Work Smarter, Not Harder: Norfolk Naval Shipyard Improves Welding Process for Carrier Reboilers

Photo By Shelby West | Structural Group (Code 920) Welder Diamond Lee welding outside the reboiler.  

PORTSMOUTH, VA, UNITED STATES

12.09.2020

Story by Hannah Bondoc 

Norfolk Naval Shipyard

Taking a shower, washing clothes, and cooking meals are all basic human needs that the reboiler of a ship helps with. Located in the shaft alley, its purpose is to provide hotel services including heating steam, hot water, lube oil heating and galley steam. After many years however, it eventually wears out and needs to be repaired, but such a fix requires a substantial amount of effort. Structural Group (Code 920) Surface Craft Director Jeff Griffin and his staff were tasked with welding two reboiler heads, one on USS Dwight D. Eisenhower (CVN 69) and one on USS George H. W. Bush (CVN 77). Together they not only came up with a way to finish the job faster, but also a method that was easier on the group’s welders.

Like sewing two pieces of cloth together, his crew traditionally welded each head to a shell by welding the inside and the outside of the shell together—but Griffin did not think this method was most efficient. “The welder would eventually become fatigued and have a higher risk of heat stress when welding on the internal weld, and a higher probability for damage to the tubes,” Griffin explained. “The process of welding the internal side usually takes 24 hours for five to ten days (depending on the welder) to complete before moving to the outside. The entire process done in this fashion would take 24 hours for 25-45 days depending on the final tests and repair needed.”

With these challenges in mind, Griffin decided that there had to be a better way. “As the Trades Manager on this project, I was and still am a big advocate for thinking outside the box and using innovation,” he said. “So on the USS Harry S. Truman (CVN 75) I decided, after running the idea past Welding Engineering Division (Code 138), to change the way we weld the shells to heads.”

After a challenging amount of preparation to do the job, there were two main lessons learned: firstly, that by using heat induction instead of the heater bars to maintain the needed heat to weld, they could keep a more constant temperature managed by a computer and not a controller. This kept the temperatures from going over 200 degrees with the welder on the inside of the reboiler.

The second lesson was that by welding the little bevel inside the big bevel, the welders no longer had to stay in a cramped position as long to finish the job. They effectively cut down the time the welders spent working inside the bevel from 10 to 12 days, down to one to two days. Moreover, they were able to pass testing on the first try.

Needless to say, Griffin confirmed that he could not have pulled off such an experimental welding job without his crew. “I had the same group of welders welding the heads to shells all the way up to CVN 77,” Griffin said. “We built a team of guys who had the same goal to achieve what no one else have.” These welders included Noah Claytor, Tyler Deans, Jarett Thompson, and Diamond Lee. “These welders embraced the out-of-the-box thinking and ran with it,” Griffin added.

By taking on this initiative, the crew displayed its commitment to the shipyard’s C.O.R.E. values. Highlighting a dedication to NNSY’s welders, this endeavor reduced the amount of time and stress they go through for similar welds. As Griffin said, “Our people are our most important asset, so we have to take care of them if we want to get those ships out on time.”

• Date Taken: 12.09.2020
• Date Posted: 12.09.2020 15:00
• Story ID: 384574
• Location: PORTSMOUTH, VA, US