- Yes, as a tech tree vehicle
- Yes, as a premium vehicle
- Yes, as an event vehicle
- Yes, as a squadron vehicle
- No, I would not like to see the T58 in game.
Some believe this photograph to be a mockup or model, but others have cast doubt upon this. Noteworthy is the serial number on the left side of the tank: this matches the serial shown in the same position on a photograph of the tank without its gun installed (shown later). Also worth considering is that unlike a traditional model or mockup against a white background, the T58 pictured here casts no shadow, suggesting that the photo’s original background was removed. Possibly, as author R.P. Hunnicutt claims, this is indeed a photograph of the T58 heavy fully assembled (sans rangefinder and AA machine gun in this photograph).
History
The 155mm Gun Tank T58 was an American prototype heavy tank made in the immediate postwar period. Like the British, the Americans were exploring ways to defeat the Soviet IS-3 heavy tank. These solutions generally fell into the line of, “have more armor and a bigger gun than they do”. To this end, the “Tripartite Conference on Armor and Bridging of October 1951” recommended a specific requirement for a 155mm gun tank. The gun was meant to use HEAT and HEP (American designation for HESH) shells. The advantage behind these ammo types was that they would not lose effectiveness with range, unlike conventional armor piercing ammunition. The T58 was effectively an upscaled version of the 120mm Gun Tank T57. Both had oscillating turrets with an automatic loading system. Unlike the T57, however, the T58 used separated ammunition for its gun, and due to the nature of the 155mm ammunition, the automatic loading system was much different.
An illustration of the loading mechanism and the entire gun system inside the tank. The gunner, unusually, sat on the right side of the tank, while the loader and commander were on the left.
The T180 (formerly T7E2) cannon was a modified version of the low-velocity T7 cannon found on the T30 heavy tank that accepted ammunition from an automatic loading system. The T58 had a six-round drum to feed ammunition to the cannon. To load the gun, the loader had to first put the charge into the cylinder, followed by the projectile, which would be power-hoisted from the ready rack into the cylinder. The loader had to manually turn the cylinder to line up the proper shell type. Then, both the cartridge and projectile were rammed into the breech. Finally, once the gun fired, the cartridge would be ejected back into the cylinder, where the loader would manually have to remove it. Provided the loader wasn’t replenishing the cylinders, the six-shot drum provided a high rate of fire of 23 rounds per minute, but a lengthy replenishing process.
Since the T180 cannon was meant to fire chemical shells, high velocity was not required, and the shell velocity was only 2,300 ft/s (701 m/s). Even despite this, the gun was extremely potent for 1950’s standards. The HEAT shell offered 16 inches (406 mm) penetration at 0 degrees impact, with 8 inches (203 mm) penetration at 60 degrees. The HEP shell offered 7 inches (178 mm) perforation capability at all angles. The tank was able to store 32 rounds of 155mm ammunition, an impressive amount. Besides the main gun, the T58 had a 7.62mm Browning coaxial machine gun, as well as a 12.7mm anti-aircraft gun on the commander’s hatch. The automatic loading system necessitated an oscillating turret, as attempts to mount such a system on the T43 heavy tank’s turret (prototype of the M103) had previously failed. The T43 hull is effectively that of the M103, while the turret was completely new. It had 5 inches (127 mm) of frontal armor sloped at 60 degrees for both the hull and turret, offering very good protection. The oscillating turret was limited to a mediocre + 12 / - 8 degrees of elevation.
The main thing that killed the T58 project was the shift in U.S. doctrine to the main battle tank concept. As designers focused on more well-rounded concepts for new tanks, the heavy tanks would be left behind. Some other contributing factors were probably the lackluster mobility, poor travel range, and low velocity gun making first hit in engagements less likely. America’s last heavy tank, the M103, would be introduced shortly before the two T58 turrets were scrapped in 1957.
Specifications:
155mm Gun Tank T58
Crew: 5
Weight: 66 tons
Powerplant: Continental AV-1790-7 twelve cylinder gasoline engine
- 810 gross horsepower
- 650 net horsepower
Power to weight ratio: 12.3 hp/ton gross (9.8 hp/ton net)
Maximum speed: 22 mph (35.4 km/h)
Armament:
- Main gun: T180 155mm cannon (32 rounds)
- Rate of fire (six shots): 23 rounds/minute
- Traverse: 18 degrees/sec, 360 degree range
- Elevation: 4 degrees/sec, + 12 / - 8 degree range
- Muzzle velocity: 2,300 ft/s (701 m/s)
- HEAT ammunition: 406 mm (16 inches) armor penetration at 0 degrees, 203 mm (8 inches) at 60 degrees
- HEP ammunition: 178 mm (7 inches) armor perforation at any angle
- Coaxial machine gun: Browning M1919A4 7.62 mm (.30 cal) machine gun (6,500 rounds)
- Anti-aircraft machine gun: Browning M2HB 12.7mm (.50 cal) machine gun (1,200 rounds)
Armor:
- Hull:
- Upper glacis: 127 mm (5 inches) CHA at 60 degrees
- Lower glacis: 102 mm (4 inches) CHA at 50 degrees
- Upper side: 50.8 mm (2 inches) RHA at 0 degrees
- Lower side: 44 mm (1.75 inches) RHA at 0 degrees
- Upper rear: 38 mm (1.5 inches) RHA at 30 degrees
- Lower rear: 25.4 mm (1 inch) RHA at 60 degrees
- Turret:
- Front: 127 mm (5 inches) CHA at 60 degrees
- Sides: 83 mm (3.25 inches) to 70 mm (2.78 inches) CHA from 20 to 40 degrees
- Rear: 50.8 mm (2 inches) CHA at 40 degrees
Additional equipment:
- T50E1 stereoscopic rangefinder
Sources:
- AD0395259
- Firepower: A History of the American Heavy Tank by R.P. Hunnicutt (1988)
- https://tanks-encyclopedia.com/coldwar/US/155mm-gun-tank-t58
- Photographs of mounted turret acquired by Harold Biondo