From the East to the West and from huge U.S. Navy ships to smaller commercial vessels, today’s shipbuilding industry faces many challenges. Welding, of course, plays a key role in the building and maintenance of ships and other vessels throughout the United States. The welds are a critical part of a ship’s ability to be seaworthy, and it requires a variety of welding skills and equipment to make acceptable welds.
“From a global perspective, the United States is far behind in ship production,” says Rex Hardman, corporate account manager, West Coast ship, Miller Electric Mfg. LLC. “About 40 or 50 years ago, we produced about 5 percent of the world’s ships, but now we only produce about 0.2 percent. Our shipbuilding capacity has dwindled over the years, and that puts a lot of stress on existing shipbuilders to increase productivity. A sizable shipyard has about 4,000 to 5,000 employees, and to keep those people working and possibly add more, we need ships to build. To be competitive in the global market, we must be able to meet the demands of today’s shipyards.”
Hardman, who has been with Miller Electric for roughly 30 years and covers shipyards from the Mexican border to the Canadian border, goes on to explain that inroads are being made as far as increasing shipbuilding efforts are concerned.
“The good thing is that the United States recognizes the problem,” he says. “The Secretary of the Navy recently announced a large investment to revitalize shipyards – existing ones and ones that have been shut down that are trying to reopen – so that we can be more of a force in the global shipbuilding industry.”
And while the military receives the bulk of the money for building ships, the government recognizes that the commercial shipbuilding industry also must be kept strong, according to a Congressional Report Service announcement.
“I have a couple of shipyards that fit into both categories,” Hardman adds. “On the commercial side, a lot of grants are available for some smaller shipyards to revamp, whether its new dry docks, new lifting equipment or other needs. The shipping industry is about $65 billion a year on the commercial side, so if we gain even 1 percent of that, it would great. It’s tough to do, but we’re heading in the right direction.”
Welding ways
A variety of welding processes and materials are used during the construction of a ship. With a variety of processes to tackle, however, the welders as well as the equipment must be flexible to meet the needs.
“The No. 1 challenge is finding people,” Hardman says. “And the No. 2 challenge is finding qualified people that actually know how to weld. Someone who is an accomplished welder is the desired candidate.”
In building ships, wire feeding processes are the main type of welding used, and that includes gas metal arc welding (GMAW) with solid wire and flux-cored arc welding (FCAW) with flux-cored wire. According to Hardman, FCAW is currently the predominant welding process, but there is a slight shift in the shipbuilding industry toward using more solid wire due to less fume, smoke and slag creation.
The higher skilled gas tungsten arc welding (GTAW, a.k.a., TIG welding) process is also commonly found in shipbuilding. Many of the materials used – Inconel, stainless steel, copper, copper nickel – are typically called exotic metals and GTAW is very suited for welding such metals. Carbon steels are also welded using GTAW. Exotic metals are required throughout a ship for a myriad of applications, including higher end applications like nuclear vessels.
Hardman does point out that, “just because you’re an accomplished wire welder doesn’t mean that you’re going to be a good TIG welder. It is a different process and requires a different set of skills,” he says.
Finally, stick welding is still often used in shipbuilding, as well. Part of that is based on the tight areas that prohibit using the other processes and the associated equipment.
“There are just certain areas you can’t get to on a ship with a wire feeder, but you can with the stick electrode holder,” Hardman says. “The shipyards would love to get rid of it because it’s just not as fast and productive as wire welding, but it’s still used a fair amount. We sell a lot of stick rod to shipbuilders.”
The variety of welding processes and materials used in shipbuilding requires a variety of equipment that features the newest technology to make the work easier and more efficient no matter the welder skill level.
“As a manufacturer, we try to make it easier for the welder to focus on learning to weld and not having to learn the welding machine,” Hardman explains. “They still need to be able to identify the material and thickness, but once they tell the machine, the parameters will be set for them. This feature can be found on many of our machines and is typically labeled Pro-Set or Auto-Set.”
Facing obstacles
One of the biggest obstacles in the construction of ships is the extremely tight and confined spaces, which grow smaller as various areas of the ship come together, such as the stairwells and passageways. Welders, therefore, must work their way through the small spaces to get to their respective welding areas. This can be particularly challenging when they have to go up and down ladders and through holes or narrow pathways to get to the power source, which might be hundreds of feet away, to make a parameter or process change.
This is why many shipyards have switched to remote control welding technology, such as Miller’s ArcReach technology, to minimize the time spent going back and forth to the power source while maximizing arc-on time, weld quality and job safety. The ArcReach system allows welders to adjust their parameters at the weld joint.
The small spaces confronted by welders in shipbuilding environments also create a variety of safety challenges, including the need to contain weld fumes. Typical equipment in shipyards includes portable fume extractors and fume extraction guns.
“Some of the shipyards I work with are currently using fume extraction guns, and others are looking to upgrade their systems to include extraction guns,” Hardman says. “Capturing fumes at the source is the best thing we can do for the welder. The challenge is welder fatigue because fume extraction guns are heavier than conventional guns. It becomes very uncomfortable, and the welders need to take breaks more often, causing productivity to go down.”
Another solution to providing a safe work environment is to use filler metals that contain certain elements that create less harmful fumes.
“We as a wire manufacturer try to develop filler metals that don’t sacrifice strength and integrity in the weld yet are more beneficial for the welder,” Hardman says. “Also, if the wire can help them do their job faster, the welder doesn’t have to be in that environment any longer than necessary.”
Some of the welder PPE that can help mitigate weld fume exposure includes supplied air respirator (SAR) systems and powered air purifying respirator (PAPR) systems that provide respiratory protection. Beyond respiratory concerns, hot temperatures in certain areas of the United States require shipyards to take extra precautions, leading many welders to use PAPRs, which provide airflow, or SARs, which have cooling functions. While these systems are designed to lessen welder fatigue, they also add bulk to welders trying to fit in confined spaces. Manufacturers like Miller offer PAPRs with lighter weight blowers and various comfort enhancing features so it’s easier for welders to wear these for longer periods.
Overall, every shipyard has its own safety requirements, state to state, city to city, and yard to yard. OSHA governs shipyard workplace safety and requires shipyards to follow a general set of health and safety protocols. These standards require employers to take responsibility for the compliance of their employees, ensuring they are not put in jeopardy.
The equipment itself is designed for harsh environments, and shipbuilding probably takes place in harsher environments than most other manufacturing work. The equipment, therefore, has to be able to handle extreme temperatures and the drops and bumps that are inevitably going to happen.
“I recently watched a video of a guy moving to a new location that had to take his wire feeder with him,” Hardman says. “He was dragging the wire feeder with the gun, and it was just bouncing behind him on the ground. That’s the guy we have in mind when we’re designing the equipment. It has to be able to handle that kind of abuse.”
Role of automation
As the shipbuilding industry seeks new welders and the new equipment that will make it easier to train them, the use of automation is growing, as well. While some of it is driven by the lack of skilled welders, consistency is another factor.
“A lot of projects are going on right now to try to make automation more suitable to shipbuilding,” Hardman says. “Most shipbuilders already have some sort of automation, whether it’s hard automation or flexible automation or a combination of the two. One example includes using robotic arms in automated panel lines where stiffeners are added to a flat piece of steel. The robotic arms weld the stiffeners in place.
“The challenge to using automation in shipbuilding is that it’s hard to get the flexible robotic arm into places where we’d like to use it,” he continues.
Take the example of the panel line. It is fairly simple to automate because the panel is laying on the ground, the stiffeners are put in place and the welding robots are on a gantry over the top of the panel. However, the next step is to add a bunch of smaller stiffeners and other pieces in between those long stiffeners. Trying to get a robotic arm into those spots is difficult.
Whether robotic or manual welding, upstream consistency is paramount in shipbuilding. In many instances, the robot isn’t capable of providing that consistency.
“For smaller parts that are produced before they’re attached where they belong, there has to be complete consistency,” Hardman says. “The robot doesn’t have the ability to change its welding technique based on whether there’s an 1/8-in. gap or 3/16-in. gap. The skilled welder can recognize the issue and correct their weld, but if a robot is programmed for a 1/8-in. root opening and it comes in and finds the opening is 3/16 in., the robot will still make the weld but it’s going to potentially blow holes and make a mess.”
Also of note, fume extraction guns can be significantly affected by automation. The robotic or automated movement of the welding torch can make it challenging to maintain the extraction nozzle near the welding point. This can potentially lead to less effective fume extraction.
As seen through the emergence of new equipment and new approaches, the shortage of welders and the loss of knowledge taking place as older welders retire is transforming the shipbuilding industry. As the demand for ships begins to increase, so too will the need to simplify training while embracing innovative technology. Time is money in shipbuilding, and the best way to save time is to make the job as easy as possible.
