Ingalls Shipbuilding sees better efficiency and quality with automated bulkhead production
In 2015, the American shipyard, Ingalls Shipbuilding, made a significant investment to modernize its shipbuilding process by working with numerous vendors, including PEMA welding for production automation. Due to the collaboration, the shipyard implemented one solution which helped automize its bulkhead production. The collaboration resulted in the shipyard seeing benefits of more efficient and flexible manufacturing.
Ingalls Shipbuilding, a division of HII, has designed. built, maintained amphibious ships, destroyers, and cutters for the U.S. Navy and the U.S. Coast Guard for nearly 85 years,
Employing more than 11,000 employees, HII’s Ingalls Shipbuilding division is the largest manufacturing employer in Mississippi and a major contributor to the economic growth of Alabama. For nearly 85 years, Ingalls has designed, built, and maintained amphibious ships, destroyers, and cutters for the U.S. Navy and the U.S. Coast Guard. The largest supplier of U.S. Navy surface combatants, Ingalls is simultaneously building four classes of ships and has pioneered the development and production of technologically advanced, highly capable ships for the surface Navy fleet for decades.
In 2014, Ingalls launched its extensive “Shipyard of the Future” initiative which involved significant investments in capacity expansion, process film,1 and access, and utilization. A year later, the collaboration between Ingalls and Pemamek began when the Finnish welding automation provider won the contract to design and engineer a new panel line. In 2017, Pemamek began its delivery and installation of a state-of-the-art plate lengthening line, designed to feed two complete modern flat-panel Iines simultaneously.
“We installed a complete panel line, including an automated PEMAhybrid laser one-side welding station and two gantries with four robots each. We also replace our existing SAW-OSW with a new integrated PEMA milling OSW,” comments Kevin Roossinck, manager of welding engineering at Ingalls Shipbuilding.
We knew Pemamek could make an impact on the distortion of manufactured bulkheads.
Kevin Roossinck, manager of welding engineering at Ingalls Shipbuilding
Previously, Ingalls manufactured bulkheads by combining mechanized line and manual work. Now, the process is automized with PEMA welding equipment.
Bigger volumes, thinner material
Bulkheads, also referred to as micro panels, are some of the most essential structural components in shipbuilding. As a major shipbuilder, Ingalls produces bulkheads with an annual volume of 2,200 or about 40 per week. The shipyard expects the annual production volume to increase and material thicknesses to decrease, so the timing to automize the process was optimal to meet pending requirements.
“Since the results from our previous panel line project were so positive, we saw a window of opportunity to introduce automated processes to bulkhead manufacturing and reap similar benefits of efficiency, quality, and reduced distortion. When we looked to the future, the required volume was expected to exceed our capacity, hence we needed to add to those existing capabilities,” describes Roossinck.
Bulkheads that Ingalls manufactures vary greatly in size. An average structure can be 9 feet wide x 15-20 feet long but, on occasion, they can be as long as 50-60 feet. Previously, the shipyard had a mechanized process, beginning with a submerged arc welding seamer and followed by two fixed fillet welders.
Roossinck continues:
“We had a mechanized welding line, but everything else needed to be performed manually, which did not meet our future needs. With bulkheads, the material is usually thinner, and the thinner the material, the more significant the distortion.”
Supported by the positive results of the previous project, the shipyard placed an order in 2017 for another installment of PEMA welding equipment to modernize its bulkhead production.
“Based on the experience we had with the PEMA laser-hybrid panel line, we were very pleased with the results from the distortion standpoint. We knew Pemamek’s equipment and expertise could make an impact on the distortion of manufactured bulkheads,” tells Roossinck.
When we looked to the future, the required volume was expected to exceed our capacity, hence we needed to add to those existing capabilities.
Kevin Roossinck, manager of welding engineering at Ingalls Shipbuilding
Shift to automated fitting and handling
A bottleneck in Ingalls’ production was bulkhead fitting and handling. To tackle this challenge and reinforce the shipyard’s production capacity, Pemamek delivered a state-of-the-art welding automation line designed specifically for efficient bulkhead production. The engineered line included one side welding station with integrated milling (PEMA M&OSW LHAW) and special magnetic arm plate feeding portals, stiffener assembly manipulator (PEMA SAM), web mounting portal (PEMA WMP), and two robot welding portals (PEMA VRWP-R2). The line is enhanced with high-technology process management and programming software, such as PEMA Line Manager and PEMA WeldControl 200.
“The previous line did not have any fitting aids, and thus, everything was done manually. Now with the new PEMA bulkhead line, we don’t need to use overhead cranes to place profiles because we have the stiffener assembly manipulator to handle the profile and put it in place,” describes Roossinck.
Before, stiffening members were forced to the bulkhead deck manually, causing damage to the material and requiring repairs. Now, the line has a pressing beam in the solution, with magnets on either side in case the beam is not enough. Another significant technical advancement is the change from SAW welding to laser-hybrid. This, Roossinck considers, is having an impact on gaining better efficiency and quality:
“Previously, we had SAW welding, which is a good process, but better suited for thick materials because of its high deposition rate and heat input. With thin materials, this can cause distortion. Now, this is replaced with a laser-hybrid, which enables high travel speeds, narrow weld zones, and low heat input, which translates to reduced distortion. On the fitting side, there are no longer any weld tacks that need to be removed due to the new fitting processes,” tells Roossinck.
The line includes a specially engineered system to facilitate handling and fitting, which minimizes damage to the material.
The line is enhanced with high-technology process management and programming software, such as PEMA Line Manager and PEMA WeldControl 200.
Welding 65 inches per minute
When it comes to production improvements, Ingalls has realized benefits, including reduced damage and subsequent repair due to eliminating the need for manual fitting aids thanks to the special pressing beam and magnet system. Furthermore, another improvement is the increased travel speed of the seam welding process, which has resulted in decreased distortion.
“Currently, we weld about 65 inches per minute, whereas the old process was about 15 inches per minute. Previously, we welded on both sides of the plate but now, thanks to the new welding process, we only need to weld one side. This makes the production speed three or four times faster,” describes Roossinck.
Finally, Roossinck identifies the benefits of intelligent robot welding. According to him, it increases manufacturing performance, adaptivity, and flexibility. Roossinck summarizes:
“You can load up a whole work area, scan it, and once it starts welding you program the rest of it. As a result, you can do a lot in a little time. Robots are much more efficient than fixed automation.”
To Ingalls, incorporating robot welding into production has boosted manufacturing performance, adaptivity, and flexibility.s leo.
