Technology and Operations
This forum is for discussing technological & operational matters pertaining to U-boats.
Re: Torpedo Launching
Posted by:
ROBERT M.
()
Date: October 29, 2003 05:01AM
Ken:
You wrote: "Perhaps there were some stock or parts left over from WWI
at the beginning of WWII."
One can't just install a single-bladed screw to any torpedo. The G7e
had a gearbox in the after end of the afterbody of the torpedo, that changed the output of the electric propulsion motor's shaft to a contra-rotating pair of two-bladed propellors.
I can't speak for the G7a driive train but it seems that the Germans may
have used the same design as the G7e for the contra-rotating screws.
If one uses only a single screw for propulsion in an any torpedo design, changes have to be made to the four tail stabilizing "fins". This
is accomplished by skewing all four fins a few degrees to counter the torque created by a single screw.
The U.S. Navy's MK 24, MK MK 27, Mk 28, MK 29, MK 32, and MK 34
torpedoes had single-screw electrical propulsion, with skewed control surfaces.
The reason this was done, is tthat these units were originally copied from the G7e, which had that noisy gearbox, so, by installing a direct-drive single-bladed screw, less "self-noise" resulted.
Perhaps some of the later German passive-acoustic variants used single-blade screws.......
You wrote: "Perhaps there were some stock or parts left over from WWI
at the beginning of WWII."
One can't just install a single-bladed screw to any torpedo. The G7e
had a gearbox in the after end of the afterbody of the torpedo, that changed the output of the electric propulsion motor's shaft to a contra-rotating pair of two-bladed propellors.
I can't speak for the G7a driive train but it seems that the Germans may
have used the same design as the G7e for the contra-rotating screws.
If one uses only a single screw for propulsion in an any torpedo design, changes have to be made to the four tail stabilizing "fins". This
is accomplished by skewing all four fins a few degrees to counter the torque created by a single screw.
The U.S. Navy's MK 24, MK MK 27, Mk 28, MK 29, MK 32, and MK 34
torpedoes had single-screw electrical propulsion, with skewed control surfaces.
The reason this was done, is tthat these units were originally copied from the G7e, which had that noisy gearbox, so, by installing a direct-drive single-bladed screw, less "self-noise" resulted.
Perhaps some of the later German passive-acoustic variants used single-blade screws.......
