Experts Puzzled Over Loss In ‘Relatively Calm Seas’

Theories abound over the cause of the ‘MOL Comfort’ disaster, but all experts agree that answers must be found — and soon.

Boxship experts are unwilling to speculate about the causes of the catastrophic failure of the 8,110-teu MOL Comfort (built 2008) — but they accept it is worrying that a modern ship that has recently passed its first survey should succumb to weather conditions it was designed to withstand.

They agree the most likely explanation will be a combination of factors, which could include design problems, construction faults and operational issues, whether to do with the loading of containers or driving the ship too hard through extreme weather.

Lloyd’s Register marine director Tom Boardley said: “This incident is of great concern, and we want to know why this happened.

“Fortunately, no crew were lost. Right now we can’t know what caused this structural failure. The causation will lie either in design, construction or operational factors — or a combination of these.”

Another class insider told Trade-Winds: “These kinds of things should not happen in relatively calm seas. These vessels have to be built to cope with the weather in the North Atlantic for 25 years.”

Little will be known until ClassNK, which classified the MOL Comfort, is able to investigate the loss. But it is possible that some similar factors could emerge, as they did in the report into the 2007 break up of the 4,700-teu MSC Napoli (built 1991).

Among the conclusions of the UK’s report into that accident, which may be relevant to the MOL Comfort loss, were claims that discrepancies in the declared weights of containers contributed to reducing the safety margin between the bending moment and strength of the hull, and that the wave loading was increased by whipping, which had an effect on the ship’s structure that could not be predicted with confidence by classification societies. It was also said that a reduction in speed could have reduced the risk of hull failure.

The MSC Napoli also suffered buckling issues around its engine room and fatigue cracking, and weakness of welds and longitudinal members related to its design and repair after an earlier grounding, which should not apply to the MOL Comfort, although steel fatigue will certainly be investigated.

The effects of wave length and period, which can cause the repeated flexing of a vessel’s hull, known as hogging and sagging, are well known to cause extreme stresses that can be exacerbated by poorly distributed or overweight containers, and a ship’s speed through heavy weather.

But experience of these effects over a period of time on the size and design of post panamax containerships is relatively limited.

As one class insider said: “All the societies will [be] looking through their books to see if they have similar vessels and to analyse whether there is a remote chance they might be exposed.”

The two sections of the MOL Comfort were still afloat as TradeWinds went to press, although tugs had not reached them.

“If the hull sections can be recovered safely, it will help those investigating [to] understand the causes, and more quickly, as well as substantially reducing the loss of cargo, so limiting insurance claims,” said Boardley.

For more maritime news see Tradewinds

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