Project Overview

Dawnus successfully carried out enabling and marine work packages at Pembroke Power Station which is a Combined Cycle Gas Turbine (CCGT) plant. The enabling works included site investigation works, a 50,000m³ earthworks operation, a 40,000m² piling mat to the main power island site, extensive drainage, service installation and road infrastructure. We negotiated significant temporary works packages to the power island – designing and installing cofferdams up to 8m deep.

Following successful completion of the enabling works we secured some very technically demanding projects on the cooling water intake and outfall system. This involved significant works to an existing reinforced concrete structure built to support the old oil fired power station. Works included installation of new valves, concrete repairs and structural alterations, installation of a fish return system and all civil works to support the mechanical infrastructure.

Works to the cooling water outfall involved concrete repairs to the outfall tunnel pipework (approximately 400m long and up to 30m deep), removal of existing concrete plugs and installation of new headwalls and flap valves. For all works, significant temporary works and design input was required as the works were very much method led, with a lot of the works being carried out from barges and underwater with divers.

Project Gallery


Alstom Power



Project Value


Contract Period

70 weeks