Staff Writer (Updated: 4/1/2016):
Holt had already built up a resume of experience in the construction of their Holt tractors. Holt therefore teamed up with General Electric Company (GEC) in an attempt to produce America's first tank system based on both of their manufacturing and design experiences. An all-new track was devised as a longer, ten-wheeled arrangement utilizing a vertical coil spring suspension system. The tracks were fitted to either side of the lower hull while a fixed "box" type armored assembly housing the engine, transmission and crew compartment made up the superstructure. The superstructure gave the Holt tank a most utilitarian appearance to say the least with the only physical attributes of note being the overhanging side sponsons. Armor protection for the crew varied throughout the design, reaching thicknesses between 6mm and 15mm. The crew would have been made up of six personnel, comprised of the commander, driver, gunner, loader and two machine gunners. Power was supplied by a Holt-brand 4-cylinder gasoline engine developing up to 90 horsepower and tied to a transmission system, both held in a compartment to the rear of the vehicle. A complex water-cooling system was engineered to help improve cooling and prevent transmission overheating. The engine served as a generator to the two electric GEC track motors powering each track (ala the French-based St Chamond tank, it too utilizing a Holt suspension system).
Armament for the Holt Gas-Electric Tank centered around the 75mm Vickers mountain howitzer (again, much like the French St Chamond tank). The howitzer was fitted to the forward hull with limited traverse. This was complimented by a pair of Browning 7.62mm (.303 caliber) machine guns for anti-infantry defense work to the sides of the vehicle. These machine guns would have been fitted into ball mounts within the side sponsons with both limited visibility and traverse.
When all was said and done, the Holt design proved an overall disappointment. For the most part, the tank failed to impress in its trials and the excessive weight (brought about by many factors including the transmission cooling system) worked against the performance. While the system fared adequately enough along level ground, its true deficiency lay in tackling elevations to which the tanks performance dropped significantly. Essentially, the Holt tank could not climb slopes effectively to be of much use to the US Army.
Top speed for the machine was a measly 6 miles per hour with an operational range equal to 31 miles.
Though their endeavor into designing America's first tank was over, Holt Manufacturing Company went on to become the well-known Caterpillar, Incorporated company - still a major producer of tractor systems even today.