French liquefied natural gas containment systems specialist, GTT has obtained approval in principle (AiP) for its Mark III Flex and NO96 L03+ systems designed for Arc7 ice-class ships from the Russian Maritime Register of Shipping (RS).
These containment systems, designed for Arc7 ice-class ships both offer a daily boil-off rate of 0.085 percent and 0.10 percent, respectively, GTt said in its statement.
RS and GTT analyzed the containment systems in terms of safety of operation aboard a ship navigating in ice-covered waters.
Under the AiP procedure, GTT and RS considered containment system strength under hull vibrations, as well as fatigue endurance of the containment system elements.
Additionally, containment system safety in case of possible interaction with floating ice or icebergs, and structural strength of the membrane systems under potential impacts (sloshing events) related to liquefied gas movements in the cargo tanks have been analyzed and validated.
In March 2019, GTT and RS signed a bilateral cooperation agreement covering experience exchange and membrane cargo containment systems installation aboard RS-classed ships. The agreement foresees communication during the development of technical requirements and additions to the RS rules as well as the approval of materials, products, technologies and GTT-designed LNG containment systems by the classification society.
Under the agreement, RS surveyors undertake a training course on the technical know-how of GTT LNG containment systems.