A specialised vehicle based on the British Matilda Tank, the ‘Hedgehog’ or ‘Projector’ was equipped with a 7 chambered spigot ‘Hedgehog’ naval mortar, which was housed in an armoured box on the rear of the tank’s hull. Elevated by hydraulics, the mortar unit did not have the ability to traverse, so was aimed by moving the entire tank to face the direction of the intended target. With each mortar projectile containing around 35lb of high explosive, the weapon may not have been particularly accurate, but if operated by a competent crew, could be devastatingly effective.