ABS revises criteria for LNG carriers with independent tanks

Type-A independent tanks were used on the first generation of LNG carriers and are now used for fully refrigerated LPG containment systems for vessels with capacities of up to 90,000 cum, of which several are currently on order. The Self-supporting Prismatic Type-B (SPB) independent tanks for LNG vessels are receiving new attention as the interest in floating LNG terminals and regasification units increases.  Type-B spherical tanks continue to be selected for LNG carriers and considered for new floating LNG units.  Type-C independent tanks used for fully pressurized LPG carriers and the new generation of small coastwise LNG carriers are also covered in the Guide.   

The newly revised ABS Guide provides a multi-level approach to the evaluation of the structure of a proposed design. This roadmap creates a structural evaluation hierarchy so that a practical, deterministic assessment of initial designs for these carriers can be made more quickly and easily.  Where required, increased design confidence also can be gained by applying more advanced structural analyses, including the dynamic loading approach (DLA) and spectral fatigue analysis (SFA).   

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