A Rubber Bag for Liquid Cargo to Improve Ship Collision Resistance

Abstract

Collisions and grounding accidents of ships, but also the failure of the hull-integrity, can lead to oil leakage. Examples are the Rena in 2011, the Hebei Spirit in 2007, and the much known accident of the Prestige in 2002. Consequently, research regarding the enhancement of the structural design to increase the safety-level of ships in case of accidents is important. In this paper, the use of a rubber bag as a second barrier is presented as an alternative concept to prevent oil leakage in case of accidents. The influence of the rubber bag is investigated using the exemplary simulation of a ship collision. A simplified tanker side structure as well as a box-shaped rubber bag is analyzed with the finite element (FE) method. The material model for the rubber bag is calibrated with tensile tests to obtain the required material parameters. The reaction forces and the associated penetration depth are analyzed. The comparison is done between the structure with and without the rubber bag. For the latter, the general behavior of an empty tank in a ship side structure is compared with the large-scale experimental results. Furthermore, an additional increase of the collision resistance of the ship due to the rubber bag without changing the common structural design is discussed.