Fast underwater stern tube seal replacement avoids need to drydock

Last month a Hydrex team carried out underwater stern tube seal repairs on a 192-meter roro vessel in Rotterdam. The vessel was suffering from an oil leak, making a fast repair necessary. The diver/technicians carried out the entire operation on-site and underwater using a Hydrex flexible mobdock.

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Every Hydrex office has a fast response center equipped with all the latest facilities, lightweight equipment and tools. These centers were designed specifically to increase speed of service. This allowed the company to immediately mobilize a team on one of their workboats to the vessel’s location.

The operation started with a thorough underwater inspection of the stern tube seal assembly. The divers then removed the rope guard of the vessel and installed the flexible mobdock around the stern tube seal assembly. This created a dry underwater environment to work in drydock-like conditions, a necessity for permanent stern tube seal repairs.

After cleaning the entire assembly the team removed the three damaged seals one by one and replaced them with new ones. Because the existing running area was damaged, they also installed a spacer ring to create a new running area for the seals.

The operation ended with the conducting of a pressure test with positive results, the removal of the flexible mobdock and the reinstallation of the rope guard.

A service engineer of the OEM was present during the operation and gave his approval for the replacement.

Every day a ship has to go off hire causes a substantial loss of money. The team therefore worked in shifts to perform the stern tube seal repairs within the shortest possible time frame. This saved the owner the time and money going to drydock would entail.

The team mobilized with one of the Hydrex workboats. These are fully equipped as dive support stations with hydraulic cranes, winches, nautical and communication equipment and a dive control room. They can be used for a wide range of operations in Belgium, the Netherlands, the United Kingdom and France, permitting even more rapid deployment. They allow Hydrex to mobilize throughout the entire port of Antwerp and Rotterdam within hours. This increases flexibility of operations and helps to keep costs down for the client.