• Ultra-fast response allows for emergency underwater seal repair in record time

    Ultra-fast response allows for emergency underwater seal repair in record time


    A 134-meter chemical tanker suffered a leak to its stern tube seal assembly while berthed in Antwerp. The Port Authority demanded that an underwater inspection was carried out and an on-site solution was found before the vessel would be given the green light to sail again. We were contacted by the owner of the ship to perform the inspection and follow up repair in the absolute minimum amount of time.

    The crew of the vessel had been able to temporary halt the leakage, but the Port would not let the ship continue on her schedule before an inspection had been done. We therefore mobilized a team from our headquarters to the chemical tanker immediately after the call came in.

    The underwater survey revealed that the temporary fix had not stopped the oil leak completely. A replacement of all four stern tube seals was needed. Because the vessel had just been fully loaded in Antwerp, trimming the vessel was not an option. The repair would therefore have to be performed underwater and on-site.

    We have been replacing seals underwater for 15 years with our award winning flexible mobdock technique. This allowed us to devise a repair plan very quickly after the inspection. The owner gladly accepted the proposal as it would give him the opportunity to continue on his schedule with only a minimal of delay.

    A to Z repair package
    Because of our many years of relationships with OEMs, we were able to arrange for spare parts to be sent to Antwerp immediately. An engineer of the stern tube seal manufacturer mobilized at the same time.

    We have a very large stock of seal repair equipment stored in our fast response centers for a wide range of operations. As soon as the repair was confirmed, a team of diver/technicians loaded everything they needed on one of our dive support workboats and sailed to the tanker.

    While the new seals were prepared for installation by the engineer of the manufacturer, the team dismantled the vessel’s rope guard. Next the divers installed the flexible mobdock around the stern tube seal assembly, creating a dry underwater environment. Because the tanker had a smaller liner than most vessels, the mobdock was adapted to accommodate this. This was easily done by the team.

    The split ring was then disconnected and brought to the surface to be cleaned. After cleaning the entire assembly, the team removed the damaged seals one by one and replaced them with new ones.

    All parts of the stern tube seal assembly were then reinstalled and secured. Leakage tests were carried out, to the satisfaction of the representative of the OEM. Finally, the divers removed the flexible mobdock and reinstalled the rope guard.

    By organizing everything from start to finish and in record time, the owner did not have to worry about making any arrangements for the repair. He could sail his vessel to her next stop without any unnecessary delay to the schedule.

    The team was congratulated by the Technical Superintendent of the vessel for the “very professional job”, as well as by the Fleet Director who called the operation “an additional success for Hydrex!”