The 2S18 Pat-S is a prototype 152 mm self-propelled howitzer developed in the early 1980s under the Soviet Union.
However, it only existed as a prototype and was never put into mass production. At the time of development, the 2S18 Pat-S was a promising design. It is significantly more powerful than the 122 mm systems but is lighter and less expensive than the 152 mm 2S19 Msta-S howitzer. The collapse of the Soviet Union and the lack of threats from the West resulted in the project being suspended.
The terrible attrition of weapons on the Ukrainian battlefield gave unfinished Soviet projects a chance to revive. According to a video posted on Telegram on August 8, the Russian Kurgan Machine-Building Plant is working on the production and modernization of the 2S18 Pat-S 152-mm self-propelled howitzers based on the BMP-3 Infantry Fighting Vehicle chassis. Accordingly, this vehicle will be equipped with a 120 mm mortar or a 152 mm cannon, which will significantly increase the effectiveness of motorized rifle units.
2S18 Pat-S is designed to destroy artillery and mortar batteries, tanks, command and control units. The maximum firing range of the system is 20 km. The weapon system is built on a BMP-3 infantry fighting vehicle chassis. 2S18 is equipped with a UTD-29 diesel engine, with 450 horsepower allowing a maximum speed of 70 km/h, a range of 600 km. In addition, the use of the BMP-3 chassis allows the new combat vehicle to swim in waters at speeds of up to 10 km/h.
The main armament of the 2S18 Pat-S is the 152mm 2A61 Pat-S howitzer, originally designed as a towed howitzer but reconfigured to be self-propelled. The gun has a rate of fire of 6-8 rounds/min, a muzzle velocity of 540 m/s. Effective range from 4 to 15 km.
Only one prototype of the 2S18 was built, which after the termination of the testing program then remained in storage at the Rzhevsky range for about 30 years until the beginning of 2017, after which it was transferred to the Military History Museum in St. Petersburg.
According to Russian media, this self-propelled gun was not adopted by the Soviet army due to the obvious lack of ballistics of the gun, which provided a maximum firing range of 13.7 to 15.2 km. Such a range of destruction is clearly not relevant at the moment, especially against the backdrop of Western artillery systems supplied to Ukraine. Whether the 2A63 gun will be replaced with a more powerful one is not known. So far, there is no additional information.