Capable of firing continuously 12 times per hour, firing 750 kg nuclear projectiles up to 45 km away, the 2B1 Oka is the most fearsome nuclear supergun ever built.
In the early years of the Cold War, both American and Soviet strategic thinking assumed that the start of the next large-scale war in Europe would involve nuclear weapons many times more destructive than conventional weapons. This theory greatly influenced the strategists of both sides in the development of weapons for nuclear war from tanks, fighters, bombers and even artillery. This was the premise for the birth of tactical nuclear weapons.

During the mid-1950s, when missile technology was not yet developed, nuclear weapons were mostly deployed via bombers. With the development of technology, the size of the bombs gradually reduced to the point that they could be placed inside heavy cannons. A good example of this design was the US military’s M65 nuclear cannon.
At that time, the M65 was described as a super weapon that helped bring nuclear weapons to the front lines as well as limit the range of damage to a minimum compared to conventional nuclear bombs. To counterbalance the M65, the Soviet Union immediately sought to acquire a similar weapon. After the success of the 2A3 Kondensator 2P 406 mm self-propelled howitzer, the Soviet military set a larger ambition when developing the 2B1 Oka – the largest generation of nuclear-capable self-propelled artillery ever built.
The 2B1 Oka was built based on placing a 420 mm 2B2 cannon on the chassis of a T-10 heavy tank. The T-10 tank at that time was equipped with a diesel engine with a capacity of 750 horsepower, but the movement of the 2B1 Oka was still extremely difficult due to its large size.
With a caliber of 420 mm, the 2B1 Oka possesses a power that was not inferior to the firepower of the battleships of World War II, it was even superior to the ability to fire nuclear shells. The length of the barrel was up to 20 m, enough to fire nuclear shells to targets 45 km away. To make it easy to imagine, the Iowa class of US Navy battleships during World War 2 was only equipped with 16 inch (406 mm) Mark 7 gunboats, which is also the largest gun model ever used by the US Navy. Mark 7’s firing range was only about 39 km.

In theory, when deploying nuclear weapons, 2B1 Oka will fire a warhead with a weight of about 750 kg, a range of about 45 km with a flight time of about 20 seconds before reaching the target and detonating at a few tens of meters above the ground to maximize the destructive power. By design, tactical nuclear self-propelled guns such as the 2B1 Oka could fire continuously, but the Soviet doctrine of nuclear war at that time limited the number of times tactical nuclear weapons could be deployed to a single shot.
Only two years after the development project 2B1 Oka was approved by the Council of Ministers of the USSR, this self-propelled artillery model first appeared in public during the parade on Red Square on November 7, 1957. Its appearance attracted attention from Western countries. However, there was some skepticism about this cannon due to its poor maneuverability.

With a weight of up to 55 tons, the 2B1 Oka’s V-12-6B turbo diesel engine was not enough to be able to travel long distances and its range was only 180 km. Even the T-10’s sprocket and gearbox were prone to damage and require constant maintenance. Another problem, each shot of the 2B1 Oka would nearly destroy its tracked chassis system.
The 2B1 Oka was seen as more of a propaganda weapon than a combat weapon, and only six systems were tested. In addition, the change in nuclear doctrine of the United States and the Soviet Union in the mid-1960s, along with the emergence of ballistic missiles with longer ranges and safer than nuclear artillery shells, causing 2B1 Oka to lose its position. Currently, there is only one 2B1 Oka self-propelled howitzer in existence on display at the Russian Artillery Museum in the city of St. Petersburg.