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Encyclopedia of Marine and Energy Technology

Cargo handling equipment of a typical 138,000m3 LNG tanker


The ship has four membrane type cargo tanks. A tripod mast is built inside each tank with the filling line and two 1700 m3/h electric, submersible pumps attached. Complete discharge can be done within 12 hours, with loading handled by shore pumps after the tanks have been pre-cooled by a LNG spray. Vapour produced during these processes is returned to shore using two 32,000 m3/h compressors, a 26,000 kg/h main vaporiser and two heaters. Forced boil-off and delivery of gas fed to the propulsion system are achieved by two 8500 m3/h compressors and a 7600 kg/h forcing vaporiser combined with 540kW heater. Inerting of the insulated space and cargo tanks is accomplished by means of two 90 Nm3/h nitrogen generators and a 14,000 Nm3/h inert gas generator (IGG). Two 1250 m3/h vacuum pumps, four 50 m3/h stripping/spray pumps, and a 550 m3/h emergency cargo pump are also fitted.