In May 1936, the "Conseil Consultatif de l'Armement" accordingly decided that French industry would be invited to initiate studies on the design of a tank having sufficient protection and armament to fight other armour, but light enough (twenty tons or less) to be both cheap and mobile. However, during this period, it began to be increasingly realised that the Char B1 was overly complex and expensive and two tonnes heavier than necessary because of using riveted armour plate instead of cast or welded armour. A twenty-tonne tank would be lighter, swifter, cheaper, more easily produced and require less training. It was therefore also decided that the new twenty-tonne tank should be able to serve as a future battle tank, eventually replacing the older heavy tank.