Staff Writer (Updated: 6/2/2016):
The T30 made use of one of the largest guns ever fitted to an American tank - this being a 155mm T7 L/40 main gun. The main gun was fitted into a fully traversing turret protected by slab sided surfaces with rounded edges, giving the entire tank a rather high, however necessary, profile. The barrel was capped at the muzzle with a baffled muzzle brake to content with the main gun's recoil. Thirty-four projectiles of 155mm ammunition were afforded the system and crew and would have comprised both armor-piercing (AP) and high-explosive (HE) types. The main gun was supplemented by 0.50 caliber, coaxially-mounted Browning HB M-2 machine gun as well as a Browning M1919A4 0.30 caliber, bow-mounted general purpose machine gun.
The turret was set onto a conventionally arranged chassis featuring a tracked wheel assembly dominated by eight road wheels to a track side. Suspension was torsion-bar oriented and each track width was noticeably wide to contend with varying soil types. A well-sloped glacis plate protected the front of the tank by helping to deflect any incoming enemy shells by supplying awkward angles. The chassis was powered by a single Continental-brand AV1790-3 series, air-cooled, gasoline engine of 704 horsepower output. This provided for speeds up to 16.5 miles per hour on paved road surfaces, though lesser so when heading off-road.
The T30 weighed in at roughly 145,000lbs (72.5 tons). Her length was listed at 37 feet, 11.5 inches with a width of 12 feet, 5.5 inches and a height equal to 10 feet, 6 inches. A crew of six would have managed her various critical stations on the battlefield had she ever gone into production and operational service. These crew positions would have encompassed the tank commander, driver, two loaders, a gunner and a bow machine gunner. The two loaders were needed to operate and maintain the special loading function concerning the large 155mm projectiles - each weighing in at 98lbs. One loader managed the integrated crane responsible for maneuvering each shell into position while the other operated the rammer responsible for moving the shell into the firing chamber. Armor protection across all facings of the tank ran from 25mm (0.98 inches) to 280mm (11 inches) in thickness.