The T28 was designed and manufactured by Pacific Car and Foundry. The mechanical superstructure was taken from a T23. The original plan was to build five prototype vehicles, with a production total of 25. Its total weight when fully equipped would have reached 95 short tons (86 tonnes). To carry this weight, it used four tracks instead of two, each 12.9 inches (328 mm) wide. The outer tracks could be detached for easier transport. After removal they could be fixed together to make a unit that could be towed behind the tank. Due to its extreme weight and low engine power, the T28 had extremely limited obstacle-crossing ability and could not cross any of the portable bridges available at the time, and so was considered impractical in the field and not suitable for production.
| T28/T95 GMC | |
|---|---|
| Type | Super-heavy tank |
| Place of origin | United States |
| Production history | |
| Manufacturer | Pacific Car and Foundry |
| Number built | 2 |
| Specifications | |
| Weight | 95 short tons (86.2 metric tons) |
| Length | 36 ft 6 in (11.1 m) |
| Width | 14 ft 11 in (4.39 m) |
| Height | 9 ft 4 in (2.84 m) |
| Crew | 3/4 |
| | |
| Caliber | 105 mm |
| Elevation | 19.5° to -5° |
| Traverse | 10° right, 11° left |
| Maximum range | 12 mi (19 km) |
| | |
| Armor | 12 in (300 mm) |
| Main armament | 105 mm T5E1 gun, with 62 rounds |
| Secondary armament | .50-cal machine gun, with 660 rounds |
| Engine | Ford GAF V-8 gasoline 500 hp (372 kW) |
| Power/weight | 5.8 hp/tonne |
| Suspension | double track |
| Operational range | 100 mi (160 km) |
| Speed | 8 mph (13 km/h) |
The T28 had no conventional turret, with a casemate style hull instead, giving it a comparatively low profile. Its main armament was a 105 mm T5E1 gun, in a ball-shaped gun mantlet set into the hull front. Although it was technically a part of a gun mantlet it was really attached to the hull. Due to this it was not a true tank at all, but a "Gun Motor Carriage". The traverse was limited to 10° right and 11° left, and elevation from 19.5° to -5°. When traveling, the gun was locked at the maximum elevation. It also had a .50 inch (12.7 mm) M2 Browning machine gun mounted above the commander's hatch. The main gun had a muzzle velocity of 3,700 feet per second (1,130 m/s), with a range of up to 12 miles (19 km).
The armor was very thick compared to other tanks of the time, up to 12 inches (300 mm) thick on the front. This was considered heavy enough to provide protection from the German 88mm gun used as tank gun and anti-tank guns. The lower hull front had 5.25 in (130 mm) of armor, and the sides 2.5 in (64 mm). The suspension system and lower hull were covered with 4-in (100 mm) thick steel skirts. The engine was a gasoline-powered Ford GAF V-8, delivering 500 hp, which left the vehicle underpowered with a top speed of about 8 mph (13 km/h) and greatly limited its obstacle-climbing capability.
