Germany Following WWI, Germany was forbidden to manufacture weapons of war but the restriction was not always followed. In 1930, Hubert Ruhlemann designed the ECR or Electrical, Condenser ,Resistance fuze which was tested between 1931 and 1932 in Russia. The ECR fuze was designed for use on aerial dropped bombs. The fuze was connected to the aircraft and electrically charged (i.e., energized) before leaving the aircraft. As the bomb fell to earth, the electric charge would trickle through various resistors to a firing condensor. The impact of the bomb caused a sensitive vibrator switch to close the circuit and detonate the bomb through a firing bridge (similar to a match head) which created a flash that detonated the sensitive penthrite wax contained in the attached gaine, which is the steel or bakelite container screwed into the base of the fuze.

Shown below is a German 50kg bomb (without the fins) with a Type 25B ECR fuze.

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