If you've got the time reading the following will help you in your struggles to cope with SH4 and it's issues...
Direct to the question is the following excerpt
The afterbodies of Mark 14 and 15 torpedoes and modifications thereof, are tested to 135 lbs. per square inch. It is safe to fire these torpedoes at a depth of 180 feet measured to the keel with a tube pressure of 135 lbs. per square inch. This gives an effective ejection pressure of 40 lbs. per square inch. In S-class submarines, when firing below periscope depth, to insure necessary ejection velocity of the torpedo, two impulse tanks must be cross connected. It is believed that our present torpedoes will perform satisfactorily when subjected to pressures slightly in excess of the test pressure. However, it is recommended that these test pressures be not exceeded unless it is absolutely necessary to do so. When firing below periscope depth, be especially mindful of the possibility of flooding the torpedo afterbody if the tube outer door is left in the open position for too long a period of time
The doctrine set out includes many does and don't that the individual skipper can operate by or not but at least you'll have an understanding of the comtemprary issues of the time....
Enjoy
http://www.subsowespac.org/blogs/the...2006_005.shtml
So outer doors were opened ahead of firing with the risk factor of torpedo flooding occuring with time exposure...
