The Cruiser tank Mk V or A13 Mk III Covenanter was a British cruiser tank of the Second World War. The Covenanter was the first cruiser tank design to be given a name. Designed by the London, Midland and Scottish Railway as a better-armoured replacement for the Cruiser Mark IV, it was ordered into production in 1939 before pilot models were built. Problems with the design became apparent only after production was under way. The tank equipped various British armoured divisions for home defence and training. It never left the UK as poor engine cooling caused the Mk I to Mk III to be declared unfit for overseas service especially in hot climates. This was rectified in the Mk IV after many corrective actions were undertaken but, by February 1944, it was declared obsolete. More than 1,700 of the type were built. It was named after the Covenanters, a Scottish religious faction at the time of the Wars of the Three Kingdoms. Development In 1938, the War Office had issued a requirement for a new, better armoured "heavy" cruiser tank to replace the Cruiser IV. Nuffield's A16 (and the A14) design was found to be too expensive and, in 1939, a cheaper and lighter cruiser tank – under General Staff specification A13 Mk III Cruiser Mark V – was chosen to be developed. It had nothing apart from Christie suspension and armament in common with the other A13 specifications. The initial specification required a QF 2 pounder gun, at least one machine gun, the same A13 Christie suspension in a lower hull, epicyclic steering transmission and "armour standard" of . The "30 mm armoured standard" referred to any vertical plate having to be 30 mm thick. Angled surfaces (through the principles of sloped armour) could be thinner, provided they were at least as effective as a 30 mm thick vertical plate. From these, a design using many sloped surfaces was chosen to keep the weight low. To keep the silhouette low, the suspension used cranked arms and a low profile engine was envisaged. The engine, which was to be specifically designed for it, was to deliver at least . The Wilson transmission and steering of the A16 would be used. Design work was by the London, Midland and Scottish Railway Company (LMS), who had no prior experience in the design and production of fighting vehicles and had been invited to