• Underwater stern tube seal repairs in Algeciras and Le Havre

    Underwater stern tube seal repairs in Algeciras and Le Havre


    The Hydrex flexible mobdock technique was used to perform two underwater stern tube seal repairs.  Three seals were replaced in Algeciras on a 250-meter roro vessel that was leaking oil, while the aft stern tube seal assembly of a 210-meter container ship was partly repositioned in Le Havre to stop an oil blockage.

    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 and allowed us to mobilize diver/technician teams to both vessels, from our offices in Algeciras Bay and our headquarters in Antwerp respectively.

    After a thorough underwater inspection, the rope guard of the vessel in Algeciras was removed. The split ring was then disconnected and brought to the surface to be cleaned. Next the Hydrex flexible mobdock was installed around the stern tube seal assembly and a dry underwater environment was created in which the diver/technicians could remove the damaged seals one by one and replace them with new ones which were prepared onshore by the attending Aegir-Marine specialist.

    After the rope guard was removed during the operation in Le Havre the diver/technicians discovered that the oil flow through the stern tube seal assembly was blocked. This was caused by the intermediate and support rings both having been turned 180 degrees the wrong way. After the flexible mobdock was installed, the assembly was opened up and all parts were closely investigated and cleaned. This inspection revealed that all seals were in good condition but that the bonding was in bad condition. The bonding of the seals was consequently repaired after which the seal assembly was refitted the proper way.

    Both operations ended with the conducting of pressure tests with positive results, the removal of the flexible mobdock and the reinstallation of the rope guard.

    The roro vessel needed to cross the ocean after its stop in Algeciras, but would not have been allowed entrance to any port in the United States due to the U.S. Coast Guard’s very strict policies concerning environmental risks. Thanks to Hydrex’s fast response, the captain could continue on his schedule with the oil leak repaired and with only a minimum of delay.

    The superintendent of the container ship in Le Havre was also very satisfied with the service offered by Hydrex. He said, “Even after the typical late call on a Friday afternoon and even later that evening, Hydrex still managed to assemble and organize a team of divers that arrived the next day in Le Havre.  The job was completed well within the available time frame, including full re-welding of the rope guard and shifting of the vessel to another berth. In between, new divers and technicians arrived, all of whom seemed very professional and skilled in their work. We used Hydrex also the week before on this ship for another job in Dunkerque and the response at that time was also very fast and professionally executed.”