A flamethrower is a mechanical device designed to project a long controllable stream of fire.
Some flamethrowers project a stream of ignited flammable liquid; some project a long gas flame. Most military flamethrowers use liquids, but commercial flamethrowers tend to use high-pressure propane and natural gas, which is considered safer. They are used by the military and by people needing controlled burning capacity, such as in agriculture (e.g. sugar cane plantations) or other such land management tasks.
The flamethrower is in two elements: back pack and gun. The backpack element usually consists of two or three cylinders. One cylinder holds compressed, inert propellant gas (usually nitrogen), and the other two hold flammable liquid - typically petrol with some form of fuel thickener added to it. A three-cylinder system often has two outer cylinders of flammable liquid and a central cylinder of propellant gas to improve the balance of the soldier who carried it. The gas propels the fuel liquid out of the cylinder through a flexible pipe and then into the gun element of the flamethrower system. The gun consists of a small reservoir, a spring-loaded valve, and an ignition system; depressing a trigger opens the valve, allowing pressurized flammable liquid to flow and pass over the igniter and out the gun nozzle. The igniter can be one of several ignition systems; a simple type is an electrically-heated wire coil, another used a small pilot flame, fueled with pressurized gas from the system.
The flamethrower is a potent weapon with great psychological impact upon unprepared soldiers, inflicting a particularly horrific death i.e. being burnt alive. This has led to some calls for the weapon to be banned. It is primarily used against battlefield fortifications, bunkers, and other protected emplacements. A flamethrower projects a stream of flammable liquid, rather than flame, which allows bouncing the stream off walls and ceilings to project the fire into blind and unseen spaces, such as inside bunkers or pillboxes. Typically, popular visual media depict the flamethrower as short-ranged, of a few effective meters (due to the common use of propane gas as the fuel in flamethrowers in movies, for the safety of the actors), but contemporary flamethrowers can incinerate targets at 50–80 meters (165–270 feet) distance from the gunner; moreover, an unignited stream of flammable liquid can be fired and afterwards ignited, possibly by a lamp or other flame inside the bunker.
Flamethrowers pose many risks to the operator. The first disadvantage is its weight, which impairs the soldier's mobility. Flamethrowers are very visible in the battlefield, and so operators become prominent targets for snipers. Historically, flamethrower operators were rarely taken prisoner, especially when their targets survived the impacts of the weapon; in reprisal, captured flamethrower users often were summarily executed. Finally, the flamethrower's effective range is short in comparison with that of other battlefield firearms, i.e. for effective use, flamethrower soldiers must approach their targets closely, risking exposing themselves to close enemy fire.
The risk of a flamethrower soldier being caught in the explosion if enemy gunfire hits the flamethrower is exaggerated in Hollywood films.
It should be noted that flame thrower operators did not usually face a fiery death from the slightest spark or even from having their tank hit by a normal bullet as often depicted in modern war films. The Gas Container [i.e. the pressurizer] is filled with a non-flammable gas that is under high pressure. If this tank were ruptured, it might knock the operator forward as it was expended in the same way a pressurized aerosol can bursts outward when punctured. The fuel mixture in the Fuel Containers is difficult to light which is why magnesium filled igniters are required when the weapon is fired. Fire a bullet into a metal can filled with diesel or napalm and it will merely leak out the hole unless the round was an incendiary type that could possibly ignite the mixture inside. This also applies to the flame thrower Fuel Container.''
The best way to minimize the disadvantages of flame weapons was to mount them on armoured vehicles. The Commonwealth and the United States were the most prolific users of vehicle mounted flame weapons; the British and Canadians fielded the Wasp (a Universal Carrier) at the infantry battalion level, beginning in mid 1944, and, eventually, incorporating them to infantry battalions. Early tank-mounted flamethrower vehicles included the 'Badger' (a converted Ram tank) and the 'Oke', used first at Dieppe; the most famous flame tank was the Churchill Crocodile.
The Pen Huo Qi (Fire Throwing Machine) was a Chinese piston flamethrower that used a substance similar to gasoline or naphtha, invented around 919 AD during the Five Dynasties and Ten Kingdoms period. Advances in military technology aided the Song Dynasty in its defense against hostile neighbors to the north, including the Mongols. The earliest reference to Greek Fire in China was made in 917 AD, written by the author Wu Ren-chen in his Shi Guo Chun Qiu. In 919 AD, the siphon projector-pump was used to spread the 'fierce fire oil' that could not be doused with water, as recorded by Lin Yu in his Wu Yue Bei Shi, hence the first credible Chinese reference to the flamethrower employing the chemical solution of Greek fire. Lin Yu mentioned also that the 'fierce fire oil' derived ultimately from China's contact in the 'southern seas', Arabia (Dashiguo). In the Battle of Langshan Jiang (Wolf Mountain River) in 932, the naval fleet of the Wenmu King of Wuyue defeated the fleet of the Kingdom of Wu because he had used 'fire oil' (huo yóu, 火油) to burn his fleet; this signified the first Chinese use of gunpowder in warfare, since a slow-burning match fuse was required to ignite the flames. The Chinese applied the use of double-piston bellows to pump petrol out of a single cylinder (with an upstroke and downstroke), lit at the end by a slow-burning gunpowder match to fire a continuous stream of flame (as referred to in the Wujing Zongyao manuscript of 1044 AD). In the suppression of the Southern Tang state by 976 AD, early Song naval forces confronted them on the Yangtze River in 975 AD. Southern Tang forces attempted to use flamethrowers against the Song navy, but were accidentally consumed by their own fire when violent winds swept in their direction. Documented also in later Chinese publications, illustrations and descriptions of mobile flamethrowers on four-wheel push carts appear in the Wujing Zongyao, written in 1044 AD (its illustration redrawn in 1601 as well).
Although flamethrowers were never used in the American Civil War, the use of Greek Fire was threatened, and flamethrowers have been in use in most modern conflicts since then.
The English word 'flamethrower' is a loan-translation of the German word Flammenwerfer, since the modern flamethrower was first invented in Germany. The first flamethrower, in the modern sense, usually is credited to Richard Fiedler. He submitted evaluation models of his Flammenwerfer to the German army in 1901. The most significant model submitted was a man-portable device, consisting of a vertical single cylinder 4 feet (1.2 m) long, horizontally divided in two, with pressurized gas in the lower section and flammable oil in the upper section. On depressing a lever the propellant gas forced the flammable oil into and through a rubber tube and over a simple igniting wick device in a steel nozzle. The weapon projected a jet of fire and enormous clouds of smoke some 20 yards (18 m). It was a single-shot weapon - for burst firing, a new igniter section was attached each time.
It was not until 1911 that the German army accepted their first real flamethrowing device, creating a specialist regiment of twelve companies equipped with Flammenwerferapparaten. Despite this, the weapon went unused in World War I until February 26, 1915, when it was briefly used against the French outside Verdun. On July 30, 1915, it was first used in a concerted action, against British trenches at Hooge, where the lines were just 4.5m (5 yards) apart - even there however, the casualties were mainly from soldiers being flushed into the open and shot by normal weapons rather than from the fire itself.
The weapon had other drawbacks: it was cumbersome and difficult to operate and could only be safely fired from a trench, so limiting its safe use to areas where the opposing army trenches were less than the maximum range of 18m (20 yards) apart - which was not a common situation and made their use ineffective (in addition to the fuel lasting for only 2 minutes).
Nevertheless, the German army continued deploying flamethrowers during the war in more than 300 battles, usually in teams of 6 flamethrowers.
The flamethrower was extensively used during World War II. In 1940, the Wehrmacht first deployed man-portable flamethrowers against Dutch gun emplacements and fortifications. Subsequently, in 1942, the U.S. Army introduced its own man-pack flamethrower.
WWII German army flamethrowers tended to have one large fuel tank with the pressurizer tank fastened to its back or side. Some WWII German army flamethrowers occupied only the lower part of its wearer's back, leaving the upper part of his back free for an ordinary packful of supplies.
As the Third Reich was deteriorating at the end half of World War II, a smaller compact flamethrower known as the Einstossflammenwerfer 46 was produced due to the lack of materials and funds.
The ROKS-1 flamethrower was a stationary device used for the defense of strongholds. It could rather be categorised as a projecting incendiary mine. Different from the LPO and TPO flamethrowers the ROKS had only one cylinder with fuel.. The November 1944 issue of the US War Department Intelligence Bulletin refers to 'Fougasse flame throwers' used in the Russian defence at Stalingrad being the basis of a German version found in Italy that were buried with a fixed direction discharge tube and integrated with conventional landmines and barbed wire in defense works. The German weapon had an 8 gallon fuel tank and the seven in the installation were wired back to a control point and could be fired individually or all at once.
Unlike the flamethrowers of the other powers during World War II, the Soviets were the only ones to consciously attempt to camouflage their flamethrowers, The ROKS-2 flamethrower which was done by disguising the "gun" as a standard issue rifle, such as the Mosin Nagant, and the fuel tanks as a standard infantryman's rucksack, to try to stop snipers from specifically targeting flamethrower operators.
The British hardly used their man-portable systems, relying on Churchill Crocodile tanks in the European theatre. These tanks proved very effective against German defensive positions, and caused official Axis protests against their use. There are documented instances of German units executing, out-of-hand, any captured British flame tank crews.
Flamethrowers have not been in the U.S. arsenal since 1978, when the Department of Defense unilaterally stopped using them. They have been deemed of questionable effectiveness in today's combat and use of flame weapons is always a public relations issue due to the horrific death they inflict. They are not banned in any international treaty the U.S. has signed. Thus, the US decision to remove flamethrowers from its arsenal is entirely voluntary.
The USSR developed a rocket launcher specifically for the deployment of incendiaries - the ΡΠΟ-80 (RPO) or Rocket-launched Infantry Flamethrower. It has similarities to the famous RPG rocketlaunchers but the warhead is much bigger (approx. 2-3 liters Napalm) thus reducing the effective range.
In California, unlicensed possession of a flame-throwing device — statutorily defined as "any non-stationary and transportable device designed or intended to emit or propel a burning stream of combustible or flammable liquid a distance of at least 10 feet" H&W 12750 (a) — is a misdemeanor punishable with a county jail term not exceeding one year OR with a fine not exceeding $10,000 (CA H&W 12761). Licenses to use flamethrowers are issued by the State Fire Marshal, and he or she may use any criteria for issuing or not issuing that license that he deems fit, but must publish those criteria in the California Code of Regulations, Title 11, Section 970 et seq.
The book Breath of the Dragon: Homebuilt Flamethrowers, by Ragnar Benson describes homebuilt construction of flamethrowers for private ownership.
Flamethrowers were used against Africanized honey bee (killer bee) swarms in the 1970s.
Hollywood seems to have no difficulty getting hold of flamethrowers; however, for the safety of the actors, they often are filled with propane gas instead of liquid fuel. This produces a visually similar (though rarely identical) flame effect, but without the spray of fuel, splatter of flame, dense smoke, and area effect of the genuine fuel. In the Omaha Beach sequence of Saving Private Ryan, the exploding flamethrower was filled with enough propane gas to burst the containers and produce spectacular flames. The explosion seen occurred seconds after the tank burst - it was caused by blowing vaporized propane onto the explosion (the cloud is visible in the finished film as a billowing white cloud in front of the actor).
Flamethrowers are also used for special effects, such as concerts and special events; particularly, the band Rammstein's lead singer Till Lindemann is known to use a flamethrower during live performances.