Bellifortis,
The sympathetic fuze you asked about that features in the "NDRC Misc Weapons Report" was a joint ISRB and Admiralty Superintendent of Mines Design (SMD) development although most of the work was done by SMD. It was developed in time for the 'Cockleshell Heroes' raid on the Gironde led by Major Hasler RM.
The fuze was not particularly reliable and Cotterill of ISRB Stn IX designed a click diaphragm fuze with soluble plug delay but owing to pressure of work this fuze was passed to the USA for further development (resulting in their 'Concussion Fuze').
I will add some more detail later.
The sympathetic fuze you asked about that features in the "NDRC Misc Weapons Report" was a joint ISRB and Admiralty Superintendent of Mines Design (SMD) development although most of the work was done by SMD. It was developed in time for the 'Cockleshell Heroes' raid on the Gironde led by Major Hasler RM.
The fuze was not particularly reliable and Cotterill of ISRB Stn IX designed a click diaphragm fuze with soluble plug delay but owing to pressure of work this fuze was passed to the USA for further development (resulting in their 'Concussion Fuze').
I will add some more detail later.