Tidewater Builds Diesel Electric
Tidewater began with the 1955 launch of the Ebb Tide, the first purpose-built boats to serve the Gulf of Mexico offshore oil industry. With over 400 vessels currently serving the oil industry worldwide the company is now the largest offshore support vessel operator in the world. The fleet has been built by acquiring competitors but also by an extensive and systematic new construction program.
Currently the latest generation of platform supply vessels have completed the design phase. MMC Ship Design & Marine Consulting Ltd of Poland designed the vessels, 12 of which are being built in China at the Fujian Mawei Shipbuilding Ltd.
The new class of platform supply vessels will be diesel-electric powered. Each of the four electric generators will be turned by a Cummins QSK60-D(M) rated at 1825 kW. These provide the electrical power to the two motor-driven aft mounted azimuthing thrusters and two bow thrusters, a 910 kw controllable pitch tunnel thruster along with an 800 kW drop down controllable azimuthing thruster. Power will also be reserved for the vessels cargo systems.The boats have a 14.3-knot design speed.
In the choice of propulsion Tidewater has moved to the efficiencies offered by diesel-electric technology. The great flexibility of this system allows for significant cost savings when a boat is on standby at an oilrig or maintaining slow speeds for exploration jobs. One or more of the engines can be shut down when full power is not required. When linked the vessels dynamic positioning system, the diesel electric system can deliver just the right amount of power to the bow and stern drives while the big diesel engines maintain a constant speed as the need for revving the engines up and down is negated by the control of the electric motors.
The engines and generators will be mounted forward in the vessels 286 by 61.6 by 24.3 ft hulls. The hulls will also have tanks with capacities for 249,642.6 gal of fuel, 163,786.7 gal of water, 475,509.7 gal of ballast and/or drill water and 660,430 gal of liquid mud. The vessels will also be methanol capable.
They will be able to handle up to 3550 metric tons of deck cargo on the 35,315 square ft of deck space. Deck equipment will include a stores crane two ten-ton tugger winches and a rescue boat. Accommodation will be provided for a complement of 52 persons.
The Vanuata-flagged vessels will be classed by ABS as A1,(E) Offshore Support Vessel, AMS, DPS 2 and FFV Class 1. The first of the 12 vessel series will deliver in 2010.