The flamethrower was used as an attempt to end the trench warfare on the western front. Flamethrowers were mostly used for physiological terror as their amount inflicted casualties was very low. The flamethrower was basically a nozzle that was connected with a rubber hose to one or more fuel tanks. The pressure from the tank would release the flammable liquids.
Grossflammenwerfer
This was the first flame thrower made by Richard Fiedler. It was a larger version of the kleinflammenwerfer and could throw flame twice as far (40 yards). It was a stationary flamethrower with multiple fuel tanks. These could throw flame about twice as far as the kleinflammenwerfer. They were used to discourage attacks on trenches.
Kleinflammenwerfer
The kleinflammenwerfer first saw action in a surprise attack on British troops at Hooge in Flanders on 30 July. The attack took place at 3:15 am and drove the terrified British from their trenches. The flammenwerfers were then adopted for official German military service. The kleinflammenwerfer was used in groups of six with two men on each device.
Livens Large Gallery Flame Projector
The British flamethrower named after it's inventor,William Howard Livens . Four Livens Large Gallery Flame Projectors were built in No Man's Land only about 60 yards from the German lines during the Somme offensive in July 1916. The Germans caught on to the movement before them and took two flamethrowers out of service with artillery fire. The flamethrower was 56 feet long, weighed 2.5 tons, and took 300 men to move. It had a range of 90 yards.
Wechselapparat
The Wechselappart was created to replace the heavy Kleinflammenwerfer. It also included a self-ignition system.
The Schilt Portable Flamethrower
A French version of the Kleinflammenwerfer. It was lighter and superior in quality. The Schilt was used shortly from 1917-1918 for trench attacks.
Flamethrowers Today
Modern flamethrowers can now reach out to about 100m, but they were dropped from United States military service in 1978.