Kaymac were contracted to install a fish deterrent system at the new Pembroke Power Station. RWE power were constructing a new 2000MW combined cycle gas turbine power station at the site and the fish deterrent system was required to reduce the amount of fish entering the cooling water intakes and entering the fish return system.
In general, the system consisted of an open steel lattice deck supported on steel legs, which were fixed to the concrete invert in front of the cold water intakes.
The installation was carried out from the sea using two crawler cranes on a pair of pontoon barges positioned in front of the intakes.
Divers removed over two meteres of silt from the invert to allow the legs to be positioned on the invert. The legs were connected by horizontal and diagonal bracings to give rigidity, and these were attached to the bullnose piers of the concrete structure using saddle brackets.
The remaining steel work was then bolted onto the legs working from a man-riding basket suspended from one of the cranes, and then the GRP decking and handrail were installed.
A series of accoustic beacons were then installed which could be lowered from the deck down stainless steel guides to the sea bed on winches. These would emmit a low frequency sound which would deter the fish from entering the CW intake structure
Finally, to protect the structure from corrosion, each of the sixteen legs were then fitted with two 25kg sacrificial Zinc anodes installed at bed level by our dive teams.