Tuesday, 18 June 2013

MV MOL Comfort Present scenario and cause analysis report by Naval Architects.......

MV MOL Comfort Present scenario(photos) and cause analysis report by Naval Architects....... 

EARLIER: MOL COMFORT SUFFERS BROKEN BACK, SINKS OFF YEMEN

26 crewmembers of an MOL containership were forced to abandon ship Monday off Yemen after the ship suffered from catastrophic hull failure and reportedly sank.


The MV MOL Comfort, an 8,000 TEU-type containership cracked in half about 200 miles from the Yemeni coast at about 12’30″N 60′E while enroute from Singapore to Jeddah with a load of 7,041 TEUs. All 26 crew – made up 11 Russians, 1 Ukrainian and 14 Filipino

The MRCC in Mumbai has just tweeted saying that the sections of MOL COMFORT are still afloat and are being monitored.


         
            According to a report by IANS News, the Indian Coast Guard in Mumbai diverted three vessels in the area to assist. The MV Yantian Express was first to arrive on scene and rescued the survivors.  The 2008-built MOL Comfort sank a short time later, the report said.

Weather at the time was strong winds and seas up to six meters.

            The ship’s operator, Mitsui O.S.K. Lines, says that an Emergency Control Headquarters has been established for the incident and MOL is taking company-wide measures to settle the matter. The MOL statement said that damage was “extensive” and that details of the incident were still being confirmed.





A Catastrophic Structural Failure
                From a naval architecture standpoint, this is a puzzling situation.  Ships are designed to handle long period and large waves that crest on the bow and stern and have a trough amidships.  This creates a sagging situation that puts extreme tension on the keel and compression at deck level.  The opposite, “hogging” situation occurs when the crest of the wave moves to the center of the ship and the trough of the waves are at bow and stern.

The repeat flexing of the ship in these perfectly timed waves is likely what caused the loss of this vessel.  In the photo above, a perfect example of hogging is shown, where the bow and the stern are both lying in the troughs of two waves.

It should not have happened however.  Ships are built to handle this situation and engineering rules are followed to ensure the transverse “section modulus” of the vessel is sufficient to handle these extreme stresses imposed by nature.  There are other possibilities however…


The loading of the containers on board may have exacerbated the situation.  Although the loading of the containers appears even in the photo, the weight distribution of the containers may not have been even.  Had heavier containers been loaded on the bow and stern and lighter ones in the center of the ship, the vessel may have been placed in a hogging situation before she even set sail.  It’s speculation of course to say one way or another, but assuming that she met class requirements, it’s one possible explanation for what happened.