Liquefied gas carriers with membrane tanks
|Publication Date:||1 July 2017|
This class guideline describes procedures for strength assessment of liquefied gas carriers with membrane tanks in compliance with the rules DNVGL-RU-SHIP Pt.5 Ch.7. In case of discrepancy between the rules DNVGL-RU-SHIP Pt.5 Ch.7 and this class guideline, the rules shall prevail.
In general liquefied gas carriers with membrane tanks shall satisfy the strength criteria to main class as given in DNVGL-RU-SHIP Pt.3 of the rules. In addition, the criteria for classification notation Tanker for liquefied gas as given in DNVGL-RU-SHIP Pt.5 Ch.7 apply for the inner hull acting as support for the cargo tank insulation and the membranes. An overview of the ultimate limit state (ULS) and fatigue limit state (FLS) assessment is shown in Figure 1.
US coast guard requirement
Requirements given by the USCG, see Sec.9 , need to be considered for LNG vessels trading to US ports or operating under US flag.