A shock tube initiator (STI) for allowing the remote and/or manual initiation of at least one shock tube, typically two shock tubes is disclosed. The STI consists of: a) at least one coupling 8, connected to a shock tube containing a shot shell primer that upon firing initiates burning of the shock tube, b) a cockable mechanical firing mechanism 7 adjacent to the coupling 8 wherein the mechanical firing mechanism 7 is adapted to strike respective firing pins 9 within the couplings, c) a safety mechanism 15 adapted to allow the mechanical firing mechanism 7 to ignite said explosive charge only when the safety mechanism 15 is moved from a safe mode position to an armed position, d) a rotary solenoid valve 24, electrically connected to and energised by a remote controlled operating system, and e) an actuator 10 positioned between and engageable with the rotary electro-mechanical energising means 24 and the firing mechanism 7 and wherein said actuator 10 is adapted to be actuated either by the rotary solenoid valve 24, when energised, or manually manipulated (13) to allow the cockable mechanical firing mechanism 7 when cocked, to ignite said shell primer.