VESSEL CONVERSION | Sanco Sailor – Research vessel rebuilt for seismic source work

The DP system itself is a Kongsberg KPOS DP2, paired with Kongsberg track steering running dedicated software for line-keeping during acquisition. Electrical distribution is at 690V, 440V and 230V, all at 60 Hz, and emergency and auxiliary generation comprises one 250kW unit and one 1,190kW unit.

The propulsion plant is the original diesel-mechanical arrangement. Four MAN 32/40 engines, two of 4,500 kW (6,000 hp) and two of 3,000 kW (4,000 hp), drive two controllable-pitch propellers through two Flender twin-in, single-out gearboxes, giving 7,500 kW (10,000 hp) per shaft and 15,000 kW (20,000 hp) in total.

Station-keeping and manoeuvring rely on three thrusters: a retractable, fixed-rpm, controllable-pitch bow unit of 1,500 kW, a Rolls-Royce (now Kongsberg) tunnel bow thruster of 1,250 kW and a Rolls-Royce tunnel stern thruster of 750 kW. The specification gives a bollard pull of 216 tonnes.

Maximum speed is approximately 18 knots at 65 cubic metres (15,000 gallons) of fuel a day, service speed is 12 to 14 knots at 30 cubic metres (6,600 gallons) a day and economic speed is 10 knots at 23 cubic metres (5,100 gallons) a day. Seismic shooting is 4.5 knots and 20 cubic metres (4,400 gallons) a day, a figure that includes the load from the compressor plant.