When the Soviets discovered the value of battlefield rockets in saturating entire areas during the fighting of World War 2 (1939-1945) it became impossible for the Red Army to give up use of such valuable systems. This led to a progressive line of "rocket projectors" witnessed through the entirety of the Cold War years (1947-1991), each design improving on battlefield effectiveness. These rocket projectors were exported in the thousands to Soviet-allied nations and states, ultimately seeing combat service in a plethora of regional conflicts for their ease-of-operation, contained training and maintenance requirements, and low-cost procurement.
The BM-14 ("Boyevaya Mashima" = "Combat Machine") carried on the Soviet tradition of a rocket-projecting truck (the classic truck form still being the BM-13 "Katyusha" of World War 2 fame). It appeared in 1952 and sported a conventional design arrangement - the engine at front of the protected driver's cab and the launcher unit sat over the flatbed section of the truck. 4x4 wheeled drive was offered for cross-country mobility, playing to the strengths of Soviet doctrine largely influence by its actions against the Axis in World War 2. Design work on the BM-14 was had through NII 303 and began in the early 1950s.
The launcher unit, available in either a 16- or 17-shot count, featured the 140mm M-14 rocket. These were completed with High-Explosive, FRAGmentation (HE-FRAG) warheads for maximum destruction of a given target area. Alternatively, rockets were made to deliver a chemical-based payloads (M-14-S) or the white phosphorous smoke-generating payloads (M-14-D). Range of each rocket was out to six miles and the attack angle was indirect Line-of Sight (LoS) - the launcher rail unit given inherent elevation and traverse functionality.
The initial model of 1952 became BM-14 (Soviet Army designator of "8U32") which presented the 16-shot launcher unit fitted atop the rear sections of ZiS-151 service trucks (they were also known under the designation of "BM-14-16"). Then came a modified form using the ZiL-157 truck as the BM-14M (2B2) and its final evolution served as the BM-14MM (2B2R), these relying on ZiL-131 trucks. A towed version was revealed as the "RPU-14" (8U38) and designed with Soviet airborne troopers in mind - portability being a key quality. These sat the launcher units on the existing twin-wheeled carriages of D-44 field guns with the sixteen launch tubes arranged in a 4x4 collection.
The Polish Army adopted a similar towed weapon in the 140mm "WP-8z" but these were given only eight launch tubes. It arrived in the middle part of the 1960s and fewer than twenty were believed made. The "Type 63" of 130mm caliber was another BM-14-related towed model though of Chinese origin and fitted to the flatbed sections of Nanjing NJ-230/230A trucks - these being nothing more than licensed copies of the Soviet GAZ-63/63A. The launcher component held nineteen shots.
The BM-14-17 (8U35) brought along use of a 17-shot launcher component and these were coupled to the GAZ-63A series trucks. Development was in the late 1950s and the launcher units were also featured on several Soviet Navy ship designs.
The BM-14 was taken on by the Soviet Army as well as many allies ranging from Algeria and Angola to Vietnam and Yemen. Soviet use was ended with the fall of the Soviet empire in 1991 and these existing stocks fell to successor states including Russia itself.
BM-14 systems went on to see extensive combat service through such conflicts as the Algerian Civil War (1991-2002), the Dhofar Rebellion (1962-1876), the War in Afghanistan (2001-2014) and the Syrian Civil War (2011-Present). Largely inaccurate (a common failing of many early Cold War-era rocket projectors), the weapons proved their worth through simple target area saturation. They carried an inherent lethality that basic artillery could not replicate and served as a psychological tool against the minds of troopers unfortunately enough to be caught under a salvo.
BM-14 systems were replaced in the Soviet inventory (at least partially) by the newer BM-21 "Grad" models of 1963. Many of these remain in service with global operators as well.