TL: Position Paper on IMO Debate Re: Tank Vessel Design (GP) SO: Greenpeace International DT: 2-6 March 1992 Keywords: oceans oil tankers greenpeace groups gp factsheets / Prepared by Greenpeace International for Informal Distribution at MEPC/32 IMO, London Executive Summary The nations of the world must end, as soon as possible, their addiction to oil and other fossil fuels, given the devastating environmental and other impacts and risks of such energy sources. IMO, through bodies such as MEPC, should pursue every opportunity to find constructive and creative ways to help with this effort. At the same time, it is important that MEPC take any and ail possible steps in an effort to ensure the environmentally safe maritime transport of oil. Despite international efforts to eliminate marine pollution from the shipment of oil, spills are on the rise both in terms of numbers of spills and the total amount of oil spilled. Now is the time to institute design and construction requirements for safer shipping. Delegations participating in MEPC/32 should seize the opportunity to provide for safer transport of oil for the benefit of the marine environment. Draft Regulation 13F of Annex I of MARPOL provides the opportunity to achieve significant progress in that direction. That regulation needs to be improved by providing strong standards for design of double hull tankers, including provisions for adequate inner hull spaces, longitudinal structure, tank size, and strength of hull plating, as well as strong requirements for sustaining side and bottom raking damage. Despite the work of the IMO's Steering Committee on Oil Tanker Design (OTD), it has not been demonstrated that the mid-deck design offers pollution protection "equivalent" to a double hull vessel. Flaws in the procedure and methodology used for the study raise serious doubts about its results. New information suggests the analysis grossly underestimates oil outflow from mid-deck designs and overestimates oil outflow from double hull designs. Reliance on potential aggregate oil outflow in collisions and groundings as a measure of equivalency is misplaced. A major shortcoming of the OTD Study is its failure to include structural behavior of the vessel as a factor contributing to oil outflow. Structural failure is particularly important when making the comparison between double hull and mid-deck designs because failure of the mid-deck will eliminate the alleged advantage of that design in high energy incidents. In tandem with a 13 F double hull mandate, the draft regulation 13G provisions establishing a phase out of single hulled tankers and rigorous interim measures are necessary to discourage extension of the life of those tankers. An expedited phase out or retrofit of all existing vessels is required, especially for older, single hulled vessels. Rigorous interim measures also should be required for existing vessels, including a prohibition from carrying cargo within their wing tanks, required use (where appropriate) of hydrostatic balanced loading (HBL), and incorporation of a distressed ship cargo transfer system. Greenpeace International Position Paper on IMO Debate Re: Tank Vessel Design I. The Need to Eliminate Oil as Source of Energy While the subsequent sections of this position paper address the 13F/13G issues related to tank vessel design and construction that are now before MEPC/32, this introductory section seeks to provide a broader context for those comments. The International Maritime Organization, established in 1948 by the UN Maritime Conference, is the principal international body for maritime matters. of the more than 30 international agreements for which IMO staff provide secretariat services, many of those address issues related to the transport and handling of fossil fuels, especially oil and petrochemical products. With 135 Member States, as well as observers from UN agencies, industry trade associations, environmental and other non- governmental organizations (NGOs), the IMO has the opportunity and responsibility to play a major role in addressing maritime aspects of important issues facing the global community. In this regard, a critical issue facing the world's decision makers is the growing threat to the environmental security of the planet due to the use of fossil fuels, especially oil. Oil has played a dominant role in the economics and politics of the 20th century. But past, present and projected environmental damage shows that continued reliance on oil will result in a grievous assault on the marine, terrestrial, and atmospheric environments on which humans and other species depend. The current assault on the atmosphere poses a particularly grave threat to environmental security. According to the great majority of the world's climate scientists, business-as-usual reliance on fossil fuels (oil, coal and gas) is likely to generate catastrophic global warming in the decades to come. If current trends are allowed to continue, the concentration of CO2 and other "greenhouse gases" will more than double by the middle of the next century. The most likely consequence of such a trend will be a rise in the global average temperature of 2-4 degrees C over the next sixty years -- a rate of temperature change unprecedented in human history. Such rapid changes are predicted to have devastating social and environmental impacts. If there is to be any confidence that the world environment and its dependent human societies are to avoid catastrophe, a program of concerted international action is required to reduce emissions of greenhouse gases. It is unprecedented both in scale and urgency. Nowhere is action more essential than in ending the present world addiction to oil and other fossil fuels. Yet the threat of climate change is not the only serious environmental problem posed by the present world energy sector. The burning of fossil fuels also produces air pollutants which are wreaking a tragic and costly toll on human health, damaging forests, reducing crop yields and eroding national monuments and buildings, and its transport at sea results in the annual discharge of 3 to 4 million tons of oil to the world's oceans, among other adverse effects. For all the above reasons, the nations of the world must end, as soon as possible, their addiction to oil and other fossil fuels. The IMO, through its treaty regimes and Member State decision making bodies, should pursue every opportunity within its remit to find constructive and creative ways to help with this effort. Among other steps, the IMO's adoption of more stringent tank vessel design, operational (e.g, the air pollution/fuel oil quality issues before MEPC) , and personnel requirements and other measures could assist in moving towards a more proper allocation of the real costs associated with the marine transport of oil. Steps also should be taken to much more effectively factor in the adverse societal, economic and environmental costs associated with marine-related aspects of fossil fuel use. These and other steps could serve as part of a much, much broader effort by the world community to move rapidly away from the use of oil and other fossil fuels, and toward renewable energy, efficiency and conservation. II. Need for Safer Transport of oil Despite international efforts to eliminate marine pollution due to the shipment of oil, oil spills are on the rise both in terms of numbers of spills and the total amount of oil spilled. Data compiled by the Tanker Advisory Center, Inc. confirms this trend. (Table 1). In the first half of 1991 alone, 425,000 tons of oil were spilled. This is up from 8,700 tons spilled in 1987, and 5,000 tons spilled in 1986. Between 1983 and 1988 the number of major spills reported to Lloyd's did not exceed 17 per year. In contrast, 31 spills occurred in 1989, and 31 again in 1990. It has been recognized that vessel age is directly linked to accidents involving substantial oil outflows. There is evidence that older vessels have more accidents, particularly those due to fires or explosions and structural failure. Studies show a tanker 15 years old has three times the probability of structural failure as a vessel 10 years old. Given the currently aging world tanker fleet, and in the absence of concerted action, it is reasonable to expect an increase in tank vessel accidents resulting in oil spills and consequent pollution. The environmental consequences from oil spills can be devastating. oil spills cause both short term ("acute") and long term ("chronic") impacts on the environment. Many of these effects are not well understood or sufficiently documented by the scientific community. However, it is well recognized that spills in biologically rich areas will result in the immediate deaths of marine mammals, seabirds and fish. In addition, it is anticipated that other subtle chronic impacts on the environment will persist over many years, impacting on reproductive success of some species, as well as food sources. From an environmental perspective, a large number of small spills may present concerns equal to or greater than the highly publicized large spills. Indeed, recent studies have shown that adverse effects on marine life exist from exposure to oil at the low rate of only several parts per billion. A. Need for Improved Operations/Personnel Training/Enforcement The safe transport of oil depends upon diligent operation and maintenance of vessels, as well as competency of crew. Efforts to improve crew training, ensure adequate crew size and to encourage consistent attention to proper operation/maintenance are necessary to insure against accidental oil spills. Establishing stringent standards must be coupled with frequent monitoring and inspection by regulatory authorities. In addition, ongoing enforcement of regulatory requirements and stringent penalties for non-compliance will further encourage high standards and should result in safer shipment of oil. Policies also should be developed to ensure that owners/operators of vessels are required to act without delay in accepting assistance from state- controlled professionals or private state-approved professionals when a spill (or threat thereof) occurs. Further, as noted in Part I, above, proper allocation of real costs associated with the transport of oil, and particularly as regards the costs of accidental spills, would encourage diligence on the part of shipowners and charterers to ensure safe transport. Among other things, this requires adherence to the polluter pays principle, which, in this context, would translate into adoption of a joint, several, strict and unlimited liability regime for the transport of oil. Such a regime would ensure that the responsible parties would begin to bear the immeasurable costs of a spill. B. Need for Better Design/Structure While efforts to improve these aspects of international shipping are critical and should be continued, it is equally important to use ship design as a basis for improving pollution prevention capabilities. Other measures are largely subject to human error, which is often the original cause of accidental spills. By building pollution prevention features in the design of a ship, it is possible to provide a secondary safeguard against pollution. As noted in the U.S. National Research Council (NRC) Study entitled, "Tankers Spills - Prevention by Design," ship design practices to date do not consider prevention of oil outflow from groundings and collisions as a basis for design standards. Indeed, new design techniques have rendered modern tankers less robust, by reducing "safety factors" to minimize costs and to get maximum deadweight for minimum draft, enabling the ship to carry more cargo. This has led to increased vulnerability to failure in the face of fatigue, inadequate maintenance or unusual structural stress. In sum, design practices should be revised to account f or the probability of collision or grounding. Draft Regulation 13F provides the opportunity for the international community to achieve significant progress in that direction. III. 13F -- New Tank Vessels Draft regulation 13F of Annex I of the International Convention for the Prevention of Pollution From Ships (MARPOL), as proposed, will not provide adequate environmental protection, for two reasons. First, draft 13F does not provide for properly designed double hull tankers. Second, the mid-deck tanker does not provide pollution prevention protection "equivalent" to that of the double hull. A. Double Hull Provisions of Draft 13F Should be Strengthened While a double hull mandate for oil tankers is needed, it is critical that such tankers be properly designed. The 13F requirements for double hull tankers must be strengthened to ensure a high degree of protection. In particular, provisions regarding the size of inner hull spaces and damage stability (raking damage) should be revised. In addition, provisions regarding longitudinal structure, tank size, and strength of hull plating should be seriously considered for inclusion in 13F. (1) Size of double hulls The inner hull spacing proposed in 13F is inadequate. At minimum, the side hull spacing on ships should be B/15 or 2 meters, whichever is greater. Likewise, bottom hull spacing should be B/15 or 3 meters, whichever is greater. The upper limit of 2 meters for inner hull spaces as proposed in 13F is not justified. It has been suggested that increased double bottom height is particularly effective in preventing spills. A Det Norske Veritas analysis provided for the NRC showed a 41.7% probability that no oil would leak from a grounded VLCC with a 2 meter double bottom. A three meter double bottom would increase that probability to 69%. Larger double bottom heights required by a B/15 standard create legitimate concerns about accessibility for inspection. The solution, though, is to require double bottoms of greater than 3 meters to contain permanent fixed access to ensure adequate inspection. If such access were provided, it would not be necessary to compromise environmental safety. (2) Damage stability As regards damage stability, the criteria should be revised to ensure that double hull tank vessels are not less stable following damage than single hull vessels. Of particular concern is the possibility of capsize of a double hull tanker which experiences raking damage. Double hull vessels should be required to sustain bottom raking damage of 1.0L of the longitudinal extent of the vessel rather than .75L as proposed in draft 13F. This recommendation is supported by data provided in Annex 1 of SLF 36/INF.15. In addition, 13F should require double hull vessels to sustain side raking damage of at least .5L. This recommendation is supported by data presented in Annex 1- of SLF 36/INF. 15. The data provides two instances where side damage exceeds .5L. Such requirements will reduce the likelihood of catastrophic consequences of a capsize. (3) Longitudinal bulkheads It was noted in the IMO Comparative Study that double hull vessels without centerline bulkheads have the potential for much greater oil outflow than those double hull vessels which have centerline bulkheads. Annex I regulations should, therefore, include a provision requiring longitudinal bulkheads in cargo holds or alternative cargo tank arrangements to limit oil outflow. (4) Other considerations MEPC should give further consideration to limiting cargo tank size, increasing scantlings, and requiring minimum hull plating thickness as other means for strengthening the pollution prevention capabilities of double hull tankers. In addition, consideration should be given to development and installation of constant monitoring systems in, all void spaces for timely detection of any leakage or development of gases. At the same time, requirements should be adopted for increased inspection and maintenance of all void and inner hull spaces. In particular, the minimum thickness criteria for outer and inner plates needs to be established promptly and, in the interim, the minimum should be no less than the outer plate thickness required of new single hull vessels. Outer and inner hull minimum thickness each should be greater than what is currently required of single hull vessels. In order to be a true "double hull", the inner and outer hulls should be of the same thickness. B. The "Mid-Deck" Design Does Not Provide Pollution Protection Equivalent to a Double Hull Tanker Draft 13F's characterization of the mid-deck tanker design as providing pollution protection "equivalent" to a double hull vessel is inappropriate. To date, the MEPC's attempt to resolve debate over equivalency of the two designs through the IMO Comparative Study on Oil Tanker Design (OTD Study) has failed to do so. Instead, significant flaws in the procedure and methodology used for the study raise serious doubts about the validity of its results. In addition, the interpretation of those results by the Steering Committee (with the exception of the one (FOEI) environmental representative on the Committee) reflects a rather limited understanding of environmental consequences arising from oil spills. The following is a more detailed explanation of these concerns. (1) Flaws in the OTD study process The OTD Study suffered from the outset by the absence of agreed upon criteria by which to make a comparison. Specifically, there is no agreed upon definition of "equivalency" for the purpose of comparing the two designs. The OTD Study report appears to adopt potential aggregate oil outflow as the key factor in determining equivalency. As discussed further below, this standard may not be the best indicator of environmental protection. It appears that significant confusion has been caused by MEPC's failure to properly instruct the OTD Steering Committee. MEPC requested a determination of equivalency without first defining that term. In the absence of such a definition, it was inappropriate for the Steering Committee to make the determination. It is now incumbent upon MEPC to rectify the problem by defining what is meant by equivalency and reassessing the data on that basis to make a comparative determination. The OTD Study also suffered because of a hasty time frame. The Steering Committee was asked to undertake an enormous task in only a four-month period. The amount of work accomplished was impressive. However, as noted below, key factors necessary to make a credible comparison are missing from the analysis. Presumably a longer time frame for gathering and processing data would have enabled the Committee to fill those gaps and produce a more reliable analysis. The hasty time frame also forced the Committee to reach conclusions before all of the analyses were in, which contributed to the confusion about the results of the Study and its interpretation. Indeed, additional tests performed after the Committee prepared its report refute basic assumptions of the analysis and call into question the report's conclusions. (2) Flaws in the OTD Study data base and methodology A major shortcoming of the OTD Study is its failure to include structural behavior of the vessel as a factor contributing to oil outflow. Structural failure resulting from a grounding or collision is particularly important when making the comparison between double hull and mid-deck designs because failure of the mid-deck will eliminate the alleged advantage of that design in high energy incidents. As noted below, historical data suggests that the mid-deck itself is not likely to remain intact in the event of a high energy grounding, rendering such a ship "equivalent" to a single hull tanker as regards oil outflow. A greater understanding of structural behavior is called for in the NRC Study. Specifically, it is suggested that improved analytical techniques are required to understand the hull rupture initiation process and improved capabilities for predicting vertical, lateral, and horizontal extent of damage sustained to ship bottom. The OTD Study consideration of structural failure as a cause of an accident and its consideration of residual strength did not encompass the factor of structural behavior/failure in the wake of an impact. The OTD Study should have attempted to answer the question: Under what conditions will a mid-deck tanker suffer fractures or cracks above the waterline, rendering the mid-deck ineffective? Failure of the OTD Study to answer this question and account for this factor in its analysis renders the conclusions highly suspect. The OTD Study report points out in para. 5.2.3 that the analysis does not use probability functions for all of its assumptions. Recognizing that it may be difficult to provide probability functions for all of the assumptions because of a lack of reliable statistical data, this represents another major shortcoming of the analysis. Use of single values representing a "typical" accident scenarios weakens reliability of the results. The problem is clearly demonstrated by the debate over the percent of oil outflow from a mid-deck tanker in the initial exchange. The original analysis assumed a 1% initial outflow. Subsequent tests demonstrated that this value is directly linked to speed of the vessel upon impact. At the time this paper was prepared, there had been no effort to gather the necessary data on speed of ship at time of grounding to resolve this issue. Choosing a single value for this parameter is not sufficient to produce a reliable result. (3) Limits of the model tests The OTD analysis relies heavily on model tests performed by Tsukuba Institute and David Taylor Research Center (DTRC) . These models fall far short of simulating reality and are easily manipulated to produce desired results. The size and uniform configuration of "rupture" holes, the use by Tsukuba Institute of a model with "J" tanks being portrayed as having "U" tanks, as well as problems in properly maneuvering the models and regulating movement of the water in the tank, render the results highly suspect and of limited value. For the purpose of argument, however, one can also look to new information from the DTRC, and other sources to challenge the conclusions of the OTD Study report. (4) New information refutes original OTD results New information which became available after the OTD Steering Committee had agreed on a final report appears to refute basic assumptions of that analysis and directly challenge the finding of equivalency between mid-deck and double hull tankers. Specifically, additional tests performed by DTRC refute original assumptions and findings of the OTD report. In addition, an analysis by Environmental Computer Optecnomics (ECO) of Annapolis, Maryland suggests the importance of structural concerns vis-a-vis the mid-deck design. First, the DTRC model tests suggest that the original assessment of the performance of a mid-deck tanker in a low energy grounding is flawed. The initial exchange loss of 1% as used in original analysis is too low. The DTRC model tests demonstrate that the initial exchange loss is largely a function of speed, and at speeds between 7.5 kn and 14 kn the value would be in the 3 - 10% range. Ideally, a probability function should be determined (using speed at time of grounding from historical data) for use in the computer analyses. Noting that the Exxon Valdez grounded at 12 kn, a value closer to 14 kn should be used if the analysis is to be limited to a single value. While presumably ships should be travelling at slower speeds in near shore waters, the Exxon Valdez demonstrated that this is an invalid assumption. Absent historical data to confirm slower speeds as customary, a higher value should be used. The original OTD conclusions based on a 1% initial exchange loss therefore tend to underestimate the amount of oil spilled from a mid-deck tanker in low energy groundings. Assuming a larger value for initial exchange loss may or may not have a dramatic effect on the difference between mid-deck and double hull designs as regards overall oil outflow. It is particularly significant, however, with respect to those 80% of the grounding incidents where no oil would be spilled from a double hull tanker. The almost immediate loss of three to ten times more oil than originally assumed in the OTD Study is dramatic. Even a 4% loss from a VLCC cargo tank translates into about 400 tons of oil -- a relatively large spill which should be prevented by use of a double hull. It also should be noted that the final tests performed at DTRC substituted new variables for size of rupture hole and also performed tests with the tanks in a "half-load" condition. Rather than decreasing the size of the rupture hole, the tests should have been run using larger holes. Second, the assessment of the oil outflow from a double hull vessel in a high energy incident appears to be overestimated. The original OTD analysis does not adequately account for effects of blockage in the double hull, resulting in capture of oil in the inner hull spaces. The assumption of the original analysis is that the quantity of oil held in the double hull space is equal to 50% of the volume of the double hull space from the bottom up to the height corresponding to the level reached by the oil in the cargo tanks when static equilibrium is attained. Model tests performed by DTRC, simulating only 50% blockage of the rupture opening, showed virtually no oil loss to the ocean. On the basis of this finding, and given the fact that blockage would be the more typical occurrence for a double hull vessel, in most instances the quantity of oil held in the double hull space is likely to well exceed 50%. Therefore, the amount of oil assumed to escape from a double hull tanker in high energy incidents is largely overestimated. Finally, the assessment of the performance of a mid-deck vessel in high energy incidents may be seriously flawed. ECO examined data from six major grounding incidents which showed in all six instances that the outer hull and longitudinal bulkheads were cracked with the cracks extending above the water line. This finding strongly suggests that the integrity of the mid-deck itself quite vulnerable. Loss of integrity of the mid-deck is critical because such a loss would result in loss of the pressure advantage assumed in the mid- deck design. Loss of that hydrostatic pressure renders a mid-deck equivalent to a single hulled tanker in the event of a grounding. In addition, oil losses due to structural failure could occur in relation to tidal variations, especially where those variations are dramatic. On this basis, there are strong grounds for suspecting that the OTD Study grossly underestimates the oil outflow from a mid-deck vessel in a high energy grounding. (5) Conclusions of OTD Study should be revised As noted above, before a valid comparison can be made between any two designs there must be some agreement on criteria for determining "equivalency." The overall volume of oil spilled alone is not an appropriate standard for assessing equivalency with regard to pollution protection. The number of spills prevented is also an important factor. There also is cause for concern with respect to the 80% of groundings that would not result in spills by double hull ships, but would result in "some" amount of oil being spilled by mid-deck vessels. However, that amount appears to be underestimated in the OTD Report. Absent a credible analysis of structural behavior of a mid-deck vessel in the context of groundings, the finding that a mid-deck tanker will perform better than a single hulled tanker in a high energy grounding is unconvincing. When these considerations are taken into account, the mid-deck design is not "equivalent" to a double hull tanker. Rather, the double hull should be the preferred design overall, since it has not been demonstrated that a mid-deck design is an acceptable substitute. IV. 13G -- Existing Tank Vessels Given the double hull mandate of draft regulation 13F, draft regulation 13G provisions establishing a phase out of single hulled tankers and rigorous interim measures are necessary to discourage extension of the life of older single hulled vessels. An expedited phase out or retrofit of existing vessels is required. Other interim measures should be implemented as suggested by draft 13G. A. Expedited Phase Out The time is ripe for implementing progressive new ship design standards. The average age of the world fleet is 14. The average age is greater in some areas of the world. For example, the average age of the Alaskan fleet is 19. These aging tankers pose a greater risk each day. Owners must begin to consider replacing these vessels regardless of new design mandates. Indeed, the large tonnage of tankers built in the mid-1970s are expected to be out of service during this decade. For this reason, now is the time to adopt a double hull mandate and other new design measures to enhance the safety of the tanker trade. Proposals currently before MEPC to establish a phase out schedule are inadequate. To remedy this, the phase out of older ships should begin immediately, with the current fleet being brought into compliance on an expedited schedule. Surveys of the world's current shipyard capacity, and anticipating some increase in such capacity, suggests it may be possible to complete a phase out by 2005 or earlier. The Tanker Advisory Center, Inc. estimates that there is currently a 40,000,000 DWT surplus tanker tonnage in the world. This surplus provides a comfortable buffer to prevent against disruption of the trade during the phase out. B. Interim Measures Strong interim measures for existing single-hull vessels pending the phase in of double hulls are vital to ensure increased protection from oil spills during the intervening years. Such measures must be stringent to discourage owners from extending the life of older vessels. First, all single hull vessels should be prohibited from carrying cargo within their wing tanks. The wing tanks are the most vulnerable to damage from hull penetration. This is due in part to the fact that twenty to forty per cent of a vessel's bottom underlies the wing tanks. As a study of 28 oil spills from tankers and combination carriers of 10,000 tons reported in Lloyd's List for the years 1988 and 1989 demonstrated, two-thirds of the oil spilled from tankers sustaining hull damage and penetration came solely from wing tanks. For this reason, oil should not be carried in the wing tanks of single hull vessels. Hydrostatic balanced loading (HBL) is an interim measure that should be given careful consideration and should be required for existing ships under certain circumstances. Admittedly, HBL is not a foolproof measure for limiting volumes of oil spilled, since it is not reliable in real world situations where changing tides and varied current patterns can substantially diminish the advantages of such loading. While this limitation makes HBL unsuitable for new construction (since structural requirements are more reliable), it is worthy of consideration for existing ships. Clearly, the effectiveness of hydrostatic control depends on operators' strict adherence to rules, rather than on a permanent feature of vessel design and construction. Some regulatory effort must therefore be made to ensure that hydrostatic balanced loading is properly achieved prior to a vessel leaving port. Hydrostatically loaded ships face greater complications regarding multiple ship discharges and loadings. If such complications can be overcome - perhaps by increased regulatory control over discharges and loadings of such vessels - then HBL should be required for existing ships. This and other potential problems of stability associated with use of HBL should be referred to the Marine Safety Committee for advice. A distressed ship cargo transfer system also should be required for installation on all existing ships. When vessels are involved in grounding situations, cargo. systems are often rendered useless. Efforts to pump cargo from a breached tank are futile when the suction is at the bottom of the tank. Portable pumps must be flown in and complete lightering can take a week or more. All vessels should be required to install an emergency cargo transfer system to enable the rapid transfer of cargo from damaged tanks to intact tanks or a lightering vessel. Such a system should have suction points at several depths. Piping should run through secure sections of the vessel where it will be protected in the event of an accident. An independent power source for the cargo transfer system is also recommended. IV. Conclusion As discussed at the outset of the position paper, the IMO needs to pursue every opportunity to reduce and eliminate the use of oil and other fossil fuels as energy sources. At the same time, it also is important that IMO, through bodies such as MEPC, take' any and all possible steps in an effort to ensure environmentally safe maritime transport of oil. The basic intent of draft regulation 13F and 13G is well founded. However, those drafts can and should be improved. Draft regulation 13F needs to strengthen the double hull requirements and eliminate the mid-deck tanker design as an equivalent alternative to double hulls. 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