Underwater welding techniques

Underwater welding techniquesUnderwater welding techniques
Underwater welding techniquesUnderwater welding techniques


Underwater welding techniques

The world of welding is a technical art that is both risky but absolutely necessary. It requires the same basic welding equipment and technique that one would need above the water’s surface.

Put simply, to weld something, it requires you to assemble or repair metal. With the influx of offshore ships and oil tankers across the globe, there are many ships and structures that require skilled underwater welders. This kind of technique is also used to apply weld repair on massive ships and yachts, so if you’re looking to take your welding or diving position to new heights, make sure you have the right skills.

The Hyperbaric underwater process involves high-pressure environments which can consist of two separate methods: dry (inside the dry safe chambers) and wet (welding in presence of water). In some instances, it is easy to operate at shallow depth but when the pressure increases at considerable depth, then things start to become riskier and more technical.

As you can imagine, the joining of metals underwater is not easy therefore it requires specially designed equipment to do the job. Equipment companies like Babcock provide a supply of an extensive range of welding equipment that managers can choose from. Some underwater welding equipment includes waterproof electrodes and power supply systems. These get used when a welder dives into the water to weld, directing the operator to open or cut off the current supply when required. In this process an arc is produced from a torch, which then enables it to heat the welding electrode and metal through the transfer of molten droplets. These drops are known as gas bubbles.

Here are the two key methods:


  • Dry welding

Dry welding makes use of dry champers to further provide safe and isolated environments in which welders can operate. While hyperbaric welding can be done in the open waters, it’s more commonly performed inside a specially constructed hyperbaric chamber that is dry inside.

The type of work that can be performed with dry welding is the exact same type of assembly and work that one would perform in wet welding, namely underwater pipelines, offshore oil rigs, barges and ships of all sizes. However in dry welding particularly, the electrodes are positioned in advance through a flexible port, and the welder manipulates them as he looks through windows in the enclosure.

Some of the newer, more modern chambers are completely transparent inside, especially around the area that surrounds the weld. The water is evacuated by pumping gas inside. These specially designed chambers provide not only a pleasant environment to breathe in but also a clean environment. Welders are able to regularly discharge hazardous gases while they are down there, making the process bearable.


  • Wet welding

Wet or dry-wet welding is the other underwater welding process in which the welder dives inside the water while the part to be welded is enclosed in small dry chamber. This technique is different in the sense that it doesn’t require large expensive dry chambers like the ones used in dry welding, but it is however critical to ensure that the welding equipment and components used to weld stay in a dry condition.


Safety considerations for underwater welding

When performing underwater welding, it is absolutely necessary to have the right emergency equipment that you need to prevent something disastrous from happening. This job is risky, and it requires several safety considerations that divers need to adhere to. Here are a few guidelines:


  • You need to ensure that you have an emergency air system if need be. You also need to have a team of stand-by drivers to perform a rescue or a decompression chamber to help prevent sickness from saturated diving. An additional risk when wet welding is the buildup of pockets of gas and oxygen, which can be explosive under the right conditions. Be sure to monitor these.


  • The need for the correct underwater welding equipment cannot be stressed enough. This equipment needs to be insulated and adapted to the rigours of marine environments to avoid electrical shocks. A sound communicator between the welder and surface operator is required, to monitor the current supply. If there is a problem, they should receive help immediately.


  • Management cannot allow anyone to perform these tasks without the proper skills. The diver needs to be fully-trained, with the welding and diving skills to be able to deal with these environments. Divers need to be careful that they do not inhale these hazardous gases as it could lead to fatality or serious health damage.


  • While your driver is down in the chamber and they start to develop decompression sickness, or they experience a joint or muscle pain, do not panic. This is normal and can occur to even the most skilled driver, but it needs to be carefully monitored by a diving meter or a computer.


Underwater welding techniques