As a safety precaution, your submarine has been supplied with outer torpedo tube doors in order to prevent flooding when loading said tubes with further weaponry / ordnance. As such is the case, the torpedo room operator ~must~ open said outer door(s) prior to attempting to launch said ordnance at unfriendly (or otherwise) targets by use of the <Q> (Queen) key. This step would be attempted after closing the interior door, of course. Cycle through the tube selection with the <W> (Whiskey) key for the forward room, and the <E> (Echo) key for the Aft room. Failure to do so, and attempts to over ride said safety interlock could potentially result in a catastrophic internal explosion, if the weapon did engage, which would not only render your submarine potentially inoperable, but would complicate attempts to surface afterwards, and make the inhaling of a gaseous atmosphere nigh on impossible...
Sorry, I'm full of it today...
![Arrgh!](images/smilies/piratey.gif)
The "Q" key opens your torpedo tube doors though, so that you can "launch". The keyboard "shortcut" to actually fire the torpedo, is press the <Ctrl> key and hold it, while you then hit the <Enter> key. In the root folder of the SH4 install, after you activate Fall of the Rising Sun Ultimate, you will find a couple of keyboard "pictures", "SH4_Q-Ref_Card_Front.jpg" and "... _Back.jpg" for further reference to what is available...