Trying To ID This British Torpedo Gyroscope

[apfsds]

I recently added this beautiful torpedo gyroscope to my gyro collection and am hoping someone may be able to ID it. I believe it to be British based on the attached photograph of what I was told is the gyro assembly from a British MK20 Torpedo. The one I just added is extremely similar but obviously not the same.


PICS OF THE BRITISH MK20 TORPEDO & GYRO ASSEMBLY



PICS OF THE GYRO I JUST ADDED

 

[beihan62]

Hi Apfsds,Sorry I cant help with identifying the gyro but what an interesting electro machanical peice of engineering,
thanks for posting,
Don,

 

[apfsds]

Thank you, Don!

I have been fascinated by torpedo guidance gyros for years now and have put together a descent collection. The older spring and or air driven gyros are true engineering works of art. I am not certain on the date of this electric gyro but am guessing 50's, 60's, or 70's?


Jason

 

[beihan62]

Hi Jason,I think you could be right re the wiring leaning a bit more towards 60s or 70s,your latest gyro looks to be the same gyro mounted on a smaller base perhaps for a smaller diameter weapon,a fascinating piece of quipment,well done collecting it,
Regards,
Don,

 

[apfsds]

Thank you, Don. I agree, it is the same gyro mechanism with different electronics and mounting armature Most likely it for a different torpedo or a different MOD of the same torpedo?

Jason

 

[gravelbelly]

Thank you, Don. I agree, it is the same gyro mechanism with different electronics and mounting armature Most likely it for a different torpedo or a different MOD of the same torpedo?

Jason

Hello Jason,

The two photos you posted of the Mark 20 Torpedo and gyro came from me a few years ago. That gyroscope is lying on my desk now.

The Mark 20 was an early generation electrically powered, acoustically guided, torpedo which was in service in the Royal Navy up until about 1980. Before firing a number of parameters such as; gyro angle, range, running depth, ceiling and floor depth of search pattern etc. could be set mechanically via dog clutches through the wall of the torpedo tube. If the torpedo was loaded into the stern tubes of the submarine (to knock out an anti-submarine surface vessel which was giving chase) then these clutches were not accessible at sea so some sort of "generic" parameters had to be set in advance.

In order to be able to change settings, right up to the moment of firing the torpedo, methods of applying these settings via electrical umbilical cable and on-board servo motors were developed. Whilst newer, faster, more sophisticated, torpedoes were under development there were still many Mark 20's available in store which could still be useful in the stern defence role. Vickers Limited, Barrow-in-Furness, acquired two mark 20's, with spare gyros, from the Ministry of Defence for use in trials of a cable-set system. The gyro in my early photo is one of the modified gyros with the servo gubbins in the box above the gyro. I believe that only two of these gyros were modified for cable setting and two were were retained as original clutch mechanical settings for comparison firings.

I cannot access the original gyro for this torpedo at the moment as I have crated the torpedo up for transport but I will post photos of the gyro next week. The gyro which you have posted photos of was clearly manufactured for cable setting which explains the neater bracket arrangement when compared to the experimental one.

gravelbelly

 

[apfsds]

Thank so much for the great, detailed information about this torpedo and its gyro developmental changes. I am always so amazed by your extreme knowledge of so many ammunition topics, Gravelbelly! It is always great to properly ID specimens in ones collection


Jason
PS: Do you have any idea how to un-cage it? Pressing on the arming lever will not make it switch settings so I'm thinking it is either stuck or electrically released?

 

[gravelbelly]

Thank so much for the great, detailed information about this torpedo and its gyro developmental changes. I am always so amazed by your extreme knowledge of so many ammunition topics, Gravelbelly! It is always great to properly ID specimens in ones collection


Jason
PS: Do you have any idea how to un-cage it? Pressing on the arming lever will not make it switch settings so I'm thinking it is either stuck or electrically released?

Jason,

The gyro gimbal is caged (locked) by a pin which you should be able to see passing through the gimbal and into a groove around the spherical wheel. That caging pin is controlled by a bell-crank lever, one end of which has the "cocked" and "fired" legends marked alongside it. If you look at the other end of the lever you can see that it is connected to the caging pin via a rack and pinion arrangement. The lever is held in the "cocked" position by the plunger of an electrical solenoid. If you push the tip of the plunger up the lever will be released, withdrawing the caging pin and freeing the gimbal and wheel.

I will attach a photo, looking into the housing for the gyro, where you can see two of the shafts for setting pre-launch parameters.

gravelbelly

 

[apfsds]

Thank you so much, Bud! I really appreciate all of your help.I had a feeling it was electrically released. I have the gyro all boxed up now so am going to have to wait to try your un-caging technique. I printed your instructions THANK YOU!

Jason