KR Webzine Vol.135

America's growing shale gas exports and China's trend for eco-friendly energy consumption are two factors currently driving higher demand for Liquefied Natural Gas (LNG) carriers. According to Clarkson’s Research, ship building orders are expected to increase sharply for both LNG carriers and container ships as the world economy and logistics industry continue to grow. Demand for LNG carriers is particularly strong, with hundreds of orders expected in the next 10 years. Reflecting this, KR is developing the rule-based load which can be used to evaluate the structure of LNG carriers as a first step to developing the structural rules for membrane type LNG carriers.

Figure 1 Global LNG fleet by capacity and year of delivery

Rule-based loads uses the concept of design load scenarios and dynamic loads which are based on the Equivalent Design Wave (EDW) concept. The loads are developed for strength assessment and fatigue assessment depending on their application, each of which includes the load combination factor, ship motion and acceleration, hull girder loads and external pressure, etc. Such developed loads can be applied to all membrane type LNG carriers and will be included in the structural rules in the future.

Figure 2 Motion and statistical analysis results