Specialist tow for sensitive ‘monster’
Expertise in complex tows and tows of sensitive equipment saw Williams Shipping as first choice for relocating the Sub Hub tidal energy device, also known as The Kraken, from Strangford Lough in County Down, Northern Ireland, to Pembroke, South Wales to undergo refit.
Developed by QED Naval, the Sub Hub is a submersible, gravity based, foundation platform for the commissioning, testing, transportation, and installation of an array of wave and tidal turbines. Designed to be easy and cost effective to install, Sub Hub supports tidal turbines life from integration ashore to deployment, installation and retrieval for maintenance and finally decommissioning.
One of 11 vessels in the present Williams Shipping fleet capable of towing operations, the 22m long/9m beam Eurocarrier 2209 ‘Willendeavour’ was selected for the towing task due to the right combination of bollard pull (15t) and functionality. Powered by two Caterpillar C18 main engines driving two 1,350mm diameter 4-blade fixed pitch propellers in nozzles, the 9-knot ‘Willendeavour’ easily took the job in her stride as the towing speed was limited to just 3 knots; a slow and steady pull for the 60-hour passage (approx. 200 nautical miles) from Strangford Lough to Pembroke.
Mainstay Marine Solutions is carrying out the refit works including the fabrication of new crossbeam sections to support the subsequent fitting of 3 new Tocardo T1 tidal turbines. Shipbuilder Mainstay Marine has completed one Tidal and three Wave Energy devices since diversifying into the marine energy world in 2014.
The refit is expected to be completed by early November when the refreshed and restyled 300kW capacity Sub Hub will once again be under tow, this time to Southampton prior to being positioned, subject to planning and consent agreements, on a permanent mooring in the Solent to the west of Yarmouth, Isle of Wight, at a location between Sconce Point and Black Rock. The currents here are strong thanks to the narrowest part of the Solent, the Hurst Narrows. These upcoming trials at the test site are expected to validate the associated design tools and processes for tidal power generation.
Exhibitor: Williams Shipping Ltd