I was watching the old classic The Enemy Below with Robert Mitchum and Curt Jurgens. In the movie, as in every submarine movie, during a depth charging bunch of pipes and seals spring a leak. The crew rushes to the nearest valve and shut it off before the leak.

Here is my question. If they shut the valve to stop the leak, wouldn’t they cut off the supply of oil/water/lubricant in the pipe to whatever piece of machinery needed the fluid? Are their multiple pipes so that if they shut off some of the lines that there is still something getting through?

Very perceptive question.. the answer is -yes and no. Submarines have redundant systems and if you are getting depth charged you dont really care if the head is working - cause you probably already used your pants! - so if the system is not critical to propulsion or depth control - you can fix it later- also there's an element of hollywood here as well. the first rule of thumb on damage control is put out fires and the second is to control flooding. In the movie (one of the best) the germans are trying depratly to escape an american destroyer so everything else is secondary.