T30
| T30 | |
|---|---|
T30 prototype on the "Aberdeen Proving Ground" |
|
| General properties | |
| crew | 6th |
| length | 11.56 m |
| width | 3.8 m |
| height | 3.22 m |
| Dimensions | 64.7 t |
| Armor and armament | |
| Armor | Tub front: 102 mm Tub side: 76 mm Tower front: 178 mm Tower side: 127 mm Cannon aperture: 203-279 mm Top: 38 mm Bottom: 25 mm |
| Main armament | 155 mm T7 L / 40 gun with 34 shells |
| agility | |
| drive | Continental AV1790-3 525 kW (704 PS) |
| suspension | Torsion bar |
| Top speed | 27 km / h |
| Power / weight | approx. 8.2 kW / t (11.2 PS / t) |
The T30 is a US Army heavy battle tank from the Second World War , but it never got beyond the prototype stage. A special feature of the tank was the 155 mm T7 gun, which was one of the heaviest cannons ever mounted on a tank.
history
The development of the T30 can be traced back to the summer of 1944, when the US Army, due to the experience from Europe with the heavy tanks of the Wehrmacht, had a new interest in the development of a corresponding vehicle. In previous years, numerous tank projects had failed, such as the M6, which had even been developed for series production by the end of 1942, but series production was canceled in favor of the M4 Sherman . When, after the landing in Normandy, it became increasingly clear that the M4 was hopelessly inferior to the German Panther and Tiger I tanks , the Army reacted and developed the T26, later the M26 Pershing , to readiness for series production. However, the Germans introduced the Tiger II (also known as the "King Tiger ") during the same period , although it was foreseeable that the Pershing, whose use was delayed by internal disputes, would again be inferior to it. Therefore, on September 14, 1944, the US Armed Forces recommended the development and manufacture of four prototypes for a new heavy tank. Two of these were designated as T29s and were armed with the 105mm T5E1 cannon. The remaining two were designated the T30 and were armed with the 155mm T7 cannon.
The first two T30 prototypes began the testing program at Aberdeen shortly after the T29. The first came on the proving ground in April 1948, followed by the second in July. Since the T30 prototypes were originally intended as a parallel development to the T29, they initially had a correspondingly high level of component agreement. However, this changed early on in the conception phase when it was decided to replace the Ford GAC engine with the air-cooled Continental AV-1790-3 V-12 engine, which developed up to 810 hp (at 2800 rpm). One of the main focuses of the T30 test program at an early stage was to coordinate the new engine with the CD-850 cross transmission.
The hull of the T30 was identical to that of the T29, with the exception of the necessary changes in the engine compartment. The turret was also in large parts very similar to that of the T29, but more extensive adjustments had to be made for the 155 mm T7 cannon. a. one of the machine guns removed. The T7 gun had a relatively low muzzle velocity of around 700 m / s, which was compensated for by the high projectile weight of 43 kg. This in turn meant that, as with the 105 mm gun of the T29, the grenades and the propellant charge had to be stored and loaded separately on the T30 . The propellant charge weighed about 18 kg, so that the total weight was around 61 kg. Since such a weight is too great a workload for two loaders for quick firing sequences, an automatic rammer was built in to assist. Even in the run-up to the tests, it was to be expected that there would be considerable difficulties in handling the heavy ammunition inside the tank. Therefore, on July 24, 1947, the US Army approved the installation of this automatic rammer and a mechanism to automatically eject the cartridge cases. This converted prototype was now called the T30E1, the modified 155 mm gun was now carried under the identifier T7E1. Since, despite these adjustments, the handling of the ammunition continued to be a problem during the test series, a lifting device was also installed.
At the end of 1948 the test program was stopped again. Ultimately, despite the numerous adaptations, the T7 cannon had proven to be too expensive for a main battle tank. Since the ballistic properties of the 155 mm gun were also problematic, it was decided to abort the program. As a result, a prototype was equipped with the 120 mm T53 cannon, which was much more suitable for anti-tank combat, and was referred to as the T34 (originally T30E2) and sent to a separate test program. In contrast, the second T30 was taken out of service and exhibited in Fort Knox , where it can still be viewed today.
T58
In the 1960s, the T7 cannon was used again for a tank project, the T58 . The US Army was looking for a successor to the M103 . For this purpose, the T7 gun was modified with a revolver magazine and designated as the T180. This simplified the workload for the crew, but the ballistic properties of the T180 were still unfavorable for fighting tanks, so the T58 also failed. Ultimately, it was a fundamental problem, which is why the US Army refrained from using such a large caliber in all subsequent tank projects .
literature
- Hunnicutt, RP Firepower: A History of the American Heavy Tank . Novato, California: Presidio Press, 1988. ISBN 0-89141-304-9 .
Web links
Individual evidence
- ↑ original: "an automatic cartridge case ejecting mechanism" which very likely means that the case is conveyed directly to the outside from the closure