Midship section

Container Ship

Purpose of Torsion Box in a container ship:

       Problems may arise in these vessels due to the lack of torsional strength caused by the large hatches.

       This problem is overcome to some extent by fitting torsion boxes on each side of the ship.

       These boxes are formed by the upper deck, top part of the longitudinal bulkhead, sheer strake and upper platform, all of which are of thick material.

       The boxes are supported inside by transverses and wash bulkheads in addition to the longitudinal framing.

       These boxes are only effective if they are efficiently tied at their ends.

       At the after end they extend into the engine room and are tied to deep transverse webs.

       Similarly at the fore end, they are carried as far forward as the form of the ship will allow and are welded to transverse webs.

       The longitudinal bulkheads below the box may have to be stepped inboard to suit the shape of the ship, the main longitudinal bulkhead being scarphed into the stepped section.