FCM-36
The FCM-36 infantry tank was presented in 1936 and had innovations such as the use of welded rolled steel plates instead of cast hull and turret. They also had a diesel engine that allowed them to operate more than 16 hours instead of the usual 8 hours of gasoline engines. Armored skirts were mounted on the sides to protect the tracks and for the first time, protection against chemical gases was installed. The FCM-36 was an expensive and a very complicated to manufacture tank, and the construction of the 100 units ordered by the French Army was delayed for 15 months. Finally they were delivered in 1938, but a second order for one hundred more FCM-36s was canceled because the cost was going to increase by 60%. Many FCM-36s were destroyed in the 1940 German advance over France, although some were captured by Germans and converted into self-propelled guns.
FCM-36 gallery and more info