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Small-Scale Question Sunday for June 18, 2023

Do you have a dumb question that you're kind of embarrassed to ask in the main thread? Is there something you're just not sure about?

This is your opportunity to ask questions. No question too simple or too silly.

Culture war topics are accepted, and proposals for a better intro post are appreciated.

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The only thing inaccurate about the scene in Down Periscope where the guy stretches a string across the engine room, and it sags as they dive? He states that you wouldn't see it on a nuclear sub, which is wrong. I'm pretty sure every submarine is designed to compress under water pressure, and combat subs don't dive nearly as deep as exploratory subs.

Yeah -- CF is bad in compression generally and (in my non-materials engineer opinion) probably especially bad when it's evenly compressed around the whole surface. (and then decompressed whenever it surfaces, of course)

I could imagine ways to overcome this (laying up the fibre under pressure?) but it seems very process dependent -- "Trust in Steel" OTOH is time-honoured.

Is there even any downside to using a giant steel ball for a submarine pressure hull? You're not paying to shoot it into space, you literally just want it to sink. I know the Soviets used titanium, but they did a lot of crazy stuff.

I mean you do kind of want it to be able to float at times rather than just staying on the bottom forever. But yeah, I think steel is pretty good. Corrosion would be a thing to watch out for I guess, but there are pretty well known ways of doing that.