Buckling found on MOL Comfort sisterships

"During the inspections of the sister vessels, buckling type deformations measuring approximately 20mm in height were observed on the bottom shell plates in the vicinity of center line of midship area,” ClassNK said today.

It remains unclear whether the deformations on the sister vessels are signs of a weakness that led to the MOL Comfort’s sinking, but the ship’s sister vessels continue to undergo preventative structural reinforcements. The location of the deformities is also consistent with the belief that the failure began at the bottom of the ship, as indicated by the presence of water-ingress at bottom-midship at the start of the casualty.

The MOL Comfort had six sisterships; MOL Celebration, MOL Courage and MOL Creation have all completed their structural reinforcements, along with MOL Charisma and MOL Competence, but the youngest of the sisterships, MOL Commitment is not expected to be ready before February 2014.

ClassNK said shipowners are cooperating with the Japanese class society to investigate whether similar deformities are apparent on other large container ships of different designs.

ClassNK has recommended that crew on large container vessels check for signs of deformation on the bottom shell plates, and are offering free of charge inspections by surveyors if requested by a shipowner. The class society is recommending an occasional survey for any ship showing any consecutive deformations along its length.