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NEWS | March 31, 2022

BOF cable clamps get an upgrade - and a patent

By Max Maxfield, PSNS & IMF Public Affairs Puget Sound Naval Shipyard & Intermediate Maintenance Facility

Puget Sound Naval Shipyard & Intermediate Maintenance Facility employee designed a clamp to protect the miles of blown optic fiber cable running throughout U.S. Navy vessels, which has been approved for shipboard use and has also been recently patented. His BOF cable clamp may eventually end up saving the U.S. Navy millions of dollars in rework as more and more BOF is used throughout naval vessels.

Brandon Rottle, at the time a supervisor with Shop 51, Marine Electricians, first had to deal with the problem of damaged BOF cables during an availability on USS Theodore Roosevelt (CVN 71) in San Diego.

“The biggest problem was the wiring saddles were falling out of the wire ways when people released the hose clamp holding all of the cables in that band,” said Rottle, currently a nuclear general foreman with Shop 67, Marine Electronics. “They would forget to put the saddles back over the BOF, and end up crushing the hollow BOF tube when they put the hose clamp back over the bundle of cables in the wire ways.”

According to Rottle, the individual lines of BOF inside the tubing are about as thick as number five pencil lead. The lines can easily be broken if the cables holding the lines are bent or crushed. When these lines are damaged, it creates a lot of work for Shop 51 and Shop 67 mechanics.

“You cannot splice BOF cable,” he said. “If you break it, you have to tear it out and re-run the entire line. And if the seven BOF lines inside that cable go to several different boxes, you have to tear each one of them out as well. It becomes this giant domino effect.”

After dealing with the headaches of damaged BOF cables, Rottle later had an epiphany while attending BOF training run by PSNS & IMF.

“The only thing we had that was approved for shipboard use was that metal saddle that would fall off,” Rottle recalled. “I was thinking, ‘Why don’t they just redesign the saddle to reduce a lot of the failures?’ I went home and thought about a new design.”

“I could not sleep one night, so I got up and drew out the basic design of a BOF clamp, with all of the dimensions, on a napkin,” he continued. “I took computer-aided drafting during my apprenticeship, so I was thinking in 3D. I next drew it up on a Computer Aided Design board, with a side view and top view, on paper.”

Rottle said his design wraps around the BOF and clamps to itself. It does not clamp to the cable.

Rottle showed his design to Jesse Matheson, the Shop 51/67 nuclear director. Matheson suggested he begin the process of getting it approved for shipboard use.

This process would include using additive manufacturing, commonly referred to as 3D printing, to create prototype BOF clamps for testing. Rottle also had to work with Naval Surface Warfare Center Dahlgren Division, who set the requirements for every repair part used aboard U.S. Navy vessels.

“Eventually (now retired) Ron Schroff, who worked in 3D printing in Shop 67 at the time, made me a 3D printer file from my (side and top view) drawings," Rottle said. "We printed one, but it was not perfect. We eventually ended up going through five different versions.”

“I did the testing for each version,” he said. “I would do fit up and take photos. I would install it on cable hangers and figure out what was working and what was not.”

Key considerations included integrating zip ties so the clamp could not fall off accidentally. It also had to be reusable. It was also designed to grip each cable in a bundle, so it would not slide down if it were installed on vertical cable.

Rottle began trying to generate awareness and interest in his design. After months of failing to make any headway in getting the “Rottle clamp” approved for shipboard use, he stopped working on it.

“I gave up and let it sit for about eight months,” he said. “That was in 2017. My boss Jesse Matheson called me in 2019 and asked me what was going on with the clamp. He told me we need to get that approved because it’s one of the best ideas for fiber he’d ever seen. I told him I was not hearing back from any of the people I needed to get it approved.”

“That’s when Mitch Van Epps, who was a Code 1010, Reactor Systems, cell manager, got pulled in,” Rottle said. “Jesse walked over to Mitch and told him he had something for him to work on. Mitch came in at prototype version four. I knew it was still a bit bulky and we wanted to trim it.”

Van Epps, currently a temporarily promoted nuclear assistant project superintendent with Code 360, the Manufacturing & Support Office, worked in process improvement at the time, had been helping get tooling made for the Shop 38, Inside Machine Shop, Primary Valve Staging Group. This effort gave him a good understanding of 3D printing, as well as experience working with other shops on innovation efforts.

“After contacting me and bringing me up to speed on what he was trying to achieve, I in turn started promoting this effort every chance I got,” Van Epps said. “Think used car salesperson when I went to a symposium meet up with the NAVSEA 05 (Naval Systems Engineering & Logistics Directorate) person who Brandon had been trying to work with on getting these looked at, and possibly approved. After that, I stayed in contact with him as well as Brandon and the Dahlgren group.”

Rottle and Van Epps continued to refine the design even further, before they were able to generate some momentum with representatives from Dahlgren they met at an innovation fair.

“After several prototypes were developed, Brandon and I ended up the following year going to Spokane for the innovation fair," Van Epps said. "We were able to talk face-to-face with the Dahlgren reps and get them to really start the approval process on what we needed to start using these aboard U.S. Navy ships.”

After that, the specifications and samples were repeatedly sent to Dahlgren. Dahlgren had various concerns over time, including the bulk, weight, and flammability of the clamp.

Rottle and Van Epps managed to reduce the mass of the clamp to an acceptable level, and addressed Dahlgren’s flammability concerns. ULTEM 1010 thermoplastic was used, which has a high melting point and produces very little smoke.

Rottle said Van Epps’ innovation background and enthusiasm level were instrumental in keeping the momentum going on the BOF clamp shipboard use approval process.

“Mitch was persistent,” Rottle said. “He was not disrespectful or rude, but he was persistent. He also knew people at NAVSEA who could help us.”

Van Epps said his enthusiasm for the project stemmed from the potential savings that could be realized by the innovation.

“When Brandon first approached me looking for help, I was all for it from the get go,” Van Epps said. “When he showed me the amount of money spent on a single project due to rework from the use of the metal saddles failing, this screamed savings.”

Rottle and Van Epps had to fine tune their final design one more time before Dahlgren and NAVSEA were satisfied, and approved the clamps for shipboard use. So far, BOF clamps have been designed to hold one, two or three BOF cables.

Once the clamp was approved for shipboard use, Rottle and Van Epps were able to get the PSNS & IMF toolmakers division to create an official shipyard drawing for the clamps, which included the additive manufacturing marks as well as an official drawing number. This drawing was used to create a commercially produced mold, so the clamps can be injection molded in the future.

Once the clamp design was finalized and approved for Navy use, Kyle Denton, PSNS & IMF digital transformation manager, worked with Rottle, Van Epps and the Naval Undersea Warfare Center Division Keyport’s Intellectual Property Counsel’s office to have the device patented. Now, the Navy’s Technology Transfer Office can share the device — for a fee — with industries outside the Navy that may be interested in using the clamp.

Ron Zmijewski, research, development, test and evaluation manager, Code 100PI, PSNS & IMF Lean Office, said PSNS & IMF is working with TechLink, which helps innovation-minded businesses and entrepreneurs identify, evaluate and license technology developed within DOD and VA labs nationwide.

“TechLink helps them with an express patent licensing process,” Zmijewski said. “We may receive royalties directly, though generally they go back to the Department or Treasury.”

According to Rottle, the next step at PSNS & IMF is to have the clamps injection molded for mass production. Injection molding them will be cheaper, faster and the product will be slightly better than 3D printing individual clamps. Until PSNS & IMF commercial mass production of the clamps ramps up, they will continue to be 3D printed, one at a time.

“I feel sorry for the toolmakers,” Rottle said. “They ended up 3D printing 600 of these once they were approved for shipboard use. If you were to go retrofit a carrier right now and replace all of the copper wires with BOF, you would need thousands of these clamps."

What started as an idea and a sketch on a napkin years ago is now a patented technology the Navy can use to save millions of dollars by preventing damage to BOF cables. While the process of refining the design and getting it approved for shipboard use was complicated and convoluted at times, Van Epps said it was well worth the effort.

“I was proud to be a part of this, and to help Brandon’s idea come to life,” Van Epps said. “It was very interesting to see what it takes to get something created in the stock system and to also get in through the patent process.”

He has advice for other would-be innovators at PSNS & IMF.

“Don’t let an idea get pushed aside,” he said. “And, don’t be discouraged with the amount of time it can take to get things going or, even worse, into actual use. There are a lot of steps and it can be disheartening when you think it’s a quick fix or a simple idea. It may seem mundane or non-value added, but it could save us time, money and resources in the future.”