TOS-1 is a Soviet 220mm 30-barrel (original system, Ob.634 or TOS-1M) or 24-barrel (Ob.634B or TOS-1A) multiple rocket launcher and thermobaric weapon mounted on a T-72 tank chassis. The TOS-1A heavy flamethrower system is designed for providing fire support to infantry and tanks, defeating enemy manpower from open and closed firing positions in a variety of offensive and defensive combat, as well as disabling light armored vehicles and transport. Combined target destruction is achieved through effects of high temperature and overpressure. TOS-1A was designed for defeating enemy personnel in fortifications, in open country, and in lightly armoured vehicles and transport. First combat tests took place in 1988–1989 in the Panjshir Valley during the Soviet war in Afghanistan. The TOS-1 was shown for the first time in public in 1999 in Omsk.
TOS-1A is not assigned to the artillery units of the Russian Armed Forces but is found in Russian CBRN defense units RKhBZ (Radiological, Chemical and Biological Defence Troops). That is why it does not have a GRAU index, but rather an RKhBZ index—МO.1.01.00.
The TOS-1A system includes:
BM-1 combat vehicle with a launcher mounted on tank chassis (1 unit);
TZM-T transporter/loader on tank chassis (2 units)
The system can be supplied with the TZM (563K) transporter/loader on an 8×8 off-road chassis. Unguided artillery rockets with thermobaric warheads are used for firing.
The BM-1 combat vehicle is a multiple rocket launcher mounted on a tank chassis. It is equipped with a fire control system, which includes: a laser periscope sight/rangefinder, digital dedicated computer system with a sensor package, power electro-hydraulic actuators and firing equipment. The BM-1 is also fitted with auxiliary systems and equipment (means of communication, observation instruments, NBC protection system, fire-fighting equipment, self-entrenching equipment, etc.).
The TZM-T/TZM (563K) transporter/loader is fitted with rocket cradles, a hydraulic loader crane, a removable ammunition armor kit, and loading facilities.
TOS-1s were first used in combat in Afghanistan’s Panjshir valley by the Soviet Union during the Soviet–Afghan War. Later, they were used during the Second Chechen War, prominently by the Russian Army during the Battle of Grozny in 1999. TOS-1As were first used in combat in Iraq by the Iraqi Army in the recapture of Jurf Al Sakhar on October 24, 2014 from ISIL forces. The Iraqi Army launched at least three TOS-1 rockets on 18 June 2017 during the first day of an offensive to recapture the Old City of Mosul, Iraq, from the Islamic State, targeting school buildings held by Islamic State forces and known to be devoid of civilians. The OSCE reported in September 2015 that the TOS-1 was sighted in a rebel training area in eastern Ukraine. The TOS-1 was used in Syria on October 10, 2015 by Syrian Army forces against rebel forces in Hama. In 2016 it was used against rebel forces in the Latakia mouintains. It was used again by the Syrian Army in April 2017 in the area of Palmyra, and later that same month to destroy an ISIS camp. Azerbaijan used the TOS-1A against the Nagorno-Karabakh Defense Army on April 4, 2016.