Sub Hub Tow From Strangford Lough to Pembroke Dock

QED Naval required the Sub Hub (The Kraken) to be relocated from Strangford Lough in County Down, Northern Ireland, to The Challenge Welsh specialist marine engineering firm, Mainstay Marine Solutions in Pembroke, South Wales.

How Did Williams Shipping Help?

In February 2021 it was announced that QED Naval had awarded Welsh specialist marine engineering firm Mainstay Marine Solutions the contract to undertake refit works on the Sub Hub including the fabrication of new crossbeam sections and the subsequent fitting of 3 new Tocardo T1 tidal turbines to these. Shipbuilder Mainstay Marine diversified into the marine energy world in 2014 and has completed one Tidal and three Wave Energy devices since. QED Naval intends to establish an operational base at Mainstay as a result of the contract. Williams Shipping was selected for the towing operation to relocate the Sub Hub from Strangford Lough in County Down, Northern Ireland, to Pembroke, South Wales due to the suitability of vessels in its fleet and also because the company has operational bases in Pembroke, Southampton and Fawley, which suits the ongoing operational requirements for QED Naval and the TIGER project.

Williams Shipping was the obvious choice for this job as the company’s expertise encompasses complex tows and tows of sensitive equipment. Other such technical work and towage projects have involved pipelines, buoys, super yachts, the present Cowes Floating Bridge chain ferry (from Milford Haven to East Cowes), the freight-only Cross-Solent ferry Red Kestrel (from Birkenhead to Southampton), the Lymington-Yarmouth ferry Wight Sky after a serious failure (from Yarmouth to Portsmouth) and much more.

The 137gt and 2007-built Willendeavour, one of 11 vessels in the present fleet capable of towing operations, was used for the task because of the right combination of bollard pull and functionality.

The Willendeavour is a 22m long/9m beam Eurocarrier 2209 with a bollard pull of 15t and is powered by two Caterpillar C18 main engines that drive 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. The ensemble set off from Strangford on 27th May and reached its destination on 29th May 2021.

Next Phase

Once the works are completed by Mainstay Marine Solutions, the refreshed and restyled 300kw capacity Sub Hub will be towed to Southampton prior to being positioned 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.