Underwater course screen removal
James Fisher Marine Services (JFMS) engineered a marine solution for an underwater coarse screen that became detached at a nuclear power station.
Providing a bespoke solution to the removal of an underwater CW 4 north coarse screen, JFMS had to work closely with the customer to ensure the delivery of an efficient project solution, focusing on minimising operational downtime by enabling adjacent outlets to remain open.
The coarse screen was jammed in a position where it couldn’t be retrieved through a direct lift, so JFMS had to mobilise a full dive spread and personnel to deliver a bespoke solution for retrieving the screen which included diver intervention.
Utilising the Yorkshire Lady, the team moored in front of the coarse screen providing a safe and efficient dive position to access the screens where the divers could be closely tendered, enabling the adjacent intakes to remain operational - further minimising operational downtime.
The divers installed nine air bags to the detached coarse screen with varying lift capability of 250kg to 2T, which was calculated to lift and support a total of 4.5T, including the additional weight of marine growth.
Divers prepared the lift by removing any potential snags so that the air bags could be inflated in stages to raise the screen with the tide where it could then by finally removed from the water by crane.