Underwater Welding Requires Special Training

Offshore rigs, ships and underwater pipelines call for the special skills of a certified diver and underwater welder.  There is a reason this is the highest paid class of welders.  There are many risks involved.

Steel is the most common metal to be welded in a submerged environment. Shielded metal arc welding (SMAW) or stick welding provides the best results when used with a waterproof electrode. The electrode (stick) is coated with a special waterproof flux.  During the welding process, while the electrode is ignited, the flux burns as the metal core melts.  The gas emitted from the flux protects the molten metal to prevent contamination.  Friction welding and open water wet welding are used to repair ship hulls.

Hyperbaric or underwater welding can also be accomplished in a dry environment with the use of a specially designed habitat.  For instance, if a pipeline must be repaired, an enclosure is lowered over the area to be repaired.  A remote control from the surface activates the sides and bottom of the unit to make a water tight seal.  The water from inside the enclosure is pumped out creating a high pressure chamber.  The diver enters the chamber through a special hatch.  Welding is accomplished similar to that of land procedures and gas tungsten arc welding (TIG) can also be performed in this state.  Some companies use clear water tight enclosures that allow the diver-welder to work from the outside of the chamber.

Divers must be aware of the hazards of underwater welding.

• Sharks and marine wildlife can pose problems working under the sea.
• Visibility under water can be an issue without the proper equipment.  Special diving helmets also serve as a welding helmet to protect the welder from retinal damage caused by the intense ultra violet light from the arc.
• To prevent injury or death from electric shock, proper attire including rubber gloves must be worn.
• Build up of toxic gasses can create breathing problems.  In the case of oxygen and hydrogen mixtures, an explosion is possible.
• The bends is a term used to describe decompression sickness.  Working under high pressure conditions for a long period of time can cause nitrogen bubbles in the blood.  After the project is complete, the diver-welder must regulate his body back to the normal atmosphere by entering a decompression chamber.

Underwater welding is a critical element in the distribution of oil for energy consumption.  Certified Diver-Welders will remain in high demand in the years to come.