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.
Amphibious Combat Vehicle
The ACV 1.1 is to carry 10–13 Marines, have a swim capability similar to the AAV, and have equal or greater mobility to the M1 Abrams tank. Although tracks are traditionally considered better for all-terrain mobility, the Marines believe wheeled vehicle technology has advanced enough to enhance survivability and mobility in a 35-ton-class platform; the Marine Personnel Carrier technology demonstrator used "in-line" drive technology that enabled all four wheels on each side to pull together much like the way a track does which, combined with a higher ground clearance and central tire inflation system, substantially closes the maneuverability gap and results in equal or better maneuverability than the M1A1 and better performance over the AAV. Improved technology used to inform requirements to build ACV 1.2 vehicles will later be applied to delivered 1.1 versions to upgrade them to 1.2 standard. Each ACV 1.1 vehicle will have a 3-man crew, and two vehicles will carry a reinforced rifle squad. Armament will consist of an M2 .50-caliber machine gun in a remote weapons station, with the potential to install a stabilized dual-mount M2/Mark 19 grenade launcher turret. Potential water speeds are for a ship-to-shore capability at 8 knots.