LR and GTT conducted a joint research and innovation programme investigating cargo containment behaviour, looking at strength aspects in various applications, sizes and at different pressures. The close collaboration between Lloyd’s Register and GTT experts, through workshops using experimental and analytical results and data on internal pressures occurring in LNG tanks, studied the maximum compressive strength of the containment system on LNG carriers. In October 2015, LR issued AiP for a GTT Membrane system with an increase in vapour pressure up to 2 barg for use in bunker ships to withstand the boil-off gas generated.
The project required a clear engineering understanding to maintain safety and reliability levels when implementation of membrane containment systems goes beyond atmospheric pressure applications.
Dariusz Boryszewski, Senior Specialist, Ship Structures, LR said: “This study carried out by our specialists and GTT’s was an effective marriage of our organization’s’ capabilities. Getting to Approval in Principle with the novel idea of pressurised membrane tanks is a real achievement”.
David Colson, Commercial Vice-President of GTT commented: “Thanks to our extensive knowledge and experience, GTT, together with Lloyd’s Register, has been able to demonstrate the feasibility of operating membrane tanks at higher pressures. This is a significant step in increasing the use of membrane tanks in the LNG as fuel chain for fuel tanks and bunker vessels.”
Source : Lloyd’s Register