Conception

conceptionSince armoured vehicles first appeared there has been a conflict between the additional cross country low speed ability offered by the track system and the high speed travel offered by wheels. Different designers and manufacturers have tried a number of ways to achieve the best balance between weight of armour and armament versus mobility. During the North Africa battles of the early second world war it became apparent to the British Army that they needed a vehicle with something approaching tank levels of armour and protection, armament comparable with the best of the day but also high speed mobility allowing fast movement over desert terrain. The British Government was not in a position to design and order radical new vehicles due to the heavy demands of producing existing vehicle types. Consequently they approached the United States, then not at war, to design a wheeled but heavily armoured vehicle to fight in the North African battles.

The American Government had themselves experimented with this concept producing their model T17, a 6 x 6 Ford designed vehicle which had been tested in mid 1941 with plans to deliver to the British. This vehicle was called the Deerhound by the British and 250 had been built but were not put into service by the British Army. At the same time General Motors Corporation, Chevrolet Division produced a new design which incorporated some of the better features of theT17. It ran however on four wheels not six and was considerably lighter.

The British issued specification called for 4 x 4 layouts with large section tyres capable of carrying and spreading the load of the heavy armoured body. Conventional springing, hydraulic steering and a good turn of speed were required and this caused Chevrolet some problems. At that time there were few available engines in the 250 horsepower class that were not already fully committed to tank production and they therefore looked backwards toward a solution that had been used in various other experimental armoured vehicles particularly in the 1930’s. They took two of their standard GMC 270 CID six cylinder in line engines as used on the GMC CCKW 353 and experimental DUKW and avoiding the mistake made by other manufacturers of having one engine drive each pair of wheels, coupled them via what were in effect heavy duty automobile automatic gear boxes through hydromatic clutches before bringing the two power drives together in a single large and very heavy transfer box. The new vehicle was known as the T17E1 but was also given an American designation M6 although this was not widely used. This new vehicle was presented to the British who tested it and found it to be very suitable for their needs. Regrettably production did not commence until mid summer 1942 and the first vehicles were not delivered to the British until early 1943. By then the battles in North Africa were over and the immediate requirement for a fast heavily armoured car had receded somewhat.