Aquatera wraps up Jee system

Stromness-based Aquatera has completed deployment and recovery of subsea engineer Jee’s intra-array cable protection system, part of Scottish Enterprise’s £2.4m Tidal Array Cabling Solution Project off Orkney.

The 50-metre long conduit, fabricated by JGC Engineering at Scrabster in Caithness, was installed off Hatston Quay near Kirkwall. The ‘U-Tube’ system, claimed to be the largest structure ever deployed in a high energy tidal site, utilises a gantry barge, two Mulitcats and one tug.

The U-Tube features a pipeline secured to turbine foundations through which a cable is fed.

The demonstration system was towed several hundred metres from shore and attached to the seabed and a test cable installed following deployment.

The vessel spread used included a specialised heavy-lift barge – belonging to Stromness firm Green Marine – along with a tow vessel and MulticCat provided by Green Marine and a second MultiCat vessel operated by Scotmarine.

These vessels were supported with a quayside duel crane lift by Heddle Construction. Management of the marine operation by Aquatera was backed up by Orcades Marine.

The Aquatera role involved lifting, moving, positioning and recovering the 50m long Jee cable protection system.

Aquatera project manager said Daniel Wise: “The installation, operation and recovery of the Jee cable protection structure was a unique, interesting and challenging marine operation, one which required meticulous planning and execution, but the barge and other vessels proved to be the ideal solution, with the operation running very smoothly.”

Wise said a second project to test a range of different cable laying configurations would be completed later this year.

In the coming months Jee, alongside Aquatera, will be presenting the results of the trial demonstrations to Scottish Enterprise and their steering group members, along with other interested organisations from within the renewables sector.

 Image: Multicat (Damen)