Vessel design blamed for MSC Napoli breakup

The design of the MSC Napoli, rather than its condition or structure, was to blame for the structural failure of the containership in the English Channel in January 2007, a British investigation has found.

The incident drew international attention when scavengers looted containers washed up on the Devon Coast.

The Marine Accident Investigation Branch (MAIB), an independent branch within the United Kingdom抯 Department for Transport (DfT), has recommended a review of the technical rules used in containership design and said at least 12 other ships of similar design could have the same flaw.

The 53,409-deadweight-ton MSC Napoli was built in 1991 by Samsung Heavy Industries in South Korea. It was deployed on Mediterranean Shipping Co.'s service between North Europe and South Africa via the Canary Islands on charter from Zodiac Maritime Agencies Ltd. The registered owner is Metvale Ltd.

Sailing at a speed of 11 knots, the 4,419-TEU vessel was on passage in the English Channel on Jan. 18, 2007 when it suffered a structural failure of the hull causing the engine room to flood. The ship was under tow towards Portland when the decision was made to intentionally ground it in Branscombe Bay due to a risk of sinking. The bow section was several months later taken to the Harland and Wolff shipyard in Belfast for disposal. Work to remove the remaining stern section will begin in early May.

The MAIB identified a number of factors which contributed to the failure of the hull structure, including:

   The vessel's hull did not have sufficient buckling strength in way of the engine room.

   The classification rules applicable at the time of the vessel's construction did not require buckling strength calculations to be undertaken beyond the vessel's amidships area.

   There was no, or insufficient, safety margin between the hull's design loading and its ultimate strength.

   The load on the hull was likely to have been increased by whipping effect.

   The ship's speed was not reduced sufficiently in the heavy seas.

   The MAIB requested classification societies to conduct urgent checks on the buckling strength of a number of ship designs. More than 1,500 ships were screened, of which 12 vessels have been identified as requiring remedial action; a further 10 vessels were identified as being borderline and require more detailed investigation; and the screening of eight containerships was still in progress at the time of publication.

Until such structural work can be completed, their safety will be ensured through operational limitations, said Stephen Meyer, MAIB chief inspector.

Source: Transportweekly