All About Underwater Welding

If you ask people, what are some of the most dangerous jobs out there? You will hear many people mention underwater welding in their list. Yet this job is also of high demand and thus, provides a high return.

Underwater welding is a specialized form of welding, which is mainly used to maintain and repair bridges, dams, large ships, oil rigs, and sometimes even nuclear power facilities.

The basic process of this job is almost as same as dry welding. But what makes this job so much more specialized and riskier? Keep reading to know more.

What Is Underwater Welding?

Underwater welding has been around since the 1930s. It is basically welding while staying underwater by divers who have been trained professionally. This kind of welding can be done in two ways – either directly underwater, or by using a separate dry chamber.

Even though this job sounds pretty much the same as dry welding, it is far more dangerous. Even on dry land, welding techniques are quite risky. Doing the same procedures underwater only adds to that risk.

That is why to be an underwater welder, a lot of requirements has to be fulfilled in order to ensure safety to all stakeholders.

What Are the Processes?

Underwater welding can mainly be done in two ways – wet or dry. Each of these processes is described below:

1. Wet Welding

In wet welding, the diver does the job directly underwater. No separate chamber is used here, which is why divers can roam around the welding area and work quite easily than they could if their movements were limited to the insides of a chamber. However, not all of wet welding is advantageous.

While wet welding, the diver has to ensure that all materials are waterproof and safe to use while exposed to water. One of the most commonly used wet welding technique is the stick welding or the Shielded metal arc welding.

In this technique, an electric arc is used between the electrode that the diver uses to weld metals together, and the metals he wants to weld.

To properly perform the welding job, the diver first needs to assess his surrounding areas and make sure there are no safety hazards nearby. He should also steer away from any populated areas underwater. Then he should proceed to weld.

Wet welding is riskier than dry water welding in the sense that it is far easier to get electrocuted while using this technique. Therefore, preventive measures must be taken to ensure minimum risk.

The diver must see to it that the electrodes he will be using are clean and properly insulated. He also needs to keep an eye on the electricity levels every moment.

While welding, electrocution is also prevented by the thick layer of gaseous bubbles that emit from the electrode. This layer goes on to create a barrier between the workpiece and the water, thus creating a safe space.

Also, usually while wet welding, direct current is used instead of alternating current to ensure maximum safety.

Wet welding is usually only used in emergency situations, or as an option when nothing else will absolutely work. This method is not preferred by most welders due to the high risk that comes with working underwater and the lack of visibility.

Also, the quality of the work might be affected due to cracking of the metals by cooling down too quickly in contact with the water.

Advantages of Wet Welding

  • Inexpensive
  • No hassle of constructions
  • Welders can access the area with ease

2. Dry Water Welding

Dry water welding is a common form of underwater welding and preferred more over wet welding. It is usually done in a chamber placed underwater, so that the welder stays dry and can work with more precision. The chamber is filled with gases instead of water, thus creating a dry environment.

There are mainly two types of dry water welding – cofferdam and hyperbaric.

  • Cofferdam Welding

In this technique, a chamber is fixed and sealed around the welding area. The water is flushed out mainly by using valves.

  • Hyperbaric welding

To perform this procedure, first, a chamber is placed around the structure that has to be welded. The chamber is then sealed, and all the water is replaced with a mixture of gases (usually helium and oxygen)

The pressure is maintained at such a level that the welder or the team of welders do not feel any decompression sickness. Other team members control fans to fill the chamber with clean air.

Welders usually use one of four techniques to dry water weld. These techniques are – Pressure Welding, Habitat Welding, Dry Chamber Welding, and Dry Spot Welding. Each technique is used for a different chamber size, which again depends on the structure that needs to be welded.

Although dry water welding minimizes the risk of welding underwater and gives the welders the option to work with more precision and accuracy, it is not always feasible. Creating a chamber, sealing it, replacing the water with gas, all these procedures are expensive and cannot always be done. In such cases, wet welding is the only option left.

Advantages of Dry Water Welding

  • Less risky
  • The job can be done more accurately

Dangers of Underwater Welding

By now, you must have understood that welding underwater involves a lot of hazards. These following points will give you a more detailed view of the dangers that are associated with underwater welding.

Drowning

Even after taking every sort of precautions available, you sometimes cannot just avoid nearly drowning. Even very experienced divers have faced this. Therefore, safety measures need to be taken.

Drowning usually occurs when there are a lot of obstacles underwater, or when the welder is carrying equipment that is faulty. Even cases of welders getting tangled in their own equipment are not unknown. Besides, poor visibility in deeper water contributes to not seeing obstacles beforehand.

Before diving into the water, you must check all his equipment and make sure his air supply tank is full. Even after taking all precautions, if you do get in a situation like this, considering losing some of the less important equipment so that you may lose some weight and float upwards.

Hypothermia

Another common danger associated with this job is hypothermia. A huge change of temperature occurs as the welder gets into the water from the surface. As a result, his body loses a lot of heat.

This loss of heat can cause a lot of problems, even organ failure. The longer the welder stays in the water, the greater the potential risks.

To prevent this problem, it is a must to wear an insulated rubber suit that will prevent the rapid loss of heat from the body.

Explosion

While working underwater, you cannot eliminate the risk of explosions. This risk is usually the greatest in offshore welding areas, where a huge amount of fuel is stored in oil rigs. The risk is greater in deeper water.

Also, since pressurized gases are used in hyperbaric chambers, they can also contribute to the arc (that is used to weld metals) behaving erratically, and resulting in an explosion,

Electric Shock

Welding, even on completely drylands, is a job that has the chance of disasters like electrocution. Adding water to this job, therefore, only adds to the risk. This risk is mostly associated with faulty equipment.

The risk of electrocution is more potent in freshwater than offshore, as the arc often behaves erratically there.

Decompression Sickness

Another major problem underwater is decompression sickness. This problem occurs when there is a rapid change of pressure on the welder’s body, usually from diving into or going upwards in the water too fast. To prevent this problem, the diver needs to move at a steady speed.

This problem can cause nitrogen bubbles from the air tank to build up in the bloodstream of the welder, resulting in problems such as memory loss or even paralysis.

Environmental Risks

Underwater welding can be done either in freshwater such as in ponds, lakes or in salty ocean water. Both kinds of the environment have their own risks.

In freshwater, the welders have to work at shallower depths where there is a lot of currents. The current causes the welder’s arc to behave erratically, and therefore requires a lot of energy from the welder to keep it in place.

In saltwater, welders have to carry a lot of weight to minimize the effect of buoyancy. This increased weight creates a lot of pressure on the welder’s body.

Besides, in both environments, visibility is very poor. There are a lot of obstacles underwater that cannot be seen and getting entangled in those can cause the welder to drown.

Requirements for Underwater Welding

Underwater welding follows the basics of dry water welding. But as you can see, is far more complex in various ways. Therefore, the requirements that need to be fulfilled before getting into this job are also very extensive.

First of all, you need to learn the basics of welding. You can do this by getting enrolled in a school or training program designed for this. The courses can range from as little as 20 days to as long as 6 months.

After this, you need to learn commercial diving, which differs a lot from normal diving. When this step is completed, you will have to proceed to take an underwater welding course, which can take around seven months. Only after finishing all these procedures will you be ready to partake a job in underwater welding.

Salary

Underwater welding is very risky, yet why is it a job a lot of people seek? Aside from the challenging environment and the thrill of it, a common answer given by most people is – the salary.

Due to this being a high-risk job, it also offers high rewards. Most underwater welders are paid according to factors such as the project they are accomplishing, the environment they will have to dive in, the depth of the water and the obstacles involved, etc.

Inland underwater welders do not have to work in far places. They also work for normal periods of time as dry land workers and therefore receive a salary of 50,000 to 80,000 dollars per year. On the other hand, offshore welders have to travel frequently, stay away from home for long periods of time, and has longer work weeks. Therefore, they receive more than 100,000 dollars as a salary.

Conclusion

Despite this being a high-risk job, underwater welding can offer you a thrilling work environment and a handsome payment.

Therefore, this job is highly sought after by many people. So, what are you waiting for? Go get into that welding school, learn diving, and do that job that will never let you get bored.

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