DIVING & UNDERWATER SERVICES
CABLE REBURIAL REQUIRED ‘OUT OF THE BOX’ THINKING A state-of-the-art trenching vehicle has been modified to enable a tricky intertidal live export cable re-burial Jan De Nul was requested by Eneco to rebury a section of an existing export cable for the Luchterduinen offshore wind farm in The Netherlands as coastal erosion was bringing the cable closer to the surface. 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, which successfully lowered the nearshore part of the cable working up to 1 kilometre offshore and a water depth of 8.5 metres. 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 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. The Sunfish was initially designed as a ploughing machine suitable for working in tidal areas. In this configuration, it 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. 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.
8 Sunfish trenching vehicle
Falcon aids Turkish operations Saab Seaeye’s Falcon portable underwater vehicle will aid marine operations in Turkey. Turkish marine operations company, ARAS Marine will use the Falcon to support the wide range of projects it undertakes in both international and Turkish territorial waters. These projects range from marine construction and offshore supply services, to seismic research support, emergency response and salvage and wreck removal. “Equipped for the wide array of tasks ahead, ARAS’s 1000m depth-rated Falcon comes complete with a fibre optic upgrade, manipulator, soft rope cutter, cameras, Tritech
sonar and Applied Acoustics’ USBL system,” said Saab Seaeye. Modular functionality ARAS can add further systems any time as the Falcon can handle an array of cameras, sensors, tooling and complex systems typically found on much larger robotic vehicles. The ease of adding systems comes from the Falcon’s iCON intelligent distributed control architecture. Module-focused iCON provides each device with its own microprocessor for individual control - a
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concept that also makes it future-flexible for evolving technologies. The Falcon’s 20-year success comes from being a portable, metre-sized, intelligent, powerful, five-thruster, highly manoeuvrable, multi-tasking, easy to use vehicle, depth rated to 1000 metres. With a reliability record covering over a million hours underwater, including deep tunnel work, the Falcon can remain stable in turbulent waters and strong currents whilst undertaking both robust and precision tasks. The contract was negotiated through Saab Seaeye’s Turkish distributor, Aspiro.
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