Rocks & mirror

Encyclopedia of Marine and Energy Technology



Claimed to be the largest, purpose-built seismic vessel worldwide, the OCEANIC VEGA was delivered on 2nd July 2010 by Ulstein Verft. A powerful seismic research vessel with an overall length of 106.5m and moulded breadth of 28m, has a towing force of 140t during seismic operations and is designed to facilitate large 3D, 4D or high-resolution projects. The vessel can utilise a current streamer configuration of up to 16 streamers separated by 100m or more.

The vessel’s 20 streamer winches are each capable of spooling 9km of the 5 mile-long neutrally buoyant devices that contain the hydrophones that detect the energy reflected from the beneath the seafloor. The seismic instrument room is located far aft on the top deck overlooking the seismic area and providing a clear view of the streamer deck. The vessel is also equipped with a spread of streamer winches, towing points and gun winches. A storage area above the instrument room is served by a gantry crane with a 2x7.5t capacity. Two knuckle jib-type deck cranes with SWL 15t at 18m are placed amidships and serve the storage and provision rooms. Two large paravanes are launched and retrieved by two off shore cranes with operator cabins. Two seismic workboats will be used for maintenance of in-water equipment.

Propulsion is based on a diesel-electric confi guration with four 12-cylinder Wärtsilä 26 generator sets, each delivering 3745kWe at 900 rev/min, and two 6-cylinder Wärtsilä 26 gensets rated at 1870kWe are divided into two separate machinery rooms to provide the full redundancy. Two 3000kWe variable speed electric motors, working in tandem configuration, each drive a nozzled, 4200mm diameter CP propeller. This provides smooth speed control of around 5 knots during seismic acquisition, a maximum transit speed of 18.2 knots and a bollard pull of 190t.

One 1200kW CP bow tunnel thruster and a single 830kW CP stern thruster aft provides additional manoeuvrability. For improved comfort, the vessel is fitted with two roll reduction tanks.

Length oa: 106.5m, Length bp: 99.3m, Breadth: 24.0/28.0m, Depth to main deck: 10.0m, Draught design/scantling: 7.0m/8.0m, Deadweight max: 6013dwt, Accommodation: 70 people.

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