Hi Becks,

I find your question interesting... I am no U-Boat expert, just a studnet of history and engineering. Don't take my answer as gospel; here goes....

Given: 1 Atmosphere (14.6 Lbs/sq in.) at every 10 meters.

If the U-boat is at 280 M depth, then the external pressure would be 28 Atm. The Type VIIc U-boat used low pressure air to launch the torpedo by forcing a steel plate outward to push the torpedo out of the tube.

The high pressure air is 205 Atm, but the low pressure air in a Type VIIc is 12 Atm. The Type VIIc used low pressure air to launch the torpedoes. Therefore, I don't believe the launching air pressure (12 Atm) could over come the external pressure at 280 Meters (28 Atm).

I don't believe the torpedo tube Breech door was designed to withstand that kind back pressure. I think the torpedo tube Muzzle door could be opened because the tube could be flooded before the door is opened. So, the equalized pressure should allow it to be opened.

Even if a torpedo could be launched at a lesser depth, you would not loose much weight because after the launch the tube is full of water. The muzzle door is closed, The tube is drained and the sea water goes into a internal storage tank. Then the breech door can be opened to load another torpedo. The net weight loss would be darn little....

Hope this helps.

Regards,
Don_

"A man's got to know his limitations..."
Harry Callahan, SFPD