Antwerp-based underwater repair and maintenance specialist, Hydrex, has carried out a permanent insert repair on board a 145-meter chemical tanker that had suffered a crack in its port side grey water tank.

The work was carried out during the vessel’s stop in Amsterdam.

Following an on-board and underwater inspection of the damaged area, Hydrex diver/technicians revealed that the crack was 480 mm long and had split in two at the port side end. It was decided that a 700 x 300 mm insert would need to be installed.

Hydrex fabricated the steel mobdock and the new insert plate at its base in Antwerp.

After the mobdock had been installed, the frame above the crack was removed, which allowed diver/technicians to cut away the crack and the surrounding area. The new insert plate was then positioned and welded with full penetration weld.

An independent NDT inspector approved the insert repair and the classification surveyor, who was present during the operation, gave his green light. The frame covering the affected area was then reinstalled, concluding the operation.