Part II - OFF-HIGHWAY MOBILE SOURCES
INTRODUCTION
This section contains emission rates for eight types of off-highway
mobile sources. The emissions of six of these types of sources are
unchanged from the previous edition and supplements. Changes have been
made inboard powered vessels and diesel powered heavy-duty construction
equipment. The changes for these two sources are summarized below.
Inboard Powered Vessels - Only one item has been changed since the
previous edition. This change was the deletion of the 1550 horsepower
diesel emission factors from Table II-3.3 because they were for a 1550
horsepower steam engine and not a diesel engine.
Construction Equipment - The emission factors for heavy-duty diesel
construction equipment are based on a recent study by Environmental
Research and Technology, Inc. Some of the categories of construction
equipment have changed. The emission factors for heavy-duty gas powered
construction equipment are the same as in the previous edition.
Comments on Other Studies - Recently there have been two studies
undertaken for off-highway mobile sources. The first one deals strictly
with inboard powered vessels, and is entitled "Emission Factor
Documentation for AP-42: Section 3.2.3 Inboard Powered Vessels" (EPA
450/4-84-001). The second report discusses locomotives, construction
equipment and inboard powered vessels, and is entitled "Recommended
Revisions to Gaseous Emission Factors for Several Classes of Off-Highway
Vehicles - Final Report" (EPA 460/3-85-004, March 1985). The following
are EPA's comments on material presented in these reports relative to
AP-42.
Locomotives - The current emission factors for locomotives are based on
tests of three in-use locomotives. The second report located data on at
least fifteen new locomotives, and recommended updating the emissions to
this new data set. The report also suggested that the duty cycle for
locomotives include some engine shut-down in place of some engine idle,
mostly based on the fact that fuel costs are higher and companies would
encourage engine shut-down as a cost saving measure. The previous
emission factors do not assume any engine shut-down during the duty
cycle. EPA has not adopted the new emission factors, and instead has
retained the previous emission factors for two reasons. First, there
does not appear to be any verifiable basis for picking the percent of
engine shut-down time during the duty cycle. Second, EPA has become
aware of a larger data set of in-use locomotives with emission data. EPA
intends to analyze these data in the near future, and feels it would be
inappropriate to update the locomotive emission factors with the fifteen
locomotives on an interim basis, only to change them at a later date.
Inboard Powered Vessels - The first report compiled available data on
inboard powered vessels and attempted to estimate the emission factors.
H-i
-------
The second report critiqued the first report, and found some
inconsistencies in the manner in which the emission factors were
estimated. The second report recommended only two changes to the
existing emission factors — one was the removal of the 1550 horsepower
emission rates from Table II-3.3. (This engine was a steam boiler, and
not diesel powered as presented.) This we have done. The second was
the addition of some new emission rates for diesel engines above 3000
horsepower, but at only one load setting and in units which were
inconsistent with those in Table II-3.2. EPA investigated the
possibility of converting the new data into the old units but had no
basis for estimating the appropriate conversion factor. Therefore, the
previous emission factors (at 3600 horsepower) are retained.
Future Work - Beside locomotives, EPA may also soon undertake a study of
emissions from new aircraft. Emission standards for new aircraft took
effect in 1984; therefore, all 1984 and newer aircraft should have lower
emissions than the rates presented herein. However, the present emission
rates for aircraft are sufficient for now, since the majority of aircraft
in use are pre-1984 uncontrolled technology.
Il-ii
-------
II- 1 AIRCRAFT
II- 1.1 General
Aircraft engines are of two major categories, reciprocating piston
and gas turbine.
In the piston engine, the basic element is the combustion chamber,
or cylinder, in which mixtures of fuel and air are burned and from which
energy is extracted by a piston and crank mechanism driving a propeller.
The majority of aircraft piston engines have two or more cylinders and
are generally classified according to their cylinder arrangement -
either "opposed" or "radial". Opposed engines are installed in most
light or utility aircraft, and radial engines are used mainly in large
transport aircraft. Almost no singlerow inline or V-engines are used in
current aircraft.
The gas turbine engine usually consists of a compressor, a combus-
tion chamber and a turbine. Air entering the forward end of the engine
is compressed and then heated by burning fuel in the combustion chamber.
The major portion of the energy in the heated air stream is used for
aircraft propulsion. Part of the energy is expended in driving the
turbine, which in turn drives the compressor. Turbofan and turboprop
(or turboshaft) engines use energy from the turbine for propulsion, and
turbojet engines use only the expanding exhaust stream for propulsion.
The terms "propjet" and "fanjet" are sometimes used for turboprop and
turbofan, respectively.
The aircraft in the following tables include only those believed to
be significant at present or over the next few years.
Few piston engine aircraft data appear here. Military fixed wing
piston aircraft, even trainers, are being phased out. One piston
engine helicopter, the TH-55A "Osage", sees extensive use at one train-
ing base at Ft. Rucker, AL (EPA Region IV), but engine emissions data
are not available. Most civil piston engine aircraft are in general
aviation service.
The fact that a particular aircraft brand is not listed in the
following tables does not mean the emission factors cannot be calculated.
It is the engine emissions and the time-in-mode (TIM) category which
2/HO Internal Omil>n>lioti En^im- Sources. II-1-1
-------
determine emissions. If these are known, emission factors can be
calculated in the same way that the following tables are developed.
The civil and military aircraft classification system used is shown
in Tables II- 1-1 and II- 1-2. Aircraft have been classified by kind of
aircraft and the most commonly used engine for that kind. Jumbo jets
normally have a miximum of about 40,000 pounds thrust per engine, and
medium range jets about 14,000 pounds thrust per engine. Small piston
engines develop less than 500 horsepower.
II- 1.2 The Landing/Takeoff Cycle and Times-in-Mode
A landing/takeoff (LTO) cycle incorporates all of the normal
flight and ground operation modes (at their respective times-in-mode),
including: descent/approach from approximately 3000 feet (915 m) above
ground level (AGL), touchdown, landing run, taxi in, idle and shutdown,
startup and idle, checkout, taxi out, takeoff, and climbout to 3000 feet
(915m) AGL.
In order to make the available data manageable, and to facilitate
comparisons, all of these operations are conventionally grouped into
five standard modes: approach, taxi/idle in, taxi/idle out, takeoff and
climbout. There are exceptions. The supersonic transport (SST) has a
descent mode preceding approach. Helicopters omit the takeoff mode.
Training exercises involve "touch and go" practice. These omit the
taxi/idle modes, and the maximum altitude reached is much lower. Hence,
the duration (TIM) of the approach and climbout modes will be shorter.
Each class of aircraft has its own typical LTO cycle (set of TIMs).
For major classes of aircraft, these are shown in Tables II- 1-3 and
II-1-4. The TIM data appearing in these tables should be used for
guidance only and in the absence of specific observations. The military
data are inappropriate to primary training. The civil data apply to
large, congested fields at times of heavy activity.
All of the data assume a 3000 foot AGL inversion height and an
average U.S. mixing depth. This may be inappropriate at specific
localities and times, for which specific site and time inversion height
data should be sought. Aircraft emissions of concern here are those
released to the atmosphere below the inversion. If local conditions
suggest higher or lower inversions, the duration (TIM) of the approach
and climbout modes must be adjusted correspondingly.
A more detailed discussion of the assumptions and limitations
implicit in these data appears in Reference 1.
Emission factors in Tables II- 1-9 and II- 1-10 were determined
using the times-in-mode presented in Tables II- 1-3 and II- 1-4, and
generally for the engine power settings given in Tables II- 1-5 and
II- 1-6.
II- 1-2 EMISSION F\< TORS 2/KO
-------
Table II- 1-1. CIVIL AIRCRAFT CLASSIFICATION3
Aircraft
Engine
No.
Mfg.
Type Model/Series
Supersonic transport
BAC/Aerospatiale Concorde 4
Short, medium, long range
and jumbo jets
BAC 111-400 2
Boeing 707-320B 4
Boeing 727-200 3
Boeing 737-200 2
Boeing 747-200B 4
Boeing 747-200B 4
Boeing 747-200B 4
Lockheed L1011-200 3
Lockheed L1011-100 3
McDonnell-Douglas DC8-63 4
McDonnell-Douglas DC9-50 2
McDonnell-Douglas DC10-30 3
Air carrier turboprops -
commuter, feeder line and
freighters
Beech 99 2
GD/Convair 580 2
DeHavilland Twin Otter 2
Fairchild F27 and FH227 2
Grumman Goose 2
Lockheed L188 Electra 4
Lockhead L100 Hercules 4
Swearingen Metro-2 2
Business jets
Cessna Citation 2
Dassault Falcon 20 2
Gates Learjet 24D 2
Gates Learjet 35, 36 2
Rockwell International
Shoreliner 75A 2
Business turboprops
(EPA Class P2)
Beech B99 Airliner 2
DeHavilland Twin Otter 2
Shorts Skyvan-3 2
Swearingen Merlin IIIA 2
General aviation piston
(EPA Class PI)
Cessna 150 1
Piper Warrior 1
Cessna Pressurized
Skymaster 2
Piper Navajo Chieftain 2
RR
RR
P&W
P&W
P&W
P&W
PiW
RR
RR
RR
P&U
P&W
GE
PWC
All
PWC
RR
PWC
All
All
GA
PiW
GE
GE
GE
GE
PWC
WC
GA
GA
Con
Lye
Con
Lyn
TF
TF
TF
TF
TF
TF
TF
TF
TF
TF
TF
TF
TF
TP
TP
TP
TP
TP
TP
TP
TP
TF
TF
TJ
TF
TF
TP
TP
TP
TP
Olymp. 593-610
Spey 511
JT3D-7
JT8"D-17
JT8D-17
JT9D-7
JT9D-70
RB211-524
RB211-524
RB211-22B
JT3D-7
JT8D-17
CF6-50C
PT6A-28
501
PT6A-27
R. Da. 7
PT6A-27
501
501
TPE 331-3
JT15D-1
CF700-2D
CJ610-6
TPE 731-2
CF 700
PT6A-27
PT6A-27
TPE-331-2
TPE-331-3
0-200
0-320
TS10-360C
T10-540
.References 1 and 2.
Abbreviations: TJ - tubojet, TF - turbofan, TP - turboprop, R -
reciprocating piston, 0 - opposed piston. All - Detroit Diesel Allison
Division of General Motors, Con - Teledyne/Continental, GA - Garrett
AiResearch, GE - General Electric, Lye - Avco/Lycoming, P&W - Pratt &
Whitney, PWC - Pratt & Whitney Aircraft of Canada, RR - Rolls Royce.
Internal <'omltu>ti<>ii Kiiuim- Sourer
II- 1.3
-------
Table TI-1-2. MILITARY AIRCRAFT CLASSIFICATION3
Aircraft
mi ssiun
(Class)
Contba t
Horaber
Transport
I'atrul/Antl.sub
Trainer
Hclicopter
DOD I'opular name
PL* si gnat ion
A-4
A-7
F-4
F-5
F-14
F-15A
F-16
B-52
Skyhawk
Corsair 2
Phantom 2
Freedom Fighter/
Tiger 2
Tomcat
Eagle
Stratofortress
Power plant
Manufacturer
Service
No. 4 Type
Mc[»-Doug
Vought
MeD-Doug
Northrop
CruBHan
MeD-Doug
CD/FW
Boeing
C-SA
C-130
KC-135
C-141
P-3C
S-U
T-34C
T-38
UH-1H
Hll- 3
CII-47
Calaxy
Hercules
Stratotanker
Starl if ter
Orion
Viking
Turbo Mentor
Talon
Iroquois/Huey
Sea King/Jolly
(ireen Giant
Chinook
GELAC
GELAC
Boeing
GELAC
CALAC
CALAC
Beech
Northrop
Bell
Sikorsky
Hoeing Vertol
USN, USMC 1 TJ
USN 1 TF
USAF, USN 2 TJ
USAF 2 TJ
USN 2 TF
USAF 2 TF
USAF 1 TF
USAF 8 TJ. TF
USAF 4 TF
USAF, USN, USCC 4 TP
USAF 4 TJ
USAF 4 TF
USN A TP
USN 2 TF
USN 1 TP
USAK 2 TJ
USA, USN 1 TS
USAF, USN, USCC 2 TS
USA 2 TS
Mfg.'
Designation
P&W
All, P&W
CE
CE
P&W
P&W
P&W
J52, J65
TF41, TF30
J79
J85
TF30, F401
FIDO
FIDO
P&W
GE
All
P&W
P&W
All
CE
PWC
CE
Lye
J57, TF33
TF39
T56
J57
TF33
T56
TF34
PT6A
J85
Lye, GE T53, T58
CE T58
T55
Reference 1. USN - U.S. Navy, USMC - U.S. Marine Corps, USAF - U.S. Air Force, USCG - U.S. Coast CuaYd, USA - U.S. Array.
Abbreviations: All - Detroit Diesel Allison Division of General Motors, CALAC - Lockheed - California, GD/FW - General Dynamics,
Ft. Worth, CE - General F.lec-tric, (;EI.AC - Lockheed-Georgia, Lye - Lyconing, McD-Doug - McDonnell Douglas, P&W - Pratt & Whitney,
I'WC - Pratt & Whitney Aircraft of Canada.
CTJ - Turbojet, TF - Turbofan, TP - Turboprop, TS - Turboshaft.
II- 1-4
EMISSION FACTORS
2/80
-------
Table II-1-3. TYPICAL DURATION FOR CIVIL LTO CYCLES
AT LARGE CONGESTED METROPOLITAN AIRPORTS3
Aircraft
Commercial
carrier
Jumbo, long
and medium
range j et°
Q
Turboprop
Transport-
piston
General
aviation
Business jet
Turboprop
Piston
Helicopter
Taxi/ Takeoff
Idle out
19.0 0.7
19.0 0.5
6.5 0.6
6.5 0.4
19.0 0.5
12.0 0.3
3.5
Mode
Climbout
2.2
2.5
5.0
0.5
2.5
5.0
6.5
Approach
4.0
4.5
4.6
1.6
4.5
6.0
6.5
Taxi/
Idle in
7.0
7.0
6.5
6.5
7.0
4.0
3.5
Total
32.9
33.5
23.2
15.5
33.5
27.3
20.0
, Reference 3. Data given in minutes.
Same times as EPA Classes T2, T3 and T4 (Note b, Table II-1-5) .
"rSame times as EPA Classes Tl and P2 (Note b, Table II-1-5) .
Same times as EPA Class PI (Note b, Table II- 1-5).
2/80
Internal < <>ml>u>tioM Ennirn- Sourer
II- I-S
-------
Table II-1-4. TYPICAL DURATION FOR MILITARY LTO CYCLES'
Aircraft TIMb
Mode
Code
Combat
USAF 1
USNd 2
Trainer -
Turbine
USAF T-38 3
USAF general 4
USNd 2
Transport -
Turbine
USAF general 5
USNf 6
USAF B-52
and KC-135 7
Military -
Piston 8
Military -
Helicopter 9
Taxi/ Takeoff
Idle out
18.5 0.4
6.5 0.4
12.8 0.4
6.8 0.5
6.5 0.4
9.2 0.4
19.0 0.5
32.8 0.7
6.5 0.6
8.0
Climbout
0.8
0.5
0.9
1.4
0.5
1.2
2.5
1.6
5.0
6.8
Approach
3.5 •
1.6
3.8
4.0
1.6
5.1
4.5
5.2
4.6
6.8
Taxi/
Idle in
11.3
6.5
6.4
4.4
6.5
6.7
7.0
14.9
6.5
7.0
Total
34.5
15.5
24.3
17.1
15.5
22.6
33.5
55.2
23.2
28.6
Reference 1. Data given in minutes. USAF - U.S. Air Force, USN - U.S.
Navy.
TIM Code defined in Table II-1-5.
£
.Fighters and attack craft only.
Time-in-mode is highly variable. Taxi/idle out and in times as high as
25 and 17 minutes, respectively, have been noted. Use local data base if
possible.
Includes all turbine craft not specified elsewhere (i.e., transport,
,cargo, observation, patrol, antisubmarine, early warning, and utility).
Same as EPA Class P2 for civil turboprops.
II-
EMISSION FACTORS
2/80
-------
Table 11-1-5. ENGINE POWER SETTINGS FOR TYPICAL EPA
LTO COMMERCIAL CYCLES3
Mode
Taxi/Idle (out)
Takeoff
Climbout
Approach
Taxi/Idle (in)
Power
Class Tl,
Idle
100
90
30
Idle
setting (% thrust
P2b Class T2.T3
Idle
100
85
30
Idle
or horsepower)
, T4b Class Plb
Idle
100
75 - 100
40
Idle
Helicopter
Undefined
a.
References 1 and 3.
As defined by EPA (Reference 3):
Class Tl is all aircraft turbofan or turbojet engines except Class T5
of rated power less than 8000 Ibs thrust.
Class T2 is all turbofan or turbojet aircraft engines except Classes
T3, T4 and T5 of rated power of 8000 Ibs thrust or greater.
Class T3 is all aircraft gas turbine engines of the JT3D model family.
Class T4 is all aircraft gas turbine engines of the JT8D model family.
Class T5 is all aircraft gas turbine engines on aircraft designed to
operate at supersonic speeds.
Class PI is all aircraft piston engines, except radial.
Class P2 is all aircraft turboprop engines.
Table II- 1-6. ENGINE-POWER SETTINGS FOR A TYPICAL LTO
MILITARY CYCLE3
Mode
Taxi/Idle (out)
Takeoff
Climbout
Approach
Taxi/Idle (in)
Power setting
Military
transport
Idle
Military
90 - 100
30
Idle
(% thrust or
Military
jet
Idle
horsepower)
Military
piston
5-10
Military
helicopter
Idle
Military or
Afterburner 100
Military
84 - 86
Idle
75
30
5-10
60 - 75
45 - 50
Idle
Reference 1.
2/HO
Internal (.om)ui>linn Kn^inc Source
II-1-7
-------
TABLE U-l-7. MODAL EMISSION RATES-CIVIL AIRCRAFT ENGINES"
Model -Seriett
Mfgb Typeb
ZSOB17B
All. TP
501D22A
All. TP
TPE 331 -i
GA TP
TPE331-2
GA TP
TPE 731-2
GA Tr
CJ 61U-2C
GE TJ
CF70U-2D
GE TF
CF6-6D
GE TF
CF6-50C
GE TF
Mode
Idle
Takeoff
Climboul
A pproach
Idle
Takeoff
Chmbout
Approach
Idle
Takeoff
Climbout
Approach
Idle
Takeoff
Climbout
Approach
Idle-
Take-off
C Umbout
Approach
Idle
Takeoff
Climbout
A pproach
IdU-
Takeoff
Climbout
Approach
Idle
Takeoff
Climbout
A pproach
Idle
Takeoff
Chmbout
Approach
Fuel Rate
Ib/hr
63
26j
85
610
2J76
2198
1 140
1 12.0
4btt.O
4U9.0
250.0
105.0
405.0
372 0
220.0
181.0
1552.0
1385.0
S21.0
510.0
2780 .0
2430.0
1025.0
460
2607
2322
919
1063
13750
1 1329
3864
1206
18900
15622
5280
kg/hr
28.58
120.2
1111
38.56
276.7
1078
997
SIM
bO.tt
20?. 7
185.5
113.4
47.6
183.7
168.7
99.8
82.1
704.0
628.2
236.3
231.3
1261.0
1 102.0
464.9
208.7
1 182
1053
416.9
482.2
6237
5139
1753
547
8573
7104
2395
CO
lu/hr
6.13
2.07
2 21
4.13
26.60
4 85
4.53
5.81
6 89
0.350
0.40(1
1.74
6.73
0 38
0.51
3.65
11.11
1.B6
1.80
9.53
79.05
75.06
65.61
90.20
/I. 30
.57.35
5b 05
56.9B
65.06
8.25
6.80
23 18
88.04
0.38
4.70
22.70
kg/l.r
2 78
0.939
1.00
1.87
12.07
2.20
2.05
2.64
3.12
0.159
0. 181
0.789
3.05
0.172
0.231
1.66
5.04
0.844
0.816
4.32
35.86
34.05
29.76
40.91
32.34
26.01
26.33
25.X.5
29.51
3.74
3.03
10.61
39.93
0.172
2.13
10.30
NO',
Ib/hr
0.09
1.75
1.46
0.19
2.15
21.10
20.27
8.54
0.320
5 66
4.85
2 48
0.27
4.14
3.6^
1.82
0.54
29.8
23.68
3.59
0.46
11.68
8.99
1 54
041
14.60
9.98
1,65
4.88
467.5
309.2
41.54
3.02
670.95
462.0
52.8
kg/hr
0.041
0.794
0.662
0.086
0.975
9.57
9. 19
3.87
0. 145
2.57
2.20
1.12
0.22
1 88
1.67
0.826
0,245
13.52
10.74
1.63
0.209
5.30
4.08
0.6V8
0. 186
6 62
4.53
0.748
2.21
212.1
140.2
18.84
1.37
304.3
209.6
23.95
a
ToUl HC
Ib/hr
1.27
0.07
0.09
0.44
10.74
0.67
1.96
223
8 86
0.050
0.060
0.160
9 58
0. 16
0.15
0.59
4.05
0.14
0.12
1.51
9.18
0.28
0.49
2,77
8.28
0.26
0.23
1.29
21.79
B.25
6.80
6.96
36.18
0.19
0.16
0.05
Wg/hr
0.576
0.032
0.041
0.200
4.87
0.304
0.889
1.01
4 02
0.023
0.027
0.073
4.34
0.072
0.068
0.268
1.84
0.064
0.054
0 685
4.16
0.127
0.222
1.26
3.76
0.118
0.104
0.585
9.88
1.74
3.08
J.16
16.41
0.086
0.073
0.021
SOx Particular/
0.06
0.27
0.25
0.09
0.61
2.38
2 20
1.14
0.11
0.46
0.41
0.25
0.11
0.41
0.37
0.22
0.18
1.55
1.39
0.52
0.51
2.78
2.43
1.03
0.46
2.61
2.32
0.92
1.06
13.75
11.33
3.86
1.21
18.90
15.62
5.28
kg/hr Ib/hr kg/hr
0.03
0.12
0.1 1
0.04
0 28
1.08
1.00
0.52
0.05 0.3* O.I48
0.21 08 0.36
0.19 0.6 0.27
0.11 0.6 027
0.05 (A«»ume 331-3
0.18 data)
0.17
0.10
0.08
0.70
0.63
0.24
0.23
1.26
1.10
0.46
0.21
1.18
1.05
0.42
0.48 0.04* 0.02*
6.24 0.54 0.24
5.14 0.54 0.24
1.75 0.44 0.20
0.55 (A'lume CF6-6D
8.57 data)
7.10
2.40
II- I-K
EMISSION FACTORS
-------
TABLE II-1-7 (CONTINUED)
Model-Seriei
Mfgb Typeb
JT3D-7
PfcW TF
JT8D-17
PfcW TF
JT9U-7
P4.W TF
JT9D-70
PJ
-------
TABLt II-1-7 (CONTINUtD)
Model-Serie*
Mfgb Type6
RB-211-22B1
RR Tf
RB-21I -5241
RR TF
HK-401-061
RR TF
Dart RDa7'
KI( IP
1'yneK- '
RR TH
Olympus 593'
MK610
RR (Brintol)
0-200
Con. O
TSIO-360C
Con. O
6-285-B
(Tiara)
Con. O
Mode
Idle
Takeoff
Climbout
Approach
Idle
Takeoff
Climbout
Approach
Idle
Takeoff
C limbout
Approach
Idle
Takeoff
Climbout
Approach
Idle
Takeoff
Climbout
Approach
Idle
Takeoft
Climbout
Descent
Approach
Idle
TaKeoff
Climbout
Approach
IdU
Takeoff
C limbout
Approach
Idle
Takeoff
Climbout
Approach
Fuel
Ib/hr
1718
14791
12205
4376
1769
17849
1468ft
5450
330
2400
2130
775
41 1
1409
1248
645
b!9
2372
2188
1095
3060
52200
19700
5400
9821
8.24
45.17
45.17
25.50
1 1.5
133.
99.5
61.0
72.12
153.0
166.0
83.5
Rate
kg/hr
779.3
6709
5536
1985
802.4
8096
6662
2472
149.7
1089
966.2
351.5
186.4
639.1
566 1
292.6
280.8
1076
922.5
496.7
1388
23673
8936
2449
4455
3.75
20.53
20 51
11.59
5.21
60.3
45.1
27.7
10.03
69.39
52.61
37.88
Ib/hr
137.6
5.62
14.89
93.78
35.91
7.32
7.34
11.72
10.07
2.40
2.77
5 04
37.61
4.79
4 26
21.48
40.79
1.21
1.29
1 1 30
342.7
1513.8
275.8
426.6
451.8
•> M
44 0
44.0
30.29
6.81
143.9
95.6
60.7
26.23
152 7
110.9
85.39
CO
kg/hr
64.42
2.55
6.75
42.54
16.29
3.32
3.33
5.32
4.57
1.09
1.26
2.29
17.06
2.17
1 .91
9.74
18.50
0.549
0.585
5.13
155.4
686.5
125.1
193.5
204.9
242
21) o
20.0
13.75
3.09
65.3
43.4
27.5
11.90
69.3
50.3
38.77
NO
Ib/hr
5.31
504.1
301.9
32.26
4.74
660.4
470.0
62.89
0.825
30.0
24.07
3.88
0.292
8.51
5.55
0.568
0.477
27.11
25.23
9.00
9.72
542.9
169.4
18.9
41.25
0.013
0.220
0.220
0.029
0.022
0.36
0.43
0.23
0.0334
0.899
0.913
0.394
c
X
kg/hr
2.41
228.7
136.9
14.63
2.15
299.6
213.2
28.53
0 )74
11 61
10. 92
1.76
0 132
3. Hi.
2.52
0.258
0.216
12.30
11.44
4.08
4.41
246.2
76.84
8.6
18.71
0.006
0.100
0. 100
0.013
0.009
0. 16
0.20
0.10
0.0152
0.408
0.41-4
0.179
Total
Ib/hr
100.1
29.14
8.30
32.16
5.43
1.96
2.50
0.545
0.924
0 120
0.107
0.155
25.52
8.75
2.15
0.0
6.63
2.87
263
2.68
119.3
151.4
31.52
132.3
93.30
0.239
0.940
0.940
0.847
1.59
1.22
0.95
0.69
0.773
1.78
1.39
1.343
HCd
kg/hr
45.36
13.22
3.76
14.59
2.46
0.889
1.13
0.247
0.419
0.054
0.049
0.070
1 1.58
3.97
0.975
0.0
3.01
1.31
1.19
1.22
54.11
68.7
14.30
60.0
42.32
0.107
0.427
0.427
0.385
0.723
0.55
0.43
0.31
0.350
0.806
0.632
0.609
so;
Ib/hr
1.72
14.79
12.21
4.38
1.77
17.85
14.69
5.45
0.33
2.40
2.13
0.78
0.41
1.41
1 25
0.65
0.62
2.37
2.19
1.10
3.06
52.2
5.4
9.82
0.0
0.01
0.01
O.U1
0.0
0.03
0.02
0.01
0.0
0.03
0.02
0.02
e
it Particulatei'
kg/hr Ib/hr kg/hr
0.78
6.71
5.54
1.99
0.80
8.10
6.67
2.47
0.15
1.09
0 97
0.15
0.19
(I 64
0.57
0.2')
0.28
1 OH
0.99
0.50
1.39
23.7
8.94
2.4
4.46
0
0
0
0
0.0
0.01
0.01
0.01
0.0
0.01
0.01
0.01
ir- i-io
EMISSION FACTORS
2/80
-------
TABLE 11-1-7 (CONCLUDED)
Model-Seriea
Mfe? Typcb
O-320
Lye. O
1O-320-DIAD
Lye. O
1O-360-H
Lye. O
TIO-540-
J2U2
Lye. O
Mode
Idle
Takeoff
Climbout
Approach
Idle
Takeoff
Climbout
Approach
Idle
Takeoff
Cltmbout
Approach
Idle
Takeoff
Climbout
Approach
Fuel
Ib/hr
9.46
89.1
66.7
46.5
7.84
91.67
61.42
37.67
8.09
103.0
71.7
36.6
25.06
259 7
204.5
99.4
Rate
kg/hr
4.30
40.4
30.3
21. 1
3.56
41.57
27.85
17.08
3.68
46.7
32.5
16.6
1 1.36
M7.8
92.7
45.1
Ib/hr
10.21
96.0
66.0
56.8
4.86
109.3
54.55
35.57
7.26
123.5
70.5
25.3
32.42
374.5
300.8
125.4
CO
kg/hr
4.63
43.5
29.9
25.8
2.20
49.55
24.74
16.13
3.29
56.0
32.0
11.5
14.70
169-8
136.4
56.9
NO',
Ib/hr
0.0049
0.195
0.265
0.044
0.009
0.167
0.344
0.128
0.0094
0.205
0.329
0.372
0.0097
0.094
0.0481
0.138
kg/hr
0.0022
0.088
0.120
0.020
0.0041
0.0756
0.156
0.058
0.0042
0.093
0.149
0.169
0.0044
0.043
0.0218
0.0623
Total
Ib/hr
0.350
1.05
0.826
0.895
0.283
1.047
0.588
0.460
0.398
1.03
O.S85
0.355
1.706
3.21
3.40
133
HCd
kg/hr
0.159
0.475
0.375
0.406
0.128
0.475
0.267
0.208
0.180
0.469
0.265
0.161
0.774
1.46
1.54
0.604
soe
Ib/hr
0.0
0.02
0.01
0.01
0.0
0.02
0.01
0.01
0.0
0.02
0.01
0.01
0.01
0.05
0.04
0.02
kg/hr
0.0
0.0)
0.01
0.0
0.0
0.01
0.01
0.0
0.0
0.01
0.01
0.0
0.0
0.02
0.02
0 01
ParticuUte*
Ib/hr kg/hr
JKeri:rtmces 1,2.
Abbreviations: All — Detroit Diesel AlUiun Division of General Motors; Con — Teledyne/CunUnental; GA — Garrett AiReaearch; GE — General Elei trie;
l.yi. - Avco/Lycoming; Hi, W - Pratt & Whitney; HWC — Hratl L Whitney Aircraft of Canada: RR — Rolls Koyce; TJ - Turbojet; TF - Turbofan;
TF — Turboprop; O ~ Reciprocating (Piaton) Opposed.
Nitrogen oxide* reported aa NO.,.
'' 1'olul hyifrc.tjrlmns. Volatile organics, including unhurried hydrocarbons and organic pyrolysjs produces.
^Sulfur oxides and suUuric acid reported an SO2. Calculated from fuel rate and 0.05 wt% sulfur in Jet A and Jet B fuel, or 0.01 wt% aulfur in aviation
gasoline, i'or turbine engines, the conversion IE therefore SOK (Ib/hr) - 10'3 (fuel rate), and for piston engines, the conversion ia SOX (Ib/hr) - 2 x 10
(fuel rate).
'.Ml paniculate data are from Reference 4. Does not include condensihle compounds.
I'he indicated reference doea not apeciiy aeries number for thia model engine.
"Diluted sniokclets" JT 8D. Note: JT8U is a turbofan engine and i» not equivalent to the JT8 (Military _T52J turbojet engine.
'All Kolls Hoyce data arc based upon an arbitrary 7% idle, which dues not reflect I he actual situation. In reality, Rolls Koyce engines will idle at 5-6%
with correspondingly higher emissions (Keterence 2).
i I he < Hyinpiib SUJ engine used in the Concorde SS I h.ii a unique 6-mode IK) cycle.
2/80
Internal ('oniJMi.-tioii Eiiijiiic
11- I -1 i
-------
TABLE II- 1-8. MODAL EMISSION RATES - MILITARY AIRCRAFT ENGINES3
Model-Seriei
(Civil Version)
Mlg'1 Typ«h
Mode
Fuel
CO
NO
Toul HC
SO"
Ib/hr
Ib/hr
Ib/hr
kg/h.
Ib/hr
Ib/hr
kg./br
Paniculate*
Ib/hr k^
J57-l>-22
(JT3C)
P«.W TJ
J65-W-20
Wr. TJ
J79-GE-IO
CE fj
JB5-GF.-5F
GK TJ for T 38
JHS-CU. -21
GrJ 1J for F-5
Tr 30-1>-6H
IJF; id)
H(.W IF
fur A-7
TK 30-I>-.*I2A
(Jr 1 10AI
1-k.W TJ
fur F-14
TF33-H-3/5/7
UT;D»
PfcW TJ
TF34-GE-400
GE TJ
Idle
Til-toff
Climbout
A pproach
Idle
Takeoff
Chmbout
A pp roach
Idle
Tikcoff
C luiibout
Approach
Idle
Takiof!
Clmtbout
A pproach
Idle
'lokiuff
Cliniiiuul
A ^preach
l.lle
T«k..-o(f
C Itrnlioul
A purortt h
l
-------
TABLE II-1 -8 (CONCLUDED)
Mijdcl -Series
(Civil- Vernun)
Mf,?h Typeh
TKJ9-GE-1
(JT4A)
GE TJ
TK41-A-2
All. TF
KIOO-I'W- 100
(Jlf 22)
Pt,W TF
PT6A-27
PWC TH
All Tl'
T^ (-L- 1 IU
ILK.. 1)
l.yt TSi
TfS-L-1 1A
I1.1C-I)
L>. IS
7;?'™''*
Mode
Ulc
Takeoif
C. Liintumt
Approach
Idie
T-ikeolf
Climbuut
Approach
Idle
Taktoff
Clinibout
Approach
Idle
Takruff
C Imtbout
A pproach
Idle
Tak(.-o(f
C. limbout
A jj[ i oach
Idle .
t. Inr.Liiut
Approach
Idle ;
C li tubout
A ji^.ri J*IL h
Idle
Clirnbuul'
A |Jj) 1'UJ L It
Fuel
Ib/hr
1 130
11410
5740
5740
1070
9040
9040
5314
1060
44200
10400
3000
1 13
425
400
215
548
2079
HOB
142
679
679
133
BB6
886
Rate
ku/ltr
513
5176
2604
2604
405
4101
4101
2410
481
20049
4717
1361
52
193
181
98
249
943
665
478
64
308
308
60
402
402
CO N0b
Ib/hr
75.7
8.0
4.0
40
114.6
14.4
14.4
27.5
20.5
2435 4
18.7
9.0
7 36
0.41
0 48
5.0
17.5
44
4.6
} 7
4.2 ~
2.0
2.0
29.5
14.5
12.9
22.5 ~
5.0
5.0
kg/hr
J4.3
3.6
1.8
1.8
52.0
6.5
65
12.5
9.3
1104 7
6.5
41
3.34
0.20
0 22
2.24
7.9
2.0
21
1.7
1.9
0.9
0.9
13.4
6.6
S.9
10.2
23
2.3
Ib/hr
3.4
JI9.5
160.7
160 7
1.4
201.4
201 4
56.6
4.2
729.3
457.6
33.0
0.28
3 32
2.80
I.BO
2.1
19.3
17. 1,
7.8
0.2
5.0
SO
0.6
18.6
9.1
0.2
6.4
6.4
kg/hr
1.5
144.9
72.9
72.9
0.6
914
91 4
25.7
1.9
330. B
207.6
15.0
0 13
1 51
1.27
0 82
1.0
B 8
H 0
3.5
0.1
2.3
2.3
4.0
8.4
4.1
0.1
2.9
2.9
Total HCC so''
Ib/hr
26.0
2.3
1.1
1.1
70 8
5 3
5.1
12 9
2.4
4.4
0.5
1.8
5 77
0
0
0.47
1 1.5
0 8
0.9
0.5
9.0
0.2
0.2
4.0
0.2
0.3
12.9
0.7
0.7
kg/hr
11.8
1.0
0.5
0.5
32.1
2.4
2.4
5.9
1.1
2.0
0.2
08
2 62
0
0
0 21
5.2
0.4
0.4
U 2
4.
0.
0.
1.6
0.
0.
5.9
0.3
0.3
Ib/hr
II
114
5.7
5 7
11
90
9.0
53
1.1
44 2
10 4
30
0 12
0.43
C 40
0.22
0.5
2.1
0.9
I.I
O.M
0.68
0.6tt
01
0.9
0.9
kg/hr
0.5
5.2
2.6
Ik
05
4.1
4.1
2.4
0 5
20 0
4.7
1.4
0.05
0 20
0 18
0.10
0.2
I 0
04
05
0.06
0.31
0 31
0.05
0.4
0.4
e.f
Paniculate*
Ib/hr
O.J«
17 I*
80*
8.08
0.1*
0.0*
8.6*
1.0*
1.6
3.7
3.0
3.0
0.1
0 8
0.8
kg.'hr
D 1
7.8
3.6
3 6
C 05
0 0
39
0.5
0 7
1-7
1 4
1 4
0 Oi
0.4
0.4
aKf fercnce 1 .
c lolal hydrocarbons. Volatile orgunics, including unhurried hyilrocmhons and organic pyrotysis products.
^Sulfur oxide* and sulfunc acid reported as SO^. Calculated from fuel rate and 0.05 wt% culfur in JP-4 or JP-5 fuel, or 0.01 wt% luUur In iviati'n jjajolir
For turbine enginet. the converiion 11 therefore SOX (Ib/hr) - I0~* (fuel rate), and for pifton engine*, the tonveriion i* SOX (Ib/hr) = 2 x I0-4 (fuel rate).
rlncluile* all "condentible particulatr*." and thu* niay be much higher than colid paniculate* alone [except a* noted
in g below).
''Norn." data are interpolated value* a**umed for calculation*! purpose*, in the absence of experiment*) data.
'Dry particle* only.
''I oi .ihliiL-vi.UKMis, ic-c lootiKili', luhltr 11-1 2.
I.
• l.iki-ntf
lur licli<.o|i|crs.
2/80
Ititfrntil (.onil)ii>linn Eiiuiiu* Sourrrs
II-
-------
TABLE 11- 1-9. EMISSION FACTORS PER AIRCRAFT PER LANDING/TAKEOFF CYCLE-CIVIL AIRCRAFT3
Commercial Carrier
Aircraft
Short, Medium, Long Range
and Jumbo J«t»
BAC/Aeroiipatiale Concorde
BAC 1 11-400
Boeing 707- )20B
Boeing 727-200
Boeing 73/-20U
Boeing 747-200B
Boeing 747 -200ft
Boeing 747-200B
Lockheed LIOI I-20U
Lockheed LIOI 1- 100
McDonnell -Dougl.s DCB-6J
McDonnell-Do. igm DC 9 -50
McDonnell-Don. U» DC 10- 30
Commuter, Feeder Line and
Freighters
Beech 99
GD/Convair 580
DulIavilUii.l Twin Ollrr
Fairchlld r'27 and > 11227
Grunnrian Gooiie
Lockheed LI BO Eleitra
Lockheed L100 Herccile«
Sweanagen Metro-2
b
Power PUnl
No.
4
2
4
3
2
4
4
4
j
3
4
t
3
2
2
2
2
2
4
4
2
Mfg.
RR
RR
1'S.W
HtW
PkW
PLW
1'IW
HR
HH
KH
I'd W
PfcW
GE
PWC
All
PWC
HR
PWC
All
All
GA
CO
Mod.l-S.ru. Ib kg
Olymp 593
Spey 511
JT3D-7
JT8D-I7
JT8D-17
JT9U-7
JT4D-70
IU12I 1-524
HB2II-524
KB21 1-22B
JTJD-7
JT8D-17
CF6-50C
PT6A-28
501
PT6A -27
R.Da.7
PT6A-27
501
501
TPfc 331-3
847.0
103.36
262.64
55.95
37.30
259.64
108.92
66.76
50.07
199 4
262 64
37.30
116.88
7.16
24.38
7.16
36. 26
7.16
48.76
48.76
6.26
384.0
46.8U
119.12
25.38
16 92
117.7*.
4
-------
TABLE II-1-9 (CONCLUDED)
General Aviation
Aircraft
Power Plant CO NO^ Total HC? srf^ ParlicuUtes
No. Mfg. Model-Series Ib kg Ib kg Ib
kg Ib kg Ib kg
But iness Jets
Cessna Citation
Dassault Folcon 20
Gates Learjet 24D
Gate! Learjet 35, 36
Rockwell International
Shoreliner 75A
2
2
2
2
2
PtW
GE
GE
GE
GE
JT1SD-1
CF700-2D
CJ610-6
THE 731-2
CF 700
19.50
76.14
88.76
11.26
76.14
8.85
34.54
40.26
5.11
34.54
2.00
1.68
1.58
3.74
1.08
0.91
0.76
0.72
1.58
0.76
6.72
7.40
8.42
3.74
7.40
3.05
3.36
3.82
1.70
3.36
0.40
0.78
0.84
0.92
0.78
0.18
0.35
0.38
0.42
0.35
Business Turbopropa
[EPA Class P2)
Beech D99 Airliner
DeHavilland Twin Otter
Short* Sky van -3
Swearingen Merlin I1LA
2
2
2
2
PWC
PWC
GA
GA
PT6A-27-
PT6A-27
TPE-331-2
TPE-331-3
7.16
7.16
6.44
6.28
3.25
3.25
2.92
2.85
0.82
0.82
0.883
1.15
0.37
0.37
0.400
0.522
5.08
5.08
8.40
7.71
2.30
2.30
3.81
3.50
O.IR
0.18
0.16
0.16
0.08
o.ob
0.07
0.07
0.46
0.46
0 21
0.21
General Aviation Piaton
(EPA Class PI)
Coin* 150
Piper Warrior
Cessna Pressurized
Skymaater
Piper Navajo Chieftain
Con
Lye
Con
Lye
0-200
0-320
TS10-360C
T10-540
8.32
14.37
33 10
3.77
6.52
15.01
96.24 43.65
0.02
0.02
0.13
0.02
0.01
0.01
0.06
0.01
0.23
0.26
1.15
1.76
0.10
0.12
0.52
0.80
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
"Reference 2.
Abbreviation.: All -Detroit Diesel Allison Division of General Motors; Con - Teledyne/Continental; GA -Garrett AiResearch; GE - General Electric;
Lye - Avco/Lycoming; PliW - Pratl L Whitney; PWC - Pratt b Whitney Aircraft of Canada; RR - Rolls Royce.
CNttrugen oxides reported as NO^
'''I'olal hydrocarbons. Volatile orgjnics, including unburned hydrocarbons and organic pyrolyiix products.
CSullur oxides and sulfurlc acid reported as SO^.
2/80
Internal (.oiiil)ti>li(>ii
Sourer
II- I-IS
-------
Table U-l-10. EMISSIONS FOR MILITARY AIRCRAFT LANDING/TAKEOFF CYCLES3
Aircraft
Power plant
No
Fixed
A-4C
A-7
A-7
B-52H
F-4
F-5
F-14
F-1SA
K-16
C-5A
C-130
Wing - Turbine
Skyhawk
Corsair 2
Corsair 2
Stratofortress
Phantom 2
Freedom
Fighter/Tiger
Tomcat
Eagle
_
Calaxy
Hercules
1
1
1
8
2
2
2
2
1
it
4
KC-135 Stratotanker 4
C-141
T-34C
T-38
P-JC
S3A
Mel ic
LH-IH
Mil- 3
CII-47
Starlifter
Turbo Mentor
Ta 1 on
Orion
Viking
opters - Turbine
Iroquois/Huey
Sea King/.lolly
lireen Cianl
Chinook
4
1
2
4
2
1
2
2
. Model/Series
J65-W-20
TP30-P-68
TF41-A-2
TF-33-P-3/5/8
J79-CK-10
.T85-CK-21
TK30-P-412A
KIOO-PW-100
F100-PW-100
TF39-GE-1
T56-A-7
J57-P-22
TF33-P-3/5/7
PT6A-27
.I85-GE-5F
T56-A-7
TK34-CE-400
TVI-L-111}
T58-CE-5
T55-L-11A
TIMb
code
2
2
2
7
2
1
2
1
1
5
6
7
5
2
3
6
6
9
9
9
CO
Ib
16
11
25
504
32
76
39
54
27
82
32
220
92
1
82
32
34
1
13
20
.62
.10
.79
.08
.24
.64
.88
.40
.20
.12
.36
.92
.40
.73
.72
.36
.18
.•>•)
.54
.94
kg
7.54
5.03
11.70
228.65
14.62
34.76
18.09
24.68
12.34
37.25
14.68
100.21
41.91
0.73
32.99
14.68
15.50
0.70
6.14
9.50
NO c
X
Ib
2.15
2.05
4.83
53.04
10.88
2.10
7.62
29.96
14.98
79.60
9.60
24.64
19.20
0.15
1.22
9.60
4.04
1.19
3.02
6.68
kg
0.98
0.93
2.19
24.06
4.94
0.95
3.46
13.58
6. 79
36.11
4.35
LI. 18
8.71
0.07
0.55
4.35
1.83
0.54
1.37
3.03
Total HCd
Ib
1.10
3.18
15.76
505.76
4.94
10.04
17.36
2.68
1.34
28.08
20.28
185.56
87.68
1.27
10.42
20.28
6.44
2.53
6.78
2.10
kg
0.50
1.44
7.15
229.41
2.24
4.55
7.87
1.22
0.61
12.74
9.20
84.17
39.77
0.58
4.73
9.20
2.92
1.15
3.08
0.95
soe
X
Ib
0.46
0.35
0.52
10.24
1.46
0.76
1.24
2.32
1.16
3.84
1.60
5.36
3.00
0.03
0.62
1.60
1.02
0.20
0.44
kg
0.21
0.16
0.24
4.64
0.66
0.34
0.56
1 .06
0.53
1.74
0.73
2.43
1.36
0.01
0.28
0.73
0.46
0.09
0.20
Particulates
Ib
94.08
33.92
24.24
0.44
0.22
4.12
4.36
31.36
33.00
4.36
0.40
kg
42.67
15.39
11.00
0.20
0.10
1.87
1.98
14.22
14.97
1.98
0.18
Keference I.
Defined in Table "- 1-5.
Nitrogen oxides reported as N0?.
Total hydrocarbons. Volatile organics, including unburned hydrocarbons and organic pyrolysls products.
Sulfur oxides and sulfuric acid reported as S02.
II- !-!(>
EMISSION FACTORS
2/80
-------
II- 1.3 Modal Emission Rates and Emission Factors per LTO Cycle
The first step in the calculation of aircraft emission factors is
the development of a set of modal emission rates. These represent the
quantity of pollutant released per unit time in each of the standard
modes. Each mode is characterized by an engine power setting (given in
Tables II- 1-5 and II- 1-6) and a fuel rate (the quantity of fuel
consumed per unit time).
The following procedure is for calculation of aircraft emission
factors per LTO cycle, starting with engine modal emission rates:
1) For a specific aircraft, determine the number and model of
engines, using for example, Tables II- 1-1 or II- 1-2.
2) Using Table II-1-7 or II- 1-8, locate the appropriate engine
data, and prepare a list of modal emission rates for each mode
m and pollutant p:
m,p
3) Using known military assignment and mission, or civil aircraft
type and application, use Table II- 1-3 or II-1-4 to select
an appropriate set of times-in-mode (TIM) .
4) For each mode m and pollutant p, multiply the modal emission
rate and TIM data for each mode and the sum over all modes.
This will yield an emission factor per engine, which must be
multiplied by the number of engines, N, to produce the emission
factor per LTO cycle, E , for an aircraft:
E = N £ (—) . (TIM)
p at m
m,p
On a conveniently laid out work sheet, this calculation can be set up
easily on a hand calculator with one storage location.
Emission factors calculated in exactly this way are presented in
Tables II-1-9 and II-1-10.
References for Section II- 1
1, D. R. Sears, Air Pollutant Emission Factors for Military and Civil
Aircraft, EPA-450/3-78-117, U.S. Environmental Protection Agency,
Research Triangle Park, North Carolina, October 1978.
2. R. G. Pace, "Technical Support Report - Aircraft Emission Factors",
Office of Mobile Source Air Pollution Control, U.S. Environmental
Protection Agency, Ann Arbor, MI, March 1977.
2/8<) Internal C.omlin>lion Kn^im- Soiirc«-> II-1-17
-------
3. Control of Air Pollution for Aircraft and Aircraft Engines,
38 FR 19088, July 17, 1973.
4. M. Platt, et al., The Potential Impact of Aircraft Emissions upon Air
Quality, APTD-1085, U.S. Environmental Protection Agency, Research
Triangle Park, NC, December 1971.
II-I-IH EMISSION FACTORS j_ Kn
-------
11-2 Locomotives
II- 2.1 General - Railroad locomotives generally follow one of two use patterns: railyard switching or road-haul
service. Locomotives can be classified on the basis of engine configuration and use pattern into five categories:
2-stroke switch locomotive (supercharged), 4-stroke switch locomotive. 2-stroke road service locomotive
(supercharged), 2-stroke road service locomotive (turbocharged), and 4-stroke road service locomotive.
The engine duty cycle of locomotives is much simpler than many other applications involving diesel internal
combustion engines because locomotives usually have only eight throttle positions in addition to idle and
dynamic brake. Emission testing is made easier and the results are probably quite accurate because of the
simplicity of the locomotive duty cycle.
II-2.2 Emissions - Emissions from railroad locomotives are presented two ways in this section. Table [1-2-1
contains average factors based on the nationwide locomotive population breakdown by category. TableII-J-2
gives emission factors by locomotive category on the basis of fuel consumption and on the basis of work output
(horsepower hour).
The calculation of emissions using fuel-based emission factors is straightforward. Emissions are simply the
product of the fuel usage and the emission factor. In order to apply the work output emission factor, however, an
TableII-2-1. AVERAGE LOCOMOTIVE
EMISSION FACTORS BASED
ON NATIONWIDE STATISTICS8
Pollutant
Particulatesc
Sulfur oxidesd
(SOX as S02)
Carbon monoxide
Hydrocarbons
Nitrogen oxides
(NOX asNO2)
Aldehydes
(as HCHO)
Organic acidsc
Average emissions'1
lb/103gal
25
57
130
94
370
5.5
7
kg/103 liter
3.0
6.8
16
11
44
0.66
0.84
Reference 1.
Based on emission data contained in Table n- 2-2
and the breakdown of locomotive use oy engine
category in the United States in Reference 1.
Data based on highway diesel data from Reference
2. No actual locomotive paniculate test data are
available.
Based on a fuel sulfur content of 0.4 percent from
Reference 3.
4/73
Internal Combustion Engine Sources
II-2-1
-------
TaWeII-2-2. EMISSION FACTORS BY LOCOMOTIVE ENGINE
CATEGORY*
EMISSION FACTOR RATING: B
Pollutant
Carbon monoxide
lb/103gal
kg/103 liter
g/hphr
g/m&tric hphr
Hydrocarbon
Ib/IOPgal
kg/103 liter
g/hphr
g/metric hphr
Nitrogen oxides
(NOxasNO2)
Ib/TOPgal
kg/103 liter
g/hphr
g/metric hphr
Engine category
2-Stroke
supercharged
switch
84
10
3.9
3.9
190
23
89
8.9
250
30
11
11
4-Stroke
switch
380
46
13
13
146
17
5.0
5.0
490
59
17
17
I
2-Stroke j 2-Stroke
supercharged
road
66
7.9
1.8
1.8
148
18
4.0
4.0
350
42
9.4
9.4
turbocharged
road
160
19
4.0
4.0
28
3.4
0.70
0.70
330
40
8.2
8.2
4-Stroke
road
180
22
4.1
4.1
99
12
2.2
2.2
470
56
10
10
3 Use average factors (TableII-2-11 for pollutants not listed in this table.
additional calculation is necessary. Horsepower hours can be obtained using the following equation:
w=lph
where: w = Work output (horsepower hour)
I = Load factor (average power produced during operation divided by available power)
p = Available horsepower
h = Hours of usage at load factor (1)
After the work output has been determined, emissions are simply the product of the work output and the
emission i'actor. An approximate load factor for a line-haul locomotive (road service) is 0.4: a typicaJ switch
engine load ['actor is approximately 0 Ofr.1
References for Section II-2
1. Hare. C.T. and K..J. Springer, Exluusi Emissions from Uncontrolled Vehicles and Related Equipment Using
Internal Combustion Engines. Part 1. Locomotive Diesel Engines and Marine Counterparts. Final Report.
Southwest Research Institute. San Antonio, Texas Prepared for the Environmental Protection Agency,
Research Triangle Park. N.C.. under Contract Number EHA 70-108. October 1972.
2. Youna. T.C. Unpublished Data from the Engine Manufacturers Association. Chicago. 111. Mav 1970.
3. Hanley. G.P. Exhaust Emission Information on Electro-Motive Railroad Locomotives and Diesel Engines.
General Motors Corp. Warren, Mich. October 1971.
II- 2-2
EMISSION FACTORS
4/73
-------
II-3 Inboard-Powered Vessels
11-3.1 General - Vessels classified on the basis of use will generally fall into one of three categories: commercial,
pleasure, or military. Although usage and population data on vessels are, as a rule, relatively scarce, information on
commercial and military vessels is more readily available than data on pleasure craft. Information on military
vessels is available in several study reports,1"5 but data on pleasure craft are limited to sales-related facts and
rigures.6-10
Commercial vessel population and usage data have been further subdivided by a number of industrial and
governmental researchers into waterway classifications1'"" (for example, Great Lakes vessels, river vessels, and
coastal vessels). The vessels operating in each of these waterway classes have similar characteristics such as size,
weight, speed, commodities transported, engine design (external or internal combustion), fuel used, and distance
traveled. The wide variation between classes, however, necessitates the separate assessment of each of the, waterway
classes with respect to air pollution.
Information on military vessels is available from both the U.S. Navy and the U.S. Coast Guard as a result of
studies completed recently. The U.S. Navy has released several reports that summarize its air pollution assessment
work.3'5 Emission data have been collected in addition to vessel population and usage information. Extensive
study of the air pollutant emissions from U.S. Coast Guard watercraft has been completed by the U.S. Department
of Transportation. The results of this study are summarized in two reports.1"2 The first report takes an in-depth
look at population/usage of Coast Guard vessels. The second report, dealing with emission test results, forms the
basis for the emission factors presented in this section for Coast Guard vessels as well as for non-military diesel
vessels.
Although a large portion of the pleasure craft in the U.S. are powered by gasoline outboard motors (see section
11-4 of this document), there are numerous larger pleasure craft that use inboard power either with or without
"out-drive" (an outboard-like lower unit). Vessels falling into the inboard pleasure craft category utilize either Otto
cycle (gasoline) or diesel cycle internal combustion engines. Engine horsepower varies appreciably from the small
"auxiliary" engine used in sailboats to the larger diesels used in yachts.
11-3.2 Emissions
Commercial vessels. Commercial vessels may emit air pollutants under two major modes of operation:
underway and at dockside (auxiliary power).
Emissions underway are influenced by a great variety of factors including power source (steam or diesel). engine
size (in kilowatts or horsepower), fuel used (coal, residual oil, or diesel oil), and operating speed and load.
Commercial vessels operating within or near the geographic boundaries ot the L'ni'cJ States fall into one of the
three categories of use discussed above (Great Lakes, rivers, coastline). Tables H-3 i and 1I-'3-2 contain emission
information on commercial vessels falling into these three categories. Table £1-3-3 presents emission factors for
diesel marine engines at various operating modes on the basis of horsepower. Ihese da;a aie applicable to any vessel
having a similar size engine, not just to commercial vessels.
Unless a ship receives auxiliary steam from dockside facilities, goes immediately into drydock, or is out of
operation after arrival in port, she continues her emissions at dockside. Power must be made available for the ship's
lighting, heating, pumps, refrigeration, ventilation, etc. A few steam ships use auxiliary engines (diesel) to supply
power, but they generally operate one or more main boilers under reduced draft and lowered fuel rates-a very
inefficient process. Motorships (ships powered by internal combustion engines) normally use diesel-powered
generators to furnish auxiliary power.17 Emissions from these diesel-powered generators may also be a source of
underway emissions if they are used away from port. Emissions from auxiliary power systems, in terms of the
1/75 Internal Combustion Engine Sources II-3-1
-------
TableII-3-1. AVERAGE EMISSION FACTORS FOR
COMMERCIAL MOTORSHIPS BY WATERWAY
CLASSIFICATION
EMISSION FACTOR RATING: C
Emissions3
Sulfur oxides'3
(SOxasS02)
kg/103 liter
lb/103 gal
Carbon monoxide
kg/103 liter
lb/103 gat
Classc
River
3.2
27
12
100
Great Lakes
3.2
27
13
110
Coastal
3.2
27
13
110
Hydrocarbons
kg/103 liter
lb/103 gal
Nitrogen oxides
(NOX as NO2)
kg/103 liter
lb/103 gal
6.0
50
33
280
'
7.0
59
31
260
6.0
50
32
270
aExpressed as Function of fuel consumed (based on emiision data from
Reference 2 and popu'ation/usage data from References 11 through 16.
^Calculated, not measured. Based on 0.20 percent sulfur content fuel
and density of 0.854 kg/liter (7.12 Ib/gal) from Reference 17.
cVery approximate participate emission factors from Reference 2 are
470 g/hr (1.04 Ib/hr). The reference does not contain sufficient
information to calculate fuel-based factors.
quantity of fuel consumed, are presented in Table II-3-4. In some instances, fuel quantities used may not be
available, so calculation of emissions based on kilowatt hours (kWh ) produced may be necessary. For operating
loads in excess of zero percent, the mass emissions (•;(; in kilograms per hour (pounds per hour) are given by:
e\ = klef (1)
where: k = a constant that relates fuel consumption to kilowatt hours.-
that is. 3.63 x 10'4 1000 liters fuel/kWh
or
9.59 x 10-5 1000 gal fuel/kWh
! = the load. kW
ep = the fuel-specific emission factor from Table 3.2.3-4. kg/10-* liter (lb/10J gal)
II-3-2 EMISSION FACTORS 175
-------
Table! 1-3 2. EMISSION FACTORS FOR COMMERCIAL STEAMSHIPS-ALL GEOGRAPHIC AREAS
EMISSION FACTOR RATING: D
Pollutant
Participates0
Sulfur oxides
[SOX asSO2)e
Carbon monoxidec
Hydrocarbons0
Nitrogen oxides
(NOxasNO2)
Fuel and operating modea
Residual oil'*
Hotel ing
kg/103
liter
1.20d
19.1S
Negd
0.38d
4.37
fb/10'
gal
10.0d
159S
Negd
3.21'
36.4
Cruise
kg/101
liter
2.40
19. IS
0.414
0.082
6.70
lb/103
gal
20.0
159S
3.45
0.682
55.8
Full
kg/103
liter
6.78
19.1S
0.872
0.206
7.63
lb/10J
gal
56.5
159S
7.27
1.72
63.6
Distillate oilb
Hoteling
kg/101
liter
1.8
17. OS
0.5
0.4
2.66
lb/10 J
gal
15
142S
4
3
22.2
Cruise
kg/10J
liter
1.78
17. OS
0.5
0.4
2.83
lb/103
gal
15
142S
4
3
23.6
Full
kg/103
liter
1.78
17.0S
0.5
0.4
5.34
Ib/tO3
gal
15
142S
4
3
44.5
dThe operating modes are based on the percentage of maximum available power: "hoteling" is 10 to 11 percent of available power, "full" is 100 percent of available power, and
"cruise" is an intermediate power (35 to 75 percent, depending on the test organization and vessel tested).
'fust organi/alinns used "Navy Special" fuel oil, winch is not u true residual oil. No vessel test data were available for residual oil combustion. "Residual" oil results are from
References ?, 3, and 5. "Distillate" oil results are from References 3 and 5 only. Exceptions are rioted. "Navy Distillate" was used as distillate test fuel.
^Paniculate, cnibon monoxide, and hydrocarbon emission factors for distillate oil combustion are based on stationary boilers (see Section 1.3 of this document).
Helijrenci! 18 indicates that carbon monoxide emitted during hoteling is small enough to be considered negligible. This reference also places hydrocarbons at 0.38 fcg/fO1 liter (3.2
lb/10' ijiil) and paniculate at 1.20 kg/101 liter (10.0 lb/10' gal). These data are included for completeness only and are not necessarily comparable with other tabulated data.
Emission factors listed are theoretical in that they are based on all the sulfur in the fuel converting to sulfur dioxide. Actual test data from References 3 and 5 confirm the validity of
these theoretical factors. "S" is fuel sulfur content in percent.
1/75
Internal Combustion Engine Sources
II-3-3
-------
TableII-3-3. DIESEL VESSEL EMISSION FACTORS BY OPERATING MODE3
EMISSION FACTOR RATING: C
Horsepower
200
300
500
600
Mode
Idle
Slow
Cruise
Full
Slow
Cruise
Full
Idle
Cruise
Full
Idle
Slow
Cruise
700 Idle
Cruise
900 Idle
2/3
Cruise
1580 Slow
Cru ise
Full
2500
Slow
2/3
Cruise
Full
3600 , Slow
! 2/3
Cruise
: Full
Emissions
Carbon monoxide
lb/103
gal
210.3
145.4
126.3
142.1
59.0
47.3
58.5
282.5
99.7
84.2
171.7
50.8
77.6
293.2
36.0
223.7
62.2
80.9
kg/103
liter
25.2
17.4
15.1
17.0
7.1
5.7
7.0
33.8
11.9
10.1
20.6
6.1
9.3
35.1
4.3
26.8
7.5
9.7
122.4
44.6
237.7
59.8
126.5
78.3
95.9
148.5
28.1
41.4
62.4
14.7
5.3
28.5
7.2
15.2
9.4
11.5
17.8
3.4
5.0
7.5
Hydrocarbons
lb/103
gal
391.2
103.2
170.2
60.0
56.7
51.1
21.0
118.1
44.5
22.8
68.0
16.6
24.1
kg/103
liter
46.9
12.4
20.4
7.2
6.8
6.1
2.5
14.1
5.3
2.7
8.2
2.0
2.9
Nitrogen oxides
-------
TableII-3-4. AVERAGE EMISSION FACTORS FOR DIESEL-POWERED ELECTRICAL
GENERATORS IN VESSELSa
EMISSION FACTOR RATING: C
Rated
output, b
kW
20
40
200
500
Load,c
% rated
output
0
25
50
75
0
25
50
75
0
25
50
75
0
25
50
75
Emissions
Sulfur oxides
(SOxasS02)d
lb/103
gal
27
27
27
27
27
27
27
27
27
27
27
27
27
27
27
27
kg/103
liter
3.2
3.2
3.2
3.2
3.2
3.2
3.2
3.2
3.2
3.2
3.2
3.2
3.2
3.2
3.2
3.2
Carbon
monoxide
lb/10J
gal
150
79.7
53.4
28.5
153
89.0
67.6
64.1
134
97.9
62.3
[ 26.7
58.4
53.4
48.1
43.7
kg/103
liter
18.0
9.55
6.40
3.42
18.3
10.7
8.10
7.68
16.1
11.7
7.47
3.20
7.00
6.40
5.76
5.24
Hydro-
carbons
lb/103
gal
263
204
144
84.7
584
370
285
231
135
33.5
17.8
17.5
209
109
81.9
59.1
kg/103
liter
31.5
24.4
17.3
10.2
70.0
44.3
34.2
27.7
16.2
4.01
2.13
2.10
25.0
13.0
9.8
7,08
Nitrogen oxides
(NOxasN02>
lb/103
gal
434
444
477
495
214
219
226
233
142
141
140
137
153
222
293
364
kg/103
liter
52.0
53.2
57.2
59.3
25.6
26.2
27.1
279
17.0
16.9
16.8
16.4
18.3
26.6
35.1
43.6
Reference 2.
Maximum rated output of the diesel-powered generator.
cGenerator electrical output (tor example, a 20 kW generator at 50 percent load equals 10 kW output).
Calculated, not measured, based on 0.20 percent fuel sulfur content and density of 0.854 kg/hter (7.12 Ib/gal) from Reference 17.
At zero load conditions, mass emission rates (ep may be approximated in terms of kg/hr (Ib/hr) using the
following relationship:
sl = kl rated6 f
where: k = a constant that relates rated output and fuel consumption.
that is. 6.93 x 10'5 1000 liters :uel'k\V
(2)
).83.xlO-5 JOOOgaJfuel/kW
'rated = the rated output. kW
ej- = the fuel-specific emission factor from TableII-3-4. kg' 103 liter (lb/103 gal)
Pleasure craft. Many of the engine designs used in inboard pleasure craft are also used either in military vessels
(diesel) or in highway vehicles (gasoline). Out of a total of 700.000 inboard pleasure craft registered in the United
States in !972. nearly 300.000 were inboard/outdrive. According to sales data. 60 to 70 percent of these
1/75
Internal Combustion Engine Sources
ri-3-5
-------
inboard/outdrive craft used gasoline-powered automotive engines rated at more than 130 horsepower.6 The
remaining 400,000 pleasure craft used conventional inboard drives that were powered bv a variety of powerplants,
both gasoline and diesel. Because emission data are not available for pleasure craft. Coast Guard and automotive
data2'19 are used to characterize emission factors for this class of vessels in Table 11-3-5.
Military vessels. Military vessels are powered by a wide variety of both diesel and suarn power plants. Many of the
emission data used in this section are the result of emission testing programs conducted by the U.S. Navy and the
U.S. Coast Guard.1"3'5 A separate table containing data on military vessels is not provided here, but the included
tables should be sufficient to calculate approximate military vessel emissions.
TABLEII-3.-5. AVERAGE EMISSION FACTORS FOR INBOARD PLEASURE CRAFT3
EMISSION FACTOR RATING. D
Pollutant
Sulfur oxidesd
(SOX as SO2)
Carbon monoxide
Hydrocarbons
Nitrogen oxides
(NOX as NO2)
Based on fuel consumption
Diesel engine'3
kg/10J
liter
3.2
17
22
41
lb/10J
gal
27
Gasoline engine0
kg/10J
liter
0.77
140 149
180
340
10.3
15.7
lb/103
gal
6.4
1240
86
131
Based on operating time
Diesel engine^
kg/hr ! Ib/hr
-
-
-
-
-
Gasoline
kg/hr
0.008
1.69
0.117
0.179
enginec
Ib/hr
0.019
3.73
0.258
0.394
'Average emission factors are based on the duty cycle developed for 'arge outboards (> 48 kilowatts or > 65 horsepower} from Refer-
ence 7. The above factors take into account the impact of water scrubbing of underwater gasoline engine exhaust, also from Reference
7. All values given are for single engine craft and must be modified for multiple engine vessels.
t)Ba««d on tests of diesel engines m Coast Guard vessels, Reference 2.
cBased on tests of automotive engines. Reference 19. Fuel consumption of 11.4 hter^hr '3 ga:>'hr) dssumec. The resulting factors are
only rough estimates.
Based on fuel sulfur content of 0.20 oercent for diesel *jel and 0.043 percent for gasol ne from References 7 and 1 7. Calculated osing
fuel density of 0.740 kg/liter (6.1 7 ib:'gal I for gasoline and 0.854 kg/liter i7.;2 b/gal) tor diesel fuel.
References for Section II-3
1. Walter. R. A.. A. J. Broderick. J. C. Sturm, and E. C. Klaubert. L'SCG Pollution .Abatement Program: A
Preliminary Study of Vessel and Boat Exhaust Emissions. U.S. Department of Transportation. Transportation
Systems Center. Cambridge. Mass. Prepared for the United States Coast Guard. Washington. DC. Repon No.
DOT-TSC-USCG-72-3. November 1971. 119 p.
11-3-6
EMISSION FACTORS
1/75
-------
2. Souza, A. F. A Study of Emissions from Coast Guard Cutters. Final Report. Scott Research Laboratories, Inc.
Plumsteadville, Pa. Prepared for the Department of Transportation. Transportation Systems Center.
Cambridge, Mass., under Contract No. DOT-TSC-429. February 1973.
3. Wallace, B. L. Evaluation of Developed Methodology for Shipboard Steam Generator Systems. Department of
the Navy. Naval Ship Research and Development Center. Materials Department. Annapolis, Md. Report No.
28-463. March 1973. 18 p.
4. Waldron, A. L. Sampling of Emission Products from Ships' Boiler Stacks. Department of the Navy. Naval Ship
Research and Development Center. Annapolis, Md. Report No. 28-169. April 1972. 7 p.
5. Foernsler, R. 0. Naval Ship Systems Air Contamination Control and Environmental Data Base Programs;
Progress Report. Department of the Navy. Naval Ship Research and Development Center. Annapolis, Md.
Report No. 28-443. February 1973. 9 p.
6. The Boating Business 1972. The Boating Industry Magazine. Chicago, 111. 1973.
7. Hare. C. T. and K. J. Springer. Exhaust Emissions from Uncontrolled Vehicles and Related Equipment Using
Internal Combustion Engines. Final Report Part 2. Outboard Motors. Southwest Research Institute. San
Antonio, Tex. Prepared for the Environmental Protection Agency, Research Triangle Park, N.C., under
Contract No. EHS 70-108. January 1973. 57 p.
8. Hurst, J. W. 1974 Chrysler Gasoline Marine Engines. Chrysler Corporation. Detroit, Mich.
9. Mercruiser Sterndrives/ Inboards 73. Mercury Marine, Division of the Brunswick Corporation. Fond du Lac,
Wise. 1972.
10. Boating 1972. Marex. Chicago, Illinois, and the National Association of Engine and Boat Manufacturers.
Greenwich, Conn. 1972. 8 p.
11. Transportation Lines on the Great Lakes System 1970. Transportation Series 3. Corps of Engineers, United
States Army. Waterborne Commerce Statistics Center. New Orleans, La. 1970. 26 p.
12. Transportation Lines on the Mississippi and the Gulf Intracoastal Waterway 1970. Transportation Series 4.
Corps of Engineers, United States Army, Waterborne Commerce Statistics Center. New Orleans, La. 1970. 232
P.
13. Transportation Lines on the Atlantic, Gulf and Pacific Coasts 1970. Transportation Series 5. Corps of
Engineers. United States Army. Waterborne Commerce Statistics Center. New Orleans, La. 1970. 201 p.
14. Schueneman, J. J. Some Aspects of Marine Air Pollution Problems on the Great Lakes. J. Air Pol. Control
Assoc. 74:23-29, September 1964.
15. 197] Inland Waterborne Commerce Statistics. The American Waterways Operations, Inc. Washington, D.C.
October 1972. 38 p.
16. Horsepower on the Inland Waterways. List No. 23. The Waterways Journal. St. Louis, Mo. 1972. 2 p.
17. Hare, C. T. and K. J. Springer. Exhaust Emissions from Uncontrolled Vehicles and Related Equipment Using
Internal Combustion Engines. Part 1. Locomotive Diesel Engines and Marine Counterparts. Southwest
Research Institute. San Antonio, Tex. Prepared for the Environmental Protection Agency. Research Triangle
Park. N.C., under Contract No. EHS 70-108. October 1972. 39 p.
18. Pearson. J. R. Ships as Sources of Emissions. Puget Sound Air Pollution Control Agency. Seattle, Wash.
(Presented at the Annual Meeting of the Pacific Northwest International Section of the Air Pollution Control
Association. Portland. Ore. November 1969.)
19. Study of Emissions from Light-Duty Vehicles in Six Cities. Automotive Environmental Systems, Inc. San
Bernardino. Calif. Prepared for the Environmental Protection Agency. Research Triangle Park. N.C., under
Contract No. 68-04-0042. June 1971.
1/75 Internal Combustion Engine Sources II- 3-7
-------
II- 4 Outboard-Powered Vessels
II-4.1 General - Most of the approximately 7 million outboard motors in use in the United States are 2-stroke
engines with an average available horsepower of about 25. Because of the predominately leisure-time use of
outboard motors, emissions related to their operation occur primarily during nonworking hours, in rural areas,
and during the three summer months. Nearly 40 percent of the outboards are operated in the states of New York,
Texas, Florida, Michigan, California, and Minnesota. This distribution results in the concentration of a large
portion of total nationwide outboard emissions in these states.1
II- 4.2 Emissions - Because the vast majority of outboards hbve underwater exhaust, emission measurement is
very difficult. The values presented in TableII-4-1 are the approximate atmospheric emissions from outboards.
These data are based on tests of four outboard motors ranging from 4 to 65 horsepower.1 The emission results
from these motors are a composite based on the nationwide breakdown of outboards by horsepower. Emission
factors are presented two ways in this section: in terms of fuel use and in terms of work output (horsepower
hour). The selection of the factor used depends on the source inventory data available. Work output factors are
used when the number of outboards in use is available. Fuel-specific emission factors are used when fuel
consumption data are obtainable.
Tablel 1-4-1. AVERAGE EMISSION FACTORS FOR OUTBOARD MOTORS"
EMISSION FACTOR RATING: B
Pollutant13
Sulfur oxidesd
(SOX as SO2)
Carbon monoxide
Hydrocarbons6
Nitrogen oxides
-------
References for sections II-4
1. Hare. C.T. and K.J. Springer. Exhaust Emissions from Uncontrolled Vehicles and Related Equipment Using
Internal Combustion Engines. Part II, Outboard Motors. Final Report. Southwest Research Institute. San
Antonio, Texas. Prepared for the Environmental Protection Agency, Research Triangle Park, N.C.. under
Contract Number EHS 70-108. January 1973.
2. Hare, C.T. and K.J. Springer. Study of Exhaust Emissions from Uncontrolled Vehicles and Related Equipment
Using Internal Combustion Engines. Emission Factors and Impact Estimates for Light-Duty Air-Cooled Utility
Engines and Motorcycles. Southwest Research Institute. San Antonio, Texas. Prepared for the Environmental
Protection Agency, Research Triangle Park, N.C., under Contract Number EHS 70-108. January 1972.
II-4-2 EMISSION FACTORS 4/73
-------
II-5 Small, General Utility Engines
II-5.1 General-This category of engines comprises small 2-stroke and 4-stroke, air-cooled, gasoline-powered
motors. Examples of the uses of these engines are: lawnmowers, small electric generators, compressors, pumps,
minibikes, snowthrowers, and garden tractors. This category does not include motorcycles, outboard motors, chain
saws, and snowmobiles, which are either included in other parts of this chapter or are not included because of the
lack of emission data.
Approximately 89 percent of the more than 44 million engines of this category in service in the United States
are used in lawn and garden applications.1
II-5.2 Emissions-Emissions from these engines are reported in Table II-5-1. For the purpose of emission
estimation, engines in this category have been divided into lawn and garden (2-stroke), lawn and garden (4-stroke),
and miscellaneous (4-stroke). Emission factors are presented in terms of horsepower hours, annual usage, and fuel
consumption.
References for Section II- 5
1. Donohue, J. A., G. C. Hardwick, H. K. Newhall, K. S. Sanvordenker, and N. C. Woelffer. Small Engine Exhaust
Emissions and Air Quality in the United States. (Presented at the Automotive Engineering Congress, Society of
Automotive Engineers, Detroit. January 1972.)
2. Hare. C. T. and K. J. Springer. Study of Exhaust Emissions from Uncontrolled Vehicles and Related
Equipment Using Internal Combustion Engines. Part IV, Small Air-Cooled Spark Ignition Utility Engines.
Final Report. Southwest Research Institute. San Antonio, Tex. Prepared for the Environmental Protection
Agency, Research Triangle Park, N.C., under Contract No. EHS 70-108. May 1973.
1/75 Internal Combustion Engine Sources II-5-1
-------
TableII-5-1. EMISSION FACTORS FOR SMALL, GENERAL UTILITY ENGINES3'6
EMISSION FACTOR RATING: B
Engine
2-Stroke, lawn
and garden
g/hphr
g/metric
hphr
g/gal of
fuel
g/unit-
year
4-Stroke, lawn
Sulfur
ox idesc \
(SOX as S02)
0.54
0.54
1.80
38
and garden
Part icu late
7.1
7.1
23.6
470
Carbon
monoxide
486
486
Hydrocarbons
Exhaust
214
214
1,618 ! 713
33,400
1
g/hphr i 0.37 ; 0.44
g/metric
hphr
0.37 0.44
g/gal of 2.37 [ 2.82
279
279
1,790
14,700
Evaporative0
-
-
-
113
23.2
23.2
149
fuel ;
g/unit- : 26 ! 31 : 19,100
year '<
4-Stroke
1,590 113
miscellaneous \
g/hphr 0.39 0.44 ' 250 j 15.2
g/metric 0.39 : 0.44 250
hphr
g/gal of
3.45 2.77 1,571
fuel
g/unit- ; 30
year
15.2
-
95.5
-
1
34 19,300 1,170 290
i
i i
Nitrogen
oxides
(NOX as NO2)
1.58
1.58
5.26
108
3.17
3.17
20.3
217
4.97
4.97
31.2
384
Alde-
hydes
(HCHO)
2.04
2.04
6.79
140
0.49
0.49
3.14
34
0.47
0.47
2.95
36
•"Reference 2.
Values for g/unit-year were calculated assuming an annual usage of 50 hours and a 40 percent .oact factor. Factors for g/hprr can
be jsed m nstances where jnnual usages, load factors, and rated horsepower are known. Horsepower hours are the product of the
usage in hours, the load factor, and the rated horsepower.
°Values calculated, not measured, based on the use of 0.043 percent sulfur content fuel.
Values calculated from annual f jei consumption. Evaporative losses from storage and filling operations are not included Isee
Chapter 4).
II- 5-2
EMISSION FACTORS
1/75
-------
11-6 Agricultural Equipment
II—6.1 General - Farm equipment can be separated into two major categories: wheeled tractors and other farm
machinery. In 1972, the wheeled tractor population on farms consisted of 4.5 million units with an average power
of approximately 34 kilowatts (45 horsepower). Approximately 30 percent of the total population of these
tractors is powered by diesel engines. The average diesel tractor is more powerful than the average gasoline tractor,
that is, 52 kW (70 hp) versus 27 kW (36 np).1 A considerable amount of population and usage data is available
for farm tractors. For example, the Census of Agriculture reports the number of tractors in use for each county in
the U.S.2 Few data are available on the usage and numbers of non-tractor farm equipment, however. Self-propelled
combines, forage harvesters, irrigation pumps, and auxiliary engines on pull-type combines and balers are examples
of non-tractor agricultural uses of internal combustion engines. Table II-6-1 presents data on this equipment for
the U.S.
II-b.2 Emissions - Emission factors for wheeled tractors and other farm machinery are presented in Table
IL-(.v2. Estimating emissions from the time-based emission factors—grams per hour (g/hr) and pounds per hour
(Ib'hr)-requires an average usage value in hours. An approximate figure of 550 hours per year may be used or. on
r.he basis of power, the relationship, usage in hours = 450 + 5.24 (kW - 37.2) or usage in hours = 450 * 3.89 (hp -
50) may be employed.1
The bes: emissions estimates result from the use of "brake specific" emission factors (g/'kWh or g/hphr).
Emissions are the product of the brake specific emission factor, the usage in hours, the power available, and the
load factor (power used divided by power available). Emissions are also reported in terms of fuel consumed.
TableII-6-1. SERVICE CHARACTERISTICS OF FARM EQUIPMENT
(OTHER THAN TRACTORS)3
Machine
Combine, self-
propelled
Combine, pull
type
Corn pickers
and picker-
shelters
Pick-up balers
Forage
harvesters
Miscellaneous
Units in
service, x103
434
289
687
655
295
1205
Typical
size
4.3m
(14ft)
2.4m
(8ft)
2 -row
5400 kg/hr
(6 ton/hr)
3.7 m
(12 ft) or
3-row
-
Typical power
kW
82
19
_b
30
104
22
hp
110
25
40
140
30
Percent
gasoline
50
100
100
0
50
Percent
diesel
50
0
0
100
50
Reference 1.
Un powered.
1/75
Internal Combustion Engine Sources
II-6-1
-------
TableII-6-2. EMISSION FACTORS FOR WHEELED FARM TRACTORS AND
NON-TRACTOR AGRICULTURAL EQUIPMENT*
EMISSION FACTOR RATING: C
Pollutant
Carbon monoxide
g/hr
Ib/hr
g/kWh
g/hphr
kg/103 liter
lb/103 gal
Exhaust
hydrocarbons
g/hr
Ib/hr
g/kWh
g/hphr
kg/103 liter
lb/103 gal
Crankcase
hydrocarbons'5
g/hr
Ib/hr
g/kWh
g/hphr
kg/103 liter
lb/103 gal
Evaporative
hydrocarbons'3
g/u nit- year
Ib/unit-year
Nitrogen oxides
(NOX asN02)
g/hr
Ib/hr
g/kWh
g/hphr
kg/103 liter
lb/103 gal
Aldehydes
(RCHCasHCHO)
Diesel farm
tractor
161
0.355
4.48
3.34
14.3
119
77.8
0.172
2.28
1.70
7.28
60.7
-
—
-
—
_
—
-
—
452
0.996
12.6
9.39
40.2
335
g/hr ! 16.3
Ib/hr 0.036
g/kWh | 0.456
g/hphr
kg/103 liter
lb/103 gal
Sulfur oxidesc
2)
g/hr
ib/hr
0.340
1.45
Gasoline farm
tractor
3,380
7.46
192
143
391
3,260
128
0.282
7.36
5.49
15.0
125
26.0
0.057
1.47
1.10
3.01
25.1
15,600
34.4
157
0.346
8.88
6.62
18.1
151
7.07
0.016
0.402
0.300
0.821
12.1 j 6.84
42.2
0.093
5.56
0.012
Diesel farm
equipment
(non-tractor)
95.2
0.210
5.47
4.08
16.7
139
38.6
0.085
2.25
1.68
6.85
57.1
-
—
-
—
—
-
-
—
210
0.463
12.11
9.03
36.8
307
7.23
0.016
0.402
0.30
1.22
10.2
21.7
0.048
Gasoline farm
equipment
(non-tractor)
4,360
9.62
292
218
492
4,100
143
0.315
9.63
7.18
16.2
135
28.6
0.063
1.93
1.44
3.25
27.1
1,600
3.53
105
0.231
7.03
5.24
11.8
98.5
4.76
0.010
0.295
0.220
0.497
4.14
6.34
0.014
II-6-2
EMISSION FACTORS
1/75
-------
TabteII-6-2. (continued). EMISSION FACTORS FOR WHEELED FARM TRACTORS AND
NON-TRACTOR AGRICULTURAL EQUIPMENT3
EMISSION FACTOR RATING: C
Pollutant
g/kWh
g/hphr
kg/103 liter
lb/103 gal
Paniculate
g/hr
Ib/hr
g/kWh
g/hphr
kg/103 liter
lb/103 gal
Diesel farm
tractor
1.17
0.874
3.74
31.2
61.8
0.136
1.72
1.28
5.48
45.7
Gasoline farm
tractor
0.312
0.233
0.637
5.31
8.33
0.018
0.471
0.361
0.960
8.00
Diesel farm
equipment
(non-tractor)
1.23
0.916
3.73
31.1
34.9
0.077
2.02
1.51
6.16
51.3
Gasoline farm
equipment
(non- tractor)
0.377
0.281
0.634
5.28
7.94
0.017
0.489
0.365
0.823
6.86
aReferenc8 1.
Crankcase and evaporative emissions from diesel engines are considered negligible.
°Not measured. Calculated from fuel sulfur content of 0.043 percent ana 0.22 percent for gasoline-powered and di»s«l-
povuered equipment, respectively.
References for Section H-6
1. Hare. C. T. and K. J. Springer. Exhaust Emissions from Uncontrolled Vehicles and Related Equipment Using
Internal Combustion Engines. Final Report. Part 5: Heavy-Duty Farm. Construction and Industrial Engines.
Southwest Research Institute. San Antonio, Tex. Prepared for Environmental Protection Agency, Research
Triangle Park. N.C.. under Contract No. EHS 70-108. August 1973. 97 p.
2. County Farm Reports. U.S. Census of Agriculture. U.S. Department of Agriculture. Washington, D.C.
1/75
Internal Combustion Engine Sources
11-6-3
-------
II-7 Heavy-Duty Construction Equipment
I1-7.1 General - The useful life of construction equipment is fairly
short because of the frequent and severe usage it must endure. The
annual usage of the various categories of equipment considered here
ranges from 740 hours (wheeled tractors and rollers) to 2000 hours
(scrapers and off-highway trucks). This high level of use results in
average vehicle lifetimes of only 6 to 16 years. The equipment
categories in this section include: track type tractors, track type
loaders, motor graders, wheel tractor scrapers, off-highway trucks
(includes pavement cold planers and wheel dozers), wheeled loaders,
wheeled tractors, rollers (static and vibratory), and miscellaneous
machines. The latter category contains an array of less numerous mobile
and semi-mobile machines used in construction such as log skidders,
hydraulic excavators/crawlers, trenchers, concrete pavers, compact
loaders, crane lattice booms, cranes, hydraulic excavator wheels, and
bituminous pavers. Some of these categories are different from the Third
Edition.
II-7.2 Emissions - Recently, Environmental Research and Technology, Inc.
prepared a report3 under the sponsorship of a consortium of industry
groups. This report, referred to as the CAL/ERT report, provided a very
comprehensive investigation of farm construction and industrial equipment
emissions. The emissions of twenty different types of construction
equipments are grouped roughly according to the categories in the Third
Edition by their populations in California (based on a report prepared by
the California Air Resources Board4). The updated emission factors on
HC/CO/NO* for heavy-duty construction equipment for diesel engines are
reported in Table II-7.1. No update has been done on other emissions
(aldehydes, sulfur oxides, and particulates), and their values are
carried over from the Third Edition. Less than five percent of the sales
use gasoline engines, and the trend is toward complete dieselization. No
update has been don* on the gasoline engine construction equipment
emissions. Therefore, the emission factors for gasoline engines from
the Third Edition are reprinted in Table II-7.2. The factors are
reported in three different forms-on the basis of running time, fuel
consumed, and power consumed.
In order to estimate emissions from time-based emission factors, annual
equipment usage in hours must be estimated. The following estimates of
use for the equipment listed in the tables should permit reasonable
emission calculations.
II-7-1
-------
Category Annual operation, hours/year
Tracklaying tractors 1050
Tracklaying shovel loaders 1100
Motor graders 830
Scrapers 2000
Off-highway trucks 4000
(including wheeled dozers) 2000
Wheeled loaders 1140
Wheeled tractors 740
Rollers 740
Miscellaneous 1000
The best method for calculating emissions, however, is on the basis of
"brake specific" emission factors (g/kWh or g/hphr). Emissions are
calculated by taking the product of the brake specific emission factor,
the usage in hours, the power available (that is, rated power), and the
load factor (the power actually used divided by the power available).
II-7-2
-------
References for Section II-7
1. Hare, C.T. and K.J. Springer. Exhaust Emissions from Uncontrolled
Vehicles and Related Equipment Using Internal Combustion
Engines-Final Report. Part 5: Heavy-Duty Farm, Construction, and
Industrial Engines. Southwest Research Institute, San Antonio, Tex.
Prepared for Environmental Protection Agency, Research Triangle Park,
H.C., under Contract No. EHS 70-108. October 1973. 105p.
2. Hare, C.T. Letter to C.C. Masser of Environmental Protection Agency,
Research Triangle Park, N.C., concerning fuel-based emission rates
for farm, construction, and industrial engines. San Antonio, Tex.
January 14, 1974. 4p.
3. Ingalls, Melvin N. Recommended Revisions to Gaseous Emission Factors
from Several Classes of Off-Highway Mobile Sources—Final Report.
Southwest Research Institute, San Antonio, Texas. Prepared for
Environmental Protection Agency, Office of Mobile Source Air
Pollution Control, Ann Arbor, MI., under Contract NO. 68-03-3162
September 1984.
4. State of California Air Resources Board. Status Report: Emissions
Inventory on Non-Farm (MS-1), Farm (MS-2), and Lawn and Garden
(Utility) (MS-3) Equipment. July 1983. 87p.
II-7-3
-------
Table II-7.1 Emission Factors for Heavy-Duty, Diesel-Powered
Construction Equipment8
Emission Factor Rating: C
Pollutant
CARBON MONOXIDE
g/hr
Ib/hr
g/kWh
g/hphr
kg/103 liter
lb/103 gal
EXHAUST HYDROCARBONS
g/hr
Ib/hr
g/kWh
g/hphr
kg/103 liter
lb/103 gal
NITROGEN OXIDES
(NOX as NO2)
g/hr
Ib/hr
g/kWh
g/hphr
kg/103 liter
lb/103 gal
ALDEHYDES
(RCHO as HCHO)
g/hr
Ib/hr
g/kWh
g/hphr
kg/103 liter
lb/103 gal
SULFUR OXIDES
(SOx as S02)
g/hr
Ib/hr
g/kWh
g/hphr
kg/103 liter
lb/103 gal
PARTICULATE
g/hr
Ib/hr
g/kWh
g/hphr
kg/10"
Track-type Wheeled Wheeled
tractor tractor dozer"
Motor
Scraper grader
157.01
0.346
2.88
2.15
9.4
78.5
55.06
0.121
1.01
0.75
3.31
27.6
570.70
1.26
10.47
7.81
34.16
284.92
12.4
0.027
0.228
0.170
0.745
6.22
62.3
0.137
1.14
0.851
3.73
31.1
50.7
0. 112
0.928
0.692
3.03
25.3
1622.77
3.59
9.84
7.34
32.19
268.5
85.26
0.188
2.36
1.76
7.74
64.6
575.84
1.269
15.96
11.91
52.35
436.67
13.5
0.030
0.378
0.282
1.23
10.3
40.9
0.090
1.14
0.851
3.73
31.1
61.5
0.136
1.70
1.27
5.57
46.5
568.19
1.257
3.28
2.45
10.16
84.6
128.15
0.282
0.74
0.55
2.28
19.0
1740.74
3.840
10.00
7.46
30.99
258.6
29.5 65.
0.065 0.143
0.215 0.375
0.160 0.280
0.690 1.16
5.76 9.69
158. 210.
0.348 0.463
1.16 1.21
0.867 0.901
3.74 3.74
31.2 31.2
75. 184.
0.165 0.406
0.551 1.06
0.411 0.789
1.77 3.27
14.8 27.3
68.46
0.151
2.06
1.54
6.55
54.65
18.07
0.040
0.48
0.36
1.53
12.73
324.43
0.713
9.57
7.14
30.41
253.84
5.54
0.012
0.162
0.121
0.517
4.31
39.0
0.086
1.17
0.874
3.73
31.1
27.7
0.061
0.838
0.625
2.66
22.2
References 3 and 4 for the HC/CO/NO* emissions, and
references 1 and 2 for other emissions.
The wheeled dozer HC/CO/NCX emissions are included in the
off-highway truck category.
i r - 7 - 4
-------
Table II-7.1 (cont'd) Emission Factors for Heavy-Duty
Diesel-Powered
Construction Equipment0
Emission Factor Rating: C
Off-
Pollutant
CARBON MONOXIDE
g/hr
Ib/hr
g/kWh
g/hphr
kg/103 liter
lb/103 gal
EXHAUST HYDROCARBONS
g/hr
Ib/hr
g/kWh
g/hphr
kg/103 liter
lb/101 gal
NITROGEN OXIDES
(NOX as NO2)
g/hr
Ib/hr
g/kWh
g/hphr
kg/103 liter
lb/103 gal
ALDEHYDES
(RCHO as HCHO)
g/hr
Ib/hr
g/kWh
g/hphr
kg/103 liter
lb/103 gal
SULFUR OXIDES
(SOX as SO2)
g/hr
Ib/hr
g/kWh
g/hphr
kg/103 liter
lb/103 gal
PARTI CULATE
g/hr
Ib/hr
g/kWh
g/hphr
kg/103 liter
lb/103 gal
Wheeled
loader
259.58
0.572
3.63
2.71
11.79
98.66
113.17
0.25
1.59
0.97
5.17
43.16
858.19
1.89
11.81
8.81
38.5
321.23
18.8
0.041
0.264
0.197
0.859
7.17
82.5
0.182
1.15
0.857
3.74
31.2
77.9
0.172
1.08
0.805
3.51
29.3
Tracktype
loader
91.15
0.201
3.03
2.26
9.93
82.85
44.55
0.098
1.49
1.11
4.85
40.55
375.22
0.827
12.46
9.30
40.78
339.82
4.00
0.009
0.134
0.100
0.439
3.66
34.4
0.076
1.14
0.853
3.74
31.2
26.4
0.058
0.878
0.655
2.88
24.0
Highway
truck"
816.81
1.794
4.70
2.28
14.73
123.46
86.84
0.192
0.50
0.37
1.58
13.16
1889.16
4.166
10.92
8.15
34.29
286.10
51.0
0.112
0.295
0.220
0.928
7.74
206.
0.454
1.19
0.887
3.74
31.2
116.
0.256
0.673
0.502
2.12
17.7
Roller
137.97
0.304
8.08
6.03
22.64
188.37
30.58
0.067
1.30
0.97
3.60
30.09
392.90
0.862
17.49
13.05
48.49
404.51
7.43
0.016
0.263
0.196
0.731
6.10
30.5
0.067
1.34
1.00
3.73
31.1
22.7
0.050
1.04
0.778
2.90
24.2
Miscel-
laneous
306.37
0.675
6.16
4.60
18.41
153.51
69.35
0.152
1.35
1.01
4.04
33.70
767.30
1.691
14.75
11.01
44.10
368.01
13.9
0.031
0.272
0.203
0.813
6.78
64.7
0.143
1.25
0.932
3.73
31.1
63.2
0.139
1.21
0.902
3.61
30.1
References 3 and 4 for the HC/CO/NOX emissions and
references 1 and 2 for other emissions.
The off-highway truck category incudes HC/CO/NOX
emissions from the wheeled dozer.
II-7-5
-------
Table II-7.2 Emission Factors for Heavy-Duty, Gasoline-Powered
Construction Equipment8
Emission Factor Rating: C
Pollutant
CARBON MONOXIDE
g/hr
Ib/hr
g/kWh
g/hphr
kg/103
lb/103
EXHAUST HYDROCARBONS
g/hr
Ib/hr
g/kWh
g/hphr
kg/103
lb/103
EVAPORATIVE
HYDROCARBONS"
g/hr
Ib/hr
CRANKCASE
HYDROCARBONS"
g/hr
Ib/hr
NITROGEN OXIDES
(NO* as NO2)
g/hr
Ib/hr
g/kWh
g/hphr
kg/103 liter
lb/103 gal
ALDEHYDES
(RCHO as HCHO)
g/hr
Ib/hr
0.0198
g/kWh
g/hphr
kg/103 liter
lb/103 gal
SULFUR OXIDES
(SOX as S02)
g/hr
Ib/hr
g/kWh
g/hphr
kg/103 liter
lb/10- qal
Wheeled
tractor
4320.
9.52
190.
142.
389.
3250.
164.
0.362
7.16
5.34
14.6
122.
30.9
0.0681
32.6
0.0719
195.
0.430
8.54
6.37
17.5
146.
7.97
0.0176
0.341
0.254
0.697
5.82
7.03
0.0155
0.304
0.227
0.623
5.20
Motor
grader
5490.
12.1
251.
187.
469.
3910.
186.
0.410
8.48
6.32
15.8
132.
30.0
0.0661
37.1
0.0818
145.
0.320
6.57
4.90
12.2
102.
8.80
0.0194
0.386
0.288
0.721
6.02
7.59
0.0167
0.341
0.254
0.636
5.31
Wheeled
loader
7060.
15.6
219.
163.
435.
3630.
241.
0.531
7.46
5.56
14.9
124.
29.7
0.0655
48.2
0.106
235.
0.518
7.27
5.42
14.5
121.
9.65
0.0213
0.298
0.222
0.593
4.95
10.6
0.0234
0.319
0.238
0.636
5.31
Roller
6080.
13.4
271.
202
460.
3840.
277 .
0.611
12.40
9.25
21.1
176.
28.2
0.0622
55.5
0.122
164.
0.362
7.08
5.28
12.0
100.
7.57
0.0167
0.343
0.256
0.582
4.86
8.38
0.0185
0.373
0.278
0.633
5.28
Miscel-
laneous
7720.
17.0
266.
198.
475.
3960.
254.
0.560
8.70
6.49
15.6
130.
25.4
0.0560
50.7
0.112
187.
0.412
6.48
4.79
11.5
95.8
9.00
0.0198
0.298
0.222
0.532
4.44
10.6
0.0234
0.354
0.264
0.633
5.28
II-7-6
-------
Table II-7.2 (cont'd) Emission Factors for Heavy-Duty,
Gasoline-Powered
Construction Equipment8
Emission Factor Rating: C
Wheeled
tractor
10.9
0.0240
0.484
0.361
0.991
8.27
Motor
grader
9.40
0.0207
0.440
0.328
0.822
6.86
Wheeled
loader
13.5
0.0298
0.421
0.314
0.839
7.00
Roller
11.8
0.0260
0.527
0.393
0.895
7.47
Miscel-
laneous
11.7
0.0258
0.406
0.303
0.726
6.06
Pollutant
PARTICULATE
g/hr
Ib/hr
g/kWh
g/hphr
kg/103 liter
lb/103 qal
References 1 and 2.
Evaporative and crankcase hydrocarbons based on operating
time only (Reference 1).
II-7-7
-------
II-8 Snowmobiles
II-8.1 General - In order to develop emission factors for snowmobiles, mass emission rates must be known, and
operating cycles representative of usage in the field must be either known or assumed. Extending the applicability
of data from tests of a few vehicles to the total snowmobile population requires additional information on the
composition of the vehicle population by engine size and type. In addition, data on annual usage and total machine
population are necessary when the effect of this source on national emission levels is estimated.
An accurate determination of the number of snowmobiles in use is quite easily obtained because most states
require registration of the vehicles. The most notable features of these registration data are that almost 1.5 million
sleds are operated in the United States, that more than 70 percent of the snowmobiles are registered in just four
states (Michigan. Minnesota, Wisconsin, and New York), and that only about 12 percent of all snowmobiles are
found in areas outside the northeast and northern midwest.
II-8.2 Emissions - Operating data on snowmobiles are somewhat limited, but enough are available so that an
attempt can be made to construct a representative operating cycle. The required end products of this effort are
time-based weighting factors for the speed/load conditions at which the test engines were operated; use of these
factors will permit computation of "cycle composite" mass emissions, power consumption, fuel consumption, and
specific pollutant emissions.
Emission factors for snowmobiles were obtained through an EPA-contracted study1 in which a variety of
snowmobile engines were tested to obtain exhaust emissions data. These emissions data along with annual usage
data were used by the contractor to estimate emission factors and the nationwide emission impact of this pollutant
source.
To arrive at average emission factors for snowmobiles, a reasonable estimate of average engine size was
necessary. Weighting the size of the engine to the degree to which each engine is assumed to be representative of
the total population of engines in service resulted in an estimated average displacement of 362 cubic centimeters
(cm3).
The speed/load conditions at which the test engines were operated represented, as closely as possible, the
normal operation of snowmobiles in the field. Calculations using the fuel consumption data obtained during the
tests and the previously approximated average displacement of 362 cm-3 resulted in an estimated average fuel
consumption of 0.94 gal/In.
To compute snowmobile emission factors on a gram per unit year basis, it is necessary to know not only the
emission factors but also the annual operating time. Estimates of this usage are discussed in Reference 1. On a
national basis, however, average snowmobile usage can be assumed to be 60 hours per year. Emission factors for
snowmobiles are presented in TableII-b-l.
References for Section II-8
1. Hare. C. T. and K. J. Springer. Study of Exhaust Emissions from Uncontrolled Vehicles and Related
Equipment Using Internal Combustion Engines. Final Report. Part 7: Snowmobiles. Southwest Research
Institute. San Antonio. Tex. Prepared for Environmental Protection Agency. Research Triangle Park. N.C..
under Contract No. EHS 70-108. April 1974.
1/75 Internal Combustion Engine Sources II-8-1
-------
Tabl«II-8-1. EMISSION FACTORS FOR
SNOWMOBILES
EMISSION FACTOR RATING: B
Pollutant
Carbon monoxide
Hydrocarbons
Nitrogen oxides
Sulfur oxides0
Solid particulate
Aldehydes (RCHO)
Emissions
g/u nit-year3
58,700
37,800
600
51
1,670
552
g/galb
1,040.
670.
10.6
0.90
29.7
9.8
g/literb
275.
177.
2.8
0.24
7.85
2.6
9/hrb
978.
630.
10.0
0.85
27.9
9.2
"Based on 60 hours of operation per year and 362 cm displacement.
Bated on 362 cm3 displacement and average fuel consumption of 0.94 gal/hr.
°Based on sulfur content of 0.043 percent by weight.
11-8-2
EMISSION FACTORS
75
"U.S. GOVERNMENT PRINTING OFFICE.1985-6ni-346
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