EPA420-R-98-020

**Commercial Marine Emissions Inventory for EPA Category 2 and 3
Compression Ignition Marine Engines in United States Continental and
Inland Waterways**

21 August 1998

Prepared for:

U.S. Environmental Protection Agency

Office of Mobile Sources

2000 Traverwood

Ann Arbor, MI 48105

Prepared by:

James J. Corbett, Jr., P.E.

Paul S. Fischbeck, Ph.D.

Department of Engineering and Public Policy

Carnegie Mellon University

Pittsburgh, PA 15213

Order No. 8A-0516-NATX

Table of Contents

EXECUTIVE SUMMARY E[2](#executive-summary)

1\. INTRODUCTION [1](#introduction)

2\. ESTIMATION AND METHODOLOGY FOR SHIP EMISSIONS
[1](#estimation-and-methodology-for-ship-emissions)

2.1 Method A: U.S. Emissions Estimated Using Ship Registry Data
[5](#method-a-u.s.-emissions-estimated-using-ship-registry-data)

2.2 Method B: Foreign and Domestic Cargo Transport Fleet Inventory
[9](#method-b-foreign-and-domestic-cargo-transport-fleet-inventory)

2.3 Comparing the U.S. Emissions Inventory with a Global Inventory
[16](#comparing-the-u.s.-emissions-inventory-with-a-global-inventory)

3\. ENGINE TYPES IN EPA CATEGORIES [18](#engine-types-in-epa-categories)

4\. ENGINE REPLACEMENT RATES [19](#engine-replacement-rates)

5\. SUMMARY [21](#summary)

6\. REFERENCES [21](#references)

7\. APPENDICES A[1](#appendices)

7.1 Method A: Ship Operations Method for 1996 (Pages A2-A8)
A[1](#method-a-ship-operations-method-for-1996-pages-a2-a8)

7.2 Method B: Cargo Method using 1993 Cargo Trade Data (Pages A9-A18)
A[1](#method-b-cargo-method-using-1993-cargo-trade-data-pages-a9-a18)

7.3 Engine Manufactures and Engine Models in U.S. Flag Fleet (Pages
A19-A31)
A[1](#engine-manufactures-and-engine-models-in-u.s.-flag-fleet-pages-a19-a31)

# EXECUTIVE SUMMARY {#executive-summary .unnumbered}

The U.S. Environmental Protection Agency (EPA) is currently developing
the first national emission regulations applicable to compression
ignition (CI) marine engines above 37 kilowatts (kW). As part of the
proposed rulemaking, EPA must develop an estimate of the current (i.e.,
baseline) CI marine engine emissions inventory. EPA has defined three
categories for CI marine engines, according to cylinder displacement.
These categories are shown in Table E1.

Table E1. EPA Categories for CI Marine Engines

  ----------------------------------- -----------------------------------
  **EPA Category**                    **Propulsion Engine Displacement
                                      per Cylinder (liters)**

  1                                   Less than 5

  2                                   Equal to 5, less than 20

  3                                   Equal to or greater than 20
  ----------------------------------- -----------------------------------

Calculations for Category 2 and 3 engines are presented in this report.
This report provides estimates of oxides of nitrogen (NOx), particulate
matter (PM), hydrocarbons (HC), and carbon monoxide (CO) from all ships
(domestic and foreign) operating in U.S. navigable waterways (i.e.,
within approximately 200 miles of U.S. coastlines, inland waterways, and
the Great Lakes). Emissions are estimated using ship characteristics
from 1996 fleet registry data *\[LM*IS, 1996\], which include vessels
100 gross registered tons (GRT) and greater. Two analytical methods were
used to estimate the emissions: Method A is based on general ship
operations, and Method B is based on cargo transportation profiles.
Method A estimates emissions for the U.S. flag fleet (excluding those
operating outside U.S. waters) directly from main engine data, and these
emissions are characterized by engine category. Method B estimates
emissions from foreign vessels operating in U.S. waters from information
about foreign cargo transported on foreign vessels into U.S. ports; they
were then characterized by engine category. Method B also estimates
regional emissions for ships involved in trade (not including fishing
vessels, passenger vessels, tugs, and utility ships) using 1996 fleet
registry data, and 1993 data describing waterway transport and trade
*\[USA*CE, 1995\].

Total nationwide emissions equal the sum of emissions from U.S. flag
vessels operating in U.S. waters, and emissions from foreign flag
vessels carrying cargo on U.S. navigable waterways. Total nationwide
emissions from main propulsion CI marine engines on commercial ships
(100 GRT and greater) operating in U.S. waters are shown in Table E2.

**Table E2. Total Nationwide Ship Emissions From Main Engines in U.S.
Waters^a^**

+------------------+--------------+--------------+--------------------+
| 10^3^ Metric     | Engine       | Engine       | Total              |
| tons             | Category 2   | Category 3   |                    |
+------------------+--------------+--------------+--------------------+
| U.S. Flag        | 220.5        | 118.8        | 339.3              |
|                  |              |              |                    |
| NOx              | 4.6          | 9.6          | 14.2               |
|                  |              |              |                    |
| PM               | 9.3          | 3.4          | 12.7               |
|                  |              |              |                    |
| HC               | 28.6         | 10.6         | 39.2               |
|                  |              |              |                    |
| CO               |              |              |                    |
+------------------+--------------+--------------+--------------------+
| Foreign Flag     | 9.9          | 116.9        | 126.9              |
|                  |              |              |                    |
| NOx              | 0.7          | 8.7          | 9.4                |
|                  |              |              |                    |
| PM               | 0.3          | 3.6          | 3.9                |
|                  |              |              |                    |
| HC               | 0.9          | 11.0         | 11.9               |
|                  |              |              |                    |
| CO               |              |              |                    |
+------------------+--------------+--------------+--------------------+
| Grand Total      | 230.4        | 235.7        | 466.1              |
|                  |              |              |                    |
| NOx              | 5.4          | 18.3         | 23.7               |
|                  |              |              |                    |
| PM               | 9.6          | 7.0          | 16.6               |
|                  |              |              |                    |
| HC               | 29.6         | 21.6         | 51.2               |
|                  |              |              |                    |
| CO               |              |              |                    |
+------------------+--------------+--------------+--------------------+

a\. There may be some differences in totals due to rounding.

This report considers emissions only from main propulsion engines, and
does not consider auxiliary engine emissions. For CI marine engines used
in main propulsion, available engine-specific data is provided,
including engine manufacturer and model number.

# INTRODUCTION

The U.S. Environmental Protection Agency (EPA) is currently developing
the first national emission regulations applicable to compression
ignition (CI) marine engines above 37 kilowatts (kW). As part of the
proposed rulemaking, EPA must develop an estimate of the current (i.e.,
baseline) CI marine engine emissions inventory. EPA is considering
dividing CI marine engines into three categories, each with unique
emission regulations. Under the most likely approach to be taken by EPA,
these categories would be defined by engine cylinder displacement, as
shown in Table 1.

Table 1. EPA Categories for CI Marine Engines

  ----------------------------------- -----------------------------------
  **EPA Category**                    **Propulsion Engine Displacement
                                      per Cylinder (liters)**

  1                                   Less than 5

  2                                   Equal to 5, less than 20

  3                                   Equal to or greater than 20
  ----------------------------------- -----------------------------------

Calculations for Category 2 and 3 engines are presented in this report.
This report provides estimates of oxides of nitrogen (NOx), particulate
matter (PM), hydrocarbons (HC), and carbon monoxide (CO) from all ships
(domestic and foreign) operating in U.S. navigable waterways (i.e.,
within approximately 200 miles of U.S. coastlines, inland waterways, and
the Great Lakes). Emissions are estimated for the U.S. flag fleet
directly from main engine data, and these emissions are characterized by
engine category. Emissions from foreign vessels operating in U.S. waters
were estimated from information about foreign cargo transported on
foreign vessels into U.S. ports; they were then characterized by engine
category.

# ESTIMATION AND METHODOLOGY FOR SHIP EMISSIONS

No single approach with currently available data can produce a
comprehensive inventory of ship emissions in U.S. waters.[^1] Therefore,
this analysis developed and applied two different methods to estimate
baseline emissions from commercial CI marine engines from 1996 ship
inventory data *\[LM*IS, 1996\]. Method A produces an inventory of
emissions from commercial U.S. flag vessels with CI marine engines by
considering engine types, duty cycles, and other operational factors.
Method B estimates emissions from foreign and domestic ships
transporting cargo in U.S. waters by estimating the emissions per
ton-mile of cargo moved, and deriving the pollution emitted from cargo
transport in U.S. waters. Since foreign shipping carries significant
volumes of cargo to and from U.S. ports, this method provides an
estimate of emissions from foreign shipping in U.S. waterways;
additionally, regional characteristics of ship emissions are identified
by this method.

By combining the inventory of emissions from U.S. flag vessels (Method
A) with the estimated emissions from foreign cargo ships in Method B, an
estimate of the total nationwide emissions from commercial ships in U.S.
waters results. Method A captures emissions from U.S. flag vessels, and
Method B captures emissions from foreign cargo vessels. This analysis
integrates these distinct estimation methods to develop total nationwide
emissions from CI marine engines used in main propulsion systems for
commercial shipping. Table 2 presents the summary estimate for total
nationwide emissions for EPA Categories 2 and 3.

Table 2. Total Nationwide Emissions from Ship Main Engines in U.S.
Waters^a^

+-------------------+--------------+--------------+--------------------+
| 10^3^ Metric tons | Engine       | Engine       | Total Categories 2 |
|                   | Category 2   | Category 3   | and 3 Engines      |
+-------------------+--------------+--------------+--------------------+
| U.S. Flag         | 220.5        | 118.8        | 339.3              |
|                   |              |              |                    |
| NOx               | 4.6          | 9.6          | 14.2               |
|                   |              |              |                    |
| PM                | 9.3          | 3.4          | 12.7               |
|                   |              |              |                    |
| HC                | 28.6         | 10.6         | 39.2               |
|                   |              |              |                    |
| CO                |              |              |                    |
+-------------------+--------------+--------------+--------------------+
| Foreign Flag      | 9.9          | 116.9        | 126.9              |
|                   |              |              |                    |
| NOx               | 0.7          | 8.7          | 9.4                |
|                   |              |              |                    |
| PM                | 0.3          | 3.6          | 3.9                |
|                   |              |              |                    |
| HC                | 0.9          | 11.0         | 11.9               |
|                   |              |              |                    |
| CO                |              |              |                    |
+-------------------+--------------+--------------+--------------------+
| Grand Total       | 230.4        | 235.7        | 466.1              |
|                   |              |              |                    |
| NOx               | 5.4          | 18.3         | 23.7               |
|                   |              |              |                    |
| PM                | 9.6          | 7.0          | 16.6               |
|                   |              |              |                    |
| HC                | 29.6         | 21.6         | 51.2               |
|                   |              |              |                    |
| CO                |              |              |                    |
+-------------------+--------------+--------------+--------------------+

a\. There may be some differences in totals due to rounding.

Table 3 shows regional detail, derived from Method B, for each pollutant
to be addressed by EPA regulations. Total nationwide Category 2 and 3
emissions reported in Table 2 are simply the sum of the emissions from
U.S. flag CI engines in Method A (e.g., 339.3 thousand metric tons NOx)
and total emissions from foreign CI engines estimated by Method B (e.g.,
126.9 thousand metric tons for NOx). A notable regional insight is that
emissions from Category 2 and 3 CI marine engines on the inland rivers
(e.g., 106.5 thousand metric tons NOx) equal nearly 70% of the combined
emissions from oceangoing (foreign) and coastwise (domestic) shipping
(e.g., 156.3 thousand metric tons NOx). The primary reason for this is
that the ton-miles of cargo moved over inland rivers equal approximately
65% of the ton-miles of cargo transported in U.S. coastal waters.
Moreover, since the navigable miles on the inland rivers equal only
about one third of the navigable ocean miles, emissions from these cargo
movements occur in a much smaller area.

Table 3. Regional Annual Emissions from CI Marine Engines from Cargo
Transport Using Method B (EPA Categories 2 and 3)

+----------------------+-----------+-----------+-----------+-----------+
| **U.S. Region**      | **NOx     | **PM      | **HC      | **CO      |
|                      | Em        | Em        | Em        | Em        |
|                      | issions** | issions** | issions** | issions** |
|                      |           |           |           |           |
|                      | (10^3^    | (10^3^    | (10^3^    | (10^3^    |
|                      | metric    | metric    | metric    | metric    |
|                      | tons      | tons      | tons      | tons      |
|                      | NOx/year) | PM/year)  | HC/year)  | CO/year)  |
+======================+===========+===========+===========+===========+
| Oceangoing (foreign  | 8.0       | 0.4       | 0.2       | 0.7       |
| cargo)               |           |           |           |           |
|                      | 4.9       | 0.1       | 0.15      | 0.5       |
| US Flag CI Engines   |           |           |           |           |
|                      | 3.1       | 0.3       | 0.07      | 0.2       |
| Category 2 CI        |           |           |           |           |
| Engines              | 96.3      | 7.8       | 2.8       | 8.6       |
|                      |           |           |           |           |
| Category 3 CI        | 7.5       | 0.6       | 0.2       | 0.7       |
| Engines              |           |           |           |           |
|                      | 88.8      | 7.2       | 2.6       | 7.9       |
| Foreign CI Engines   |           |           |           |           |
|                      | 104.3     | 8.2       | 3.0       | 9.3       |
| Category 2 CI        |           |           |           |           |
| Engines              |           |           |           |           |
|                      |           |           |           |           |
| Category 3 CI        |           |           |           |           |
| Engines              |           |           |           |           |
|                      |           |           |           |           |
| Total                |           |           |           |           |
+----------------------+-----------+-----------+-----------+-----------+
| Coastwise (domestic  | 52.0      | 2.6       | 1.4       | 4.6       |
| cargo)               |           |           |           |           |
|                      | 31.7      | 0.8       | 1.0       | 3.2       |
| Category 2 CI        |           |           |           |           |
| Engines              | 20.3      | 1.8       | 0.4       | 1.4       |
|                      |           |           |           |           |
| Category 3 CI        |           |           |           |           |
| Engines              |           |           |           |           |
+----------------------+-----------+-----------+-----------+-----------+
| Inland Rivers        | 76.8      | 2.4       | 2.6       | 8.4       |
|                      |           |           |           |           |
| US Flag CI Engines   | 46.8      | 0.7       | 1.8       | 5.8       |
|                      |           |           |           |           |
| Category 2 CI        | 30.0      | 1.7       | 0.8       | 2.6       |
| Engines              |           |           |           |           |
|                      | 29.7      | 1.5       | 1.1       | 3.3       |
| Category 3 CI        |           |           |           |           |
| Engines              | 2.3       | 0.1       | 0.1       | 0.3       |
|                      |           |           |           |           |
| Foreign CI Engines   | 27.4      | 1.4       | 1.0       | 3.0       |
|                      |           |           |           |           |
| Category 2 CI        | 106.5     | 3.9       | 3.6       | 11.6      |
| Engines              |           |           |           |           |
|                      |           |           |           |           |
| Category 3 CI        |           |           |           |           |
| Engines              |           |           |           |           |
|                      |           |           |           |           |
| Total                |           |           |           |           |
+----------------------+-----------+-----------+-----------+-----------+
| Great Lakes          | 9.4       | 0.5       | 0.3       | 0.8       |
|                      |           |           |           |           |
| US Flag Engines      | 5.7       | 0.1       | 0.2       | 0.6       |
|                      |           |           |           |           |
| Category 2 CI        | 3.7       | 0.4       | 0.1       | 0.2       |
| Engines              |           |           |           |           |
|                      | 0.8       | 0.1       | 0.02      | 0.1       |
| Category 3 CI        |           |           |           |           |
| Engines              | 0.06      | 0.005     | 0.002     | 0.005     |
|                      |           |           |           |           |
| Foreign CI Engines   | 0.77      | 0.060     | 0.022     | 0.060     |
|                      |           |           |           |           |
| Category 2 CI        | 10.2      | 0.5       | 0.3       | 0.9       |
| Engines              |           |           |           |           |
|                      |           |           |           |           |
| Category 3 CI        |           |           |           |           |
| Engines              |           |           |           |           |
|                      |           |           |           |           |
| Total                |           |           |           |           |
+----------------------+-----------+-----------+-----------+-----------+
| Total U.S.           | 146.1     | 5.8       | 4.4       | 14,5      |
| Emissions^a,b^       |           |           |           |           |
|                      | 89.0      | 1.7       | 3.1       | 10.0      |
| US Flag Engines      |           |           |           |           |
|                      | 57.1      | 4.1       | 1.3       | 4.4       |
| Category 2 CI        |           |           |           |           |
| Engines              | 126.9     | 9.4       | 3.9       | 11.9      |
|                      |           |           |           |           |
| Category 3 CI        | 9.9       | 0.7       | 0.3       | 0.9       |
| Engines              |           |           |           |           |
|                      | 117.0     | 8.7       | 3.6       | 11.0      |
| Foreign CI Engines   |           |           |           |           |
|                      | **273.0** | **15.2**  | **8.3**   | **26.4**  |
| Category 2 CI        |           |           |           |           |
| Engines              | **99.0**  | **2.4**   | **3.4**   | **11.0**  |
|                      |           |           |           |           |
| Category 3 CI        | **174.0** | **12.8**  | **4.9**   | **15.4**  |
| Engines              |           |           |           |           |
|                      |           |           |           |           |
| **Grand Total for    |           |           |           |           |
| Cargo**              |           |           |           |           |
|                      |           |           |           |           |
| **Category 2 CI      |           |           |           |           |
| Engines**            |           |           |           |           |
|                      |           |           |           |           |
| **Category 3 CI      |           |           |           |           |
| Engines**            |           |           |           |           |
+----------------------+-----------+-----------+-----------+-----------+

a.  There may be some differences in totals due to rounding of numbers.

b.  Emissions estimated to a distance of 200 miles from shore; this is
    approximately the distance from shore as most of the major shipping
    lanes.

These methods rely on a common database of registered ships containing
such information as propulsion type, brake horsepower, and engine data
*\[LM*IS, 1996\]. In addition, both methods used marine diesel emission
factors reported by Lloyd\'s Register Engineering Services in the Marine
Exhaust Emissions Research Programme *\[Carlton et a*l., 1995\]. These
provide the most current emissions factors for large CI marine engines
in commercial use today. These emission factors are similar to currently
available EPA emission factors in AP-42 *\[E*PA, 1997\] for similar CI
engines, as shown in Table 4. (The units of the AP-42 factors (lb/MMBtu
) were converted to match the fuel-based units (kg/tonne fuel) reported
by Lloyds.)

Aside from these two common databases, the estimation methods are quite
different. The methodologies are explained in detail in the next
sections.

Table 4. Comparison of CI Marine Engine Emission Factors with AP-42

+---------------------------------------+------------------------------+
| **Pollutant**                         | **Emission Factor            |
|                                       | (fuel-based)**               |
|                                       |                              |
|                                       | **(kg pollutant/tonne        |
|                                       | fuel)**                      |
+---------------------------------------+------------------------------+
| **Oxides of Nitrogen (NOx) as NO~2~** | 87                           |
|                                       |                              |
| Lloyds: Slow Speed                    | 57                           |
|                                       |                              |
| Lloyds: Medium Speed                  | 53                           |
|                                       |                              |
| AP-42 Emission Factors:               | 73                           |
|                                       |                              |
| Large Stationary Diesel               | 50                           |
|                                       |                              |
| Uncontrolled Diesel Industrial Engine |                              |
|                                       |                              |
| Non-Road CI Engine (steady state)     |                              |
+---------------------------------------+------------------------------+
| **Particulate Matter (PM)**           | 7.6                          |
|                                       |                              |
| Lloyds: Slow Speed                    | 1.2                          |
|                                       |                              |
| Lloyds: Medium Speed                  | 2.0                          |
|                                       |                              |
| AP-42 Emission Factors:               | 5.0                          |
|                                       |                              |
| Large Stationary Diesel               | 1.0                          |
|                                       |                              |
| Uncontrolled Diesel Industrial Engine |                              |
|                                       |                              |
| Non-Road CI Engine (steady state)     |                              |
+---------------------------------------+------------------------------+
| **Hydrocarbons (HC)**                 | 2.4                          |
|                                       |                              |
| Lloyds: All CI Marine Engines         | 1.0                          |
|                                       |                              |
| AP-42 Emission Factors:               | 6.0                          |
|                                       |                              |
| Large Stationary Diesel               | 4.0                          |
|                                       |                              |
| Uncontrolled Diesel Industrial Engine |                              |
|                                       |                              |
| Non-Road CI Engine (steady state)     |                              |
+---------------------------------------+------------------------------+
| **Carbon Monoxide (CO) as CO**        | 7.4                          |
|                                       |                              |
| Lloyds: All CI Marine Engines         | 14.0                         |
|                                       |                              |
| AP-42 Emission Factors:               | 16.0                         |
|                                       |                              |
| Large Stationary Diesel               | 16.0                         |
|                                       |                              |
| Uncontrolled Diesel Industrial Engine |                              |
|                                       |                              |
| Non-Road CI Engine (steady state)     |                              |
+---------------------------------------+------------------------------+

## Method A: U.S. Emissions Estimated Using Ship Registry Data 

Method A (Ship Operations Method) is a theoretical approach using
estimates of daily fuel consumption calculated from ship brake
horsepower (BHP) and engine brake-specific fuel consumption (BSFC).
Fuel-based emission factors were applied to get emissions per day,
making adjustments for usage using marine duty cycles from ISO *\[I*SO,
1996\], estimated time in service, and time underway per year. This
approach allows for a direct estimate of emissions for all types of
vessels, including fishing vessels, tugs, and utility ships.

The numbers of ships in the U.S. commercial fleet with engines in each
category were estimated. This estimate was based on engine manufacturer
and model data gathered for commercial ships greater than 100 gross
registered tons (GRT) and listed in Lloyds Maritime Information System
database of registered vessels *\[LM*IS, 1996\]. Engine data,
particularly cylinder displacement, was available for 42% of the ships
with CI engines in the data set. A statistical test (chi-squared test)
showed that the distribution of unassigned engines was not different
from the distribution of categorized engines.[^2] Based on this
information, the remaining engines were distributed by EPA category
proportionally, as shown in Table 5.

Table 5. Estimated Number of U.S. Flag Ships by Type and EPA Category

  ----------------- -------------- ----------- ---------- ---------- -----------
                    **Category**                                     

  **Vessel          **1**          **2**       **3**      **Not      **Grand
  Service**                                               Diesel**   Total**

  Container         \-             1           49         37         87

  Fishing           2,498          241         40         \-         2,778

  Passenger         8              \-          6          27         41

  RoRo^a^           6              21          39         32         97

  Transport         6              17          49         347        419

  Tug               244            975         42         7          1,269

  Utility           420            171         12         47         650

  **Grand Total**   **3,182**      **1,426**   **236**    **498**    **5,341**
  ----------------- -------------- ----------- ---------- ---------- -----------

a\. RoRo: Roll-on, Roll-off vessel; this includes ships carrying
vehicles and other large, non-containerized items.

This study does not include ships less than 100 GRT, because the Lloyds
database does not contain smaller vessels and it was not possible to
find comparable data for these vessels. One source for smaller vessels
may be the US Coast Guard vessel data collected by the Waterborne
Commerce Statistics Center (WCSC) *\[USA*CE, 1995\]. This data indicates
8,319 U.S. flag vessels (ships and boats) are available for service,
compared to the 5,341 ships in the Lloyds registry; fishing vessels
appear to be excluded from the WCSC data. However, engine data is not
provided for these ships. Another alternate source for information on
smaller vessels may be the Merchant Vessels of the United States CD-ROM
*\[D*OT, 1998\]. This is a data file of merchant and recreational
vessels documented under the laws of the United States by the U.S. Coast
Guard. The file contains the vessel name, official number, managing
owner name, particulars such as tonnage and length, port of
documentation (homeport), and authorized trade endorsements. Once again,
engine-specific data is not provided. This analysis does not use this
source in estimating emissions for this report, although some 63,809
vessels (boats and ships) are listed that may be used in commerce
(171,663 recreational vessels are listed as well). A significant number
may not be powered by CI marine engines at all. Of the remainder, most,
if not all, of these vessels would likely fall into EPA Category 1, and
would not be included in this study.

Brake horsepower for nearly all of these engines is reported in the
Lloyds registry data. The BHP for each engine was multiplied by a
typical brake-specific-fuel-consumption (BSFC) factor for the horsepower
range indicated. Generalized fuel-consumption characteristics for
direct-drive, geared, and diesel-electric CI marine engines illustrate
the relationship between fuel-consumption and engine rating for these
propulsion-plant configurations *\[Harringt*on, 1992\]. These
fuel-consumption characteristics were confirmed by comparison with other
sources *\[Heywo*od, 1988*; Osbour*ne, 1943*; Turpin and McEw*en,
1965\]. Units were converted to tons-fuel per day (tpd). The rated BHP
values used in the fuel-consumption estimates were adjusted downward, in
consideration of the fact that ship engines generally operate at maximum
loads no higher than 80% of rated load. Then marine duty-cycle load
factors were applied, to make the fuel-consumption estimates more
realistic. The E3 duty cycle for heavy-duty marine engines was used
*\[I*SO, 1996*; Markle and Bro*wn, 1996\]. This duty cycle was developed
to represent typical overall engine loads for exhaust emission
measurement; no better duty cycle representing actual operations is
avaible. A summary of the U.S. flag fleet fuel consumption in tpd is
presented in Table 6. These estimates are not unreasonable when compared
with fuel consumption reported by other sources *\[Evans and Marl*ow,
1990*; Ewa*rt, 1982\].

Category 3 engines were divided into two subcategories by cylinder
displacement; engines with cylinder displacements greater than 20 liters
but less than 60 liters were assigned to subcategory 3A. Those greater
than 60 liters were assigned to subcategory 3B. The reason for this is
that emission factors for NOx and PM are different for medium speed and
slow speed engines *\[Carlton et a*l., 1995\] (see Table 4). All
Category 2 engines are assumed to be medium-speed engines. The larger
engines in Category 3 are assumed to be slow-speed engines, but this is
not true of the smaller engine sizes. In the absence of better
information characterizing these engines, this analysis assumed that 50%
of the engines in subcategory 3A were medium-speed engines, and half
were slow-speed engines. Therefore, the fuel-consumption estimates shown
in Table 6 estimate fuel usage for subcategories 3A and 3B separately.
The fuel-based emission factors for CI marine engines were then
multiplied by the estimated fuel-consumption to obtain an estimate for
the daily emissions for each pollutant in kg per day.

Table 6. Estimated Fuel-Consumption for CI Engines in the U.S. Fleet
(tpd)

  ----------------- ----------------- ----------------- -----------------
                    **Category**                        

  **Vessel          **2**             **3A**            **3B**
  Service**                                             

  Container         5                 \-                56

  Fishing           5                 13                10

  Passenger         \-                10                20

  RoRo              6                 48                40

  Transport         6                 31                29

  Tug               5                 24                31

  Utility           4                 20                12
  ----------------- ----------------- ----------------- -----------------

The daily emissions per ship were multiplied by the number of ships, and
by the number of days per year to estimate annual emissions. However,
this estimate represented the unrealistic scenario where vessels were
underway 100% of the time during the year. This study assumed a
conservatively high underway factor of 80% to obtain a final estimate of
annual emissions from U.S. flag ships, based on the authors' knowledge
of and experience with oceangoing ships. An informal telephone survey of
several commercial tug and barge operators (Crowley Maritime
Corporation, Foss Maritime Company, American Commercial Barge Lines
Company, National Marine Inc., and the Port of Pittsburgh) confirmed
that this assumption was also reasonable for tugs and utility vessels.

In estimating total nationwide emissions by Method A, two errors are
present. This inventory only includes U.S. flag vessels, and does not
address foreign vessels operating in and around U.S. waterways. This
also includes U.S. flag vessels operating anywhere in the world. The
problem of including foreign shipping is addressed through Method B,
described in the next section. Analysis of vessels arriving in U.S.
ports carrying foreign cargo *\[USA*CE, 1995\] showed that 410 U.S.
cargo ships (68% of the 597 cargo ships in the U.S. fleet -- nearly all
of which have Category 2 and 3 engines) made approximately 13,500 visits
from foreign ports (15% of the ship visits reported by U.S. Customs).
This represents an average of 33 visits per ship-year (about 1 every 10
days). The problem of removing U.S. flag vessels that are not operating
within U.S. waterways was corrected by assuming that these U.S. flag
vessels spend approximately 30% of their operating time in U.S. waters
(about one day inbound in U.S. waters, one day in harbor, and one day
outbound in U.S. waters). Therefore, estimated emissions were reduced by
approximately 48% (68% - \[68% \* 30%\] = 48%) to "back out" these
emissions occurring outside of U.S. waters. This represents a reasonable
upper bound for the number of U.S. vessels operating outside of U.S.
waters, especially for ships that transport both foreign and domestic
cargoes. Estimates for each pollutant, by type of vessel and by EPA
Category are presented for U.S. flag vessels that operate in U.S. waters
in Table 7.

## Method B: Foreign and Domestic Cargo Transport Fleet Inventory 

Method B (Cargo Method) used cargo movements and waterway data to
calculate the total tons and ton-miles moved by ships annually in and
around the U.S. Then the numbers of "average" cargo ships needed to
carry these volumes were estimated and emissions per ton-mile derived
for these hypothetical cargo ships. The annual emissions estimated by
this approach are directly applicable to U.S. trade regions (for both
foreign and domestic cargo) and national shipping lanes, which include
the Great Lakes, inland waterways, and coastal shipping lanes extending
to approximately 200 miles from the coasts. Most navigable U.S.
waterways are inventoried in the U.S. Army Corps of Engineers (USACE)
Waterway Link Network. Shipping lanes and open water passage lanes are
represented by over 5,000 line segments, or "links." The 1993 National
Waterway Network (NWN) geographic database, developed by the Oak Ridge
National Laboratory, Vanderbilt University, and the National Waterway
GIS Design Committee, includes physical and location information about
each of these links *\[USA*CE, 1995\]. Ocean shipping lanes (waterway
links) in the NWN data were within 200 miles of U.S. coastlines. The
USACE Waterborne Commerce Statistics Center (WCSC) tracks commodity
movements across these links by conducting on-going surveys of companies
and government agencies *\[USA*CE, 1995\]. For this report, 1993 NWN
data on the USACE waterway links were merged with 1993 WCSC shipment
data to create a comprehensive picture of cargo movement in and around
the

Table 7. Estimated Annual Pollution for CI Engines in the U.S. Fleet
(metric tons)

+-----------------+-----------------+-----------------+-----------------+
| **Vessel        | **Category**    |                 | **Categories**  |
| Service**       |                 |                 |                 |
+-----------------+-----------------+-----------------+-----------------+
| **Pollutant**   | **2**           | **3**           | **2 and 3       |
|                 |                 |                 | Total**         |
+-----------------+-----------------+-----------------+-----------------+
| **Container**   | 92              | 36,085          | 36,177          |
|                 |                 |                 |                 |
| NOx (as NOx)    | 2               | 3,152           | 3,154           |
|                 |                 |                 |                 |
| PM              | 4               | 995             | 999             |
|                 |                 |                 |                 |
| HC              | 12              | 3,069           | 3,081           |
|                 |                 |                 |                 |
| CO (as CO)      |                 |                 |                 |
+-----------------+-----------------+-----------------+-----------------+
| **Fishing**     | 37,193          | 9,937           | 47,129          |
|                 |                 |                 |                 |
| NOx (as NOx)    | 783             | 823             | 1,606           |
|                 |                 |                 |                 |
| PM              | 1,566           | 284             | 1,850           |
|                 |                 |                 |                 |
| HC              | 4,828           | 876             | 5,704           |
|                 |                 |                 |                 |
| CO (as CO)      |                 |                 |                 |
+-----------------+-----------------+-----------------+-----------------+
| **Passenger**   | \-              | 2,362           | 2,362           |
|                 |                 |                 |                 |
| NOx (as NOx)    |                 | 196             | 196             |
|                 |                 |                 |                 |
| PM              |                 | 67              | 67              |
|                 |                 |                 |                 |
| HC              |                 | 208             | 208             |
|                 |                 |                 |                 |
| CO (as CO)      |                 |                 |                 |
+-----------------+-----------------+-----------------+-----------------+
| **RoRo**        | 2,255           | 20,912          | 23,167          |
|                 |                 |                 |                 |
| NOx (as NOx)    | 47              | 1,621           | 1,668           |
|                 |                 |                 |                 |
| PM              | 95              | 622             | 717             |
|                 |                 |                 |                 |
| HC              | 293             | 1,918           | 2,211           |
|                 |                 |                 |                 |
| CO (as CO)      |                 |                 |                 |
+-----------------+-----------------+-----------------+-----------------+
| **Transport**   | 1,823           | 18,019          | 19,842          |
|                 |                 |                 |                 |
| NOx (as NOx)    | 38              | 1,442           | 1,480           |
|                 |                 |                 |                 |
| PM              | 77              | 526             | 603             |
|                 |                 |                 |                 |
| HC              | 237             | 1,622           | 1,859           |
|                 |                 |                 |                 |
| CO (as CO)      |                 |                 |                 |
+-----------------+-----------------+-----------------+-----------------+
| **Tug**         | 154,898         | 26,921          | 181,820         |
|                 |                 |                 |                 |
| NOx (as NOx)    | 3,261           | 2,052           | 5,313           |
|                 |                 |                 |                 |
| PM              | 6,522           | 808             | 7,330           |
|                 |                 |                 |                 |
| HC              | 20,110          | 2,492           | 22,602          |
|                 |                 |                 |                 |
| CO (as CO)      |                 |                 |                 |
+-----------------+-----------------+-----------------+-----------------+
| **Utility**     | 24,247          | 4,521           | 28,768          |
|                 |                 |                 |                 |
| NOx (as NOx)    | 510             | 319             | 829             |
|                 |                 |                 |                 |
| PM              | 1,021           | 141             | 1,162           |
|                 |                 |                 |                 |
| HC              | 3,148           | 436             | 3,583           |
|                 |                 |                 |                 |
| CO (as CO)      |                 |                 |                 |
+-----------------+-----------------+-----------------+-----------------+
| **Total**       | 220,507         | 118,759         | 339,266         |
|                 |                 |                 |                 |
| NOx (as NOx)    | 4,642           | 9,604           | 14,247          |
|                 |                 |                 |                 |
| PM              | 9,285           | 3,445           | 12,729          |
|                 |                 |                 |                 |
| HC              | 28,627          | 10,621          | 39,248          |
|                 |                 |                 |                 |
| CO (as CO)      |                 |                 |                 |
+-----------------+-----------------+-----------------+-----------------+

U.S. The cargo movements in ton-miles for each region were then
calculated by summing the product of the number of tons shipped along
each link in a region by the length of that link, as shown below:

Where$C_{G} = \sum_{i = 1}^{5,\text{000}}{L_{\text{Gi}} \ast T_{\text{Gi}}}$

C = Cargo movement in ton-miles

G = Geographic Region (Ocean, Inland, Great Lakes)

L = Length (in miles) of link *i*

T = Tonnage (total tons shipped in 1993) of link *i*

*i* = Each link in the NWN and WCSC data for a given geographic region

A summary of these calculations is shown in Table 8. Interestingly, the
number of tons moved on the inland river systems in the U.S. exceeds the
number moved on the other waterways, including the oceans bordering the
U.S. (by a factor of 2). Alternatively, the distances described by
waterway links for the oceans exceed the distances on the inland rivers
by nearly a factor of 3. The fact that the ton-miles of cargo moved over
inland rivers equal approximately 65% of the ton-miles of cargo
transported in U.S. coastal waters implies that emissions on the inland
waters may be significant. Moreover, since the navigable miles on the
inland rivers equal only about one third of the navigable ocean miles,
emissions from these cargo movements occur in a much smaller area.

Table 8 . Summary of Cargo Movements in 1993 By Major Waterway

  ----------------- ----------------- ----------------- -----------------
  **Region**        **Distance        **10^6^ Tons      **10^9^
                    (miles)^a^**      moved^b^**        Ton-miles**

  Ocean             116,411           15,968.6          764.9

  Great Lakes       8,382             7,662.2           85.3

  Inland Rivers     43,566            33,055.5          494.4

  Unassigned        120               91.9              2.3

  **Total**         168,478           56,778.2          1,346.9
  ----------------- ----------------- ----------------- -----------------

a.  From NWN data *\[USA*CE, 1995\].

b.  From WCSC data *\[USA*CE, 1995\]. Note that tonnage moved is not the
    same as tons received or sent by a given port; the same tons may
    move across several links, and therefore can be counted in the
    ton-miles more than once.

To estimate emissions per ton-mile from commercial marine vessels, the
estimated daily emissions per ship from Method A were used, along with
vessel average deadweight tonnage (DWT) and speed data from Lloyds
registry. Deadweight tonnage is a measurement of total contents of a
ship including cargo, fuel, crew, passengers, food, and water aside from
boiler water. Because DWT describes more than the cargo carrying
capacity of a ship, the DWT reported in Lloyds was multiplied by 80% to
obtain an estimate of the maximum cargo tons that could be carried; this
is consistent with typical voyage estimating factors *\[Packa*rd,
1991\]. Average DWT for cargo vessels (i.e., containers,
roll-on-roll-off ships (RoRo's), and other transport ships (including
dry bulk, tankers, etc.) was computed for all vessels in Lloyds registry
(including U.S. flag) and separately for U.S. flag vessels. The average
DWT for cargo ships in the world fleet is 34,387 DWT; the average DWT
for cargo ships in the U.S. flag fleet is 15,454 DWT.

However, ships do not typically operate fully loaded with cargo. Many
ships, particularly tankers, may carry cargo in one direction and return
empty (or with ballast only). Other ships carry cargo both directions,
but rarely carry their full capacity. Most ships carry cargo loads that
average 50% to 65% capacity; when cargo capacities exceed 70%, it can be
indication that too few ships are available for the route *\[Abra*ms,
1997\]. This analysis applied a cargo capacity factor of 50% to vessels
operating on ocean routes, and a 60% cargo capacity factor to inland
rivers and Great Lakes vessels. This is consistent with reported
statistics *\[Wilde Mathe*ws, 1998a\]. The higher capacity factor for
inland river cargo transport follows from the understanding that inland
vessels are smaller, with shallower drafts and smaller total capacities
per vessel. This fact, combined with the large tonnages moved on inland
rivers, implies that these vessels are loaded to higher capacities than
oceangoing and coastwise transport. Moreover, barges can be added or
removed from a group of as many as 35 barges *\[Wilde Mathe*ws, 1998b\],
and therefore barge towboats/pushboats may also transport higher average
capacities.

Speed data reported in Lloyds represents the rated design speed of the
vessel, similar to the BHP data. Therefore, marine duty-cycle load
factors were applied to speed, in the same way as for BHP in Section
2.1. The E3 duty cycle was used for heavy-duty marine engines for all
engines *\[I*SO, 1996*; Markle and Bro*wn, 1996\]. To be consistent with
adjustments made to the maximum BHP load to be 80% of rated BHP, the
maximum speed was adjusted by employing the relationship between
horsepower and the cube of the speed *\[Lauren*ce, 1984\]. This resulted
in a maximum speed that is 93% of the rated design speed of the vessel.
Average speeds for cargo ships in the U.S. flag fleet are shown in Table
9. Average speeds for the world fleet are presented in Table 10.

From this information, the emissions per ton-mile and emissions per year
can be calculated, according to the following equations:

$E_{\text{TM}} = E_{d} \div \left( \text{DWT} \ast \text{CCF} \ast V \ast \text{24} \right)$

Where

E~TM~ = Emissions per ton-mile

E~d~ = Emissions per day (from Method A)

DWT = Average DWT per ship

CCF = Cargo capacity factor

> (0.5 for oceans, 0.6 for inland rivers and Great Lakes)

V = Average speed of vessel across duty cycle (adjusted for max BHP)

24 = Hours per day to convert ship speed to ship miles per day

$E_{Y} = E_{\text{TM}} \ast \text{TM}_{Y}$

Where

E~Y~ = Emissions per year

TM~Y~ = Ton-miles per year (from Table 8)

Table 9. Average Speed (in knots) of U.S. Fleet Cargo Ships (adjusted
for duty cycle)^a^

  ---------------- -------------- --------- --------- --------- --------- --------------
                   **Category**                                           **Weighted**

  **Vessel                        **1**     **2**     **3A**    **3B**    **Average**
  Service**                                                               

  **Container**                   \-        5         \-        10        10

  **RoRo**                        6         8         10        10        9

  **Transport**                   5         7         8         8         7

  **Weighted                      5         7         9         9         9
  Average**                                                               
  ---------------- -------------- --------- --------- --------- --------- --------------

a\. The average speed of tugs moving barges on inland waters equals 79%
of the speed of U.S. cargo vessels; this is taken as the average speed
on the inland rivers.

Table 10. Average Speed (in knots) of World Fleet Cargo Ships (adjusted
for duty cycle)

  ---------------- -------------- --------- --------- --------- --------- --------------
                   **Category**                                           **Weighted**

  **Vessel                        **1**     **2**     **3A**    **3B**    **Average**
  Service**                                                               

  **Container**                   \-        6         13        16        16

  **RoRo**                        6         8         14        14        12

  **Transport**                   5         6         12        12        11

  **Weighted                      5         6         12        12        11
  Average**                                                               
  ---------------- -------------- --------- --------- --------- --------- --------------

To distinguish between domestic and foreign trade, port data indicating
the amount of domestic and foreign cargo was taken from the WCSC data on
the US Waterways CD-ROM *\[USA*CE, 1995\]. Here, the cargo tons
delivered or shipped from the 179 ports reported in the data was used,
rather than the tons moved along the waterway links. In 1993, 49% of the
cargo delivered to ports in U.S. ocean regions (Atlantic, Pacific, and
Gulf Coasts) was domestic. In Great Lakes, 80% of the trade was
domestic; 70% of trade shipped on the inland rivers was domestic.

To estimate the number of U.S. ships engaged in foreign trade, this
analysis used U.S. Census Bureau data indicating the number of port
visits for foreign commerce (i.e., that involved U.S. Customs) in 1993
*\[USA*CE, 1995\]. Some 90,000 ship visits nationwide were reported.
Approximately 15% of these vessels making port visits were registered as
U.S. flag ships; this factor was applied to separate foreign trade into
foreign trade carried by U.S. ships and foreign trade carried by foreign
ships. (While 15% of the vessels making visits with foreign cargo were
U.S. flag vessels, this amounted to 68% of the cargo ships in U.S.
registered fleet as discussed in Section 2.1.)

This emission estimate assumes CI marine engines propel all vessels.
This assumption is generally valid for non-U.S.-flag cargo vessels
(which are nearly all diesel-propelled), but it is not true for U.S.
flag cargo ships. While ships with steam-turbine engines only account
for 6% of the U.S. flag fleet, they equal 52% of the U.S. flag
cargo-carrying vessels. Marine steam-turbine engines emit significantly
less NOx, HC, and CO, and about the same PM as CI marine engines *\[Booz
Allen & Hamilt*on, 1991\]. This analysis corrected the raw calculations
to account for U.S. steam ships. This was done by taking 52% of the raw
estimate and multiplying it by the ratio of steam-engine-emission factor
to diesel-engine-emission factor for each pollutant.

Lastly, these emissions were characterized by engine category. World
fleet characteristics for cargo vessels were assumed to apply to foreign
flag vessels transporting cargo in U.S. waters. Emissions estimated for
foreign ships by Method B were distributed according to the percent of
foreign cargo vessels with engines in EPA Categories 1, 2 and 3.
Estimates for emissions from cargo transport are shown by region,
domestic versus foreign, in Table 11. Steam engines are shown separately
from diesel engines, and diesel engines in Categories 2 and 3 are shown
as a subset of diesel engines.

Table 11. Emissions from Maritime Transport of Cargo in U.S. Waterways
^a^

+----------------------+-----------+-----------+-----------+-----------+
| **U.S. Region**      | **NOx**   | **PM**    | **HC**    | **CO**    |
|                      |           |           |           |           |
|                      | (metric   | (metric   | (metric   | (metric   |
|                      | tons      | tons      | tons      | tons      |
|                      | NOx/year) | PM/year)  | HC/year)  | CO/year)  |
+======================+===========+===========+===========+===========+
| Oceangoing (foreign  | **9,836** | **801**   | **284**   | **876**   |
| cargo)               |           |           |           |           |
|                      | 8,695     | 414       | 238       | 775       |
| **US Ship Engines**  |           |           |           |           |
|                      | 7,993     | 397       | 217       | 705       |
| All US CI Engines    |           |           |           |           |
|                      | 1,141     | 387       | 46        | 101       |
| US Cat. 2 and 3      |           |           |           |           |
|                      | **        | **8,448** | **2,999** | **9,248** |
| US Steam/other       | 103,803** |           |           |           |
|                      |           | 7,840     | 2,783     | 8,581     |
| **Foreign Ship       | 96,325    |           |           |           |
| Engines**            |           | **9,249** | **3,283** | *         |
|                      | **        |           |           | *10,124** |
| Foreign Cat. 2 and 3 | 113,639** | 8,237     | 3,000     |           |
|                      |           |           |           | 9,286     |
| **Oceangoing Total** | 104,318   |           |           |           |
|                      |           |           |           |           |
| All Cat. 2 and 3     |           |           |           |           |
+----------------------+-----------+-----------+-----------+-----------+
| Coastwise (domestic  | 56,535    | 2,690     | 1,550     | 5,041     |
| cargo)               |           |           |           |           |
|                      | 51,971    | 2,582     | 1,409     | 4,583     |
| All US CI Engines    |           |           |           |           |
|                      | 7,417     | 2,515     | 298       | 656       |
| US Cat. 2 and 3      |           |           |           |           |
|                      | *         | **5,205** | **1,848** | **5,697** |
| US Steam/other       | *63,952** |           |           |           |
|                      |           |           |           |           |
| **Coastwise Total**  |           |           |           |           |
+----------------------+-----------+-----------+-----------+-----------+
| Inland Rivers        | *         | **4,777** | **3,368** | *         |
|                      | *94,499** |           |           | *10,386** |
| **US Ship Engines**  |           | 2,468     | 2,826     |           |
|                      | 83,539    |           |           | 9,190     |
| All US CI Engines    |           | 2,370     | 2,569     |           |
|                      | 76,795    |           |           | 8,354     |
| US Cat. 2 and 3      |           | 2,308     | 543       |           |
|                      | 10,960    |           |           | 1,196     |
| US Steam/other       |           | **1,619** | **1,141** |           |
|                      | *         |           |           | **3,519** |
| **Foreign Ship       | *32,020** | 1,502     | 1,059     |           |
| Engines**            |           |           |           | 3,266     |
|                      | 29,713    | **6,395** | **4,510** |           |
| Foreign Cat. 2 and 3 |           |           |           | *         |
| **Inland Rivers      | **        | 3,872     | 3,628     | *13,906** |
| Total**              | 126,518** |           |           |           |
|                      |           |           |           | 11,620    |
| All Cat. 2 and 3     | 106,508   |           |           |           |
+----------------------+-----------+-----------+-----------+-----------+
| Great Lakes          | *         | **940**   | **334**   | **1,029** |
|                      | *11,556** |           |           |           |
| **US Ship Engines**  |           | 486       | 280       | 911       |
|                      | 10,216    |           |           |           |
| All US CI Engines    |           | 467       | 255       | 828       |
|                      | 9,391     |           |           |           |
| US Cat. 2 and 3      |           | 454       | 54        | 119       |
|                      | 1,340     |           |           |           |
| US Steam/other       |           | **73**    | **26**    | **80**    |
|                      | **901**   |           |           |           |
| **Foreign Ship       |           | 68        | 24        | 74        |
| Engines**            | 836       |           |           |           |
|                      |           | **1,014** | **360**   | **1,110** |
| Foreign Cat. 2 and 3 | *         |           |           |           |
| **Great Lakes        | *12,457** | 535       | 279       | 903       |
| Total**              |           |           |           |           |
|                      | 10,227    |           |           |           |
| All Cat. 2 and 3     |           |           |           |           |
+----------------------+-----------+-----------+-----------+-----------+
| Total U.S.           | **        | *         | **5,834** | *         |
| Emissions^a,b^       | 179,842** | *11,723** |           | *17,989** |
|                      |           |           | 4,895     |           |
| **US Ship Engines**  | 158,984   | 6,058     |           | 15,917    |
|                      |           |           | 4,405     |           |
| All US CI Engines    | 146,151   | 5,816     |           | 14,470    |
|                      |           |           | 940       |           |
| US Cat. 2 and 3      | 20,858    | 5,665     |           | 2,072     |
|                      |           |           | **4,167** |           |
| US Steam/other       | **        | *         |           | *         |
|                      | 136,723** | *10,140** | 3,866     | *12,847** |
| **Foreign Ship       |           |           |           |           |
| Engines**            | 126,874   | 9,410     | *         | 11,922    |
|                      |           |           | *10,001** |           |
| Foreign Cat. 2 and   | **        | *         |           | *         |
| 3^a^ **Grand Total   | 316,566** | *21,863** | 8,316     | *30,836** |
| (All Ships)**        |           |           |           |           |
|                      | 273,025   | 15,226    |           | 26,392    |
| All Cat. 2 and 3     |           |           |           |           |
+----------------------+-----------+-----------+-----------+-----------+

a.  Foreign ship Category 2 and 3 numbers appear in Tables E2 and Table
    2 as the estimates of total foreign flag emissions in U.S. waters.

b.  There may be some differences in totals due to rounding of numbers.

c.  Emissions estimated to a distance of 200 miles from shore; this is
    approximately the distance from shore as most of the major shipping
    lanes.

By assuming that all foreign flag vessels operating in U.S. waters are
cargo vessels, the emissions estimated for foreign flag cargo vessels
can be added to the emissions estimated for U.S. flag vessels
(calculated in Section 2.1) to provide a single nationwide estimate for
emissions from commercial shipping. This relies on the understanding
that fishing vessels, tugs, utility vessels, and most passenger/ferry
vessels operating in U.S. waters are U.S. flag vessels. The possible
exception to this understanding would be foreign passenger cruise ships.
Emissions from these relatively few ships are not expected to change the
nationwide inventory of ship emissions.[^3] In fact, emissions from
these ships may only impact port emissions inventories that are
dominated by tourism-related vessel activity.

## Comparing the U.S. Emissions Inventory with a Global Inventory

Previous work can be used to verify that the estimate of nationwide
emissions from ships in U.S. waters provide is reasonable. A global
inventory of ship emissions that was developed independent of the
analysis for this report *\[Corbett and Fischbe*ck, 1997\] can provide a
point of comparison. Because this method derives the traffic densities
for ships from the Comprehensive Ocean-Atmosphere Data Set (COADS), this
approach estimates only the coastal emissions (both oceangoing and some
coastwise domestic); it cannot reliably estimate emissions on the Great
Lakes, or the inland waterway emissions. In addition, this method was
not intended to include detailed coastwise domestic operations very near
the coastlines. Also, the COADS data filtered out reports from large
fishing fleets. Therefore, this provides only a rough check of the sum
of oceangoing and coastwise emissions estimated by Method B.

Global
$P = \sum_{i = 1}^{n}{E_{i} \ast \left( F \ast A_{i} \right)}$emissions
calculations used the following equation to obtain the total emissions
from international shipping:

> Where:
>
> P = Total propulsion emissions.
>
> E~I~ = Fuel-based pollutant emission factor based on engine type.
>
> F = Annual marine fuel (bunkers) used.
>
> A~i~ = Percent of all vessels with each engine type.
>
> i = Engine type (1 = slow-speed, 2 = medium-speed, and 3 =
> steam/other.
>
> n = 3 engine types for NOx calculation.

Emission rates from Lloyd's were applied to diesel engines (see Table
4). A steam-turbine emission rate of 8.8 kg NOx/tonne fuel was derived
from data in a 1991 study by TRC Environmental Consultants, Inc.
*\[Hottenste*in, 1991\]. Since more than 95% of ships in the world fleet
use CI marine engines and the emission rates are higher for CI engines
than for boilers, the resulting estimates reasonably represent CI
emission estimates for practical purposes. The annual estimates for
global NOx emissions were calculated by weighting the yearly marine-fuel
use by the actual percent of marine engines of each type (slow-speed
diesel, medium-speed diesel, and steam turbine). The average estimate
for annual NOx emissions is simply the average of the estimates for each
year: 10.12 million metric tons of NOx/yr. Global emissions (average
estimates) were divided by the total annual COADS ship observations to
get the average emissions per observation. This value was then
multiplied by the number of observations in each 2^o^ x 2^o^ grid
location to map the distribution of global marine emissions. (More
discussion of this method is available *\[Corbett and Fischbe*ck, 1997*;
Corbett et a*l., 1998\].)

U.S. coastal emissions are simply the sum of the emissions estimated in
each grid cell adjoining the coasts in the Atlantic, Pacific, and Gulf
regions. Table 12 illustrates this approach for NOx emissions, including
approximate distances from the U.S. coastlines in kilometers and miles.
Shipping links described in Method B generally correspond to a distance
between 1 and 1½ grid cells of the U.S. coastline. Table 13 shows all
pollutants considered. If 1½ grid cells are used, these estimates are
within 13% to 25% of the overall coastal emissions (the sum of
oceangoing and coastwise emissions for all engine types) from cargo
ships in U.S. waters presented in Table 11.

Table 12. Summary of NOx Emissions Near U.S. Coastlines From Previous
Work

  ---------------- --------------- --------------- --------------- -------------
  **Number of      **NOx Emissions **Approximate   **Approximate   **Emissions
  Cells from U.S.  (10^3^ tons     Distance (km)** Distance (mi)** as a % of
  Coasts**         NOx/yr)**                                       Global**

  3 Grid Cells     516.2           667             414             5%

  2 Grid Cells     319.0           444             276             3%

  1½ Grid Cells    203.9           333             207             2%

  1 Grid Cell      88.7            222             138             1%
  ---------------- --------------- --------------- --------------- -------------

Table 13. Emissions Within Approximately 200 Miles of U.S. Coastline

  ---------------------- ------------ ------------ ------------ ------------
                         10^3^ kg     10^3^ kg     10^3^ kg     10^3^ kg
                         NOx/yr       PM/yr        HC/yr        CO/yr

  Oceangoing/Coastwise   203.9        17.2         6.9          21.2
  ---------------------- ------------ ------------ ------------ ------------

# ENGINE TYPES IN EPA CATEGORIES

Engine manufacturer and model data were available for some of the U.S.
flag vessels in the Lloyds register data *\[LM*IS, 1996\]. Appendix 7.3
presents this data by vessel type and EPA Category. Ships with engines
in EPA Category 2 are listed in Table 16. Those with engines in EPA
Category 3 (shown as Category 3A, corresponding to cylinder
displacements equal to 20 liters and less than 60 liters, and as
Category 3B, corresponding to cylinder displacements equal to and
greater than 60 liters) in Table 17. It should be noted that these
tables show the number of vessels with each engine type; the number of
engines per vessel was not reported in the data available. No other
engine-specific data is provided in the Lloyds data fields that we use
in our research, although Lloyds Registry may have that information.
Engine-specific information, such as bore, stroke, rpm, etc., was
obtained from manufacturer sources such as websites, and telephone
conversations with manufacturer representatives. Some engine
manufacturers were not located, perhaps because the engines are foreign,
or no longer manufactured; in some cases engine manufacturers have
consolidated or split into separate corporations. Engines that were not
categorized are presented in Table 18. This analysis focused on defining
cylinder displacement so that engines could be classified by EPA
Category. Other data (e.g., turbocharging, aftercooling, etc.) were not
consistently available and are not reported.

# ENGINE REPLACEMENT RATES

Important considerations in developing regulations for CI marine engines
include how quickly ships and/or their engines are replaced, and how
fast the fleet may be growing. If emissions regulations apply primarily
to new engines, then the impact on actual emissions depends on the rate
at which emission controls are introduced through engine replacements.
Engine replacement is a function of two primary factors: 1) The number
of ships retired from service and scrapped; and 2) The number of new
vessels built and placed in service. (A secondary factor in estimating
engine replacement rates is replacement of engines on existing vessels
without scrapping the ship itself. As of now, we have no direct
information on engine replacement rates of this sort.) In recent years,
approximately 1% of the world fleet greater than 1,000 GRT was
demolished (broken-up) annually while new ships in this group accounted
for approximately 3% of the world fleet *\[UNCT*AD, 1995\]; therefore
the net growth of the world fleet is currently about 2% per year.

Moreover, the U.S. fleet has not been building at the same rate as the
world fleet (see Figure 1). The U.S. flag fleet has lagged the pace of
the world fleet in both of these aspects during the last decade, at
least. From data shown in Figure 1, it can be seen that the U.S. fleet
construction rate has been less than 15 ships per year since 1983,
whereas world fleet construction has averaged about 1,500 ships per
year. In other words, U.S. fleet construction has equaled \~0.5% of the
approximately 5,300 ships in the U.S. fleet compared to world fleet
construction of \~2% of the approximately 86,000 ships in the world
fleet.

The world-fleet average age of a vessel when demolished is shown for
recent years in Table 14 *\[UNCT*AD, 1995\]. The average age of the U.S.
Fleet, by vessel type, is shown in Table 15; it is clear that the U.S.
fleet is significantly older than the world average. It is reasonable to
believe the U.S. flag fleet may increase its rate of fleet replacement
in coming years, to stay competitive with the world fleet vessel
construction. However, there is insufficient evidence to expect the U.S.
fleet replacement rate to exceed the world fleet replacement rate of
approximately 2% per year. Under current market and policy conditions
(e.g., U.S. versus foreign labor rates for merchant vessel crews, and
the Jones Act), there are limited economic incentives to modernize the
U.S. flag fleet at the world fleet replacement rate. Therefore, the 2%
per year world fleet replacement rate assumption would imply at most the
construction of 1,000 additional ships of 100 GRT or greater over a
ten-year period (2000-2010). However, only 503 ships have been built in
the U.S. during the twenty-two year period of 1975 to 1996 (see Figure
1). Therefore, a more realistic upper bound might be 250 ships (100 GRT
or greater) built over a ten-year period (2000-2010).

![](media/image1.wmf)Figure 1. Comparison of New Shipbuilding in U.S.
Flag and World Fleets *\[Lloyd\'s_Regist*er, 1970-1994*; MAR*AD, 1996\]

Table 14. Average Age of Broken-up Ships Greater Than 1,000 GRT by
Vessel Type During 1986-1994

  -------------- -------------- -------------- ---------------- --------------
  **Year**       **Tankers**    **Dry Bulk**   **Containers**   **General
                                                                Cargo**

  1986           21.3           19.4           21.7             23.6

  1987           24.4           19.8           24.9             23.8

  1988           24.6           22.4           25.1             24.2

  1989           24.9           23.1           27.2             25.5

  1990           26.4           21.7           19.5             25.1

  1991           25.3           22.0           19.0             24.8

  1992           25.8           22.9           19.1             25.7

  1993           24.7           24.0           22.9             26.4

  1994           24.6           24.1           24.0             27.1
  -------------- -------------- -------------- ---------------- --------------

Table 15. Average Year Built for the 1996 U.S. Fleet Greater Than 100
GRT *\[LM*IS, 1996\]

  ----------------------- ----------------------- -----------------------
  **Vessel Service**      **Average Year Built**  **Average Age in 1996**

  Container               1978                    18

  Fishing                 1975                    21

  Passenger               1959                    37

  RoRo                    1974                    22

  Transport               1964                    32

  Tug                     1969                    27

  Utility                 1976                    20

  U.S. Fleet Average      1973                    23
  ----------------------- ----------------------- -----------------------

# SUMMARY

A commercial marine emissions inventory was developed that estimates the
emissions of NOx, PM, HC, and CO from U.S. flag and foreign flag vessels
operating in U.S. waters. This inventory is characterized by vessel
service type and by EPA Category (representing engine cylinder
displacement). Emissions from commercial vessels that carry cargo were
estimated by region, including oceangoing (international), coastwise
(domestic), inland river system, and Great Lakes. Emissions from cargo
transport on the U.S. inland rivers equals nearly 70% of the total
emissions from oceangoing and coastwise cargo transportation on all
three coastlines. Oceangoing and coastal emissions estimated for cargo
ships were compared with emission derived from previous work estimating
global shipping emissions. Auxiliary engine emissions were not
considered in this analysis. Engine-specific data available from the
Lloyds dataset is provided, including engine manufacturer and model
number. The U.S. fleet replacement rate is lower than the rate of
replacement in the world fleet, and is not expected to increase
construction beyond the world fleet replacement rate of approximately 2%
per year under current market and policy conditions.

# REFERENCES

Abrams, A., Ship Cargo Capacity Tightens in 2nd Quarter, in *Journal of
Commerce*, Washington, DC, 1997.

Booz Allen & Hamilton, Commercial Marine Vessel Contributions to
Emission Inventories: Draft Final Report, Booz, Allen & Hamilton, Inc.,
Los Angeles, CA, 1991.

Carlton, J.S., S.D. Danton, R.W. Gawen, K.A. Lavender, N.M. Mathieson,
A.G. Newell, G.L. Reynolds, A.D. Webster, C.M.R. Wills, and A.A. Wright,
Marine Exhaust Emissions Research Programme, Lloyd\'s Register
Engineering Services, London, 1995.

Corbett, J.J., and P.S. Fischbeck, Emissions From Ships, *Science*,
*278* (5339), 823-824, 1997.

Corbett, J.J., P.S. Fischbeck, and S.N. Pandis, Global Nitrogen and
Sulfur Emissions Inventories for Oceangoing Ships, *Journal of
Geophysical Research*, *under review*, 1998.

DOT, Merchant Vessels of the United States (Raw data only) (on CD-ROM),
NTIS, National Technical Information Service, Washington, DC, 1998.

EPA, *AP-42: Compilation of Air Pollutant Emission Factors*, U.S.
Environmental Protection Agency, Research Triangle Park, NC, 1997.

Evans, J.J., and P.B. Marlow, *Quantitative Methods in Maritime
Economics*, 282 pp., Fairplay Publications Ltd., Coulsdon, Surrey, UK,
1990.

Ewart, W.D., *Bunkers*, 72 pp., Fairplay Publications Ltd., Surrey CR3
2HR, UK, 1982.

Harrington, R.L., Marine Engineering, pp. 953, Society of Naval
Architects and Marine Engineers, Jersey City, NJ, 1992.

Heywood, J.B., *Internal Combustin Engine Fundamentals*, 930 pp.,
McGraw-Hill, Inc., New York, NY, 1988.

Hottenstein, L.N., Ship Emissions Control Study for the Ports of Long
Beach and Los Angeles: Marine Vessel Emissions While Hotelling in Port
and Evaluation of Alternative NOx Control Technologies, TRC
Environmental Consultants, Inc., Mission Viejo, CA, 1991.

ISO, Reciprocating Internal Combustion Engines \-- Exhaust Emission
Measurement \-- Part 4: Test Cycles for Different Engine Applications,
International Organization for Standardization, Geneva, Switzerland,
1996.

Laurence, C.A., *Vessel Operating Economies*, 55 pp., Fairplay
Publications Ltd., Coulsdon, Surrey, UK, 1984.

LMIS, Dataset of Ships 100 GRT or Greater, Lloyd\'s Maritime Information
Services, Stamford, CT, 1996.

Lloyd\'s Register, Merchant Shipbuilding Return, Lloyd\'s Register of
Shipping, London, UK, 1970-1994.

MARAD, Outlook for the U.S. Shipbuilding and Repair Industry, Maritime
Administration, U.S. Department of Transportation, Office of Ship
Construction, Washington, DC, 1996.

Markle, S.P., and A.J. Brown, Naval Ship Engine Exhaust Emission
Characterization, *Naval Engineers Journal*, *108* (5), 37-47, 1996.

Osborne, A., Modern Marine Engineer\'s Manual, Cornell Maritime Press,
Centreville, MD, 1943.

Packard, W.V., *Voyage Estimating*, 79 pp., Fairplay Publications Ltd.,
Coulsdon, Surrey, UK, 1991.

Turpin, E.A., and W.A. McEwen, *Merchant Marine Officer\'s Handbook*,
Cornell Maritime Press, Inc., Centreville, MD, 1965.

UNCTAD, Review of Maritime Transport 1994, United Nations, New York and
Geneva, 1995.

USACE, United States Waterway Data, Bureau of Transportation Statistics,
U.S. Department of Transportation, Oak Ridge, Tennessee, 1995.

Wilde Mathews, A., Cargo from Asia Overwhelms Transport, in *Wall Street
Journal*, New York, NY, 1998a.

Wilde Mathews, A., Jet-Age Anomalies, Slowpoke Barges Do Brisk Business,
in *Wall Street Journal*, New York, NY, 1998b.

# APPENDICES

## Method A: Ship Operations Method for 1996 (Pages A2-A8)

## Method B: Cargo Method using 1993 Cargo Trade Data (Pages A9-A18)

## Engine Manufactures and Engine Models in U.S. Flag Fleet (Pages A19-A31)

7.1 METHOD A: Ship Operations Method

1996 U.S. Flag Fleet CI Marine Engines, By EPA Category

  --------------- --------------- ------- -------- -------- -------- -------- -------- --------
  Count of Ships  Category                                                             

  Vessel Service  Uncategorized           1        2        3A       3B       Not      Grand
                                                                              Diesel   Total

  CONTAINER       3                                1                 47       36       87

  FISHING         1926                    766      74       2        10                2778

  PASSENGER       20                      4                 1        2        14       41

  RORO            45                      3        11       8        13       17       97

  TRANSPORT       82                      5        14       12       27       279      419

  TUG             760                     98       391      9        8        3        1269

  UTILITY         277                     241      98       4        3        27       650

  Grand Total     3113                    1117     589      36       110      376      5341

                  58%                     21%      11%      1%       2%       7%       

                                                                                       

  Expected                                                                             
  distribution of                                                                      
  uncategorized                                                                        
  vessels with CI                                                                      
  Marine Engines                                                                       
  by EPA Category                                                                      

  Count of Ships  Category                                                             

  Vessel Service                  1                2        3A       3B       Count of 
                                                                              ships    

  CONTAINER                       \-               1        \-       49       50       

  FISHING                         2,498            241      7        33       2,778    

  PASSENGER                       8                \-       2        4        14       

  RORO                            6                21       15       24       65       

  TRANSPORT                       6                17       15       34       72       

  TUG                             244              975      22       20       1,262    

  UTILITY                         420              171      7        5        603      

  Count of ships                  3,182            1,426    68       168      4,843    
  --------------- --------------- ------- -------- -------- -------- -------- -------- --------

Category 3A engines are equal to or greater than 20 liters per cylinder
and less than 60 liters per cylinder; Category 3B engines are greater
than or equal to 60 liters per cylinder.

1996 U.S. Flag Fleet Fuel-Consumption Estimates (from BHP in metric tons
per day)

  ----------- ----------- --------------- ---------- ------- ------- ---- ------- ----- ------- ---------- ---------- -------
                                                                                                                      

              Average of  Category                                                                                    
              tpd                                                                                                     

              Vessel      Uncategorized   1          2               3A           3B            Weighted              
              Service                                                                           Ave                   

              CONTAINER   36                         19                           101           96                    

              FISHING     12              9          17              23           18            14                    

              PASSENGER   36              17                         18           36            32                    

              RORO        45                         23              87           74            53                    

              TRANSPORT   33              15         22              56           53            40                    

              TUG         14              10         17              44           56            16                    

              UTILITY     15              10         16              36           22            13                    

              Weighted    17              10         17              55           72            20                    
              Ave                                                                                                     

                                                                                                                      

  fuel use                                Category                                                         Weighted   Max
  per                                                                                                      Average    load =
  day-ship                                                                                                            80% max
  (adjusted                                                                                                           power
  for max                                                                                                             
  load)                                                                                                               

  Vessel      Average of                  1          2               3A           3B                                  
  Service     tpd                                                                                                     

  CONTAINER                               \-         15              \-           81            77         80%        

  FISHING                                 7          13              18           14            11         80%        

  PASSENGER                               13         \-              14           29            25         80%        

  RORO                                    \-         18              69           59            42         80%        

  TRANSPORT                               12         17              45           42            32         80%        

  TUG                                     8          14              35           44            13         80%        

  UTILITY                                 8          12              29           18            10         80%        

                                                                                                                      

  fuel use                                Category   E5      E5           E3            E3                 Weighted   
  per                                                Cycle   Cycle        Cycle         Cycle              Average    
  day-ship                                                                                                            
  (with                                                                                                               
  marine duty                                                                                                         
  cycle)                                                                                                              

  Vessel      Average of                  1          2               3A           3B                                  
  Service     tpd                                                                                                     

  CONTAINER                               \-         10              \-           56            55                    

  FISHING                                 5          9               13           10            5                     

  PASSENGER                               9          \-              10           20            12                    

  RORO                                    \-         13              48           40            30                    

  TRANSPORT                               8          12              31           29            23                    

  TUG                                     6          10              24           31            9                     

  UTILITY                                 5          9               20           12            7                     

  Weighted                                5          9               29           34            8                     
  Ave                                                                                                                 
  ----------- ----------- --------------- ---------- ------- ------- ---- ------- ----- ------- ---------- ---------- -------

1996 World Fleet CI Marine Engines, by EPA Category

  ---------------- ---------- -------- -------- --------- --------- ----------
  World Ships                                                       
  Emission                                                          
  Inventory                                                         

  Number of ships  Category                                         

  Vessel Service   ?          1        2        3A        3B        Grand
                                                                    Total

  CONTAINER        983                 2        38        800       1,823

  FISHING          19,895     2,511    619      320       145       23,490

  PASSENGER        2,824      544      35       230       39        3,672

  RORO             2,116      92       87       210       191       2,696

  TRANSPORT        30,685     371      378      1,018     3,594     36,046

  TUG              7,004      847      1,170    180       115       9,316

  UTILITY          5,603      1,190    322      110       67        7,292

  Grand Total      69,110     5,555    2,613    2,106     4,951     84,335

                                                                    

  Statistical                                                       
  distribution of                                                   
  world fleet by                                                    
  engine category                                                   

  Number of ships  Category                                         

  Vessel Service   ?          1        2        3A        3B        Grand
                                                                    Total

  CONTAINER                   \-       4        82        1,736     1,823

  FISHING                     16,407   4,045    2,091     947       23,490

  PASSENGER                   2,356    152      996       169       3,672

  RORO                        428      404      976       888       2,696

  TRANSPORT                   2,495    2,542    6,845     24,165    36,046

  TUG                         3,413    4,714    725       463       9,316

  UTILITY                     5,138    1,390    475       289       7,292

  Grand Total                 30,235   13,251   12,190    28,658    84,335
  ---------------- ---------- -------- -------- --------- --------- ----------

1996 NOx Emission Estimates (fuel-based)

+--------+-----+----+------+------+--------+------+-------+--------+
| (kg    |     |    |      |      |        |      |       |        |
| NOx    |     |    |      |      |        |      |       |        |
| /tonne |     |    |      |      |        |      |       |        |
| fuel)  |     |    |      |      |        |      |       |        |
+--------+-----+----+------+------+--------+------+-------+--------+
| 87     | S   |    |      |      | All    |      |       |        |
|        | low |    |      |      | Ca     |      |       |        |
|        | Sp  |    |      |      | tegory |      |       |        |
|        | eed |    |      |      | 1, 2   |      |       |        |
|        | em  |    |      |      | use    |      |       |        |
|        | iss |    |      |      | Medium |      |       |        |
|        | ion |    |      |      | -speed |      |       |        |
|        | fac |    |      |      | em     |      |       |        |
|        | tor |    |      |      | ission |      |       |        |
|        |     |    |      |      | f      |      |       |        |
|        |     |    |      |      | actors |      |       |        |
|        |     |    |      |      |        |      |       |        |
|        |     |    |      |      | half   |      |       |        |
|        |     |    |      |      | 3A use |      |       |        |
|        |     |    |      |      | M      |      |       |        |
|        |     |    |      |      | edium- |      |       |        |
|        |     |    |      |      | speed, |      |       |        |
|        |     |    |      |      | half   |      |       |        |
|        |     |    |      |      | use    |      |       |        |
|        |     |    |      |      | Slow   |      |       |        |
|        |     |    |      |      | -speed |      |       |        |
|        |     |    |      |      | f      |      |       |        |
|        |     |    |      |      | actors |      |       |        |
+--------+-----+----+------+------+--------+------+-------+--------+
| 57     | Med |    |      |      | cur    |      |       |        |
|        | ium |    |      |      | rently |      |       |        |
|        | Sp  |    |      |      | upper  |      |       |        |
|        | eed |    |      |      | bound  |      |       |        |
|        | em  |    |      |      | emi    |      |       |        |
|        | iss |    |      |      | ssions |      |       |        |
|        | ion |    |      |      | f      |      |       |        |
|        | fac |    |      |      | actors |      |       |        |
|        | tor |    |      |      |        |      |       |        |
+--------+-----+----+------+------+--------+------+-------+--------+
|        |     |    |      |      | s      |      |       |        |
|        |     |    |      |      | imilar |      |       |        |
|        |     |    |      |      | to     |      |       |        |
|        |     |    |      |      | AP-42  |      |       |        |
|        |     |    |      |      | f      |      |       |        |
|        |     |    |      |      | actors |      |       |        |
+--------+-----+----+------+------+--------+------+-------+--------+
| 68%    |     |    |      |      |        |      |       |        |
| ships  |     |    |      |      |        |      |       |        |
| in     |     |    |      |      |        |      |       |        |
| U.S.   |     |    |      |      |        |      |       |        |
| fleet  |     |    |      |      |        |      |       |        |
| in     |     |    |      |      |        |      |       |        |
| volved |     |    |      |      |        |      |       |        |
| in     |     |    |      |      |        |      |       |        |
| f      |     |    |      |      |        |      |       |        |
| oreign |     |    |      |      |        |      |       |        |
| trade, |     |    |      |      |        |      |       |        |
| assume |     |    |      |      |        |      |       |        |
| they   |     |    |      |      |        |      |       |        |
| spend  |     |    |      |      |        |      |       |        |
| 30%    |     |    |      |      |        |      |       |        |
| time   |     |    |      |      |        |      |       |        |
| in     |     |    |      |      |        |      |       |        |
| U.S.   |     |    |      |      |        |      |       |        |
| waters |     |    |      |      |        |      |       |        |
| (from  |     |    |      |      |        |      |       |        |
| Census |     |    |      |      |        |      |       |        |
| data   |     |    |      |      |        |      |       |        |
| on     |     |    |      |      |        |      |       |        |
| Wat    |     |    |      |      |        |      |       |        |
| erways |     |    |      |      |        |      |       |        |
| CD)    |     |    |      |      |        |      |       |        |
+--------+-----+----+------+------+--------+------+-------+--------+
| kg NOx |     | Ca |      |      |        |      | Wei   | U.S.   |
| per    |     | te |      |      |        |      | ghted | Fleet  |
| da     |     | go |      |      |        |      | Av    | in     |
| y-ship |     | ry |      |      |        |      | erage | U.S.   |
|        |     |    |      |      |        |      |       | Waters |
+--------+-----+----+------+------+--------+------+-------+--------+
| Vessel |     |    | 1    | 2    | 3A     | 3B   |       |        |
| S      |     |    |      |      |        |      |       |        |
| ervice |     |    |      |      |        |      |       |        |
+--------+-----+----+------+------+--------+------+-------+--------+
| CON    |     |    | \-   | 304  | \-     | 2    | 2,492 | 52%    |
| TAINER |     |    |      |      |        | ,539 |       |        |
+--------+-----+----+------+------+--------+------+-------+--------+
| F      |     |    | 286  | 528  | 906    | 863  | 315   | 100%   |
| ISHING |     |    |      |      |        |      |       |        |
+--------+-----+----+------+------+--------+------+-------+--------+
| PAS    |     |    | 521  | \-   | 709    | 1    | 890   | 100%   |
| SENGER |     |    |      |      |        | ,717 |       |        |
+--------+-----+----+------+------+--------+------+-------+--------+
| RORO   |     |    | \-   | 376  | 1,802  | 1    | 1,215 | 52%    |
|        |     |    |      |      |        | ,844 |       |        |
+--------+-----+----+------+------+--------+------+-------+--------+
| TRA    |     |    | 247  | 359  | 1,158  | 1    | 964   | 52%    |
| NSPORT |     |    |      |      |        | ,324 |       |        |
+--------+-----+----+------+------+--------+------+-------+--------+
| TUG    |     |    | 315  | 544  | 1,744  | 2    | 555   | 100%   |
|        |     |    |      |      |        | ,660 |       |        |
+--------+-----+----+------+------+--------+------+-------+--------+
| U      |     |    | 312  | 486  | 1,414  | 1    | 381   | 100%   |
| TILITY |     |    |      |      |        | ,075 |       |        |
+--------+-----+----+------+------+--------+------+-------+--------+
| We     |     |    |      | 291  | 530    | 1    | 1,821 | 431    |
| ighted |     |    |      |      |        | ,483 |       |        |
| column |     |    |      |      |        |      |       |        |
| a      |     |    |      |      |        |      |       |        |
| verage |     |    |      |      |        |      |       |        |
+--------+-----+----+------+------+--------+------+-------+--------+
|        |     |    |      |      |        |      |       |        |
+--------+-----+----+------+------+--------+------+-------+--------+
| Assume |     |    |      |      |        |      |       |        |
| 80% of |     |    |      |      |        |      |       |        |
| the    |     |    |      |      |        |      |       |        |
| time   |     |    |      |      |        |      |       |        |
| un     |     |    |      |      |        |      |       |        |
| derway |     |    |      |      |        |      |       |        |
+--------+-----+----+------+------+--------+------+-------+--------+
| Est    |     | Ca |      |      |        |      | Total | P      |
| imated |     | te |      |      |        |      |       | ercent |
| annual |     | go |      |      |        |      |       | un     |
| emi    |     | ry |      |      |        |      |       | derway |
| ssions |     |    |      |      |        |      |       |        |
+--------+-----+----+------+------+--------+------+-------+--------+
| Vessel | kg  |    | 1    | 2    | 3A     | 3B   |       |        |
| S      | NOx |    |      |      |        |      |       |        |
| ervice | /yr |    |      |      |        |      |       |        |
+--------+-----+----+------+------+--------+------+-------+--------+
| CON    |     |    | \-   | 92   | \-     | 36   | 36,17 | 80%    |
| TAINER |     |    |      | ,007 |        | ,085 | 7,501 |        |
|        |     |    |      |      |        | ,495 |       |        |
+--------+-----+----+------+------+--------+------+-------+--------+
| F      |     |    | 208  | 37   | 1,7    | 8    | 2     | 80%    |
| ISHING |     |    | ,365 | ,192 | 25,533 | ,211 | 55,49 |        |
|        |     |    | ,719 | ,614 |        | ,745 | 5,611 |        |
+--------+-----+----+------+------+--------+------+-------+--------+
| PAS    |     |    | 1    | \-   | 4      | 1    | 3,55  | 80%    |
| SENGER |     |    | ,188 |      | 04,118 | ,958 | 0,915 |        |
|        |     |    | ,750 |      |        | ,047 |       |        |
+--------+-----+----+------+------+--------+------+-------+--------+
| RORO   |     |    | \-   | 2    | 7,8    | 13   | 23,16 | 80%    |
|        |     |    |      | ,254 | 51,187 | ,060 | 6,895 |        |
|        |     |    |      | ,833 |        | ,875 |       |        |
+--------+-----+----+------+------+--------+------+-------+--------+
| TRA    |     |    | 448  | 1    | 5,0    | 12   | 20,29 | 80%    |
| NSPORT |     |    | ,424 | ,822 | 43,205 | ,976 | 0,383 |        |
|        |     |    |      | ,588 |        | ,166 |       |        |
+--------+-----+----+------+------+--------+------+-------+--------+
| TUG    |     |    | 22   | 154  | 11,4   | 15   | 2     | 80%    |
|        |     |    | ,470 | ,898 | 29,244 | ,492 | 04,29 |        |
|        |     |    | ,502 | ,115 |        | ,259 | 0,119 |        |
+--------+-----+----+------+------+--------+------+-------+--------+
| U      |     |    | 38   | 24   | 2,8    | 1    | 67,00 | 80%    |
| TILITY |     |    | ,240 | ,246 | 78,947 | ,641 | 7,980 |        |
|        |     |    | ,282 | ,987 |        | ,764 |       |        |
+--------+-----+----+------+------+--------+------+-------+--------+
| Total  |     |    | 270  | 220  | 29,3   | 89   | 6     |        |
|        |     |    | ,713 | ,507 | 32,232 | ,426 | 09,97 |        |
|        |     |    | ,677 | ,144 |        | ,350 | 9,403 |        |
+--------+-----+----+------+------+--------+------+-------+--------+

1996 PM Emission Estimates (fuel-based)

+--------+-----+------+------+------+------+------+------+--------+
| (kg    |     |      |      |      |      |      |      |        |
| PM     |     |      |      |      |      |      |      |        |
| /tonne |     |      |      |      |      |      |      |        |
| fuel)  |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| 7.6    | S   |      |      |      | All  |      |      |        |
|        | low |      |      |      | Cate |      |      |        |
|        | Sp  |      |      |      | gory |      |      |        |
|        | eed |      |      |      | 1, 2 |      |      |        |
|        | em  |      |      |      | use  |      |      |        |
|        | iss |      |      |      | Medi |      |      |        |
|        | ion |      |      |      | um-s |      |      |        |
|        | fac |      |      |      | peed |      |      |        |
|        | tor |      |      |      | emis |      |      |        |
|        |     |      |      |      | sion |      |      |        |
|        |     |      |      |      | fac  |      |      |        |
|        |     |      |      |      | tors |      |      |        |
|        |     |      |      |      |      |      |      |        |
|        |     |      |      |      | half |      |      |        |
|        |     |      |      |      | 3A   |      |      |        |
|        |     |      |      |      | use  |      |      |        |
|        |     |      |      |      | M    |      |      |        |
|        |     |      |      |      | ediu |      |      |        |
|        |     |      |      |      | m-sp |      |      |        |
|        |     |      |      |      | eed, |      |      |        |
|        |     |      |      |      | half |      |      |        |
|        |     |      |      |      | use  |      |      |        |
|        |     |      |      |      | Sl   |      |      |        |
|        |     |      |      |      | ow-s |      |      |        |
|        |     |      |      |      | peed |      |      |        |
|        |     |      |      |      | fac  |      |      |        |
|        |     |      |      |      | tors |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| 1.2    | Med |      |      |      | c    |      |      |        |
|        | ium |      |      |      | urre |      |      |        |
|        | Sp  |      |      |      | ntly |      |      |        |
|        | eed |      |      |      | u    |      |      |        |
|        | em  |      |      |      | pper |      |      |        |
|        | iss |      |      |      | b    |      |      |        |
|        | ion |      |      |      | ound |      |      |        |
|        | fac |      |      |      | e    |      |      |        |
|        | tor |      |      |      | miss |      |      |        |
|        |     |      |      |      | ions |      |      |        |
|        |     |      |      |      | fac  |      |      |        |
|        |     |      |      |      | tors |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
|        |     |      |      |      | sim  |      |      |        |
|        |     |      |      |      | ilar |      |      |        |
|        |     |      |      |      | to   |      |      |        |
|        |     |      |      |      | A    |      |      |        |
|        |     |      |      |      | P-42 |      |      |        |
|        |     |      |      |      | fac  |      |      |        |
|        |     |      |      |      | tors |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| 68%    |     |      |      |      |      |      |      |        |
| ships  |     |      |      |      |      |      |      |        |
| in     |     |      |      |      |      |      |      |        |
| U.S.   |     |      |      |      |      |      |      |        |
| fleet  |     |      |      |      |      |      |      |        |
| in     |     |      |      |      |      |      |      |        |
| volved |     |      |      |      |      |      |      |        |
| in     |     |      |      |      |      |      |      |        |
| f      |     |      |      |      |      |      |      |        |
| oreign |     |      |      |      |      |      |      |        |
| trade, |     |      |      |      |      |      |      |        |
| assume |     |      |      |      |      |      |      |        |
| they   |     |      |      |      |      |      |      |        |
| spend  |     |      |      |      |      |      |      |        |
| 30%    |     |      |      |      |      |      |      |        |
| time   |     |      |      |      |      |      |      |        |
| in     |     |      |      |      |      |      |      |        |
| U.S.   |     |      |      |      |      |      |      |        |
| waters |     |      |      |      |      |      |      |        |
| (from  |     |      |      |      |      |      |      |        |
| Census |     |      |      |      |      |      |      |        |
| data)  |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| kg PM  |     | Cate |      |      |      |      | Weig | U.S.   |
| per    |     | gory |      |      |      |      | hted | Fleet  |
| da     |     |      |      |      |      |      |      | in     |
| y-ship |     |      |      |      |      |      | Ave  | U.S.   |
|        |     |      |      |      |      |      | rage | Waters |
+--------+-----+------+------+------+------+------+------+--------+
| Vessel | D   |      | 1    | 2    | 3A   | 3B   |      |        |
| S      | ata |      |      |      |      |      |      |        |
| ervice |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| CON    |     |      | \-   | 6    | \-   | 222  | 217  | 52%    |
| TAINER |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| F      |     |      | 6    | 11   | 55   | 75   | 7    | 100%   |
| ISHING |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| PAS    |     |      | 11   | \-   | 43   | 150  | 55   | 100%   |
| SENGER |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| RORO   |     |      | \-   | 8    | 110  | 161  | 88   | 52%    |
+--------+-----+------+------+------+------+------+------+--------+
| TRA    |     |      | 5    | 8    | 71   | 116  | 71   | 52%    |
| NSPORT |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| TUG    |     |      | 7    | 11   | 107  | 232  | 16   | 100%   |
+--------+-----+------+------+------+------+------+------+--------+
| U      |     |      | 7    | 10   | 86   | 94   | 9    | 100%   |
| TILITY |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| We     |     |      |      | 6    | 11   | 91   | 159  | 14     |
| ighted |     |      |      |      |      |      |      |        |
| column |     |      |      |      |      |      |      |        |
| a      |     |      |      |      |      |      |      |        |
| verage |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
|        |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| Assume |     |      |      |      |      |      |      |        |
| 80% of |     |      |      |      |      |      |      |        |
| the    |     |      |      |      |      |      |      |        |
| time   |     |      |      |      |      |      |      |        |
| un     |     |      |      |      |      |      |      |        |
| derway |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| Est    |     | Cate |      |      |      |      | T    | P      |
| imated |     | gory |      |      |      |      | otal | ercent |
| annual |     |      |      |      |      |      |      | un     |
| emi    |     |      |      |      |      |      |      | derway |
| ssions |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| Vessel | kg  |      | 1    | 2    | 3A   | 3B   |      |        |
| S      | PM  |      |      |      |      |      |      |        |
| ervice | /yr |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| CON    |     |      | \-   | 1    | \-   | 3    | 3    | 80%    |
| TAINER |     |      |      | ,937 |      | ,152 | ,154 |        |
|        |     |      |      |      |      | ,296 | ,233 |        |
+--------+-----+------+------+------+------+------+------+--------+
| F      |     |      | 4    | 783  | 105  | 717  | 5    | 80%    |
| ISHING |     |      | ,386 | ,002 | ,449 | ,348 | ,992 |        |
|        |     |      | ,647 |      |      |      | ,446 |        |
+--------+-----+------+------+------+------+------+------+--------+
| PAS    |     |      | 25   | \-   | 24   | 171  | 220  | 80%    |
| SENGER |     |      | ,026 |      | ,696 | ,048 | ,770 |        |
+--------+-----+------+------+------+------+------+------+--------+
| RORO   |     |      | \-   | 47   | 479  | 1    | 1    | 80%    |
|        |     |      |      | ,470 | ,795 | ,140 | ,668 |        |
|        |     |      |      |      |      | ,950 | ,215 |        |
+--------+-----+------+------+------+------+------+------+--------+
| TRA    |     |      | 9    | 38   | 308  | 1    | 1    | 80%    |
| NSPORT |     |      | ,441 | ,370 | ,196 | ,133 | ,489 |        |
|        |     |      |      |      |      | ,550 | ,557 |        |
+--------+-----+------+------+------+------+------+------+--------+
| TUG    |     |      | 473  | 3    | 698  | 1    | 5    | 80%    |
|        |     |      | ,063 | ,261 | ,454 | ,353 | ,785 |        |
|        |     |      |      | ,013 |      | ,347 | ,877 |        |
+--------+-----+------+------+------+------+------+------+--------+
| U      |     |      | 805  | 510  | 175  | 143  | 1    | 80%    |
| TILITY |     |      | ,059 | ,463 | ,936 | ,418 | ,634 |        |
|        |     |      |      |      |      |      | ,876 |        |
+--------+-----+------+------+------+------+------+------+--------+
| Total  |     |      | 5    | 4    | 1    | 7    | 19   |        |
|        |     |      | ,699 | ,642 | ,792 | ,811 | ,945 |        |
|        |     |      | ,235 | ,256 | ,525 | ,957 | ,973 |        |
+--------+-----+------+------+------+------+------+------+--------+

1996 HC Emission Estimates (fuel-based)

+--------+-----+------+------+------+------+------+------+--------+
| (kg    |     |      |      |      |      |      |      |        |
| HC     |     |      |      |      |      |      |      |        |
| /tonne |     |      |      |      |      |      |      |        |
| fuel)  |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| 2.4    | S   |      |      |      | All  |      |      |        |
|        | low |      |      |      | Cate |      |      |        |
|        | Sp  |      |      |      | gory |      |      |        |
|        | eed |      |      |      | 1, 2 |      |      |        |
|        | em  |      |      |      | use  |      |      |        |
|        | iss |      |      |      | Medi |      |      |        |
|        | ion |      |      |      | um-s |      |      |        |
|        | fac |      |      |      | peed |      |      |        |
|        | tor |      |      |      | emis |      |      |        |
|        |     |      |      |      | sion |      |      |        |
|        |     |      |      |      | fac  |      |      |        |
|        |     |      |      |      | tors |      |      |        |
|        |     |      |      |      |      |      |      |        |
|        |     |      |      |      | half |      |      |        |
|        |     |      |      |      | 3A   |      |      |        |
|        |     |      |      |      | use  |      |      |        |
|        |     |      |      |      | M    |      |      |        |
|        |     |      |      |      | ediu |      |      |        |
|        |     |      |      |      | m-sp |      |      |        |
|        |     |      |      |      | eed, |      |      |        |
|        |     |      |      |      | half |      |      |        |
|        |     |      |      |      | use  |      |      |        |
|        |     |      |      |      | Sl   |      |      |        |
|        |     |      |      |      | ow-s |      |      |        |
|        |     |      |      |      | peed |      |      |        |
|        |     |      |      |      | fac  |      |      |        |
|        |     |      |      |      | tors |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| 2.4    | Med |      |      |      | c    |      |      |        |
|        | ium |      |      |      | urre |      |      |        |
|        | Sp  |      |      |      | ntly |      |      |        |
|        | eed |      |      |      | u    |      |      |        |
|        | em  |      |      |      | pper |      |      |        |
|        | iss |      |      |      | b    |      |      |        |
|        | ion |      |      |      | ound |      |      |        |
|        | fac |      |      |      | e    |      |      |        |
|        | tor |      |      |      | miss |      |      |        |
|        |     |      |      |      | ions |      |      |        |
|        |     |      |      |      | fac  |      |      |        |
|        |     |      |      |      | tors |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
|        |     |      |      |      | sim  |      |      |        |
|        |     |      |      |      | ilar |      |      |        |
|        |     |      |      |      | to   |      |      |        |
|        |     |      |      |      | A    |      |      |        |
|        |     |      |      |      | P-42 |      |      |        |
|        |     |      |      |      | fac  |      |      |        |
|        |     |      |      |      | tors |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| 68%    |     |      |      |      |      |      |      |        |
| ships  |     |      |      |      |      |      |      |        |
| in     |     |      |      |      |      |      |      |        |
| U.S.   |     |      |      |      |      |      |      |        |
| fleet  |     |      |      |      |      |      |      |        |
| in     |     |      |      |      |      |      |      |        |
| volved |     |      |      |      |      |      |      |        |
| in     |     |      |      |      |      |      |      |        |
| f      |     |      |      |      |      |      |      |        |
| oreign |     |      |      |      |      |      |      |        |
| trade, |     |      |      |      |      |      |      |        |
| assume |     |      |      |      |      |      |      |        |
| they   |     |      |      |      |      |      |      |        |
| spend  |     |      |      |      |      |      |      |        |
| 30%    |     |      |      |      |      |      |      |        |
| time   |     |      |      |      |      |      |      |        |
| in     |     |      |      |      |      |      |      |        |
| U.S.   |     |      |      |      |      |      |      |        |
| waters |     |      |      |      |      |      |      |        |
| (from  |     |      |      |      |      |      |      |        |
| Census |     |      |      |      |      |      |      |        |
| data)  |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| kg HC  |     | Cate |      |      |      |      | Weig | U.S.   |
| per    |     | gory |      |      |      |      | hted | Fleet  |
| da     |     |      |      |      |      |      |      | in     |
| y-ship |     |      |      |      |      |      | Ave  | U.S.   |
|        |     |      |      |      |      |      | rage | Waters |
+--------+-----+------+------+------+------+------+------+--------+
| Vessel | D   |      | 1    | 2    | 3A   | 3B   |      |        |
| S      | ata |      |      |      |      |      |      |        |
| ervice |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| CON    |     |      | \-   | 13   | \-   | 70   | 69   | 52%    |
| TAINER |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| F      |     |      | 12   | 22   | 30   | 24   | 13   | 100%   |
| ISHING |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| PAS    |     |      | 22   | \-   | 24   | 47   | 29   | 100%   |
| SENGER |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| RORO   |     |      | \-   | 16   | 60   | 51   | 38   | 52%    |
+--------+-----+------+------+------+------+------+------+--------+
| TRA    |     |      | 10   | 15   | 39   | 37   | 30   | 52%    |
| NSPORT |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| TUG    |     |      | 13   | 23   | 58   | 73   | 22   | 100%   |
+--------+-----+------+------+------+------+------+------+--------+
| U      |     |      | 13   | 20   | 47   | 30   | 16   | 100%   |
| TILITY |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| We     |     |      |      | 12   | 22   | 49   | 50   | 17     |
| ighted |     |      |      |      |      |      |      |        |
| column |     |      |      |      |      |      |      |        |
| a      |     |      |      |      |      |      |      |        |
| verage |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
|        |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| Assume |     |      |      |      |      |      |      |        |
| 80% of |     |      |      |      |      |      |      |        |
| the    |     |      |      |      |      |      |      |        |
| time   |     |      |      |      |      |      |      |        |
| un     |     |      |      |      |      |      |      |        |
| derway |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| Est    |     | Cate |      |      |      |      | T    | P      |
| imated |     | gory |      |      |      |      | otal | ercent |
| annual |     |      |      |      |      |      |      | un     |
| emi    |     |      |      |      |      |      |      | derway |
| ssions |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| Vessel | kg  |      | 1    | 2    | 3A   | 3B   |      |        |
| S      | HC  |      |      |      |      |      |      |        |
| ervice | /yr |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| CON    |     |      | \-   | 3    | \-   | 995  | 999  | 80%    |
| TAINER |     |      |      | ,874 |      | ,462 | ,336 |        |
+--------+-----+------+------+------+------+------+------+--------+
| F      |     |      | 8    | 1    | 57   | 226  | 10   | 80%    |
| ISHING |     |      | ,773 | ,566 | ,518 | ,531 | ,623 |        |
|        |     |      | ,293 | ,005 |      |      | ,347 |        |
+--------+-----+------+------+------+------+------+------+--------+
| PAS    |     |      | 50   | \-   | 13   | 54   | 117  | 80%    |
| SENGER |     |      | ,053 |      | ,471 | ,015 | ,538 |        |
+--------+-----+------+------+------+------+------+------+--------+
| RORO   |     |      | \-   | 94   | 261  | 360  | 716  | 80%    |
|        |     |      |      | ,940 | ,706 | ,300 | ,947 |        |
+--------+-----+------+------+------+------+------+------+--------+
| TRA    |     |      | 18   | 76   | 168  | 357  | 621  | 80%    |
| NSPORT |     |      | ,881 | ,741 | ,107 | ,963 | ,692 |        |
+--------+-----+------+------+------+------+------+------+--------+
| TUG    |     |      | 946  | 6    | 380  | 427  | 8    | 80%    |
|        |     |      | ,126 | ,522 | ,975 | ,373 | ,276 |        |
|        |     |      |      | ,026 |      |      | ,500 |        |
+--------+-----+------+------+------+------+------+------+--------+
| U      |     |      | 1    | 1    | 95   | 45   | 2    | 80%    |
| TILITY |     |      | ,610 | ,020 | ,965 | ,290 | ,772 |        |
|        |     |      | ,117 | ,926 |      |      | ,298 |        |
+--------+-----+------+------+------+------+------+------+--------+
| Total  |     |      | 11   | 9    | 977  | 2    | 24   |        |
|        |     |      | ,398 | ,284 | ,741 | ,466 | ,127 |        |
|        |     |      | ,471 | ,511 |      | ,934 | ,657 |        |
+--------+-----+------+------+------+------+------+------+--------+

1996 CO Emission Estimates

+--------+-----+------+------+------+------+------+------+--------+
| (kg    |     |      |      |      |      |      |      |        |
| CO     |     |      |      |      |      |      |      |        |
| /tonne |     |      |      |      |      |      |      |        |
| fuel)  |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| 7.4    | S   |      |      |      | All  |      |      |        |
|        | low |      |      |      | Cate |      |      |        |
|        | Sp  |      |      |      | gory |      |      |        |
|        | eed |      |      |      | 1, 2 |      |      |        |
|        | em  |      |      |      | use  |      |      |        |
|        | iss |      |      |      | Medi |      |      |        |
|        | ion |      |      |      | um-s |      |      |        |
|        | fac |      |      |      | peed |      |      |        |
|        | tor |      |      |      | emis |      |      |        |
|        |     |      |      |      | sion |      |      |        |
|        |     |      |      |      | fac  |      |      |        |
|        |     |      |      |      | tors |      |      |        |
|        |     |      |      |      |      |      |      |        |
|        |     |      |      |      | half |      |      |        |
|        |     |      |      |      | 3A   |      |      |        |
|        |     |      |      |      | use  |      |      |        |
|        |     |      |      |      | M    |      |      |        |
|        |     |      |      |      | ediu |      |      |        |
|        |     |      |      |      | m-sp |      |      |        |
|        |     |      |      |      | eed, |      |      |        |
|        |     |      |      |      | half |      |      |        |
|        |     |      |      |      | use  |      |      |        |
|        |     |      |      |      | Sl   |      |      |        |
|        |     |      |      |      | ow-s |      |      |        |
|        |     |      |      |      | peed |      |      |        |
|        |     |      |      |      | fac  |      |      |        |
|        |     |      |      |      | tors |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| 7.4    | Med |      |      |      | c    |      |      |        |
|        | ium |      |      |      | urre |      |      |        |
|        | Sp  |      |      |      | ntly |      |      |        |
|        | eed |      |      |      | u    |      |      |        |
|        | em  |      |      |      | pper |      |      |        |
|        | iss |      |      |      | b    |      |      |        |
|        | ion |      |      |      | ound |      |      |        |
|        | fac |      |      |      | e    |      |      |        |
|        | tor |      |      |      | miss |      |      |        |
|        |     |      |      |      | ions |      |      |        |
|        |     |      |      |      | fac  |      |      |        |
|        |     |      |      |      | tors |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
|        |     |      |      |      | sim  |      |      |        |
|        |     |      |      |      | ilar |      |      |        |
|        |     |      |      |      | to   |      |      |        |
|        |     |      |      |      | A    |      |      |        |
|        |     |      |      |      | P-42 |      |      |        |
|        |     |      |      |      | fac  |      |      |        |
|        |     |      |      |      | tors |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| 68%    |     |      |      |      |      |      |      |        |
| ships  |     |      |      |      |      |      |      |        |
| in     |     |      |      |      |      |      |      |        |
| U.S.   |     |      |      |      |      |      |      |        |
| fleet  |     |      |      |      |      |      |      |        |
| in     |     |      |      |      |      |      |      |        |
| volved |     |      |      |      |      |      |      |        |
| in     |     |      |      |      |      |      |      |        |
| f      |     |      |      |      |      |      |      |        |
| oreign |     |      |      |      |      |      |      |        |
| trade, |     |      |      |      |      |      |      |        |
| assume |     |      |      |      |      |      |      |        |
| they   |     |      |      |      |      |      |      |        |
| spend  |     |      |      |      |      |      |      |        |
| 30%    |     |      |      |      |      |      |      |        |
| time   |     |      |      |      |      |      |      |        |
| in     |     |      |      |      |      |      |      |        |
| U.S.   |     |      |      |      |      |      |      |        |
| waters |     |      |      |      |      |      |      |        |
| (from  |     |      |      |      |      |      |      |        |
| Census |     |      |      |      |      |      |      |        |
| data)  |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| kg CO  |     | Cate |      |      |      |      | Weig | U.S.   |
| per    |     | gory |      |      |      |      | hted | Fleet  |
| da     |     |      |      |      |      |      | Ave  | in     |
| y-ship |     |      |      |      |      |      | rage | U.S.   |
|        |     |      |      |      |      |      |      | Waters |
+--------+-----+------+------+------+------+------+------+--------+
| Vessel | D   |      | 1    | 2    | 3A   | 3B   |      |        |
| S      | ata |      |      |      |      |      |      |        |
| ervice |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| CON    |     |      | \-   | 39   | \-   | 216  | 212  | 52%    |
| TAINER |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| F      |     |      | 37   | 69   | 93   | 73   | 40   | 100%   |
| ISHING |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| PAS    |     |      | 68   | \-   | 73   | 146  | 91   | 100%   |
| SENGER |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| RORO   |     |      | \-   | 49   | 185  | 157  | 116  | 52%    |
+--------+-----+------+------+------+------+------+------+--------+
| TRA    |     |      | 32   | 47   | 119  | 113  | 91   | 52%    |
| NSPORT |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| TUG    |     |      | 41   | 71   | 179  | 226  | 69   | 100%   |
+--------+-----+------+------+------+------+------+------+--------+
| U      |     |      | 40   | 63   | 145  | 91   | 49   | 100%   |
| TILITY |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| We     |     |      |      | 38   | 69   | 152  | 155  | 53     |
| ighted |     |      |      |      |      |      |      |        |
| column |     |      |      |      |      |      |      |        |
| a      |     |      |      |      |      |      |      |        |
| verage |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
|        |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| Assume |     |      |      |      |      |      |      |        |
| 80% of |     |      |      |      |      |      |      |        |
| the    |     |      |      |      |      |      |      |        |
| time   |     |      |      |      |      |      |      |        |
| un     |     |      |      |      |      |      |      |        |
| derway |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| Est    |     | Cate |      |      |      |      |      | P      |
| imated |     | gory |      |      |      |      |      | ercent |
| annual |     |      |      |      |      |      |      | un     |
| emi    |     |      |      |      |      |      |      | derway |
| ssions |     |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| Vessel | kg  |      | 1    | 2    | 3A   | 3B   | T    |        |
| S      | CO  |      |      |      |      |      | otal |        |
| ervice | /yr |      |      |      |      |      |      |        |
+--------+-----+------+------+------+------+------+------+--------+
| CON    |     |      | \-   | 11   | \-   | 3    | 3    | 80%    |
| TAINER |     |      |      | ,945 |      | ,069 | ,081 |        |
|        |     |      |      |      |      | ,341 | ,286 |        |
+--------+-----+------+------+------+------+------+------+--------+
| F      |     |      | 27   | 4    | 177  | 698  | 32   | 80%    |
| ISHING |     |      | ,050 | ,828 | ,346 | ,470 | ,755 |        |
|        |     |      | ,988 | ,515 |      |      | ,320 |        |
+--------+-----+------+------+------+------+------+------+--------+
| PAS    |     |      | 154  | \-   | 41   | 166  | 362  | 80%    |
| SENGER |     |      | ,329 |      | ,534 | ,547 | ,410 |        |
+--------+-----+------+------+------+------+------+------+--------+
| RORO   |     |      | \-   | 292  | 806  | 1    | 2    | 80%    |
|        |     |      |      | ,733 | ,928 | ,110 | ,210 |        |
|        |     |      |      |      |      | ,925 | ,585 |        |
+--------+-----+------+------+------+------+------+------+--------+
| TRA    |     |      | 58   | 236  | 518  | 1    | 1    | 80%    |
| NSPORT |     |      | ,216 | ,617 | ,329 | ,103 | ,916 |        |
|        |     |      |      |      |      | ,720 | ,882 |        |
+--------+-----+------+------+------+------+------+------+--------+
| TUG    |     |      | 2    | 20   | 1    | 1    | 25   | 80%    |
|        |     |      | ,917 | ,109 | ,174 | ,317 | ,519 |        |
|        |     |      | ,223 | ,580 | ,672 | ,732 | ,208 |        |
+--------+-----+------+------+------+------+------+------+--------+
| U      |     |      | 4    | 3    | 295  | 139  | 8    | 80%    |
| TILITY |     |      | ,964 | ,147 | ,892 | ,644 | ,547 |        |
|        |     |      | ,528 | ,854 |      |      | ,918 |        |
+--------+-----+------+------+------+------+------+------+--------+
| Total  |     |      | 35   | 28   | 3    | 7    | 74   |        |
| A      |     |      | ,145 | ,627 | ,014 | ,606 | ,393 |        |
| verage |     |      | ,284 | ,243 | ,702 | ,379 | ,608 |        |
+--------+-----+------+------+------+------+------+------+--------+

7.2 Method B: Cargo Method using 1993 Cargo Trade Data

NOx Emissions (as NOx) Before Adjustments for Steam (non-CI) Engines in
U.S. Fleet

  --------------------------- ----------------- ------------ -----------------
  Oceans (Foreign and                                        
  Domestic)                                                  

  1,691                       kg NOx per                     
                              day-cargo-ship                 

  34,837                      Ave DWT per ship               

  0.5                         cargo capacity                 
                              factor                         

  308                         miles per day                  

  0.00031                     kg emissions per               
                              ton-mile                       

  764,927,137,344             ton-miles on                   
                              ocean/coastwise                

  240,949,607                 kg emissions per               
                              year                           

  49%                         Coastwise                      
                              (domestic tons)                

  51%                         Oceangoing                     
                              (foreign tons)                 

  Great Lakes                                                

  1,691                       kg NOx per                     
                              day-cargo-ship                 

  34,837                      Ave DWT per ship               

  0.6                         cargo capacity                 
                              factor                         

  308                         miles per day                  

  0.00026                     kg emissions per               
                              ton-mile                       

  85,256,307,371              ton-miles on                   
                              Great Lakes                    

  22,379,554                  kg emissions per               
                              year                           

  81%                         domestic tons                  

  19%                         foreign tons                   

  Inland Rivers (Uses U.S.                                   
  Fleet Emissions for                                        
  Category 1, 2, 3A Engines)                                 

  744                         kg NOx per                     
                              day-cargo-ship                 

  15,454                      Ave DWT per ship               

  0.6                         cargo capacity                 
                              factor                         

  191                         miles per day                  

  0.00042                     kg emissions per               
                              ton-mile                       

  494,368,733,957             ton-miles on                   
                              Inland Rivers                  

  207,661,859                 kg emissions per               
                              year                           

  70%                         domestic tons                  

  30%                         foreign tons                   

  470,991,020                 total national                 

  281,435,600                 total domestic                 

  189,555,420                 foreign                        
  --------------------------- ----------------- ------------ -----------------

Miles per day were converted from nautical miles to statute miles for
these calculations.

PM Emissions Before Adjustments for Steam (non-CI) Engines in U.S. Fleet

  --------------------------- -------------------------------------------
  Oceans (Foreign and         
  Domestic)                   

  138                         kg PM per day-cargo-ship

  34,837                      Ave DWT per ship

  0.5                         cargo capacity factor

  308                         miles per day

  0.00003                     kg emissions per ton-mile

  764,927,137,344             ton-miles on ocean/coastwise

  19,610,143                  kg emissions per year

  49%                         Coastwise (domestic tons)

  51%                         Oceangoing (foreign tons)

  Great Lakes                 

  138                         kg PM per day-cargo-ship

  34,837                      Ave DWT per ship

  0.6                         cargo capacity factor

  308                         miles per day

  0.00002                     kg emissions per ton-mile

  85,256,307,371              ton-miles on Great Lakes

  1,821,403                   kg emissions per year

  81%                         domestic tons

  19%                         foreign tons

  Inland Rivers (Uses U.S.    
  Fleet Emissions for         
  Category 1, 2, 3A Engines)  

  38                          kg PM per day-cargo-ship

  15,454                      Ave DWT per ship

  0.6                         cargo capacity factor

  191                         miles per day

  0.00002                     kg emissions per ton-mile

  494,368,733,957             ton-miles on Inland Rivers

  10,496,888                  kg emissions per year

  70%                         domestic tons

  30%                         foreign tons

  31,928,433                  total national

  18,447,527                  total domestic

  13,480,906                  foreign
  --------------------------- -------------------------------------------

Miles per day were converted from nautical miles to statute miles for
these calculations.

HC Emissions Before Adjustments for Steam (non-CI) Engines in U.S. Fleet

  --------------------------- ----------------- ------------------------------
  Oceans (Foreign and                           
  Domestic)                                     

  49                          kg HC per         
                              day-cargo-ship    

  34,837                      Ave DWT per ship  

  0.5                         cargo capacity    
                              factor            

  308                         miles per day     

  0.00001                     kg emissions per  
                              ton-mile          

  764,927,137,344             ton-miles on      
                              ocean/coastwise   

  6,961,848                   kg emissions per  
                              year              

  49%                         Coastwise         
                              (domestic tons)   

  51%                         Oceangoing        
                              (foreign tons)    

  Great Lakes                                   

  49                          kg HC per         
                              day-cargo-ship    

  34,837                      Ave DWT per ship  

  0.6                         cargo capacity    
                              factor            

  308                         miles per day     

  0.00001                     kg emissions per  
                              ton-mile          

  85,256,307,371              ton-miles on      
                              Great Lakes       

  646,621                     kg emissions per  
                              year              

  81%                         domestic tons     

  19%                         foreign tons      

  Inland Rivers (Uses U.S.                      
  Fleet Emissions for                           
  Category 1, 2, 3A Engines)                    

  27                          kg HC per         
                              day-cargo-ship    

  15,454                      Ave DWT per ship  

  0.6                         cargo capacity    
                              factor            

  191                         miles per day     

  0.00001                     kg emissions per  
                              ton-mile          

  494,368,733,957             ton-miles on      
                              Inland Rivers     

  7,402,403                   kg emissions per  
                              year              

  70%                         domestic tons     

  30%                         foreign tons      

  15,010,872                  total national    

  9,107,752                   total domestic    

  5,903,120                   foreign           
  --------------------------- ----------------- ------------------------------

Miles per day were converted from nautical miles to statute miles for
these calculations.

CO Emissions (as CO) Before Adjustments for Steam (non-CI) Engines in
U.S. Fleet

  --------------------------- -------------------------------------------
  Oceans (Foreign and         
  Domestic)                   

  151                         kg CO per day-cargo-ship

  34,837                      Ave DWT per ship

  0.5                         cargo capacity factor

  308                         miles per day

  0.00003                     kg emissions per ton-mile

  764,927,137,344             ton-miles on ocean/coastwise

  21,465,698                  kg emissions per year

  49%                         Coastwise (domestic tons)

  51%                         Oceangoing (foreign tons)

  Great Lakes                 

  151                         kg CO per day-cargo-ship

  34,837                      Ave DWT per ship

  0.6                         cargo capacity factor

  308                         miles per day

  0.00002                     kg emissions per ton-mile

  85,256,307,371              ton-miles on Great Lakes

  1,993,748                   kg emissions per year

  81%                         domestic tons

  19%                         foreign tons

  Inland Rivers (Uses U.S.    
  Fleet Emissions for         
  Category 1, 2, 3A Engines)  

  82                          kg CO per day-cargo-ship

  15,454                      Ave DWT per ship

  0.6                         cargo capacity factor

  191                         miles per day

  0.00005                     kg emissions per ton-mile

  494,368,733,957             ton-miles on Inland Rivers

  22,824,077                  kg emissions per year

  70%                         domestic tons

  30%                         foreign tons

  46,283,524                  total national

  28,082,236                  total domestic

  18,201,288                  foreign
  --------------------------- -------------------------------------------

Miles per day were converted from nautical miles to statute miles for
these calculations.

  ----------- ---------------------- ------------- ------------ ------------ ------------
  Rough                                                                      
  Emissions                                                                  
  using Cargo                                                                
  Method                                                                     
  (assumes                                                                   
  all cargo                                                                  
  carried by                                                                 
  CI Engines)                                                                

                                     kg NOx per    kg PM per    kg HC per    kg CO per
                                     year          year         year         year

              Region                 NOx           PM           HC           CO

              Oceangoing (foreign    122,084,298   9,936,063    3,527,428    10,876,236
              tons)                                                          

              US Flag CI Engines     18,281,433    1,487,869    528,212      1,628,655

              Foreign Flag CI        103,802,866   8,448,194    2,999,215    9,247,581
              Engines                                                        

              Coastwise (domestic    118,865,309   9,674,080    3,434,420    10,589,463
              tons)                                                          

              Inland Rivers          207,661,859   10,496,888   7,402,403    22,824,077

              US Flag CI Engines     175,642,270   8,878,362    6,261,019    19,304,810

              Foreign Flag CI        32,019,589    1,618,526    1,141,384    3,519,267
              Engines                                                        

              Great Lakes            22,379,554    1,821,403    646,621      1,993,748

              US Flag CI Engines     21,478,650    1,748,081    620,591      1,913,488

              Foreign Flag CI        900,904       73,322       26,030       80,260
              Engines                                                        

              Total Nationwide       470,991,020   31,928,433   15,010,872   46,283,524
              Emissions                                                      

              US Flag CI Engines     334,267,661   21,788,392   10,844,243   33,436,416

              Foreign Flag CI        136,723,359   10,140,041   4,166,630    12,847,108
              Engines                                                        
  ----------- ---------------------- ------------- ------------ ------------ ------------

  ------------- ------- ----------- ----- -- ----------- ----- -- ------------ --- -- ------------ -- --- ------------- -- --- ----- --- ------
                                                                                                                                         

  Estimated                                                                                                                              
  number of                                                                                                                              
  cargo ships                                                                                                                            
  in world                                                                                                                               
  fleet                                                                                                                                  

  Number of                                                                                                                              
  cargo ships                                                                                                                            

  Vessel                1                    2                    3A                  3B                  Grand Total                    
  Service                                                                                                                                

  CONTAINER             \-                   3                    58                  1,215               1,276                          

  RORO                  299                  283                  683                 621                 1,887                          

  TRANSPORT             1,746                1,779                4,791               16,916              25,232                         

  Grand Total           2,046                2,065                5,532               18,752              28,396                         

                        7%                   7%                   19%                 66%                                                

  Foreign                                                                                                                                
  emissions in                                                                                                                           
  U.S.                                                                                                                                   
  estimated by                                                                                                                           
  EPA Category                                                                                                                           

  Kg NOx per                                                                                                                             
  year                                                                                                                                   

  Vessel                1                    2                    3A                  3B                  Grand Total                    
  Service                                                                                                                                

  CONTAINER             \-                   14,629               277,960             5,851,788           6,144,378                      

  RORO                  1,441,355            1,363,020            3,290,049           2,992,378           9,086,803                      

  TRANSPORT             8,407,685            8,566,320            23,070,143          81,448,030          15,231,181                     

  Grand Total           9,849,040            9,943,970            26,638,152          90,292,196          136,723,359                    

                                                                                                                                         

  Without                                                                                                                                
  Category 1                                                                                                                             
  engines                                                                                                                                

  Kg NOx per                                                                                                                             
  year                                                                                                                                   

  Vessel                1                    2                    3A                  3B                  Grand Total                    
  Service                                                                                                                                

  CONTAINER                                  14,629               277,960             5,851,788           6,144,378                      

  RORO                                       1,363,020            3,290,049           2,992,378           7,645,448                      

  TRANSPORT                                  8,566,320            23,070,143          81,448,030          13,789,826                     

  Grand Total           \-                   9,943,970            26,638,152          90,292,196          126,874,319                    

                                                                                                                               93%       

  Note: There                                                                                                                            
  is a                                                                                                                                   
  potential                                                                                                                              
  error due to                                                                                                                           
  differences                                                                                                                            
  in emission                                                                                                                            
  rates for                                                                                                                              
  different                                                                                                                              
  engine types.                                                                                                                          
  This error                                                                                                                             
  (which would                                                                                                                           
  increase the                                                                                                                           
  estimates for                                                                                                                          
  Category 3                                                                                                                             
  engine                                                                                                                                 
  emissions and                                                                                                                          
  decrease the                                                                                                                           
  estimates for                                                                                                                          
  Category 2                                                                                                                             
  engine                                                                                                                                 
  emissions) is                                                                                                                          
  assumed to be                                                                                                                          
  offsetting                                                                                                                             
  and/or small                                                                                                                           
  because of                                                                                                                             
  the few                                                                                                                                
  numbers of                                                                                                                             
  category 1                                                                                                                             
  and 2 engines                                                                                                                          
  involved in                                                                                                                            
  cargo                                                                                                                                  
  transport.                                                                                                                             
  ------------- ------- ----------- ----- -- ----------- ----- -- ------------ --- -- ------------ -- --- ------------- -- --- ----- --- ------

  ----------------- --------- -- --------- -- ----------- -- ----------- --- ------------ ---- ------
  Estimated number                                                                             
  of cargo ships in                                                                            
  world fleet                                                                                  

  Number of cargo                                                                              
  ships                                                                                        

  Vessel Service    1            2            3A             3B              Grand Total       

  CONTAINER         \-           3            58             1,215           1,276             

  RORO              299          283          683            621             1,887             

  TRANSPORT         1,746        1,779        4,791          16,916          25,232            

  Grand Total       2,046        2,065        5,532          18,752          28,396            

                                                                                               

  Foreign emissions                                                                            
  in U.S. estimated                                                                            
  by EPA Category                                                                              

  Kg PM per year                                                                               

  Vessel Service    1            2            3A             3B              Grand Total       

  CONTAINER         \-           1,085        20,615         433,996         455,696           

  RORO              106,898      101,088      244,005        221,929         673,920           

  TRANSPORT         623,553      635,318      1,710,989      6,040,565       1,129,615         

  Grand Total       730,451      737,491      1,975,610      6,696,490       10,140,041        

                                                                                               

  Without Category                                                                             
  1 engines                                                                                    

  Kg PM per year                                                                               

  Vessel Service    1            2            3A             3B              Grand Total       

  CONTAINER                      1,085        20,615         433,996         455,696           

  RORO                           101,088      244,005        221,929         567,022           

  TRANSPORT                      635,318      1,710,989      6,040,565       1,022,718         

  Grand Total       \-           737,491      1,975,610      6,696,490       9,409,591         

                                                                                               

  Note: There is a                                                                             
  potential error                                                                              
  due to                                                                                       
  differences in                                                                               
  emission rates                                                                               
  for different                                                                                
  engine types.                                                                                
  This error (which                                                                            
  would increase                                                                               
  the estimates for                                                                            
  Category 3 engine                                                                            
  emissions and                                                                                
  decrease the                                                                                 
  estimates for                                                                                
  Category 2 engine                                                                            
  emissions) is                                                                                
  assumed to be                                                                                
  offsetting and/or                                                                            
  small because of                                                                             
  the few numbers                                                                              
  of category 1 and                                                                            
  2 engines                                                                                    
  involved in cargo                                                                            
  transport.                                                                                   
  ----------------- --------- -- --------- -- ----------- -- ----------- --- ------------ ---- ------

  ----------------- --------- -- --------- -- --------- -- ----------- --- ----------- ---- ------
  Estimated number                                                                          
  of cargo ships in                                                                         
  world fleet                                                                               

  Number of cargo                                                                           
  ships                                                                                     

  Vessel Service    1            2            3A           3B              Grand Total      

  CONTAINER         \-           3            58           1,215           1,276            

  RORO              299          283          683          621             1,887            

  TRANSPORT         1,746        1,779        4,791        16,916          25,232           

  Grand Total       2,046        2,065        5,532        18,752          28,396           

                                                                                            

  Foreign emissions                                                                         
  in U.S. estimated                                                                         
  by EPA Category                                                                           

  Kg HC per year                                                                            

  Vessel Service    1            2            3A           3B              Grand Total      

  CONTAINER         \-           446          8,471        178,333         187,249          

  RORO              43,925       41,538       100,264      91,192          276,919          

  TRANSPORT         256,223      261,058      703,060      2,482,120       464,169          

  Grand Total       300,148      303,041      811,795      2,751,645       4,166,630        

                                                                                            

  Without Category                                                                          
  1 engines                                                                                 

  Kg HC per year                                                                            

  Vessel Service    1            2            3A           3B              Grand Total      

  CONTAINER                      446          8,471        178,333         187,249          

  RORO                           41,538       100,264      91,192          232,994          

  TRANSPORT                      261,058      703,060      2,482,120       420,243          

  Grand Total       \-           303,041      811,795      2,751,645       3,866,481        
  ----------------- --------- -- --------- -- --------- -- ----------- --- ----------- ---- ------

Note: The potential error described on the previous worksheets does not
apply here because calculations for all engines use the same emission
factor for this pollutant.

  ----------------- --------- -- --------- -- ----------- -- ----------- --- ------------ ---- ------
  Estimated number                                                                             
  of cargo ships in                                                                            
  world fleet                                                                                  

  Number of cargo                                                                              
  ships                                                                                        

  Vessel Service    1            2            3A             3B              Grand Total       

  CONTAINER         \-           3            58             1,215           1,276             

  RORO              299          283          683            621             1,887             

  TRANSPORT         1,746        1,779        4,791          16,916          25,232            

  Grand Total       2,046        2,065        5,532          18,752          28,396            

                                                                                               

  Foreign emissions                                                                            
  in U.S. estimated                                                                            
  by EPA Category                                                                              

  Kg CO per year                                                                               

  Vessel Service    1            2            3A             3B              Grand Total       

  CONTAINER         \-           1,375        26,118         549,859         577,352           

  RORO              135,436      128,075      309,147        281,177         853,835           

  TRANSPORT         790,022      804,928      2,167,769      7,653,203       1,431,187         

  Grand Total       925,458      934,378      2,503,034      8,484,239       12,847,108        

                                                                                               

  Without Category                                                                             
  1 engines                                                                                    

  Kg CO per year                                                                               

  Vessel Service    1            2            3A             3B              Grand Total       

  CONTAINER                      1,375        26,118         549,859         577,352           

  RORO                           128,075      309,147        281,177         718,399           

  TRANSPORT                      804,928      2,167,769      7,653,203       1,295,751         

  Grand Total       \-           934,378      2,503,034      8,484,239       11,921,650        
  ----------------- --------- -- --------- -- ----------- -- ----------- --- ------------ ---- ------

Note: The potential error described on the previous worksheets does not
apply here because calculations for all engines use the same emission
factor for this pollutant.

Cargo Method emissions adjustments: Previous calculations are adjusted
to account for steam plants in U.S. fleet and to highlight Category 2
and 3 engines. See text for calculation details.

  -- ----------------------- ------------- ------------ ------------ ------------
     Region                  NOx           PM           HC           CO

     Oceangoing              113,638,624   9,248,696    3,283,404    10,123,828

     Categories 2 and 3 only 104,318,416   8,236,776    2,999,898    9,286,246

     US Cargo Ships all      9,835,758     800,502      284,188      876,247
     engines                                                         

     Diesel Engines          8,694,997     413,656      238,410      775,313

     Categories 2 and 3 only 7,993,121     397,158      216,735      704,826

     Steam Engines           1,140,761     386,846      45,778       100,934

     Foreign Vessels         103,802,866   8,448,194    2,999,215    9,247,581

     Categories 2 and 3 only 96,325,295    7,839,618    2,783,163    8,581,420

     Coastwise (domestic)    63,951,794    5,204,839    1,847,783    5,697,332

     Diesel Engines          56,534,599    2,689,578    1,550,134    5,041,063

     Categories 2 and 3 only 51,971,025    2,582,309    1,409,204    4,582,758

     Steam Engines           7,417,195     2,515,261    297,650      656,269

     Inland Rivers           126,518,467   6,395,253    4,509,931    13,905,622

     Categories 2 and 3 only 106,508,416   3,871,840    3,628,172    11,620,216

     US Cargo Ships all      94,498,878    4,776,727    3,368,547    10,386,355
     engines                                                         

     Diesel Engines          83,538,800    2,468,353    2,825,926    9,189,963

     Categories 2 and 3 only 76,795,399    2,369,907    2,569,009    8,354,464

     Steam Engines           10,960,078    2,308,374    542,622      1,196,392

     Foreign Vessels         32,019,589    1,618,526    1,141,384    3,519,267

     Categories 2 and 3 only 29,713,018    1,501,933    1,059,163    3,265,752

     Great Lakes             12,456,826    1,013,822    359,920      1,109,753

     Categories 2 and 3 only 10,227,034    534,656      278,795      902,570

     US Cargo Ships all      11,555,922    940,501      333,890      1,029,493
     engines                                                         

     Diesel Engines          10,215,654    486,000      280,105      910,907

     Categories 2 and 3 only 9,391,028     466,616      254,640      828,092

     Steam Engines           1,340,268     454,501      53,785       118,586

     Foreign Vessels         900,904       73,322       26,030       80,260

     Categories 2 and 3 only 836,006       68,040       24,155       74,478

     Total Nationwide        316,565,710   21,862,610   10,001,038   30,836,535
     Emissions                                                       

     Categories 2 and 3 only 273,024,892   15,225,581   8,316,069    26,391,791

     US Cargo Ships all      179,842,352   11,722,569   5,834,409    17,989,427
     engines                                                         

     Diesel Engines          158,984,050   6,057,587    4,894,574    15,917,246

     Categories 2 and 3 only 146,150,573   5,815,990    4,449,588    14,470,141

     Steam Engines           20,858,302    5,664,982    939,834      2,072,181

     Foreign Vessels         136,723,359   10,140,041   4,166,630    12,847,108

     Categories 2 and 3 only 126,874,319   9,409,591    3,866,481    11,921,650
  -- ----------------------- ------------- ------------ ------------ ------------

7.3 Engine Manufactures and Engine Models in the U.S. Flag

Table 16. Category 2 Engine Manufacturer Data, by Vessel Service

  --------------- ------------------ ------------ ----------- ------------
  Count of Engine                                 Category    

  Vessel Service  Engine Design      Engine       2           Grand Total

  CONTAINER       Alco               12V251C      1           1

                  Alco Total                      1           1

  CONTAINER Total                                             1
  --------------- ------------------ ------------ ----------- ------------

  --------------- ------------------ ------------ ----------- ------------
  Count of Engine                                 Category    

  Vessel Service  Engine Design      Engine       2           Grand Total

  FISHING         Alco               16V251F      2           2

                                     18V251F      2           2

                  Alco Total                      4           4

                  Caterpillar        3608TA       1           1

                                     3612TA       1           1

                  Caterpillar Total               2           2

                  Deutz              SBV6M628     1           1

                  Deutz Total                     1           1

                  Fairbanks, Morse   4-38D8-1/8   1           1

                  Fairbanks, Morse                            1
                  Total                                       

                  General Motors     12-567-BC    2           2

                                     12-645-E2    3           3

                                     12-645-E5    2           2

                                     12-645-E6    14          14

                                     16-567-BC    1           1

                                     16-645-E2    2           2

                                     16-645-E5    3           3

                                     16-645-E6    7           7

                                     16-645-E7B   1           1

                                     20-645-E5    2           2

                                     20-645-E6    1           1

                                     20-645-E7    18          18

                                     20-645-E7B   4           4

                                     8-645-E7B    2           2

                  General Motors                              62
                  Total                                       

                  MWM                TBD441V16    4           4

                  MWM Total                       4           4

  FISHING Total                                   74          74
  --------------- ------------------ ------------ ----------- ------------

  --------------- ------------------ ------------ ----------- ------------
  Count of Engine                                 Category    

  Vessel Service  Engine Design      Engine       2           Grand Total

  RORO            General Electric   7FDM12       3           3

                  General Electric                            3
                  Total                                       

                  General Motors     12-567-BC    1           1

                                     12-645-E6    3           3

                                     12-645-E7B   2           2

                                     16-645-E7B   2           2

                  General Motors                              8
                  Total                                       

  RORO Total                                      11          11
  --------------- ------------------ ------------ ----------- ------------

  --------------- ------------------ ------------- ----------- ------------
  Count of Engine                                  Category    

  Vessel Service  Engine Design      Engine        2           Grand Total

  TRANSPORT       Alco               12V251C       2           2

                                     12V251E       1           1

                                     16V251E       3           3

                                     16V251F       1           1

                  Alco Total                       7           7

                  Fairbanks, Morse   12-38TD-1/8   1           1

                  Fairbanks, Morse                             1
                  Total                                        

                  General Electric   7FDS16-A2     1           1

                  General Electric                             1
                  Total                                        

                  General Motors     12-645-E6     1           1

                                     16-645-E6     1           1

                                     16-645-E7     1           1

                                     20-645-E7     1           1

                                     8-645-E7      1           1

                  General Motors                               5
                  Total                                        

  TRANSPORT Total                                  14          14
  --------------- ------------------ ------------- ----------- ------------

  --------------- ------------------ ------------- ----------- ------------
  Count of Engine                                  Category    

  Vessel Service  Engine Design      Engine        2           Grand Total

  TUG             Alco               12V251C       8           8

                                     12V251E       17          17

                                     12V251F       10          10

                                     16V251E       8           8

                                     16V251F       6           6

                                     18V251F       3           3

                  Alco Total                       52          52

                  Caterpillar        3608TA        2           2

                  Caterpillar Total                2           2

                  Fairbanks, Morse   10-38D8-1/8   1           1

                                     12-38D8-1/8   1           1

                                     12-38TD-1/8   1           1

                                     8-38D8-1/8    1           1

                  Fairbanks, Morse                             4
                  Total                                        

                  General Electric   7FDM16        1           1

                  General Electric                             1
                  Total                                        

                  General Motors     12-567-BC     4           4

                                     12-645-C      3           3

                                     12-645-E2     6           6

                                     12-645-E5     4           4

                                     12-645-E6     66          66

                                     12-645-E7     1           1

                                     12-645-E7A    1           1

                                     12-645-E7B    22          22

                                     12-645-F7B    2           2

                                     12V-645-E6    1           1

                                     16-567-BC     23          23

                                     16-645        3           3

                                     16-645-C      1           1

                                     16-645-E2     13          13

                                     16-645-E3     2           2

                                     16-645-E5     15          15

                                     16-645-E6     67          67

                                     16-645-E7     33          33

                                     16-645-E7B    17          17

                                     16-645-E8     4           4

                                     16-645-F7B    4           4

                                     16-710-GA     2           2

                                     20-645-E5     7           7

                                     20-645-E7     3           3

                                     20-645-E7B    18          18

                                     8-645-E2      1           1

                                     8-645-E5      1           1

                                     8-645-E6      4           4

                  General Motors                               328
                  Total                                        

                  MWM                TBD441V16     1           1

                  MWM Total                        1           1

                  Niigata            6L25BX        1           1

                  Niigata Total                    1           1

                  Wartsila           12V22         1           1

                                     8R22          1           1

                  Wartsila Total                   2           2

  TUG Total                                        391         391
  --------------- ------------------ ------------- ----------- ------------

  --------------- ------------------ ------------- ----------- ------------
  Count of Engine                                  Category    

  Vessel Service  Engine Design      Engine        2           Grand Total

  UTILITY         Alco               12V251E       3           3

                                     12V251F       1           1

                                     16V251F       1           1

                                     18V251F       1           1

                  Alco Total                       6           6

                  Caterpillar        3608TA        2           2

                                     3612TA        1           1

                  Caterpillar Total                3           3

                  Fairbanks, Morse   12-38TD-1/8   1           1

                  Fairbanks, Morse                             1
                  Total                                        

                  General Motors     12-567-BC     7           7

                                     12-645-C      1           1

                                     12-645-E2     10          10

                                     12-645-E6     25          25

                                     12-645-E7     1           1

                                     12-645-E7A    6           6

                                     12-645-E7B    2           2

                                     12-645-F7B    1           1

                                     16-645-E2     3           3

                                     16-645-E5     6           6

                                     16-645-E6     13          13

                                     16-645-E7     2           2

                                     16-645-E7B    5           5

                                     16-645-E8     1           1

                                     16-645-F7B    1           1

                                     8-645-E6      3           3

                  General Motors                               87
                  Total                                        

                  MAN                6L20/27       1           1

                  MAN Total                        1           1

  UTILITY Total                                    98          98
  --------------- ------------------ ------------- ----------- ------------

Table 17. Category 3A and 3B Engine Manufacturer Data, by Vessel Service

  ------------- ---------------- ----------- ---------- ---------- ----------
  Count of                                   Category              
  Engine                                                           

  Vessel        Engine Design    Engine      3A         3B         Grand
  Service                                                          Total

  CONTAINER     B&W              12L90GFCA              2          2

                                 7L70MC                 3          3

                                 8L80MC                 1          1

                                 8L90GBE                2          2

                                 9L80MCE                4          4

                B&W Total                               12         12

                Sulzer           12RND90M               5          5

                                 12RTA84                5          5

                                 6RND90                 1          1

                                 6RTA76                 2          2

                                 7RLB90                 9          9

                                 7RTA76                 3          3

                                 9RND90                 3          3

                                 9RND90M                7          7

                Sulzer Total                            35         35

  CONTAINER                                                        47
  Total                                                            
  ------------- ---------------- ----------- ---------- ---------- ----------

  ------------- ---------------- ------------ ---------- ---------- ----------
  Count of                                    Category              
  Engine                                                            

  Vessel        Engine Design    Engine       3A         3B         Grand
  Service                                                           Total

  FISHING       MaK              6M453C                  1          1

                                 6M551AK                 1          1

                                 8M453C                  1          1

                                 8M551AK                 1          1

                                 9M453AK                 4          4

                                 9M453C                  1          1

                MaK Total                                9          9

                Mitsubishi       8UET45/80D              1          1

                Mitsubishi Total                                    1

                Wartsila         12V32E       1                     1

                                 6R32         1                     1

                Wartsila Total                2                     2

  FISHING Total                               2          10         12
  ------------- ---------------- ------------ ---------- ---------- ----------

  ------------- ---------------- ------------ ---------- ---------- ----------
  Count of                                    Category              
  Engine                                                            

  Vessel        Engine Design    Engine       3A         3B         Grand
  Service                                                           Total

  PASSENGER     Enterprise       DMRV-16-4               1          1

                Enterprise Total                                    1

                MWM              TBD604-B12   1                     1

                MWM Total                     1                     1

                Sulzer           6TD48                   1          1

                Sulzer Total                             1          1

  PASSENGER                                              1          2
  Total                                                             
  ------------- ---------------- ------------ ---------- ---------- ----------

  ------------- ---------------- ------------ ---------- ---------- ----------
  Count of                                    Category              
  Engine                                                            

  Vessel        Engine Design    Engine       3A         3B         Grand
  Service                                                           Total

  RORO          B&W              12L90GFCA               1          1

                                 6K90GF                  1          1

                                 6L60MC                  1          1

                                 6L70MC                  1          1

                                 6S60MCE                 1          1

                                 9K906F                  1          1

                                 9K90GF                  1          1

                B&W Total                                7          7

                Pielstick        18PC2V-400   8                     8

                Pielstick Total               8                     8

                Sulzer           6RND90                  2          2

                                 6RTA62                  1          1

                                 8RND90M                 2          2

                                 9RND90                  1          1

                Sulzer Total                             6          6

  RORO Total                                  8          13         21
  ------------- ---------------- ------------ ---------- ---------- ----------

  ------------- ---------------- -------------- ---------- ---------- ----------
  Count of                                      Category              
  Engine                                                              

  Vessel        Engine Design    Engine         3A         3B         Grand
  Service                                                             Total

  TRANSPORT     B&W              10K84EF                   1          1

                                 4L80MC                    2          2

                                 4L90GBE                   2          2

                                 8K90GF                    1          1

                                 Not specified             1          1

                B&W Total                                  7          7

                Enterprise       DMRV-12-4                 3          3

                                 DMRV16-4                  1          1

                Enterprise Total                                      4

                MaK              6M453AK                   1          1

                                 6M601AK                   1          1

                                 8M453AK                   1          1

                                 8M601AK                   2          2

                MaK Total                                  5          5

                Pielstick        12PC2V-400     1                     1

                                 14PC2-2V-400   4                     4

                                 16PC2V-400     5                     5

                                 18PC2-5V-400   2                     2

                Pielstick Total                 12                    12

                Sulzer           5RTA76                    5          5

                                 7RTA58                    1          1

                                 8RTA84                    2          2

                                 9RND90                    2          2

                Sulzer Total                               10         10

                Wartsila         8R46                      1          1

                Wartsila Total                             1          1

  TRANSPORT                                                12         27
  Total                                                               
  ------------- ---------------- -------------- ---------- ---------- ----------

  ------------- ---------------- -------------- ---------- ---------- ----------
  Count of                                      Category              
  Engine                                                              

  Vessel        Engine Design    Engine         3A         3B         Grand
  Service                                                             Total

  TUG           B&W              7S28LU         2                     2

                B&W Total                       2                     2

                Enterprise       DMRV-16-4                 6          6

                Enterprise Total                                      6

                MaK              6M551AK                   2          2

                MaK Total                                  2          2

                Pielstick        14PC2-2V-400   2                     2

                                 14PC2-5V-400   2                     2

                                 14PC2V-400     1                     1

                Pielstick Total                 5                     5

                Wartsila         6R32           2                     2

                Wartsila Total                  2                     2

  TUG Total                                     9          8          17
  ------------- ---------------- -------------- ---------- ---------- ----------

  ------------- ---------------- ----------- ---------- ---------- ----------
  Count of                                   Category              
  Engine                                                           

  Vessel        Engine Design    Engine      3A         3B         Grand
  Service                                                          Total

  UTILITY       Cooper Bessemer  KSV16T      1                     1

                Cooper Bessemer                         1          
                Total                                              

                Daihatsu         8DSM-32     2                     2

                Daihatsu Total               2                     2

                Enterprise       DMRV-16-4              1          1

                Enterprise Total                                   1

                MaK              6M453AK                1          1

                MaK Total                               1          1

                Nordberg         32112                  1          1

                Nordberg Total                                     1

                Wartsila         9R32D       1                     1

                Wartsila Total               1                     1

  UTILITY Total                              4          3          7
  ------------- ---------------- ----------- ---------- ---------- ----------

Table 18. Un-categorized Engine Manufacturer Data, by Vessel Service

  -------------- ----------------- ------------ ---------------- -------------
  Count of                                      Category         
  Engine                                                         

  Vessel Service Engine Design     Engine       Un-categorized   Grand Total

  CONTAINER      MAN               K9Z78/155E   2                2

                 MAN Total                      2                2

                 Not specified     Not                           
                                   specified                     

                 Not specified                                   
                 Total                                           

  CONTAINER                                     2                2
  Total                                                          
  -------------- ----------------- ------------ ---------------- -------------

  -------------- ----------------- ------------ ---------------- -------------
  Count of                                      Category         
  Engine                                                         

  Vessel Service Engine Design     Engine       Un-categorized   Grand Total

  FISHING        \....             Not          1071             1071
                                   specified                     

                 \.... Total                    1071             1071

                 Akasaka           AH38         1                1

                                   TM6SS        1                1

                                   UZ6SS        1                1

                                   Not          1                1
                                   specified                     

                 Akasaka Total                  4                4

                 Alco              Not          2                2
                                   specified                     

                 Alco Total                     2                2

                 Alpha             10V23L-VO    1                1

                                   406-24VO     1                1

                                   6L28/32      1                1

                                   8V23L-VO     1                1

                                   Not          3                3
                                   specified                     

                 Alpha Total                    7                7

                 B&W               6-33MTF-60   1                1

                 B&W Total                      1                1

                 Brons             12TD200      1                1

                 Brons Total                    1                1

                 Buda              Not          1                1
                                   specified                     

                 Buda Total                     1                1

                 Caterpillar       Not          194              194
                                   specified                     

                 Caterpillar Total                               194

                 Cooper Bessemer   Not          4                4
                                   specified                     

                 Cooper Bessemer                                 4
                 Total                                           

                 Cummins           Not          26               26
                                   specified                     

                 Cummins Total                                   26

                 Deutz             Not          3                3
                                   specified                     

                 Deutz Total                    3                3

                 Enterprise        Not          12               12
                                   specified                     

                 Enterprise Total                                12

                 Fairbanks, Morse  Not          11               11
                                   specified                     

                 Fairbanks, Morse                                11
                 Total                                           

                 General Electric  Not          3                3
                                   specified                     

                 General Electric                                3
                 Total                                           

                 General Motors    Not          138              138
                                   specified                     

                 General Motors                                  138
                 Total                                           

                 Gray              Not          1                1
                                   specified                     

                 Gray Total                     1                1

                 Kromhout          8F/SW240     1                1

                 Kromhout Total                                  1

                 MaK               9M452AK      1                1

                                   Not          1                1
                                   specified                     

                 MaK Total                      2                2

                 MAN               Not                           
                                   specified                     

                 MAN Total                                       

                 Niigata           Not          1                1
                                   specified                     

                 Niigata Total                  1                1

                 Nohab             Not                           
                                   specified                     

                 Nohab Total                                     

                 Nordberg          Not          2                2
                                   specified                     

                 Nordberg Total                                  2

                 Normo             BRM-8        2                2

                                   BRM-9        1                1

                                   KRMB-9       1                1

                                   KVMB-12      2                2

                                   KVMB-18      1                1

                                   Not          1                1
                                   specified                     

                 Normo Total                    8                8

                 Penta             TAMD120B     1                1

                 Penta Total                    1                1

                 Polar             F216V-A      2                2

                                   F216V-B      2                2

                 Polar Total                    4                4

                 Not specified     Not                           
                                   specified                     

                 Not specified                                   
                 Total                                           

                 Not specified     Not          249              249
                                   specified                     

                 Not specified                                   249
                 Total                                           

                 Stork             Not          1                1
                                   specified                     

                 Stork Total                    1                1

                 Stork-Werkspoor   16SW280      1                1

                 Stork-Werkspoor                                 1
                 Total                                           

                 Wartsila          Not                           
                                   specified                     

                 Wartsila Total                                  

                 Westinghouse      Not          1                1
                                   specified                     

                 Westinghouse                                    1
                 Total                                           

                 White Superior    Not          1                1
                                   specified                     

                 White Superior                                  1
                 Total                                           

                 Wichmann          10V28A       1                1

                                   4AXA         2                2

                                   Not          2                2
                                   specified                     

                 Wichmann Total                                  5

  FISHING Total                                 1756             1756
  -------------- ----------------- ------------ ---------------- -------------

  -------------- ----------------- ------------ ---------------- -------------
  Count of                                      Category         
  Engine                                                         

  Vessel Service Engine Design     Engine       Un-categorized   Grand Total

  PASSENGER      \....             Not          1                1
                                   specified                     

                 \.... Total                    1                1

                 Baudouin          Not          1                1
                                   specified                     

                 Baudouin Total                                  1

                 Caterpillar       Not          1                1
                                   specified                     

                 Caterpillar Total                               1

                 De Laval          Not                           
                                   specified                     

                 De Laval Total                                  

                 Enterprise        Not          2                2
                                   specified                     

                 Enterprise Total                                2

                 Fairbanks, Morse  Not          1                1
                                   specified                     

                 Fairbanks, Morse                                1
                 Total                                           

                 General Electric  Not                           
                                   specified                     

                 General Electric                                
                 Total                                           

                 General Motors    Not          3                3
                                   specified                     

                 General Motors                                  3
                 Total                                           

                 MaK               Not                           
                                   specified                     

                 MaK Total                                       

                 Not specified     Not          2                2
                                   specified                     

                 Not specified                                   2
                 Total                                           

  PASSENGER                                     11               11
  Total                                                          
  -------------- ----------------- ------------ ---------------- -------------

  -------------- ----------------- ------------ ---------------- -------------
  Count of                                      Category         
  Engine                                                         

  Vessel Service Engine Design     Engine       Un-categorized   Grand Total

  RORO           Busch-Sulzer      Not          1                1
                                   specified                     

                 Busch-Sulzer                                    1
                 Total                                           

                 Caterpillar       Not          1                1
                                   specified                     

                 Caterpillar Total                               1

                 Cooper Bessemer   Not          1                1
                                   specified                     

                 Cooper Bessemer                                 1
                 Total                                           

                 Fairbanks, Morse  Not          3                3
                                   specified                     

                 Fairbanks, Morse                                3
                 Total                                           

                 General Electric  Not          3                3
                                   specified                     

                 General Electric                                3
                 Total                                           

                 General Motors    Not          1                1
                                   specified                     

                 General Motors                                  1
                 Total                                           

                 MAN               14V52/55A    3                3

                                   9L52/55A     3                3

                 MAN Total                      6                6

                 Not specified     Not                           
                                   specified                     

                 Not specified                                   
                 Total                                           

                 Stork-Werkspoor   6TM620       2                2

                 Stork-Werkspoor                                 2
                 Total                                           

                 Sulzer            6RLB66       2                2

                                   6RND68       1                1

                                   6RND68M      2                2

                                   7RND76M      5                5

                 Sulzer Total                   10               10

                 Werkspoor         18TM410      5                5

                 Werkspoor Total                                 5

  RORO Total                                    33               33
  -------------- ----------------- ------------ ---------------- -------------

  -------------- ----------------- --------------- ---------------- -------------
  Count of                                         Category         
  Engine                                                            

  Vessel Service Engine Design     Engine          Un-categorized   Grand Total

  TRANSPORT      \....             Not specified   14               14

                 \.... Total                       14               14

                 B&W               6K67GF          2                2

                                   7K67GF          1                1

                                   8K45GF          2                2

                                   9-84VT2BF-180   1                1

                 B&W Total                         6                6

                 Busch-Sulzer      Not specified   1                1

                 Busch-Sulzer                                       1
                 Total                                              

                 Caterpillar       Not specified   5                5

                 Caterpillar Total                                  5

                 Cooper Bessemer   Not specified   3                3

                 Cooper Bessemer                                    3
                 Total                                              

                 Deutz             Not specified   1                1

                 Deutz Total                       1                1

                 Enterprise        Not specified   1                1

                 Enterprise Total                                   1

                 Fairbanks, Morse  Not specified   7                7

                 Fairbanks, Morse                                   7
                 Total                                              

                 General Motors    Not specified   11               11

                 General Motors                                     11
                 Total                                              

                 Gray              Not specified   1                1

                 Gray Total                        1                1

                 Hamilton          Not specified   1                1

                 Hamilton Total                                     1

                 Kromhout          9FCHD240        1                1

                 Kromhout Total                                     1

                 MaK               6M451AK         1                1

                                   Not specified   1                1

                 MaK Total                         2                2

                 MAN               9L52/55B        1                1

                 MAN Total                         1                1

                 Nordberg          Not specified   3                3

                 Nordberg Total                                     3

                 Rathbun-Jones     Not specified   1                1

                 Rathbun-Jones                                      1
                 Total                                              

                 Smit-Bolnes       307HD           1                1

                 Smit-Bolnes Total                                  1

                 Sulzer            5RLA90          1                1

                                   5RLB90          5                5

                                   5RND76M         5                5

                                   6RND76M         2                2

                                   7RND68          1                1

                                   7RND76          2                2

                 Sulzer Total                      16               16

                 Wichmann          Not specified   1                1

                 Wichmann Total                                     1

                 Winton            Not specified   1                1

                 Winton Total                      1                1

  TRANSPORT                                                         78
  Total                                                             
  -------------- ----------------- --------------- ---------------- -------------

  -------------- ----------------- ------------ ---------------- -------------
  Count of                                      Category         
  Engine                                                         

  Vessel Service Engine Design     Engine       Un-categorized   Grand Total

  TUG            \....             Not          84               84
                                   specified                     

                 \.... Total                    84               84

                 Alco              Not          2                2
                                   specified                     

                 Alco Total                     2                2

                 Alpha             12V23L-VO    1                1

                                   14V23L-VO    2                2

                 Alpha Total                    3                3

                 B&W               7L67GFCA     1                1

                 B&W Total                      1                1

                 Bolnes            Not          1                1
                                   specified                     

                 Bolnes Total                   1                1

                 Brons             12GV-H       1                1

                                   Not          2                2
                                   specified                     

                 Brons Total                    3                3

                 Caterpillar       Not          77               77
                                   specified                     

                 Caterpillar Total                               77

                 Cooper Bessemer   Not          2                2
                                   specified                     

                 Cooper Bessemer                                 2
                 Total                                           

                 Crepelle          6SN3         1                1

                 Crepelle Total                 1                1

                 Cummins           Not          1                1
                                   specified                     

                 Cummins Total                                   1

                 Enterprise        Not          12               12
                                   specified                     

                 Enterprise Total                                12

                 Fairbanks, Morse  Not          49               49
                                   specified                     

                 Fairbanks, Morse                                49
                 Total                                           

                 General Electric  Not          1                1
                                   specified                     

                 General Electric                                1
                 Total                                           

                 General Motors    Not          323              323
                                   specified                     

                 General Motors                                  323
                 Total                                           

                 Imperial          Not          1                1
                                   specified                     

                 Imperial Total                 1                1

                 Kromhout          Not          2                2
                                   specified                     

                 Kromhout Total                                  2

                 MaK               Not          1                1
                                   specified                     

                 MaK Total                      1                1

                 Mirrlees          Not          2                2
                                   specified                     

                 Mirrlees Total                 2                2

                 Nohab             F25.8V       1                1

                                   Not          4                4
                                   specified                     

                 Nohab Total                    5                5

                 Nordberg          Not          4                4
                                   specified                     

                 Nordberg Total                                  4

                 Polar             F212V        1                1

                                   F212V-D      1                1

                                   F28V-B       3                3

                                   F28V-D       2                2

                                   SF16RS-C     1                1

                                   SF18VS-F     1                1

                                   Not          5                5
                                   specified                     

                 Polar Total                    14               14

                 Not specified     Not          11               11
                                   specified                     

                 Not specified                                   11
                 Total                                           

                 Rathbun-Jones     Not          1                1
                                   specified                     

                 Rathbun-Jones                                   1
                 Total                                           

                 Skinner Unaflow   Not          1                1
                                   specified                     

                 Skinner Unaflow                                 1
                 Total                                           

                 Stork             Not          1                1
                                   specified                     

                 Stork Total                    1                1

                 Stork-Werkspoor   Not          1                1
                                   specified                     

                 Stork-Werkspoor                                 1
                 Total                                           

                 Sulzer            Not          1                1
                                   specified                     

                 Sulzer Total                   1                1

                 Waukesha          Not          1                1
                                   specified                     

                 Waukesha Total                                  1

                 Westinghouse      Not          1                1
                                   specified                     

                 Westinghouse                                    1
                 Total                                           

                 White Superior    Not          3                3
                                   specified                     

                 White Superior                                  3
                 Total                                           

                 Wichmann          10AXAG       1                1

                                   5AXA         2                2

                 Wichmann Total                                  3

                 Winton            Not          1                1
                                   specified                     

                 Winton Total                   1                1

  TUG Total                                     614              614
  -------------- ----------------- ------------ ---------------- -------------

  -------------- ----------------- ------------ ---------------- -------------
  Count of                                      Category         
  Engine                                                         

  Vessel Service Engine Design     Engine       Un-categorized   Grand Total

  UTILITY        \....             Not          51               51
                                   specified                     

                 \.... Total                    51               51

                 Alco              Not          1                1
                                   specified                     

                 Alco Total                     1                1

                 Alpha             6SL28L-VO    1                1

                 Alpha Total                    1                1

                 B&W               8-35VBF-62   1                1

                 B&W Total                      1                1

                 Caterpillar       Not          72               72
                                   specified                     

                 Caterpillar Total                               72

                 Cooper Bessemer   Not          1                1
                                   specified                     

                 Cooper Bessemer                                 1
                 Total                                           

                 Cummins           Not          3                3
                                   specified                     

                 Cummins Total                                   3

                 De Laval          Not          1                1
                                   specified                     

                 De Laval Total                 1                1

                 Deutz             Not          2                2
                                   specified                     

                 Deutz Total                    2                2

                 Enterprise        Not          3                3
                                   specified                     

                 Enterprise Total                                3

                 Fairbanks, Morse  Not          8                8
                                   specified                     

                 Fairbanks, Morse                                8
                 Total                                           

                 Fiat              Not          1                1
                                   specified                     

                 Fiat Total                     1                1

                 General Motors    Not          71               71
                                   specified                     

                 General Motors                                  71
                 Total                                           

                 Kromhout          8F/SW240     1                1

                                   9F/SW240     3                3

                                   Not          2                2
                                   specified                     

                 Kromhout Total                                  6

                 Lugger            L6125A       1                1

                 Lugger Total                   1                1

                 M.T.U.            Not                           
                                   specified                     

                 M.T.U. Total                                    

                 MAN               Not          1                1
                                   specified                     

                 MAN Total                      1                1

                 Mitsubishi        Not          1                1
                                   specified                     

                 Mitsubishi Total                                1

                 Nohab             F26R         1                1

                                   Not          1                1
                                   specified                     

                 Nohab Total                    2                2

                 Nordberg          Not          4                4
                                   specified                     

                 Nordberg Total                                  4

                 Polar             F26R-A       1                1

                                   F26R-B       1                1

                                   F26R-D       2                2

                                   SF16RS-D     1                1

                                   SF16RS-F     2                2

                                   Not          1                1
                                   specified                     

                 Polar Total                    8                8

                 Not specified     Not                           
                                   specified                     

                 Not specified                                   
                 Total                                           

                 Not specified     Not          5                5
                                   specified                     

                 Not specified                                   5
                 Total                                           

                 Stork             Not          2                2
                                   specified                     

                 Stork Total                    2                2

                 Stork-Werkspoor   8SW280       1                1

                 Stork-Werkspoor                                 1
                 Total                                           

                 Waukesha          Not          1                1
                                   specified                     

                 Waukesha Total                                  1

                 Werkspoor         6TM410       1                1

                                   9TM410       1                1

                 Werkspoor Total                                 2

                 White Superior    Not          1                1
                                   specified                     

                 White Superior                                  1
                 Total                                           

                 Wichmann          4AXA         2                2

                                   5AXA         1                1

                 Wichmann Total                                  3

  UTILITY Total                                 254              254
  -------------- ----------------- ------------ ---------------- -------------

[^1]: EPA is developing a marine module for its NONROAD emissions model
    that may ultimately provide such a comprehensive estimate.

[^2]: This is without including the U.S. flag container ships, of which
    only three ships out of 87 were in the unassigned category; a
    chi-squared test for the world fleet -- including container ships --
    showed similar results.

[^3]: This analysis estimates that less than 2% of the world fleet of
    passenger ships are propelled by EPA Category 2 and/or 3 CI marine
    engines. There are far more passenger ferries than passenger cruise
    ships in the world fleet.