MOL Comfort probe can't simulate what happened - 'We still don't know'

THE ClassNK investigation in the splitting to two and sinking of the 8,110-TEU MOL Comfort in the Indian Ocean little more than a year ago has been unable to carry out simulations of the accident with any predictability.

"We still don't know what went wrong," said ClasNK executive vice-president Yasushi Nakamura conducting the probe.

The probe uncovered several possible reasons why the incident occurred, but failed to prove any of the possible scenarios when it ran simulations based on available data.

Before the splitting of the ship, seamen found buckling deformation of 20 to 40 millimetres under No 5 hold, which investigators said was not repaired. No similar deformations were recorded in regular classification society surveys.

But taking the data into the computer model, the investigators found the load the ship carried was still below hull strength, reported Lloyd's List.

Some speculate that since the series of ships is among the first to adopt high-tensile-strength steel which might be a factor in the casualty. But ClassNK says there is no evidence for that because the steel is used around the hatches and not the hull's bottom plates.

"This suggests that the ship should not have split and that buckling deformation did not occur on vessels of similar design during simulations even when applying loads near full hull strength," said Lloyd's List.

MOL sues shipbuilder Mitsubishi for splitting of MOL Comfort's hull

MITSUI OSK Lines (MOL) is suing Mitsubishi Heavy Industries for US$132 million because of alleged defects in building 8,110-TEU MOL Comfort that split in two and sank in Indian Ocean little more than a year ago.

"The double-bottom structure contained defects in design, rendering it incapable of enduring the foreseeable working loads a vessel of this size and type should be capable of safely withstanding," said MOL lawyers from Yoshida & Partners.

"The defects should have been foreseeable and avoidable at the design and construction stage. It was strongly suspected that this breach was caused by insufficient buckling strength of the double-bottom hull," they said. 

The ship was carrying 4,372 boxes at the time of the sinking, all of which were lost overboard.

Subsequent inspection of the five sister ships found buckling deformation of about 20 millimetres at locations the shipping line said were "close" to where the MOL Comfort began to split.

Although it made no conclusions, an investigation committee formed by Japan's Ministry of Land, Infrastructure, Transport and Tourism said in an interim report that the breach could have resulted from excessive work load or deformation of bottom shell plating.

MOL said there was a lack of evidence to suggest an excessive load, which would have heightened risk in extreme weather or uneven distribution of container weight.

"The uneven distribution of cargo weight would not be so significant in practice that it would be capable of causing a breach of the vessel's bottom hull structure," said the lawyers' brief.