Another milestone achievement for Jan De Nul’s innovative intertidal trenching vehicle Sunfish
- Jan De Nul successfully reburied an export cable of Eneco’s Luchterduinen wind farm.
- A tailor-made solution was offered by modifying Jan De Nul’s in-house designed and fabricated intertidal trencher Sunfish.
- The reburial was executed without interruption of the offshore wind farm production during the entire campaign.
For the offshore wind farm Luchterduinen in The Netherlands, Jan De Nul was requested by Eneco to rebury a section of an existing export cable. To this purpose, Jan De Nul modified its in-house designed and fabricated intertidal trencher Sunfish and successfully reburied the nearshore section of the cable to a minimum depth of 2.5 metres below the seabed.
Due to morphological changes the export cable burial was over the last few years decreasing in depth within the nearshore section. To guarantee the cable will at all times remain sufficiently buried and thus protected, a reburial campaign was requested by Eneco.
Since the section of decreased burial depth was located in the nearshore zone, it was not accessible with typical offshore trenching vehicles nor could it be easily accessed from the beach. Jan De Nul offered Eneco the solution by mobilizing its intertidal trencher Sunfish. The Sunfish successfully lowered the nearshore part of the cable working up to 1 kilometre offshore and a water depth of 8.5 metres.
Tom Baguet, Project Manager at Jan De Nul Group: “Deepening the live export cable in a challenging intertidal zone with our unique in-house designed trenching vehicle Sunfish proves our expertise in various operational fields. We look back to an excellent cooperation with our client Eneco, the municipality of Noordwijk, KNRM and all local stakeholders.”
Ernest Diepstraten, Project Manager at Eneco: “Eneco greatly appreciated working together with Jan De Nul constructively in delivering this project in time and in budget. We are pleased that, thanks to the work of Jan De Nul Group, the cable to our Eneco Luchterduinen wind farm is buried deep enough again so that the wind farm can continue to supply power to our customers.”
Specifically for this project, the Sunfish was modified to a suitable post-lay jet-trenching vehicle with 2 water pumps delivering each 1250 m³/hr jet water and 3.5 m long jet swords.
It is Jan De Nul’s strength to design and engineer in-house tailor-made machines. As such, the Sunfish executed this project in its third configuration: the Sunfish was initially designed as a ploughing machine suitable for working in tidal areas. In this configuration, the Sunfish successfully buried export cables on the Race Bank project in the UK in 2016. Jan De Nul engineers converted the machine later into an excavator with a chain cutter, a configuration which was used for the burial of the Rentel export cable in Belgium in 2017. Today, the Sunfish successfully completed the Eneco Luchterduinen export cable reburial in jetting configuration by using water under high pressure.
Artemis cable tracking technology
To accurately locate the cable, the Sunfish was further equipped with 2 sets of innovative cable tracker sensors of SMD’s innovative tracking system ‘Artemis’ using the live tone of the cable. As a result, Eneco did not have to switch off the wind farm during the entire campaign.
Lee Carden, SMD Head of Sales for Artemis: “SMD very much appreciated this opportunity to continue to trial our Artemis cable tracking technology on live projects. Following a robust series of offshore trials, this project enabled live cable reburial operations to be completed without turning off windfarm power.SMD very much looks forward to continuing our collaborative relationship with Jan De Nul, who have a great history of innovative approaches to their operations.”
The Eneco Luchterduinen Wind Farm is located in the Dutch sector of the North Sea, approximately 23 kilometres off the coast between Noordwijk and Zandvoort. 43 Vestas V112 offshore wind turbines produce a combined capacity of 129 MW. From the Offshore High Voltage Station (OHVS) one 150 kV export cable of 25 kilometres directs the current to the shore.
Eneco consists of a group of companies active internationally in the field of renewable energy. Together with its customers, partners and almost 2,800 employees, Eneco works on its mission: sustainable energy for all. Eneco invests in for example wind farms, heat and solar parks to increase the supply of renewable energy.
About Jan De Nul Group
Design. Build. Connect. Jan De Nul Group shapes water and land. Worldwide. From complex services to the offshore energy and energy transition sector, over large dredging and defence works on the edge of water and land, to challenging civil and environmental works. Well integrated competences and investments lead to creative, sustainable and innovative solutions. In this way Jan De Nul Group delivers results that produce satisfied customers. Today, but also tomorrow. – www.jandenul.com
For 50 years SMD have partnered with pioneers in industry and science, to take technology and engineering to places that people have never been. SMD specialise in the design, manufacture and deployment of remotely operated and autonomous power and control solutions. SMD’s solutions help their partners around the globe to harness the potential of the most challenging subsea environments with maximum safety, efficiency and sensitivity.