The 2S4 "Tyulpan" was developed as a fully-tracked, self-propelled heavy mortar platform. The 30-ton system was first witnessed by the West in 1975 which gave birth to the NATO designation of "M1975" (not to be confused with the 2S7 "Pion", also given the NATO designation of M1975). It still maintains an active presence in the Russian Army inventory and has seen noted combat actions in Afghanistan (1979-1989) and Chechnya (1999-2009). The Soviet designation was consistent with the accepted practice of an alpha-numeric system ("2S4") and the association to a flower ("Tyulpan").
The Red Army witnessed the value of large-caliber mortar systems first-hand in World War 2. The Soviets therefore fielded a large collection of field mortars ranging from infantry level types to massive 240mm caliber monsters in their fight against the Germans. By the end of the war, the large-caliber mortar had managed a permanent foothold in the Red Army inventory and little was to change with the upcoming Cold War against the West. Development of a self-propelled and modern mortar carrier began in 1960.
Overall, the 2S4 is a rather utilitarian weapon system consistent with Soviet armor doctrine - "quick production and a big gun". The vehicle is assigned an operating crew of up to nine personnel making up both vehicle and mortar gunnery elements. The vehicle portion of the 2S4 is nothing more than a modified chassis of the GMZ-class minelayer complete with a torsion bar suspension system for adequate off road travel capabilities in keeping up with the main armored force. The hull contains the engine, transmission and driver position with the driver is seated front left. Power is supplied by a single V-59 series diesel engine developing 520 horsepower output. As a tracked vehicle, the 2S4 makes use of six double-tired road wheels to a track side along with a drive sprocket at the front of the hull and a track idler at the rear. There are four track return rollers present with no side armor skirts being used to protect these vulnerable areas. The hull superstructure is multi-faceted and rather low-set against the lower hull portion of the vehicle. The crew is relatively protected (20mm thick armor) but the 2S4 is not intended for direct combat against seen foes. It instead makes use of ranged fire support for the benefit of other allied ground components in action. The mortar portion of the vehicle consists of a massive 240mm M240 series heavy field mortar made up of a launch tube and baseplate. The mortar is externally attached to the rear portion of the hull and lowered into position to be set along the ground at the vehicle rear, made ready to fire by the associated gunnery crew. Mortar projectiles are loaded via the breech as opposed to the muzzle as in infantry-level mortars. Up to 40 x 240mm projectiles were afforded the crew. There is a cupola aft of the driver's position along he hull roof that houses an access hatch and gun mount to which a 7.62mm PKT series machine gun can be affixed for anti-infantry defense.
The practice, the 2S4 has proven a devastatingly effective long-range weapon against many target types. The 240mm mortar holds a range of 9,650 meters and can manage various warhead types including standard high-explosive, fragmentation blast (287lbs) and armor-piercing types. As she was developed at the height of the Cold War, the 2S4 also has access to an inventory of chemical and nuclear-tipped projectiles as well but frequency of use concerning these projectile types is unknown. A precision-guided munition has also been noted with the 2S4 which broaden the tactical usefulness of the system considerably. This projectile type, known as "Dare Devil ("Smel'chak"), was developed during the Soviet involvement in Afghanistan and, on at least one occasion, proved its worth when engaging Mujahedeen targets that found themselves safely out of the capabilities of general Soviet field artillery. A rocket-assisted projectile can extend the "reach" of the 2S4 system as far out as 18,000 meters. As a mortar-class weapon, the 2S4 is capable of lobbing projectiles at enemy targets or known enemy positions, making her an indirect weapon type. If the 2S4 system has any limitations it is in her extremely disappointing slow-rate-of-fire, limited to just one round per minute and this due simply to the sheer size of each projectile. Additionally, the gunnery crew operates outside of the confines of the vehicle, exposing them to unnecessary battlefield dangers.
Only the Red Army and the Czech Army ever made use of the 2S4, and the latter was through very limited numbers - perhaps as little as four units. After the fall of the Soviet Empire, Red Army 2S4s then in inventory were simply passed on to the new Russian Army. Several hundred - as many as 425 - may still be in operational service today (2012). All Czech 2S4s were retired in sometime in 1991.
The Soviet Army inventory also designated their 2S4s as the "SM-240". The "Tyulpan" nickname translates to "Tulip Tree". During the Cold War, the nuclear capability inherent in the 2S4 saw her assigned to "High-Powered Artillery Brigades" charged with high-priority NATO targets.