Shop 31 employees custom build portable milling machine to support work on submarine hatches

Shop 31 employees custom build portable milling machine to support work on submarine hatches

By Max Maxfield, PSNS & IMF Public Affairs

BREMERTON, Wash. -

The expert toolmakers in Shop 31, Inside Machinist, recently answered the call to quickly design, build, test and deploy a portable three-axis Logistical Escape Trunk Lug radial milling machine for some emergent work at Puget Sound Naval Shipyard & Intermediate Maintenance Facility.

The machine is used to help ensure the tolerances on submarine hatches remain very precise, even after they've been worked on dozens of times over the years.

According to Thomas Slater, toolmaker/tool & cutter grinder general foreman, Shop 31, Inside Machinist, the newly designed machine cuts the top and the bottom of the locking lugs after they have been welded. The metal on the lugs wears down over time, and these surfaces eventually require precision machining of the weld area to bring all surfaces back to original specifications.

"The original scope for the machine was to be able to do straight line milling on both surfaces of the lugs," Slater said. "They later asked if the toolmakers could design and make another milling machine that would cut on an arc to match the eight-foot diameter of the Logistical Escape Trunk, to save time on hand work. It took us seven weeks to design and build the first machine, and only three weeks to adjust the design and make the second milling machine."

While some people may think of custom wrenches, hammers or pliers when they think of toolmakers, Slater said the expertise and ingenuity of the Shop 31 Toolmakers allow them to create completely custom power tools, hand tools and machines to fill specific needs from the various customers throughout PSNS & IMF and the Navy.

"The toolmakers here research, design, build, test and train anyone requiring custom portable machining," Slater said. "We work with multiple engineering codes to manufacture one-off tools and future corporate tooling. We build tooling for both nuclear and non-nuclear applications. We have designed and built everything from large machines like the catapult rail drilling machine, to one-inch valve packing removal tools."

In the case of the portable milling machine, the customer needed the machine quickly.

"Soon after we started the research and design for this tooling package, the project invoked Emergent Work Protocol, which means they needed this tooling completed as soon as possible," said Slater. "This means as soon as a part for the assembly is identified for purchase or has a completed drawing for manufacture, it is processed urgently. The parts of this tooling were manufactured non-stop across all three shifts, until completion."

Even though the team designed and built the machine as quickly as possible, they worked closely with their "customer" and their regular collaborators to ensure the final product was perfectly suited to the job it was needed for.

"We always work with our customers to ensure the scope of work to be done is clearly defined and that we are meeting their needs," Slater said. "In this case, the customer was the USS Pennsylvania (SSBN 735) project team. We worked closely with Shop 38 [Marine Machinery Mechanic], Code 260 [Fluid & Mechanical Engineering & Planning], and Code 106 [Environment, Safety and Health Programs] to ensure safety was built into the tooling."

"Their input and expertise are some of the key elements for success and safety of the finish product," Slater continued. "We design and build machines and tooling from the information provided by our customers, with engineering expertise and Code 106 guidance."

Like many of the tools and machines Shop 31 makes, this device is a combination of custom-designed and custom-built components, mixed with commercially available components. Integrating proven technologies and components into a design can drastically reduce the time needed to create a custom machine.

Slater said the main parts of the this machine include clamping blocks, a precision up/down, (Z axis), tool slide, a precision left/right, (X & Y axis), tool slide, and endmill cutter precision drive head, in-house made endmills, an electric motor and a motor controller with a programmable touch screen portable monitor. The machine is also powered by a common wall socket, for maximum flexibility.

If other Navy shipyards need to perform the same kind of work on an Ohio-class submarine, the pros at Shop 31 here can share the one-of-a-kind design with them, or the PSNS & IMF-built machine could be shipped to them.

"We have supported tooling requests from all the public shipyards in the past," said Slater. "The PSNS & IMF Shop 31 Toolmakers and Tool & Cutter Grinders excel at coming up with inventive solutions for the machining needs of our customers. We are the largest and most experienced toolmaker shop in the Navy and the only Tool & Cutter Grinder shop in the Navy."

"If your command needs assistance with a particular problem that requires a precision portable machine or related tool, our experienced toolmakers are available to assist you with one-of-a-kind tooling to solve your problem," Slater continued. "By using years of experience manufacturing portable machines and tools, Puget Sound Naval Shipyard Toolmakers have developed the reputation as the best problem solvers to turn to for assistance in producing this type of tooling.