Thanks nerd.
I'm quite familiar with " Archi's" principle. :>) In another life, I was involved with screw pumps, many of which were installed in our nuke subs. We built many of them to operate at 3000 PSI. I left the company in 1973. As far as I know, they might still use those same or similar pumps. At that time, there weren't any centrifugal or diaphragm pumps that could handle that pressure.
This might interest you. During one of the tests ( for the diving plane hydraulic system ), a quarter inch tube connector blew. The fluid hit one of my men in the head and knocked him down. He was OK after a bit of "squirrely" behavior. We took him to the hospital for a checkup. They said he didn't have a concussion but they did say, if he had been hit in the temple, things could have been worse. He sported a significant bruise for quite a while.
The "Thresher" had our pumps. I was glad the "fault" was never tied to a failure of our product. The consensus was the boat lost propulsion at a time when it was in negative buoyancy. You need the diving planes and forward propulsion to "fly" upward till you reach a depth where blowing the ballast will be effective.
The company I worked for was DeLaval.
