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WÄRTSILÄ
Encyclopedia of Marine and Energy Technology

Shuttle tanker NAVION BRITANNIA

marine

According to The Motor Ship September 1998

Delivered in 1998 by Astilleros Espanoles, the 126,650dwt vessel is a twin-skeg, twin screw shuttle tanker. The double-hulled ship is specially designed for off shore loading from storage facilities at a field, or directly from production platforms and loading buoys. With 18 cargo tanks, two slop tanks and ten segregated ballast tanks, NAVION BRITANNIA has also a tank configuration and loading process designed to minimise cargo vapour emissions, and avoid spillage during loading. Cargo can be loaded either through the midships manifold, or by means of a bow loading system. A third method employs submerged turret loading from a buoy anchored to the sea bed and connected by pipeline to the production facility. Loading and discharging rates are 8000 m3/h for the bow and turret loading system, and 12,000 m3/h through the manifold. Two segregated grades of crude oil can be handled by four Kvaerner 3000 m3/h pumps. A tank radar sounding system measures the ullage in the 20 tanks, and inert-gas pressures and temperatures at three levels are also recorded. Two suction/discharge lines, aluminium heating coils in the bottoms of cargo and slop tanks, two crude oil washing lines, and a 15,000 m3/h inert gas plant are fitted.

To meet the demanding conditions associated with off shore work, the ship is equipped with a trio of retractable, controllable pitch thrusters  and two highly efficient Hamworthy rudders driven by a pair of rotary vane electro-hydraulic steering gears.

The two fully redundant engine rooms are divided by an A-60 fi re resistant, watertight bulkhead. The main switchboard is also divided into two separate units located in each engine control room. Main propulsion is by two engines with a MCR of 11,520 kW at 123 rev/ min. Each engine drives a 6 m-diameter CP propeller.

The ship is capable of acting as a well-test vessel. The foredeck has thus been strengthened to allow topsides production equipment, including a light process plant and fl are stack to be installed. The vessel has accommodation for 55 persons, although its normal complement is 22.

Length, oa: 264.68m, Length, bp: 256.50m, Breadth, mld: 42.50m, Depth, mld, to main deck: 22.00m, Draught design/scantling: 15.00m/15.65m, Deadweight design/scantling: 118,138 dwt/124,978 dwt, Service speed: 15 knots.