The Tank, Infantry, Valiant (A38) was a British tank design of the Second World War that only reached the prototype stage. It was intended to meet a specification for a well-armoured, light-medium tank, for use against Japanese forces in the South-East Asia theatre. The prototype demonstrated that the design was a failure and this sole example produced was retained by the School of Tank Technology as a lesson to its students. The Valiant, under General Staff specification A38, began as a candidate for an assault tank, with the thickest armour on the lowest possible weight, for use in the Far East. It was to be similar in intention to the 40-ton A33 Excelsior although far lighter. As the Valiant managed the same 114 mm frontal armour with only 27 tons, it managed to achieve its primary goal, but only by making unacceptable compromises elsewhere. At a time when British tank design was already at its nadir, this "terrible price for the weight concession" led to what is probably the worst British tank of the war. The design brief of December 1943 called for three prototypes of a small, heavily armoured tank for the Far East. Speed across open country was less important, as was performance against armour. Design work started with Vickers, but they soon passed it to Birmingham Railway Carriage & Wagon, then finally Ruston & Hornsby, who built the single prototype in 1944. Vickers' original intention may have been to use parts of their Valentine infantry tank where possible, but this did not survive the production choices of the other manufacturers, nor was the running gear of the far lighter Valentine compatible with the needs of such heavy armour. The largest point of commonality was the choice of engine, the General Motors 6004 two-stroke diesel, as used in later marks of Valentine. Construction was like that of the Matilda infantry tank – large cast armour pieces bolted together. Suspension was by six equally sized wheels on each side, with independent wishbone suspension units for each, rather than bogies.