Diesel electric FSV

The diesel electric propulsion system comprises two Caterpillar 3516 diesels that each produce 2350 KW and these can drive directly to the propellers via gearboxes when full speed is required. When the vessel has to operate at lower speeds such as when under dynamic positioning or when at slower speeds in harbour waters or at a rig then just one diesel engine is used and this is clutched in to drive a generator. This generator supplies the power for two electric motors that are connected to the propellers shafts via the main gearboxes and for powering the bow thruster.

In direct diesel mode the vessel’s operating speed is 20 knots while the diesel electric mode is used for speeds up to 12 knots or when dynamic positioning is engaged. With just one diesel engine in operation for the electric drive mode the fuel savings are claimed to be significant and with the electric drive there is the added bonus of the drive being able to operate right down to zero speeds which can make for much more subtle manoeuvring.

These fast supply vessels are constructed in steel to a hull design that has been developed to offer a comfortable ride in waves. With a length of 55 metres and a beam of 9 metres the hulls are relatively narrow and have a fine entry at the bow to help reduce pitching. The hull shape has been developed using multi-chines that offer a semi-rounded transverse hull shape. It is claimed that the hull design also minimises speed reduction when the vessel is operating in challenging sea conditions.

The hull is constructed from high tensile steel to help reduce weight and the design meets the requirements of Lloyds High Speed Craft rules. Provision has been made for the carriage of up to 100 passengers who are provided with comfortable seating, a self-service buffet and music and video entertainment systems similar to those found in aircraft.

The 8 man crew is accommodated in four double berth cabins and the aft cargo deck has been designed to carry 150 tonnes of cargo in the 190 square metres of space. Particular attention has been paid to the reduction of noise and vibration and the shipyard’s long experience with the construction of river passenger vessels has enabled to accommodation to be developed to a high standard.

The first two vessels in this seven vessel series have been delivered with the remainder scheduled for delivery later this year. This contract placed with a European builder is in contrast to the normal shallow draft fast support vessel or crew boat designs that have been developed by US Gulf of Mexico shipyards. The De Hoop company has shipyards in Lobith and Foxhol and focuses in the construction of specialised ships for a wide variety of applications.

By Dag Pike