The greatest problem occurs towards completion of loading or initial stages of discharging when the tanks are almost full and the ballast is almost empty with both ballast and cargo providing free surface effect and raising KG.
At these stages the concerned officers should take extreme care not to reach the angle of loll, especially when multiple tanks are loaded or discharged.
Other than the above designs may also be accepted by IMO provided that they offer equal amount of protection incase of a damage to the hull.
One such revolutionary design was the “ Coulombi” egg design created by the Swedish naval engineer Anders Bjokman.
It constituted a feasible and efficient alternative to the “double hull”, and in fact, won the approval of the IMO in September 1997, under MARPOL annexe 1-13 F.
However, the US government (U.S.G.C.) Maintained the supremacy of the “double hull”, pursuant to the OPA, and so the “Coulumbi egg” was reduced to the status of merely an interesting research project.
