The flame-throwing Churchill Mk IV tank had a flame nozzle replacing its hull-mounted BESA machine gun which was repositioned in the turret. Fuel for the flame was carried in an armored trailer behind, consumption being four gallons per second. The trailer carried 400 gallons of thickened gasoline, it also carried bottles of pressurized nitrogen, which forced the fuel to the gun and ejected it. An explosive link allowed the trailer to be jettisoned from inside the tank if needed.
Each burst of fire lasted around a second. Tongues of flame could be projected up to 120 yards.
The Crocodile was used for clearing infantry positions such us isolated buildings, concrete emplacements, hedges, ditches and slit trenches.