Cable Penetrator Potting Project
Hefring Engineering
One of my primary projects at Hefring Engineering was to develop a process for potting cable penetrators. To allow cables to pass through the vehicle’s hull without leaking, they are potted into cable penetrators, forming an assembly that can withstand the surrounding water pressure. This was a solo project.
I began by researching potting material options. After selecting a few to try, I ran preliminary tests on cable jacket adhesion and vacuum degassing. I eliminated a few materials, designed a potting jig, and began potting samples. I made several potted penetrators with different compounds and wire sealing methods, refining the process as I progressed.
Once I made these samples, I had to test them. I designed a small aluminum pressure chamber that mimicked the glider-penetrator interface and enabled me to easily test potted penetrators in-house. After verifying the design with FEA and hand-calcs, I generated the drawings for the machined parts. I developed and documented a safe test procedure and setup, and assembled the fixture and fittings.
The fixture was effective, and I was able to test many potted penetrators and to iteratively improve the potting process. By the end of the co-op, I had a properly sealed cable penetrator capable of handling 40% over the design pressure.
I really enjoyed the balance of research, design, and development in this project. Though I began with no knowledge of potting, and was able to deliver a sealed penetrator, a potting process, and a test fixture for future penetrators.