Great Ships of 2014: Gas Star - 84,000 CBM LPG Carrier
Gas Star is the first of two 84,000 CBM LPG Carrier built by Hyundai Heavy Industries for KSS. The vessel measures 225 x 36.6 m, with a depth of 22.2 m and a design draft of 11.6 m.
The ship is powered by a HYUNDAI-MAN B&W 6S60MC-C8.2 main engine with a NCR output of 11,340 kW at 89.5 rpm, enabling it to sail at a service speed of 16.8 knots with 15% sea margin. Electrical supply is derived from three generators of 1,140 kW, plus an emergency unit of 150 kW.
It has a cargo space divided into four cargo holds. Each hold accommodates a free-standing and saddle supported prismatic cargo tank, designed for a maximum vapor pressure of 0.275 bars g and a lowest operating temperature -50 degrees C. Cargo tanks are insulated with 120 mm thick sprayed polyurethane foam with 1-3 mm polymeric coating. Fuel oil tanks are constructed in double hull structure to protect the fuel oil tanks from external damages.
It is designed for simultaneous loading, transport and discharging of two grades of cargo, both of which may be refrigerated, and it is capable of containing and handling commercial butane (ISO and normal), pure propane, commercial propane (max 5.0 mole % ethane in the liquid phase), mixture of propane and butane in any proportion and propylene. It is also capable of carrying other products, provided that their aggressiveness, pressure, temperature and specific gravity are within the limits of the design.
A reliquefaction plant of the carrier can simultaneously handle two grades of refrigerated cargo, and major equipments such as four oil free, three cylinders three stage cargo compressors and motors are located on main deck in enclosed deck house. One cargo heater (combined with vapourizer) and one inert gas generator are provided. Three 1,140 kW diesel generators, one auxiliary boiler (3,000 kg/h), one exhaust gas economizer (1,500 kg/h) for the main engine is provided. Cargo unloading is conducted by a pair of deepwell pumps per each cargo tank, each with a capacity of 600 cu. m./hr., allowing for discharge of a full cargo in about 19 hours. Loading a full cargo, at maximum rate of 4,800 cu. m./hr. from fully refrigerated atmospheric storage is accomplished in about 19 hours based on vapor return to shore.
(As published in the December 2014 edition of Maritime Reporter & Engineering News - http://magazines.marinelink.com/Magazines/MaritimeReporter)