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Encyclopedia of Marine and Energy Technology

Semi-refrigerated gas carrier NORGAS ORINDA


According to The Motor Ship December 2002 and Significant Ships of 2002

Delivered by Hudong-Zhonghua Shipyard in 2002, the NORGAS ORINDA is the innovative and highly efficient gas carrier. Within a double-skin hull, there are only two cargo tanks, as opposed to the more common arrangement of four to six tanks found on similar ships. Their cylindrical shape with spherical ends offering 30% less surface are than bi-lobe design. Sub-supplier of the gas plant, Tractebel Gas Engineering developed an installation in which IMO tank pressure has been increased from 4.5bar to 7bar and, together with the maximum cooling capacity, quoted as 2°C/day in tropical waters, loading time for ambient propylene at 25°C has been cut by two/three days, whilst between 4 and 10 days can be saved when cooling a cargo from 25°C to -46°C.

A cylindrical 90m3 cryogenic tank is installed on the upper deck for the carriage of coolant, with a vaporising system enabling a quick “gassing-up” process. The super cooling facilities allow the ship to carry fully-refrigerated ethylene at –104°C, which is the most significant cargo followed by LPG and other gases such as propylene, propane, butane and ammonia. Cargo processing equipment is automated, and controlled from the bridge, along with ballasting and operation of the main engine.

NORGAS ORINDA is fitted with a main engine, developing 6300kW and driving a highlyskewed four-bladed CP propeller through a Renk gearbox which has a power take-off for a 1700kW alternator. The arrangement is designed to operate in reverse – as a power takein to provide propulsion in an emergency. Additional electrical supply is derived from four D2824 LE diesels each linked, to a 600kW generator.

With the emphasis on fast port turnarounds, the vessel is provided with the high-efficiency flap rudder and a 700kW CPP bow thruster. This enables the vessel to track sideways and turn within its own length. Additionally, the vessel is fitted with an efficient and quick mooring system.

Length, oa: 124.90m, Length, bp: 115.00m, Breadth, mld: 19.80m, Depth to main deck: 11.50m, Draught design/scantling: 6.70/8.30m, Lightweight: 4900t, Deadweight design/scantling: 6000/9400dwt, Service speed at 85%MCR: 16.7 knots, Total cargo tank volume: 8 550m3 .

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