Ulstein delivers powerful X-Bow seismic research vessel

With a length of 106.5m, a beam of 28m and a design draught of 7m, the newbuilding is the first of two powerful seismic research vessel of the SX120 type designed by Ulstein Design & Solutions. With a towing force of 140 tonnes during seismic operations, the vessel is suited to undertake large 3D, 4D or high-resolution projects, using a current streamer configuration of up 16 streamers separated by 100m or more. The vessel’s 20 streamer winches are each capable of spooling 9 km of streamers.

Carrying an ICE-C classification, the 12,550gt Oceanic Vega is able to operate in cold waters. She is designed to stay permanently at sea, with five-year docking intervals and refuelling carried out by dedicated support vessels, and complies with the redundant propulsion notation from DNV. With six gensets, the vessel is able to carry out engine room maintenance at sea.

The Wärtsilä diesel electric power plant comprises four 12V26 gensets each of 3,745 kWe at 900 rpm and two 6L26 each of 1,870 kWe at 900 rpm. The vessel is equipped with straight shaft lines to the two 6,000kW, 4,200mm diameter CP propellers in nozzles with a speed of 40-135 rpm, each driven by two 3,000 kWe frequency converter-driven variable speed electric motors in tandem configuration. 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 190 tonnes.

Manoeuvrability is enhanced with the installation of a 1,200kW CP bow thruster and an 830kW CP stern thruster. For improved comfort, the vessel is fitted with two roll reduction tanks while the X-bow results in lower added resistance and smoother bow immergence which leads to reduced operational disruption and involuntary speed reduction.

Oceanic Vega complies with the Clean Design demands from DNV, and with the SPS (special purpose ship) requirements for up to 60 persons and a green passport complying with IMO ship recycling recommendations. Built with a hotel compliment with permanent capacity for 70 persons, there are 52 single cabins and nine double cabins while the public areas contain a mess room, galley and four dayrooms all of which have large windows facing the sea. The newbuilding is equipped with a 26.1m diameter, 14.7 tonnes helideck to facilitate an efficient crew change.

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. Special attention has been given to the design ensuring an ergonomic space for crew in the work place. A storage area above the instrument room is served by a gantry crane with a capacity of 2 x 7.5 tonnes. The two deck cranes, placed on C-deck mid-ship, have a capacity of 15 tonnes at 18m, and serve the storage and provision rooms. The large paravanes are launched and retrieved by two offshore rated cranes with operator cabins. Two seismic work boats will be used for maintenance of in-water equipment.

Ulstein Power & Control has delivered a substantial amount of equipment for the vessel, such as the information and communication system Ulstein COM, the navigation system Ulstein NAV, and the integrated automation system Ulstein IAS which is equipped with integrated modules, among them PMS (power management system) and monitoring of helideck.

Commenting on the latest vessel to join its fleet, Jan Fredrik Meling, CEO at Eidesvik Offshore, stated: “

Oceanic Vega

meets strict environmental standards. The ship reduces harmful atmospheric emissions and prevents oil discharge through its double hull construction. The ship operates smoothly with minimal vibrations and movements. This grants optimal vessel comfort, which is very important for the working conditions of our seafarers.”