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2B1 Oka SPA Self-Propelled Artillery (1957)

Authored By Staff Writer | Last Updated: 7/17/2013

The abandoned 2B1 Oka self-propelled artillery system mounted a 420mm main gun barrel.

The 2B1 "Oka" was a short-lived, heavy-class, self-propelled gun system developed by the Soviet Union at the height of the Cold War. Such large-caliber guns had proven the norm for decades and found renewed importance during World War 1 and into the interwar years leading up to World War 2. The French, British, Americans and Germans all became keen on the prospects of large-caliber guns and, while their tactical use was severely restricted, their simple existence often proved a psychological tool against civilian populations they might target.

A prototype of the 2B1 system was unveiled in 1957 at the legendary Kirov Plant in St. Petersburg, Russia. The 2B1 Oka's operating principle was relatively simple - to lob large explosive projectiles against target areas deep within enemy territory - as far away as 45 kilometers according to her design. The 2B1 made use of a mammoth 420mm cannon installation mounted to a tracked hull. The gun mount sat at the center of the hull roof. Eight double-tired road wheels dotted the track sides with each pair heavily strutted to counter both weight and recoil. The drive sprocket was mounted to the front of the track system with the track idler at the rear and at least four track return rollers were used. Heavy duty recoil struts straddled the main gun at its base and the gunnery crew would have operated in the elements for no cover was afforded - the 2B1 was essentially a rolling gunnery stage and nothing else. No muzzle brake was fitted to the smooth barrel system which was not tapered in any way. A single V12 diesel-fueled engine would have supplied up to 700 horsepower.

On paper, her self-propelled nature would have made her somewhat mobile and her lethal reach could have proven devastating but, in practice, there emerged too many deficiencies in her design. The long gun barrel made even basic transport of the vehicle highly impractical and the violent recoil of such a weapon stressed the gun mount, hull and track components to their extremes, leading to consistent failures of said systems. Even the required large 420mm projectiles made any attainable sustained rate of firing impossible to continue for stretches by the seven-man crew. The single engine fitting working against the vehicle's weight of 55 tons would have made her extremely limited operationally - especially when going at it off road. The end result became a machine of war that was more trouble than it's worth, resulting in cancellation of the program in 1960.

Like the Americans, the Soviets elected instead to focus financing and resources towards the development of newer battlefield missiles that could do the same job as the 2B1 Oka while reaching to distances that would have proven unreachable by projectile-based systems. At any rate, the 2B1 Oka became a novel attempt that later fell to the pages of history.

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Specifications for the
2B1 Oka SPA
Self-Propelled Artillery

Country of Origin: Soviet Union
Manufacturer: Leningrad Kirov Plant LKZ - Soviet Union
Initial Year of Service: 1957
Production: 1

Focus Model: 2B1 Oka SPA
Crew: 7

Overall Length: 0.00 ft (0.00 m)
Width: 0.00 ft (0.00 m)
Height: 9.84 ft (3.00 m)
Weight: 61.0 US Short Tons (55,300 kg; 121,916 lb)

Powerplant: 1 x V12 diesel engine delivering 700 horsepower.

Maximum Speed: 0 mph (0 km/h)
Maximum Range: 0 miles (0 km)

NBC Protection: None
Nightvision: None

1 x 420mm main gun barrel

Dependent on ammunition carrier.

2B1 "Oka" - Base Series Designation

Soviet Union