a locomotive, this would require an air-air
aftercooler or a large separate air-water heat exchanger, either of which would
be difficult to engineer into the limited space available. In marine
operation, an effectively infinite heat sink is available in the water close
overside, so that the cost of low-temperature aftercooling would be relatively
small. Maintenance costs would also be lower, due to the absence of the
air-air heat exchanger and the less intensive use. The other costs assumed for
this intermediate control level are primarily design, development, and
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COIVO*AT tOM
TABLE 5-4. ESTIMATED COST-EFFECTIVENESS OF EMISSIONS CONTROL
FOR DIESEL ENGINES USED IN MARINE APPLICATIONS
Main Propulsion Engines
Mediua-Speed
High-Speed
Generator
Engine.
EMISSION CONTROL OOSTS
Engine Horsepower
2,500
500
200
Initial Cost
$50,000
$3,000
$1,000
Engine Life (yrs)
20
15
15
Amortized Cost/year @10%
$5,873
$394
$131
Fuel Cons. Increase
52
5%
5%
Annual Fuel Cons. (Gal)
Baseline
160,000
12,500 '
16,000
With controls
168,000
13,125
16,800
Added Fuel Cost 0 $0.80/gal
$6,400
$500
$640
Addl. Ann. Maintenance
$3,000
$200
$200
Annualized Control Cost
$15,273
$1,094
$971
Per Engine
EMISSIONS
Emission Factors (lb/1000 gal.)
Baseline
NOx
523
436
436
HC
32
32
32
PM
14
24
24
. With Controls
NOx
238
238
238
HC
20
20
20
PM
18
20
20
Annual Emissions (pounds per
engine per year)
Baseline
NOx
83,680
5,450
6,976
HC
5,120
400
512
PM
2,240
300
384
With Controls
NOx
39,984
3,124
3,998
HC
3,360
263
336
PM
3,024
263
336
Emissions Reduction (pounds
per engine per year)
NOx
43,696
2,326
2,978
HC
1,760
138
176
PM
(784)
38
48
Cost-Effectiveness ($/ton)
NOx + HC
$672
$888
$616
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RADIAN
csa»oa*iisi
certification costs, which (while large) would be spread over a large number of
marine and locomotive engines. The additional manufact arixig costs of
refinements in injectors, combustion chambers, injection timing, etc. are
relatively small.
For the two high-speed engines, the approximate emission control
costs shown were based on existing technology for on-highway truck engines.
Technologies assumed were: turbocharging (for engines that don't have it
already), low-temperature aftercooling, retarded injection timing, increased
boost pressure, and optimization of combustion chamber and injector
characteristics. The major costs in this package are for the turbocharger and
aftercooler, and the design and certification costs for the engine. These were
assumed to be fairly high, as the marine market is limited, and Coast Guard and
American Bureau of Shipping regulations pose a formidable barrier to new
technologies.
As Table 5-4 indicates, the potential cost-effectiveness of emissions
control for new marine engines is about $600-$900 per ton. This is quite
attractive when compared to the costs per ton for other available NO^ and HC
reductions.
5-15
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coavoiifi§n
6.0 FARM EQUIPMENT
Self-powered farm equipment incudes tractors, combines, mowers, and
other self-propelled machinery used in agriculture. 1 For the last 20 years, the
engines used in these' vehicles * have been "overwhelmingly diesel, and they are
responsible for most diesel fuel consumption on farms. Engines in non
self-propelled equipment such as irrigation pumps, engine-driven blowers,
conveyors, etc. are responsible for a relatively small fraction of total fuel
consumption and emissions, and are not discussed here.
6.1 Engine Characteristics and Operating Conditions
The largest group of agricultural diesel engines are those used in
tractors. Tractor engines tend to be naturally-aspirated, ' direct-injected.
4-stroke engines of moderate speed and power output .(15-180 HP)* and'four to six
cylinders» Engines used in small' utility? tractors are primarily Group 4
engines of 15-50 HP ~and*rJapanese manufacture. Similar' engine's are also used in
lawn .and garden equipment. Larger tractor engines in the 40-180 HP range are
often produced^by_„the tractor » builder'.: and are specifically*, designed for
tractor;use. In addition to supplying motive power, these engines are often an
integral part of the structural framework of the tractor, with specially
reinforced oilpans and engine blocks to carry the structural load. These
engines are classed in Group II, and a number of thai have been adapted for use
(in a non-structural role) in highway trucks as well. Examples include the
John Deere 300 and 400-series engines and the Ford 6-cylinder diesel engines.
Recent years have shown an increasing trend to higher tractor power
rating and tractors of 400 HP and above are now available in four wheel drive
tractors. These high-powered engines are generally adapted.: froa-those "used in
on-highway^ trucks, and are often... turbocharged and intercooled, for increased
output (Implement and Tractor. 1986). Truck-type engines have also seen
increasing use m smaller tractors, with makers such as Perkins and Isuzu
supplying engines to tractor makers such as Massey Ferguson and White.
6-1
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COIVOKTIOM
Tractors undergo a varied and rigorous duty cycle. In addition to
plowing, planting, cultivating, hay baling, and other heavy agricultural work,
tractors are used for mowing, pulling wagons, front-end loading, dri^ng fence
posts, blowing snow, bulldozing, and even light earthmoving jobs. The smaller
utility tractors, as their name implies, tend to see a greater' variety of
applications, while the larger and more powerful tractors are primarily used
for heavy field work.
Combines, windrowers, • cotton, pickers," and other specialized
non-tractor agricultural equipment undergo a less varied duty cycle. Engines
for these vehicles are often equipped with medium-heavy duty truck engines such
as the Navistar DT 466 and the Caterpillar 3208. These may be
naturally-aspirated or turbocharged. In other cases, adaptations of tractor
engines or (in a few cases) specially-designed engines are used.
A weighted average of Harvest Publishing's 1985 Tractor Survey, the
largest number of tractors in use were made by John Deere and International
Harvester, both of which had produced above approximately 27 percent of the
total. Other significant tractor manufacturers include Massey Ferguson, Ford,
Allis-Chalmers, White, and J.I. Case, all of whom had produced from 7 percent
to 10 percent of the tractors in use. Historically, John DeereT International,
Ford, and Case have produced their own tractor engines,* while Massey Ferguson,
Allis.^and White tend to use purchased engines.
The agricultural equipment operations of J.I. Case and International
Harvester were recently merged, and new. tractors produced by Case-IH will
presumably be designed around the "B" and" "C"' engines.*"produced by Case and
" Cummins in a joint venture arrangement. These engines ~are:'alscT targeted for.
the light-heavy and medium-heavy truck markets*.
6.2 Current Emission Factors
The best data on emission factors for farm equipment are contained in
a report to the California Air Resources Board by Environmental Research and
6-2
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RADIAN
Technology (ERT) (1982). This report was sponsored by the farm equipment,
construction 'equipment, and engint industries through their respective
association ST"*and 'summarizes massive amounts of manufacturer-supplied data.
Although the report deals specifically with California, the emission factor
data contained in it are the best available for remainder of the U.S. as well.
These data are presented in Table 6-1.
• The_ data, in. the ERT report.'suffer, from several limitations. The most
important of these is the absence^ofTparticulate measurements. As a result,
the PM emission factors in Table 6-1 were taken from"AP-42 (EPA, 1985). These
factors are based on emissions measurements on a limited sample of farm and
construction equipment engines tested at Southwest Research in the early 70's
(Hare et al., 1975). In c eminent s on our Task One interim report, the Engine
Manufacturer's Association (EMA)"criticized our_use of these factors, stating
that they are' no longer representative of farm and construction equipment
today (Young, 1987). This criticism has some, validity, especially for the
larger truck-derived engines used in higher-powered"equipment. No examples of
these engines were tested in the SWRI program, and it is not clear that the
emission factors developed for the smaller engines are appropriate here. As a
result, we" have" substituted* a*.*value of 0.80 g/BHP-hr (based on pre-control
particulateV'emissiens ?;_f~r on* heavy-duty; truck engines) forthe, EPA^ temission-^
factor for four-wheel drive tractors.
For two-wheel drive tractors and other agricultural equipment, we
elected to* retain "the EPA on is s ion factors. While it is true that many of the
specific engine models tested by Hare et al. are no longer in use, there is
little evidence to suggest that the new engines that replaced them are any
cleaner, and no more recent emissions data are available. Research"to obtain
more recent and_ applicable emissions data is strongly recommended.
Another limitation of the ERT data is that they are based on an
adaptation of the old 13-mode steady-state test cycle," and thus do not account
6-3
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CO! ¦€»¦ *VIO«
TABLE 6-1. EMISSION FACTORS FOR FARM EQUIPMENT
EMISSION FACTORS (G/BHP-HR)
HC1 CO1 NOx1 PM2
Equipment Type
Tractor, 2WD 100+ HP
1.84
4.23 '
11.59
1.28,
Tractor, 4WD
0.89
3.28
10.98 '
G.80"
Tractor, 2WD, 20-90 HP
2.16
6.42
10.94
1.28
Combines, Self-propelled
1.90
3.25
13.36
1.51
Windrower, Self-propelled
2.21
6.85
10.50
1.51
Field Forage Harvesters
0.96
2.84
9.98
1.51
Cotton Pickers
2.23
3.78
* 7.78
1.51
Cotton Sprayers
2.23
3.78
7.78
1.51
Orchard Sprayers
2.23
3.78
7.78
1.51
Compact Loaders
1.13
4.29
9.69
1.51
Fuel-Weighted Emission Factors
•
lb/1000 gal
72
182
456
50
g/BHP-hr
oM- 1,81
4.59
11.50
1.25
Sources:
^RT, 1982.
2EPA, AP-42, 1985.
3
Radian estimate.
6-4
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HARfAN
for any transient effects. This is also true of the PM data developed by Hare
et al. This is not a problem for most categories of farm equipment, since
• r
combines, windrowers, large' tragfors, etc., tend to be used primarily in nearly
steady-state operation. It may be a problem for the smaller tractors, however,
as these units tend to experience a fair amount of cyclic operation, and it is
certainly a problem for the compact loaders. This issue is discussed further
in Section 6,4.
Table 6-1 also shows a set of "fuel"weighted" emission factors for
farm equipment. These are simply the average of the emission factors for each
equipment class, with each class' contribution' weighted by its estimated
fraction of total diesel fuel consumption by farm equipment. The estimates of
diesel fuel consumption by each class are shown in Table 6-2.
6.3 Engine Population and Emissions Inventory
Reasonably complete information on farm equipment populations and
emission characteristics" is available. Population data are available in
numerous statistical summaries of the agriculture sector, and in estimates
developed by the Farm Implement and Equipment Institute, the industry
association. Table 6-2 shows our estimates of total populations, usage, fuei
consumption, and emissions,* for the major classes of self-propelled farm
equipment. These estimates are based on FIEI7.'revisions to USDA" population
numbers, and to the ERT estimates of average horsepower and hours of usage per
year (Young, 1987). As the table indicates, the great bulk of agricultural
equipment emissions—accounting for about 85 percent of, the total—are due to „
tractors, with combines, the only other major source.
Table 6-2 includes an estimate of the total nationwide fuel consump-
tion by agricultural equipment, calculated from the FIEI data and assuming fuel
consumption of 0.4 lb/BHF-hr. Also shown in the table is the Department of
Energy's estimate of total distillate fuel deliveries in the agricultural
sector for 1985. This value is closely comparable to the value calculated from
the FIEI data.
6-5
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TABLE 8-2. ESTIMATED POPULATION, RJEL CONSUMPTION, AND
EMISSIONS FROM DIESEL ENGINES USED IN FARM EQUIPMENT
»
Annual
Fun I
Total ^ Pcnt.g Diesel Usage g A*9*3 Lcetl 3 ConsumPtlDn EMISSIONS (TONS/YEAfl)
Equipment Type Population OieBal Population (hr/yr) H.P. Factor (1000 Gall HC CO NDx PM
Tractor, 2HD 100+ HP
865,700
94X
813,758
410
141
0.55
1,437,438
/ 52,432
120,538
330,282
30,474
Tractor, 4W0
85,475
- 100X
85,475
530
227
0.64
365,835
8,451
23,774
78,588
5,799
Tractor, 2WD, 20-90 HP
3,597,501
7051
2,518,251
300
50
0.34
799,125
34,218
101,704
173,308
20,277
Conbinae, Self-propelled
500,000
75X
375,000
220
138
0.58
349,067
13,148
22,489
82,449
10,449
Windrower, Self-propelled
110,000
20X
22,000
418
75
0.55
21,074
923
2,882
4,387
831
Field Forego Harvesters
9,500
100*
a.soo
390
150
0.78
24,083
458
1,358
4,765
721
Cotton Pickers
20,000
70S
14,000
353
115
0.55
17,388
788
1,301
• 2,8'B
620
Cotton Sprayers
2,700
70S
1,890
230
955
0.50
1,147
51
88
,-7
34
Orchard Sprayers
20,629
1036
2,063
100
70
0.35
281
18
21
43
8
Compact Loaders
113,400
23X
26,082
320
37
0.37
8.34B
142
840
1.219
190
TOTAL
3,888,019
3,021,581
108,803
274,869
8aB,B74
75,103
DQE/EIA Fuel Cons. Estimate
3,181,338®
gFIEI adjustments to USDA (1985) (Young, 1887].
gFIEI eat 1matea (Young, 1SB7).
^FIEI adjustments to EHT (1882),
Calculated assuming fuel consumption of 0,4 Ib/BHP-hr.
^Radian estimate.
Energy Information Admin., 1985.
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RADIAN
coaooaan on
"Almost by definition, farm equipment emissions are concentrated in
rural areas. Although some farming often occurs even, in highly urbanized
regions, such as the Scfeth Coast Air Basin of California, diesel farm equipment
for only 0.25 percent of the NO^ inventory in the SCAB. For comparison, in the
heavily agricultural Fresno area (which, like the SCAB, is not in attainment of
the Federal ozone standards) diesel farm equipment accounts for about 6 percent
of the NO^ inventory. These estimates were obtained by adjusting similar
figures for gasoline and diesel-powered equipment (Ingalls, 19855 to reflect
only diesel engine-pcwered equipment.
Using regional sales figures from the July 1985, Petroleum Marketing
Monthly (EIA, 1985), a good national distribution of farm equipment emissions
can be determined. It should be recognized that this distribution is based on
the premise" that agricultural sector fuel sales and engine emissions are
similarly related in all regions of the country. Using this tack, the New
England states account for .4 percent of farm related emissions, Mid-Atlantic
states account for 2.8 percent and, the rest of the eastern seaboard states
make up 8.4 percent. The Midwest accounts for a lion's share 49.2 percent of
farm generated pollutants. The South and Northwest add another 16.7 percent
and 6.0 percent, respectively, to the farm emissions total. Finally, the West
is responsible for the remaining 16.5 percent.
6-4 Emissions Test Cycles
As noted in Section 6-2, most types of self-propelled farm equipment
are used in essentially steady-state operation. For combines and other
specialized equipment, the engine generally experiences only a very limited
range of operating conditions. For tractors, the range of operating aconditions
is ' larger, varying from high-speed, low load running in light tasks to
sustained near-full power output in heavy work. Foremost tasks, however, the
engine speed and power requirements do not vary greatly from second to second,
so that a steady-state test cycle would probably be adequate for measuring
emissions. Although tractors in field operation do experience sane cyclic
operation (when turning at the end of a row, for instance) these cycles are
6-7
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RADIAM
coa voa «tio h
7.0 CONSTRUCTION AND INDUSTRIAL EQUIPMENT
T*
Construction equipment includes earthmoving and relasfed machinery
such as bulldozers, graders, scrapers, loaders, cranes, backhoes, and
off-highway trucks. Industrial equipment such as front-end loaders and
industrial tractors is also included in this category, as are specialized
mining and logging machines such as log skidders.
7.1 Engine Characteristics and Operating Conditions
K Diesel engines used in construction and industrial equipment (CIE)
range from less than 40 HP for forklifts and small loaders to more than 800 HP
for the largest earthmoving machines and off-highway trucks. rMost CIE engines
are relatively small, naturally-aspirated, moderate-speed engines classed in
Groups 2 and*4. Many of these are generally specially designed for their
applications, or adapted from engines used in small agricultural tractors. The
larger engines used in large earthmoving and similar machinery are less
numerous, but—due to their high power output and greater utilization—account
for a significant fraction of the total emissions from this category. These
engines are classed in Groups 2 and 3, and are often adapted from truck engine
designs (or vice versa). Many of these larger engines use turbocharging and
(sometimes) intercooling to increase their power output.
Usage patterns in construction and industrial equipment engines are
as varied as the equipment types themselves. Hydraulic pumps to power the
booms, lifts, buckets, blades, and other implements are a large part of the
engine load in most types of construction and industrial equipment, and in some
cases (e.g. hydrostatically driven crawlers) they are nearly the entire load.
Some cranes and large earthmoving machines use diesel-electric systems like
those in locomotives. In most construction equipment, however, a large part of
the engine power requirement is for moving the machine, through a direct
mechanical linkage with the wheels or tracks.
7-1
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•vHydrostatic and diesel-electric drive systeals allow the engine to
maintain a relatively constant speed, although the engine torque required at
{that speed may fluctuate. Direct mechanical drive, on the other hand, imposes
tfc
.large transient changes in speed and load .on the, engine". The need to generate
full or near-full engine torque at low, engine speeds in many operating cycles
leads to high "transient smoke, and probably high particulate missions as well.
Diesel engines in -construction" machinery must operate in a brutal
physical environment. This is especially true of engines in mechanical-drive
applications, where.shock and vibration loads may be transmitted through the
drivetrain to the engine. Reliability is also very important—failure of a few
large machines could seriously disrupt a construction schedule. This imposes
stringent requirements for robustness and reliability on the engine. To be
commercially feasible, any emission controls would have to be similarly _ robust
and reliable.
7.2 Current Emission Factors
The best data on emission factors for construction and industrial-
equipment are"contained in a report to the California Air. Resources Board byj
Environmental Research and Technology (ERT) (1982)7 This report was„ sponsored
by the farm equipment, construction equipment, and engine industries through
their respective associations, and includes massive amounts of
manufacturer-supplied data. Although the report deals specifically with
California, the emission factor data contained in it are the best available for
remainder of the U.S. as well. ;These data are presented in Table 7-1.
As discussed in Section 6-2, the data in' the ERT report suffer from.?
several limitations. The most important of these is the absence of.particulate
k- measurements. As a result, the FM emission factors in Table • 7-1. were takenj;
from AP-42 (EPA, 1985). EMA's criticism of these emission factors, and our
response, have already been discussed in Section 6-2. As was also the case
with farm equipment, we decided to retain these factors essentially for lack of
7-2
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cei»aaavioii
TABLE 7-1. ESTIMATED CURRENT EMISSION FACTORS FOR DIESEL ENGINES
USED IN CONSTRUCTION AND INDUSTRIAL EQUIPMENT
EMISSION FACTORS (G/BHP-HR)
HC1
CO1
NOx1
PM2
Equipment Type
Track Type Tractor. 90+ HP
0.37
1.65
6.60
0.69
Track Type Tractor 20-89 HP
1.33
2.91
9.63
0.66
Track Type Loader, 90+ HP
0.47
1.56
7.76
0.66
Track Type Loader, 20-89 HP
1.80
3.02
10.97
0.69
Wheel Loader > 2-1/2 cubic yard
0.60
2.07
8.31
0.81
Wheel Loader < 2-1/2 cubic yard
1.29
3.26
, .9.24
0.81
Industrial Wheel Tractor
1.76
7.34
11.91
1.27
Skid-Steer Loader
1.76
7.34
11.91
1.27
Wheel Tractor Scraper
0.55
2.45
7.46
0.79
Off-Highway Truck*
0.37
2.28
8.15
0.50
Motor Grader
0.36
1.54
7.14
0.63
Hydraulic Excavator, All
1.22
3.18
11.01
0.90
Trencher
1.10
4.57
10.02
0.90
Concrete Paver**
1.10
4.57
10.02
0.90
Bituminous Paver
0.99
5.19
11.18
0.90
Roller Compactor, Vibratory
1.06
6.72
14.27
0.78
Roller Compactor, Static
0.88
5.33
11.84
0.78
Crane, Wheel
0.59
4.99
12.45
0.90
Crane, Crawler
0.59
4.99
12.45
0.90
Crane, Hyd., Wheel, 1-Station
0.80
7.80
14.69
0.90
Crane, Hyd., Wheel, Multi-Station
0.68 .
3.71
12.47
0.90
Log Skidder
0.61
3.18
9.82
0.90
Pipe Layer
0.59
4.99
12.45
0.90
Fuel-Weighted Emission Factors
lb/1000 gal
29
117
360
31
g/BHP-hr
0.74
2.94
9.08
0.77
* Also wheel dozer, pavement cold planer.
**Also generators, pumps, compressors
Sources:
1ERT. 1982.
2EPA, AP-42, 1985.
7-3
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RADIAN
coavoaaT • oat
arty more applicable data. As the FM factors used for construction equipment
are—generally. . lower than those used in farm equipment (reflecting the more
modern, larger, and cleaner engines tested), they may be considered less,
-objectionable as a.result. Research to obtain more recent and applicable
emissions data for construction equipment is strongly recommended"; however.
Also shown in Table 7-1 are a set of "fuel-weighted" emission factors
for construction and industrial equipment. These are the ^weighted averages of
.<$ the emission factors for each equipment type, with the weighting proportional
'to the fuel consumed by each type of machine. Fuel consumption estimates for
each machine type are shown in Table 7-2.
A major limitation of both the ERT data and the AP-42 particulate
factors is the fact that both were based on the old 13-mode steady-state test
cycle, and thus do* not account for any transient effects. Since, most
construction-equipment operation involves a highly transient, duty cycle? this
< is a much greater problem for construction and industrial equipment than for
farm equipment. Many construction equipment operating cycles require full or
near-full engine torque at low engine speeds—a situation which can produce
very high particulate emissions. The frequent puffs of black smoke emitted by
many construction machines operated on such cycles are testimony to the
potential for high emissions. As a result, the HC and FM emissions factors?
shown in Table 7-1 may significantly understate the real emissions." Research
to resolve this issue is recommended.
7.3 Engine Population and Emission Factor Data
Population and emission estimates for construction and industrial
equipment are listed in Table 7-2. The utilization and duty-cycle data in
this table were taken from the ERT report to the California Air Resources Board
(1982). At the time our Task 1 interim report was prepared, no national-level
population data were available for construction and industrial equipment. As a
result, national populations were calculated by scaling up the California
7-4
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TABLE 7-2. ESTIMATED POPULATION, FUEL CONSUMPTION AND EMISSIONS FROM
DIESEL ENGINES USED ON CONSTRUCTION AND INDUSTRIAL EQUIPMENT
II
01
Diesel1
Popula t ion
Usage^v/
(hr/yr)
Avg. Load Consumption EMISSIONS (TONS/YEAR)
H.P. Factor (1000 gal) HC CO NOx
ft
PM
I
000/ 1350
000! 865
000 •' 1175
000: 850
> 2-1/2 cubic'yard 30?e 74,00(P 26
7.
128
682
194
220
22,842
2.292
22,214
548
578
1,403
166
2.040
40
TOTAL
DOE/EIA "Off-Highway" Fuel Cons.
1,047,805
V
3,279,661
i
1.616, 685"*
47.820 191.064 590,372 50.021
23.572
94,184
291.0196 24.6S76
Sources:
1 4
^Construction Equipment Magazine. March-July, 1987. ^Calculated by assuming fuel consumption of 0.4 lb/BIIP-hr.
Radian estimates based on California data. 6EIA' *985.
ERT, 1982. "Fuel-weighted" emission factors times DOE/EIA estimate.
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radian
populations estimated as a part of the ERT study. This was accomplished by
dividing the California population by the ratio o-* 1979 California sales to
1979 U.S. sales of construction and industrial equipment.
In comments on our interim report, the Engine Manufacturer's
Association accepted this general approach, but suggested that the estimated
populations be adjusted downward to,reflect declining sales of construction and
industrial equipment since 1979 (Young, 19873." Since that time, however.
Construction Equipment Magazine has published the result of a nationwide survey
of construction equipment users, including population estimates for nearly all
major classes of construction equipment (Landers, 19 87).. These population
estimates, adapted to fit the classifications used in the ERT report, are the
ones shown in Table 7-2. Although the equipment classes in this survey were
not precisely coincident with those in the ERT report, the correspondence was
close enough in every case to allow a reasonable allocation to be made.
Several categories shown in Table 7-2 require some additional
explanation. The Construction Equipment survey estimated the number of, backhoe
loaders, which the ERT . report .jumped ^ with\ other, _ similar** machines T as>
'"industrial wheel tractors". The CorTs'truc t i"o7T Equipment ""es tiaate of J 189,000
backhoe loaders_was arbitrarily increased by 40 percent to ..reflect the; presence
, of other" classes', of ' industrial tractors not included in the- survey." This was
then "reduced by 20 percent to reflect the assumed fraction of gasoline" engines^
in the population
The ERT report included no equipment category for skid.-steer loaders,
although these are extremely common small construction machines. We^assumed
that the emission factors and usage patterns for these machines would be
similar^to^tho"se^_for .industrial wheelv tractors, and. further-assumed; that" 801
percent ; of the. skid-steer loaders' reported were diesellTpowered. These
estimates are reflected in Table 7-2. In addition, the Construction Equipment
survey contained no data for log skidders or pipelayers. Population estimates
for these equipment types were carried over from our Task 1 interim report.
7-6
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RADIAN
Total fuel consumption and pollutant emissions by construction and
industrial equipment were calculated using the same approach as for t.farm
eg.
equipment, and are also reported in Table 7-2, As this table indicates». no^
one.category of construction and industrial equipment is,dominant. The four
largest*.'categories, are track-type tractors, large wheel loaders, hydraulic
excavators, and off-highway trucks, but',!'many other "equipment .categories are
Jlso* major ^contributors.
Table 7-2 also shows the total fuel consumption calculated from the
ERT data and, for comparison, the to't'al^ fuel consumption" for. "off-highway"
equipment estimated by DOE. As the table shows, the"-, DOE estimate is
"only about half' of the value calculated from our estimates. Whether this is
due to an overestimate on our pare (as a result of unrealistically high load
factors, usage estimates, or average horsepower, for instance), or to an
underestimate on DOE's part is unclear. As a matter of interest, the emissions
which, would result from assuming that the DOE value is' correct, and scaling
back the ERT estimates proportionally, are also shown.-
7.4 Emissions Test Cycles
As discussed in Section 7.2 above, the operating cycles of many types
of construction machinery include large transient changes in engine speed and
load. A front-end loader, for instance, cycles between full engine power and
low-load operation at least three times in the course of a loading cycle, which
may take only 15-30 seconds to complete. Hydraulic excavators and other
construction machines exhibit similar large cyclic swings in engine load and
speed. These often result in high visible smoke emissions, and it is likely
that they cause high PM emissions as well.
Due to the large number of machine designs and duty cycles, it would
be impractical to develop an emissions test cycle reflecting each specific
operating pattern. However, by recording speed and load measurements on a
large number of engines in different types of construction machines, it might
be possible to develop a "generic" transient test cycle which would result in
7-7
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RADIAN
8.0 MOBILE REFRIGERATION UNITS
Small, engine-pcwered refrigeration units are used to provide cooling
for refrigerated trailers, shipping containers, truck bodies, and rail cars.
These units are overwhelmingly diesel powered, due to the high efficiency of
the diesel engine and the ready availability of its fuel. Although they are
individually small in pcwer output, the large number of refrigeration units in
use and the large number of operating hours per unit make them a
not-inconsiderable contributor to total diesel emissions.
Mobile refrigeration units have received relatively little study,
compared to the other equipment categories considered in this report, and the
funds available for this preliminary study did not permit an in-depth
investigation. As a result, the estimates presented here are even more
uncertain than those in the previous sections. More extensive investigation,
including actual emissions testing of a sample of refrigeration units, is
strongly recommended.
8.1 Engine Characteristics and Operating Conditions
Diesel engines used for mobile refrigeration are typically small,
naturally-aspirated, high-speed engines classed in Group 4. Power ratings
range from less than 10 H.P. up to around 70 HP for some truck units, while
railcar refrigeration units are reported to have an average of 88 H.P. Both
direct-injected (DI) and indirect-injected (IDI) engines are used, but the
market trend is toward increased use of DI engines. This is due to the greater
fuel efficiency, lower heat losses, and easier cold starting of the DI engines.
Diesel engines in mobile refrigeration units typically run
continuously while the unit is in use, being shut off only when the car or
trailer will not be used for an extended period. In most units, the engine and
compressor are sized to deal with the maximum anticipated cooling load. This
8-1
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ctiMiariti
may include cooling down a just-loaded cargo, as well as keeping it cool under
the most extreme climatic conditions expected. As a result, they are
substantially oversized for normal cooling requirements. Most mobile
refrigeration units handle this by cycling between full-power operation with
the compressor running and letting the engine idle when the compressor is not
needed. Thus, depending on the cooling requirements of the load, the engine
often spends the great bulk its time idling.
To reduce fuel consumption, some newer mobile refrigeration units are
incorporating a more complex control strategy—for instance, using full-speed
operation for rapid cooldown when required, and a slower, more fuel-efficient
speed for keep-cool operation. Systems allowing automatic shutdown and restart
of the engine when it is needed are also available. We were unable to
determine the degree of market penetration of these systems, but it is believed
to be relatively small.
8.2 Current Emission Factors
Emissions data for engines used in mobile refrigeration are
unavailable. Table 8-1 shows some rough estimates of these factors, based on
data for similar engines in other applications. For railcar refrigeration
units, the most common engine is the DDA 2-71. The emission factors shown are
based on a 6V-71 engine (Hare et al., 1975), This engine has more cylinders,
but is otherwise similar to the 2-71 in combustion technology. The NC>x
emissions for this engine reported by Hare, et al. have been adjusted downward
somewhat, and the PM emissions adjusted upward to reflect the effects of
wear in the injector linkage and changes in engine technology since 1975.
Euen less information is available on emissions from engines in truck
and container refrigeration units. The emission factors shown in Table 8-1 for
these units are Radian estimates, based on typical emissions performance for
small DI and IDI diesel engines, and may well be grossly wrong. It is likely
that these emissions values vary greatly from manufacturer to manufacturer, so
even a few emissions data points would not help greatly to improve the
estimates,
8-2
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eoooiiTi
TABLE 8-1. ESTIMATED CURRENT EMISSION FACTORS FOR DIESEL
ENGINES USED TOR MOBILE REFRIGERATION
EMISSION FACTORS
g/BHP-hr lb/1000 gal,
Railroad Car Units
HC
CO
NOx
FM
1.0
4.0
16.0
0.4
40
159
634
16
Truck/Container Units'
HC
CO
NOx
PM
1.2
5.0
8.0
0.6
48
198
317
24
Sources:
1
Radian estimates based on DDA 2-71 engine.
Radian estimates based on typical small DI and IDI engines,
8-3
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€•»»•»• fltl
8.3 Engine Population and Emissions Inventory
-1-1 .i i in ——i———
Estimated nationwide population, fuel consumption, and emissions for
diesel engines used in mobile refrigeration units are shown in Table 8-2.
Estimates of the national population of truck and container refrigeration units
were obtained by summing annual sales data (obtained from Refrigerated
Transporter magazine) over an estimated 15 year useful life. The number of
refrigerated train units was taken from statistics of the Association of
American Railroads (1986). The average horsepower, load factors, and
hours-of-operation shown for these units are Radian estimates, based on limited
data and conversations with persons involved in the industry.
Like the industries which use them, mobile refrigeration units should
tend to be concentrated in urban areas and their immediate surroundings, as
these are the major termini for refrigerated railcars and truck trailers. The
degree of urban operation for these units is probably similar to that of the
vehicles which transport them: trains and on-highway trucks.
8.4 Emissions Test Cycle
Emissions from a mobile refrigeration unit are affected by the
overall design of the unit, including the compressor, heat-exchangers, and
control system as well as the engine. An appropriate test procedure should
therefore measure emissions against the useful output of the system: i.e. BTU
of cooling supplied under specified conditions (which should include cyclic
operation). This would result in emissions credit for shutdown/restart rather
than continuous idle, use of more efficient compressors, and other design
features which would reduce missions in the real world. Unfortunately,
sufficient data to specify such a test cycle were unavailable for this
preliminary study. Thus, the discussion of achievable emissions standards m
Section 8.5 is limited to g/BHP-hr numbers only.
8-4
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TABLE 8-2. ESTIMATED NATIONWIDE POPULATION. FUEL CONSUMPTION. AND
EMISSIONS FROM DIESEL ENGINES USED FOR MOBILE REFRIGERATION
3 3 3 Fuel 4
Est. Avg. Usage Load Cons. Total Emissions (Tons/Yr)
Application Fop. HP (hr/yr) Factor (1000 Gal) HC CO NOx PM
Tram 30.0001 88 8000 0.2 234,66? 4,693 18,656 74,389 1,877
Truck/Container 173.OOP2 27 5000 0.2 259.500 6,228 25,691 41,131 3,114
TOTAL 203.000 494.167 10,921 44,347 115,520 4.991
Sources:
1
Association of American Railroads, 1986.
2
Calculated from annual sales data, assuming 15-year life.
3
Radian estimate.
4
Calculated assuming fuel consumption of 0.4 lb/BHP-hr.
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!?»«*!?
8.5 Feasibility of Emissions Control
Emission control techniques applicable to mobile refrigeration
engines in the intermediate term include indirect injection or optimized
direct-injection combustion systems, retarded injection timing, combustion
chamber optimization, and exhaust gas recirculation. The emissions standards
estimated to be achievable through these techniques are shown in Table 8-3.
These standards are based on the 1988 on-highway truck standards (adjusted to
reflect steady-state operation), and are probably somewhat conservative. Many
existing IDI engines can undershoot these standards by a considerable margin.
Wade and co-workers (1985) have also demonstrated the capability to control
small DI engine emissions to levels well below the values shown. As before,
however, the reader is cautioned that these estimates are preliminary only, and
that additional research to confirm these estimates would be needed before
these or any other emission standards were incorporated into law.
The major advanced emission control technologies applicable to mobile
refrigeration engines would be catalytic trap-oxidizers, in combination with
EGR and an electronic engine control system. The figures for "advanced
technology" in Table 8-3 reflect these technologies. The major problem facing
trap-oxidizer development in motor vehicles is the unpredictability of the
operating conditions, which complicates regeneration system design. Since
the engine in a mobile refrigeration unit is under complete independent
control, the regeneration system could be simple. Successful trap-oxidizer
operation in a similar application (a diesel-powered heat-pump) was
demonstrated some years ago by Volkswagen.
8.6 Cost-Effectiveness Analysis
Table 8-4 shows some very rough estimates of the cost-effectiveness
of the "intermediate" emissions control levels in mobile refrigeration units
for railcar and truck/container service. The control costs shown assume the
application of engine modifications, retarded timing, and either EGR or
8-6
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esi»«ia«i»i
TABLE 8-3. ESTIMATED ACHIEVABLE EMISSIONS CONTROL STANDARDS
FOR DIESEL ENGINES USED IN MOBILE REFRIGERATION
Equivalent
Emissions
Emission
Limit
Factor
(g/BHP-hr)
(lb/1000 gal.)
Intermediate Control Level
NQx
6.00
238
HC
1.00
40
PM
0.50
20
Advanced Technology
NOx
5.00
198
HC
0.30
12
PM
0.10
4
Source: Radian estimates.
8-7
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eeap»pnv oe~
TABLE 8-4. ESTIMATED COST-EFFECTIVENESS OF EMISSIONS CONTROL
FOR DIESEL ENGINES USED IN MOBILE REFRIGERATION
Train car
Truck and
Container
COST OF EMISSION OONTROLS
Engine Horsepower
88
27
Initial Cost of Controls
$600
$400
Engine Life (yrs)
15
15
Amortized Cost/year § 10%
$ 79
$ 53
Fuel Cons, Increase
3%
2%
Annual Fuel Cons. (Gal)
Baseline
7.800
1.500
With controls
8,034
1,530
Added Fuel Cost @ S0.80/gal
$187
$ 24
Addl. Ann. Maintenance
$ 80
$ 40
Annualized Control Cost Per Unit
$346
$117
EMISSIONS
Emission Factors (lb/1000 gal.)
Baseline
NOx
634
317
HC
40
48
PM
16
24
With Controls
NOx
238
238
HC
40
40
PM
20
20
Annual Emissions (lbs per unit per year)
Baseline
NOx
4,945
476
HC
312
72
PM
125
36
With Controls
NOx
1,912
364
HC
321
61
PM
161
31
Emissions Reduction (lbs per unit per year)
NOx
3,033
111
HC
(9)
11
PM
(36)
5
Cost-Effectiveness ($/ton)
NOx + HC
$229
$1,909
8-8
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cei»oaiti»a
turbocharging and aftercoolmg for emission control purposes. These cost
estimates are highly uncertain—much more investigation of the technology and
operating constraints would be required to develop reliable cost estimates for
these engines.
A similar level of uncertainty surrounds the emission reduction
estimates. Due to the absence of data on current emissions, the emission
reductions available are uncertain, as is the cost-effectiveness of control.
As Table 8-4 indicates, however, missions control for these engines could
potentially be highly cost-effective, with a cost per ton of HC and NO^ removed
ranging from $229 to $1,909. This broad range suggests the level of
uncertainty m the data. Further research to arrive at a more precise
quantification of this potential is recommended.
8-9
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BftfiMW!
9.0 SUMMARY, CONCLUSIONS AND RECOMMENDATIONS
This section pulls together and summarizes the results detailed in
the preceding five sections, and presents our conclusions and recommendations.
9.1 Summary and Conclusions
As the preceding five sections have shown, total pollutant emissions
from off-highway diesel engines are large both in absolute terms and in
proportion to their total numbers, pcwer output, and fuel consumption. Table
9-1 summarizes the estimated population, annual fuel consumption, and emissions
for the five classes of off-highway diesel engines considered in this report.
Off-highway diesel engines are estimated to produce about 2.75 million tons of
NO^ per year, 187,000 tons of particulate matter, 232,000 tons of unburned HC,
and 959,000 tons of CO. These values are about 12.6 percent, 2.4 percent, one
percent, and 1*.25 percent, respectively, of estimated total emissions of these
pollutants from all sources nationwide (EPA, 1986).
More significant than the off-highway diesel contribution to the
total emissions inventory is the off-highway contribution to the total for all
mobile diesel engines, , both on and\ off-highway. Table 9-2 shows this
calculation. As this table indicates, off-highway diesel engines are
responsible for a disproportionate fraction of the total: accounting for 56
percent of the NO^ emissions, 57 percent of. CO emissions, and 48 percent of HC
emissions from mobile diesel engines, but^only, 41 percent of the' diesel fuel
""burned. Their contribution to 'PM^ emissions is less than proportionate,
however, at 36l5"percent"oC the total. Due to limited data, the numbers in
Table 9-2 are somewhat"* crude , butt the conclusion, is< inescapable: off-highway
diesel engines are currently an important source of emissions,** comparable in
magnitude to on-highway diesels.
Diesel engines in on-highway vehicles have been subject to emission
regulations for many years, and have recently received a great deal of
9-1
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TABLE 9-1. ESTIMATED NATIONWIDE POPULATION AND EMISSIONS FROM DIESEL ENGINES
USED IN OFF-HIGHWAY APPLICATIONS
Total Fuel
No. of Horsepower Consumption Emissions (tons/yr)
Engines (1,000s) (1,000 gal) HC CO NO^ PM
Locomotives
1
26,105
Medium Speed
Percent of Nationwide
Marine Vessels
High Speed
Medium Speed
Total
Percent of Nationwide
Farm Equipment
High Speed 3,868,019
Percent of Nationwide
438.000
5,000
443.000
61,111
45,471
11.173
56.644
332,139
3.409,476 30,999 308.558 901,645 37.041
0.13% 0.40% 4.161 0.48%
915,671 14,651 54,482 199.616 10,9188
917,607 18,811 85,796 244,542 9#J76
1,833.278 33,462 140.278 444,158 20,164
0.14% 0.18% 2.05% 0.26%
3,021,561 108,603 274.669 688,874 75,103
0.46% 0.36% . 3.17% 0.97%
Construction and Industrial Equipment
High Speed 1,047.805 124.056
Percent of Nationwide
Mobile Refrigeration
High Speed 203.000 9.518
Percent of Nationwide
3.279.661 47,820 191.064 590,372 50,021
0.20% 0.25% 2.72% 0.65%
494.167 10,921 44,347 115,520 4,991
0.0 5% 0.06% 0.53% 0.06%
TOTALS
High Speed 5,556,824
Medium Speed 31,105
Total . 5.587,929
Percent of Nationwide
511,184 7,711.060 181,995 564,562 1,594,382 141,103
72,284 4,327.083 49.810 394.354 1.146.187 46.217
583.468 12.038.143 231.805 958.916 2.740.569 187,320
0.98% 1.25% 12.63% 2.43%
Percent of nationwide emissions inventory for that pollutant based on EPA (1986)
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(OIPOtAf ION
TABLE 9-2. COMPARISON OF NATIONWIDE FUEL CONSUMPTION AND EMISSIONS
OFF-HIGHWAY VS. ON-HICHWAY DIESELS
Fuel
Consumption
Emissions
(tons/yr)
(1,000 gal}
HC
CO
NO
X
PM
Off-Hiahway Diesels
(mid-1980s)*
Locomotives
3,409,476
30,999
308,558
901,645
37,041
Marine Vessels
1,833,278
33,462
140,278
444,158
20,164
Farm Equipment
3,021,561
108,603
274 , 669 -
688,874
75,103
Const./Ind. Equipt.
3,279,661
47,820
191,064
590,372
50,021
Mobile Refrigeration 494,167
10,921
44,347
115,520
4,991
Total Off-Highway
12,038,143
231,805
958,916
2,740,569
187.320
On-Hij>hway-Diesels
(calendar 1984)^
Heavy-Duty Vehicles
m
242,290
693,832
2,136,563
297,357
Light-Duty Vehicles
m
8,820
28,634
44,052
28,634
Total On-Highway
17.279,650
251,110
722,466
2,180,615
325,991
Total: All Mobile
Diesel Engines
29.317.793
482,915
1,681,382
4.921,184
513,311
Off-Highway as
Percent of Alt
4Ta%
*"48". OX
57.0%
36.55
Mobile Diesels
* Source: Radian estimates,
^Source: EPA (1986).
9-3
-------
regulatory attention, which will lead to still lower emissions in the future.
Off-highway engines, since chey do not fall under EPA's statutory authority,
have not been regulated. For "this reason, pollutant emissions per unit of
work produced or fuel consumed by an average off-highway diesel are much
higher than those for an on-highway engine, and the potential for future
reductions in emissions is correspondingly greater.
As discussed in Sections Three through Eight, emission control
technology for on-highway diesel engines is well developed, and this technology
could be transferred to most off-highway engines as well. Off-highway diesel
engines can be divided into high-speed and medium-speed classes, having rated
operating speeds above or below 1300 RPM, respectively^ Except for railway
locomotives, the great majority of off-highway diesel engines are high-speed
types. These share many design features with on-highway truck and light-duty
vehicle engines, so that most emissions control technologies demonstrated in
on-highway engines would be readily transferable. Medium-speed engines are
used in railway locomotives and some marine vessels. Emissions control
technology for these engines is less developed, but even the little work that
has been done shows the potential for major reductions in emissions.
Sections Four through Eight include a case-by-case discussion of
applicable emission control technologies and achievable emissions standards for
diesel engines used in each class of off-highway equipment. Table 9-3
summarizes the emissions standards estimated to be achievable by each class,
as well as the percentage reduction from present levels represented by these
standards. In the intermediate tern, engines in all classes except farm
equipment and construction equipment were estimated to be capable of meeting
emissions standards comparable to the California 1988 NO^ and FM standards for
off-highway vehicles. Construction and farm equipment were estimated to
require a higher NO^ limit, due to the limited potential for turbocharging and
aftercooling.
Given time to develop advanced emission control technology, it was
estimated that engines in railway locomotives and marine vessels would be able
to comply with emissions standards comparable to the Federal 1991 standards for
9-4
-------
TABLE 8-3. MISSIONS STANDARDS ESTIMATED TO BE ACHIEVABLE
BY EACH aASS OF OFF-HIGHWAY DIESELS
Intermediate
Standard
(g/BHP-hr)
Percent
Reduction
Advanced Technology
Standard
(g/BHP-hr)
Percent
Reduction
Locomotives
HO
HC*
PM
Marine Vessels
Medium-Speed Engines
NO
HC*
PM
High-Speed Engines
NO
HCx
PM
Farm Equipment
NO
HC*
PM
6.0
0.50
0.50
6.0
0.50
0.50
6.0
0.50
0.50
8.0
0.50
0.50
551
52%
1%
551
52%
1%
45%
38%
17%
30%
72%
60%
5.0
0.30
0.20
5.0
0.30
0.20
5.0
0.50
0.25
6.0
0.20
0.15
63%
71%
60%
63%
71%
60%
55%
38%
59%
48%
89%
88%
Construction Equipment
NO
HCX
PM
Mobile Refrigeration
NO
HCf
PM
8.0
0.50
0.50
6.0
1.0
0.50
12%
32%
36%
49%
10%
2%
6.0
0.20
0.15
5.0
0.20
0.10
34%
73%
81%
58%
73%
80%
Source: Radian estimates.
-------
RADIAN
(•ItSIIIKI
on-highway vehicles, while chose in mobile refrigeration units should be able
to comply with standards comparable to the 1994 on-highway limits.
Construction and farm equipment could mee£ PM standards similar to the 1994
levels, but—due to their higher load factors—might not be able to achieve
the level of 0.10 g/BHP-hr mandated for on-highway engines. As is also true
of on-highway engines, a reduction in diesel fuel sulfur content might be
required to achieve these low particulate levels. In addition, construction
and farm equipment would also require a slightly higher NO^ limit than that
mandated for on-highway engines, due to the limited potential for
low-temperature charge cooling.
The reader is warned that the emissions limits shown in Table 9-3 are
engineering estimates only, based on very limited data, and intended only to
indicate the potential benefits of regulation in this area. As discussed
below, additional research to confirm these estimates would be essential before
these or any other emission standards were incorporated into law.
Figures 9-1 through 9-3 show the potential effects of introducing the
emissions standards listed in Table 9-3 on NO , HC, and PM emissions from each
x
class of off-highway engines. The leftmost bar for each class represents the
current situation, with no emissions control. The middle bar represents the
emissions that would be experienced if all existing engines met the
"intermediate" emissions standards, and the rightmost bar the emissions that
would result if all existing engines met the "advanced technology" standards.
The net reduction if every off-highway engine in use met the "advanced
technology" standards would be about 1.4 million tons of NO^, 162,000 tons of
HC, and 146,000 tons of PM per year, or 5 2 percent, 70 percent, and 78 percent,
respectively, of the current emissions of these pollutants. In reality, of
course this would take a very long time to achieve, due to the need to turn
over the existing engine population.
The cost-effectiveness of controlling off-highway diesel emissions to
at least the intermediate-term standards shown is estimated to be very
favorable compared to the costs of other available emission control measures of
9-6
-------
RAM AM
ttantiAvita
u
w
c
0
*0)
X C ••
i 5
4) -*
"3 •*
^ Z
* W
c
o
2
0.9
0.8
0.5
0.4
0.3
0.2
0.1
0.7 i
0.6
I
I
^1
III
L
II
as
R!
6\i
,
rXi
vXi
III
Marine Farm Construction Mobile
Locomotives Vessels Equipment Equipment Refrigeration
IZ2
Uncontrolled
KS
Int. Controls
777?.1
Adv. Controls
Figure 9-1. Estimated Effect of Emissions Controls
on Total Off-Highway NO Emissions
9-7
-------
RAMAN
Marine Farm Construction Mobile
Locomotives Vessels Equipment Equipment Refrigeration
IZ2 ESI ^
Uncontrolled Int. Controls Adv. Controls
Figure 9-2. Estimated Effect of Emissions Controls
on Total Off-Highway EC Emissions
9-8
-------
1
I
i a.
I
i
1
1
!
i
Marine Farm Construction _ Mobile
Locomotives Vessels Equipment Equipment Refrigeration
1771 ESI VM
Uncontrolled Inc. Controls Adv. Controls
Figure 9-3. Estimated Effect of Emissions Controls
on Total Off-Highway PM Emissions
-------
RADIAN
coiroiifioa
similar significance. Estimated cost-effectiveness values for a number of
specific equipment types are shown in Table 9-4. While based on crude
preliminary cost estimates, these values are believed to somewhat conservative
(fn the sense of over-stating emissions control costs, and thus the costs per
ton of pollutants eliminated). Despite this, the cost estimates for control of
NO and HC range from a few hundred to about three thousand dollars per ton.
For comparison, the fuel cost alone for reducing the 1991 NO^
standard for heavy-duty on-highway engines from 5.0 to 4.0 g/BHF-hr (a step
which is often suggested) is estimated at about $2,000 per ton (assuming a 4
percent fuel economy penalty and fuel at $0,80 per gallon excluding taxes).
The incremental cost-effectiveness of the 1994 PM standard of 0.1 g/BHP-hr for
heavy-duty on-highway engines has been estimated at about seven to eleven
thousand dollars per ton (Weaver and Klausmeier, 1987a).
9.2 Recommendations
• Much research remains to be done to develop a more complete
understanding of off-highway vehicle emissions, control technology,
and cost. The following are sane key areas for further research.
1. Improved duty cycle characterization for all off-highway engine
classes, leading to improved emissions measurements and to the
development of representative test procedures.
2. Development of suitable emissions measurement techniques for
off-highway vehicles (such as marine vessels and construction
equipment) for which dynamometric techniques are impractical.
This will probably require portable sampling equipment to
measure diesel emissions during normal operation of the vehicle.
3. Extensive emissions measurements on current production engines,
and on in-use equipment, leading to more accurate emission
factors.
9-10
-------
TAILS 9-4. ESTIMATED COST-EFFECTIVENESS OF "INTERMEDIATE LEVEL"
EMISSIONS CONTROLS FOR DIFIERENT CLASSES OF OFF-HIGHWAY
VEHICLES
Cost Effectiveness (S/ton)1-
NO + HC PM
x
Locomotives
New
$1,073
2
~~ J
Retrofit
1,332
z
Marine Vessels
Medium Speed
672
2
2
High-Speed Propulsion
838
2
High-Speed Generator
616
Farm Equipment
Large 4MD Tractor
845
3,067
Small Tractor
2,960
7,607
Combine
848
1,900
Construction Equipment
Hydraulic Excavator
748
8,969
Industrial Tractor
1,567
5,323
Concrete Paver
2,045
3,961
Mobile Refriaerator
Railcar Unit
229
2
Truck/Container Unit
1,909
-------
IWJRWW!
4. Development of improved estimates of engine populations, age and
technology, utilization, and fuel consumption in order to
.provide accurate emissions inventories.
5. Assessment of urban-area and regional-scale effects of
off-highway vehicle emissions.
6. Study of effects of available emission control technologies in
individual engines and vehicles. It is recommended that EPA
perform only preliminary studies in tis area, as experience has
shown that detailed development and optimization of emissions
controls is best left to the manufacturers.
7. Much more detailed analysis of the costs of control, including
costs of accommodating any changes in engine performance and/or
transient response.
8. Evaluation of in-use deterioration in emissions in off-highway
equipment, including the effects of tampering and malmaintenance
of emissions controls. A recent study for the California ARB
(Weaver and Klausmeier, 1987b) concluded that these effects
could result in heavy-duty truck PM emissions more than double
the applicable standards, and similar increases might be
expected in off-highway engines.
In the event that emissions regulations are considered for farm and
construction equipment engines, careful consideration should be given
to phase-in mechanisms in order to avoid undue burden on the
industry. An averaging, trading, and banking approach with
"crawling" target levels, such as that discussed in Section
6.5, would be one fairly straightforward way to do this.
9-12
-------
RJWian
In the event that emissions regulations are considered for new
mediua-speed marine and locomotive engines, consideration should also
be given to establishing retrofit requirements for older engines in
these categories. These requirements could most conveniently apply
at the time of rebuild. .
9-13
-------
.0 REFERENCES
Association of American Railroads (1986), Railroad Facts. Washington, D.C.
Baker, Q.A. (1981) "Use of Alcohol-in-Diesel Fuel Emulsions and Solutions
in a Medium-Speed Diesel Engine", SAE Paper No. 810254, Society of
Automotive Engineers, Warrendale, PA.
Baker, Q.A. (1980) "Alternate Fuels for Medium-Speed Diesel Engines", SAE
Paper No, 800330, Society of Automotive Engineers, Warrendale, PA,
Baker, Q.A., S. Ariga, K.H. Rosegay, N.R, Sefer, B.K. Baily, J.Erwin, and
J.F. Wakenell (1984) Alternative Fuels for Medium-Speed Diesel Engines
(AFFMSDE) Program: Fourth Research Phase Final Report, Report No. R-569,
Association of American Railroads, Washington, D.C.
Brev, F., R. Topp, and B.E. Enga (1987) "Application Engineering of
Particulate Control Systems for Underground Use", SAE Paper No. 870255,
Society of Automotive Engineers, Warrendale, PA.
Cartellieri, W.P. and W.F. Wachter (1987) "Status Report on a Preliminary
Survey of Strategies to Meet U.S. 1991 HD Diesel Emission Standards
Without Exhaust Gas Aftertreatment", SAS Paper No. 870342, Society of
Automotive Engineers, Warrendale, PA.
Crowe11, G. (1986), personal communication, Chief of the National Harbors
and Waterways Office, Army Corps of Engineers, New Orleans, LA.
Davis, W. (1986) pe rsonal communication, Electromotive Division, General
Motors.
Dowdall. D.C. (1987), letter dated January 29, 1987 to C.S. Weaver of
Radian, Caterpillar Inc., Peoria, IL.
Electromotive Division, General Motors (1978) "Status Report on Exhaust
Emissions From New EMD Locomotives", LaGrange, IL.
Engineering Science, Inc. (1984) Emission Factor Documentation for AP-42:
Section 3.2.3, Inboard Powered Vessels, Report under EPA Contract No.
68-02-3509, EPA-450/4-84-001, U.S. Environmental Protection Agency,
Research Triangle Park, NC.
Environmental Research and Technology, Inc. (1982), Feasibility, Cost, and
Air Quality Impact of Potential Emission Control Requirements on Farm,
Construction, and Industrial Equipment in California. Los Angeles, CA.
Euing, M. (1986), personal communication. Refrigerated Transporter
magazine, Houston, TX.
10-1
-------
RfliPBHM
viom
Hardenberg, H.O, (1987) "Urban Bus Application of a Ceramic Fiber Coil
Particulate Trap", SAE Paper No. 870111 in Diestl Particulates: An Update,
SP-702, Society of Automotive Engineers, Warrendale, PA.
Hare, C.T., K.J. Springer, and T.A. Huls (1975) "Exhaust Emissions from
Farm, Construction, and Industrial Engines and Their Impact", SAE Paper
Ho. 750788, Society of Automotive Engineers, Warrendale, PA.
Harvest Publishing Co. (1985) Harvest 1985 Tractor Survey. Cleveland, OH.
Implement and Tractor Magazine (1986), Red Book Issue, Vol 101, No.4.
Ingalls, M. (1985), Recommended Revisions to Gaseous Emission Factors From
Several Classes of Off-Highway Mobile Sources, report by Southwest
Research Institute under EPA Contract 68-03-3162, Work Assignment 8, U.S.
EPA, Ann Arbor, MI.
Kotlin, J.J. and H.A. Williams (1975) "Low Smoke Diesel Engines; A
Progress Report on Electromotive's Emission Reduction Program",
Electromotive Division, General Motors, LaGrange, IL.
Landers, K. (ed.) (1987) "Machines at Work in America", series of articles
m Construction Equipment, February 15 through July 15, 1987.
Lilly, L.R.C. (ed.) (1984) Diesel Engine Reference Book. Butterworth's
Ltd., London, U.K.
Moyat, R. (1986), personal communication, National Marine Manufacturers
Association, Chicago, IL.
Mcdonald, C.W. (1982), Diesel Locomotive Rosters; United States, Canada,
and Mexico. Kalmbach Publishing Co., Milwaukee, WI.
Millar, M. , J. Bunch, A. Vyas, M. Kaplan, R. Knorr, V. Mendiratta, and C.
Saricks (1982) Baseline Projections of Transportation Energy Consumption
by Mode; 1981 Update. ANL/CNSV-28, Argonne Natl. Laboratory, Argonne. IL.
O'Donnel, J. (1986), personal communication. Southwest Marine, Alameda, CA
Olson, L.E. and W.M. Reed (1987) "Overview of Compressed Natural Gas for
Rail Locomotive Application", presentation to the South Coast Air Quality
Management District, Clean Fuels Demonstration Workshop, El Monte, CA, November
16, 1987.
Owen, D.(ed) (1986) Inland River Record, Waterways Journal, St. Louis, MO.
Santa Barbara County Air Pollution Control District (1987) Crew and Supply
Boat N0^ Control Development Program. Santa Barbara, CA.
10-2
-------
Scarborough (1986), personal communication, U.S. Coast Guard Headquarters
Washington, D.C.
6&
Storment, J.O., K.J. Springer, and K.M. Hergenrother (1974) "NOx Studies
with EMD 2-567 Diesel Engine", ASME Paper No. 74-DGP-14, Society of
Automotive Engineers, Warrendale, PA.
U.S. Army Corps of Engineers (1983), Summary of U.S. Flag Passenger and
Cargo Vessels, New Orleans, LA.
U.S. Bureau of the Census (19855, Statistical Abstract of the U.S..
U.S. Government Printing Office, Washington, D.C.
U.S. Dept. of Agriculture, Agriculture Statistics 1984. U.S. Government
Printing Office, Washington, D.C.
\
U.S. Dept. of Transportation (1985) National Transportation Statistics:
Annual Report, DOT-TSC-RSPA-85-5. U.S. Govt. Printing Office, Washington,
D.C,
U.S. Energy Information Administration, Petroleum Marketing Monthly,
"Annual Report on Sales of Fuel Oil and Kerosene, 1985", U.S. Dept. of
Energy, Washington, D.C.
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Emission Estimates. EPA-450/4-85-014, Research Triangle Park, NC.
U.S. Environmental Protection Agency (1985) Compilation of Air Pollutant
Emission Emission Factors. AP-42, Vol 2. Washington, D.C.
U.S. Maritime Administration, "Annual Report - 1983", Washington, D.C.
U.S. National Marine Fisheries Service (1984), Fisheries of the United
States, U.S. Government Printing Office, Washington, D.C.
Wade, W.R., C.E. Hunter, F.H. Tr inker, and H.A. Cikanek (1987) "The
Reduction of NO^ an(j Particulate Emissions in the Diesel Combustion
Process", ASME Paper No. 87-ICE-37, American Society of Mechanical
Engineers, New York, NY.
Wade, W.R., T. Idzikowski, C.A. Kukkonen, and L.A. Reams (1985) "Direct
Injection Diesel Capabilities for Passenger Cars", SAE Paper No. 85055 2,
Society of Automotive Engineers, Warrendale, PA. -
Wakenell. J.F. (1987) presentation at the Society of Automotive Engineers
1987 International Fuels and Lubricants Meeting, Toronto, Ontario, Canada,
November 2, 1987.
10-3
-------
Weaver, C.S. and B.S. Pugh (1986) Feasibility and Cost-Effectiveness of
Emissions Control From Off-Highway Diesel Vehicles: Task One Interim
Report, Report under EPA Contract No. 68-01-7288, Radian Corporation,
Sacramento, CA.
Weaver,C.S. and R.F. Klausoeier (1987a) A Study of Excess Motor Vehicle
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Technologies, Report to the California Air Resources Board under Contract
No. A5-188-32, Radian Corporation, Sacramento, CA.
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Inspection and Maintenance Study: Final Report (4 volumes), Report to the
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(1982) "Single-Cylinder Tests of Emission Control Methods for Medium-Speed
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Radian, Engine Manufacturer's Association, Chicago, IL.
10-4
-------
APPENDIX A
-------
TABLE A-l. SUMMARY OF EMISSION RATES FOR LOCOMOTIVE ENGINES IN SWRI TESTS
PARTICULATE NO* HC CO
Engine Hours Notch g/bhp-hr lb/1,000 gal g/bph-hr g/lb fuel b/bph-hr g/lb fuel g/bph-hr _______
0
1
1,83
86.98
19.47
37,40
2.79
5.35
5.26
10.10
0
2
1.11
41.67
18.83
44.13
1.89
4.41
2.26
5.30
0
2
1.12
41.86
19.42
45.52
1.99
4.66
2.29
5.36
0
3
0.B8
34.93
16.57
41.01
1.81
4.49
2.08
5.15
0
3
0.79
31.16
16.28
40.29
1.85
4.59
2.13
5.28
0
4
0.51
20.84
14.94
37.90
1.80
4.56
3.09
7.84
0
4
0.55
22.21
14.80
37.56.
1.87
4.74 ,
3.12
7.90
0
5
0.55
23.27
13.72
36,39
1.73
4.59
4.25
11.26
0
5
0.48
20.52
13.47
35.72
1.73
4.59
4.36
11.57
0
6
0.51
22.16
11.69
32.92
1.50
4.10
6.07
16.57
0
6
0.58
22.54
11.83
32.32
1.S1
4.13
6.07
16.57
0
7
10.53
29.29
1,33
3.70
3.87
10.76
0
7
0.46
20.34
10.54
29.30
1.33
3.70
3.78
10.51
0
B
0.41
18.27
8.61
24.18
1.33
3.73
2.94
8.24
0
8
0.42
19.06
8.38
23.52
1.31
3.68
2.94
8.26
0
Idle
79.74
23.04
20.20
37.81
250
5
0.44
18.54
12.15
32.22
1.37
3.64
4.32
11.45
250
8
0.43
19.30
8.69
24.40
1.14
3.21
2.91
8.16
250
Idle
77.91
26.73
16.83
32.58
500
3
0.43
16.88
16.64
41.18
1.35
3.34
2.49
6.16
500
4
0.31
12.52
13.77
34.95
1.61
4.38
3.62
9.19
500
5
0.30
12.62
12.18
32.31
1.62
4,29
4.93
13.09
500
6
0.34
14.79
10.35
28,28
1.32
3.61
6.34
1 17.32
500
7
0.32
14.42
9.46
26.31
1.35
3.75
4.52
12.58
500
8
0.33
14.62
8.44
23.71
1.28
3.60
3.24
^ 9.09
500
1
0.28
8.11
22.11
39.58
1.31
2.34
3.12
5.36
500
1
21.45
38.40
1.45
2.60
2.87
5.13
500
2
0.28
11.19
IS. 90
39.93
0.47
1.19
1.46
3.67
500
2
15.41
38.70
0.52
1.32
1.37
3.44
500
3
0.24
10.13
14.42
37.34
0.42
1.07
1.08
2.80
500
3
14.41
37.33
0.46
1.19
1.04
2.68
500
4
0.30
12.41
IS.08
39.34
0.37
0.97
1.74
4.55
500
4
15.26
39.83
0.41
1.0?
1.67
4.36
500
5
0.37
15.58
14.56
38.32
0.32
0.86
1.69
4,44
500
5
14.38
37.86
0.34
0.90
1.75
4.60
500
6
0.38
16.04
12.85
34.04
0.32
0.85
2.95
7.80
500
6
12.98
34.38
0.32
0.84
3.20
8.48
500
7
0.43
18.69
13.00
35.07
0.34
0.91
3.21
8.67
500
7
13.16
35.50
0.37
0.99
3.23
8,72
500
8
0.26
11.46
12.36
33.73
0.41
1.12
2.22
6.07
SOO
a
13.33
33,65
0.37
1.00
2.05
5.58
500
Idle
13.05
34.57
5.59
15.24
500
Idle
34.44
5.78
15.88
Source: Southwest Research (1987} special analysis.
-------
TABLE A-2. QACLOULATION OF CTCLE-AVERAOE EMISSIONS FOB THE SMRI LOCOHOTIVE ENGINE TESTS
FUEL USED NO* EMISSIONS MC EMISSIONS CO EMISSIONS PM EMISSIONS
fW Mi e»S3iona na/iooo bah n pun cfflK |W pop£/>ffl tfliHI ih wpe/HF IlbI ih kpoe/hr ilbi ih mooe/hh ilbi IN mooe/mb ilbi
OPER.
ENGINE HOURS NOTCH (Ib/hrl (B.l, hr NO. HC CO W LINE MITCH AVG. LINE MITCH AVB. LIME WITCH AVO. LINE MITCH AVO. LINE MITCH Ave. LINE 8HI1CH Ave.
0
1
81.7
7.3
880.1
83.0
188.7
87.0
4.B
8.8
7.78
0.38
0.70
0,87
0.20
0.41
0.33
0.03
0.08
o.os
0.08
0.11
O.OB
0.03
0.08
O.OS
0
e
104.8
14.9
896.9
70.9
BE.7
41.B
B.4
4,8
3.89
0,38
0.71
0.08
0.28
o.so
0.40
0.03
0.08
0.04
0.03
0.08
0.08
o.oe
0.03
0.02
500
s
208.2
es.i
838.7
81.8
89.8
18.B
1.B
3.8
3.10
0.68
1.12
0.80
0.38
0.71
0.58
0.03
0.08
0.08
O.OS
0.11
0.09
0.01
0.02
0.02
800
4
380.4
48.8
842.1
83.3
148.8
ie.8
4.8
1.8
3.01
2.18
0.87
1.37
1.18
0.47
0.74
0.14
0.08
0.08
0.31
0.12
0.20
O.OS
0.01
'o.oe
BOO
B
4S4.B
84.•
801.1
88.8
203.0
12.8
1.B
1.0
1.32
1.24
0.82
0.88
0.82
0.31
0.43
0.08
0.04
0.08
0.2S
0.13
0.17
0.02
0.01
0.01
BOO
a
680.2
83.8
438.a
88.0
ees.a
14.8
1.8
1.0
1.32
1.81
0.80
1.11
0.70
0.38
0.4S
0.08
0.04
0,08
0.43
0.22
0.30
0.02
t.,01
0.02
BOO
7
887.2
89.0
408.1
68.2
188.1
14.4
8.4
0.0
0.82
2.38
0.00
0.81
0.88
0.00
0.37
0.14
0.00
0.08
0.47
0.00
0.18
0.03
0.00
0.01
SOO
B
882.1
182.4
387,7
88.8
141.0
14.8
M.1
0.0
7.88
84.64
0.00
8.37
8.08
O.QO
3.44
1.38
0.00
0.82
3.47
0.00
1.30
0.38
0.00
0.14
eso
IDLE
4.0
414.B
eono
805.3
77.8
63,3
33.e
28.41
0.63
1.33
1.18
0.38
0.88
0.48
0.24
0.3S
0.31
0.47
0.87
0.80
0.07
0.10
0.09
SOO
BRAKE
SB.O
1S.B
842.1
83.3
142.8
12.8
3.8
0.0
1.48
0.83
0.00
0.20
0.28
o.ao
0.11
0.03
0.00
0.01
0.08
0.00
0.03
0.01
0.00
0.00
OFF
0.0
0.0
0.0
0.0
0.0
0.0
32.8
44.B
40.14
O.OO
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
o.oo
EMI88ICNS, LB/Mfl
100.0
100.0
100.0
34.B
8.2
17.0
14.0
3.3
7.4
2.2
0.7
1.2
8.8
1.4
3.0
0.8
0.2
0.4
EMI88I0NS, 14/1000 ML
403
637
433
83
108
73
182
228
177
17
40
22
r
EMO BOO
1
88.7
7.8
804.7
3S.3
83.1
8.1
4.8
B.B
7.78
0.38
0.78
0.81
0.23
0.48
0.37
0.01
0.03
0.02
0.03
O.OB
0.06
0.00
0.01
0.00
800
2
189.0
23.1
809.8
18.8
89.2
11.2
2.4
4.8
3.80
0.88
1.11
O.BO
0.34
0.88
0.88
0.01
0.02
0.02
0.03
O.OB
O.OB
0.01
0.01
0.01
800
3
227.3
82.3
870.0
17.8
42.6
10.1
1.8
3.8
3.10
0.82
1.24
1.00
0,38
0.72
0.88
0.01
0.02
0.02
0.03
0.08
0.04
0.01
0.01
o.ot
800
4
931,4
47.1
814.0
1B.8
83.2
12.4
4.B
1.8
3.01
2.28
O.SO
1.42
1.38
0.66
0.87 .
0.04
0.01
0.02
o.ta
0.08
0.10
0.03
0.01
0,02
800
B
410.4
88.3
880.B
13.8
70.1
18.8
1.B
1.0
1.32
1.18
0.68
0.77
0,88
0.33
0.4S
0.02
0.01
0.01
0.08
0,04
0.08
O.OS
0.C1
0.01
800
B
884.0
78.7
830.0
13.0
128.3
18.0
1.8
1.0
1.32
1.61
0.78
1.04
0,80
0.40
0.68
0.02
0.01
0.01
0.18
0.10
0.13
0.02
0.01
0.02
800
7
748,0
108.4
847.3
14.7
134.8
18,7
2.4
0.0
0.80
2.87
O.OO
0.88
1,41
0.00
0.83
0.04
0.00
0.01
0.38
0.00
0,13
0.08
0.00
o.oa
BOO
8
838.0
128.2
822.8
10.4
00.4
11.6
20.1
c.o
7.88
28.41
0.00
8.8S
13.28
0.00
8.08
0.42
0.00
0.1S
e.ao
0.00
0.87
o.ea
0.00
0.11
800
IOLE
4.0
827.3
80.3
241,3
13.1
23.3
33.2
28.44
0.83
1.33
1.18
0.48
0.70
0.82
0.08
0.12
0.10
0.22
0.32
0.28
0.01
o.oe
0.0?
800
BRAKE
SB.O
13.8
814.0
16.6
83.2
12.4
3.8
0.0
1.48
0.83
0.00
0.20
0.33
0.00
0.12
0.01
0.00
0.00
0.04
0.00
0.01
0.01
0.00
0.00
OFF
0.0
0.0
0.0
0.0
0.0
0.0
32.8
44.8
40.14
0.00
0.00
0.00
0.00
0.00
0.00 .
0.00
0.00
0.00
0.80
0.00
0.00
0.00
o.oo
0.00
100.0 100,0 100.0 35.8 B.B 17.8 18.3 3.8 S.7 0.7 0.8 0.« 3.4 0.7 1.7 0.4 0.1 0.2
837 877 Bid 10 33 22 83 104 87 12 12 is
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