Use of Cryogenic Buoyancy Systems for Controlled Removal of Heavy Objects From the Seabed

New methods for marine salvage and decommissioning of structures in the open sea are continually being sought in order to improve control and lower operational costs. This paper investigates the concept design of a lightweight cryogenic marine heavy lift buoyancy system. The objective is to be able to lift or lower large displacement objects under full remote control. The opening stages of the project work include the development of a system that will operate to a depth of 350m. As part of the design process for such an arrangement, numerical simulation of the complete system has been undertaken in order to develop mechanical, cryogenic and process control systems. The paper considers the overall design concept and associated system development issues. These are illustrated through use of the time accurate simulation of alternative design configurations that confirm their viability.