Abstract: An electrical circuit breaker in which the circuit is immediately broken by concussive distortion to the unit housing which is secured to a vehicle or aircraft powered by an internal combustion engine utilizing a storage battery as an electrical energy source. The circuit breaker consists of a non-conductive tube containing a series of interlocking insulating cones each having a conductive core forming a connection which is the equivalent of a cable completing the electrical circuit with a break-away feature which insures disconnection automatically upon distortion for fire protection. Concussive distortion of the tube instantly and permanently separates the cones and breaks the circuit.