Tanks in World War I
The continued need for four men to drive the tank was solved with the Mark V which used Wilson's epicyclic gearing in 1918. Also in 1918 the French produced the Renault FT, the result of a co-operation between Estienne and Louis Renault. As mentioned before, it had the innovative turret position, and was operated by two men. At just 8 tons it was half the weight of the Medium A "Whippet" but the version with the cannon had more firepower. It was conceived for mass production, and the FT became the most produced tank of World War I by a wide margin, with over 3,000 delivered to the French Army. Large numbers were used by the Americans and several were also lent to the British.
German tanks in World War II
The Panther was a medium tank (45 tonnes) with a crew of five, which was designed to counter the Soviet T-34 tank. In weight it was comparable to Soviet heavy tanks. This tank was introduced in the Battle of Kursk, the largest tank battle in history. It had sloped armor which increased the effective thickness of the armor from to roughly , effectively making the front of the tank virtually impervious to enemy fire. However the sides of this tank were very vulnerable, ranging from only to of either barely sloped or completely flat armor plating. The tank carried a high-velocity 75 mm gun, which possessed more penetration than the Tiger's 88 mm gun at short range. Series production began in 1943. The tank was plagued with mechanical problems throughout its service life, several of which were never quite fixed, even after the war. Despite this, the tank is considered by some to have been the best tank in the war, and to have greatly influenced post-war tank designs, setting a role model for the balance of firepower, mobility, and armor protection.