Structural analysis of a steel double hull underwater tank, intended for oil recovery from shipwrecks

In the present work, the survivability of a submerged structure against loads, imposed by the operational environment, such as hydrostatic pressure is presented. The structure under consideration is a component (buffer bell) of a system called DIFIS that recovers fuel from shipwrecks. It consists of two parts: the reservoir and the floater. The floater is the part that produces the buoyancy force that holds the whole system in place and therefore its structural integrity is crucial for the safety of the structure. The floater is designed as a double hull structure made of steel plates and stiffeners. The task of the structural analysis is to ensure that the floaters’ double hulls are able to withstand the hydrostatic pressure due to the depth and maintain the needed buoyancy forces. In the present analysis, the strength of the hulls is evaluated for three different scenarios (operational, worst case and accident scenarios).