ClassNK has released a second edition of its Guidelines for Liquefied Gas Carrier Structures (LGCs) – Independent Prismatic Tanks.
The Guidelines specify the technical requirements specifically related to the structural strength assessments of liquefied gas carriers by using direct calculation. The Guidelines take into account the complex interaction of loads between hull structures and cargo tanks, independent from the hull structures. Target structures to be assessed are independent cargo tank structures and their support structures, as well as the hull structures.
The Guidelines specify the design loads dominant for each structure, strength analysis methods and corrosion deductions, as well as the design scenarios in which assessments are required by the IMO’s IGC code. The Guidelines, therefore, cover all structural requirements for LGCs with independent prismatic tanks.
The Guidelines include components for Direct Strength Analysis, and for Fatigue Strength Assessment. The Second Edition contains covers the Guidelines for Fatigue Strength Assessment.
The Guidelines for Fatigue Strength Assessment outline strength assessment methods against fatigue cracks caused to vessels by prolonged and repeated loads. Implementing fatigue strength assessment methods that follow the guidelines, makes it possible to carry out more reasonable fatigue designs for primary members of hull structures and of independent cargo tank structures and their support structures.
The guidelines are available to download free of charge by clicking this link.
Images courtesy of ClassNK.