SAFETY EVALUATION OF MARK III TYPE LNG CARRIERS UNDER BARRIER LEAKAGES

摘要

Liquefied Natural Gas (LNG) carriers of MARK III type cargo containment system are widely used over the world since they provide more space to carry and lower fuel cost. Recently developed LNG fields around artic areas need more robust LNG vessels enough to be safe from vibrations and unexpected collisions against arctic ices. In this situation there have been concerned about cargo containment system in case of severe damages during voyage. Safety evaluation will be made for the MARK III type LNG carriers, in case both primary and secondary barriers are damaged from unexpected forces. The endurance of the MARK III system will be checked according to the international gas code standard using a commercial numerical code. In the calculation phase and temperature change of LNG at each part of the cargo system will be inspected with two and three dimensional models. A rather simplified model calculation might not be enough to confirm its validity. So if necessary, the test to confirm the numerical model may be planned under clearly defined procedure and environment for considerable time. Through theoretical and or experimental investigations will show if the MARK III type is safe even under extreme cases.