The Gun Carrier was suggested as a companion machine to the Mark I Tank, to carry forward medium artillery and ammunition over shell-torn ground covered with old and new trench systems. It was apparent by mid-1916 that offensives on both sides (and notably the German attack at Verdun in February July 1916) soon lost their drive through the difficulty of bringing up artillery to maintain support.

The idea of a gun-carrying tank was put forward by Major J.R. Greg of the Metropolitan Carriage, Wagon and Finance Co., who were the builders of the greater proportion of Tanks Mark I produced. Design commenced in July 1916 and the prototype, built by the Metropolitan Carriage, Wagon and Finance Co., was running at the beginning of 1917.

The Gun Carrier, Mark I, as it became designated, used the main mechanical components of Tank, Mark I, including the steering tail wheels (which were later discarded). The purpose for which the Gun Carrier was designed, however, necessitated a changed arrangement and resulted in an entirely different appearance from the tank. The layout comprised an open space at the front in to which the artillery piece (usually a 60-pdr. gun or a 6in.howitzer) could be winched up a ramp, and behind this space an armoured box which contained a crew compartment and the engine and transmission. In the prototype, the driver and brakesman sat in the open over either track in front of the rear compartment, but in production machines two armoured cabs, either side of the breach of the gun, were fitted. This layout required the engine (a 105-h.p. Daimler) to be placed at the rear (unlike the Tank Mark I) with transmission shaft leading forwards to the differential which was located near the front of the armoured compartment. The final drive chains then led back to drive sprockets at the rear of the track assembly. Overall tracks, as in the heavy tanks, were not provided for in the Gun Carrier and the fact that the tracks went through tunnels under the front crew cabs and the rear compartment led to difficulties with mud collecting at these points.

Forty-eight Gun Carriers were built (two similar machines were completed as Salvage Tanks), the majority of them by Kitson & Co at Leeds, by July 1917. In France, they were used far less for carrying artillery than ammunition. The vehicle was designed so that the 60pdr. gun or the 6in, howitzer could be fired from it, although from a practical point of view only the 6in. howitzer could be used in this way: These weapons were employed in this fashion at night on a few occasions and achieved some tactical success, but the Gun Carrier companies were eventually converted into supply companies and carried other supplies as well as ammunition. When transporting a medium gun or howitzer, sixty-four rounds of ammunition could be carried or, without the weapon 130 rounds, or approximately seven tons of supplies. It was estimated that six Gun Carriers with their combined crews of twenty-four men could carry a load which would otherwise require 1745 men - the only practicable alternative form of crosscountry transport.

Video courtesy of PDA

A new design of gun carrier was proposed by Wilson and Gregg in June 1917. This was based on Mark V tank hull, engine and transmission although the hull was somewhat wider than the Mark V and it was intended to use 26.5inch wide tracks. Sponsons were not fitted and were replaced by large doors in the side of the hull. It was not intended to fire a gun from the Mark II Gun Carrier so the gun was carried at the rear of the tank which gave the driver a good view forwards - a common complaint about the Mark I Gun Carrier. The gun, either a 6inch howitzer or 5inch gun was placed on tow ramps at the rear of the carrier and winched up the ramps until it hit the curved ramp end plates. Further winching pulled the ramps clear of the ground. The winch was driven from the epicyclic gears of the Mark V and the winch cable passed through the roof to a pulley behind the driver's cab. A further pulley was suspended from a tripod frame and the winch cable was attached to the lunette (towing ring) of the gun. There was space inside the hull for storage of 70 rounds of ammunition. Smaller calibre guns could be carried with a corresponding increase in ammunition storage. The project was never taken up and only proceeded as far as a wooden mockup of the design.

Source: David Fletcher in Wheels & Tracks Magazine, No. 58 (1997) Images: IWM Q14523, Q14569

Roger Todd of the Landships forum who found the article on the Gun Carrier Mark II.