A four-inch Stokes Mortar team, 1915 (c)

Photograph by Lieutenant Patrick Robert Koekkoek, Royal Engineers, World War One, Western Front (1914-1918), 1915 (c).

The Stokes Mortar consisted of a smoothbore metal tube fixed to an anti-recoil base plate. When a mortar bomb was dropped into the tube, an impact sensitive primer in the base of the bomb would make contact with a firing pin at the bottom of the tube, and detonate, firing the bomb towards the target. The four-inch version of the Stokes Mortar was primarily used to fire smoke, gas and thermite rounds.

One of 188 photographs taken by Lieutenant Patrick Robert Koekkoek, Special Brigade, Royal Engineers.