I misunderstood your post, so we are in agreement. Thanks.

Simple answer: The torpedoes were fired using a different compressed air system than the one that blew the ballast tanks. Maybe. :doh:

IIRC, there were compressed air tanks located in the forward torpedo room. A large diaphram with the same dimensions as the tube was placed behind the torpedo after it was loaded into the torpedo tube. It was the compressed air pushing on the diaphram which resulted in the torpedo being pushed forward and out of the tube. The diaphram could only travel a certain distance within the tube before it came to a stop. The diaphram was removed from the tube and then another torpedo was loaded and process repeated.

look at the movie das boot gibralta dive to aviod aircraft emergancy blow ((not suppose to dive without cpt)) than a short steam south dive again stuck planes blow tanks than just enough for 1 more blast of course this is a movie and under emergancy so 3 emengancy blows is about it which is about right ingame :arrgh!: just the normal surfacing proceedures should be looked into as far as how much air was used --no biggie just some thoughts on this lovely day:rock:

How about the compressed air used for propelling the torpedos to target?
Would that air be pre-loaded in harbour, or something filled-up onboard?

As discussed above in some length, no compressed air was used for normal surfacing.

Again, I can only refer to the US system. It looks like pumps could recharge the whole system anytime the sub was surfaced. I assum that u-boats could recharge the system using the schnorkel, as it also drew in air for the diesels and the crew's breathing air.
http://www.maritime.org/fleetsub/chap11.htm#11C

IIRC, no German topredo ran on compressed air. The G7e was electric and ran on batteries. The G7a was steam driven and ran on combustion of fuel.

As discussed above, compressed air was used to eject the torpedo from the tube.

I have been feverishly looking through my reference books to no avail thus far, but IIRC there was a separate standalone compressed air reservoir for the expelation of German torpedoes :hmm:

Expelation?

"You keep using that word. I don't think it means what you think it means.":rotfl:

No, your right, the correct spelling is expilation...which is also the wrong word :damn:

Feck it!!...... I meant the firing of the torp out of the tube :oops:



http://imgcash3.imageshack.us/img412...uplargeon1.gif

Maybe 'expelling'.:sunny:

I knew what you meant...I just have to keep running up the post count.:rotfl:

IIRC, there was a main air compression unit located in one of the engine rooms. I do recall seeing a diagram of a Type VII which showed compressed air canisters in the forward torpedo room. They would have needed an air compressor to recharge them and I don't think there was one in the forwrd torpedo room; so they may have been feed from the main compressor in the stern of the boat.

Also, I just read that there was compressed air in the G7a torpedo to help with the combustion. Maybe, the air canisters that I believe I saw on the diagram were used to charge up the G7a torpedos and the main compressed air system was used to launch torpedos.

However, we might be beating a dead horse by now. There are so many technical aspects in the boat that historians only slightly discribe, most they gloss over, in fact. So, we'll never know all the facts on the topics that we talk about.

I searched some more info about this; Steam for torpedo propulsion is also produced by heating compressed air, so it's a possible use. Not sure if they needed topping off, or were only prefilled. It wouldn't be much air in any case I suspect.

wiki says 'compressed gas': http://en.wikipedia.org/wiki/G7a_torpedo

The japanese used compressed oxygene, with compressors generating it installed on the destroyers (based on german compressor tech), from what I understand in this link: http://inet.museum.kyoto-u.ac.jp/con...oNAKAHARA.html

bernard ? :hmm: human "gas" ? :hmm: