The Korean Register said it has developed new class rules that completely revise the existing structural rules for membrane-type LNG carriers.
The new class rules apply the concept of equivalent design wave (EDW) based on direct load analysis.
This is to determine structural arrangements and scantling that meet the structural strength, buckling and fatigue strength criteria for various load scenarios, and re-verify it by applying direct structural analysis, KR said.
The new rules for LNG carriers cover membrane-type LNG ships over 150 meters in length
But the rules do not include only the conventional-sized LNG carriers but also the world’s biggest Q-Max vessels with a capacity up to 266,000 cbm.
Additionally, the classification society developed the new rules to fully comply with the international gas carrier (IGC) code.
Collaboration with shipbuilding giants
In order to test and improve the rules, KR has conducted an impact analysis on an LNG carrier working in collaboration with shipbuilders HHI, DSME, and SHI.
As a result of verifying the rules for the latest design of 170,000 cbm class membrane-type LNG ship, each shipyard also evaluated the rules as “highly competitive” in terms of structural safety and optimized design, KR said.
Furthermore, KR expects that the structural design time for LNG carriers will be “drastically shortened” through the inclusion of the new rules in its structural scantling and strength evaluation program ‘SeaTrust-HullScan’, which is already widely used by many design companies and shipyards.
In addition, KR has completed design approval for various types of cargo holds. These include GTT’s MARK Ⅲ and No.96, KC LNG’s KC-1, DSME’s SOLIDUS, and SHI’s SCA.
KC also provides technical services for Type B LNG carriers and Type C LNG bunkering vessels as well as for the membrane-type cargo holds.