JR Potts, AUS 173d AB (Updated: 6/2/2016):
The T-28 wielded a main gun armament consisted of a 105mm T5E1. This was supplemented by an anti-personnel 0.50 caliber Browning M2 heavy machine gun fitted above the crew hatch as a secondary weapon. The 105mm main gun fielded a muzzle velocity of 3,700 feet per second (1,130 m/s) with a range of up to 12 miles (19 km). The T28 tank had only a few differentiating qualities from past and contemporary American tank designs. For example, crew accommodations amounted to four personnel instead of the usual five. But perhaps the most interesting of these qualities was the lack of a traversing turret for the main gun, the gun instead traversing from its hull-mounted position and limited to 10 degrees right and 11 degrees left. Elevation was from a maximum of 19.5 degrees to minimum of -5 degrees. This limitation, coupled with the low-profile casement-type hull, meant that the tank was expected to concentrate its firepower against forward-placed targets or areas. It was the lack of a 360-degree traversing turret - common to conventional tanks even today - that categorized the T-28 more as a "self-propelled gun motor carriage" and not a tank proper. In 1945, the T28 was redesignated as such to become the "T95 Gun Motor Carriage". However, in 1946, the T95 was redesignated yet again to become the "Super Heavy Tank T28".
The T28 hull measured in at 11.10 meters long and was 4.39 meters wide with a height of 2.84 meters. Its total weight, when fully equipped, would have reached 95 tons. The armor was massive compared to other tanks of the day - 12 inches at her thickest. The lower front hull alone was covered by 5.25 inches (130mm) of armor while the sides totaled up to 2.5 inches (64mm) in thickness. The suspension area itself was allocated 4.0 inches (100mm) of protection. The armor of the T28 would have been powerful enough to deflect the fabled 88mm projectile round used by German heavy tanks such as the Tiger II. However, the developmental German "Maus" super heavy tank was being fitted with a combination arrangement consisting of a 128mm main gun and a 75mm secondary main gun.
As the T28s maximum field load was listed at 95 Short Tons, four individual sets of tracks were required to spread the weight of the vehicle over different soil types (in comparison, conventional tanks used one set of tracks). Each set was 12.9 inches (328mm) wide. When running on paved roads, the outer two tracks could be removed and actually towed behind the tank itself if an Army support truck was not available. The engine was underpowered for the listed weight ratio and consisted of a gasoline-fueled, Ford GAF V-8 series powerplant delivering up to 500 horsepower. However, field tests gave the T28 a top speed of only 8 mph (13 km/h), making her something of a liability by any regard. Conversely, the war-winning M4 Sherman could reach road speeds of 25- to 30-miles per hour. The T28, therefore, would have had trouble keeping up with a mobile mechanized front - considering she was to be used as the spearhead of such an action. As such, her actual battlefield usability was obviously doubted as the project progressed but this was world war and solutions were nonetheless needed.