Clive;
Gun Carrier, 3in, MkI, Churchill: - consisting of a fixed armoured box mounted well forward on a Churchill hull, with a three inch gun mounted in the front plate. The gun's traverse was limited to a mere five degrees either side of zero.
In September 1941, the General Staff asked the Tank Board to investigate the possibility of producing cruiser and infantry tanks mounting large calibre high velocity guns specifically for engaging the largest German tanks. to fulfil the crusier tank requirement the Challenger (qv) was subsequently developed with the 17pdr guns. For the infantry tank requirement it was proposed to fit a 3in AA gun in a limited traverse mount on a Churchill chassis. These weapons were available having been replaced in AA units by the 3.7in gun. a hundred vehicles were provisionally envisaged, but in December 1941, it was decided that all Churchill production would be needed for gun tanks, fitted with the 6pdr then just available. The order was thus reduced to 24 vehicles only. The pilot model was produced in February 1942 but these vehicles were never used operationally. Most were converted to carry Snake mine-clearing equipment and used for trials and training with this in 1943-44.
Picture attached, Cheers