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Q & A: Rusty Submarines

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Most recent answer: 10/22/2007
Q:
Do submarines rust? If not, what are they made of that doesnt allow them to rust? If they do, can u send a website or more information to read about the process and prevention of rusting on Submarines?
- Meagan
WPHS, Alabama
A:
Sure, submarines get rusty.

Just like any other steel-hulled ship, a submarine will rust. There are lots of ways of preventing rust, and the more money you have to build a high-quality submarine or other boat, the more you can do to prolong its life.

Actually, I must mention that not all submarines are made of steel. Small pleasure craft not designed to go very deep may be made of fiberglass -- these offer a fun alternative to scuba diving for viewing fish but aren't good for much else. The steel parts on them may get rusty, but not the fiberglass.

You can paint a submarine to help prevent rust -- keep the water away from the steel and you can slow down or stop the rust. You can make the submarine out of alloys that don't rust as easily. There are strength and cost tradeoffs involved. You might want to make a submarine out of stainless steel if it were cheap enough and strong enough (it might be strong enough, I don't know), but stainless steel is really expensive.

We've already answered questions about attaching magnesium bars to the hull, in electrical contact. The magnesium oxidizes instead of the hull (it's not perfect but helps slow down the rusting process).

Tom

(published on 10/22/2007)

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