Safety first for lightweight dive support vessel

The new concept dive support vessels were instructed by KD Marine of Aberdeen, which provides specialist underwater intervention services to the offshore oil and gas industry. It has been designed, in association with Seawind, by naval architect Ian Darley.

DC01 is built in aluminium supplied and cut by Laser Industries. It features a ‘V’ hull design measuring 12m LOA, with a 3.5m beam and a draft of 700mm. Propulsion is supplied by twin Cummins MerCruiser MJ 1.7 LT120hp marine diesels coupled to Cummins 1.7 MS Jet Drives.

The vessel was designed around the central lifting column and the topside of the wheelhouse has a superstructure arrangement which allows for a quick release hook to be mounted. This is accessed via a hatch from the working deck. The remit was to keep the fully laden weight below 10 tons to ensure that no alterations would need to be made to the existing lifting equipment on the mother ship.

The client wanted a vessel that would meet all the requirements to provide a safe and spacious working environment with a Lloyds Register certificated hull in a vessel which has been issued with an MCA Small Commercial Vessel and Pilot Boat Certificate for operation in area Category 3.

The final design has resulted in a craft with a large working deck area which is not impeded by the gas cylinders. These are integral to the vessel and out of sight, safely installed within the hull structure but able to be removed with little effort for inspection and maintenance.

There is an ‘A’ frame arrangement at the stern which incorporates a self-righting safety system and integral dive ladder. The ladder, complete with hand grab rails, has been designed to be a permanent fixture, with a hinged system to allow safe access to and from the working platform.

The wheelhouse provides comfortable accommodation with good all round visibility. Oversized steel frame windows and an additional ‘eyebrow’ window improves visibility when discharging from or returning to the mother ship. The topside of the whhelhouse has a superstructure arrangement allowing for all types of quick release hooks to be mounted.

The wheelhouse also incorporates a small galley area and a separate WC compartment together with plenty of space for the client to install the necessary dive equipment. The compact console has instrumentation that includes a Furuno radar system, Icom VHF marine transceiver, Icom UHF marine transceiver and a Danforth compass.

The vessel has been constructed primarily for dive support in the North Sea and on the Continental Shelf but the hull and internal layout can easily be modified to suit many other uses and is thus most adaptable for meeting the requirements of other potential clients.

A transportation cradle has also been built which enable the vessel to be moved about easily using a large forklift truck. It makes road transport that much easier and also allows work to be carried out on the vessel whilst it is sitting in a secure and dry location.

Seawind has built the vessel completely using a local, highly skilled in-house workforce which has risen to the challenge and succeeded in producing a craft that meets the high specification required by the customer. K.D. Marine will take delivery of the second dive support vessel, to be called DC02, in March of 2009.