Strengthening the sheet pile wall at the Wet Dock Quay at BAE System's Barrow-in-Furness shipyard to extend its life and allow it to service the new Astute class submarines.
Although quite a small job in comparison to others Ocean Kinetics undertake, due to the Wet Dock Quay falling within the nuclear licence boundary the work had to be carried out to the highest standards.
The job involved over plating works to the sheet pile wall under the quay. Ocean Kinetics was selected by BAE for this project because of its extensive experience of this type of work. The fact that Ocean Kinetics has its own fabrication facility helped reduce the risk to the client.
strengthening plates fitted
Quay within Nuclear Licence boundary
of underwater welding completed
Working from a dive truck on top of the quay, divers fitted strengthening plates under the quay to the sheet pile wall, where they would be welded to the piles.
Some of the plates to be installed were below seabed level. This meant the divers had to airlift down 1.2m below seabed level and lay heavy rubber mats down so that the silt would not be kicked up while the plates were being welded.
In total, 48 strengthening plates ranging from 2m to 3.75m in length were fitted.
The work was overseen by Chief Civil Engineers from both the Nuclear Facilities and the Design Authority from BAE, with Jacobs providing design support.
Two of our most experienced welders, Michael Fox and Joe Coughlin, who both have AWS class A welding certificates, carried out more than 300m of underwater welding to the highest standards.
The welds were inspected by means of MPI and ultrasonic techniques as well as 100% close video inspection, which was viewed by a BAE welding inspector.
Submarine Solutions welding and inspection department supported the works, checking sample welds at the weld test centre and reviewing video images. Within the 300m of underwater welds carried out, only three very minor defects were identified.
The project was completed within the two month period allowed for the works, well ahead of the launch date of the next submarine.
“Ocean Kinetics have more than achieved the standards we have set.”