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 cross-country transport.