The Coulombi Egg Oil Tanker - Secret 
Better protection, safer and more economical than Double Hull


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The secret
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General arrangement and structure
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COULOMBI EGG oil tanker - the Secret


With due respect for Double Hull, it is NOT the best protection for VLCC and Suezmax crude oil tankers, which need the best collision protection and the safest arrangement and the most reliable structure with plenty of redundancy against fractures and corrosion. Double Hull structure lacks redundancy. There will be more 'Prestige'-type structural failures and oil spills due to Double Hull than ever before with Single Hull.

The COULOMBI EGG oil tanker puts all the segregated ballast in Top Side Tanks in the cargo tank body, which become a collision crush zone, where collision damage actually takes place. No double hull - keep it simple!

The risk to breach a cargo oil centre tank above waterline followed by FIRE in collision is reduced considerably as the crush zone is much wider than Double Hull.

The explosion risk in the ballast space is also reduced as the COULOMBI EGG ballast spaces are much easier to ventilate and access than a Double Hull.

The amount of structure to protect against corrosion in the ballast spaces is reduced three times. The Coulombi Egg tanker structure - the side shell transverse webs supported by a mid-height deck - is very robust. And surprisingly the grounding protection is improved by top side tanks as cargo may be pushed up here in a grounding (under controlled conditions) to e.g. prevent further spill due to tide.

About 40-50 seamen lose their lives every year in tanker collision and explosion accidents. Even if most of these accidents occur on conventional single hull tankers it is thought that Double Hull will not reduce these accidents, as the particular risks behind these accidents (severe collisions and oil leaks into ballast spaces) were not properly addressed when Double Hull was mandated for large crude oil carriers. The COULOMBI EGG arrangement on the other hand was developed based on accident statistics and an attempt was done to eliminate those risks that cause loss of life (and not only oil pollution) in accidents. It is thus easy to demonstrate that the COULOMBI EGG provides better safety for seamen than Double Hull, even if this aspect has never been properly addressed by the IMO after Double Hull and alternative designs were mandated from 1 July 1993.

The COULOMBI EGG is the one and only alternative oil tanker design approved by the IMO as per Marpol I/13F(5) since 1993! It is unlikely that there is a better and safer design, as the COULOMBI EGG spills virtually nil oil in all accidents (and much less than Double Hull). Actually no better design has been suggested to the IMO 1997-2002.

The designer is thus amazed of the fact that the IMO does not mandate COULOMBI EGG as the basic norm for (large) oil tanker design and that no COULOMBI EGG has never been built since 1993. Maybe it is the ultimate secret of the COULOMBI EGG. It is too good to be true. And of course, the COULOMBI EGG tanker is banned from US waters in spite of hard lobbying for many years.