Explore the equipment issued to Auxiliary Units

Pull Switch

Later known as the Switch Number 1 Mark 1.

Development

Switch Number 10 – Time Pencil.

Number 13 Switch – a combination pressure, pull, or release device, which combined the trigger variations into one universal switch.

Switch Number 2 Mark 1 – Pressure Switch. Placed under something or disguised with camouflage it operated when a sufficient weight pressed on the top. This sheared a metal pin attached to the spring-operated striker, which then triggered the explosives connected with it

Switch Number 3 Mark 1 – Release Switch. 

Placed inside or under something, this switch operated in reverse to the pressure switch. When a weight was removed from it, or the closed part of the device released, for example the opening of a tin, this triggered the explosives connected to it. Often this was used by the army for booby traps. In the images the one with the added coil spring is Mark II.

Switch Number 4 Mark 1 – Pull Switch – As per number 1 but simpler in operation.

Switch Number 6 Mark 1 – Release Switch, operated as per Number 3 but a smaller, compact design, developed by SOE research for better concealment or for applications requiring a smaller device.

They were given one of Military Intelligence (Research)'s uglier weapons, the Switch No. 8 AP – or as it was later know to soldiers in the Western Desert, the open 'castrator'. This booby-trap device was issued to the Resistance in parts of Scotland, but because of the way it worked it was never actually planted in training. A metal tube painted matt black, about the size of a fountain pen, the stick pencil contained a firing pin and a spring shaped like an umbrella catch.

Switch Number 9 – L Delay, or Lead Delay. 

These are tins to hold wooden reels of trip wire for booby traps. 1 x .014'' x 50yds and 1 x .032'' x 25yds.

The trip wire can be pulled out from these tins, and cut off as required.