The Coulombi Egg Oil Tanker - United States Coast Guard
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The Coulombi Egg tanker was approved by the IMO September 1997. Immediately afterwards USA via USCG admiral Kramek declared that no Coulombi Egg tanker would be allowed in the USA!

The Coast Guard Authorization Act of 1998 however mandated the Secretary of Transportation to commission the Marine Board of the National Research Council's (NRC) Transportation Research Board (TRB) to develop a rationally based approach and method for assessing the environmental performance of alternative tanker designs relative to the double-hull standard.

The result was Special Report 259 'Environmental Performance of Tanker Designs in Collision and Grounding: Method for Comparison' issued by the Transportation Research Board. It can be read here!

The Coulombi Egg tanker had previously briefly been discussed at the US Congress.

Under the auspices of the Marine Board, the NRC convened an 11-member Committee on Evaluating Double-Hull Tanker Design Alternatives with appropriate scientific and technical expertise in risk assessment, tanker design, tanker operations, crashworthiness of ships, and costs and damages (including environmental damages) related to oil spills. The recommendations of the committee are at the bottom of the page. Heiwa Co supports all recommendations. Soon the COULOMBI EGG tankers can sail to the USA!

The committee as a whole met five times between June 1999 and January 2001, and subgroups met periodically throughout that time. The early meetings included extensive presentations in sessions open to the public, during which experts from government, academia, and industry described a variety of issues and views for the committee. The final report represents a synthesis of the information gathered by the committee, which encompassed the data, analytical tools, and simulation methods currently available for the development of a rationally based approach for assessing the environmental performance of alternative tanker designs relative to the double-hull standard. Unfortunately Heiwa Co was neither informed about nor invited to any sessions of the committee.

Committee members had extensive experience in the day-to-day operations of all relevant technologies, as well as in the overall analysis of operations and risks and in systems management.

The 11 members of the 'Committee on Evaluating Double-Hull Tanker Design Alternatives' were:

Kirsi K. Tikka, Chair, Professor of Naval Architecture, Webb Institute, Glen Cove, New York
Peter F. Bontadelli, President, PFB and Associates, Sacramento, California
John M. Burke, Mobil Shipping and Transportation Company (retired), Vienna, Virginia
Paul S. Fischbeck, Associate Professor, Carnegie Mellon University, Pittsburgh, Pennsylvania
Alan G. Gavin, Manager, Technical Planning and Development Department, Lloyd's Register of Shipping, London, United Kingdom
Sally Ann Lentz, Executive Director and General Counsel, Ocean Advocates, Clarksville, Maryland
J. Randolph Paulling, Professor Emeritus of Naval Architecture, University of California, Geyserville, California
Dragos Rauta, Technical Manager, INTERTANKO, Oslo, Norway
Philip G. Rynn, Senior Staff Consultant-Engineering Management, American Bureau of Shipping, Houston, Texas
Robert Unsworth, Principal, Industrial Economics, Inc., Cambridge, Massachusetts
Luther W. White, Professor of Mathematics, University of Oklahoma, Norman, Oklahoma

They were assisted by the following Transportation Research Board Staff:

Beverly M. Huey, Study Director, Transportation Research Board
Peter Johnson, Consultant, Transportation Research Board
Susan Garbini, Senior Program Officer, Transportation Research Board
Donna Henry-Rahamtalla, Project Assistant, Transportation Research Board

Sponsoring Liaisons persons were:

H. Paul Cojeen, Chief, Naval Architecture Division, United States Coast Guard, Washington, D.C.
David A. DuPont, Project Manager/Analyst Standards Evaluation and Analysis Division, United States Coast Guard, Washington, D.C.

Other Agency Representatives were

David Chapman, National Oceanic and Atmospheric Administration
Thomas Jordan, United States Coast Guard
Alexander C. Landsburg, Maritime Administration
Tony Penn, National Oceanic and Atmospheric Administration
James Person, United States Coast Guard
LCDR Jess Riggle, United States Navy
LCDR Jeff Stettler, United States Navy

None of the above has ever contacted Heiwa Co to find out the latest developments about the only alternative design approved by the IMO as per Marpol I/13F(5) - the COULOMBI EGG tanker - from its designer and developer. However, Heiwa Co thanks them all for a good job done. It is the beginning of the approval of the COULOMBI EGG by the USCG.

Below follows a review of Special Report 259 'Environmental Performance of Tanker Designs in Collision and Grounding: Method for Comparison'.

U.S. law (OPA90) allows for the evaluation and approval of alternative designs that can be determined to have equal or better performance than the double hull in protecting the environment. To date, however, the United States Coast Guard (USCG) has not made that determination for any alternative design as no American methods exist. Therefore the COULOMBI EGG tanker design has not been reviewed by the USCG. The International Maritime Organization (IMO) rule Marpol I/13F mandates two equivalent designs - double hull design and the mid-height deck design and may approve alternative design under Marpol I/13F(5). The only such approved design is evidently the COULOMBI EGG oil tanker 1997, developed by Heiwa Co. The U.S. of A has not adopted Marpol I/13F. Heiwa Co believes that U.S. technical regulations regarding oil tankers should be more consistent with international law (Marpol I).

The U.S. Congress requested that the study under review be undertaken by a committee under the auspices of the Marine Board of the National Research Council's (NRC) Transportation Research Board to determine whether a methodology could be established for measuring the equivalency of alternatives to double-hull designs with regard to environmental performance. Congress made this request through the USCG Authorization Act of 1998, but specified that the investigation be conducted independently of past USCG policy on double-hull equivalency (even if many of the committee members had participated in previous investigations). The committee was charged to develop a rationally based approach for assessing the environmental performance of alternative tanker designs relative to the double-hull standard. The proposed methodology was then to be applied to double-hull tankers and alternative designs (e.g. the COULOMBI EGG ) to demonstrate that it could be used for an assessment. This was a good start - but the committee never applied its methodology to any alternative design. The USCG has not approved any alternative design, but the IMO has - the COULOMBI EGG tanker 1997. Why didn't the committee use the COULOMBI EGG design in its study?

The committee was asked to ensure that the proposed methodology would be applicable to conditions prevailing in U.S. waters. The committee's charge also included refining and adjusting existing tanker damage extent functions used for measuring the crashworthiness of tank vessel structures. In addition, the committee was to develop a generalized spill cost database and use this database in formulating a rationally based approach for the calculation of an environmental index. This is all very good.

It is stated in the report that a number of organizations have submitted proposed alternatives to double-hull designs to either the USCG (for the United States) or IMO (representing the international community), both of which have developed regulations addressing minimum tanker design standards.

As far as Heiwa Co is informed only one alternative tanker design has been submitted (1995) to the IMO for approval - the COULOMBI EGG tanker - and approval was granted 1997. No other design has ever been submitted to the IMO 1995-2002. The alternatives referred to are generally fanciful oil tank designs, which cannot realistically be incorporated in a real oil tanker - access, cleaning, ventilation, maintenance and safety, etc. of the ship are not considered.

The committee believes that the COULOMBI EGG design was proposed by the Swedish government (sic), but the Swedish government had nothing to do with the COULOMBI EGG design. A designer and developer of an alternative design must only ask one nation (full) member ot the IMO to sponsor the application at the IMO. The designer/developer must self prepare all the approval work. In this case the acting director Roger Sundström of the Swedish National Maritime Administration - Sjöfartsverket - asked - or proposed to - the designer (Anders Björkman) 1994 that Sweden should sponsor the application at the IMO. In fact Egypt had already agreed to sponsor it 1992, but it was agreed that using Sweden was easier - the original application could be in English in lieu of Arabic (both languages are however working languages of the IMO but the former is more used).

The writers of the report - the committee - state that several other concepts have been developed in the United States. However, none has been submitted to the IMO for formal assessment and possible approval and the committee does not wonder why. The reason is that the COULOMBI EGG design is no. 1! INTERTANKO concluded the same thing already in 1992.

The report correctly says that the IMO method of comparing designs is based on a formula that assigns relative weighting factors to three outflow parameters related to spill size (zero, mean, and extreme outflow) and that use of these weighting factors was based on IMO's decision to select a formula that would ensure the equivalency of the double-hull and mid-deck designs. This may be so. In reality the mid-deck design provided better collision protection than double hull (fewer spills) and had much lower total outflows in groundings (but more smaller spills) - the formula was a compromize. The IMO methodology uses historical distributions of ship structural damage of single hull tankers which were thought to be representative for double hull and mid-deck tankers and alternative designs built of steel. Designs based on innovative structural concepts would be given special consideration. However - in order to get approved - any alternative, new design has to virtually spill no oil at all in any accident - and this the COULOMBI EGG tanker achieves using an innovative arrangement of normal steel structure. You do not have to develop an innovative structural concept to eliminate spills - locate the cargo in a safe location (based on damage statistics) or so that it does not flow out in accidents and the problem is solved. Evidently conventional steel tanker structure should be used.

The committee has successfully tried to establish a methodology for comparing the environmental performance of alternative tanker designs by the development of a new approach. The methodology developed by the committee is divided into three main components: (1) structural damage and oil outflow calculation, (2) consequence assessment, and (3) design comparison. This is very good. It is old fashioned COULOMBI EGG tanker basic design concept.

For the first component, the committee selected scenarios (collision and grounding events) that represented conditions in U.S. waters, specifically in those areas with a high density of tanker traffic. It should have included explosions and fires also, but they might be too difficult to assess. Once the collision and grounding events had been identified, the committee used damage models to determine the structural damage and resulting outflow in each accident.

The second component of the methodology involves the assessment of consequences from an accidental spill. The committee used an environmental impact model that predicts oil fate and transport, and allows for random sampling of weather conditions on the basis of historical weather data. This model provides a number of physical consequence measures, such as the area of the sheen, the toxicity in the water column, and the length and area of oiled shoreline. The committee decided to limit the assessment of consequences to these physical measures instead of extending it to impacts on biological resources. Doing so would keep the analysis as systematic and well specified as possible without necessitating difficult decisions as to what threshold levels would damage biological resources and how those resources are valued.

In addition to the physical consequence measures, the committee considered several non-environmental measures of consequence, including spill cleanup and response costs, the value of lost product, and third-party damages. These measures were eliminated from the final analysis for several reasons. The value of lost product, measured on a per gallon basis, is not expected to vary significantly with spill size. More important, the collective best judgment of the committee was that the physical consequence metrics used in the analysis are reasonable proxy measures for likely third-party losses and cleanup and response costs.

The final component of the methodology involves the comparison of two designs.

By subjecting each design to the same set of accident scenarios, one can directly compare the resulting performance of the designs for each scenario. Since the relative impact on the environment can be assessed for each design, the better-performing design is evident for each accident scenario. All this is also very good.

But then the committee study in the report went a little wrong. The committee prepared two examples to demonstrate the application of the methodology and perform an initial test of its validity. Both examples involved comparing the performance of a double-hull design (with many small cargo tanks) with that of a conventional single-hull design (sic) with a normal number of cargo tanks - but maybe not optimally located ballast tanks! One example used vessels with a 150 000-deadweight ton (DWT) capacity and the other vessels with a 40 000-DWT capacity design. The apparent reason for this was that none of the alternative designs proposed to USCG was available to the committee in sufficient detail (sic) to be used in the examples.

Why the IMO mandatory design - mid-deck - and the only IMO approved alternative - COULOMBI EGG - was not used is unclear. Nobody asked Heiwa Co to provide the details. Why use a conventional single hull design, that is phased out, for the demonstration? The COULOMBI EGG tanker is also single hull - it is damaged exactly as a conventional single hull tanker - the only difference is that no oil spills!

The committee selected four case study locations in U.S. waters: Big Stone Anchorage (Delaware Bay), Galveston lightering area (Gulf of Mexico), Carquinez Strait Bridge (San Francisco Bay), and Farallon Islands (Offshore San Francisco). These locations have large volumes of tanker traffic, and adequate oil spill modelling data are available for each. These four locations also demonstrate sufficient variation in site characteristics and conditions to provide an adequate test of the components of the methodology. The committee ran a total of 80 000 accident scenarios (10 000 collision and 10 000 grounding events) for each of two designs (conventional single-hull and double-hull) of the two different sizes (150 000 and 40 000 DWT).

To determine environmental consequences for these events, the committee conducted a separate analysis and generated a set of consequence functions for the necessary range of oil outflows, also considering such factors as weather, oil types, and geography for the selected locations. With four sites, 200 weather events, two oil types (crude and product), and seven spill volumes, a total of 11 200 spills was simulated in the models used. The seven spill volumes were chosen to represent the full range of possibilities.

The consequence functions selected by the committee represent ratios of the environmental consequence for a spill of a certain size to that for a 500 000-gallon reference spill. The consequence function is not linear. That is, for spills smaller than the reference spill size, the consequence for each gallon spilled is relatively greater than for the reference size, and that difference continues to increase as the spill size decreases.

The opposite is true for larger spills. For example, for a spill of 100 times the reference size (a spill of 50 million gallons) the environmental consequence function would be only about 8 times greater. To test the validity of this result, the committee also conducted several sensitivity analyses--for different oil types, different case study sites, and different consequence metrics. These analyses provide upper and lower bounds for the consequence function graph and can be used to make the final design comparisons more accurate and complete.

Each of the 80 000 outflows was converted to a consequence measure, relative to the 500 000-gallon spill equivalent. By calculating and analysing the differences in this measure across the scenarios, one can determine the relative performance of two designs. However, this is not meant to be predictive of environmental consequences for any specific spill.

The double hull tankers (with many small cargo tanks) evidently spillt less oil in fewer spills and caused much less (20 times!) total damages in economical terms (in U.S. waters) than the conventional single hull tanker (to be phased out). Small spills evidently cost less to mop up than big spill, but small spill scost more per gallon to mop up than big spills.

It would have been very interesting to know the result of a comparison double hull versus an IMO approved, alternative design, i.e. mid-deck or COULOMBI EGG. The two latter perform much better in collisions and it would have been interesting to know the savings in money terms. In groundings the two alternative designs rely on hydrostatic loading to reduce spill volumes and the USCG has suggested that it is not good enough - due to the U.S. Clean Waters act (sic)! But the Clean Waters Act also apply to collisions! With the new methodology the real groundings costs can be estimated. Are the costs for many small spills due to hydrostatic loading of tankers higher compared with the rare grounding spills from double-hull? And if so - is the extra damage grounding costs for approved alternative designs in excess of the saved costs in collisions?

The study only involves U.S. cleaning-up operations - it would be interesting to know the relative costs to clean up spills in, e.g. Europe, Singapore and Japan, and it should be considered in an overall evaluation.

It is interesting to note that the cause of the latest, well-published spill had nothing to do with collision or grounding (or fire and explosion) - the 'Erika'. The proximate cause is still unknown - heavy weather, structural fault, faulty cargo loading? Who knows? But an alternative design that performs better in heavy weather and with more redundancy against structural faults and faulty cargo loading than double-hull should be credited. What will happen when the next 'Erika' accident occurs outside the U.S - with a double hull tanker?

Since the committee did not attempt to determine the likelihood of any of the scenarios actually occurring, the analysis cannot be used to determine the real savings that might accrue to use of a particular design in a given time period. The latter is a very different and more difficult problem that would require a detailed risk analysis of a specific port area with defined operations and traffic patterns. This is the type of analysis that would be required, for example, if one wanted to determine whether the additional costs of an alternative design were justified, the Committee concludes this part of the study.

The interesting thing is that COULOMBI EGG probably costs less than double hull to build - and maintain - no extra costs!

The committee developed a rationally based approach for assessing the performance of alternative tanker designs on the basis of their relative ability to prevent environmental damage from oil spills following collision and grounding accidents. This methodology can be used as a tool by regulatory authorities in determining whether to approve an alternative to the double-hull tanker design. This is extremely good.

First, however, a few other things need to be accomplished, the committee concludes: (1) peer review of the methodology; (2) testing of the methodology; and (3) a comprehensive review of the methodology by stakeholders, including the tanker industry and environmental groups, as well as regulatory, oversight, and review organizations. The methodology is a significant improvement over existing methods; however, it needs further refinement to enhance its accuracy and reliability.

This writer agrees fully (even if nothing seems to have been done since the report was issued and nobody ever informed the writer about developments). Even if the COULOMBI EGG tanker is already approved by the IMO, a new review according to the new methodology can only confirm that the COULOMBI EGG tanker is the superior design.

Based on its work, the committee makes the following recommendations, left, in the report with Heiwa Co comments right.

Recommendation 1: The USCG should use the proposed methodology for evaluating alternative tanker designs, and at the same time undertake a program to refine the methodology to address the issues discussed in this report.

Heiwa Co agrees fully.

Recommendation 2: The USCG should institute a standard procedure for evaluating specific designs submitted as equivalent to a double-hull design. This procedure should include the methodology proposed by the committee for assessing equivalency on the basis of environmental consequences from oil spills following collision and grounding accidents. Other appropriate factors, such as those associated with the safety and operation of the vessel, will have to be evaluated in conjunction with the use of this methodology.

Heiwa Co agrees fully with the following additional recommendations:
Safety and operation must be included in the methodology! Maintenance of double hull spaces is complicated and dangerous. Explosions are rare but oil spills due to explosions amount to similar volumes of collisions and groundings.
COULOMBI EGG protective spaces are evidently both safer and easier to maintain than double-hull.

Recommendation 3: To continue and validate the work of the committee, the USCG should apply the committee's methodology to compare other alternative designs with the double hull. The committee suggests that one alternative assessed be the mid-deck design, which is available in a detailed form and has already been evaluated by IMO.

Heiwa Co agrees fully with the following additional recommendations:
As the COULOMBI EGG tanker is already approved by the IMO, it should also be used by the USCG to validate the work of the committee. The committee is a bit illogical - to verify the methodology it used a conventional single hull tanker (sic) -see above - as the mid-deck design was not available in sufficient detail; here it is stated that the mid-deck design is available in a detailed form , etc. Regardless - only two other designs exist - mid-deck and the COULOMBI EGG. The USCG should evaluate both.

Recommendation 4: The USCG should define in sufficient detail and make available the standard reference ships needed for the methodology. This concept is similar in nature to the reference ships currently used by IMO. In developing the standard reference ships, the USCG should refer to the discussion of design of double-hull tank vessels in the 1998 NRC report entitled Double-Hull Tanker Legislation: An Assessment of the Oil Pollution Act of 1990.

Heiwa Co agrees fully. It does not actually matter what reference double hull ship is used. The COULOMBI EGG tanker spills so little oil in any accident, so it is more a question of the costs of the small spills expected. And why not evaluate the existing alternative designs at the same time?

Recommendation 5: Anyone proposing an alternative design should be required to submit to the USCG not only a complete description, including design plans, but also an analysis of the design and its performance within the framework of the models used in the proposed methodology, including such aspects as outflow under different accident scenarios. Sufficient information should also be provided to allow the USCG to perform an independent review of the proposed design. In addition, the USCG should prepare specific instructions for those who wish to submit alternative designs, including a list of required design plans, structural and mechanical details, and relevant calculations. The format and organization of a submission should also be specified.

Heiwa Co agrees fully as long as the COULOMBI EGG tanker is included in the validation process of Recommendation 3. It is then very probable that no other alternative design will ever be submitted to the USCG for approval! No alternative design has been proposed to the IMO until 2002 except the COULOMBI EGG since it was possible starting 1995. No government authority will evidently propose an alternative design. Only innovative individuals with maybe a support of a company may propose an alternative design and these should be supported by the public and, e.g. the USCG.

Nevertheless, if a design is proposed to the USCG it must evidently also be approved by the IMO, so the USCG should fully cooperate with the IMO when approving any other, new alternative designs (if any).

It is interesting to note that the USCG or the committee never interviewed Heiwa Co about the difficulties or ease to have an alternative design approved by, in this case, the IMO.

Recommendation 6: Any submittal to the USCG of an alternative design that includes an active system should include a quantitative life-cycle risk analysis, along with supporting information, so that independent verification can be accomplished by either the USCG or others. In addition, the USCG should develop the capability to review and evaluate all of the risk assessment factors that might be presented in such a submittal.

Heiwa Co agrees fully as long as the active measure is also approved by the IMO.

The only realistic active measure is evidently the transfer of cargo oil from a breached cargo tank to an un-damaged ballast tank. This is permitted by Marpol I since 30 years. The COULOMBI EGG active measure is magic!

Recommendation 7: The USCG should undertake a program to collect collision and grounding data in sufficient detail for use in validating both collision and grounding analyses. The USCG accident investigation report should routinely include data of the detail and extent necessary for this purpose. The data should be stored in a format that is easily accessible and conveniently usable by researchers. The USCG should encourage others, through IMO, to collect detailed accident investigation data in a uniform manner. In addition, the USCG should initiate a program for the continued development of grounding and collision analyses. The following areas need the most development:
*Addition of other than powered grounding on a single pinnacle
* Addition of collision with solid objects
* Addition of a deformable bow in the collision model
* Further development of the collision model at the structural member level .
As more data become available, the USCG should maintain a continuing program of testing and validation of the collision and grounding analysis tools.
(As discussed earlier, the consequence analysis performed by the committee indicated that the relationship between spill size and environmental consequence is not linear. In other words, the impact of spills increases with volume, but the marginal impact of each gallon spilled decreases. Thus the evaluation of an alternative design based on outflow alone would not be valid and could yield a misleading result. This conclusion led the committee to select an approach that could relate measures of environmental damage to each oil spill scenario.
Moreover, as explained above, the committee chose to use physical consequences, instead of historical spill costs, as the most consistently measurable and comparable method of evaluating environmental consequences).

Heiwa Co agrees fully as long as the COULOMBI EGG tanker is included in the validation process of Recommendation 3.

But let's face it! We know from long experience that collision tanker damage is more frequent in the area above the waterline only and that is why the collision protection must be maximized above and in the waterline. The weakness of the double-hull design is the uniform double side - it should be wider above waterline and could be single hull at the bilge.

The only controversy between the U.S. and the IMO is the assessment of single bottom/hydrostatic loading as grounding protection versus double bottom. Single bottom in combination with hydrostatic loading evidently increases the probability for very small spills due to 'initial exchange losses' but eliminates the risk of a large grounding spill. The IMO believes that a fair balance has been achieved by requiring any alternative designs to have much better collision protection . The new methodology can easily resolve this only problem.

The COULOMBI EGG design allows the 'initial exchange losses' in grounding to be eliminated by permitting the cargo oil to be pushed up in expansion trunks inside the tanker in lieu of spilling out through the breached bottom due to dynamic retardation effects. It would be interesting to hear what the committee and the USCG think about it. The IMO did not consider it, when approving the COULOMBI EGG, i.e. the probability of zero spill was 0 for the tankbody in all groundings, while it in reality probably is much higher - 70% of the groundings occur at speed <8 knots, most bottom damages are structurally small and you wonder if there are any 'initial exchange losses' then. 'Initial exchange losses' may only occur at speeds above, say 12 knots, in combination with large bottom damages and then the COULOMBI EGG tanker (and the mid-deck design) achieves >0.7 probability of no spill in groundings - more or less similar to double hull!

Recommendation 8: The committee recommends that the USCG take the committee's findings on evaluating environmental consequences of spills into account in its regulatory initiatives relative to environmental impacts of oil spills, including cost­benefit analyses.

Heiwa Co agrees fully as long as the COULOMBI EGG tanker is included in the validation process of Recommendation 3.

In addition the loss of human life in collision's should be included as on average 40 seamen die every year in tanker collisions due to fires starting after the collision.

Recommendation 9: The committee recommends that the USCG propose to IMO that it replace its current guidelines with a rational methodology for evaluating alternative tanker designs based on the principles presented in this report.

Heiwa Co agrees fully as long as the COULOMBI EGG tanker is included in the validation process of Recommendation 3.

The objective must of course be that Marpol I/13F and OPA90 have exactly the same design and approval rules and criteria . The USCG could then advise the IMO that the U.S. will adopt Marpol I/13F as a result of the proposal.

The committee understands that to implement all of its recommendations will require substantial time and effort on the part of the USCG, but has neither estimated the cost involved nor determined whether the USCG has the necessary resources available.
Therefore, the committee cannot propose an appropriate schedule for the recommended tasks, nor can it set priorities for this work relative to the USCG's other responsibilities.
The committee does, however, believe that the work presented to illustrate the proposed methodology provides a foundation that can be used by the USCG in its implementation efforts.  

The COULOMBI EGG is fully approved under Marpol I/13F and its current guidelines and will naturally continue to excel using any other guidelines or methodologies. The reason is simple - the COULOMBI EGG was developed 1989-1995 based on the thinking of the TRB committee 1999-2001. It is sad that the committee does not make any reference to this well documented work in its report. And it is time that the USCG seriously studies the COULOMBI EGG tanker - all the relevant information for approval is available since 1995. The USCG work should evidently start with the only alternative design approved by the IMO - the COULOMBI EGG tanker.

The COULOMBI EGG tanker can and will always fulfill any USCG requirements!

The COULOMBI EGG tanker can and will always fulfill the USCG requirements, if the methodology in TRB Special Report 259 is followed! How can Heiwa Co be so certain with such a statement?

The reasons are as follows:

1. The COULOMBI EGG tanker collision protection is always superior to double hull. It is a proven fact that about 50% of all serious collision damage is only located above the waterline (in less than 20% of the total side) and therefore the maximum protection should be located there and the cargo tanks should be as far away from the upper deck side/corner as possible. The reason why collision damage is concentrated above waterline is that most collisions are non-perpendicular and then the flare of the other ship slices off the upper deck corner structure. In more perpendicular collisions the unique Coulombi Egg side mid-deck with a sloping side to a cofferdam acts as an internal structural fender to protect the large centre cargo tanks. Only small lower side cargo tanks are exposed in the lower side where localized damage is extremely rare (1/1000 the probability compared with the upper side). Uniform double hull side (2 meters) is sub-optimal protection!

2. The COULOMBI EGG tanker grounding protection as per the IMO is evidently 100% single bottom + hydrostatic loading. Probability of zero outflow is by (rule) definition 0 in the tankbody, which by (rule) definition results in many small spills. The logic behind it was (based on the assumption that the rules were correct) that it was much easier to clean up a small spill with existing technology, etc. But also these very small spills - now when we know the cost - can be reduced! How? Evidently by increasing the probability of zero outlow! Assuming that the forwardmost bottom cargo tanks are most at risk you can, e.g. fit a very shallow - not regular depth - double bottom only in the no. 1 forward tanks (a cofferdam - not used for ballast - an extension of the double bottom in the fore peak). It is very good to know that 70% of all groundings occurs at a speed <8 knots (see figure 3.2 in the TRB report), which probably means that the grounding damage will in those instances be limited in the forward part of the bottom (20 or 25% of the tankbody) with limited vertical penetration. In 23% of the groundings the speed >15,5 knots and then you probably rip open the whole bottom, and then, and only then, may a full length double bottom be effective. The COULOMBI EGG collision logic is thus applicable also to groundings - put the protection - if it need be a double plate structure - only in the most exposed, high risk area - and leave the rest of the bottom single barrier + hydrostatic loading. The USCG approved COULOMBI EGG tanker may very well have improved grounding protection, say 20% of the tankbody forward, ensuring 100% probability of no outflow in, say maybe 50% of all groundings - the USCG risk and cost analysis will decide (this logic was explained to the IMO already 1995, when the COULOMBI EGG tanker was approved - if the Environmental index E for any reason was <1 for a COULOMBI EGG particular yard design, E>1 could easily be achieved by a partial double bottom forward. It could also be achieved by full depth side tanks forward, etc. in the curved parts of the tanker hull).


Put the oil outflow protection - steel structure - only where it is most required as per damage statistics to ensure 100% probability of no outflow. Locate cargo above waterline as far away from the sides as possible with as much horizontal steel as possible in between. Use hydrostatic oil outflow protection for cargo below waterline. Avoid double hull structure as far as possible everywhere. Do not permit any or minimum water inflow into the hull in groundings, but permit water inflow in collisions, so that the tanker heels against the colliding ship.

Use the COULOMBI EGG tanker design for optimum protection and safety

Uniform double hull structure in the whole tankbody is evidently not the optimal solution - too much double hull is located in areas, where no local damage will ever take place. And double hull spaces are inherent unsafe due to the risks of internal leaks, etc. (25 January 2002).


Heiwa Co invites students at U.S. universities and other interested parties to apply the committee's methodology to compare the COULOMBI EGG tanker design with the double hull. The relevant computer programs are available in the U.S. and the application could be used as a graduation thesis or part of a research program. USCG should support such work. Heiwa Co looks forward to the day the USCG approves the COULOMBI EGG and reports it to Congress and the Secretary of Transportation. The U.S. deserve the best tanker design - the COULOMBI EGG !

In spite of above, 2016, USA still do not accept the Coulombi Egg tanker. The reason is very simple. Just ask me and I will tell you.