S-51 Self-Propelled Gun
The S-51 was an experimental heavy self-propelled gun designed by TsAKB.
| S-51 | |
|---|---|
| Type | Self-propelled gun |
| Place of origin | Soviet Union |
| Production history | |
| Designer | TsAKB |
| Designed | 1943 |
| Manufacturer | TsAKB |
| Produced | 1943 |
| No. built | 1 |
| Specifications | |
| Mass | 49.7 t (110,000 lb) |
| Length | 9.35 m (30 ft 8 in) |
| Width | 3.35 m (11 ft 0 in) |
| Height | 3.40 m (11 ft 2 in) |
| Crew | 9 |
| Armor | 75mm front
60mm side 30mm rear |
Main armament | 1x 203 mm howitzer M1931 (B-4) |
| Engine | V-2K 12 cylinder diesel engine 600hp |
| Transmission | mechanical 8-speed gearbox |
| Suspension | torsion bar |
| Maximum speed | 35 km/h (22 mph) |
History
At the end of 1942, the Red Army switched from defensive to offensive operations which revealed the need for self-propelled artillery. Against pillboxes and fortified buildings in urban battles, the firepower of towed and self-propelled artillery of 152.4mm caliber was sometimes not enough. To solve this issue, the Red Army was armed with the towed 203 mm howitzer M1931 (B-4). However, the 203 mm howitzer was unarmoured which makes attacking risky and had low speed which made swift breakthrough of enemy lines impossible.[1]
Therefore, the Red Army initiated a project for a heavy self-propelled gun. Plant № 100, CB Uralmash, and TsAKB took part in this competition. Plant № 100 under the leadership of Josef Yakovlevich Kotin created a self-propelled gun carriage that looks similar to the Canon de 194 mle GPF. The design by CB Uralmash was two 152mm howitzers on two connected SU-122 chassis.
In the autumn of 1943, the TsAKB designed and built a self-propelled gun on the basis of the KV-1S equipped with the 203mm howitzer. The self-propelled gun received the designation, S-51.[1]
Description
Hull
The S-51 had a very long hull and an open topped fighting compartment. The front, side and rear of the hull had 75 mm, 60mm and 30 mm of armour respectively. The hull only has a driver’s compartment and can seat one out of the 10 crews required. The engine and transmission are located in the rear of the hull. The hull also had a bottom hatch for emergency escape and a number of small hatches for access to the other modules of the vehicle. [1][2]
Armament
The S-51 was armed with a modified 203 mm howitzer M1931 (B-4). The gun was mounted at the front of the vehicle with gun shields. The elevation of the gun was 0 to +60 degrees. The gun traverse was 4 degrees to either side. The ammunition was 12 rounds and the vehicle can fire HE and armour piercing shells. The shells and propellant charges were placed behind the gun shields of the vehicle.[2]
During transport, the gun shields were let down and the barrel of the howitzer was turned to the center of the hull.[1]
Engine
The S-51 was powered by a four-stroke V-shaped 12-cylinder diesel engine V-2K. The engine can produce 600 hp allowing the vehicle to travel at 35 km/h. The engine was started by a starter ST-700 with a capacity of 15 liters. Fuel tanks with a volume of 600-615 liters were located inside the hull.[1]
Transmission
Self-propelled artillery mount S-51 was equipped with a mechanical transmission. Unreliable operation of the transmission group was noted during its testing. This fact served as further confirmation of the thesis that transmission defects were one of the most significant shortcomings of the KV series tanks and vehicles based on it.[1]
Development
In February 1944, the S-51 underwent factory testing. It was transferred to the artillery testing ground before completing the factory tests due to the great interest in the heavy self-propelled gun project.
During the trials, many flaws of the S-51 was uncovered. When the gun is elevated and fired, the gun will sway and the recoil will push the tank back. When the gun is elevated at a small angle and fired, the recoil will be so strong that the crew could not stay in place. Overall, the KV-1S chassis was deemed to be unsuitable for mounting guns of this caliber.
Due to these problems, the S-51 did not enter mass production.[1]
References
- "S-51 \ S-59 Self-propelled artillery unit of special power" (in Russian). Retrieved 14 March 2020.
- Pasholok, Yuri. "Work on experimental self-propelled guns, early June 1944" (in Russian). Retrieved 14 March 2020.