The gravity base foundation being made by Jones Bros for Minesto’s first commercial-scale tidal device due to be installed next year off the north Wales coast is 50% complete.

The concrete base measuring 21.5 metres by 12.75 metres by 4.7 metres is being constructed at the Cammell Laird yard in Birkenhead Docks.

Jones Bros is using 465 cubic metres of concrete and the final structure will weigh close to 1300 tonnes, it said.

The foundation is hollow on the inside to allow it to be floated up the River Mersey and across the north Wales coast to Anglesey.

The structure’s cells will be filled with water to lower it to the bottom of the sea.

Once the structure is at the bottom of the Holyhead Deep, 6.5km off the coast of Anglesey, the 500kW Minesto Deep Green tidal kite will be secured to a mooring structure on the foundation.

Installation of the Holyhead Deep project device is earmarked for April.

“We’re building this foundation 12 metres deep in a dock. This has meant all materials and machines including plant have been lifted in by a crane,” said Jones Bros project manager Eryl Evans.

Image: Deep Green tidal kite (Minesto)