Oil Spill Risks From Tank Vessel Lightering (1998)

The safety record of lightering (the transfer of petroleum cargo at sea from a large tanker to smaller ones) has been excellent in U.S. waters in recent years, as evidenced by the very low rate of spillage of oil both in absolute terms and compared with all other tanker-related accidental spills. The lightering safety record is likely to be maintained or even improved in the future as overall quality improvements in the shipping industry are implemented. Risks can be reduced even further through measures that enhance sound lightering standards and practices, support cooperative industry efforts to maintain safety, and increase the availability of essential information to shipping companies and mariners. Only continued vigilance and attention to safety initiatives can avert serious accidents involving tankers carrying large volumes of oil.

Lightering is an effective and cost-efficient method of delivering foreign crude oil to U.S. refineries and importing petroleum products. Lightering is necessary because very large tankers, which are often used to move cargo from the Arabian Gulf and other distant sources of oil, are too wide and too deep to enter most U.S. ports. Transferring part or all of the cargo to smaller vessels for delivery to terminals is less expensive than moving all of the cargo the entire distance in a larger number of smaller vessels.

Lightering safety became a topic of national interest several years ago because of public concerns about oil spills in general. The Coast Guard Authorization Act of 1996 requires that the U.S. Coast Guard (USCG) coordinate with the Marine Board of the National Research Council (NRC) to conduct studies on the risks of oil spills from lightering off the U.S. coasts. Accordingly, an 11-member

committee was assembled by the NRC, under the auspices of the Marine Board, to evaluate current lightering practices and trends, analyze the safety record, assess the regulatory and standards-setting framework, analyze accident prevention and risk reduction measures, and recommend technical and institutional improvements. The highlights of the one-year study and the committee's 16 recommendations are summarized below.

More than 25 percent of the 7.5 million barrels of crude oil imported into the United States each day is lightered. Small amounts of refined products are also lightered.¹ Approximately 95 percent of offshore lightering (i.e., outside the territorial sea, which generally extends three miles off the U.S. coastline), by volume, takes place in the Gulf of Mexico, according to government data. Additional offshore lightering takes place off Long Island, near the New Jersey and Virginia capes, off San Diego in California, and near the Bahamas. More than two-thirds of inshore lightering (i.e., within the territorial sea), by volume, takes place on the East Coast, primarily in the Delaware Bay and River and Long Island Sound. The rest of the inshore lightering takes place on the West Coast, in San Francisco Bay. The committee's estimates of the volume of oil involved in inshore lightering, combined with government data on offshore lightering, provide the most complete picture of U.S. lightering activity available to date. Although the projected increase of U.S. oil imports may lead to an increase in lightering, the committee expects that increases in the near term will be small and that current lightering patterns and volumes will remain fairly steady.

In the following sections, the vessel from which the cargo is removed is referred to as the ship to be lightered (STBL), and the receiving vessel is referred to as the service vessel. The STBLs and service vessels may either be owned by an oil company or chartered on a long-term basis or for a specific voyage. The STBLs are typically large tankers. A number of U.S. companies are engaged solely in the lightering business and operate service vessels. Service vessels may be all-purpose tankers, tankers equipped specifically for lightering, integrated tug-barge units equipped specifically for lightering, or standard all-purpose tug-barge units.

Even though an immense amount of information is available on maritime accidents in general, it is difficult to collect reliable data on the history of oil spills related to lightering in U.S. waters. The deficiencies in the data include inconsistent reporting and ambiguous information on the underlying causes of accidents. For this study, the accident data, which varied greatly in detail and reliability, were collected from various sources, including the USCG, state agencies, shipping companies and organizations, and other private sources. The

committee attempted to identify and assess only those spills that were attributable directly to mishaps during lightering operations.

The combined data showed an excellent safety record, which was verified by substantial anecdotal evidence and numerous interviews, as well as the personal experience of committee members. The USCG data for 1984-1996 indicate that few spills occurred during lightering on U.S. coasts, and the average spill volume was only 26 barrels (1,095 gallons). Recurring causes of spills that appear to be directly related to lightering include valve failures, tank overflows, and hose ruptures. The committee collected additional data from the USCG, industry, and state agencies for 1993–1997. During that time, no spills were reported on the east or west coasts, and only seven spills (accounting for less than 0.003 percent of the total volume lightered) were reported in the Gulf of Mexico. Only one spill was substantial, resulting from a collision in 1995 near Galveston, Texas; in that case, more than 850 barrels (35,700 gallons) of fuel oil were spilled. The cause of the accident was attributed to both limited communications and procedural errors, according to the USCG.

Various controls have been imposed on lightering (and tanker operators in general) by international agreements and U.S. laws and regulations. The USCG oversees lightering operations outside port areas through six general mechanisms: vessel design requirements, operational procedures, personnel qualifications, oil spill contingency planning and equipment requirements, vessel inspection, and monitoring. Three separate sets of regulations have been promulgated by the USCG regarding lightering activities. One set applies to lightering in inshore waters. For this purpose, inshore waters means all waters inside of 12 nautical miles from the coast, including all internal waters (i.e., lakes, bays, sounds, and rivers). The second set of regulations applies to lightering in all offshore waters, except for designated lightering zones. Offshore, for this purpose, means between 12 and 200 miles off the coast. The third, and most comprehensive, set of regulations applies in designated lightering zones that are more than 60 miles off the coast. The Coast Guard does not regulate lightering in foreign waters or outside the U.S. Exclusive Economic Zone (EEZ). Technically, lightering in offshore waters is subject to regulation by the Coast Guard only when the cargo is bound for a U.S. port. As a practical matter, though, all oil lightered in U.S. waters is bound for the United States. Under the comprehensive national lightering regulations, four areas are designated lightering zones (offshore) in the Gulf of Mexico.

In general, lightering is performed with the local USCG captain of the port (COTP) exercising regulatory authority. The regulatory regime for lightering is widely regarded as adequate, with one notable exception. Industry representatives informed the committee that vessels sometimes have to maneuver

excessively or separate prematurely to comply with a legal provision that requires certain vessels to remain within designated lightering zones in the Gulf of Mexico except in emergencies.

Industry guidelines for lightering have been established by at least two industry groups, and most individual companies have developed their own internal guidelines. A set of comprehensive minimum standards for offshore lightering, now in its third edition, has been developed by the Oil Companies International Marine Forum (OCIMF), an international group of vessel owners and charterers. The guidelines contain advice on lightering procedures and arrangements, as well as specifications for mooring, fenders, and cargo transfer hoses. The shipping industry relies heavily on the OCIMF guidelines, although anecdotal evidence and the observations of committee members suggest that the guidelines are not applied uniformly. In the United States, a supplement to the OCIMF guidelines was developed by the Industry Taskforce on Offshore Lightering (ITOL), a highly effective cooperative organization that promotes industry self-policing and, in partnership with the USCG, continuous improvement in lightering in the Gulf of Mexico.

The OCIMF guidelines are also widely used for U.S. inshore lightering. General standards for inland shipping have been established by the American Waterways Operators (AWO), but no separate lightering standards have been established for inland trade despite its unique characteristics, such as the extensive use of barges and the frequent transport of specialized refined products.

The OCIMF and ITOL lightering guidelines leave little room for improvement, with the exception of a few details concerning the characteristics of the safest vessel designs and equipment. Procedural issues requiring special emphasis include measures for ensuring that key vessel personnel are fluent in English and that the safest methods are used for gauging cargo following a lightering operation.

The committee also paid particular attention to human factors in its investigation of spill risks and noted that the training and certification of all personnel engaged in lightering are critical to safe operations. The international maritime industry has recently adopted a new convention on training and certification for seafarers that represents a milestone for enhancing the skills and competency of shipboard personnel in the international fleet as a whole. In addition, the committee found that the lightering industry's training programs and qualification requirements for mooring masters and other expert advisors are based on high standards and rigorous oversight. These programs and requirements should continue to serve as a sound model in the future.

The safety of lightering depends heavily on the information available to shipping and lightering companies and vessel personnel. The committee identified

three major gaps in the availability, appropriateness, and accuracy of the information that is readily available for lightering purposes.

First, one of the major variables in lightering is the condition and performance of the STBL and its operators. Although information about the condition of a vessel can be obtained from the owner/operator, lightering companies do not currently have direct access to the more comprehensive, vetted information in the SIRE² database, an oil industry initiative that facilitates the sharing of data on vessel condition among OCIMF members. Second, the current systems for providing marine weather forecasts in the United States do not fully meet lightering needs. Reported problems include the inappropriate location of weather buoys, a lack of real-time information, and delays in repairs of buoys and data links. Third, to avoid anchoring on and damaging underwater oil pipelines in the Gulf of Mexico, the operators of STBLs and service vessels need accurate data on pipeline locations. Federal agencies do not currently collect and publish these data on a timely basis.

The sound safety record of lightering in U.S. waters, combined with the strong preference of the maritime community for self-regulation, suggests that most measures aimed at reducing the risk of spillage would be best performed by the industry. Accordingly, 10 of the committee's 16 recommendations are addressed to shipping and lightering companies and organizations. The remaining six recommendations, which require national leadership or intersect with agency missions, are addressed to the USCG and other federal agencies.

Recommendation 1. Industry organizations, such as the American Waterways Operators, or cooperative organizations modeled on the Industry Taskforce on Offshore Lightering should develop standards and guidelines for inshore lightering operations. This document could either supplement or incorporate appropriate sections of the Oil Companies International Marine Forum guidelines for offshore operations.

Recommendation 2. Chartering organizations should screen all prospective ships to be lightered to determine whether they meet Oil Companies International Marine Forum standards for vessels, equipment, and crews and should not charter vessels that do not meet these standards. As a supplementary measure to

determine whether this self-policing process is effective, the U.S. Coast Guard should monitor the process and call for periodic reports when appropriate and needed.

Recommendation 3. The Oil Companies International Marine Forum should consider making limited revisions to its Ship Inspection Report regulations to give lightering companies access to information on the condition of vessels.

Recommendation 4. To promote the adequate rigging of secondary fenders, the Oil Companies International Marine Forum should emphasize (e.g., in the next edition of its lightering guidelines) the need for vertical and flat surfaces as high as possible along vessel sides above the load waterline, with the maximum amount of vertical sides consistent with design requirements. In addition, mounting points, leads, and lifting equipment for secondary fenders should be positioned and sized for optimum effectiveness, and leads and securing facilities should be provided for primary fenders to ensure maximum coverage.

Recommendation 5. The Oil Companies International Marine Forum should focus on the need for vessels to have enough full-sized mooring bitt and enclosed chocks to secure the two vessels together with a minimum of four lines forward and aft. A minimum of one full-sized mooring bitt and enclosed chock should be provided within 35 meters forward and aft of the manifold. All mooring lines should be secured by winches.

Recommendation 6. The Oil Companies International Marine Forum should focus on the need for vessels that are capable of slow steaming for extended periods of time (within the limited operating range of modern diesel engines) with fine control of engine revolutions to enable safe maneuvering during mooring and unmooring operations.

Recommendation 7. The Oil Companies International Marine Forum should recommend limited operating parameters for modern double-hull tankers used as ships to be lightered to accommodate excessive freeboard (up to about 85 feet) when the cargo tanks are empty, a condition that can degrade the integrity of the mooring between the ship to be lightered and the service vessel. At the same time, the International Maritime Organization should consider modifying MARPOL. Annex I, Regulation 13 or classifying lightering as an "exceptional case" to permit greater ballasting of these vessels when transferring oil to a service vessel.

Recommendation 8. Mooring lines should be fitted with synthetic tails and fenders designed specifically for lightering operations. Lightering operators

should also adhere carefully to existing standards and guidelines with regard to the inspection and testing of hoses.

Recommendation 9. Before initiating cargo transfer operations, the mooring master (or equivalent person in charge) aboard the service vessel should determine whether the key individuals on the ship to be lightered are fluent in English and can understand the lightering plans and respond to commands. If necessary, an individual (reporting to the lightering master or other official in charge of lightering) who is both fluent in English and knowledgeable about lightering should be put aboard the ship to be lightered prior to the transfer of cargo.

Recommendation 10. To limit the time that vessels are alongside each other in a seaway and avoid delays in departure under adverse or marginal weather conditions, the Industry Taskforce on Offshore Lightering should suggest (e.g., in the next edition of its offshore lightering guidelines) that the mooring master and vessel master dispense with the inspector's gauging (at least on the service vessel) until the vessel is in port. If cargo quantities must be ascertained offshore, gauging should be limited to the ship to be lightered and should be done after the service vessel has departed. The cargo measurements for the service vessel could be telexed to the ship to be lightered.

Recommendation 11. The U.S. Coast Guard should encourage the lightering industry on the east and west coasts to adopt or adapt the Industry Taskforce on Offshore Lightering model as part of their program to promote problem solving, interaction, and cooperation to enhance safety and environmental protection. Cooperative arrangements could be initiated through existing mechanisms, such as the American Waterways Operators/U.S. Coast Guard Safety Partnership.

Recommendation 12. The U.S. Coast Guard, in consultation with the lightering industry, should work with the National Weather Service and the U.S. Navy to select locations for weather buoys and to tailor weather data and forecasts to support operations in both designated lightering zones and traditional lightering areas. The National Weather Service should take on this task as a priority to improve the delivery of weather information for offshore operations.

Recommendation 13. The U.S. Coast Guard captain of the port should be given the authority, based on a case-by-case review of individual requests and circumstances, to allow vessels to leave designated lightering zones for safety reasons while still engaged in lightering.

Recommendation 14. The U.S. Coast Guard should develop, or hire a private contractor to develop, an accurate, comprehensive computer database on maritime oil spills that can be searched and sorted by pertinent variables, including the causes of accidents.

Recommendation 15. The Minerals Management Service (of the U.S. Department of the Interior) and the Office of Pipeline Safety (of the U.S. Department of Transportation) should develop and implement a plan to collect and compile accurate data on the location of pipelines in the Gulf of Mexico and make the information available to the operators of vessels that engage in lightering. Priority should be placed on data collection in designated lightering zones and traditional lightering areas, and the data should be verified and updated on a regular basis.

Recommendation 16. To ensure safe anchorages amid the increasing oil and gas exploration activity, the U.S. Coast Guard should seek authority to designate "pipeline-free areas" where new pipelines cannot be laid.