An innovative ship salvage concept and its effect on the hull structural response

Abstract

In the European research project ‘Surfacing System for Ship Recovery’ (SuSy), gas inflated balloons are envisaged to be used for providing reserve buoyancy to damaged ships for the purpose of preventing ship capsizing and/or sinking, along with lifting wreckages from the seabed. This paper presents the proof of concept tests of the prototype salvage units applied on a full-scale demonstrator section of a double bottom structure, together with measurements of its structural response. Two scenarios of internal and external deployment of the inflatable rescue units were examined. In both cases, the demonstrator was successfully salvaged. Data from the structural response of the demonstrator revealed certain operational aspects of the salvage system which directly affected the response of the salvaged structure. The monitored structural response of the demonstrator during operation of the salvage system was well within the elastic regime of its material (Grade A steel). Accordingly, finite element simulation of the salvage system supporting structure was conducted. The results of these simulations were found to be well correlated to the corresponding experimental measurements.