Built in 1999 by Hanjin Heavy Industries Co Ltd, Korea, LNG tanker HANJIN MUSCAT has four cargo tanks contained in a complete double-hull structure, which includes ship sides and bottom, transverse bulkheads and upper deck trunk. This double structure not only protects the tanks from external damage, but also insulates the outer hull against critical steelwork fractures caused by the low temperature (-163°C) at which cargoes are carried.
The cargo containment system is a No 96-2 design from Gaz Transport & Technigaz (GTT). The insulation is formed by primary and secondary membranes of 0.70mm Invar sheets (a product containing 36% nickel steel) in conjunction with expanded Perlite beads contained in plywood boxes which are attached to the inner hull by stud bolts. This combination is able to sustain the liquid pressure and static and dynamic loads, and to limit the daily boil-off rate to 0.15% of cargo volume.