The Tortoise originated with a requirement issued in April 1943 for a well-armoured assault vehicle that could break through heavily defended areas. The intention was that it should become one of ‘Hobart’s Funnies’, the specialist AFVs operated by 79th Armoured Division in support of other formations.
Nuffield Mechanizations Ltd carried out a series of 18 design studies to meet the requirement. Initially, these were for relatively modest tanks of 36 tons, but the constant improvements in German AFVs and anti-tank weapons forced a steady increase in armour and armament. By February 1944, the design had grown to 72 tons, armed with the new 32-pdr gun and three Besa machine-guns.
This design was approved, and 25 vehicles ordered that were to be operational by September 1945. Production of these huge vehicles, whose weight had now crept up to 78 tons, was a slow business, and with the end of the war the order was reduced to six.
