Hydrex scores at home and away with afloat hull plate repairs
When a high-speed support ship arrived at a yard in Curaçao needing emergency repairs to hull plating, drydock unavailability created a new dimension to an otherwise standard repair job.
A Hydrex Underwater Technology technical dive team was mobilised to the Caribbean island to figure out a solution.
Hydrex Production Executive Dave Bleyenberg, explained: “The shipyard and the owner agreed that our idea to build a cofferdam was the optimum solution, allowing yard staff to carry out the work from inside the vessel at its berth. The difficulty lay in the fact that the vessel had an aluminium hull, preventing any wet welding work.
“The hull had been damaged in two locations so we planned to move the cofferdam to the next area after completion of the first repair. Because of the deformation of the bottom plating, we had to build a second cofferdam and cover up both damaged areas at the same time. This proved to be the much quicker solution and resulted in us finishing the job well before drydock space became available, much to the satisfaction of the owner.”
In less warmer climes, Hydrex divers were called out to Zeebrugge, Belgium, to repair the hull of ro-ro vessel that had collided with a quay wall.
“The operation started with a detailed underwater inspection of the damage, said Bleyenberg. “ This revealed a 780mm long crack on the bulbous bow, two metres under the waterline. Crack arrests were drilled on each side of the damaged area to prevent the crack from spreading further, after which a 850mm x 60mm doubler plate was positioned over the damage and secured with wet welds.”
Leak tests confirmed the integrity of the repair, which was subsequently approved by the classification society.
“While this was not a complicated project, the nature of the emergency repair demanded an immediate response due to the type of vessel. We managed to repair the vessel without disrupting its tight operational schedule.
“Both vessels were able to continue sailing without the need to drydock, saving their owners considerable time and money,” said Bleyenberg.