A customer located in Pecos County, TX tasked GSM Industrial with fabricating two identical wind turbine tower top sections. The original wind towers were damaged and replacement sections were purchased in order to get the generators making green power again. This process included forming, welding, testing, and painting both of the tower sections. Each tower section started with plate steel which had to be cut, beveled, rolled, and fit up with oversight from our quality department to ensure the joint preparation was in accordance with our approved Sub-arc (SAW) procedures. GSM performed Ultrasonic Testing on roughly 30% of all the tower seam welds. Large machined flanges (one more than 3.5” thick) were welded in place and finally, we maneuvered each tower to the back of the GSM shop to load them into the blast and paint booths for finishing.
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This was the largest project to date that GSM Industrial planned to weld using our new Sub-arc welder which is mounted to a column and boom manipulator. The towers were due on site within 3 months of receiving the purchase order. Our certified welders faced a problem when it became clear that the sequence of the build process we formerly used to manually fit and weld similar towers would not work well for the Sub-arc machine.
In order to overcome this challenge, we pulled our team off the project and focused on developing a process that would work well with the Sub-arc machine. In the past, we welded the horizontal seams of each cylinder after fitting up each 10’ cylinder section to one another. The new process meant fully welding the horizontal seams and then putting the cylinder “can” back on our heavy plate roll to insure roundness was in tolerance. This made for faster and more accurate fit up of “can to can” sections. Once fit up, the circumferential seams were completed on the sub arc.
The developed process worked well and we finished the project with minimal defects after UT testing.
GSM Industrial cut, rolled, and welded over 26 tons of steel plate to make two identical 91″ diameter x 75′ tall tower sections. These were just the top part of 157 feet tall towers in the field. The plate thickness used to build the towers, ranged from 5/16″ thick to ½” thick and was ideal for our Sub-arc welder and the SAW procedure. After some initial setbacks from re-designing the process, we improved our efficiency with very few defects from the automated welding process.