Technology and Operations
This forum is for discussing technological & operational matters pertaining to U-boats.
Re: Torpedo Launching
Posted by:
Ken Dunn
()
Date: October 30, 2003 08:05PM
Hi Kurt,
I really like the comparison between popping the hatch to get out and jumping through it to get back in. I wish I had thought of it. It’s all about those men risking personal injury in order to provide maximum protection for their boat.
As to operator error - perhaps some commanders were just more willing to pop that hatch and take their chances than others or perhaps there was something in the design, manufacture or fit of the hatches on specific boats that made it difficult to just pop the hatch enough to bleed off the excess pressure.
I am still going crazy wondering how the pressure differential got great enough to blow a man out of the hatch. Torpedo firing is certainly one way to raise the pressure but is it enough to raise it that much? I wish I knew how to do the calculations to figure out how many torpedoed would have to be fired to generate that much pressure, assuming that is what did it. If it was tied directly to the number of torpedoes fired I would think that experienced commanders would have known that opening the hatch would be more dangerous than normal once they had fired a certain number of torpedoes. They fired a lot of them during training and should have encountered this problem early in their careers.
There would be quite a bit of volume in the six 7-meter + long torpedo tubes in a type IX and if it were fully provisioned the internal volume of the boat would be considerably reduced so perhaps torpedo firing alone could have done it. I guess it could have even been worse with 5 torpedo tubes in a Type VII as the amount of provisions would have been pretty close and the Type VII was smaller than the Type IX.
Surely there has to be an engineer type out there that could make a stab at the calculations. Knowing this would tell us how often these conditions existed. If they were quirt rare (say because more than 6 torpedoes would have to be fired etc.) that would perhaps point to these being accidents that no one was prepared for. If on the other hand that much pressure existed after firing only a few torpedoes it would be a common occurrence that all of the commanders should have been prepared for and that most were able to deal with.
It might have taken a combination of things like firing several torpedoes and also staying submerged for an extended period of time (with the other things that raised the pressure in the boat taking place for longer than normal) due to being constantly attacked etc. Something like that may not have been encountered during training or even other combat operations and the commanders wouldn’t have necessarily been prepared for it when they finally got to open the hatch.
During training these men were graded on how long it took them to get in and out of that hatch and this activity was thought of as being critical to their survival.
Regards,
Ken Dunn
I really like the comparison between popping the hatch to get out and jumping through it to get back in. I wish I had thought of it. It’s all about those men risking personal injury in order to provide maximum protection for their boat.
As to operator error - perhaps some commanders were just more willing to pop that hatch and take their chances than others or perhaps there was something in the design, manufacture or fit of the hatches on specific boats that made it difficult to just pop the hatch enough to bleed off the excess pressure.
I am still going crazy wondering how the pressure differential got great enough to blow a man out of the hatch. Torpedo firing is certainly one way to raise the pressure but is it enough to raise it that much? I wish I knew how to do the calculations to figure out how many torpedoed would have to be fired to generate that much pressure, assuming that is what did it. If it was tied directly to the number of torpedoes fired I would think that experienced commanders would have known that opening the hatch would be more dangerous than normal once they had fired a certain number of torpedoes. They fired a lot of them during training and should have encountered this problem early in their careers.
There would be quite a bit of volume in the six 7-meter + long torpedo tubes in a type IX and if it were fully provisioned the internal volume of the boat would be considerably reduced so perhaps torpedo firing alone could have done it. I guess it could have even been worse with 5 torpedo tubes in a Type VII as the amount of provisions would have been pretty close and the Type VII was smaller than the Type IX.
Surely there has to be an engineer type out there that could make a stab at the calculations. Knowing this would tell us how often these conditions existed. If they were quirt rare (say because more than 6 torpedoes would have to be fired etc.) that would perhaps point to these being accidents that no one was prepared for. If on the other hand that much pressure existed after firing only a few torpedoes it would be a common occurrence that all of the commanders should have been prepared for and that most were able to deal with.
It might have taken a combination of things like firing several torpedoes and also staying submerged for an extended period of time (with the other things that raised the pressure in the boat taking place for longer than normal) due to being constantly attacked etc. Something like that may not have been encountered during training or even other combat operations and the commanders wouldn’t have necessarily been prepared for it when they finally got to open the hatch.
During training these men were graded on how long it took them to get in and out of that hatch and this activity was thought of as being critical to their survival.
Regards,
Ken Dunn
