Mk VIII "The International"

[David]

After the United States entered the war against Germany in April 1917, arrange­ments were put in hand so that the great manufacturing resources of the U.S.A. could be linked with British experience in tank design and operation to pro­duce tanks in quantity for the use of both countries. The "Allied" or "Liberty" tank or, more prosaically, Mark VIII Tank, was the result, although the intervention of the Armistice put an end to the plans for mass production. A broad specification for the heavy tank likely to be needed for the battles on the Western Front in 1918-1919 was produced in France and given to an Anglo-American tank committee under the joint chairmanship of Lieut.-Col. Albert Stern (U.K.) and Major J. A. Drain (U.S.A.) and comprising Sir Eustace d'Eyncourt and Captain A. Green (a Tank Corps officer) as British members and Major H. W. Alden, U.S.A. Under the guidance of this committee, Lieutenant G. J. Rackham, then at the beginning of a distinguished career in A.F.V. and more general automotive engineering, produced the detailed drawings for the Mark VIII. The new tank was recognizably an extension in design of earlier British tanks in layout and general appearance but it included many improvements suggested by earlier experience. The most fundamental of these was the complete separation of the engine com­partment from the crew compartment by a bulkhead. This reduced the fire risk for the crew and furthermore the venti­lating system kept the crew compartment at a slightly higher atmospheric pressure and so prevented fumes or heat from the engine entering. The armour protection was increased - compared with earlier British tanks - ­to a 16-mm. maximum, although the armament, two 6-pdr. guns and seven machine-guns, was comparable. The trend of increasing length to meet ever wider trenches and tank obstacles was continued in the Mark VIII, which was 34 ft 22 in. long and could cross a gap of about 15 ft. Although the Mark VIII at 37 tons was several tons heavier than previous tanks, performance was improved by the use of a 300h.p. power unit and decrease in track ground pressure through the adoption of 26.5- in. wide tracks. The engine intended for use in Mark VIIIs was the American “Liberty” aero engine, with the alternative of a new 300-h.p. Ricardo, although an epicyclic transmission and steering system was employed in either case. As mentioned, the Armistice put an end to the large-scale production plans for the Mark VIII, the first of which had been completed only just before fighting ceased. This was a hull shipped from England in July 191 8 to the United States where a “Liberty” engine and the transmission were added. The first tank to be completed in Britain (where only seven in all were built-by the North British Locomotive Co. Ltd., Glasgow) - was at first fitted with a Rolls-Royce aero engine. All the later tanks (and subsequently the first one also) were powered by the 300-h.p. Ricardo twelve-cylinder engine, which was made up of two six-cylinder units. In the United States it was decided to complete 100 tanks and these were built during 1919 by the U.S. Ordnance Department. One of the American tanks is shown in the drawings. This differed externally from the British tanks in the armoured jackets for the Browning machine-guns used instead of the Hotchkiss guns used by the Tank Corps, and in other details, notably in the raised commander's/driver's super­structure. Notice that these plans below are good but BIG: The photos below were taken by Phil Radley, at the Tank Museum in Bovington: And the photos below have been taken at the same museum, by Knut Erik Hagen: