Page 16: of Marine Technology Magazine (January 2006)

vessels

Complete twin-screw medium speed propulsion packages have been ordered from MAN B&W for a twin set of 65 m off- shore research vessels. The twins will each be specified and equipped for specific opera- tional tasks, i.e. seismic sourcing and seismic recording. The vessels are designated as an

OBC Source Vessel and an OBC (Ocean

Bottom Cable) Recorder Vessel, respectively.

The design consulting company for this project is Dalian Shipbuilding Technology

Research Center Co. Ltd., located in

Dalian, China. Both vessels will be built by

Liao Nan Shipyard, also located in Dalian, and the delivery of the first vessel is sched- uled to the end of 2006. The operator and owner is BGP/CNPC (China National

Petroleum Corporation) and its fleet is mainly based in Tanggu, Tianjin. The oper- ation areas for these two vessels include off- shore China and other overseas destinations.

MAN B&W Diesel's Four-stroke

Propulsion Sales Manager, Jorgen Vinde, said: "Very low levels of vibration and noise from propellers, engines and propulsion sys- tems are key issues for these installations. A very soft resilient seating arrangement of base frame and sandwich mountings has been applied for the dampening of struc- ture-borne vibrations by upwards of 97 per- cent. Additionally, the ducted propellers have been specially designed and shaped with high priority to low levels of cavitation and noise emission. From an underwater point of view, an absolute decisive factor for the customer is a very silent ship, with min- imal noise emission and disturbance in rela- tion to the seismic exploration equipment."

The MAN B&W Diesel twin-screw Alpha

Propulsion System type 6L23/30A-DVO, which has been specified for the newbuild- ings, includes: • Main Engines: Two MAN B&W 6L23/30A-D engines, resiliently seated with baseframe and sandwich mountings. Each develops 960 kW (1305 bhp) at 900 rpm. Reduction Gearboxes: Two MAN

B&W Alpha AMG8 gearboxes, type 31VO8, with a speed reduction ratio of 900:292. Propellers: Two MAN B&W Alpha type VB560 four-bladed controllable pitch propellers. The 1,900 mm diameter CPP systems are complete with tail shafts, inter- mediate shafts, bearings and stern tube equipment. Control System: In addition to the twin main bridge control station, the complete

Alphatronic IIA Propulsion Control and

Safety System includes a twin engine room control station.

Visit www.maritimeequipment.com/mt & Click No. 30

Main Particulars

Length, oa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65.0 m

Length, pp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58.4 m

Breadth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13.8 m

Depth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.1 m

Draft . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3.5 m

Crew 45

Propulsion . . . . . . . . . . . . . . . . . . . . . . . . .MAN B&W Diesel

Chinese Seismic Exploration

Require New OBC Vessels 16 MTR January 2006

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