- Yes
- No
TL;DR: T54E2 turret mounted on an M48A2 hull and refitted with a 120mm cannon, used for firing tests
History
In 1950, during the development of the M48 (then designated T48), the US Army was recommended to improve its armament to a 105mm cannon, made possible by its sufficiently-large turret ring. On the 6th July 1951, OTCM 33842 began the development of two new vehicles, designated T54 and T54E1. The former was to be fitted with a conventional turret, and the latter with an oscillating turret, both with an autoloader, and both mounted on the T48 chassis. The cannon was the 105mm T140, a lighter variant of the 105mm T5E2 mounted on the T29 Heavy Tank. Two prototypes of each were constructed.
T54 (left, scale model) and T54E1 (right, prototype)
In 1952, Detroit Arsenal began studies into a third turret design, similar to the T54’s, but without the autoloader. On the 18th May 1953, this vehicle was designated T54E2 and two prototypes were ordered. This was later increased to three. Despite largely successful testing, focus shifted to the more promising T95 series of MBTs. One variant of the T95 was proposed — designated T95E3 — with the turret of the T54E2. As such, two of the three T54E2 turrets were modified for the T95 chassis. The third was installed on a T48E2 pilot vehicle. The T54 series was cancelled in January 1957. In February 1958, it was ordered that both of the T54 turrets, and one of the T54E1 turrets, were to be scrapped.
One of the three T54E2 prototypes.
At the same time, the US was looking to upgrade the M48A2. The Bureau of the Budget believed the Army was not progressing fast enough in developing a modernisation, and as such, in May 1958, denied the production of more M48A2s after 1959. The Army was aiming to replace the M48A2 with the T95, but the vehicle was still largely experimental, and was thought to only be slight improvement over the M48A2. The decision was made to produce a new vehicle, designated XM60.
In October 1958, firing trials were held at Aberdeen to decide the main cannon for the XM60. Six guns were tested: the standard 90mm M41 on the M48A2 (included to test its new HEAT ammo), the 90mm T208E9 smoothbore (mounted in the T95E1 turret), the 105mm X15E8 (British L7) and the 105mm T254 (American version of the X15E8), both mounted in a modified M48A2, the 120mm M58 on the M103, and — the subject of this suggestion — the 120mm T123E6, mounted in a T54E2 turret, and fitted to an M48A2 hull.
| Cannon | Turret | Hull | Evaluation |
|---|---|---|---|
| 90mm M41 | M48A2 | M48A2 | Weak penetration |
| 90mm T208E9 | T95E1 | M48A2 | Superior ballistic characteristics to all others, but low accuracy and high gun wear |
| 105mm X15E8 | M48A2 | M48A2 | Ranked first |
| 105mm T254 | M48A2 | M48A2 | Lower accuracy than the British version — preferred, but only after suitable quality barrels could be produced |
| 120mm T123E6 | T54E2 | M48A2 | Slow rate of fire, two-piece ammunition |
| 120mm M58 | M103 | M103 | Not under consideration for the XM60 |
Clockwise, from top-left: M103 (120mm M58); M48A2/T54E2 (120mm T123E6), M48A2 (90mm M41), M48A2 (105mm T254*), and M48A2/T95E1 (90mm T208). *The 105mm T254 and X15E8 were mounted in the same vehicle.
The 120mm T123E6 was originally designed for use on the T95E6, and was a lightweight version of the 120mm M58 mounted on the M103. It could fire the same ammunition, and had near identical performance. Before the firing trials, the T123E6 was one of the two preferred candidates, alongside the 105mm T254.
XM60 concepts. On the left is the XM60 fitted with the 120mm T123E6, in a T95E6-style turret. On the right is the XM60 with the 105mm T254, in an M48A2 (T95E5) turret.
Ultimately, the 105mm cannon was selected for what would become the M60, and the 120mm armed T54E2 remained a testbed, presumably being scrapped not too long after. The vehicle likely did not receive an official designation. I will be using T54E2 (120), although alternatives could be M48A2/T54E2 (120), or M48A2/T54E2/T123E6.
Characteristics
The T54E2 (120) is armed with the 120mm T123E6. This cannon is capable of firing the same rounds as the M103: AP, HEAT-FS, and HE. The M358 APBC shell penetrates 301mm @ 0° @ 10m, and the M469 HEAT-FS shell penetrates 380mm @ 0° @ 10m. The former has a muzzle velocity of 1,067m/s, and the latter 1,143m/s. The turret is not fitted with an autoloader — the gun was noted to take longer than the M103 to reload, as it only had one loader. The actual reload rate is unknown, but would be longer than the 19.4s/14.9s (basic/ace) in-game on the M103. It is unknown how many rounds the vehicle could carry. The turret has a coaxial 7.62mm M1919A4 with 4750 rounds of ammunition, as well as a 12.7mm M2HB mounted in the cupola, with 1800 rounds of ammunition.
The T54E2 (120) has a decent amount of armour — with a maximum of around 120mm on the front of the turret, albeit heavily sloped. The turret sides and rear are thinner, at around 64 and 51mm respectively. The hull remains unchanged from the M48A2 — 110mm sloped at 60° frontally (~200mm effective). The sides are around 76mm, but are sloped in a ‘bathtub’ shape, and the rear is weak at 51mm.
The T54E2 (120) uses the M48A2 chassis, with a Continental AV1790-8 V12 825hp engine, connected to an Allision CD-850 transmission. The base M48A2 has a weight of 47.6t and a top speed of 48km/h. The standard T54E2 (M48A1 hull, 105mm main cannon) weighs 49.4t. It can therefore be assumed that the weight of the T54E2 (120) is around 50t.
Conclusion
The T54E2 (120) would be another addition to the T54 series of vehicles in-game (T54E1, T54E2), but would represent a much less well-known variant. Despite the upgraded weapon calibre, it would likely remain at the same BR as the T54E2 (7.7), due to the longer reload and lack of APDS rounds.
Specifications
Armament
- 120mm T123E6
- M358 APCBC
- 301mm @ 0° @ 10m
- M469 HEAT-FS
- 380mm @ 0°
- M356 HE
- 39mm @ 0°
- M357 Smoke
- M358 APCBC
- 1x 12.7mm M2HB
- 1800 rounds
- 1x 7.62mm M1919A4
- 4750 rounds
Armour
- Hull
- Same as M48A1/M48A2. 110/ 76/35 mm
- Turret
- Same as T54E2 in-game. 127/64/51 mm
Mobility
- Speed
- 48km/h
- Weight
- ~50t (estimated)
- Engine power
- 825hp, 16.5hp/t
Other
- Crew
- 4
Images
No other images appear to be available publicly.
Sources
Patton: A History of the American Main Battle Tank. R. P. Hunnicutt. pp. 126–142, 152–155
A Proposed Armament System for Medium Tanks. Technical Report AD0312751