Pembroke Power Station – Fish Deterrent System Installation
Pembroke Power Station – Fish Deterrent System Installation
Client: RWE Power
Location: Pembroke, South Wales
Sector: Energy & Power
Services: Marine Civil Engineering | Commercial Diving | Structural Installation | Temporary Marine Works
Project Overview
Kaymac Marine & Civil Engineering was contracted to undertake the marine installation of a fish deterrent system at the new 2,000MW Pembroke Combined Cycle Gas Turbine (CCGT) Power Station.
The system was designed to reduce the number of fish entering the power station’s cooling water (CW) intake structure and subsequently entering the fish return system.
The works required a combination of marine construction, heavy lifting, commercial diving and structural steel installation, with the majority of the installation undertaken from floating plant positioned directly in front of the cooling water intakes.
Scope of Works
The fish deterrent system comprised an open steel lattice deck supported on structural steel legs fixed to the concrete invert in front of the cooling water intake structure.
Kaymac established the marine working platform using two crawler cranes positioned on a pair of pontoon barges, enabling the structural components to be lifted and installed from the seaward side of the intake.
Prior to installation, Kaymac’s commercial dive teams removed more than two metres of accumulated silt from the invert to expose the concrete structure and allow the supporting steel legs to be accurately positioned.
The legs were interconnected using horizontal and diagonal steel bracing to provide structural rigidity. The assembly was further secured to the bullnose piers of the existing concrete intake structure using purpose-designed saddle brackets.
Once the primary support structure was established, the remaining structural steelwork was lifted into position and bolted to the supporting legs. Installation was undertaken using a man-riding basket suspended from one of the crawler cranes, providing access to the structure from the marine working platform.
The completed steel structure was subsequently fitted with GRP decking and handrails, providing safe access for operation and future maintenance.
Acoustic Fish Deterrent System
A series of acoustic beacons were installed as part of the completed system. Each beacon could be lowered from deck level via stainless-steel guides and winches to its operating position close to the seabed.
The beacons emitted low-frequency acoustic signals designed to deter fish from approaching and entering the cooling water intake structure.
Cathodic Protection
To provide long-term protection against corrosion within the marine environment, Kaymac’s dive teams installed sacrificial zinc anodes to the submerged steelwork.
Each of the 16 structural legs was fitted with two 25kg sacrificial zinc anodes at seabed level, providing cathodic protection to the completed structure.
Specialist Marine Delivery
The project demonstrates Kaymac’s ability to deliver complex marine installations where commercial diving, floating plant, heavy lifting, structural steelwork and specialist access must be coordinated within a live marine environment.
From underwater excavation and preparation through to structural installation, acoustic equipment and cathodic protection, Kaymac provided the specialist marine capability required to successfully install the fish deterrent infrastructure serving Pembroke Power Station.
