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.
Wouter Vermeersch, Manager Offshore Cables at Jan De Nul Group: “The Swordfish makes the perfect addition to our existing fleet of trenching vehicles providing excellent protection for cables installed by any of our Cable Laying Vessels. With its high power, the Swordfish will be able to bury the cables deeper and thanks to its hybrid mechanical chain cutting configuration the Swordfish can also tackle more challenging soil conditions, including hard clays up to 400 kPa. This new investment, together with the recent acquisition of our cable installation vessel Connector, arms Jan De Nul Group for the energy transition of tomorrow. We look forward to working together with Osbit Ltd (UK) on this project and to offer customers the best solution for their cable projects.”
Robbie Blakeman, Joint Managing Director at Osbit Ltd (UK): “We are delighted that Jan De Nul has selected Osbit to supply the Swordfish trenching vehicle. We worked closely with Jan De Nul on specifications and drew from our in house trenching expertise and proven technology base to develop this market leading subsea vehicle. We pride ourselves on serving a global market and as a UK based company with a predominantly local supply chain, this projects allows us to continue to strengthen our exports of specialist equipment to mainland Europe. Furthermore, it allows us to continue to invest in our people, critically the development of highly skilled engineering roles at our home base in the North East of England. We look forward to collaborating closely with Jan De Nul throughout this exciting project and delivering the Swordfish on time and fully operational for its first campaign.”
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.
A brother for Sunfish and Moonfish
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.