2021 April 26 13:15
Jan De Nul Group has signed an agreement with Osbit Ltd (UK) for the design and construction of a new subsea trenching vehicle, named Swordfish. Delivery is scheduled for the first quarter of 2022, according to the company's release.
The Swordfish will be a high-powered state-of-the-art subsea trenching vehicle that can be fitted with either a jetting installation, a mechanical chain cutter or a combination of both to tackle a wide variety of soil conditions and bury cables up to 3 or even 3.5 metres deep.
The Swordfish will be powered by 2 x 300 kW hydraulic power units and 2 x 300 kW electric HP jet pumps.
In jetting configuration, it will be capable of tackling soil strengths up to 125 kPa, thanks to its 1,120 kW of pump power. In mechanical or hybrid mode, it will be able to cope with soil strengths up to 400 kPa, using its 400 kW chain cutter tool and 420 kW additional jetting power.
The main jetting tool is combined with front cutting nozzles and additional rear backwash swords to optimize trenching performance. Thanks to the modular buoyancy the underwater weight of the vehicle in jetting mode is less than 1 tonne, resulting in a ground pressure not exceeding 5 kPa which allows trenching vehicle operation in very soft soil conditions.
The innovative chain cutter design and cable loading system minimize cable handling, plus it has the added benefit of a closed box depressor to guarantee first-time-right protection.
The trenching vehicle will be launched with a dedicated A-frame and hoisting winch from one of Jan De Nul’s offshore vessels.
Specifically for the Racebank Offshore Windfarm Export Cable project in the UK, Jan De Nul designed and built two intertidal trenching vehicles Sunfish and Moonfish that achieved an environmental and industry first. Both trenching vehicles received several industry awards for their innovative design and have subsequently been modified and used in support of several cable installation and protection projects in Europe.