Rigdon Marine has the Orleans, first of ten 210 x 54.1 x 19 ft. (64 x 16.5 x 5.8-m) diesel-electric ABS Classed DP-2 platform supply vessels's from Bender Shipyards, now working in the Gulf of Mexico
. A second vessel, the Bourbon, was to follow at the end of June with a third, the Royal, in August. These will be followed by seven more of these innovative vessels. The announcement of the ambitious build program, by Rigdon in 2002, received wide spread industry attention. Fernando Malabet of the boats' designer Guido Perla & Associates explains that the diesel electric propulsion system will provide superior performance in the dynamic positioning mode and maximize the design efficiency eliminating the need for long shafts and reduction gears.
The heart of the propulsion system for each of the new DP capable boats is a pair of Cummins (CMI)
Marine QSK60-D(M) Marine Generators. The 16-cylinder four-stroke engines each develop 2,548 bhp (1,901 kW) at 1,800 rpm which in turn produces 1,825 kWe at 60 Hz . The generators power electrical motors that will turn a pair of Steerprop SP-18T 360-degree azimuthing drives with open 2300 m/m propellers.
The responsiveness of the diesel electric drives enables the propulsion system to more readily meet the demands of the vessels' level 2 dynamic positioning system. Additional electrical power is provided by a Cummins KTA-38-D (M) powered 900 kW generator set. Cargo provisions include 1200 metric tonnes of deck cargo carried on the 41.8 X 13.7-metre open aft deck. The deck is strengthened for up five tonnes per cubic metre. The vessels' tankage includes 765 cubic metres for fuel, 819.7 cubic metres for drilling mud and 202 cubic metres for bulk mud. Cargo water and ship's water will be 670.8 and 74.3 cubic metres respectively. Lube oil is stored in fore and aft tanks of 7.2 and 9.2 cubic metres.
The Orleans, with accommodation for 22 people has an operational speed of 13 knots loaded at a 4.9 metre loadline. Delivery of the balance of these boats will continue through 2005.