Application Stories

Lincoln Electric Keeps Production Moving on Challenging Aluminum Ship Project
 

Material Specifications and Quick Turnaround Requirements Drive Great Lakes Shipyard Welding Efficiency Gains


“. . . we realized the programmable Power Wave® 355M would take us to the next step . . . it really simplified the process for our welders."

 

When the U.S. Geological Survey (USGS) approached Great Lakes Shipyard in Cleveland last June, the government research agency had a tall order: To build two new, 70-foot aluminum vessels for delivery before September 2011.

For the USGS, the $8.2 million contract meant the agency would finally replace two of its oldest research vessels in its Great Lakes fleet with “floating laboratories” equipped with state-of-the-art instrumentation designed to improve the understanding of deep-water ecosystems and fish species in Lake Erie and Lake Ontario.

Great Lakes Shipyard 
For Great Lakes Shipyard, a division of the Great Lakes Towing Company located on Cuyahoga River’s Old River Channel just off of Lake Erie, the order posed the ship designer and fabricator’s biggest challenge in recent history – designing and fabricating not one, but two aluminum ships, something the company had yet to do.

The USGS, which is funding the new construction through the American Recovery and Reinvestment Act, will moor one ship at the USGS Lake Erie Biological Station in Sandusky, Ohio, and the other at the USGS Lake Ontario Biological Station in Oswego, N.Y.

 Great Lakes Shipyard Aluminum Specifications
The agency, which approached Great Lakes with basic preliminary designs, chose to build the two vessels out of 5083 aluminum alloy after performing a feasibility study, says Christopher C. Peifer, Great Lakes assistant vice president of engineering and the company’s safety officer.

“The three biggest factors that drove them to choosing aluminum were draft, speed, and weight,” he explains. “Lake Erie is the shallowest of all the Great Lakes and minimizing the vessel's draft is crucial for access to certain regions.

The speed allows the owner to reduce transit time between sampling locations and the weight determines where the vessel can be pulled out of the water for the winter months.”

According to Peifer, all these factors are closely related to each other and made the determining factor on the USGS’ choice of material.

“The aluminum was a big change for us. We had worked with it a bit on smaller jobs, but we had not built an entire boat from it,” Peifer said. “But we were up to the challenge of learning the ropes while we worked on such a tight turnaround.”

Design Considerations
Typically, it takes about one year to design a ship of this size and a second to fabricate it. The USGS order required Great Lakes to design and build two ships of this magnitude in just over a year.

In order to build these vessels, Peifer and other on-site engineers received three-dimensional preliminary drawings from the USGS and then turned these drawings into two-dimensional layouts in which all materials and sizes of plate are indicated on the drawings. Each part in the layout is assigned a piece number and is sent to the material provider, who then cuts the pieces and sends them back to the shipyard with a set of assembly drawings.

“We used those assembly drawings, to tack the  pieces together and weld it out from bow to stern,” says shipyard general manager, Joseph J. Craine. “Actually we do more than just weld it out. We do all of the ancillary work, as well, including electrical, piping, insulation and more. It’s a turnkey process.”

 Great Lakes Shipyard

Great Lakes Shipyard Reshaping a Welding Department
Taking on such a large-scale, aluminum-based project required the shipyard to invest in new welding equipment, notes Ryan Cooper, technical sales representative with The Lincoln Electric Company in Cleveland, who assisted the shipyard in making the transition to new equipment and consumables.

“For this kind of work, they needed to weld out of position with a solid aluminum wire (GMAW – Gas Metal Arc Welding [MIG]),” Cooper explains. “Welding on aluminum is different than welding on steel. The crew was used to welding in position with older power sources using cored wire. To get the out-of-position weld on aluminum, they needed to learn how to use a pulsing power source to get a good bead and the penetration needed for this kind of job.”

During a trial period, Lincoln Electric went head to head with a competitor for two weeks, showcasing its Power Wave® 355M with Power Feed™ 25M and the Python™ Plus Push-Pull gun combined with Lincoln Electric’s SuperGlaze® 5356 wire, the company’s most popular aluminum welding wire for the shipbuilding industry.

The Power Wave® features some of Lincoln Electric's most sophisticated welding technologies and processes combined into a single, highly efficient inverter-driven power source designed for advanced semiautomatic welding. Lincoln Electric’s Waveform Control Technology® is at the heart of Power Wave® 355M performance, enabling processes such as Pulse-On-Pulse® and Power Mode®. Precise control of process parameters permit welding on a variety of materials, including steel, stainless steel and nickel alloys, as well as the aluminum alloy Great Lakes Shipyard was required to use to meet USGS specifications. Programmable optimization of the arc for each material type, welding wire type, wire diameter and shielding gas mix delivers consistent welds time after time.

“Everyone here had been working with older equipment, and we realized the programmable Power Wave® 355M would take us to the next step,” Craine said. “It really simplified the process for our welders. We also evaluated welding wire choices. We tested eight different types of wire, and as far as production goes, the SuperGlaze® was the most productive.”

Great Lakes Shipyard

Great Lakes Shipyard

Another factor came into play in the decision making process – Training. As Craine noted, only a handful of the welding staff was certified in aluminum welding by the American Bureau of Shipping, the agency whose welding standards the shipyard follows.

“Only three or four of our 28 welders were certified to weld on aluminum,” he said. “We knew we had our work cut out for us.”

Lincoln Electric stepped in and remedied the situation with two weeks of intensive training for the Great Lakes welders.

The program, led by Cooper and a Lincoln Electric Welding School instructor Lyle Binns, consisted of both classroom lessons and hands-on welding.

“At the end of the two weeks, everyone was certified in aluminum welding. That wouldn’t have happened without Lincoln Electric’s instruction,” Craine says. “The training support was invaluable, and the Lincoln instructors were well versed in our industry.”

Great Lakes Shipyard

Great Lakes Shipyard

On the Job
Once training was complete, the fabrication crew got to work, carefully joining the two ships’ aluminum components. Actual construction began in November 2010 and is scheduled to end in August.

To keep pace with the requirements of both the materials and the job deadlines, the Great Lakes fabrication team has been working 10-hour shifts, six days a week on both of the vessels.

“Aluminum is much more difficult to work with than steel,” Craine says. “It moves around, warps, flexes. It’s definitely not as predictable as steel, and there’s less margin for error. Because it is delicate and also oxidizes quickly, you can’t grind a weld out on it like you can with steel. You have to start over with a fresh component. And, in steel fabrication, once you cut it, you can just tack it and weld it. With aluminum, you have to clean it and then weld it almost immediately after cutting.”

Great Lakes Shipyard

Great Lakes Shipyard

The combination of Lincoln Electric’s Power Wave® inverter technology and its SuperGlaze® wire has helped keep production on target, if not slightly ahead. And it has helped the team fabricate quality welds that hold up to even the most rigorous strength tests.

“The 5083 alloy has a high-tensile strength, so we’re limited with what we can use on it,” Craine says. “In the weld tests, the material can break, but the weld does not – Lincoln Electric’s technology has been a winner for us in this arena and overall on this entire job.”

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