T29 Super Heavy Tank

After the American T26E1 prototype was deemed a succesful design, and the M26 Heavy Tank began development, there was thought that even more heavily armed tanks would be needed. So, in early 1944, a new super heavy tank was designed to counter the new German heavy tanks, such as the Tiger II. With a 105mm high velocity gun, three .30 caliber machine guns (two coaxial and one mounted in the bow), a roof-mounted .50 caliber machine gun, very thick armor (279 mm on turret, 102 mm on hull), a crew of six, and a weight of 69.5 tons, the T29 was a true monster of a vehicle. The prototype had the same forward hull as the T26E3, but extended, with the addition of two more road wheels and a new engine, the Ford GAC 770hp. The top speed was 22mph, but the range, like the armor thickness, is now unknown. The T29 was not the only tank of this basic design however; it had two other 'siblings', as well as two improved variants, the T29E2 and E3. The specifications of the E2 have been lost to history, but it is known that the E3 model added a stereoscopic rangefinder to the turret, with two projector boxes mounted on the turret sides to assist in long range targeting.

T30 Super Heavy Tank
The T30 was a seperate tank, but developed in close relation to the T29. The T30 called for a few changes to the design, including a new 155mm T7 gun, and a new Continental AV-1790-3 810hp engine. These changes brought the weight up to 72.5 tons, and lowered the top speed to 17mph. The only noticable external differences between the two tanks were the shorter, fatter gun barrel and a new engine deck. Problems were found with the loading of the 155mm gun however, as the shell weighed so much that two loaders were needed, and even then it was a difficult task to load the gun. To help solve this problem, the turret had an internally mounted crane to assist the loaders. A Cold War development, the T58, replaced the huge cast turret with an oscilating two-part one. This allowed the fitting of an automatic loader to the large gun.

T34 Super Heavy Tank
The T34 was designed after the T29 and T30, and was but a slight change to the T30 design. Instead of a 155mm gun, the T34 featured a modified version of the 120mm anti-aircraft gun that was entering US service at the time. This new vehicle was given the highest prioity out of the three, because it had greater firepower than the 105mm gun but did not have as heavy ammunition as the 155mm gun. Although the T34 was never produced in large numbers, many of its design features were later used in the post-war M107 heavy tank, including its new 120mm gun.