Rock as a construction material is a critical element of the marine works for Swansea Bay Tidal Lagoon, both in terms of design and in terms of construction cost.  The quality and specifications of the rock are closely linked to the stability and durability of the overall structure.

Approximately 5 million tonnes of rock of varying grades will be used in the construction of Swansea Bay Tidal Lagoon.  The project’s Marine Works Contractor will be responsible for sourcing rock and transporting it to Swansea Bay.  Tidal Lagoon Swansea Bay will re-tender the Marine Works package later this year.

As such, no decisions have been taken on the source of rock supply to the project.

TLP and its delivery partners have engaged with a range of UK and European quarries with regard to the supply of rock to the project.  Information relating to cost, quality, risk, logistics, carbon and environmental impacts will, upon appointment, be passed to the project’s Marine Works Contractor.

Shire Oak Energy, which is a shareholder in Tidal Lagoon Plc, has purchased Dean Quarry near St. Keverne, Cornwall, from CEMEX UK with a view to reopening the quarry to offer marine contractors working on UK tidal lagoon projects the option of a local source of rock suitable for building breakwaters. It formed a quarry company, Shire Oak Quarries, to make the purchase. Dean Quarry has planning permission in place until 2035 to win 6.3m tonnes of gabbro. Visit for further details.

Cornwall Against Dean Super Quarry is a campaign group which does not necessarily object to the reopening of Dean Quarry but holds concerns relating to the way in which the site may be operated.  Visit for further details.

Tidal Lagoon Power (TLP) supports both the principle of creating sustainable UK employment to serve a new UK tidal lagoon industry and the principle of a local community wishing to ensure the protection of its environment.

The participation, or otherwise, of Shire Oak Quarries in any tender to supply rock to Swansea Bay Tidal Lagoon will be determined by: the confirmation of its plans for Dean Quarry; its subsequent engagement with local stakeholders, including Cornwall Against Dean Super Quarry; the appointment of a Marine Works Contractor to Swansea Bay Tidal Lagoon; and the assessment conducted by the Marine Works Contractor of UK and European sources of rock supply, including Dean Quarry.

Tidal Lagoon Plc


T: +44 (0)1452 303892

A: Pillar & Lucy House
Merchants Road
The Docks

Tidal Lagoon (Swansea Bay) Plc


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One Central Square
CF10 1FS

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