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.