• Class approved underwater steel repairs in France and Portugal

    Class approved underwater steel repairs in France and Portugal

    19/04/2013

    Hydrex teams carried out underwater steel repairs on vessels in France and Portugal. In France Hydrex carried out a pipe repair on a 210-meter bulk carrier berthed in Dunkirk and reinforced the weld seams of a leaking doubler plate on a 183-meter tanker in Marseille. In Setubal, Portugal, two repairs were carried out on bulk carriers. An insert plate was installed on a 266-meter vessel while several doubler plates were installed on a 130-meter ship.

    On-site pipe repair in Dunkirk
    The operation in Dunkirk started with preparations for the welding work inside the engine room. At the same time a cofferdam was installed and secured underwater over the location of the boiler blow down pipe.

    The team could then disconnect the inside piping and remove the old pipe. The new pipe was then fitted, secured and welded according to the Hydrex class approved welding procedures. Once the new boiler blow down pipe was fully welded, ultrasonic testing was performed with positive results. The attending Bureau Veritas surveyor, the owner of the vessel and the ship’s superintendent were all very satisfied with the way the team performed the operation. The ship could continue its schedule without any loss of time.

    Underwater hull repair on tanker in Marseille

    The Hydrex cofferdam technique was used to reinforce the weld seams of a leaking doubler plate that had been installed in drydock on a 183-meter tanker. The operation took place in Marseille. An inspection carried out by the Hydrex diver/technician team revealed that there was a hole in the weld seam and cavitation damage was present in another area. Grinding out the damaged weld and replacing it was therefore the best solution. The team installed a cofferdam over the waterside of the affected area and then removed the weld seam over a length of 500 mm. Next they re-welded the seam to the approval of the present ABS surveyor, finishing the repair.

    Insert and doubler plate repairs in Setubal, Portugal

    A Hydrex diver/technician team installed a 640 x 300 mm insert in the bottom shell plating of a 266-meter bulk carrier during the vessel’s stay in Setubal after a 350-mm crack was found in the ship’s hull plating. After the team installed a cofferdam over the underwater side of the crack they cut away the affected area. Next they prepared the edges of the hole and installed the new insert with a full penetration weld. This was done under the supervision of the LR surveyor present during the operation. The insert repair was then successfully tested by an ultrasonic testing operator.

    In the same port five doubler plates were installed to cover the same number of cracks found in the flat bottom area of a 130-meter bulk carrier. To prevent the cracks from spreading further, the Hydrex diver/technician team first drilled crack arrests. Next they fitted the doubler plates and secured them with 3-layer welds. To meet the DNV class requirements, extra brackets were installed on the largest doubler plate (measuring 1400 x 800 mm). The vessel could then sail safely until the next scheduled drydocking where permanent repairs would be carried out.

    Conclusion
    Despite the relative size of these operations they are nonetheless vital for shipowners if they want to avoid unscheduled drydock visits for their vessels.

    Because these repairs can be carried out above or below water with tailormade mobdocks, normal commercial activities can continue without disruption while the repairs are in progress. Hull repairs are approved by the major classification societies and can save owners a great deal of trouble and money.

     To achieve this, Hydrex offers the fastest possible service to customers. Our offices have fast response centers where an extensive range of state-of-the-art tools, and diving support equipment is available at all times for the repair teams. These fast response centers enable Hydrex to mobilize diver/technician teams immediately to any location around the world.

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