“(3) The provision of mechanical transport, spare parts therefor, and petrol tractors up to the scale demanded.
“(4) The provision of locomotives up to the scale demanded.
And though by December the views of the authorities had changed considerably, the sudden expansion of the Tank building programme was not easy.
In October 1917, 700 Mark IV. Tanks had already been delivered in France, and a balance of about 500 was still due. But the Fighting Side was anxious that these should not all be of the unimproved Mark IV. pattern. For up to now no change in the design had been made since the first Mark IV. had been delivered. It was decided, therefore, that some of the 500 should be given Ricardo engines and Epicyclic gears, and that others should be fitted as Supply Tanks.
The M.W.S.D. hoped to build about 1600 new Heavy Tanks, 800 of which were to be of the Mark V. type and ready by May 1, and the others to be of other heavy types, probably Mark V. star and Mark VI., while 385 Whippet (“Medium A”) Tanks were also to be ready by May 1918.
Further, there was to be a small cadre of Salvage Tanks and of special infantry Supply Tanks, two of the latter being able to carry complete supplies for an infantry Brigade for one day.
A large number of these Tanks were as before to be built by the Metropolitan Carriage and Wagon Company.
A very brief account of most of these new types of Tank has already been given in Chapter I., and it is not necessary to repeat here the details of their speeds, armament, and so forth.
Salvage Tanks were usually Mark IV. Tanks on which special gear, such as winches and small cranes, had been fitted for hoisting wrecks out of the mud, or for towing.
The Supply Tank was a Mark IV. fitted with very capacious sponsons. In order to save weight these carriers were not made as fully armoured as the fighting Tanks.