The double hull structure has popul

The double hull structure has popularly been applied to the bottom of cargo ships, and also to the newer types of ship such as container ships and LNG carriers. Furthermore, it has been recently regulated that for a large tanker the double hull structure has to be applied to the bottom and the side shell. The double hull structure of a cargo ship can prevent the water coming into the hold when the outer shell is wrecked by grounding and collision. For a container ship the double side hull structure is to be applied to maintain torsional strength which is reduced by the large hatch openings. A small container ship is designed with a single hull structure. These double hull compartments are used as ballast tanks.