Self-propelled gun "Condenser-2P", index GRAU 2A3 - a heavy self-propelled unit weighing 64 tons, capable of sending a 570 kg projectile at a distance of 25.6 kilometers. It was not mass-produced, only 4 guns were made. The self-propelled gun was first shown at the parade on Red Square in 1957. The shown ACS made a splash among domestic spectators and foreign journalists. Some foreign experts suggested that the vehicles shown during the parade were fake, designed for the effect of intimidation, but in fact it was a real artillery system of 406-mm caliber, shot at a training ground.
The creation of a 406-mm self-propelled gun of special power in the USSR began in 1954. This ACS was intended to destroy large industrial and military targets of the enemy with conventional and nuclear projectiles located at a distance of more than 25 kilometers. Just in case, the USSR began to develop 3 nuclear super-weapons: a cannon, a mortar and a recoilless gun, with calibers significantly exceeding the existing atomic cannons. The huge caliber chosen arose as a result of the inability of Soviet nuclear scientists to produce compact ammunition. In the process of development, in order to ensure secrecy, the artillery system was assigned the designation "Condenser-2P" (object 271), only later the gun received its real index 2A3. The self-propelled gun was developed in parallel with the 420-mm self-propelled mortar 2B1 "Oka" (object 273), in accordance with the decree of the Council of Ministers of 18.04.1955.
The artillery part of the ACS (guidance and loading mechanism, the swinging part) was designed by TsKB-34 under the direction of I. I. Ivanov, here it was assigned the SM-54 index. The horizontal aiming of the gun was carried out by turning the entire ACS, while precise aiming was carried out using a special electric motor through the turning mechanism. The vertical guidance of the gun was carried out using hydraulic lifters, the weight of the projectile was 570 kg., The firing range was 25.6 km.
Due to the fact that there was no suitable chassis for mounting such a large weapon in the USSR, the OKBT of the Leningrad plant named after Kirov for the ACS 2A3 "Condenser-2P" on the basis of assemblies, parts, technical solutions of the undercarriage of the heavy tank T-10M (object 272), a new eight-roll undercarriage was created, which received the designation "object 271". When developing this chassis, the developers focused on the need to perceive large recoil forces when firing a shot. The chassis developed by them had sloths and hydraulic shock absorbers that were supposed to partially dampen the recoil energy. The power plant for this ACS was borrowed from the T-10 heavy tank, practically without undergoing any changes.
In 1955, at the plant No. 221, work was completed on the creation of a 406-mm experimental ballistic barrel SM-E124, on which the shots for the SM-54 gun were tested. In August of the same year, the first fully equipped artillery unit of the SM-54 gun was ready at the plant. Its installation on the chassis of the Kirov plant was completed on December 26, 1956. Tests of the ACS "Condenser-2P" took place from 1957 to 1959 at the Central Artillery Range near Leningrad, also known as the "Rzhevsky Range". The tests were carried out in conjunction with a 420-mm self-propelled mortar 2B1 "Oka". Prior to these tests, many experts were skeptical that this self-propelled gun mount could survive a shot without being destroyed. However, the 406-mm self-propelled gun 2A3 "Condenser-2P" quite successfully passed the tests by mileage and firing.
At the first stage, the ACS tests were accompanied by numerous breakdowns. So, when fired, the recoil force of the SM-54 cannon installed on the self-propelled gun was such that the self-propelled cannon on a caterpillar track rolled back several meters. During the first firing using simulators of nuclear projectiles, sloths were damaged in the self-propelled guns, which could not withstand the enormous recoil forces of this weapon. In a number of other cases, cases were noted with the collapse of the installation equipment, the breakdown from the gearbox mountings.
After each shot, the engineers carefully studied the condition of the material, identified weak parts and structural units, and came up with new technical solutions to eliminate them. As a result of such actions, the design of the ACS was continuously improved, the reliability of the installation increased. The tests also revealed low maneuverability and cross-country ability of the ACS. At the same time, it was not possible to defeat all the discovered shortcomings. It was not possible to completely extinguish the recoil of the gun; when fired, the gun moved back several meters. The horizontal guidance angle was also insufficient. Due to its significant weight and size characteristics (weight about 64 tons, length with the gun - 20 meters), it took a significant amount of time to prepare the positions of the ACS 2A3 "Condenser-2P". The specified firing accuracy of the gun required not only accurate aiming, but also careful preparation of the artillery position. To load the gun, special equipment was used, while loading was carried out only in a horizontal position.
A total of 4 copies of the 406-mm Condenser-2P self-propelled guns were made, all of them were shown in 1957 during the parade on Red Square. Despite the skepticism of a number of foreign military personnel and journalists, the installation was militant, although it had a number of significant drawbacks. The mobility of the artillery system left much to be desired, it could not pass through the streets of small towns, under bridges, over country bridges, under power lines. According to these parameters and in terms of its firing range, it could not compete with the divisional tactical missile "Luna", therefore, the ACS 2A3 "Condenser-2P" never entered service with the troops.
