Ship Underwater Maintenance

Commercial Diving Services are experts in all aspects of ship underwater maintenance. Our certified commercial divers and professional trade crews have extensive experience with all ship parts including rope guards, sea chests, doubler plates, bilge keels, gratings, locking nuts, wires and anodes amongst various other parts.

Ship Rope Guard Maintenance

Rope guards are a protection barrier for propeller shafts shielding them against line entanglement around the main shafts. Typically attached by means of welding or bolted with locking wires in place. These locations can also harbour heavy marine growth at times making it difficult for inspections or repairs to be carried out.

Dive crews experienced in ship underwater maintenance carry out specialised underwater welding operations and installation of rope guards along with removal of entangled ropes and nets picked up in the ocean. Professional in-water sealing of rope guards for internal seal replacements creating a totally water tight seal for the replacements of stern tube seal replacements. Replacement and installation of anodes, rope cutters and bolts.

Ship Doubler Plate Maintenance

Doubler plates are typically used for temporary underwater repairs to the shell plating of ship hulls. Plates can be secured to the hull by underwater welding, bolted on or alternatively using high power magnetic patches depending on the specific case requirements. Our team includes qualified boilermakers with specialist skills and knowledge in fabrication. Non destructive testing (NDT) should also be carried out prior to the installation of doubler plates to ensure proper understanding of the localised condition.

Doubler Plate Underwater Welding

Our underwater welding service can securely attach doubler plates creating a water tight seal over areas of high corrosion. Some examples of locations suitable for welding are:

  • Ballast water elephant foot discharge points
  • Tank sounding pipes
  • Poor cathodic anode protection systems
  • Cracks in non fuel oil tank locations

Rare Earth Magnetic Patches

In cases where welding would not be advised our specially designed high power rare earth magnetic patches may be suitable, for example, cracks in fuel oil tanks.

Doubler Plate Bolted Via Corrosion Hole

Doubler plates can also be bolted via single located corrosion hole and in this case the plate will most likely have a flexible gasket so that when the bolt and nut is tightened through the shell plating the gasket compresses and creates a relatively water tight seal. This method is often used to allow for further internal repairs to be carried out.

Ship Sea Chest Maintenance

Sea chests are gratings located underwater on the hull of a ship typically adjacent to the engine room. Sea chests are used to draw in water through them for ballast and engine cooling. They are grated to a certain size to restrict drawing in unwanted foreign materials.

This critical underwater intake area requires constant care and upkeep to ensure a free flow of sea water. Commercial Diving Services has significant experience in cleaning, maintenance and repairs of this area.

We offer a wide range of client services when it comes to the up keep of sea chests including internal inspections equipped with telescopic cameras, removal of sea gratings, repairs to fastenings and locking wires. Our divers have the equipment and the know how to carry out removal of sea gratings whilst vessel in alongside whether it be for class inspection requirements or just for company maintenance requirements.

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