In a thread under Members Collections I mentioned the diaphragm sympathetic fuzes developed in the US at the request of British SOE.
The photograph shows three Sympathetic Fuzes of a similar basic type:
Left
This is the HEP No 67 fuze supplied in small numbers by the US to SOE.
Centre
This is a British ISRB (SOE) model based on the HEP fuze. It was produced experimentally as Fuze, Sympathetic (Water Armed), Experimental and dates from April 1944. British work on the click diaphragm sympathetic fuze was started by E Cotterill at Station IX but due to the pressure of other work the prototype and drawings were sent to America for further development.
Right
US Detonator, Concussion (Air or Water), Type T-1 later standardised. A small number of these were made available to the British for evaluation/trials.
The photograph shows three Sympathetic Fuzes of a similar basic type:
Left
This is the HEP No 67 fuze supplied in small numbers by the US to SOE.
Centre
This is a British ISRB (SOE) model based on the HEP fuze. It was produced experimentally as Fuze, Sympathetic (Water Armed), Experimental and dates from April 1944. British work on the click diaphragm sympathetic fuze was started by E Cotterill at Station IX but due to the pressure of other work the prototype and drawings were sent to America for further development.
Right
US Detonator, Concussion (Air or Water), Type T-1 later standardised. A small number of these were made available to the British for evaluation/trials.