There are shipyards that build ships, and there are shipyards that build ships efficiently by staying on the cutting edge of technology. Dakota Creek Industries (DCI) in Anacortes, Washington, is one of the latter.

To reduce operator stress and to weld as efficiently as possible, Dakota Creek Industries is converting its welding fleet to the newest technology.

Two products from Miller Electric Mfg. Co. feature prominently in this conversion: The compact, lightweight SuitCase X-TREME 8VS wire feeder and multi-operator “inverter racks” with welders such as the XMT 350 that is equipped with Auto-Line power management technology.

The SuitCase X-TREME 8VS feeders weigh 34 percent less and are 43 percent smaller than Dakota Creek Industries' previous feeders. By lowering weight and increasing maneuverability, these feeders reduce operator stress. Considering that Dakota Creek Industries, a self-insured company, pays $3,200 for a typical strain injury, promoting operator wellness pays big dividends.

Dakota Creek Industries' 6-arc inverter racks pay even bigger dividends. Because a CC/CV inverter with an output of 425 amps can perform every welding process required — stick, gas tungsten arc welding (TIG), metal inert gas welding (MIG), flux cored and carbon arc gouging with 5/16-in.-diameter carbons — Dakota Creek Industries operators do not need to swap machines or reroute leads when switching processes.

While Dakota Creek Industries' actual savings remain confidential, a similar shipyard with 50 welding operators — but using older welding technology — potentially would spend $180,000 per year (4,000 man-hours) changing leads. If this theoretical shipyard invested in eight new 6-arc inverter racks that cost approximately $200,000, the efficiency of these inverter racks would provide a payback in just 18 months and provide a 66 percent return on the investment.

Defect Free

Founded in 1975, Dakota Creek Industries today employs 290 people and fabricates and repairs tugs and barges, steel and aluminum yachts and high-speed aluminum ferries.

Stationed on the deepwater Guemes Channel, Dakota Creek Industries can build and repair larger vessels. The company has earned a reputation for quality workmanship, getting repeat local business and garnering new customers from across the country.

For example, Dakota Creek Industries' newest effort involves fabricating the offshore oilfield vessels the Grant Candies, which is 292-ft. long × 59-ft. wide; and the Ross Candies, which is 309-ft. long × 65 ½-ft. wide, both of which are bound for the Gulf of Mexico.

All of Dakota Creek Industries' welds must meet standards set by such organizations as the American Bureau of Shipping (ABS), U.S. Coast Guard or Lloyd's Register. All seams must be X-ray quality, and all fillet welds must be free of defects.

Each project has specific delivery dates that, if not met, lead to penalty fees. While each ship varies, most are built from A36 ABS Grade A steel with other components built of grades AH, EH, stainless steel and aluminum. The Grant Candies and the Ross Candies feature steel ranging from 5/16 in. to 2-in. thick.

While Dakota Creek Industries mostly uses the flux cored welding process — the Grant Candies consumed about 50,000 lbs. of E71T-1 flux-cored wire — the process for steel-hull vessels starts by using an E6010 stick electrode for all open-root butt welds, seam welds and hole seams. While initially slower, the stick process provides better quality and lower overall cycle time in this application.

“On open root welds, we found that running flux-cored wire drew in atmosphere from the back side of the weld,” Wes Hill, Dakota Creek Industries welding supervisor, said.

“Atmospheric contamination creates pin holes in the weld, which means that we would have to dig deeper when back gouging the weld. That takes more time and makes it more difficult to ensure weld quality,” Hill said.

Hill refers to the fact that welding codes require back gouging all welds down to new metal and welding from both sides of the plate to ensure complete fusion.

The need to shift between the stick, flux cored and air carbon arc gouging processes prompted Dakota Creek Industries to jettison its old welding units and adopt multiprocess (CC/CV) inverters and multi-operator inverter racks.

“The time savings of CC/CV inverters is huge. You can stick, air-arc, wire feed and TIG with the same machine. That saves the operators several hours a day by eliminating the need to look for and trade power sources with another operator and then rerouting welding leads,” Hill said.

As Dakota Creek Industries is still in the process of phasing out its older welding units, Hill knows from painful experience that it typically takes an operator about two hours to swap machines and reroute leads.

Even if an operator only needs to do this twice per week, the large number of welders in typical shipyards adds up to several thousand man-hours of wasted time and hundreds of thousands of dollars in lost profits.

However, now that Dakota Creek Industries has more than 20 six-arc inverter racks and numerous individual inverters strategically located throughout the yard, its operators rarely need to change machines.

Steady Course

The XMT 350 features Miller's exclusive Auto-Line power management technology.

Auto-Line technology provides three key benefits that improve performance: the ability to maintain a rock-steady arc despite primary power fluctuations within a 190 to 630-V range; a primary power draw of just 17.8 amps at rated output on 460 VAC primary, which is a 25 percent advantage over competitive 350-amp inverters; and the flexibility to accept any type of primary power — 190V to 630V, single-phase or three-phase, 50Hz or 60Hz — without physical linking mechanisms.

Auto-Line technology uses a “boost converter.” That boosts the primary input power — whether it's 208V, 220V, 240V, 460V, 575V or anything in between — to a higher voltage. After being regulated, the power then becomes the source voltage for the actual inverter section of the power source. That ensures that the inverter has sufficient power as long as the primary power remains within a +37 percent to -59 percent of the nominal 460-V power.

For companies where dirty power created issues that led to blown circuit boards or capacitors on inverters with physical linking systems — and Dakota Creek Industries was one of these — the XMT 350 provides a solution.

“You're better off going to the newer inverters and getting rid of your older machines. New inverters also will draw a lot fewer amps, and finding sufficient power can sometimes be a challenge,” Hill said.

In addition to surviving dirty power conditions, the inverters also survive harsh shipyard conditions.

“The Pacific Northwest is famous for its rain, but Miller inverters have held up extremely well in this wet environment,” Alan Robertson, a sales representative with Central Welding Supply, said. “Between the salt air, sand blasting and painting in the shipyard, plus moving equipment around all the time, Dakota Creek represents pretty harsh conditions,” he added.

Trial by Water

Because Dakota Creek Industries represents a real-world torture test, Robertson consistently brings them new welding technology to assess.

“If it's going to get broken, we're going to break it,” Matt Purcell, weld lead for Dakota Creek Industries, said.

When Miller began to introduce its new SuitCase X-TREME 8VS wire feeder, a product especially designed for shipyards, Robertson thought of Dakota Creek Industries.

Robertson has helped Dakota Creek Industries move from large, steel-covered suitcase-style feeders that were heavy and could barely fit through a porthole to heavy-duty plastic-cased feeders, then to the SuitCase X-TREME 8VS, which is small enough to fit through a 14-in. hole. The wire feeder is 12¾ in. × 7¼ in.

“The average ‘lightning hole’ we crawl through is a 24 in. × 18-in. oval. By going to the X-TREME 8VS wire feeders, we cut the weight down by 35 lbs. That cuts the weight in half and makes it much easier for the operator,” Hill said.

The X-TREME 8VS holds an 8-in. spool of .030 in. to .062-in. flux cored wire. The smaller size means that operators must change out wire spools more often, but the lighter weight and improved accessibility offers a greater advantage.

“Even though we have to change out the wires more often, it's better because it saves us time by making employees more productive. They are happier using this equipment, and it saves us time and cost due to injuries,” Purcell said.

The X-TREME 8VS is built to withstand the damp and dirty atmosphere inherent to metalworking in a shipyard. It has a polypropylene case that is designed to withstand bumps and bruises while keeping out the combination of water and dirt, metal and dust that can adversely affect wire feeder performance. The feeder features a circuit board dipped in epoxy to protect it.

Dakota Creek Industries also reports that the X-TREME 8VS feeders offer excellent arc starts and performance that cuts down on the weld repair time associated with wire stubbing.

“The soft arc is nice. The arc just starts out crisper, and the weld puddle wets better. The wire doesn't ‘noodle’ the way it did with our older feeders,” Hill said.

The primary benefit of the X-TREME 8VS feeder, however, is reduced operator strain.

That ranges from the basic effort saved by lifting and carrying a lighter machine to a reduction in injuries caused by heavier equipment. Dakota Creek Industries claims that the lower weight reduces the number of work-related strains. Not only does this reduce medical bills, it prevents downtime associated with injuries and guarantees that more work is completed in a shorter period of time.

“The average cost for a strain injury is $3,200, and that's on the low end. Lighter-weight feeders help prevent strain injuries and improve overall operator efficiency. That's a lot better alternative than having some miss work time or paying out any money for insurance and medical bills,” Hill said.

King of the Sea

The combination of the XMT 350 and X-TREME 8VS wire feeder have helped Dakota Creek Industries reduce the hassles associated with welding as its work gets larger and more complicated.

Configuring the multi-process power sources in packs of eight and six that can be easily moved from module to module has helped to reduce operating costs and downtime. Lighter-weight wire feeders have reduced work-related injuries and made it easier for welders to perform difficult welds in tight and unforgiving conditions. These changes have helped the company more efficiently produce a product they are respected for.

“When a boat leaves here, we like it to be the best boat possible. That's why we get return customers. People who have had ships built by others even come to us for repair because Dakota Creek has built its reputation on quality craftsmanship,” Hill said.