Flamethrower

A flamethrower is a ranged incendiary device designed to project a controllable jet of fire. First deployed by the Byzantine Empire in the 7th century AD, flamethrowers saw use in modern times during World War I, and more widely in World War II as a tactical weapon against fortifications.

Most military flamethrowers use liquid fuel, typically either heated oil or diesel, but commercial flamethrowers are generally blowtorches using gaseous fuels such as propane. Gases are safer in peacetime applications because their flames have less mass flow rate and dissipate faster and often are easier to extinguish.

Apart from the military applications, flamethrowers have peacetime applications where there is a need for controlled burning, such as in sugarcane harvesting and other land-management tasks. Various forms are designed for an operator to carry, while others are mounted on vehicles.

Modern flamethrowers were first used during the trench warfare conditions of World War I and their use greatly increased in World War II. They can be vehicle-mounted, as on a tank, or man-portable.

The man-portable flamethrower consists of two elements—the backpack and the gun. The backpack element usually consists of two or three cylinders. In a two-cylinder system, one cylinder holds compressed, inert propellant gas (usually nitrogen), and the other holds flammable liquid, typically some form of petrochemical. A three-cylinder system often has two outer cylinders of flammable liquid and a central cylinder of propellant gas to maintain the balance of the soldier carrying it. The gas propels the liquid fuel 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 of 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.

Flamethrowers were 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 unseen spaces, such as inside bunkers or pillboxes. Typically, popular visual media depict the flamethrower as short-ranged and only effective for a few metres (due to the common use of propane gas as the fuel in flamethrowers in movies, for the safety of the actors). Contemporary flamethrowers can incinerate a target some 50–100 metres (160–330 ft) from the operator; 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 the weapon's weight and length, which impairs the soldier's mobility. The weapon is limited to only a few seconds of burn time, since it uses fuel very quickly, requiring the operator to be precise and conservative. Flamethrowers using a fougasse-style explosive propellant system also have a limited number of shots. The weapon is very visible on the battlefield, which causes operators to become immediately singled out as prominent targets, especially for snipers and designated marksmen. Flamethrower operators were rarely taken prisoner, especially when their target survived an attack by the weapon; captured flamethrower users were in some cases summarily executed.

The flamethrower's effective range is short in comparison with that of other battlefield weapons of similar size. To be effective, flamethrower soldiers must approach their target, risking exposure to enemy fire. Vehicular flamethrowers also have this problem; they may have considerably greater range than a man-portable flamethrower, but their range is still short compared with that of alternative weapons.