Marine Fuel Choice for OceanGoing Vessels within Emissions 

Control Areas

June 2015

Independent Statistics & Analysis

www.eia.gov

U.S. Department of Energy

Washington, DC 20585
U.S. Energy Information Administration | Marine fuel choice for ocean going vessels within emissions control areas i

This report was prepared by the U.S. Energy Information Administration (EIA), the statistical and 

analytical agency within the U.S. Department of Energy. By law, EIA’s data, analyses, and forecasts are 

independent of approval by any other officer or employee of the United States Government. The views 

in this report therefore should not be construed as representing those of the Department of Energy or 

other Federal agencies.
June 2015

U.S. Energy Information Administration | Marine fuel choice for ocean going vessels within emissions control areas 1

Introduction

The U.S. Energy Information Administration (EIA) contracted with Leidos Corporation to analyze the 

impact on ocean-going vessel fuel usage of the International Convention for the Prevention of Pollution 

from Ships (MARPOL) emissions control areas in North America and the Caribbean.

Leidos developed a new methodology for calculating fuel consumption by ocean-going maritime vessels 

in the United States within emission control areas by:

• Establishing a fuel usage methodology baseline for ocean-going vessels by U.S. Census Division 

and Puerto Rico for several ship types and energy and non-energy commodities

• Discussing relevant MARPOL and associated U.S. Environmental Protection Agency emissions 

regulations and major emissions compliance strategies, including exhaust scrubber controls, fuel 

switching to liquefied natural gas, and engine-based controls

• Creating a methodology for projecting ocean-going vessel travel demand by commodity and ship 

type, ship efficiency, and fuel choice by various compliance choices

In addition, Leidos recommended study of additional issues for future model improvements as more 

data become available. These include:

• Expanding the scope of the marine fuel estimates to include travel beyond North American and 

Caribbean emission control areas and Great Lakes and inland waterway transit

• Expanding the scope to include fuel usage estimates tied to U.S. ports for tugs, barges, and 

lightering vessels, fishing vessels, cruise ships, and other commercial vessels

• Fractioning the fuel purchases made in the United States versus abroad

• Improving the future projections of fuel usage, including slow steaming and auxiliary power 

needs, and technology adoption

EIA plans to update the upcoming Annual Energy Outlook 2016 to include a new methodology for 

calculating the amount of fuel consumption by ocean-going vessels traveling though North American 

and Caribbean emissions control areas, including the impact of compliance strategies. Further, EIA plans 

to update the methodology for calculating ocean going vessel energy demand to include estimation of 

fuel consumption by ship type and commodity moved. The new methodology will also estimate energy 

consumption within and outside emission control areas. In addition, EIA will explore the interplay 

between refinery operation, refined product slates, and marine fuels in light of the impact of emission 

regulations.
June 2015

U.S. Energy Information Administration | Marine fuel choice for ocean going vessels within emissions control areas 2

Appendix A
Marine Fuel Choice

for Ocean Going Vessels within 

Emission Control Areas

EIA Task 7965, Subtask 17

Prepared for:

Energy Information Administration

Office of Energy Analysis

Office of Energy Consumption and Efficiency Analysis

Prepared by: 

Leidos Corporation

Steve O’Malley, Ken Walsh, Adam Hasen, Delma Bratvold, 

and Jay Ratafia-Brown

FINAL REPORT

April 2015
i

Disclaimer

Certain statements included in this report constitute forward-looking statements. The 

achievement of certain results or other expectations contained in such forward-looking 

statements involve known and unknown risks, uncertainties and other factors which may cause 

actual results, performance or achievements described in the report to be materially different 

from any future results, performance or achievements expressed or implied by such forwardlooking statements. We do not plan to issue any updates or revisions to the forward-looking 

statements if or when our expectations or events, conditions, or circumstances on which such 

statements are based occur.
ii

Table of Contents

List of Tables .................................................................................................................................iii

List of Figures................................................................................................................................ iv

List of Abbreviations and Acronyms.............................................................................................. v

Executive Summary...................................................................................................................... vii

1 Introduction............................................................................................................................. 1

2 Baseline Current Estimates..................................................................................................... 2

2.1 Grouping the Ships........................................................................................................... 3

2.2 Determining Engine Size and Design Speed of Each Ship Grouping.............................. 5

2.3 Calculating Fuel Oil Consumption................................................................................... 8

2.3.1 Time ship will be operating in the ECA ................................................................... 9

2.3.2 Power consumption in propelling the ships through the ECA................................ 11

2.3.3 Auxiliary power consumption................................................................................. 11

2.3.4 Fuel consumed in 2012 ........................................................................................... 13

2.4 Distribution Between Energy and Non-Energy Products .............................................. 15

2.4.1 Determining percentage of tankers and dry bulk ships transporting energy products 

15

2.4.2 Determining number of gas carriers (ships) that are transporting LNG and LPG.. 16

3 Compliance Strategies .......................................................................................................... 19

3.1 Regulatory Framework................................................................................................... 19

3.1.1 U.S. EPA regulations.............................................................................................. 19

3.1.2 IMO protocols......................................................................................................... 21

3.2 Major Compliance Strategies......................................................................................... 22

3.2.1 Strategy A – Exhaust Controls................................................................................ 22

3.2.2 Strategy B – LNG-fueled vessels............................................................................ 26

3.2.3 Strategy C – Engine-based controls........................................................................ 27

3.3 Other Compliance Options Considered.......................................................................... 28

3.4 Compliance Cost Issues ................................................................................................. 29

4 Projections to Future Years................................................................................................... 31

4.1 Increased Efficiency of New Vessels............................................................................. 31

4.2 Changes in Shipping Demands ...................................................................................... 32

4.3 Compliance Choices....................................................................................................... 36

4.4 Fuel Estimates................................................................................................................ 40

5 Recommendations................................................................................................................. 42

Appendix A. Matrix-Based Derivations of Baseline Estimates.................................................... 45

Appendix B. Ship Routes to Avoid Significant Travel in North American ECA ........................ 47

Appendix C. Adoption of Compliance Strategies by Ship Industry............................................. 48

Appendix D. Computation of Port Times..................................................................................... 55
iii

List of Tables

Table 2-1. Estimating Average DWT of Tanker Ships Operating in the Pacific ........................... 3

Table 2-2. Ship Engine Output for Each Ship Profile .................................................................... 6

Table 2-3. Ship Design Speed for Each Ship Profile...................................................................... 6

Table 2-4. Slow Speed Steaming Reduction in Ship Speed by Vessel Type ................................. 7

Table 2-5. Slow Speed Steaming Reduction in Ship Power Output by Vessel Type..................... 8

Table 2-6. Fuel Oil Consumption Rates for Slow, Medium and High Speed Diesel Engines ....... 8

Table 2-7. Power Spent for Propulsion through the ECA ............................................................ 11

Table 2-8. Auxiliary Power Spent in ECA and Port..................................................................... 12

Table 2-9. Fuel Oil Consumption Rates for Auxiliary Power ...................................................... 12

Table 2-10. Total Fuel Consumed in 2012 for Transit and Auxiliary Power............................... 13

Table 2-11. Percentage of Product Moved on Tank Ships That are Energy Products (top). 

Percentage of Product Moved on Dry Bulk Ships that are Energy Products (bottom)................. 16

Table 2-12. LNG Carriers as a Percentage of Total Gas Carriers ................................................ 17

Table 2-13. Total Fuel Consumed in 2012 by Vessel Type and Subtype..................................... 18

Table 3-1. Marine Engine Categories........................................................................................... 19

Table 3-2. MARPOL Annex VI NOx Emission Standards........................................................... 20

Table 3-3. MARPOL Annex VI Fuel Sulfur Limits Globally and Within a SOx ECA................ 22

Table 4-1. ICCT List of Potential Fuel Reduction Technologies................................................. 32

Table 4-2. Weight Transported in 2012 Through U.S. Waters Now under the North American 

ECA............................................................................................................................................... 33

Table 4-3. Energy Commodity Changes in the AEO 2014 Reference Case ................................ 33

Table 4-4. Potential NEMS Variables That Could Indicate Fleet Growth in Future Years ......... 34

Table 4-5. Fleet Profiles of Compliance Strategies under Three Scenarios................................. 39

Table 4-6. Total Fuel Consumed in North American and U.S. Caribbean ECAs in 2021 by 

Marine Fuel Type.......................................................................................................................... 40

Table 4-7. Total Fuel Consumed in North American and U.S. Caribbean ECAs in 2021 by 

NEMS Fuel Type .......................................................................................................................... 41

Table 5-1. Model Inputs for a Possible Technology Adoption Model for Fuel Use Projections . 44
iv

List of Figures

Figure ES- 1. Total 2012 Fuel Consumed by OGVs within ECAs by U.S. Census Divisions 

Based on Vessel Type.................................................................................................................. viii

Figure ES- 3. Sample Projections of Fuel Consumed within North American and U.S. Caribbean 

ECAs by NEMS Fuel Type............................................................................................................ ix

Figure 2-1. Total Fuel Consumed in 2012 by Ship Type in Census Divisions That Have Seaports

......................................................................................................................................................... 3

Figure 2-3. Average DWT of Each Vessel Type by Census Division............................................ 5

Figure 2-4. Most Common Ship Bunker Fuels............................................................................... 9

Figure 2-5. Time Each Vessel Type Operated in the ECA Waters in 2012 ................................. 10

Figure 2-7. Fuel Consumption in ECA Waters in 2012................................................................ 14
v

List of Abbreviations and Acronyms

ACOE Army Corps of Engineers

AEO Annual Energy Outlook

Btu British thermal units

CWA U.S. Clean Water Act

CO2 carbon dioxide

dwt dead weight tonnage

C1, C2, & C3 Category 1, 2, and 3 (marine diesel engines)

dm3cubic decimeter (liter)

DNV Det Norske Veritas

ECA Emission Control Area

EEZ exclusive economic zone

EGCS exhaust gas cleaning system

EGR exhaust gas recirculation

EIA Energy Information Administration

EPA U.S. Environmental Protection Agency

EU European Union

GHG greenhouse gas

GWh Gigawatt-hours

HAM humid air motor

HFO heavy fuel oil

hp horsepower

ICCT International Council on Clean Transportation

IFO intermediate fuel oil

IMO International Maritime Organization

kg kilograms

kWh kilowatt-hours

LNG liquefied natural gas

LPG liquefied propane gas

LSFO low sulfur fuel oil

m

3

cubic meters

MARPOL International Convention for the Prevention of Pollution from Ships

MCR maximum continuous rating

MDE marine diesel engine

MDO marine diesel oil

MEPC Marine Environment Protection Committee

MGO marine gas oil

MSAR SFO Multiphase Superfine Atomized Residue Synthetic Fuel Oil

MT million metric tons (million tonnes)

Mtpa million tons per annum

MWh Megawatt-hours

NEMS National Energy Modeling System

nm nautical miles

NOx oxides of nitrogen
vi

NO2 nitrogen dioxide

NPDES National Pollutant Discharge Elimination System

NPV net present value

ODS ozone depleting substances

OGV ocean going vessel

O&M operating and maintenance

PAH polycyclic aromatic hydrocarbons

RFO residual fuel oil

R&D research and development

rpm revolutions per minute

SCR Selective catalytic reduction

SOx oxides of sulfur

SO2 sulfur dioxide

SO3 sulfur trioxide

SSD slow speed diesel

TDM Transportation Demand Module

TEU twenty-foot equivalent unit

U.S. United States

VLCC very large crude carrier

VSR vessel speed reduction
vii

Executive Summary

The National Energy Modeling System (NEMS) is the primary analysis tool for projections of 

domestic energy markets by the United States (U.S.) Energy Information Administration (EIA). 

The NEMS model can be used to understand the impacts that current energy and environmental 

issues and policies may have on energy markets. This particular study focuses on how a 

treaty/policy issue might affect the waterborne freight component of the Freight Transportation 

Submodule within the Transportation Demand Module (TDM) of NEMS.

The International Convention for the Prevention of Pollution from Ships (MARPOL) is the main 

international convention covering prevention of pollution of the marine environment by ships.

Committees of the International Maritime Organization (IMO) meet periodically to consider and 

adopt revisions to the various annexes of MARPOL and related treaties. Annex VI (Prevention 

of Air Pollution from Ships) entered into force on May 19, 2005. Annex VI sets limits on sulfur 

oxides (SOx) and oxides of nitrogen (NOx) emissions from ship exhausts and prohibits deliberate 

emissions of ozone depleting substances (ODS).

Annex VI also designated emission control areas (ECAs), which set more stringent standards for 

SOx, NOx, and particulate matter emissions. The IMO has designated waters along the U.S. and 

Canadian shorelines as the North American ECA for the emissions of NOx and SOx (enforceable 

from August 2012) and waters surrounding Puerto Rico and the U.S. Virgin Islands as the U.S.

Caribbean ECA for NOx and SOx (enforceable from 2014).1The ECAs ensure that foreign 

flagged vessels comply with IMO Tier III NOx limits while in U.S. waters. Tier III NOx limits 

will apply to all ships constructed on or after January 1, 2016, with engines over 130 kW that 

operate inside a NOx ECA area.

The North American ECAs generally extend 200 nautical miles (nm) from the U.S. and 

Canadian ports (50 nm for the U.S. Caribbean ECA), and their requirements went into effect on 

January 1, 2015. The new requirements mandate that existing ships either burn fuel containing a 

maximum of 0.1% sulfur or use scrubbers to remove the sulfur emissions. New ships will be 

built with engines and controls to handle alternative fuels and meet the ECA limits.

 

1 The North American ECA does not include the Pacific U.S. territories, smaller Hawaiian Islands, the Aleutian 

Islands and Western Alaska, and the U.S. and Canadian Arctic waters. The U.S. Caribbean ECA includes the waters 

adjacent to the Commonwealth of Puerto Rico and the U.S. Virgin Islands out to approximately fifty nautical miles 

from the coastline.
viii

This report begins with an assessment of the 2012 fuel usage of ocean going vessels within the 

ECAs based on data about 2012 port calls in the U.S. The nautical miles traveled that year are 

calculated for each U.S. Census Division, and the average dead weight tonnages are used to 

compute the number of ton-miles traveled in ECA Waters. The ship weights determine the likely 

engine sizes and design speeds. Because slow steaming practices indicate significant fuel 

savings, 2012 estimates were used to compute the transit times and fuel requirements. Auxiliary 

fuel consumption was based on estimates for both the transit time and time in ports. Figure ES- 1

shows the estimate for total fuel consumed within the ECAs in the U.S. Census Divisions based 

on the ocean-going vessel (OGV) type.2

Compliance options associated with travel in the ECAs for new vessels include using exhaust 

controls (e.g., scrubbers and selective catalytic reduction), changing fuels to marine gas oil 

(MGO) or liquefied natural gas (LNG), or installing engine-based controls (e.g., exhaust gas 

recirculation). Other technologies (e.g., biofuels and water injection) are also under development 

but have not yet reached wide-scale adoption.

 

2 Note that the total fuel consumed per voyage will be much greater. The ECA represents only 3.5 percent of the 

distance between Shanghai, China and Los Angeles and 5.9 percent of the distance between Rotterdam, NL and 

New York/New Jersey. Some general assumptions about speeds and times in port show that a voyage from Shanghai 

to Los Angeles would spend 12 to 15 percent of the time in an ECA, and a voyage from Rotterdam to New York 

would spend 36 to 41 percent of the time in ECAs.

Figure ES- 1. Total 2012 Fuel Consumed by OGVs within ECAs by U.S. Census Divisions 

Based on Vessel Type
ix

Ship efficiency improvements, shipping demand changes, and fuel price fluctuations will also 

drive future fuel consumption predictions within the North American and U.S. Caribbean ECAs. 

Using the 2012 estimates as a basis and the reference case for the Annual Energy Outlook 2014 

as growth projections, the fuel consumption was estimated for future years. A sample chart in 

Figure ES- shows that residual fuel oil consumption in the ECAs drops precipitously in 2015 

when the ECA provisions begin but rises again when scrubbers are installed on the new fleet of 

ships.3 Distillate fuel oil is used to cover the gap until emission controls and fuel switching

systems are installed aboard ships. Implementation of the recommendations in Section 5 (e.g., 

quantification of emission control installation rates for retrofits) might improve the estimates.

 

3

Figure ES-2 shows a large increase in distillate fuel oil for the coastal ECA activity. However, readers should 

understand that other vessels at U.S. ports already operate with distillate fuel oil blends (e.g., barges and tugs on 

inland waterways). According to U.S. Army Corps of Engineers statistics for 2013 

(http://www.navigationdatacenter.us/factcard/factcard14.pdf), U.S. coastal and inland waterborne activities were 

responsible for 240 and 252 billion ton-miles of transport, respectively, and inland vessels operate on distillate. 

Therefore, the substantial increase in distillate fuel oil shown in Figure ES-2 should not give readers the impression 

that a sudden demand for distillate fuels would be created in 2015. 

Figure ES- 2. Sample Projections of Fuel Consumed Within North American and 

U.S. Caribbean ECAs by NEMS Fuel Type
1

1 Introduction

The National Energy Modeling System (NEMS) is the primary analysis tool for projections of 

domestic energy markets by the U.S. Energy Information Administration (EIA). The NEMS 

model can be used to understand impacts that current energy and environmental issues and 

policies have on energy markets. This particular study focuses on how a treaty/policy issue might 

affect the waterborne freight component of the Freight Transportation Submodule within the 

Transportation Demand Module (TDM) of NEMS.

The International Convention for the Prevention of Pollution from Ships (MARPOL) is the main 

international convention covering prevention of pollution of the marine environment by ships.

Committees of the International Maritime Organization (IMO) meet periodically to consider and 

adopt revisions to the various annexes of MARPOL and related treaties. Annex VI (Prevention 

of Air Pollution from Ships) entered into force on May 19, 2005. Annex VI sets limits on sulfur 

oxides (SOx) and oxides of nitrogen (NOx) emissions from ship exhausts and prohibits deliberate 

emissions of ozone depleting substances (ODS).

Annex VI also designated emission control areas (ECAs) which set more stringent standards for 

SOx, NOx, and particulate matter emissions. The IMO has designated waters along the U.S. and 

Canadian shorelines as the North American ECA for the emissions of NOx and SOx (enforceable 

from August 2012) and waters surrounding Puerto Rico and the U.S. Virgin Islands as the U.S.

Caribbean ECA for NOx and SOx (enforceable from 2014). The ECAs ensure that foreign 

flagged vessels comply with IMO Tier III NOx limits while in US waters. Tier III NOx limits will 

apply to all ships constructed on or after January 1, 2016, with engines over 130 kW that operate 

inside a NOx ECA area.

The North American ECAs generally extend 200 nautical miles (nm) from the U.S. and 

Canadian ports (50 nm for the U.S. Caribbean ECA), and their requirements went into effect on

1 January 2015. The new requirements mandate that existing ships either burn fuel containing a 

maximum of 0.1% sulfur or to use scrubbers to remove the sulfur emissions. New ships will be 

built with engines and controls to handle alternative fuels and meet the ECA limits.

This report focuses on how the introduction of North American and U.S. Caribbean ECAs will 

affect fuel usage by ocean going vessels (OGVs). Because fuel usage from ships is not generally 

reported, Chapter 2 addresses the estimates to establish a 2012 baseline of fuel consumption (by 

billion British thermal units [Btus]) for ships traveling in each of the U.S. Census Divisions and 

Puerto Rico. Section 3 discusses MARPOL Annex VI and the associated U.S. Environmental 

Protection Agency (EPA) regulations associated with waterborne vessels, as well as discussion 

about compliance options. Section 4 focuses on how future projections can be made that account 

for ship efficiency improvements, shipping demand changes, and fuel price fluctuations. Section

5 gives recommendations for future model improvements as more data become available.
2

2 Baseline Current Estimates

The methodology used to calculate the baseline for energy consumption by ships calling on the 

U.S. ports that traveled through the North American and U.S. Caribbean ECAs is explained in 

this Section. Even though the ECAs were not in effect in 2012, the numbers, types and sizes of 

the vessels used in the baseline were based on the ships calling on the U.S. ports during the year 

2012. The most recent year for which these data are published by the U.S. Maritime 

Administration (MARAD) is 2012. These data are contained in the MARAD ‘2012 Total Vessel 

Calls - U.S. Ports, Terminals and Lightering Areas Report.’ Based on these data, the typical 

engine size and design speed of each ship type can be determined. Studies conducted by the IMO 

and collaborated by other sources have established fuel consumption rates based on engine 

output and have also documented the average speed (as a percentage of ship design speeds) that 

was used by each type and size ship during 2012.

The ship types in the MARAD report are: 

 Tanker (both petroleum and chemical tankers), 

 Container (container carriers and refrigerated container carriers), 

 Gas (liquefied natural gas [LNG], liquefied petroleum gas [LPG] and LNG/LPG 

carriers), 

 Dry Bulk (bulk vessels, bulk container ships, cement carriers, ore carriers, and wood-chip 

carriers), 

 Roll-On/Roll-Off (roll-on/roll-off vessels, roll-on/roll-off container ships, and vehicle 

carriers), and 

 General Cargo (general cargo carriers, partial container ships, refrigerated ships, barge 

carriers, and livestock carriers). 

Through the use of U.S. Army Corps of Engineer’s Waterborne Commerce of the United States, 

Calendar Year 2012, Part 5– National Summaries and MARAD’s Vessel Calls Snapshot-2011

(Revised: November 2013), the number of Tanker and Dry Bulk ships transporting energy 

products and the number of Gas ships transporting Liquid Natural Gas (LNG) were determined. 

The 2012 fuel consumption baseline yields fuel consumption by Census Divisions and ship types 

(Figure 2-1).4

This section discusses the calculations and assumptions used in developing the energy 

consumption baselines, considerations of issues that can induce error into the final calculations, 

and recommendations for refining the model over time.

The baseline current estimates are not envisioned to be calculated directly within NEMS 

modules, so this Section does not directly refer to programming variables and matrices. 

However, there may be a need to update the baseline with new information as the protocols are 

implemented. Therefore, Appendix A shares how matrix-based variables might be related to 

computation of these baseline estimates.

 

4 The MARAD report showed no vessels with DWT over 10,000 tons calling on seaports in the Midwest (IL, IN, 

MI, OH, and WI), West North Central (IA, KS, MN, MO, NE, ND, and SD), or Mountain (AZ, CO, ID, MT, NV, 

NM, UT, and WY) Census Divisions, so the tables and figures in this chapter do not include these Census Divisions.
3

2.1 Grouping the Ships

The average dead weight tonnage (dwt) of each vessel type making port calls to deepwater ports 

in the U.S. was derived from data in the U.S. Maritime Administration (MARAD) 2012 Total 

Vessel Calls - U.S. Ports, Terminals and Lightering Areas Report – for vessels over 10,000 dwt.

5

The MARAD data provides the total number of port calls and total dwt (listed under capacity) 

for each ship type by port. For example, Table 2-1 lists the ports in the Pacific Census Division 

and tanker ship calls. Figure 2-2 provides the results of the calculations of this process that were 

repeated for each Census Division and type of ship. 

Table 2-1. Estimating Average DWT of Tanker Ships Operating in the Pacific Census 

Division

Port State

ECA distance

(nautical miles/call)

Tankers

Calls Capacity

Anacortes WA 586 - - 

Anchorage AK 764 9 476,000

Cherry Point Refinery WA 616 248 26,138,862

Columbia River OR 572 104 4,403,989

Coos Bay OR 400 - -

Drift River Terminal AK 400 7 324,358

Dutch Harbor AK 400 11 490,752

El Segundo Offshore Oil 

Terminal

CA 400 304 30,487,664

Everett WA 624 - -

Ferndale WA 610 80 10,846,865

Grays Harbor WA 400 1 27,000

 

5 U.S. Department of Transportation Maritime Administration. 2012 Total Vessel Calls - U.S. Ports, Terminals and 

Lightering Areas Report. Last accessed from 

http://www.marad.dot.gov/library_landing_page/data_and_statistics/Data_and_Statistics.htm on January 22, 2015.

Figure 2-1. Total Fuel Consumed in 2012 by Ship Type in Census Divisions That Have 

Seaports
4

Port State

ECA distance

(nautical miles/call)

Tankers

Calls Capacity

Hilo HI 400 - -

Honolulu HI 400 118 10,612,636

Kahului HI 400 - -

Kalaeloa (Barbers Point) HI 400 120 12,487,384

Kenai AK 616 6 277,416

Kodiak AK 400 - -

Long Beach CA 400 965 102,829,099

Los Angeles CA 400 222 11,280,721

Manchester WA 648 21 1,219,033

March Point WA 618 276 25,738,712

Nikiski AK 616 76 3,918,520

Olympia WA 732 - -

Point Wells WA 618 13 606,295

Port Angeles WA 512 271 31,707,930

Port Hueneme CA 400 14 653,866

Red Dog Mine AK 400 2 128,159

San Diego CA 100 3 98,285

San Francisco Bay Area CA 400 1,601 110,513,536

Seattle WA 640 27 1,137,244

Tacoma WA 680 37 4,376,035

Valdez AK 400 260 33,378,365

TOTAL 4,796 424,158,726

AVERAGE DWT PER CALL 88,440

Considerations in the calculations:

1. The classification of 10,000 dwt (and above) will essentially capture all international and 

coastal ship commerce and nearly all barge operations to Puerto Rico, Hawaii, and 

Alaska from the continental United States.

2. The size of an LNG ship normally is stated as the ship’s obtainable volumetric capacity 

of liquid natural gas in cubic meters (m3). Multiplying the dwt by a factor between 1.8 

and 2.1 (depending on the ship size and tank configuration) will provide a rough 

approximation of the volumetric LNG capacity in m3of the LNG ship. 

3. Waterborne commerce on the inland rivers is generally excluded from these data reports, 

but the following deep water ports on rivers are included in this analysis:

a. Albany, New York located on Hudson River

b. Philadelphia, Pennsylvania located on Delaware River

c. Baton Rouge, Louisiana located on Mississippi River

d. Portland, Oregon located on the Columbia River
5

4. The waterborne commerce on the inland rivers (other than the deep water ports listed) 

generally operates outside the ECA.

5. Tug (tow) boats involved in barge operations to/from Puerto Rico, Hawaii, and Alaska 

from continental United States are not captured in these data. However, those barges are 

generally over 10,000 dwt and therefore the shipments are captured in the data. 

Generally barges designed for ocean service are at least 330 feet in length and at least

10,000 dwt. 

6. Vessels operating on the Great Lakes are not operating in the designated North American 

ECA and are not included in these data.

7. Cruise ships, fishing vessels, offshore supply boats, and harbor tug boats are not 

considered in the model because they are not generally involved in the commerce of 

coastal or international transport of goods within the scope of this project.

8. The four lightering areas off the coasts of California, Louisiana, and Texas were not 

included in this study because the tanker vessels traveling from the lightering areas to the 

ports are already counted in the port data.

2.2 Determining Engine Size and Design Speed of Each Ship Grouping

The speed at which a ship will be operated is contingent on many factors, including the type of 

service (e.g., container, tanker or other) the ship will operate, customer expectations, daily 

operating/bunker costs, and economic climate. “Fuel consumption for a ship can be 

approximated by a cubic function of the ship’s speed.”6 Generally tanker and dry bulk ships 

operate at slower speeds than container ships. Roll-on/Roll-off, gas, and general cargo ships 

 

6

‘Ship Speed Optimisation with Time-Varying Draft Restrictions’, by Elena Kelareva, Philip Kilby, Sylvie 

Thiébaux, http://www.nicta.com.au/pub?doc=6886

Figure 2-2. Average DWT of Each Vessel Type by Census Division
6

operate at speeds faster than tankers and slower than container ships. General guidelines 

matching vessel types to engine output by dwt are published by MAN Diesel & Turbo7and other 

major engine manufacturers. In addition, detailed analyses have been published by Gdynia 

Maritime University8and others.

The size of the engine required for each ship profile (Table 2-2) and their design speeds (Table 

2-3) used in the model were derived from data published by Gdynia Maritime University and 

MAN Diesel & Turbo. The design speed is a trend based on assumptions by the industry of the 

maximum sustained speed that ships of a certain size and vessel type should be capable of 

operating at under normal economic and physical conditions. During normal economic 

conditions (those upon which the trends were developed), ships were expected to operate at or 

near their design speeds.

9 However, the considerations below discuss the common practice of 

slow steaming.

Table 2-2. Ship Engine Output (kW) for Each Ship Profile

Census Division Tankers Containers

Gas 

(LPG/LNG)

Roll-On/

Roll-Off Bulk

General 

Cargo

New England 9,400 42,000 8,000 10,000 8,400 12,000

Middle Atlantic 10,500 37,600 8,000 12,000 8,700 8,000

South Atlantic 8,500 33,600 12,000 10,000 10,000 10,000

East South Central 10,800 21,700 8,000 10,000 9,700 14,000

West South Central 9,400 30,100 8,000 10,000 9,000 10,000

Pacific 12,500 41,500 8,000 10,000 8,900 14,000

Puerto Rico 9,400 14,000 8,000 8,000 7,200 7,000

Table 2-3. Ship Design Speed (Knots) for Each Ship Profile

Census Division Tankers Containers

Gas 

(LPG/LNG)

Roll-On/

Roll-Off Bulk

General 

Cargo

New England 15.0 24.7 17.5 18.0 14.5 18.0

Middle Atlantic 15.0 24.2 15.0 18.0 14.5 18.0

South Atlantic 15.0 23.8 17.0 18.0 14.5 18.0

East South Central 15.0 22.0 15.0 18.0 14.5 18.0

West South Central 15.0 23.0 15.0 18.0 14.5 18.0

Pacific 15.0 24.6 15.0 18.0 14.5 18.0

Puerto Rico 15.0 20.0 15.0 18.0 14.5 18.0

 

7

Propulsion Trends’ in LNG Carriers, container, bulk Two-stroke Engines series published by MAN Diesel & 

Turbo, Teglholmsgade 41, 2450 Copenhagen SV, Denmark; info-cph@mandieselturbo.com; 

www.mandieselturbo.com

8

‘Analysis of Trends In Energy Demand For Main Propulsion, Electric Power And Auxiliary Boilers Capacity Of 

General Cargo And Container Ships,’ Zygmunt Górski, Mariusz Giernalczyk, Gdynia Maritime University 83 

Morska Street, 81-225 Gdynia, Poland, e-mail: magier@am.gdynia.pl, zyga@am.gdynia.pl

9 Collected data indicates that ships have not been operating near design speeds for the last six years.
7

Considerations in the calculations and variations from design speeds:

1. Minor changes in ship speed can impact ship engine output requirements significantly.

2. The optimal load range of the two-stroke engine lies between 70 and 85 percent of its 

design load.

10

 Engine loads below 60 percent are generally considered to be slow 

steaming.

11 The IMO reported that the average ratio of operating speed to design speed 

was 0.85 in 2007 and 0.75 in 2012.

12 This ratio (expressed as a percentage) for each 

vessel type in 2012 is provided in Table 2-4.

3. Table 2-5 provides the percentage of engine output/load that each vessel type was 

operating at during 2012. 

Table 2-4. Slow Speed Steaming Reduction in Ship Speed by Vessel Type (Percentage of 

Design Speed)

Census Division Tankers Containers

Gas 

(LPG/LNG)

Roll-On/

Roll-Off Bulk

General 

Cargo

New England 80% 68% 68% 73% 82% 82%

Middle Atlantic 81% 68% 73% 73% 82% 82%

South Atlantic 80% 68% 68% 73% 83% 82%

East South Central 81% 70% 70% 73% 83% 82%

West South Central 80% 68% 70% 73% 82% 82%

Pacific 78% 68% 70% 73% 82% 82%

Puerto Rico 80% 73% 70% 73% 82% 82%

 

10 Slow steaming – a viable long-term option?; Andreas Wiesmann; Wärtsilä Technical Journal; February 2010. 

www.wartsila.com

11 There is some variation in the definitions used to define slow steaming. Some definitions link slow steaming to 

speeds below a certain nautical miles per hour (knots) while others link it to a percentage of engine output/load. 

Engine load is used in the calculations in this model. 

12 International Maritime Organization, Marine Environment Protection Committee. Reduction of GHG Emissions 

from Ships: Third IMO GHG Study 2014 – Final Report. 67th session Agenda item 6, MEPC 67/INF.3, July 25, 

2014.

Reducing the nominal ship speed from 27 to 22 knots (-19%) will reduce the engine power to 42% of its nominal 

output. This results in an hourly main engine fuel oil savings of approximately 58%.

A further reduction down to 18 knots could save 75% of the fuel. The reduced speed however results in a longer 

voyage time; therefore the fuel savings per roundtrip (for example AsiaEurope-Asia) are reduced by 45% at 22 

knots, or 59% at 18 knots. These are calculated values, and the actual values depend also on a number of 

external factors, such as the loaded cargo, vessel trim, weather conditions, and so on.”1

An example of the results of slow speed steaming provided by Wärtsilä
8

Table 2-5. Slow Speed Steaming Reduction in Ship Power Output by Vessel Type 

(Percentage of Design Power)

Census Division Tankers Containers

Gas 

(LPG/LNG)

Roll-On/

Roll-Off Bulk

General 

Cargo

New England 55% 36% 36% 45% 58% 59%

Middle Atlantic 57% 36% 45% 45% 58% 59%

South Atlantic 55% 36% 36% 45% 60% 59%

East South Central 57% 39% 39% 45% 60% 59%

West South Central 55% 36% 39% 45% 58% 59%

Pacific 51% 36% 39% 45% 58% 59%

Puerto Rico 55% 45% 39% 45% 58% 59%

4. A rule of thumb calculation indicates that a 10 percent decrease in speed will result in a 

19 percent reduction in engine power (on a tonne-mile basis).13 The rule of thumb is valid 

for most engine loads that exceed 25 percent of the maximum continuous rating (MCR), 

so it should be appropriate in these calculations.

2.3 Calculating Fuel Oil Consumption 

Fuel oil consumption rates (Table 2-6) for ship main propulsion engines (commonly called the 

marine diesel engine [MDE]) were based on IMO data12 and assume:

1. MDEs are two-cycle engines that burn IFO (Figure 2-3),

2. MDEs are slow speed diesel (SSD) engines,

3. Ships have one engine with one propeller and are direct drive (no transmission), and

4. Engines were built after 2001.

Table 2-6. Fuel Oil Consumption Rates for Slow, Medium and High Speed Diesel Engines 

(kg/kWh)

12

Engine Age Slow speed diesel Medium speed diesel High speed diesel

Before 1983 0.205 0.215 0.225

1984-2000 0.185 0.195 0.205

After 2001 0.175 0.185 0.195

 

13 Faber, J., M. Freund, M. Kőpke, and D. Nelissen. Going Slow to Reduce Emissions: Can the current surplus of 

maritime transport capacity be turned into an opportunity to reduce GHG emissions?; January 2010; Seas At Risk, 

Copyright © 2010; The production of the report was supported by the Dutch Ministry for Environment, Spatial 

Planning and Housing (VROM) and the European Commission (DG Environment). Last accessed from 

http://www.seas-at-risk.org/1mages/GoingSlowToReduceEmissions_1.pdf on January 22, 2015.
9

To calculate fuel oil consumption (kg) for the MDEs, the slow steaming engine output (kW) was 

multiplied by 0.175 kg/kWh and the time operating in the ECA (hours). 

Considerations in the calculations:

1. The fuel oil consumption rates (0.175 kg/kWh) for the MDEs matched those in the IMO

studies, but the IMO reports a range of observed rates from 0.165 to 0.185 kg/kWh.

2. The heating values of ship bunker fuels are not set by standards and vary by supplier. The 

heating value is generally agreed upon in the purchase agreement between the buyer and 

seller, so the kilogram basis is only a placeholder for a later conversion on a Btu basis.

3. Ships used to transport LNG generally are equipped with one of three engine 

configurations options. The older ships use forced natural gas boil-off from the cargo 

tanks in steam boilers to produce steam for steam turbines. Although the conventional 

steam propulsion system has a low efficiency of about 28% compared to the 

approximately 50% for a conventional slow speed diesel engine, this option had the 

advantage of simplicity (no additional fuel tanks, or equipment to convert a SSD to run 

on LNG). As the selling price of natural gas began to rise, some ships were built to utilize 

the naturally occurring boil-off gas in a dual fuel (heavy fuel and compressed natural gas) 

diesel engine for main propulsion. In some of the largest LNG ships, an SSD engine for 

ordinary heavy fuel oil was used for main propulsion. Because few LNG port calls 

occurred in 2012, the difficulty of determining the engine option being used in each port 

call, and the acknowledgement that the introduced error would be insignificant in the 

national and Census Division totals, the increased fuel consumption required for forced 

gas boil-off/boilers/steam turbine propulsion was not calculated. 

2.3.1 Time ship will be operating in the ECA

The computed hours of operation in the ECA are found by multiplying the number of port calls 

by the distance traveled and vessel travel speed. The U.S. Caribbean ECA waters extend 50 

nautical miles (nm) from the shoreline, so the ECA distance traveled to the four Puerto Rican 

ports was assumed to be 100 nm (50 nm reaching and 50 nm leaving the port). The North 

Figure 2-3. Most Common Ship Bunker Fuels
10

American ECA waters generally extend 200 nm from the shoreline, so the traveled distance is 

assumed to be 400 nm for other ports.14

The vessel travel speeds are computed by multiplying the design speeds (Table 2-3) by the slow 

steaming reductions (Table 2-4). Figure 2-4 shows the travel times for the fleets by vessel type 

for each Census Division. The largest bar (time for tanker calls in the West South Central Census 

Division) in Figure 2-4 is much larger than other bars because 20 percent of the nation’s 2012 

port calls were by tankers to Texas and Louisiana ports.

Considerations in the calculations:

1. The following ports can be accessed by avoiding part of the ECA (Appendix B):

Port Reason ECA is Abridged Total Effective ECA

San Diego, CA Proximity to Mexican waters (Figure B-1) 10 nm

Brownsville, TX Proximity to Mexican waters (Figure B-1) 7 nm

Miami, FL Proximity to Bahamian waters (Figure B-2) 25 nm

Port Everglades, FL Proximity to Bahamian waters (Figure B-2) 25 nm

Palm Beach, FL Proximity to Bahamian waters (Figure B-2) 25 nm

2. Some ports have longer effective ECAs as a result of their placements significantly 

inland of the shore baseline. Waterways that link the oceans to these deepwater ports 

would be considered to be U.S. navigable waters.15 The EPA regulations used to 

implement the ECA requirements also apply to U.S.-flagged vessels wherever located 

and to foreign-flagged vessels operating in the U.S. navigable waters or the U.S.

Exclusive Economic Zone (EEZ). These situations occurred in the following regions: 

Cook Inlet in Alaska, Puget Sound in Washington, Columbia River in Oregon, 

 

14 Several exceptions with different travel distances are discussed in the Considerations section.

15 This is not an exclusive definition of navigable waters; there are many other waterways that are also considered to 

be navigable waters.

Figure 2-4. Time (in Thousands of Hours) Each Vessel Type Operated in the ECA 

Waters in 2012
11

Mississippi River in Louisiana, Chesapeake Bay in Maryland, Delaware River for 

Delaware and Pennsylvania, and the Hudson River in New York. 

3. Some ships that call on more than one U.S. port may opt to transit from one port to 

another without leaving the ECA. This might introduce error into the model, but the 

introduced errors are expected to be mostly insignificant because:

a. Most major port areas in the U.S. are spaced apart by more than 200 nm, so travel 

outside the ECA would often be economical.

b. Using a ship to move goods short distances is generally not cost effective due to 

added port fees and terminal fees. Transport of cargo across short distances is 

usually conducted by truck, rail, or pipelines.

4. Ships may choose to operate at speeds slower than their slow steaming speed for many 

reasons, including: regulatory speed limits, ship traffic, weather/sea conditions, 

navigational requirements, or to take on a tugboat assist. Such ship speed reductions 

would inflate estimated consumption totals but only near the ports.

2.3.2 Power consumption in propelling the ships through the ECA

Table 2-7 estimates the energy in GWh used to propel ships through the ECA and was calculated 

by multiplying the total time (by vessel type) that the ships operated in the ECA by the engine 

slow steaming output for each vessel type.

Table 2-7. Power Spent for Propulsion Through the ECA (GWh)

Census Division Tankers Containers

Gas 

(LPG/LNG)

Roll-On/

Roll-Off Bulk

General 

Cargo

New England 110 56 4.1 21 33 7.7

Middle Atlantic 420 850 6.0 110 70 100

South Atlantic 260 2,400 17 460 470 170

East South Central 120 97 3.7 11 100 41

West South Central 2,300 480 62 61 770 220

Pacific 1,200 2,600 6.2 287 750 140

Puerto Rico 13 21 0.6 5.4 2.1 3.7

Nationwide 4,400 6,500 99 950 2,200 680

2.3.3 Auxiliary power consumption

In addition to fuel consumed by the MDE, ships are generally operating auxiliary power units 

that provide ship electricity, running water, and warm the IFO so that it burns efficiently. In this 

model the auxiliary power required was assumed to be equal to 5 percent of the MDE design 

output.16 Auxiliary power systems operate when the MDEs are operating and while ships are in 

port or at anchor. This model initially assumed that the ship would be in port and/or at anchor for 

 

16 Same assumption used in footnote 12. The 5 percent assumption is also supported by Table 1 of the California 

regulation calling for airborne toxic control measures from ocean-going vessels; the default auxiliary power 

requirements listed in that table (4000-4999 TEUs) closely match 5 percent of the propulsion engine estimates for 

average vessels in New England, Middle Atlantic, and Pacific Census Divisions (representing more than half of the 

2012 container vessel capacity). 
12

72 hours (3 days) for each port call, but Appendix D describes how the estimates were refined 

based on available data indicating that port times are mandated to be short:

 1.8 days for container ships

 1.5 days for tanker vessels

 2.6 days for general cargo vessels

 0.88 days for roll-on/roll-off vessels

 1.5 days for gas vessels

 2.0 days for bulk vessels

The auxiliary power spent in an ECA was calculated by multiplying the hourly auxiliary power

times the sum of the number of transit hours in the ECA and the port time. 

Table 2-8 lists the auxiliary power estimates by Census Division for each vessel type. The large 

number of container ship port calls into Hampton Roads, Virginia and Savannah, Georgia yield 

the highest numbers for the South Atlantic Census Division.

Table 2-8. Auxiliary Power Spent in ECA and Port (GWh)

Census Division Tankers Containers

Gas 

(LPG/LNG)

Roll-On/

Roll-Off Bulk

General 

Cargo

New England 21 22 1.2 3.9 7.0 2.1

Middle Atlantic 71 320 1.1 20 13 23

South Atlantic 49 950 4.7 82 90 45

East South Central 22 33 0.9 2.1 21 11

West South Central 420 170 15 12 150 59

Pacific 220 920 1.4 51 140 34

Puerto Rico 6 17 0.4 1.2 1.2 3.2

Nationwide 820 2,400 25 170 420 180

Fuel consumption rates for auxiliary power are assumed to be 0.225 kg/kWh (based on Table 

2-9). This number is used to convert the power spent into fuel consumption.

Table 2-9. Fuel Oil Consumption Rates (grams/kWh) for Auxiliary Power12

Engine Type RFO MDO/MGO

Gas turbine 305 300

Steam boiler 305 300

Auxiliary engine 225 225

Considerations for calculations:

1. Auxiliary power fuel consumption remains less documented than consumption rates by 

the MDE. While this study and the IMO are basing the size of the auxiliary power units 

as 5 percent of the MDE size, some reports have indicated auxiliary power may be up to 

10 percent or higher of the size of the MDE. Auxiliary power warms the IFO prior to 

injection into an engine and provides the ships with electricity, hot water, and heat. 
13

Container ships and ships with large refrigeration systems will consume more electricity 

than comparably sized dry bulk and tank ships. 

2. Auxiliary power fuel consumption will exceed 5 percent of the total fuel consumption of 

the 2012 baseline totals because: 

a. MDEs are operated below design loads; 

b. Auxiliary power has a higher fuel consumption rate per kW than the MDE; and

c. Auxiliary power continues operation while the ship is in port or at anchor. 

3. Ships with waste heat capture units may greatly reduce the amount of fuel consumed by 

auxiliary power. Future IMO studies will probably study auxiliary power in more detail,

and these baseline estimates should be revised if the IMO changes its estimates for 

auxiliary power.

2.3.4 Fuel consumed in 2012

The 2012 fuel consumption numbers for transiting the ECA were calculated by multiplying the 

spent power for propulsion (GWh) by the fuel consumption rate of 0.175 kg/kWh and the 

conversion of 42,195 Btu/kg (based on the NEMS heating value for residual oil17). The 2012 

fuel consumption numbers for auxiliary engines are calculated in a similar manner using a fuel 

consumption rate of 0.225 kg/kWh. Both sets of data are presented in Figure 2-5.

To obtain the total fuel oil consumption used in each of the Census Divisions by vessel type, the 

fuel consumption values used for transiting the ECA were added to those used for auxiliary 

power. Table 2-10 displays the combined totals by Census Divisions, nationally, and by vessel 

type.

Table 2-10. Total Fuel Consumed in 2012 for Transit and Auxiliary Power (Billion Btus)

Census 

Division Tankers Containers

Gas 

(LPG/LNG)

Roll-On/ 

Roll-Off Bulk

General 

Cargo Total

New England 1,000 620 41 190 310 77 2,300

Middle 

Atlantic 3,800 9,300 55 980 640 980 16,000

South Atlantic 2,400 26,000 170 4,200 4,400 1,700 39,000

East South 

Central 1,100 1,000 36 100 940 410 3,600

West South 

Central 21,000 5,100 610 560 7,200 2,200 37,000

Pacific 11,000 28,000 60 2,600 6,800 1,300 49,000

Puerto Rico 150 320 8 60 27 57 630

Nationwide 40,000 71,000 980 8,700 20,000 6,700 150,000

 

17 Energy Information Administration. “Conversion Tables” from Annual Energy Outlook 2014. Last accessed from 

http://www.eia.gov/oiaf/aeo/tablebrowser/#release=AEO2014&subject=0-AEO2014&table=20-

AEO2014®ion=0-0&cases=ref2014-d102413a on January 16, 2015. 
14

Figure 2-5. Fuel Consumption in ECA Waters in 2012
15

2.4 Distribution Between Energy and Non-Energy Products

The NEMS model tracks energy product demands, imports, and exports in modules related to 

specific fuels (e.g., Coal Market Module and Liquid Fuels Market Module). Therefore, future 

projections of energy product imports and exports may be aligned directly with annual demands 

within the appropriate NEMS modules. Therefore, this section discusses the allocation of the 

2012 numbers between energy and non-energy products. Tankers, gas, and bulk ships will be 

divided into vessel subtypes.

2.4.1 Determining percentage of tankers and dry bulk ships transporting energy 

products 

Tankers and dry bulk ships transport both energy and non-energy products. To determine the 

number of tankers and dry bulk ships that transported energy products in 2012, the U.S. Army 

Corps of Engineer (ACOE) Waterborne Commerce of the United States, Calendar Year 2012, 

Part 5– National Summaries18 was reviewed and the total tonnage of products that are generally19

transported on tanker and on dry bulk ships was compared to the total tonnage of energy

products transported (foreign inbound, foreign outbound, or in coastal trade) as freight. 

Table 2-11 lists the products and tons shipped and illustrates that 97 percent of the tankers and 

51 percent of the dry bulk ships involved with U.S. port calls were transporting energy products. 

The total port calls by tankers and dry bulk ships were multiplied by these percentages to allocate 

the energy consumption within the ECAs between energy and non-energy products.

Considerations in calculations:

1. The ACOE statistics list products transported by commodity code, but not by the type of 

ship being used to transport the commodity. Relatively small amounts of these 

commodities may be shipped in drums or packages on container, roll-on/roll-off, or 

general cargo vessels. Likewise, shipment of commodities not normally shipped on dry 

bulk ships may be loaded onto a dry bulk ship under certain conditions. Tankers 

generally are certificated to transport specific products and are less likely to be used for 

other commodities.

2. The list of products used in this section may be revised over time as the issue is studied 

further.

 

18 U.S. Army Corps of Engineers. Waterborne Commerce of the United States: Calendar Year 2012 Part 5—

National Summaries. Last accessed from http://www.navigationdatacenter.us/wcsc/pdf/wcusnatl12.pdf on January 

22, 2015.

19 Based on professional opinion.
16

Table 2-11. Percentage of Product Moved on Tank Ships That Are Energy Products (Top). 

Percentage of Product Moved on Dry Bulk Ships That Are Energy Products (Bottom).

Non-energy (thousand short tons) Energy (thousand short tons)

Product Import Export Coastal Import Export Coastal

Crude oil -- -- -- 361,000 80 34,700

Gasoil -- -- -- 39,200 27,700 40,500

Kerosene -- -- -- 924 479 177

Distillate -- -- -- 64,000 71,200 20,500

Residual -- -- -- 5,310 5,580 9,880

Naphtha 1,270 2,540 1,140 -- -- --

Benzene 1,950 178 99 -- -- --

Sulfuric acid 503 47 3 -- -- --

Alcohols 8,800 4,140 3,000 -- -- --

Subtotal 12,500 6,900 4,250 471,000 105,000 106,000

Total 23,700 682,000

Percentage 3% 97%

Non-energy (thousand short tons) Energy (thousand short tons)

Product Import Export Coastal Import Export Coastal

Petroleum coke -- -- -- 2,530 36,200 751

Coal -- -- -- 9,210 120,000 4,510

Wood chips 2 1,480 259 -- -- --

Gypsum 3,580 66 232 -- -- --

Sand/gravel 8,140 689 2,960 -- -- --

Iron ore 7,530 9,870 -- -- -- --

Copper ore 14 546 4 -- -- --

Aluminum ore 16,400 1,760 406 -- -- --

Magnesium ore 479 4 -- -- -- --

Other ore 945 344 -- -- -- --

Grains 2,610 58,200 -- -- -- --

Oil seed 588 52,200 -- -- -- --

Subtotal 40,300 125,000 3,863 11,700 156,000 5,260

Total 169,000 173,000

Percentage 49% 51%

2.4.2 Determining number of gas carriers (ships) that are transporting LNG and LPG

LNG terminals are located in each of the Census Divisions except the Middle Atlantic (New 

York, New Jersey, and Pennsylvania). The ACOE statistics assign the same commodity code 

(2640) to LNG and LPG and the 2012 Total Vessel Calls Report does not separate LNG and 
17

LPG. However, a periodic report20 does provide annual totals for gas carriers (LNG and LPG) 

and breaks out LNG carriers for the years from 2006 to 2011. The total port calls for gas carriers 

were subtracted from this total and the average number of ‘total gas carrier’ port calls was 

computed and compared to the LNG carrier port calls. During this period it appears that LNG 

carriers accounted for 26 percent of the ‘total gas carrier’ port calls outside of the Middle 

Atlantic District (Table 2-12).

Table 2-12. LNG Carriers as a Percentage of Total Gas Carriers

Year Total Gas Carriers LNG Carriers

Percentage of 

LNG Vessels

2006 875 213

26±4%

2007 804 202

2008 703 171

2009 640 201

2010 670 202

2011 779 157

Average 745 191

In 2012 there were 747 total gas carrier port calls outside of the Middle Atlantic District and this 

equates to an estimated 194 LNG carrier port calls nationally. The total fuel consumption for gas 

ships in each Census Division (except the Middle Atlantic) were multiplied by 26 percent to 

allocate fuel consumption for LNG shipments, and the remainders were allocated to LPG 

shipments.

Considerations:

1. LNG ships tend to be larger than LPG ships, but this should not impact overall model 

projections. Gas ships are only responsible for less than 1 percent of the total fuel 

consumed in Table 2-10.

2. The computed percentage of LNG carriers as part of the larger total gas carrier numbers 

may be subject to rapid change due to fluctuations in both oil and natural gas pricing.

Table 2-13 shows the calculated 2012 fuel consumption numbers by vessel type and subtype (for 

tankers, gas ships, and bulk ships) among the Census Divisions. Nationally container ships 

represented almost half of the fuel consumed.

 

20 Vessel Calls Snapshot, 2011, Released: March 2013, Revised: November 2013, Office of Policy and Plans, 

Maritime Administration, U.S. Department of Transportation, www.marad.dot.gov/data_statistics.
18

Table 2-13. Total Fuel Consumed (Billion Btu) in 2012 by Vessel Type and Subtype (by 

Product Type)

Census 

Division

Energy 

Tankers

Nonenergy 

Tankers Containers

Gas 

(LNG)

Gas 

(LPG)

Roll-On/

Roll-Off

Bulk -

Energy

Bulk -

NonenergyGeneral 

Cargo Total

New England 1,000 31 620 11 30 190 160 150 77 2,300

Middle 

Atlantic

3,700 110 9,300 - 55 980 330 310 980 16,000

South Atlantic 2,300 72 26,000 43 120 4,200 2,200 2,100 1,700 39,000

East South 

Central

1,000 32 1,000 9 27 100 480 460 410 3,600

West South 

Central

20,000 630 5,100 160 450 560 3,700 3,500 2,200 37,000

Pacific 10,000 320 28,000 15 44 2,600 3,500 3,300 1,300 49,000

Puerto Rico 150 5 320 2 6 60 14 13 57 630

Nationwide 39,000 1,200 71,000 240 740 8,700 10,000 10,000 6,700 150,000

Fraction 26% 0.8% 48% 0.2% 0.5% 6% 7% 7% 5% --
19

3 Compliance Strategies

Marine vessels are significant sources of air pollutant and greenhouse gas (GHG) emissions. The

regulations governing vessel emissions in the North American and U.S. Caribbean ECAs will 

alter the ship fuels consumed in the future as well as alter the control devices operating on board 

the ships. This section details some of the provisions within the regulatory framework and also 

presents the most likely compliance strategies.

3.1 Regulatory Framework

This section describes both the U.S. EPA regulations and the IMO protocols.

3.1.1 U.S. EPA regulations

The U.S. emissions from compression-ignition MDEs have been regulated through a number of 

U.S. EPA regulations, the first of which was issued in 1999. Marine engine regulations overlap 

those for mobile, land-based non-road engines, but marine engines have no emission control 

requirements for particulate matter (smoke). 

Marine engines are divided into three categories in EPA regulations based on their displacement 

per cylinder, as shown in Table 3-1. Category 1 and Category 2 marine diesel engines typically 

range in size from about 500 to 8,000 kW (700 to 11,000 hp). Categories 1 and 2 (C1 and C2) 

are further divided into subcategories, depending on displacement and net power output. These 

engines are used to provide propulsion power on many kinds of vessels including tugboats, 

pushboats, supply vessels, fishing vessels, and other commercial vessels in and around ports. 

They are also used as stand-alone generators for auxiliary electrical power for many vessel types. 

Category 3 (C3) MDEs are very large and used for propulsion power on OGVs such as container 

ships, oil tankers, bulk carriers, and cruise ships. Category 3 engines typically range in size from 

2,500 to 70,000 kW (3,000 to 100,000 hp). 

Table 3-1. Marine Engine Categories

Category

Displacement per Cylinder (D)

Engine Technology Basis

Tier 1-2 

Emission Standards

Tier 3-4 

Emission 

Standards

1 D < 5 dm3and 

power ≥ 37 kW 

D < 7 dm3Land-based non-road diesel engines

2 5 dm3≤ D < 30 dm37 dm3≤ D < 30 dm3Locomotive engines

3 D ≥ 30 dm3 Unique marine engine design

The 1999 Marine Engine Rule adopted Tier 2 standards for C1 and C2 engines that are based on 

the standard for land-based non-road engines. At that time the largest C3 engines were expected

to comply with IMO’s MARPOL Annex VI Tier I standards set in 1997 but were not required to 

meet standards by the rule. In 2003, EPA introduced the C3 Engine Rule “Control of Emissions 

From New Marine Compression-Ignition Engines at or Above 30 Liters Per Cylinder” [40 CFR 

Part 9 and 94][68 FR 9745-9789, 28 Feb 2003]. The rule established Tier 1 emission standards 

for marine engines that were virtually equivalent to the IMO MARPOL Annex VI limits. 
20

In 2008 EPA finalized a three-part program that further reduced emissions from MDEs with percylinder displacements below 30 liters. This rule addressed marine propulsion engines used on 

vessels from recreational and small fishing boats to towboats, tugboats and Great Lake 

freighters, and marine auxiliary engines ranging from small generator sets to large generator sets 

on OGVs. The rule included the first-ever national emission standards for existing commercial 

MDEs, applying to engines larger than 600 kW when they are remanufactured. The rule also set 

Tier 3 emissions standards for newly built engines that were phased in beginning in 2009. 

Finally, the rule established Tier 4 standards for newly built commercial marine diesel engines 

above 600 kW, phasing in beginning in 2014. The Tier 4 emission standards were modeled after 

the 2007/2010 highway engine program and the Tier 4 non-road rule, with an emphasis on the 

use of exhaust control technology. 

To enable catalytic aftertreatment methods, EPA established a sulfur cap in marine fuels (as part 

of the non-road Tier 4 rule). The sulfur limit of 500 ppm became effective in June 2007, and the 

sulfur limit of 15 ppm replaced that in June 2012 (these sulfur limits are not applicable to 

residual fuels).

EPA’s 2009 Category 3 Engine Rule (published April 30, 2010) revised the standards that apply 

to C3 engines installed on U.S. vessels and to marine diesel fuels produced and distributed in the 

U.S. The rule added two new tiers of engine standards for C3 engines: Tier 2 standards that were 

enforceable in 2011 and Tier 3 standards that begin in 2016. Under this regulation, both U.S.-

flagged and foreign-flagged ships which are subject to the engine and fuel standards of 

MARPOL Annex VI (shown in Table 3-2) must comply with the applicable Annex VI engine 

and fuel sulfur limits provisions when they enter U.S. ports or operate in most internal U.S.

waters, including the Great Lakes. 

Table 3-2. MARPOL Annex VI NOx Emission Standards

Tier Effective Date

NOx Emission Limit (g/kWh)

RPM 

(n < 130)

RPM 

(130 ≤ n < 2000)

RPM 

(n ≥ 2000)

I 2004 17.0 45· n-0.2 9.8

II 2011 14.4 44· n-0.23 7.7

III 2016 * 3.4 9· n-0.2 1.96

* In NOx ECAs only (Tier II standards apply outside of ECAs).

The 2009 Category 3 Engine rule also revised EPA’s diesel fuel program to allow for the 

production and sale of diesel fuel with up to 1,000 ppm sulfur for use in C3 marine vessels, 

phasing in by 2015. Vessels were allowed to use other methods to achieve SOx emissions

reductions equivalent to those obtained by using the lower 1,000 ppm sulfur fuel. In the final 

action, EPA provided an exclusion of the application of the ECA-level fuel sulfur standards in 

MARPOL Annex VI to existing steamships operating on the Great Lakes and Saint Lawrence 

Seaway. An additional economic hardship relief provision was included in the regulation for 

vessels with diesel engines operating on the Great Lakes and Saint Lawrence Seaway. This 

option provides temporary relief from the 2015 ECA-level fuel sulfur standards upon 

demonstration that the burden of compliance costs would cause serious economic hardship.
21

In 2012, EPA revised the large marine engine regulation by adding a provision to provide an 

incentive to repower Great Lakes steamships with new, more efficient diesel engines. This 

consisted of an automatic, time-limited fuel waiver that allows the use of residual fuel in the 

replacement diesel engines that exceeds the global and ECA sulfur limits that otherwise apply to 

the fuel used in ships operating on the U.S. portions of the Great Lakes. This automatic Great 

Lakes steamship repower fuel waiver is valid through December 31, 2025. After that date, 

repowered steamships will be required to comply with the Great Lakes ECA fuel sulfur limits for 

diesel engines. This automatic fuel waiver is available only to steamships that operate 

exclusively on the Great Lakes, that were in service on October 30, 2009, and that are repowered 

with a Tier 2 or better diesel engine. 

3.1.2 IMO protocols

On the international front, the Marine Environment Protection Committee (MEPC) of the 

International Maritime Organization (IMO) is the United Nations agency concerned with the 

prevention of marine pollution from ships. The EPA participates on the U.S. delegation to the

IMO and submits position papers to the IMO’s MEPC suggesting measures to reduce air 

pollution and GHG emissions from ships. 

The International Convention for the Prevention of Pollution from Ships (MARPOL) is the main 

international convention covering pollution prevention of the marine environment by ships. The 

MARPOL Convention was adopted on November 2, 1973 at IMO. Committees of the IMO meet 

periodically to consider and adopt revisions to the various annexes of MARPOL and related 

treaties. Annex VI (Prevention of Air Pollution from Ships) entered into force on May 19, 2005. 

Annex VI sets limits on sulfur oxides (SOx) and oxides of nitrogen (NOx) emissions from ship 

exhausts and prohibits deliberate emissions of ozone depleting substances (ODS). 

The IMO emission standards are commonly referred to as Tiers I through III standards. The Tier 

I standards were defined in the 1997 version of Annex VI, while the Tier II/III standards were 

introduced by Annex VI amendments adopted in 2008. Annex VI applies retroactively to new 

engines greater than 130 kW installed on vessels constructed on or after January 1, 2000, or 

which undergo a major conversion after that date. In anticipation of the Annex VI ratification, 

most marine engine manufacturers had been building engines compliant with Tier I standards 

since 2000. Annex VI amendments were adopted in October 2008 and ratified by 53 countries 

(including the U.S.), representing 81.88 percent of the tonnage. The amendments became 

enforceable on 1 July 2010. They introduced:

 New fuel quality requirements beginning from July 2010,

 Tier II and Tier III NOx emission standards for new engines, and 

 Tier I NOx requirements for existing pre-2000 engines. 

Annex VI also designated ECAs, which set more stringent standards for SOx, NOx, and 

particulate matter emissions. The IMO has designated waters along the U.S. and Canadian 

shorelines as the North American ECA for the emissions of NOx and SOx (enforceable from 

August 2012) and waters surrounding Puerto Rico and the U.S. Virgin Islands as the U.S.

Caribbean ECA for NOx and SOx (enforceable from 2014). The ECAs ensure that foreign 

flagged vessels comply with IMO Tier III NOx limits while in U.S. waters. Tier I and Tier II 

limits are global standards, while the Tier III standards apply only in NOx ECAs. Tier III NOx

limits will apply to all ships operating within a NOx ECA area constructed on or after 1 January 
22

2016 with engines over 130 kW. Table 3-2 shows the Annex VI adopted NOx emissions 

standards, which are set based on the engine’s maximum operating speed (number of rpm). 

The ECA also triggers IMO and US EPA low sulfur fuel requirements for vessels in U.S. waters. 

Table 3-3 shows the fuel sulfur content limits.

Table 3-3. MARPOL Annex VI Fuel Sulfur Limits Globally and Within a SOx ECA

Global Within SOx ECA

Effective

Date

Sulfur Fuel

Limits

Effective

Date

Sulfur Fuel 

Limits

2004 45,000 ppm 2005 15,000 ppm

2012 35,000 ppm 2010 10,000 ppm

2020* 5,000 ppm * 2015 1,000 ppm

* Subject to a feasibility review in 2018; may be delayed to 2025.

IMO has developed guidelines for the use of exhaust gas cleaning systems (EGCS), such as SOx

scrubbers, as an alternative to operating on lower sulfur fuel. These guidelines include a table of 

sulfur dioxide (SO2) limits intended to correspond with various fuel sulfur levels. For existing 

ECAs, the corresponding limit is 0.4 g SO2/kW-hr for a 1,000 ppm fuel sulfur limit. This limit is 

based on an assumed fuel consumption rate of 200 g/kW-hr and the assumption that all sulfur in 

the fuel is converted to SO2 in the exhaust. The IMO guidelines also allow for an alternative 

approach of basing the limit on a ratio of SO2 to CO2. This has the advantage of being easier to 

measure during in-use monitoring. In addition, this ratio holds more constant at lower loads than 

a brake-specific limit, which would approach infinity as power approaches zero. For the existing

15,000 ppm fuel sulfur limit in ECAs, an SO2 (ppm)/CO2 (%) limit of 65 was developed. The 

equivalent limit for a 1,000 ppm fuel sulfur level is 4.0 SO2 (ppm)/CO2 (%).

In summary, a 0.1 percent low sulfur fuel requirement applies to all ships entering an ECA after 

January 1, 2015. Prior to this date and since 2010, ships were required to use a fuel with no more 

than 1 percent sulfur content. Additionally Tier III NOx emission standards that apply only to 

new ship constructions (and major engine rebuilds) will become effective in 2016.

3.2 Major Compliance Strategies

This section details some of the major compliance strategies available for the OGVs traveling 

within the North American and U.S. Caribbean ECAs. The following section mentions some 

additional technologies that are not expected to have significant early market penetration.

3.2.1 Strategy A – Exhaust Controls

Emission control technologies that can be used on C3 MDEs are limited. In addition to using 

distillate fuel to meet the fuel sulfur content limit in the ECA, one available option is to use a 

SOx scrubber. For meeting the NOx emission limits required in the North American ECA, 

selective catalytic reduction (SCR) was the control technology that EPA envisioned would be 

used to meet the Tier 4 emission standards. The following discussion describes these two control 

technologies.
23

3.2.1.1 Compliance with sulfur limits

Currently most OGVs use residual fuel as the main component in their main propulsion engines

because this fuel is relatively inexpensive and has a good energy density. Residual fuels typically 

are composed of heavy and very heavy hydrocarbons and can contain contaminants such as 

heavy metals and sulfur compounds. If the vessel does not employ a control technology, such as 

a sulfur scrubber, it will most likely operate using a marine distillate fuel while in an ECA in 

order to meet the sulfur emission requirements.

The SOx scrubbers are capable of removing up to 95 percent of SOx from ship exhaust using the 

available seawater to absorb SOx. The SOx scrubbers have been widely used in stationary source

applications for SOx reduction. In the stationary source applications, lime or caustic soda are 

typically used to neutralize the sulfuric acid in the water. While SOx scrubbers are not widely 

used on OGVs, there have been prototype installations to demonstrate their viability (e.g., the 

Krystallon systems installed on the P&O ferry Pride of Kent and the Holland America Line

cruise ship the ms Zaandam). These demonstrations have shown scrubbers can replace and fit 

into the space occupied by the exhaust silencer units and can work well in marine applications.

There are two main scrubber technologies for OGVs. The first is an open-loop design, which 

uses seawater as exhaust washwater and discharges the treated washwater back to the sea. Such 

open loop designs are also referred to as seawater scrubbers. In a seawater scrubber, the exhaust 

gases are brought into contact with seawater, either through spraying seawater into the exhaust 

stream or routing the exhaust gases through a water bath. The SO2 in the exhaust reacts with 

oxygen to produce sulfur trioxide (SO3) which then reacts with water to form sulfuric acid. The 

aqueous sulfuric acid then reacts with carbonate and other salts in the seawater to form solid 

sulfates which may be removed from the exhaust. The washwater is then treated to remove solids 

and raise the pH prior to its discharge back to the sea. The solids are collected as sludge and held 

for proper disposal ashore.

A second type of SOx scrubber uses a closed-loop design and is also feasible for use on marine

vessels. In a closed-loop system, fresh water is used as washwater, and caustic soda is injected 

into the washwater to neutralize the sulfur in the exhaust. A small portion of the washwater is 

bled off and treated to remove sludge, which is held and disposed of at port, as with the openloop design. The treated effluent is held onboard or discharged at open sea. Additional fresh 

water is added to the system as needed. While this design is not completely closed-loop, it can be 

operated in zero discharge mode for periods of time.

Water-soluble components of the exhaust gas, such as SO2, SO3, and NO2, form sulfates and 

nitrates that are dissolved into the discharge water. Scrubber washwater also includes suspended 

solids, heavy metals, hydrocarbons and polycyclic aromatic hydrocarbons (PAH). Before the

scrubber water is discharged, several approaches are available to process the scrubber water to 

remove solid particles. Heavier particles may be trapped in a settling or sludge tank for disposal. 

The removal process may include cyclone technology similar to that used to separate water from

residual fuel prior to delivery to the engine. Sludge separated from the scrubber water would be 

stored on board until it is disposed of at proper facilities. The IMO guidelines for the use of

exhaust gas cleaning devices such as SOx scrubbers recommended monitoring and water 

discharge practices. The washwater should be continuously monitored for pH, PAHs, and 

turbidity. Further, the IMO guidance includes limits for these same measurements, as well as 
24

nitrate content when washwater is discharged in ports, harbors or estuaries. Finally, the IMO 

guidance recommends that washwater residue (sludge) be delivered ashore to adequate reception 

facilities and not discharged to the sea or burned on board. Any discharges directly into U.S.

waters may be subject to Clean Water Act (CWA) or other U.S. regulation. To the extent that 

the air pollution control technology results in a wastewater discharge, such discharge will require 

a permit under the CWA’s National Pollutant Discharge Elimination System (NPDES) permit 

program.

Achieving a reduction of sulfur by using a wet scrubber means increasing power usage

significantly due to the use of pumped water, which indirectly results in an increase in other 

pollutant emissions associated with power production (e.g., GHGs).

3.2.1.2 Compliance with Tier 3 emission standards – SCR system

Among presently available after-treatment technologies, the urea-based Selective Catalytic 

Reduction (SCR) system represents the most mature and available solution to meet the marine 

engine Tier 3 NOx emissions standards. An SCR uses a catalyst to chemically reduce NOx to 

nitrogen using urea as a reagent in the presence of high-temperature exhaust gases. The SCR

technology is compatible with higher sulfur fuels and may be equipped with a soot blower to 

remove particulate matter. The SCR systems require intermediate inspections approximately 

every 2.5 years and full inspections every five years. Because heavy metals deposit on the 

catalysts over time, the catalyst disposal process has created an industry to regenerate spent 

catalysts and reintroduce them into the supply chain. The useful life of a marine SCR catalyst 

can be five to six years, and manufacturers typically guarantee catalysts for up to 16,000 hours of 

service.21 For vessels operating only part of the time within ECAs, the catalyst lifetime may be 

extended, in particular where 0.1% sulfur fuel is available.

Like many pollution control systems, the operation of SCR can be sensitive to engine exhaust 

temperature. Common practices of slow steaming could potentially contribute to SCR 

operational issues with low-load operation. Marine SCR applications have been designed to 

operate over a range of exhaust temperatures depending on fuel type, engine and catalyst design, 

and operating conditions. General minimum operating temperature ranges are between 260°C 

and 340°C, but systems may operate at lower temperatures for limited times. For marine engines, 

a variety of strategies are under development to expand the range of operating load conditions 

under which the SCR system functions normally. Exhaust gas temperatures can be boosted by

several means, including:

 Reducing the amount of air and using a system to preheat the exhaust before entry into 

the SCR system; 

 Adjusting injection timing; 

 Bypassing part of the exhaust through a heated hydrolysis catalyst which allows urea to 

be injected at exhaust gas temperatures as low as 150°C; 

 Heating the urea dosing system prior to injection to maximize efficiency; and, 

 

21 Wärtsilä, “IMO Tier III Solutions for Wärtsilä 2-Stroke, Engines—Selective Catalytic Reduction (SCR),” 2011.
25

 For ships with multiple engines, shutting down one or more engines and running fewer 

engines at higher power. 

In another approach, at low loads, a portion of the catalyst can be bypassed by condensing the 

exhaust gas volume and forcing it through a smaller catalyst volume, maintaining turbulent flow 

and high catalyst temperature. Hitachi Zosen and MAN Diesel recently completed a successful 

sea trial with SCR systems in use to operate at a 10 percent engine load.22

Engine architecture may allow specific strategies. For four-stroke engines, the SCR catalyst can 

be mounted after the turbocharger. Four-stroke engines have also been developed which allow

SCR operation down to a 10–15 percent load. For two-stroke engines, the catalyst is mounted 

before the turbocharger inlet where the exhaust gas temperatures and pressures are higher. This 

has the added benefit of allowing the system to be operated using a smaller reactor. For twostroke engines, the placement of the SCR catalysts upstream of the exhaust turbine can ensure 

effective NOx reduction down to at least a 25-percent load. The “pre-turbocharger” SCR 

approach has been used successfully for over a decade on vessels equipped with slow-speed 

engines that required NOx control when operating at low loads near coastal areas. Recently, 

Hitachi Zosen certified an engine design utilizing a compact, high-pressure, high-temperature 

SCR system that meets Tier III standards while producing minimal additional CO2 emissions 

down to a 10-percent engine load.22

Overall, demand for urea for marine SCR applications is expected to be modest compared to 

other applications. The EPA estimates that urea use in the North American NOx ECA will total 

approximately 454,000 tons in 2020 (which would constitute less than 10 percent of the 2015 onroad consumption levels and an even smaller fraction of projected 2020 use).

23 Because road 

transport is expected to consume no more than 5 percent of 2020 worldwide urea production, this 

suggests that marine urea consumption in 2020 will be significantly less than 1 percent of the

worldwide total. Because the IMO regulation applies to new builds only (and to new engines 

installed on existing vessels), there should be adequate time for a urea supply chain to develop 

further in the future as marine SCR application slowly grows in step with the global vessel newbuilding program.

In October 2013, Caterpillar Marine announced that their C280 and 3516C models will meet 

EPA Tier 4 using SCR after-treatment systems.24 Cummins Marine already uses SCR and 

indicates their planned use for higher horsepower marine engines to achieve EPA’s Tier 4

standards. Other engine manufacturers have also indicated SCR as their planned approach to 

compliance.

 

22 Hitachi Zosen Corporation. “First ever marine vessel equipped with Pre-Turbo SCR system achieves compliance 

with Tier III NOx emission standards certified by Nippon Kaiji Kyokai.” 6 December 2011. Last accessed from 

http://www.hitachizosen.co.jp/english/news/2011/12/000568.html on January 22, 2015.

23 U.S. Environmental Protection Agency. Proposal to designate an Emission Control Area for Nitrogen Oxides, 

Sulfur Oxides, and Particulate Matter: Technical Support Document. EPA-420-R-09-007. Last accessed from 

http://www.epa.gov/nonroad/marine/ci/420r09007-chap5.pdf on January 19, 2015.

24 Marine Log. “Cat unveils Tier 4 marine engines.” 8 October 2013. Last accessed from 

http://www.marinelog.com/index.php?option=com_k2&view=item&id=5236:cat-unveils-tier-4-marineengines&Itemid=231 on January 22, 2015.
26

3.2.2 Strategy B – LNG-fueled vessels

As the shipping industry considers alternatives to HFO, part of the market will shift toward 

marine gas oil (MGO) and part toward LNG or other alternative fuels. Marine vessels equipped 

with scrubbers will retain the advantage of using lower‐priced HFO. Shipping that takes place 

outside ECA areas might choose HFO or low‐sulfur fuel oil (LSFO) depending on future global 

regulations. Ships operating partly in ECA areas will likely choose MGO as a compliance fuel. 

Heavy shipping within ECA areas, however, might provide enough incentive for a complete shift 

to LNG.

LNG-fueled engines burn cleaner and do not require after-treatment or specialized NOx

abatement measures to meet EPA Tier 4 (IMO Tier III). The potential lack of emission controls,

in conjunction with its significantly lower fuel cost, makes LNG an attractive option for 

compliance. The only large ships currently using LNG as a fuel on international voyages are 

LNG cargo carriers. For LNG to become an attractive fuel for the majority of ships, a global 

network of LNG bunkering terminals must be established. If not, LNG‐fueled ships will be 

limited to coastal trades where LNG bunkering networks are established.

The ability of LNG engines to meet Tier III NOx requirements depends on the engine 

technology. While all LNG engine manufacturers do not yet have Tier III-compliant offerings, 

they are all likely to have introduced Tier III compliant engines within a few years.25 The marine 

LNG engines currently available are almost exclusively dual-fuel engines that use a pilot fuel 

(MDO) to provide an ignition source for natural gas in the engine’s cylinders. The amount of 

pilot fuel required varies based on engine technology, engine load, and pilot fuel quality. While 

some engines need a load of at least 30 percent before they can burn natural gas,26 one of the 

most recent engine introductions can burn gas at any load, with pilot fuel energy consumption 

that is around 2 percent of the primary fuel energy consumption.27 For the purposes of fuel 

demand modeling, it is reasonable to assume that virtually all LNG new-builds operating in an 

ECA will use dual-fuel engine designs that are equivalent to the current most advanced designs 

that meet Tier III without the addition of SCR, are able to burn natural gas at all engine loads, 

and have pilot fuel use equivalent to 2 percent of the total engine energy use.

When LNG is considered with its storage and support systems, the volumetric energy density of 

LNG can be up to three times higher than diesel fuels. This space penalty can be too large to 

 

25 The most recent dual-fuel LNG marine engines introductions by both Wärtsilä and MAN meet Tier III without 

SCR:

Hagedorn, M. “LNG Engines: Specifications and Economics.” Presented at LNG shipping Rostock. October 13, 

2014. Last accessed from 

http://www.golng.eu/files/Main/20141017/Rostock/LNG%20Shipping%20Session%20II%20-

%20LNG%20Engines-Specifications%20and%20Economics-%20W%C3%A4rtsil%C3%A4,Ship%20Power%20-

%20Hagedorn.pdf on January 22, 2015.

The Motorship. “MAN goes for Tier III compliance.” 30 October 2014. Last accessed from 

http://www.motorship.com/news101/engines-and-propulsion/man-goes-for-tier-iii-compliance on 22 January 2015.

26MAN Diesel. “ME-GI Dual Fuel MAN B&W Engines: A Technical, Operational and Cost-effective Solution for 

Ships Fuelled by Gas.” Last accessed from 

http://www.dma.dk/themes/LNGinfrastructureproject/Documents/Bunkering%20operations%20and%20ship%20pro

pulsion/ME-GI%20Dual%20Fuel%20MAN%20Engines.pdf on 22 January 2015.

27 Stiefel, R. “Wärtsilä awarded milestone order to supply 2-stroke dual-fuel engines for large LNG carriers.” Press 

release on 9 September 2014. Last accessed from http://www.wartsila.com/en/press-releases/wartsila-awardedmilestone-order-to-supply-2-stroke-dual-fuel-engines-for-large-lng-carriers on 22 January 2015.
27

overcome for many vessels. If technically feasible, a total ownership cost analysis is needed to 

evaluate whether this approach would result in a low enough payback period to justify the higher 

investment cost.

It has been suggested that about half the commercial fleet of marine vessels could be converted 

to LNG. However, these conversions would not involve the largest vessels and likely not OGVs. 

Thus, in terms of amount of converted fuel use, the percentage would be much lower than half 

the fleet. One estimate on marine LNG consumption in 2020 is 2.4 megatonnes (MT) of LNG in 

2020. 28

A report from the IEA Advanced Motor Fuels Implementation Agreement29 stated:

“A major concern with LNG is the possibility for de‐bunkering (or emptying the 

fuel tanks). This step is necessary when a ship is to be anchored for an extended 

period of time. Unless special LNG de‐bunkering facilities are available in the 

port, the gas would boil off, causing huge methane losses to the atmosphere. In 

the case of grounding accidents, a technique for de-bunkering would also be 

necessary. Another concern is the pressure increase when consumption occurs 

below the natural boil‐off rate, which will happen if there is no re‐liquefaction 

plan available onboard. Re‐liquefaction of boil‐off gas requires about 0.8 kWh/kg 

gas. One large LNG carrier, such as Qatar Q‐max, requires 5–6 MW of re‐

liquefaction power, corresponding to a boil‐off rate of 8 tons/hour.

“A third concern that needs to be addressed with LNG conversions is methane 

slip from larger marine engines burning the gas. Methane slip will occur, 

especially on four‐stroke, dual‐fuel engines (Figure 13 [not shown]), partly from 

the scavenging process in the cylinder and partly from the ventilation from the 

crank case, which is being led to the atmosphere. In addition, there is some 

uncertainty as to whether future regulations will allow LNG tanks to be situated 

directly below the outfitting/accommodation of the ship. If not, this constraint 

could cause difficulties in retrofitting certain ships.”

3.2.3 Strategy C – Engine-based controls

Engine modifications to meet Tier III emission levels will most likely include a higher 

percentage of common rail fuel injection systems coupled with the use of two-stage 

turbocharging and electronic valving. Engine manufacturers estimate that practically all slowspeed engines and 80 percent of medium-speed engines will use common rail fuel injection. Two 

stage turbocharging will probably be installed on at least 70 percent of all engines produced to 

meet Tier III emission levels. Electronically (hydraulically) actuated intake and exhaust valves 

for medium-speed engines and electronically actuated exhaust valves for slow-speed engines are 

necessary to accommodate two-stage turbocharging.30

 

28 “North European LNG Infrastructure Project,” Danish Maritime Authority, accessed at the following link:

http://www.dma.dk/themes/LNGinfrastructureproject/Sider/Papersandpresentations.aspx

29 “Alternative Fuels for Marine Applications,” A report from the IEA Advanced Motor Fuels Implementation 

Agreement, May 2013. Last accessed from http://www.ieaamf.org/app/webroot/files/file/Annex%20Reports/AMF_Annex_41.pdf on January 18, 2015. 

30 U.S. Environmental Protection Agency, Costs of Emission Reduction Technologies for Category 3 Marine 

Engines. Final Report EPA-420-R-09-008. May 2009.
28

The on-engine approach requires the addition of an Exhaust Gas Recirculation (EGR) system. 

EGR is a mature technology that has widely been used for on-road engines. By using EGR, a 

portion of the exhaust gas is recirculated back to the engine cylinders. The recirculated gases 

lower the oxygen content at the engine intake resulting in lower combustion temperatures and 

less thermal NOx production. A heat exchanger is used to cool the recirculated exhaust air before

entering the air intakes. The net of effect of this recirculated air is a less efficient combustion 

process due to the lower combustion pressure. Consequently EGR usage presents a fuel 

consumption penalty. To offset the lower combustion pressure, manufacturers are implementing 

improved engine designs such as new generation common rail direct fuel injection systems with 

higher pressures (15,000-40,000 pounds per square inch). The common rail allows finer 

electronic control over the fuel injection to provide multiple controlled injections per stroke. The 

fuel is further atomized to allow improved combustion. EGR allows the engine user to avoid the 

use of a urea-based SCR system, but it adds weight and complexity on the engine. In addition, 

EGR requires higher quality fuel with lower sulfur content for proper operation. Though not an 

issue in the U.S., this fuel requirement could create complications for vessels operating abroad 

where low sulfur diesel may not be available. 

3.3 Other Compliance Options Considered

Alternative fuels are being developed as replacements to marine oil to help with compliance with 

the low sulfur fuel standard and to reduce operating costs in the long run. Quadrise Canada has 

developed a low‐cost alternative to heavy fuel oil called Multiphase Superfine Atomized Residue 

Synthetic Fuel Oil (MSAR® SFOTM).31 The MSAR® SFOTM fuel technology renders heavy 

hydrocarbons easier to use by producing a low-viscosity fuel oil using water instead of expensive 

oil‐based diluents, and also produces a superior fuel with enhanced combustion features. The 

process involves injecting smaller fuel droplets in a stable water‐based emulsion into the 

cylinder, resulting in a complete combustion that produces lower NOx and particulate exhaust gas 

emissions. MSAR® SFOTM can be air-atomized into 80-micron drops that contain thousands of 

small 5-micron fuel droplets that have seventeen times more surface area than a standard steam 

atomized drop. This property provides a much larger surface for contacting the combustion air 

with the fuel, leading to the need for low excess oxygen, quicker and more complete combustion, 

and less char formation (lower particulate emissions). In addition, since the fuel contains liquid 

water, the combustion temperature is lower, leading to lower NOx formation.

Biofuels are one of the options to lower carbon intensity in the propulsion of ships and to reduce 

the effect of emissions to local air quality. However, the shipping sector is still in a very early 

stage of orientation towards biofuels. Currently no significant consumption of biofuels for 

shipping is taking place. However, there are R&D initiatives32 in Europe that are investigating 

the possibilities. For example, under the TEN-T Priority Project 21: Motorways of the Seas,

33

 

31 Quadrise Canada Corporation. “Low Cost Alternative Fuel (MSAR ® SFOTM).” Last accessed from 

http://www.quadrisecanada.com/fcs-low-cost.php on January 22, 2015.

32 European Biofuels Technology Platform. “Use of Biofuels in Shipping.” Last accessed from 

http://www.biofuelstp.eu/shipping-biofuels.html#proj on January 22, 2015.

33 Innovation and Networks Executive Agency, European Commission. “Priority Project 21: Motorways of the 

Sea.” Last accessed from http://inea.ec.europa.eu/en/ten-t/tent_projects/30_priority_projects/priority_project_21/priority_project_21.htm on January 22, 2015.
29

pilot tests on methanol as a marine fuel of the future34 are currently being carried out. 

Biomethanol potentially could be used as well as methanol from fossil sources. These potential 

solutions should be followed in the future as they may become viable options.

Other potential NOx emission reduction techniques that may have some merit include water 

injection, which could consist of the introduction of water into the combustion chamber either 

through fumigation or as fuel emulsions, or direct water injection. Another alternative is to use 

EGR and a Humid Air Motor (HAM) system, a combination that resulted in NOx emission 

reductions approaching those for SCR.35

3.4 Compliance Cost Issues

As discussed in the preceding sections, as of January 2015, vessels operating in designated ECAs 

and in regions with ECA-equivalent regulations are required to use fuels with sulfur levels that 

do not exceed 0.1% or use exhaust treatment technologies (i.e., scrubbers) to remove SOx. 

Options for meeting these regulations include the use of low-sulfur MDO, the use of HFO with 

scrubbers, or the use of LNG (a naturally low-sulfur fuel). Beginning in 2016, new-build vessels 

operating in the North American ECA will additionally need to meet stringent IMO Tier III (or 

EPA Tier 4) NOx regulations which require use of after-treatment technologies (i.e., SCR or 

EGR) for MDO and HFO combustion. It is assumed that the 2016 new-build LNG engines will 

be able to meet Tier III without the use of SCR.

Compliance with these new emission requirements will raise operating costs for ship owners and 

operators in the North American ECA as they upgrade their aging shipping fleet with new ships.

The new ships will have more complicated fuel systems, potentially post-treatment control 

equipment, and more expensive low sulfur fuels. Existing ships that do not have dual tanks may 

require retrofits with dual fossil fuel systems to allow fuel switching when they enter an ECA.

In general, the costs to ship owners for complying with the 2015 sulfur fuel limits are 

substantially greater (e.g., at least ten-fold) than the additional costs for implementation of 

strategies to comply with the lower NOx limits dictated by IMO’s Tier III standards (equivalent 

to EPA Tier 4 NOx standards). It should be noted that the confidence that can be placed in 

economic feasibility comparisons of marine compliance strategies at the present time is 

substantially limited by the immaturity of the technologies associated with some of the key 

strategies that were identified in the previous section. 

The low sulfur fuel ECA requirement applies to all ships entering an ECA after January 1, 2015, 

but the Tier III NOx emission standards only apply to new ship builds (and major engine 

rebuilds) that are initiated starting in 2016. Consequently some studies assessing compliance 

strategies have assumed that fuel selections will essentially be determined based on sulfur 

compliance strategies (i.e., low sulfur MDO, scrubbers, or LNG).36

 

34 Innovation and Networks Executive Agency, European Commission. “2012-EU-21017-S Methanol: The 

marine fuel of the future.” Last accessed from http://inea.ec.europa.eu/en/ten-t/ten-t_projects/tent_projects_by_country/multi_country/2012-eu-21017-s.htm on January 22, 2015.

35 Presentation of Ulf Hagstrom, Marine Superintendent, Technical sector, Viking Line Apb, “Humid Air Motor 

(HAM) and Selective Catalytic Reduction (SCR) Viking Line,” at Swedish Maritime Administration 

Symposium/Workshop on Air Pollution from Ships (May 24-26, 2005)

36 Danish Ministry of the Environment, 2012. “Economic Impact Assessment of a NOx Emission Control Area in the 

North Sea.” http://www2.mst.dk/Udgiv/publications/2012/06/978-87-92903-20-4.pdf
30

Appendix C briefly describes current (i.e., 2014/2015) perspectives on compliance strategy 

selection, provides summary results of studies that examine and estimate future adoption of

scrubbers and LNG technologies, and concludes with a summary of recently published cost 

analyses of the compliance strategies. Some costing information was available for smaller ships 

(engine sizes around 10,000 kW), but more information (and possibly vendor quotes) would be 

necessary to understand the costs to ships as large as the average container ships (engine sizes 

around 36,000 kW in Table 2-2). Because some technologies are still relatively new, the costs 

are expected to decrease with market penetration.
31

4 Projections to Future Years

Section 2 discussed the method for determining fuel consumed by OGVs traveling in the North 

American ECA based on port calls in 2012. However, the IMO protocol requirements for ships 

traveling in the North American ECA did not take effect until January 1, 2015. In addition, 

shipping patterns change with time, and newer vessels will be more efficient than older ones. 

This section explores a method that NEMS model developers could use to estimate future fuel 

usage within the North American and U.S. Caribbean ECAs.

Because the average age of ships calling on the U.S. between 2006 and 2011 was 10.5 years 

based on MARAD data,

37 the fleet turnover rate of 9.5 percent each year was considered rapid. 

Older ships have been routed to non-U.S. ports after the service life to the U.S. ended; the world 

fleet’s average age in 2014 was 20.2 years.38 Ships built for use in the North American ECA 

after 2015 must meet at least one of the compliance options, but older ships without scrubbers 

were assumed to opt against retrofit technologies in favor of either operation with MGO fuel or 

operation elsewhere in the world outside the North American ECA.39 This assumption may result 

in higher MGO and lower IFO fuel use from 2015 to 2025 than would an approach that considers 

retrofitted units as a significant fraction of the fleet.

4.1 Increased Efficiency of New Vessels

As mentioned in the preceding paragraph, the fleet turnover (FLEETTO) variable (default value 

of 9.5 percent per year) was computed from MARAD data to represent the rate of introduction of 

new vessels into the fleet moving through the North American ECA. The new vessels are 

assumed to be more efficient than their predecessors.

Some technologies that the International Council on Clean Transportation (ICCT) suggests will 

reduce fuel use (and CO2 emissions)40 appear in Table 4-1. Under the implementation of the 

mandatory regulations on Energy Efficiency for Ships in MARPOL Annex VI, it is expected that 

ship efficiency will result in an average 1 percent increase in ship operating efficiency each year 

above a 2000-2010 reference case.41

 

37 Vessel Calls Snapshot, 2011, Released: March 2013, Revised: November 2013, Office of Policy and Plans, 

Maritime Administration, U.S. Department of Transportation, www.marad.dot.gov/data_statistics

38 United Nations Conference on Trade and Development. Review of Maritime Transport 2014. ISBN 978-92-1-

112878-9. Last accessed from http://unctad.org/en/PublicationsLibrary/rmt2014_en.pdf on March 5, 2015.

39 Ships built on or before 1 August 2011 that are powered by propulsion boilers that were not originally designed 

for continued operation on marine distillate fuel or natural gas are exempted from the ECA regulations until 1 

January 2020 (according to IMO -RESOLUTION MEPC.202(62)- Adopted on 15 July 2011). In addition, 

conditional waivers granting additional time to comply with the ECA regulations have been issued by the U.S. EPA 

and U.S. Coast Guard to Totem Ocean Trailer Express and to Horizon Lines (Horizon Lines is being divided for sale 

to Matson and to Pasha Group). Totem, Horizon Lines and Matson represent a majority of the U.S. container ship 

fleet.

40 Wang, H. and N. Lutsey. “Long-term potential for increased shipping efficiency through the adoption of industryleading practices.” 2013 International Council on Clean Transportation. www.theicct.org

41 International Maritime Organization. “Technical and Operational Measures.” Last accessed from 

http://www.imo.org/OurWork/Environment/PollutionPrevention/AirPollution/Pages/Technical-and-OperationalMeasures.aspx on January 22, 2015.
32

Table 4-1. ICCT List of Potential Fuel Reduction Technologies

Area Technology Potential CO2 and Fuel Use Reduction

Engine Efficiency Engine controls

Engine common rail

Waste heat recovery

Design speed reduction

0-1%

0-1%

6-8%

10-30%

Thrust efficiency Propeller polishing

Propeller upgrade

Rudder

3-8%

1-3%

2-6%

Hydrodynamics Hull cleaning

Hull coating

Water flow optimization

1-10%

1-5%

1-4%

Aerodynamics Air lubrication

Wind engine

Kite

5-15%

3-12%

2-10%

Auxiliary power Auxiliary engine efficiency

Efficient pumps, fans

Efficient lighting

Solar panels

1-2%

0-1%

0-1%

0-3%

Operational Weather routing

Autopilot upgrade

Operational speed 

reduction

1-4%

1-3%

10-30%

This improved efficiency was translated in the computations to be expressed in new fleet vessels 

by calculating the 1 percent improvement per year for the average age of a vessel since the 2012 

baseline. The EFFINC variable (default of 1 percent per year) can be used with the constant

FLEETTO variable to compute the fuel consumption associated with a new fleet for a different 

year (YR):

FUELCONS'YR,class,CD = fuel by 2012 fleet + fuel by post-2012 fleet

FUELCONS'YR,class,CD = FUELCONS2012,class,CD×maximum[0,1-(YR-2012)*FLEETTO]

+ FUELCONS2012,class,CD×{1- maximum[0,1-(YR-2012)*FLEETTO]}

× [1-EFFINC]^[(YR-2012)/2]

4.2 Changes in Shipping Demands

The variable FUELCONS'YR,class,CD in the previous section included an apostrophe because a 

second step to predicting the future fleet demands for total fuel consumption by a class is 

accounting for changes in market growth. The NEMS market growth numbers on imports and 

exports might vary by U.S. Census Division but are more easily collected on a national basis. 

Table 4-2 shares some baseline 2012 estimates from the ACOE about shipments to indicate 

whether the larger markets are by imports or exports.
33

Table 4-2. Weight (Million Short Tons) Transported in 2012 Through U.S. Waters Now 

under the North American ECA42

Commodity

Foreign 

Inbound

Foreign 

Outbound

Domestic 

Coastwis

e

Associated 

Vessel Class

Total petroleum and petroleum 

products

482 151 110 Energy tankers

Other chemicals and related products 35 54 9 Non-energy 

tankers

Total all manufactured equipment, 

machinery and products + total 

primary manufactured goods -

vehicles and parts

128 41 16 Containers

Hydrocarbon and petrol gases, 

liquefied and gaseous

5.7 6.3 0.06 Gas (LNG)

Hydrocarbon and petrol gases, 

liquefied and gaseous

5.7 6.3 0.06 Gas (LPG)

Vehicles and parts 12 6 0.8 Roll-on/roll-off

Total coal + petroleum coke 12 156 5 Bulk - Energy

Total food and farm products 41 155 4 Bulk – Nonenergy

Total all manufactured equipment, 

machinery and products + total 

primary manufactured goods -

Vehicles and parts

128 41 16 General cargo

Examination of Table 4-2 indicates that imports might represent the larger ECA activity for 

energy tankers, container ships, roll-on/roll-off vessels, and general cargo. Fuel usage from these 

four vessel classes represents 85 percent of the 2012 energy profile from Section 2.

NEMS predicts imports and exports of the Table 4-2 commodities to change at different rates for 

future years, so the recommended approach is to distinguish these commodities using some 

parameters associated with NEMS. For energy commodities, the growth rates for the market 

imports/exports will change based on the AEO scenarios. Table 4-3 shows how the AEO 2014 

reference case predicts that energy commodities might change with time.

Table 4-3. Energy Commodity Changes in the AEO 2014 Reference Case

Year

Crude Oil Gross Imports 

(million bbl per day)

LNG Exports 

(trillion cf)

Steam Coal Export 

(million short tons)

2012 8.49 0.03 55.9

 

42 Table 2-1 in “Waterborne Commerce of the United States: Calendar Year 2012 Part 5—National Summaries.” 

U.S. Army Corps of Engineers. Last downloaded from http://www.navigationdatacenter.us/wcsc/pdf/wcusnatl12.pdf

on January 14, 2015.
34

Year

Crude Oil Gross Imports 

(million bbl per day)

LNG Exports 

(trillion cf)

Steam Coal Export 

(million short tons)

2013 7.48 0.01 49.6

2014 6.59 0.01 45

2015 6.31 0.11 47

2016 5.92 0.31 48.9

2017 5.97 0.76 51.1

2018 5.96 1.26 53.4

2019 5.91 1.77 53.4

2020 5.94 2.08 55.2

2021 6.04 2.32 55.4

2022 6.08 2.32 57

2023 6.11 2.52 58.8

2024 6.17 2.72 60.5

2025 6.18 2.72 62.3

2026 6.32 2.92 63.7

2027 6.46 3.12 63.6

2028 6.58 3.32 63.5

2029 6.7 3.5 67.4

2030 6.77 3.52 73.6

2031 6.91 3.52 77.3

2032 6.99 3.52 77.9

2033 7.02 3.52 78.5

2034 7.12 3.52 81.4

2035 7.27 3.52 83.8

2036 7.43 3.52 82.6

2037 7.53 3.52 74.2

2038 7.74 3.52 76.1

2039 7.79 3.52 83.7

2040 7.87 3.52 86.9

Therefore, the fuel consumption from the various vessel classes may be directly related to AEO 

2014 scenario outputs. As an example, the calculations for energy tankers could be based on the 

projections of petroleum imports:

FUELCONSYR,energy tankers,CD = FUELCONS’YR,energy tankers,CD ×[MGPETRYR / MGPETR2012]

where MGPETRYR represents the imports of “Petroleum and Products” in the Macroeconomic 

Activity Module. A list of NEMS variables that might be associated with the different vessel 

types is presented in Table 4-4.

Another option for the non-energy vessel classes would be to base growth rates on population 

growth rates within the U.S. Census Divisions. The U.S. Census last predicted national growth to 

rise from 321 million in 2015 up to 380 million by 2040.43

 

43 U.S. Census Bureau. “Population Projections: 2014 National Population Projections: Summary Tables.” Last 

accessed from http://www.census.gov/population/projections/data/national/2014/summarytables.html on January 14,

2015. 
35
36

Table 4-4. Potential NEMS Variables That Could Indicate Fleet Growth in Future Years

Vessel Class Parameter Module Parameter Description

Energy tankers MGPETR Macroeconomic 

Activity Module

Real Imports of “Petroleum and 

Products”44

Non-energy 

tankers

XGINR Macroeconomic 

Activity Module

Real Exports of “Industrial materials and 

supplies”

Containers MGCR Macroeconomic 

Activity Module

Real Imports of “Consumer goods except 

motor vehicles”

Gas (LNG) NGLEXP Liquid Fuels 

Market Module

Natural Gas Liquid export

Gas (LPG) NGLEXP Liquid Fuels 

Market Module

Propane export

Roll-on/roll-off MGAUTOR Macroeconomic 

Activity Module

Real imports of “Motor vehicles & parts”

Bulk - Energy -- Coal distribution 

submodule in 

Coal Market 

Module

"CEXPRT" generates reports from the 

export portion of the linear program (plus 

petroleum coke exports)

Bulk – NonenergyXGFFBR Macroeconomic 

Activity Module

Real exports of “Foods, feeds and 

beverages”

General cargo MGKR Macroeconomic 

Activity Module

Real imports of “Capital goods except 

motor vehicles”

4.3 Compliance Choices

The final element in the determination of fuel projections is the allocation of energy consumption 

among the different fuel choices. Before describing the resultant profiles, several assumptions 

about the projections are discussed below:

1. Protocol takes effect: 

a. The North American ECA went into effect on January 1, 2015. It requires 

existing ships to either burn fuel containing a maximum of 0.1% sulfur or to use 

scrubbers to remove the sulfur emissions.

b. On January 1, 2020 the IMO will require the sulfur content of fuel used outside of 

the ECA to be reduced to 0.5% (a possible five-year delay is possible and would 

be based on a 2018 re-evaluation).

2. Technology Introduction Year to Fleet

a. EPA Tier 3: On January 1, 2016 all new build ship engines used in the ECA are 

required to be EPA Tier 3 compliant.

b. LNG Vessels enter U.S. Fleet: In 2015 the first LNG-fueled container ship is due 

to become operational.

 

44 NEMS also tracks ethanol and biodiesel imports and exports. These variables could be added to the petroleum 

values to track total activity projections of energy tankers.
37

c. Scrubber: While the exact date that emission scrubber technology was installed on 

commercial freight ships was not reported, DNV45 estimated in a 2012 report that

30-40 percent of all new builds will have emission scrubber technology installed 

by 2016. After 2016, all new ships that consume fuel oil and will operate within 

the ECA are required to have scrubber and other emission control technologies

installed. 

3. Conventional engine using IFO: Prior to 2015 ships calling on the U.S. could operate on 

fuel used internationally and their ships did not require scrubbers to remove sulfur 

emissions. Nearly all large OGVs were powered by slow speed diesel engines that burned 

IFO 380 or IFO 180. IFO is 88-98 percent residual fuel oil with 2-12 percent distillate 

added to achieve proper viscosity. IFO for use outside an ECA has a maximum sulfur 

content of 3.5%. 

4. Conventional engine using MGO: Existing ships can continue to operate in the ECA 

without scrubbers if they use MGO as their fuel oil. 

5. Conventional engine with operating scrubber using IFO: Ships in existence before 2016 

can continue to use a conventional engine and burn IFO within the ECA if the ship has 

installed sulfur scrubbers. Ships that enter service after January 1, 2016 must be equipped 

with sulfur scrubbers and NOx controls technology.

The projection that new ships built after 2015 would install and operate scrubbers instead of 

burning MGO in the ECAs is based on a BIMCO study that presented the investment function 

for scrubbers versus MGO.46 Calculations conducted for this project show that container ships 

from Asia and Europe would spend 16-21 percent and 43-49 percent of their operating time on 

voyages within ECAs.47 The AEO 2014 reference case, high oil price case, and low oil price 

cases all showed high spreads between HFO and MGO prices after 2015 (over $600/metric ton), 

and the BIMCO summary indicated that such voyages and price spreads would justify the 

investment in scrubber technologies for new ships.48

These assumptions were used to build fleet profiles for the activity of OGVs within the North 

American ECA. The profiles appear in Table 4-5 for three scenarios developed by DNV.49 The 

first scenario estimated that, if the price if LNG was 10 percent above the price of HFO, that 7.5

to 9 percent of new builds would use LNG as their fuel. The second scenario estimated that, if 

the price of LNG was 30 percent below the price of HFO, that 13 percent of new builds would 

use LNG as their fuel. The third scenario estimated that, if LNG was 70 percent below the price 

of HFO, that 30 percent of new builds would use LNG as their fuel. All three scenarios assume 

that any subsidies for a particular fuel or technology have already been incorporated into the cost

comparison.

 

45 DNV, Report of Shipping 2020: http://www.dnv.nl/binaries/shipping%202020%20-%20final%20report_tcm141-

530559.pdf; last accessed on January 20, 2015.

46 “Business Case: Marine Gas Oil or Scrubbers When Operating in an ECA?” BIMCO. Published on April 25, 

2013. Last accessed from https://www.bimco.org/Reports/Market_Analysis/2013/0424_ECAStory.aspx on January 

22, 2015.

47 Calculations done for voyages from Shanghai to Los Angeles and from Rotterdam to New York/New Jersey.

48 Note that the BIMCO study reflects tanker ships, but similar curves could be derived for container ships.

49 DNV report shipping 2020; Det Norske Veritas; NO-1322 høvik, Norway; www.dnv.com
38
39

Table 4-5. Fleet Profiles of Compliance Strategies under Three Scenarios

Year

Conventional 

engine using 

IFO (includes 

vessels with 

non-operating 

scrubbers)

Conventional 

engine using 

MGO

LNG Price 10% 

above HFO Price

LNG Price 30% 

below HFO Price

LNG Price 70% 

below HFO Price

Conventional 

engine with 

operating 

scrubber using 

IFO

LNG 

engine

Conventional 

engine with 

operating 

scrubber using 

IFO

LNG 

engine

Conventional 

engine with 

operating 

scrubber using 

IFO

LNG 

engine

2012 100% -- -- -- -- -- -- --

2013 100% -- -- -- -- -- -- --

2014 100% -- -- -- -- -- -- --

2015 -- 90% 10% -- 10% -- 10% --

2016 -- 77% 22% 1% 22% 1% 20% 3%

2017 -- 64% 34% 1% 33% 2% 30% 6%

2018 -- 51% 46% 2% 45% 4% 40% 9%

2019 -- 39% 59% 3% 56% 5% 50% 11%

2020 -- 26% 71% 4% 68% 6% 60% 14%

2021 -- 13% 83% 4% 80% 7% 70% 17%

2022 -- -- 95% 5% 91% 9% 80% 20%

2023 -- -- 95% 5% 91% 9% 79% 21%

2024 -- -- 95% 5% 91% 9% 79% 21%

2025 -- -- 95% 5% 91% 9% 79% 21%

2026

and 

beyond

-- -- 93% 8% 87% 13% 70% 30%

Table 4-5 shows that engines with scrubbers are more prevalent in the fleets in 2022 through 

2025 than they are in years beyond that point. These high percentages occur because scrubbers 

were introduced to the new fleet before LNG vessels.

Scrubbers and other control devices do require energy, as do fuel chillers associated with the use 

of MGO. The model has been constructed to impose energy penalties for the use of MGO, LNG, 

and scrubbers. Such an energy penalty might also take the form of a decreased cargo footprint 

aboard vessels with the alternate fuels and control technologies. However, the energy penalties 

have not yet been well characterized and reported in the published literature. The energy 

penalties have been initially set to zero, except the penalty for scrubbers is set to 2 percent.

50,51

Designs are changing very rapidly with the introduction of these technologies aboard larger 

ships, so EIA should consider energy penalties for these systems that decrease over time.

 

50 ABS. Exhaust Gas Scrubber Systems: Status and Guidance. Last accessed from 

https://www.eagle.org/eagleExternalPortalWEB/ShowProperty/BEA%20Repository/References/Capability%20Broc

hures/ExhaustScrubbers on January 22, 2015.

51 “EffShip Project Final Seminar.” Published on 21 March 2013. Last downloaded from 

http://www.effship.com/PublicPresentations/Final_Seminar_2013-03-21/09_EffShip-Handout.pdf on January 16, 

2015.
40

An energy penalty for older LNG gas ships could be approximated because they use a forced 

natural gas boil-off from the cargo tanks in steam boilers to produce steam for steam turbines. A 

steam turbine propulsion system has an energy efficiency of about 28 percent compared to the 

approximately 50 percent for a conventional slow-speed diesel engine. However, the number of 

LNG ships calling on U.S. ports is very small compared to total vessel calls and quantifying the 

declining number of older LNG gas ships using steam turbine propulsion systems would not 

significantly impact the overall report projections.

4.4 Fuel Estimates

Total fuel consumptions in each Census Division were multiplied by the fleet profiles and energy 

penalty corrections to determine the amount of each fuel consumed (as billion Btu) within the 

North American and U.S. Caribbean ECAs for each Census Division:

MARFUELYR,CD,MFtype = FLTPROFYR,MFtype × (1 + ENPENMFtype)

× ∑ FUELCONSYR,class,CD

general cargo

class=energy tankers

where MARFUELYR,CD,MFtype = marine fuel consumed in ECA transit using MFtype fuel 

in year YR across Census Division CD

FLTPROFYR,MFtype = fraction of the fleet using MFtype fuel in year YR

ENPENMFType = energy penalty associated with MFtype fuel52

Using the scenario where the LNG price is 30 percent below the HFO price, Table 4-6 shows the 

marine fuels consumed in the North American and U.S. Caribbean ECAs in 2021. That year is 

the last one in which MGO fuel is likely to be used (Table 4-5).

Table 4-6. Total Fuel Consumed (Billion Btu) in North American and U.S. Caribbean 

ECAs in 2021 by Marine Fuel Type

Census Division IFO LNG MGO Total

New England 2,200 200 350 2,700

Middle Atlantic 12,000 1,100 1,800 14,000

Midwest - - - -

West North Central - - - -

South Atlantic 33,000 3,000 5,200 41,000

East South Central 3,100 290 500 3,900

West South Central 34,000 3,100 5,300 42,000

Mountain - - - -

Pacific 37,000 3,400 5,900 46,000

Puerto Rico 590 53 90 730

Nationwide 120,000 11,000 19,000 150,000

 

52 The previous section discusses that the energy penalties were initially assigned as zero percent for LNG and MGO 

options.
41

The numbers in Table 4-6 were converted to the fuel types tracked in NEMS: residual fuel oil, 

distillate fuel oil, and LNG. Based on global estimates of marine fuel use,53 the assumption was 

that low-sulfur IFO would be used in 2021 but that it would be composed of 10 parts IFO500 

(0% distillate), 60 parts IFO 380 (2% distillate), and 6 parts IFO 180 (12% distillate). The results 

for 2021 using the scenario where the LNG price is 30 percent below the HFO price appear in 

Table 4-7.

Table 4-7. Total Fuel Consumed (Billion Btu) in North American and U.S. Caribbean 

ECAs in 2021 by NEMS Fuel Type

Census Division Residual Fuel Oil Distillate Fuel Oil LNG Total

New England 2,100 400 200 2,700

Middle Atlantic 11,000 2,100 1,100 14,000

Midwest - - - -

West North Central - - - -

South Atlantic 32,000 6,000 3,000 41,000

East South Central 3,100 570 290 3,900

West South Central 33,000 6,200 3,100 42,000

Mountain - - - -

Pacific 36,000 6,800 3,400 46,000

Puerto Rico 570 110 50 730

Nationwide 120,000 22,000 11,000 150,000

 

53 IEA-AMF Organization. A Report from the IEA Advanced Motor Fuels Implementing Agreement- Alternative 

Fuels for Marine Applications. May 2013. Last accessed from http://www.ieaamf.org/app/webroot/files/file/Annex%20Reports/AMF_Annex_41.pdf on March 31, 2015.
42

5 Recommendations

The recommendations for EIA’s path forward include expanding the scope of the marine fuel 

estimates, fractionating the fuel purchases made in the U.S. versus abroad, and improving the 

future projections of fuel usage. An initial recommendation would be to consider a sensitivity 

analysis and determine the factors (e.g., slow steaming reductions and auxiliary power needs) 

that would most affect the fuel consumption estimates. A sensitivity analysis would help 

determine the factors for later investigations and also the best ways to relate the model to EIA’s 

model scenarios.

The expansion of the scope would likely center on improving EIA’s estimates of fuel usage in 

waters beyond the North American and U.S. Caribbean ECAs:

1. Remainder of ocean voyages beyond the ECAs

2. Great Lakes transit54

3. Inland waters transit

The expanded scope might also include fuel usage estimates for additional ships that may be 

more tied to U.S. ports for fuels:

1. Tugs, barges, and lightering vessels

2. Fishing vessels (most operate with C1 engines)

3. Cruise ships

4. Other commercial vessels

While the number of ships that operate full-time or nearly full-time in the North American ECA 

is small, they may exert a disproportionate influence on total energy consumption within the 

ECA due to the time that they spend in the ECA. Many of these will be U.S.-flagged vessels and 

include non-cargo vessels such as port tugboats and ferries. Their fuel consumption would be 

calculated with different assumptions about time spent within the ECA.

The U.S. commercial deep draft fleet and the U.S.-flagged oceangoing tug and barge operations 

to Alaska, Hawaii, Puerto Rico, and the Virgin Islands were considered very small and likely 

captured as port calls by the larger ships in the MARAD data. 

A future study might examine fuel purchasing to better understand what fraction of the fuel 

consumed within the ECAs was purchased at U.S. ports.

Many factors affect the total fuel consumption estimates (e.g., transit time, engine efficiency,

loads, and auxiliary power usage). The recommendations below address changes that could be 

made to baseline fuel consumption estimates (and those through 2014/2015):

1. Update the estimates to give consideration to active vessel speed reduction (VSR) 

programs which are currently required at a number of ports, which are mostly on the west 

 

54 These vessels and the inland fleet were excluded from this current model. The inland fleet (about 3,000 towboats) 

is using generally using domestically procured diesel oil for fuels, while the large Great Lake ships (about 76 North 

American ships full-time and 800 foreign port calls/year from Europe) are using IFO. The U.S. EPA has allowed 

some alterations to the ECA regulations in the Great Lakes. 
43

coast (including Ports of Long Beach, Los Angeles, and San Diego), and by the Port 

Authority of New York and New Jersey. VSR has also been evaluated at the Ports of 

Seattle and Tacoma, as well as the Port of Houston Authority. These speed reductions 

would be applied on a port-by-port basis and not scaled directly to the entire U.S. Census 

Division.

2. Update the estimates to give consideration to the expanding use of on-shore power (cold 

ironing). The Ships at Berth Regulation (California Air Resource Board) began requiring

use of on-shore power by OGVs by 50 percent of the fleet visits to California ports 

starting in 2014. Fleets affected by this regulation include container vessels, passenger 

vessels, and refrigerated cargo vessels.

3. Give future consideration in the model to congestion issues and delays at sea or at berth 

due to local infrastructure constraints or labor issues.

Other investigations might yield better estimates of the fuel types consumed in the baseline 

estimates. Worldwide numbers might be distributed to North America and the U.S. using the 

resources of BIMCO, IMO, and United Nations Conference on Trade and Development. An 

appropriate fraction of those numbers could be applied to the North American and U.S. 

Caribbean ECAs.55

Additionally some recommendations would apply to estimates in the future projections:

1. According to the baseline estimates in this study, 26 percent of the energy used for port 

calls was for auxiliary power. Auxiliary power requirements are the least documented on 

an international scale, but there is sufficient documentation available on a ship-by-ship 

basis to create typical auxiliary power needs by ship class. In addition, auxiliary power 

requirements can be greatly reduced by implementing new practices such as waste heat 

reclamation, cold ironing, solar panels, and switching to distillate fuels that do not require 

preheating.

2. Fully analyze the BIMCO report that chooses between using scrubbers versus burning 

MGO in ECAs.56 Perform a similar set of cost calculations for container ships because 

they represent almost half of the fuel consumption within ECAs in 2012.

3. Ship design speeds and engine sizes: A new study might predict potential cost savings or 

energy efficiencies based on multiple changes to ship design trends (e.g., ship speed, ship 

size, engine types, new technologies, adoption of best practices, and new environmental 

safeguards), their installation/operational costs, and confidence in the technologies 

involved (expressed as a probability of expected performance). This new study with an 

economics basis would allow for gaming potential changes and be based on the highest 

levels of expected return.

 

55 A 2008 report prepared for the U.S. EPA (Global Trade and Fuels Assessment—Future Trends and Effects of 

Requiring Clean Fuels in the Marine Sector, EPA420-R-08-021, November 2008) stated that Houston’s heavy fuel 

oil for marine activities was mostly imported from refineries in Venezuela, Mexico, and Aruba, so an understanding 

of U.S. imports for marine fuel might also be important.

56 BIMCO. “Business Case: Marine Gas Oil or Scrubbers When Operating in an ECA?” Published on 25 April 

2013. Last accessed from https://www.bimco.org/Reports/Market_Analysis/2013/0424_ECAStory.aspx on January 

22, 2015.
44

4. Add a Technology Adoption Model (TAM) to project the selection of strategies and 

associated fuel type for meeting marine environmental regulations. The primary TAM 

outputs would be marine demand for HFO, MDO, and LNG. The model would enable 

analyses of the effects of fuel prices, capital cost changes, and policy measures on the 

proportionate use of the different marine fuels. Model inputs and availability of these 

inputs are summarized in the Table 5-1. The TAM would also consider fuel incentives 

and low emissions shipping incentives.

Table 5-1. Model Inputs for a Possible Technology Adoption Model for Fuel Use 

Projections

Model Input Data Availability

Number of vessels by census region and 

ECA/non-ECA trade partner

Readily available at national level –

assumptions would likely be needed for 

regional level

Number of vessels by type and size class for 

tankers and container ships

Readily available at national level – regional 

level is available with additional effort

Number of vessels by age class Readily available at national level –

assumptions would likely be needed for 

regional level

Total marine energy demand by region An input from the output of the current 

project

Inland and coastal vessel energy demand 

by fuel type

An input variable as manual entry or from a 

separate coastal/inland technology adoption 

model

Fuel prices An input from NEMS

Average engine efficiency Available – some assumptions would be 

needed for applying to each vessel type and 

size class

Strategy capital costs Available – some assumptions would be 

needed for applying to each vessel type and 

size class

Strategy operating costs Available – some assumptions would be 

needed for applying to each vessel type and 

size class

Representative industry discount rate Available

 
45

Appendix A. Matrix-Based Derivations of Baseline Estimates

A.1 Notation

Class = Tanker, Container, Gas (LPG/LNG), Roll-on/Roll-off, Bulk, or General Cargo

CD = 9 U.S. Census Divisions and Puerto Rico

Year = 2012

A.2 Formulas

For the total nautical miles traveled:

TOTNMI2012,class,CD = ∑all ports in CD CALLS2012,class,port × ECADISTPERCALLport

where 

CALLS2012,class,port = number of calls to MARAD-tracked port in 2012 (by class and port)

ECADISTPERCALLport = distance traveled across ECA for port entry and exit (nautical miles)

For the average dead weight tonnage:

AVGDWT2012,class,CD = TOTALDWT2012,class,CD / CALLS2012,class,CD

where

CALLS2012,class,CD = number of calls to all MARAD-tracked ports in 2012 (by class and CD)

TOTALDWT2012,class,CD = total dead weight tonnage for all MARAD-tracked ports in 2012 (by 

class and CD)

For the total work associated with transit (ton-miles):

ECATRANSITWORK2012,class,CD = TOTNMI2012,class,CD × AVGDWT2012,class,CD

For the time transiting the ECA (hours):

TIMETRANSITINGECA2012,class,CD = TOTNMI2012,class,CD /[ENGDESSPDclass × 

SLOWSTMSPDREDclass,CD] 

where

ENGDESSPDclass = engine design speed (knots)

SLOWSTMSPDREDclass,CD = percentage of engine design speed achieved during slow steaming

For the engine sizes (kW):

ENGINESIZE2012,Class,CD is a function of AVGDWT2012,class,CD and read from MAN tables
46

For the energy spent during transit (kWh):

TRANSITENERGY2012,class,CD = ENGINESIZE2012,Class,CD × SLOWSTMPWRREDclass,CD × 

TIMETRANSITINGECA2012,class,CD

where

SLOWSTMPWRREDclass,CD = percentage of engine power reduction achieved during slow 

steaming

The transit fuel consumption is computed by multiplying the transit energy by the specific fuel 

oil consumption for transit (e.g., 0.175 kg/kWh for post-2001 slow-speed diesel engines):

TRANSITFUELCONS2012,class,CD = TRANSITENERGY2012,class,CD × SFOCtransit

where

SFOCtransit = specific fuel oil consumption for main propulsion engines

The auxiliary power usage of ships is generally reported as a percentage of the power used for 

transit under design conditions (e.g., 5%). The auxiliary power is assumed to continue operating 

while in port or at anchor within the ECA (e.g., 21 to 62 hours for loading/unloading in port).

Therefore, the auxiliary power spent while in the ECA can be calculated with the formula:

AUXENERGY2012,class,CD = [ENGINESIZE2012,class,CD × PCTAUX]

× [TIMETRANSITINGECA2012,class,CD + PORTTIMEclass× CALLS2012,class,CD]

where 

PCTAUX = percentage of the power used for transit under design conditions

PORTTIMEclass = average time spent in port or at anchor by a specific vessel class

The auxiliary fuel consumption is computed by multiplying the auxiliary energy by the specific 

fuel oil consumption for auxiliary engines (e.g., 0.225 kg/kWh):

AUXFUELCONS2012,class,CD = AUXENERGY2012,class,CD × SFOCaux

where

SFOCaux = specific fuel oil consumption for auxiliary engines

For the total fuel consumption while in the ECA (Btu):

FUELCONS2012,class,CD = TRANSITFUELCONS2012,class,CD + AUXFUELCONS2012,class,CD
47

Appendix B. Ship Routes to Avoid Significant Travel in North American 

ECA

Figure B-1. Ship routes (to San Diego- top and Brownsville- bottom) that would avoid 

most of the North American ECA by staying south of the ECA until jogging north to cross 

from Mexican into U.S. waters (shown as red lines)

Figure B-2. Approximate boundary (yellow) of North American ECA as a result of 

proximity to the Bahamas. White line shows a 20-nautical mile scale.
48

Appendix C. Adoption of Compliance Strategies by Ship Industry

C.1 Strategy Selection: Current Status

A typical economic evaluation for the selection of emissions compliance strategies includes 

standard economic measures of the capital and operating and maintenance (O&M) costs, savings 

associated with the use of cheaper fuels (i.e., HFO or LNG), and summary measures of payback 

and net present value (NPV). However, the confidence that can be placed in economic 

feasibility comparisons of marine compliance strategies at the present time is substantially 

limited by the immaturity of the technologies associated with two of the key strategies: exhaust 

scrubbers and LNG propulsion systems. While these strategies have been applied to land-based 

systems for decades, they have only been applied to relatively few ships within the last few 

years. The harsh marine environment (e.g., corrosive seawater), tight space limitations, and a 

high degree of design customization on marine vessels are significant factors to which 

manufacturers must adapt their products. Marine sulfur scrubbers and SCR systems and LNG 

propulsion systems can be described as being in the demonstration phase of development. 

Although multiple products are on the market for these strategies, it is estimated that there were 

fewer than 100 ships with LNG propulsion systems in 2013.57 With respect to scrubbers, 

according to the Exhaust Gas Cleaning Systems Association, as of November 2014, there are 

around 300 scrubber systems installed or on order, with greatest growth among ferries, cruise 

ships, and roll-on/roll-offs that spend a substantial portion of their time in ECAs.58 Experience 

with SCR on marine vessels is more substantial – it has been applied to marine vessels for about 

25 years, primarily as a retrofit. In 2013, there were 519 vessels operating with SCR 

worldwide.59 With a longer history of marine applications, and installation costs that are roughly 

one-tenth the costs for scrubbers, SCR represents a much lower financial risk than sulfur 

scrubbers or LNG, and is only needed for new builds beginning in 2016.

The tight profit margins associated with the highly competitive shipping industry mean the risks 

associated with adoption of a multi-million-dollar new technology can make or break a shipping 

company. With this understanding, a cautious adoption of scrubbers and LNG propulsion 

systems is expected, and most shippers will “test” one or both of these new technologies on a 

few of their vessels before making firm decisions regarding adoption for the remainder of their 

fleet. Further, since sulfur scrubbers and LNG substitution are strategies that comply with the 

0.1% fuel sulfur requirements for both existing and new-build vessels operating in ECAs, 

retrofits are viewed as a key near-term developing market for these strategies in addition to newbuilds. While some new builds on order incorporate sulfur scrubbers or LNG propulsion 

systems, others are being dubbed as “LNG conversion-ready” and “scrubber-ready,” thereby 

postponing the determination of an optimal compliance strategy.60

 

57 Shaw, Jim, May 1, 2013. “Propulsion: Is LNG the Future?” Pacific Maritime Magazine, 

http://www.pacmar.com/story/2013/05/01/features/propulsion-is-lng-the-future/152.html

58 The Maritime Executive, November 30, 2014. “Scrubber Sales Accelerate.” http://www.maritimeexecutive.com/article/Scrubber-Sales-Accelerate-2014-11-30

59 Alyson Azzara, Dan Rutherford, Haifeng Wang, March 2014. “Feasibility of IMO Annex VI Tier III 

implementation using Selective Catalytic Reduction,” ICCT Working Paper 2014-4, 

http://www.theicct.org/sites/default/files/publications/ICCT_MarineSCR_Mar2014.pdf

60 Ship & Bunker, September 17, 2014. “Construction Underway for "LNG-Conversion-Ready" Eco-Tankers,” 

http://shipandbunker.com/news/am/519431-construction-underway-for-lng-conversion-ready-eco-tankers
49

Common reasons for postponing selection of LNG and scrubber strategies include the lack of 

technology maturity for both of these strategies; uncertainty in regulations for LNG bunkering as 

well as for scrubber waste handling and disposal;61 the availability of trained crews (for both 

LNG and scrubbers); LNG fuel availability; and uncertainty in fuel price.62 While the general 

difference in HFO and MDO fuel prices is typically viewed as likely to continue, the magnitude 

of this difference is more uncertain, and there is yet more uncertainty in the relative price of 

LNG both over time and among global regions. The recent introduction of new financial 

instruments that shift fuel price risk from ship owners (or charterers) to financiers who pay for 

LNG or scrubber capital costs and collect the fuel savings as borrowers pay for the MDO that 

would have been burned63 may help to reduce the current avoidance of strategy selections that 

promise long-term savings. 

Many analysts are suggesting that the optimal compliance strategy will vary by individual ship 

depending on typical routes, proportion of time traveling in an ECA, frequency of use on other 

routes, engine design (i.e., ease of conversion to LNG), vessel design and balance,64 and vessel 

age. With respect to routes, the availability of fuel and maintenance services will influence 

strategy selections, and percent time in an ECA will substantially affect the magnitude of 

potential fuel savings and associated payback for both scrubbers and LNG.

While it will take years for adoption of strategies using currently immature technologies to 

become a significant portion of the OGV fleet, the technology options suggest the possibility that 

the marine transportation sector may ultimately demand three primary fuel types: distillate fuel, 

residual fuel, and LNG.

C.2 Projections of LNG and Scrubber Adoptions

Both scrubbers and LNG strategies are thought to be at the beginning of the traditional 

technology adoption “S-curve.” Several studies have projected that the adoption of scrubbers and 

LNG will initially be greatest among inland and coastal fleets that spend most of their time in 

ECAs or in regions with ECA-equivalent regulations (i.e., inland US waterways) where it would 

be easiest to build out the LNG bunkering. Regional liners with fixed routes are among the key 

targets for LNG. Some analysts suggest that scrubbers will be more prevalent in the regional 

European Union (EU) fleet than in the U.S., where LNG prices are expected to be more 

favorable.62,63 The more expensive closed-loop or hybrid scrubbers associated with low alkalinity 

(fresh) water supplies will also facilitate LNG competitiveness in inland waters. 

A number of groups have developed models for examining compliance strategy economics with 

regard to LNG market penetration, and some of these extend their analyses to project strategy 

 

61 Maritime Denmark, November 12, 2014. “Shipowners want information on scrubbers.” 

http://www.maritimedenmark.dk/?Id=18087

62 Semolinos, Pablo, et al., 2013. LNG as marine fuel: Challenges to be overcome. 17th International Conference and 

Exhibition on Liquefied Natural Gas (LNG17), Houston, TX, April 16-19, 2013. 

http://www.gastechnology.org/Training/Documents/LNG17-proceedings/7-2-Pablo_Semolinos.pdf

63 Ship & Bunker, June 26, 2014, "Industry Insight: Financing the Cost of ECA Compliance,"

http://shipandbunker.com/news/features/industry-insight/263088-industry-insight-financing-the-cost-of-ecacompliance

64 Some vessels may become unstable with the additional weight of a scrubber(s) at the top of the exhaust stack, 

others may not have enough space in the funnel casing for a scrubber system, and still others do not have the space 

to accommodate the larger footprint needed for LNG.
50

adoption over time. These collective results are summarized below for the next five years and 

then the subsequent ten years (2020 to 2030).

2015 to 2020 -- Inland ships and short sea ships (coastal shipping) with fixed routes are expected 

to be the first significant adopters of scrubber and LNG strategies due to the more rapid payback 

for vessels that operate almost entirely in regions with ECA-equivalent regulations.62,65,66 There 

will be a preference for LNG among vessels that are unable to install scrubbers due to design and 

stability issues (i.e., more common among ferries, roll-on/roll-offs, and product tankers).62 Other 

analysts have identified ferries and offshore supply vessels as prime candidates for the initial 

phase of LNG adoption in the U.S.67 

A study by DNV that considers global LNG bunker demand for new-build OGVs estimates that 

in 2020, LNG demand will be in the range of 8 to 33 million tons per annum (Mtpa), or 400 to 

1,700 TBtu/yr. Corresponding HFO demand is estimated to be 80 to 110 million tons (13,000 to 

20,000 ships with scrubbers) assuming the global sulfur rule begins in 2020. Other analyses that 

consider a wider range of vessel types suggest more favorable economics for LNG among small 

and mid-size ships versus large and very large ships.62,65 The expected proportion of new-builds 

versus retrofits is expected to vary among vessel types and will likely be determined by both fuel 

price spreads and early reports of experiences with both scrubbers and LNG. A study by Angola 

LNG and Total that considers vessel types and adoption behaviors estimates that by 2020, 

bunker LNG demand will be in the range of 3 to 5 Mtpa (150 to 250 TBtu/yr) in North America 

and 5 to 8 Mtpa in Europe.62 While these total LNG demand estimates are similar to DNV’s 

2020 low-end LNG demand estimates, the critical distinction is where the demand is located. In 

the view of the Angola LNG and Total paper, smaller ports will gradually develop sufficient 

LNG demand to invest in larger LNG bunkering operations that will facilitate LNG adoption 

among deep-sea liners in the next decade.

2020 to 2030 -- After LNG becomes available in several ports in a region (i.e., North America, 

Europe and Asia), some short sea ships without fixed routes may begin to convert as well as 

some deep sea liners (intercontinental shipping). The latter, in particular, are expected to be 

primarily new or recently built vessels designed to be “conversion-ready.” Major container-ship 

operators will begin ordering a few LNG ships to test this strategy, and if the tests prove positive,

will likely diversify their fuel and technological risks by switching part of their fleet to LNG.

62

However, the need for route flexibility limits the use of LNG among deep sea very large crude 

carriers (VLCCs) and bulk carriers, suggesting a higher rate of scrubber use among these 

categories.

A study by Marine and Energy Consulting has projected that globally about 6,000 marine 

scrubber systems will operate on ships by 2025, consuming 28 million metric tons of HFO per 

year (a slower adoption rate than the low end of 80 million tons estimated by DNV for 2020). 

The Marine and Energy Consulting study also suggests that in 2025, about 1,700 smaller vessels 

 

65 Andersen, Mads Lyder et al., 2011. "Costs and benefits of LNG as ship fuel for container vessels: Key results 

from a GL and MAN joint study." http://www.gl-group.com/pdf/GL_MAN_LNG_study_web.pdf

66 Zeus Intelligence, May 27, 2014. “LNG Ready: The Key to Deep-Sea LNG Fuel?” 

http://member.zeusintel.com/ZLFMR/news_details.aspx?

67 Zeus Intelligence, July 23, 2013. “Economic Analysis of LNG Vessel Costs in North America,” 

http://member.zeusintel.com/ZLFMR/news_details.aspx?newsid=30096
51

will consume 8 Mtpa (400 TBtu/yr) of LNG, representing about 11% of total bunkers.68 In 

contrast, the study by Angola LNG and Total estimates that by 2030, global bunker LNG 

demand will be considerably higher, in the range of 20 to 30 Mtpa (1 to 1.5 QBtu/yr).

62

C.3 Compliance Strategy Cost Estimation

The three Tier III compliance strategies could employ a total of four technologies: LNG 

propulsion systems, exhaust scrubbers, MDO adaptations, and SCR (the latter of which is used in 

conjunction with the previous two technologies). The additional uncertainties that surround the 

use of immature technologies for scrubbers and LNG compliance strategies limit the confidence 

in cost estimates for these strategies. Technology improvements in production and installation of 

engines and fuel systems are expected to largely decrease the installation costs for LNG and 

scrubbers, reducing the payback period for projects. The costs provided in this section do not 

attempt to adjust for anticipated cost-reductions as these technologies mature. Costs associated 

with each of the four technologies are briefly discussed below followed by a summary table of 

“typical” costs for the technology (Table C- 1).

MDO Adaptation -- Most OGV are designed to operate on HFO, but can burn MDO with the 

addition of a fuel cooler or chiller and associated piping prior to the fuel pump to decrease fuel 

viscosity.69 This retrofit typically requires about fourteen days in the shipyard.70 The cost of 

modification for a medium range tanker (38,500 dwt, 9,4800 kW MCR) to use MDO has been 

estimated to be around $800,000, including the fuel cooler, piping, shipyard services, etc.70 This 

cost will vary with vessel size and design, and the ability to include this conversion during 

regularly scheduled shipyard visits. MDO is already available in ports and there are no problems 

regarding regulations, logistics or operations. However, if demand for MDO rises significantly, 

infrastructure expansions would be needed, and refining balances in some regions may be 

disrupted with resulting price impacts until new equilibriums are established.71 This increases the 

fuel price risk for operating with MDO. 

SCR -- The costs of SCR are driven by capital costs, which vary with engine design. In general, 

the larger the engine, the less expensive the installation costs per kW. SCR operating expenses 

are dominated by the cost of the reducing agent (urea). Additional operational costs are incurred 

for catalyst replacement (typically every five or six years) and for the additional fuel 

consumption associated with SCR use.72

 

68 Ship & Bunker, April 7, 2014. “$15 billion in Scrubber Sales Predicted by 2025,” 

http://shipandbunker.com/news/world/707962-15-billion-in-scrubber-sales-predicted-by-2025

69 The International Council on Combustion Engines (CIMAC), 2013. “Guideline for the operation of marine 

engines on low sulfur diesel,” 

http://www.cimac.com/cms/upload/workinggroups/WG7/CIMAC_SG1_Guideline_Low_Sulphur_Diesel.pdf 

70 Kotakis, Nikolaos K. 2012, “Cost Comparative Assessment Study between Different Retrofit Technologies 

applied on Model Ship to Conform to IMO MARPOL 73/78, Annex VI, Reg. 14,” Masters Thesis, University of 

Greenwich. 

https://www.academia.edu/8507275/Cost_Comparative_Assessment_Study_between_Different_Retrofit_Technolog

ies_applied_on_Model_Ship_to_Conform_to_IMO_MARPOL_73_78_Annex_VI_Reg._14

71 It should be noted that refining balance issues are more commonly cited as a concern for Europe than for North 

America.

72 IACCSEA, 2012. “White Paper: The Technological and Economic Viability of Selective Catalytic Reduction for 

Ships”, http://www.iaccsea.com/fileadmin/user_upload/pdf/iaccsea_white_paper.pdf .
52

In a study of the North Sea fleet adoption of NOx strategies, technologies considered include 

SCR, EGR, and LNG.36 The analysis did not require application of the same technology to both 

the main and auxiliary engines. It was found that for 2-stroke engines, annual total (i.e., 

levelized) costs of EGR were only 68% of the SCR costs (on average), while SCR costs for 4-

stroke engines were 83% of EGR costs.73 Levelized costs of the most cost-efficient NOx strategy 

were found to vary greatly by both ship size and type. In the North Sea Fleet analysis, the fleet’s 

total compliance costs were estimated for comparison to total benefit costs, and compliance 

capital costs were linked to the number of new ships projected to be built from 2016 to 2030, 

with consideration of efficiency changes and slow steaming. Throughout the analysis timeframe, 

fuel and capital costs represented 12-14% and 58-59% of the total costs, and the non-fuel 

operating costs ranged from 27-30%. This distribution suggests that fuel price changes over time 

are a relatively minor cost component for NOx compliance.

With respect to capital costs for SCR installation on 2-stroke, slow speed engines, the following 

linear relationship to engine size has been found (using Euros): €/kW = -0.71a + 59.5 where “a” 

is the engine size (kW).36 This relationship suggests a relative reduction in SCR cost with engine 

size.

Sulfur Scrubbers -- The capital costs of scrubber installation vary significantly with vessel 

design. Scrubbers may treat one or more engines. Scrubber retrofit costs are increased when 

there is a need for major modification of the ship’s exhaust funnel to accommodate the scrubber 

system. Advances in both scrubber size reduction and multi-streaming configurations that enable 

the use of one scrubber unit for multiple engines74 and varying loads are promising developments 

for capital cost reductions. Furthermore, new scrubber designs that are lighter and lower the 

system’s center of gravity enable compatibility of scrubber systems on a wider range of existing 

vessels.

The retrofit of a typical vessel with a 10-MW engine includes around 25 days in the shipyard, 

with roughly half of the installation costs associated with the scrubber system equipment, and the 

remainder for the shipyard account, certifications, inspections, etc.70,75 Initial scrubber purchases 

were dominated by open-loop designs, but hybrid scrubbers are becoming more common to 

provide the greatest flexibility in routes by enabling travel in ECA coastal and inland waters with 

low alkalinity. Recognizing this trend, the cost summary table below (Table C- 1) assumes a 

hybrid scrubber, which typically costs around 20% more than an open loop scrubber.76 

In addition to capital costs, the use of scrubbers has incrementally higher operating costs due to 

the added logistics and maintenance for water treatment products and sludge management, and 

 

73 In general, 2-stroke engines are more common for the main engines of larger vessels, while 4-stroke engines are 

more common for auxiliary engines and smaller vessel main engines.

74 Exhaust Gas Cleaning Systems Association (EGCSA), November 18, 2014. “CR Ocean Industries Scrubber –

Lighter, Smaller, More Efficient,” http://www.egcsa.com/another-egcsa-member-cr-ocean-engineering-llc/

75 Nielsen, Christian Klimt and Christian Schack, 2012. "Vessel Emission Study: Comparison of Various Abatement 

Technologies to Meet Emission Levels for ECA's", 9th annual Green Ship Technology Conference, Copenhagen 

2012. http://www.greenship.org/fpublic/greenship/dokumenter/Downloads%20-

%20maga/ECA%20study/GSF%20ECA%20paper.pdf

76 Aminoff, Tomas, 2014. “A glance at CapEx and OpEx for compliance with forthcoming environmental 

regulations,” 16th Annual Marine Money Greek Forum, October 15, 2014, 

http://www.marinemoney.com/sites/all/themes/marinemoney/forums/GR14/presentations/1220%20Tomas%20Amin

off.pdf
53

fuel consumption increases of 1 to 3%. Over the years, new-generation scrubbers with more 

efficient operation resulting in less frequent catalyst replacement and a lower fuel penalty may 

gradually reduce these costs.77 As scrubber technology for marine applications matures, both the 

capital and operating costs of this compliance strategy are expected to decrease in terms of real 

dollars. 

Achieving a reduction of sulfur by using a wet scrubber means increasing power usage 

significantly to pump water.

LNG -- The capital costs of new-build LNG vessels are currently estimated to be about 20% 

more than conventional vessels.76 Approximately one sixth of the incremental capital costs for 

LNG relate to the vessel engines, while the remainder is for the LNG storage tanks, safety 

systems, and other ship modifications.78 Vessel retrofits to use LNG typically take around 45 

days, but this will likely be reduced for the new “conversion-ready” vessels. The immaturity of 

LNG technology for marine applications substantially limits the confidence in current engine and 

storage costs to be representative of capital costs several years in the future. For example, one 

engine manufacturer has claimed that their recently introduced LNG engine provides a 15 to 

20% reduction in capital costs as a result of design improvements.27 

The lower energy density of LNG compared to MDO and HFO means the fuel tank has a larger 

footprint. As such, conversion of existing vessels to LNG requires a higher threshold of fuel 

savings to compensate for greater cargo losses with LNG, which are of greatest concern for 

container ships and bulk carriers. The medium-sized container vessels (4,600 TEU to 8,500 

TEU) are estimated to have the largest proportionate cargo losses, equivalent to as much as 3% 

of cargo capacity.65 Cargo losses are reduced for new-builds that are designed for LNG use, and 

the ongoing development of membrane fuel tanks that conform to the ship’s hull can further 

reduce cargo losses.62 For retrofits, some types of tankers and roll-on/roll-offs are thought to be 

able to relatively easily install type C LNG storage tanks on the deck with no or minimal cargo 

losses.

62

 

Maintenance costs for the LNG propulsion system are general estimated to be around 15% lower 

than those costs for conventional vessels,76 but experience with these vessels has not been 

extensive enough to provide substantial field confirmation of the magnitude of this expected 

benefit. Other non-fuel operation costs such as crew and spare parts have been estimated to be 

10% higher than for MDO.65 Additional costs associated with the learning curve for use of a 

cryogenic fuel are also not well established.

LNG bunker costs include the regional LNG fuel price and port logistics costs. For ports with 

small LNG bunkering operations, these costs are estimated to be in the range of $2 to 

$3.5/MMBtu. Unit costs can be lower for larger ports but initial investment is higher, and the 

risk of overinvestment is viewed as particularly high when the market supplied is less than 0.25 

Mtpa. An incremental growth in port capabilities for LNG bunkering is viewed as a means to 

control these risks, with initial bunker operations supplied by trucks. Investment in port 

infrastructure for LNG buffer storage, LNG bunker vessels, and port-side liquefaction becomes 

more appealing as LNG bunker demand approaches and exceeds 1 Mtpa.62

 

77 Exhaust Gas Cleaning Systems Association (EGCSA), November 18, 2014. “CR Ocean Industries Scrubber –

Lighter, Smaller, More Efficient,” http://www.egcsa.com/another-egcsa-member-cr-ocean-engineering-llc/

78 American Clean Skies Foundations (ACSF), 2012, Natural Gas for Marine Vessels, US Market Opportunities,” 

http://www.arcticgas.gov/sites/default/files/documents/2012-clean-skies-lng-marine-fuel.pdf .
54

The table below provides typical costs for each of the discussed compliance strategies for an 

average vessel with a 10-MW main engine. The point costs shown in this table are an average of 

the referenced sources, which are for engines within 20% of the target size (i.e., 10 MW).

Table C- 1. Typical Preliminary Cost Estimates for an “Average” Ship with a 10,000 kW 

Engine

Control Option

Capital Costs

Incremental Operating Costs 

(non-fuel, 100% time in ECA)

$ millions Source $ millions/ year Source

MDO (i.e., fuel chiller 

and piping)

0.8 a minimal

Scrubber (hybrid) 6.5 a, b, c, 

e

0.1 (sludge handling)

0.1 (catalyst, levelized cost)

0.2 (caustic soda)

c, e

LNG 9.3 a, b, c 15% maintenance reduction e

SCR 0.5 d 0.2 (urea) c, d

a. Kotakis, Nikolaos K., 2012. “Cost Comparative Assessment Study between Different Retrofit Technologies 

applied on Model Ship to Conform to IMO MARPOL 73/78, Annex VI, Reg. 14,” Masters Thesis, University 

of Greenwich. 

https://www.academia.edu/8507275/Cost_Comparative_Assessment_Study_between_Different_Retrofit_Tech

nologies_applied_on_Model_Ship_to_Conform_to_IMO_MARPOL_73_78_Annex_VI_Reg._14

b. Nielsen, Christian Klimt and Christian Schack, 2012. "Vessel Emission Study: Comparison of Various 

Abatement Technologies to Meet Emission Levels for ECA's", 9th Annual Green Ship Technology Conference, 

Copenhagen 2012. http://www.greenship.org/fpublic/greenship/dokumenter/Downloads%20-

%20maga/ECA%20study/GSF%20ECA%20paper.pdf

c. Hagedorn, Matthias, 2014. "LNG Engines, Specifications, and Economics", Rostock LNG Value Chain 

Seminar, Klaipeda 2014. 

http://www.golng.eu/files/Main/20141017/Rostock/LNG%20Shipping%20Session%20II%20-

%20LNG%20Engines-Specifications%20and%20Economics-

%20W%C3%A4rtsil%C3%A4,Ship%20Power%20-%20Hagedorn.pdf

d. International Association for Catalytic Control of Ship Emissions to Air (IACCSEA), Marine SCR – Cost 

Benefit Analysis. http://www.iaccsea.com/fileadmin/user_upload/pdf/SCR_cost_calculation_model2_v1.pdf

e. Aminoff, Tomas, 2014. “A glance at CapEx and OpEx for compliance with forthcoming environmental 

regulations,” 16th Annual Marine Money Greek Forum, October 15, 2014, 

http://www.marinemoney.com/sites/all/themes/marinemoney/forums/GR14/presentations/1220%20Tomas%20

Aminoff.pdf 
55

Appendix D. Computation of Port Times

During the time a ship is at anchor or is at berth the main propulsion engine is usually shut down, 

but the auxiliary power units continue to operate. Initially the combined time at anchorage and in 

port was assumed to be 72 hours. The time the ship spends in port is usually dependent on the 

time it takes to load/unload the ship and contingent on the volumes involved and the efficiency 

of the loading/unloading operations. Both times at anchor and times in port are impacted by peak 

loading periods. While port data are not available from all ports regarding these times, there are 

sufficient data available to better approximate these times by terminal types (i.e., large west coast 

container terminals, large east coast container terminals petroleum terminals, and coal loading 

terminals).

Ships are sometimes diverted to ship anchorages in or near the port prior to going to the terminal 

where they will load or unload cargo. The primary reason for going to an anchorage is that the 

ship berth at the destination terminal is not available (another ship is there). Other reasons 

include the need to wait until high tide if channel depth is not adequate, or the U.S. Coast Guard 

requires a ship inspection prior to the ship entering port. The first two reasons for a ship going to 

anchorage are schedule-related and are avoided or minimized, in most cases, by proper planning. 

Inspections by the Coast Guard do not normally require the ship to go to anchorage ‘unless there 

is a compelling reason (high interest vessel, specific intelligence, or other intelligence that 

renders the risk of a vessel entering port to be high without a Coast Guard exam for safety and/or 

security); the exams will be conducted either in port or sometimes while en route to the 

facility.’

79 Because of the infrequency associated with anchorage, anchorage times are not 

reflected in the calculations.

D.1 Container Ships

Port times for container ships were based on berth productivity rates (container handling speed) 

and volume of containers moved/handled.80 A Journal of Commence sponsored study81

determined that berth productivity was generally based on the average ship size (capacity) being 

worked. MARAD data5 was used to calculate the average ship size (in TEUs) for each of the 32 

ports that were used to estimate the port times for the model. Six ports also had berth 

productivities listed in the white paper. By assuming two eight-hour shifts for loading/unloading, 

the berth productivity per day was computed by multiplying by sixteen hours per day. The time 

in port was computed by dividing the number of TEU handled per call by the berth productivity 

(TEU per day).

The number of containers moved when a ship calls on a port includes containers being offloaded, 

loaded, or repositioned on the ship. In theory, a port can unload and load 200 percent of a 

 

79 Email from USCG headquarters on February 24, 2015; Michael.L.Blair@uscg.mil

80 Berth arrival and departure refer to “lines down” and “lines up” — that is, the actual arrival and departure of the 

ship at berth. The calculation of moves per hour between these two times is referred to as unadjusted gross berth 

productivity.

81 JOC Group Inc. “Berth Productivity: The Trends, Outlook and Market Forces Impacting Ship Turnaround 

Times,” July 2014. Accessed from http://www.joc.com/whitepaper/berth-productivity-trends-outlook-and-marketforces-impacting-ship-turnaround-times-0. 
56

vessel’s capacity (100% off, 100% on) in one port call.82 An American Association of Port 

Authorities (AAPA) Advisory83 was used to determine the total number of TEUs handled at the 

individual container ship ports. The number of containers handled in each port divided by the 

daily berth rate and number of container ship port calls yielded the average port time in days for 

container ships.

Data on container handling at six ports (Anchorage, Honolulu, Palm Beach, San Diego, San 

Juan, and Wilmington Delaware) produced outcomes that did not align with normal practices, so 

the schedules for those ports were examined in greater detail in order to compute the true times 

spent in port. Explanations for their deviations from standard container ship operations revealed 

that those average ships had not spent an inordinate number of days in ports, and the port times 

were adjusted based on reported values rather than on berth productivity.

The call-weighted average port times for the 32 ports were computed to be 1.8 days for container 

ships.

Note that fuel usage during port times has decreased significantly in California in recent years 

based on regulation requiring shore power84 at the Ports of Hueneme, Los Angeles, Long Beach, 

Oakland, San Diego, and San Francisco.85 This regulation affects the corporate fleets as follows:

 From 2014 through 2016, at least fifty (50) percent of the fleet’s visits to the port shall 

connect to shore power.

 From 2017 through 2019, at least seventy (70) percent of the fleet’s visits to the port shall 

connect to shore power.

State regulations were not the subject of this investigation, but adjustments could be made to the 

calculations to account for such measures in the years beyond the baseline. Connecting to shore 

power, also referred to as ‘cold ironing’, is a fairly rare occurrence outside of container and 

cruise ship terminals in California. A few cruise ship terminals in Washington, Alaska, New 

York, and elsewhere have shore power, but there was no indication that cargo ships are using 

shore connection outside of California, with the exception of one cargo ship operator in 

Tacoma.

86

D.2 Tanker Ships and Tank Barges

Port times were generally based on the "Allowed Laytimes" published by Exxon, Phillips 66, 

Shell, and APEX oil.87 Allowed Laytimes are the lengths of time vessels may occupy berths at a 

 

82 Diagnosing the Marine Transportation System – June 27, 2012 Research sponsored by USACE Institute for Water 

Resources & Cargo Handling Cooperative Program www.tiogagroup.com/215-557-2142

83 “NAFTA Region Port Container Traffic 2012.” May 6, 2013. Published at http://aapa.files.cmsplus.com/Statistics/NAFTA%20REGION%20PORT%20CONTAINER%20TRAFFIC%20PROFILE%202012.pdf

84 Section 93118.3 of Title 17, Chapter 1, Subchapter 7.5 of the California Code of Regulations. Airborne Toxic 

Control Measure for Auxiliary Diesel Engines Operated on Ocean-Going Vessels At-Berth in a California Port.

Last accessed from http://www.arb.ca.gov/ports/shorepower/finalregulation.pdf, on February 27, 2015. 

85 The Ports of Hueneme, Los Angeles, Long Beach, San Diego, and San Francisco represented 73 percent of the 

2012 dead weight tonnage of container ships in the Pacific Census Division (based on MARAD data).

86 TOTEM Ocean Trailer Express uses shore power for two of its ships when they are in Tacoma; 

http://www.portseattle.org/Environmental/Air/Seaport-AirQuality/Documents/nw_ports_clean_air_implementation_2013.pdf

87 Information collected from multiple online documents: http://www.apexoil.com/mp.pdf, 

http://www.exxonmobil.com/files/corporate/bsa_marineprovisions_and_specialprovisions.pdf,
57

terminal in order to conduct transfer operations without incurring additional charges. Allowed 

Laytimes are essentially contract terms, often listed as ‘Provisions for U.S. Delivery and 

Loading.’ The contractual terms are fairly consistent across different companies. Tank barges are 

allotted 12-36 hours depending on size (24 hours was used for tank barge port time). If the 

average tank vessel calling on a port was 27,000 DWT (about 180,000 barrels) or less, the 

vessels were assumed to be barges. 

All ports with larger average vessels were assumed to be tanker ships. Tanker ships are normally 

allotted 36 hours at berth. Exceptions to the standard port times were used for: 

 Valdez Alaska (crude oil loading port) where 12 hours port times are documented, 88 and

 Louisiana Offshore Oil Port where published discharge rate requirements indicated 48 

hours were necessary.

89

 Offshore lightering areas: South Sabine Point and Galveston Lightering Areas (near 

Texas coast), the Southwest Pass Lightering Area (near Louisiana coast), and the 

Southern California Lightering Area (near California coast). Offshore lightering 

normally takes place 20 or more miles and involves transferring oil from Very Large or 

Ultra Large Crude Carrier (VLCC or ULCC) tank ships that are too large to come into 

port to four to six smaller tank ships (80,000 DWT). Oil is transferred one ship at a time 

while both ships move at 4 to 6 knots.

90

 The VLCC or ULCC never actually enter the 

port. The smaller tank ships and the crude oil from the VLCC or ULCC do enter port and 

are recorded as ship arrivals. The VLCC or ULCC were excluded from the calculation of 

port times, but their activity levels within the ECAs may be a subject for future 

characterization.

The call-weighted average port times for 70 ports with tankers and tank barges were computed to 

be 35.9 hours, or 1.5 days.

D.3 General Cargo

General Cargo ships transport many types of cargos ranging from sacks, to drums, to oversized 

fabricated structures, as well as trees, and steel products such as rebar. The three ports with the 

most General Cargo ship port calls are: Houston, Philadelphia, and New Orleans. These ports 

represent about 30% of the General Cargo Ship U.S. port call in 2012. The Port of Houston 

states on their website that “the average turnaround time for a ship at the terminal (General 

Cargo) is two to three days.” Philadelphia does not list average turnaround times on their 

website, but a review of vessel AIS data91 for ships that departed between February 27 and 

March 2, 2015 indicated the average turnaround time was 65 hours. The port operations 

 

http://www.phillips66.com/EN/products/Documents/Phillips%2066%20Crude%20Oil%20Marine%20Provisions.pd

f, and http://www.shell.com/content/dam/shell-new/local/corporate/corporate/downloads/doc/shell-tradingcompany-domestic-marine-crude-oil-may-2013.pdf

88 Marine Exchange of Alaska. “Valdez Harbor Information.” From 

http://www.mxak.org/ports/southcentral/valdez/valdez_facilities.html, the transfer rates from fixed platform were 

100,000 bbl/hr and from floating units were 80,000 bbl/hr.

89 Loop LLC. “Tanker Offloading Services.” From https://www.loopllc.com/Services/Tanker-Offloading, the tank

ships of 170,000 DWT or greater must have a minimum average discharge rate of 43,000 bbl/hr.

90 Center for Tankship Excellence. “CTX Glossary.” From http://www.c4tx.org/ctx/gen/glossary.html

91 MarineTraffic. “Live Map.” http://www.marinetraffic.com/
58

manager at the Port of New Orleans stated in an email92 that “Within the Port of New Orleans 

jurisdiction, most general cargo ships are container and break-bulk vessels. Container ship 

average 1-1.5 days, while break bulk ships average 2-3 days.” Based on the ranges stated above,

an average port time for General Cargo ships of 62 hours (2.6 days) was used.

D.4 Roll-On/Roll-Off Vessels

The configuration of roll-on/roll-off ships varies significantly. Some roll-on/roll-off ships are 

designed specifically to only transport automobiles, others are designed to transport truck trailers 

and intermodal containers on truck chassis, and some are designed to transport truck trailers, 

containers and break bulk cargo. A review of vessel tracking data93 was conducted for the ports 

of Baltimore, Jacksonville, New York, Brunswick Georgia, Tacoma, Norfolk (Hampton Roads), 

and Portland (Columbia River). These ports accounted for 3276 of the 6247 roll-on/roll-off 

vessel port calls in 2012. An average port time for roll-on/roll-off vessels of 21 hours was 

observed. In general it appeared that roll-on/roll-off vessels moving only vehicles (cars, trucks, 

and trailers) were in port 12 to 16 hours and mixed use roll-on/roll-off vessels were in port 24 to 

30 hours.

D.5 Gas Vessels

Gas vessels include both LPG and LNG ships. The allowed laytime for an LNG ship at the 

Sabine Pass Terminal is 36 hours.94 At the Lake Charles LNG terminal the allowed laytime is 24 

hours.95 The ‘Report to Cook Inlet Risk Assessment Advisory Panel, version: January 2012” 

reports that LNG ships calling on the ConocoPhilips LNG loading terminal in Alaska during 

2010 spent 36 days in the Cook Inlet to conduct 12 port calls (average 3 days in the Cook Inlet). 

Since the terminal is 115 nm up the Inlet (230 nm round trip) it would take the ship about 29 

hours to transit in and out of the Inlet (leaving an average of 42 hours berth time for each ship at 

the terminal). Based on these data, LNG ships were assumed to be in port 36 hours for each port 

call.

At this time LNG ships generally load at a single port and unload at another single port. On the 

other hand, LPG ships may carry products destined for multiple ports, but ascertaining which 

ships would be resource-intensive. Because little data were available for LPG ship laytimes, the 

port times for LPG vessels were conservatively chosen to match those for the LNG ships 

conducting full loading/unloading (36 hours or 1.5 days).

 

92 Email from: Paul Zimmermann [ZIMMERMANNP@portno.com] 3/2/2015 to O’Malley, Steve J. (Leidos) on 

Monday, March 2, 2015 1:58 PM

93 For the period 2/26/2015 – 3/1/2015, this period included 43 port calls, 

http://www.marinetraffic.com/ais/details/ports/1326/USA_port:BRUNSWICK

94 U.S. Securities and Exchange Commission. “Master Ex-Ship LNG Sales Agreement Between Cheniere 

Marketing, Inc. and Gaz de France International Trading S.A.S.” 

http://www.sec.gov/Archives/edgar/data/3570/000119312507106384/dex102.htm

95 Decker, John. Letter to Sally Kornfeld, U.S. Department of Energy. Last accessed online at 

http://www.fossil.energy.gov/programs/gasregulation/authorizations/2004_Applications/04-40-LNG.pdf on March 

5, 2015.
59

D.6 Bulk Vessels

The average DWT and ship capacity (in tons) was calculated for 65 ports using the U.S. 

Maritime Administration’s 2012 Total Vessel Calls in U.S. Ports, Terminals and Lightering 

Areas Report.5 The average DWT was multiplied by 0.85 in order to estimate cargo capacity of 

the ships.96 The rate at which bulk cargo would be loaded or unloaded is based on ton-per-hour 

(tph) rates posted by the ports97 (assumed to be 800 tph if no information was posted). All 

posted rates are multiplied by 80 percent for probable efficiency unless the posted rates are 

actual averages. In addition, preparation times of four hours were added to the computations.

98

The call-weighted average port times for 65 ports with bulk cargo vessels were computed to be 

47.9 hours, or 2.0 days.

 

96 Agerschou, Hans. Planning and Design of Ports and Marine Terminals, 2nd Edition, 2004, Thomas Telford 

Publisher

97 The web site www.worldportsource.com provided the data or provided a link to the specific port website 

98 The preparation times were already included in the calculations for the other types of vessels when reporting 

laytimes and berth productivity.