NORFOLK NAVAL SHIPYARD, Portsmouth, Va. —
Multiple shops came together to manufacture and deliver a feeler gear to the fleet in support of the USS Wyoming (SSBN-742).
“Shop 31 (Inside Machinists) was tasked to make the feeler gear and our machinists hit the ground running to cut the gear out of plate steel, manufacture the fixture, and cut the teeth,” said Section 400 Supervisor Jeff Pritchard. “It takes a lot of coordination to get this type of work completed and it’s a job that we haven’t tackled in the shipyard for close to ten years. But we were ready to produce a first-time quality product.”
The production began with Section 100 in Shop 31, the vertical turret lathe producing the fixture and blank for the gear. They waterjetted the material out of the plate and then the milling machine would be used to drill holes as needed. The next step involved the gear hobbing machine, which would be used to cut more than 500 teeth into this large gear.
“This is work that hasn’t been done in years and it was a first for me as I’ve never done work on a gear this size before,” said Machinist Dave Lewis who is known as the ‘gear guy’ in the shop. “I’m currently the only one trained at the shipyard to run these gear cutting machines and it can almost be qualified as a lost art as we rarely handle that kind of work here anymore. So when this job came up I was excited to jump into it and get it done.”
Third year apprentice Kim Compton had heard about a possible chance to work with the gear cutting machines and she jumped at the opportunity, joining Lewis to work alongside him and learn the ins and outs of the gear cutting trade.
“I joined the apprenticeship program to help out and get my hands dirty in support of the shipyard,” said Compton. “I really want to learn and do whatever I can to help. And working with these machines and with Lewis was a perfect opportunity to do just that. It was a huge team effort to get the job done and being able to be part of that was very amazing to me. We’re making differences and it’s a great feeling seeing your hard work paying off.”
“Kim’s put forth tremendous effort and has shown so much drive in everything she’s done,” said Lewis. “Seeing her drive and hitting the ground running with everything I’ve been teaching her shows how dedicated and hardworking she is. And being able to pass on that knowledge I gained years ago and keeping the art of gear cutting alive is a big win for me.”
Lewis and Compton worked together on the gear hobbing machine to cut the teeth of the gears and their work was just about completed when a hurdle crossed their path – the motor of the machine had locked up and burnt out from age.
“This machine hadn’t been run in close to ten years so and its age had caught up to it,” said Pritchard. “The machine itself was from the 1930s and was used in World War II. Being such an older piece of equipment, we were worried that we wouldn’t be able to get the parts necessary to fix it and get the work completed.”
Prichard and his director quickly reached out to the Temporary Facilities and Equipment Division (Code 900F) who stepped up to the plate and brought a team together to fix the motor for the machine.
Tool Room Mechanics (Shop 06) removed the motor and discovered the drive end bearing overheated which severely damaged the existing Babbitt bearing. The Electricians (Shop 51) Motor Section ensured there were no electrical issues, then cleaned, prepped for assembly, and routed to the machinist team for necessary mechanical repairs.
“Once the Electrical Machinists (Shop 31E) received the parts, myself and senior machinist Dennis Boyd realized the task we were up against,” said Shop 31E Work Leader Keith Garza. “We used our prior experience from re-working several different motors from this previous era with successfully overhauling several bridge crane motors with the same bearing configuration over 10 years ago. The knowledge and lessons learned from those past experiences were used to ensure a cost effective repair of the motor and our team was able to do a timely overhaul.”
Shop 31E diagnosed and developed a plan of attack. The senior machinists would oversee the younger guys doing the work. X31E machinist Zack Fraser and Ethan Hancock jumped at the opportunity to repair the damaged parts. The rotor shaft was set up in the machine to remove the grooves on the bearing journal on the drive end of the motor. The drive end bearing was set up and machined to remove the damaged Babbitt sleeve. Fraser and Hancock then manufactured the new sleeve out of bearing bronze to replace the Babbitt. The sleeve was then pressed into the existing sleeve. Then the newly sleeved bearing was set up and machined to tight tolerances to achieve the proper bearing clearances. Then they manufactured a new oiling ring. The oil reservoir gaskets were replaced at both ends of the motor to prevent any leaking around the shaft. Once everything was completed, the motor was reassembled to specifications and was ready for reinstallation.
“This group went above and beyond to assist Team NNSY with getting the job done right the first time,” said Garza. “Everyone worked in a timely and safe manner to achieve a first time quality product and to assist their fellow shipyard workers. This job has been a true testament to team work and how we all play a part in servicing the fleet.”
Industrial Engineering Branch (Code 983) Engineering Technician Dave Watkins added, “Even when a roadblock stood in the way, everyone looked for solutions on how to get the work done. The teamwork shown by Shop 31, 31E, 51, 06, and Code 900F has been tremendous and because of their efforts we were able to get the feeler gear completed for the Wyoming project fast and ready to go. Great work to everyone involved!”