M1 flamethrower

M1A1 Flamethrower
M1A1 flamethrower being used against a Japanese bunker, March 1944.
Type	Flamethrower
Place of origin	United States
Service history
In service	1941–1945
Used by	United States Philippine Commonwealth Philippines
Wars	World War II
Production history
Designer	US Army Chemical Warfare Service
Designed	1940–41
Manufacturer	State Factories
No. built	13,886 (1,000 M1 & 12,886 M1A1)
Variants	E1, E1R1, M1, M1A1
Specifications
Weight	70 lb (31.8 kg) empty 70 lb (31.8 kg) filled
Crew	2
Rate of fire	~half a gallon a second
Effective firing range	65.5 ft (20 m)
Maximum firing range	141 feet (43 m)
Feed system	1 (4.7) Napalm infused gasoline tank (fuel) 1 Nitrogen tank (propellant)
Sights	None

The M1 and M1A1 were portable flamethrowers developed by the United States during World War II. The M1 weighed 72 lb, had a range of 15 meters, and had a fuel tank capacity of five gallons. The improved M1A1 weighed less, at 65 lb, had a much longer range of 45 meters, had the same fuel tank capacity, and fired thickened fuel (napalm).

Development of the weapon began in July 1940. The first prototype had the designation of E1. The prototype was further refined into the E1R1 model, which resulted in the adopted M1 model in August 1941. These man-portable weapons saw little use in Europe. They were more common in the Pacific, where they were used extensively when attacking pillboxes and fortifications. The M1's unreliability and lack of developed tactics resulted in the failure of the first flamethrower attack on a Japanese fortification in December 1942. The M1 was gradually replaced by the M1A1 in 1943. The M1A1 was replaced by the M2 flamethrower later during the war.

The M1A1 had a backpack configuration with a fuel tank that consisted of two upright bottles. A third, smaller upright bottle, the propellant tank, was located between the fuel tanks. The backpack had a high-pressure valve. The nozzle of the weapon was located at the end of a long, thin pipe, which was connected to the backpack via a hose. The pipe was slightly bent at the nozzle end. The nozzle had a hydrogen-powered ignitor. The long and thin cylindrical hydrogen tank was attached parallel to the pipe. A battery provided the spark needed to ignite the hydrogen. The hydrogen flame then ignited the fuel, which was forced out of the fuel tank through the hose and out of the nozzle by the propellant pressure when a valve was opened. The valve lever was located at the other end of the pipe, at the junction of the hose and the pipe.

World War I saw the initial deployment of flamethrower systems. The Germans fielded the Kleinflammenwerfer and Wex flamethrower unit to complement its specialist battalion stormtrooper units and tactics. Used first in a battle on July 30, 1915 at Hooge in Flanders, the Germans surprised the British and French forces in an assault that inflicted almost 800 casualties. The British and French responded in kind with the fielding of flamethrower systems copied from the Germans. Initial uses of the weapon startled opposing forces, but tactics were developed to counter flamethrower elements including concentrated fire on known flamethrower positions and keeping safe distances.
The arrival of the Americans in December 1917 provided American troops with first hand experience in the fielding of flamethrower systems. The Americans experimented with and developed flamethrower systems during the war, but were curtailed by the signing of the armistice. The previously aforementioned tactics against their deployment and the extreme danger of the flamethrower system contributed to the American forces regarding it as a total failure. General Amos A. Fries, chief of the Chemical Warfare Service (CWS) department from 1920 to 1929, of the American Expeditionary Forces commented that flamethrowers were: "one of the greatest failures among the many promising devices tried out on a large scale in the war." The American perception of the system as a failure in the interwar years saw no research or development of flamethrowers. The assessment ran counter to other nations and reappeared in the Abyssinian war of 1935-1936 and the Spanish Civil War.
In the blitzkrieg efforts of the Germans in the years of 1939 and 1940, intelligence reports of German troops utilizing flamethrower equipment circulated. The efficacy of the blitzkrieg and deficiency of corresponding flamethrower capability prompted the secretary of war to charge the CWS on August 12, 1940 to develop a flamethrower system.