Compressed Air Gauge Broken?

[ryanglavin]

Originally Posted by vergol

A question related to this topic:

I've noticed that my compressed air reserves diminish after torpedo attacks. Is compressed air used to flood/empty the tubes as well?

In american fleet boats, (probably the same for U-boats), they would first flood the tubes, by opening them. When they shot the torpedo, to replace the displaced weight, they shut the tubes immediately, then filled the tubes with compressed air to outset the lost weight from firing the torpedoes. And torpedoes weighed ALOT.

[vergol]

Seems logical. They should put that in the manual. Thanks guys.

[FrankDiver]

Originally Posted by ryanglavin

...then filled the tubes with compressed air to outset the lost weight from firing the torpedoes.

Hmmm... That doesn't make sense to me. Blowing the water out of a torpedo tube would increase the lift of the sub even more, in addition to the same effect caused by the lost torpedo weight.

IMO after firing a torpedo, the only way to keep neutral buoyancy is to partially flood the ballast tanks, which is equivalent to lowering the total volume of the system.

[Sailor Steve]

They didn't fill the tubes with compressed air to offset the weight of the torpedo. Air weighs a lot less than water, so using air to offset the weight wouldn't work. Compressed air from a special tank was used to fire the torpedo. They then shut the outer door and used the compressed air to force the water out of the tube so they could open the inner door to reload it.
http://www.maritime.org/fleetsub/tubes/chap9.htm