MANUFACTURER(S): State Factories - USA
OPERATORS: Australia; Brazil; Japan; Philippines; United States
ACTION: Rotary Cartridge Ignition Flame Jet
CALIBER(S)*: 4.7-gallon Nitrogen Fuel Canister
Detailing the development and operational history of the M2-2 / M9A1-7 Man-Portable Backpack Infantry Flamethrower.
Entry last updated on 9/26/2016.
Authored by Staff Writer. Content ©www.MilitaryFactory.com.
The M2 flamethrower (M2-2) served as the standard flamethrower of the US military during and after World War 2, replacing the M1 and M1A1 series. The M2 would go on to see service in the upcoming Korean and Vietnam wars and still play a role in today's modern military (used in field testing). Production of the M2 series was more than that of the M1 family and totaled nearly 25,000 examples.
It goes without saying that fire had always maintained a prominent place on the battlefield even dating as far back to ancient times. It was readily available and the only issue revolved around its adequate delivery onto the heads of enemy formations. "Liquid fire" was nothing new by the time of World War 1 and the Germans used such a flame-spewing weapons to good effect in the trenches against their French enemies. While these systems were large and cumbersome components, they instilled much fear against their intended targets in the fire zone and served as a tremendous psychological presence nonetheless - fire, it seemed, had a way of motivating any living thing to move from its held ground. By the time of the 1930s, the Germans had more or less perfected a man-portable backpack flamethrower (the "Flammenwerfer") that saw good use from it, leading to an ever-growing list of improved forms. It was only a matter of time that the Allies followed suit and developed their own serviceable models. For the Americans, the M1 became such a development - itself being loosely based on the original German design.
When the M1 was pressed into evaluation service by 1941, it was quickly shown to have some reliability issues in both design and operation. The system was hardly robust enough for the rigors of the battlefield and the ignition system - relying on hydrogen being ignited by the spark of a battery - often failed its users to the point that soldiers would use whatever means necessary to ignite the flame gun - burning bits of paper, cigarette lighters etc... The M1A1 was unveiled as an improved, more robust form in 1943 but the system still had a ways to go. Additives were now being added to the fuel stores to produce a "thicker" stream compound, increasing the weapon's range and damage cone. The weight was further "lightened" from 70lbs to make for a more portable system at 65lbs. However, the ignition system originating in the M1 remained unchanged in the M1A1, leading to some of the same problems during combat use.
Design of the M2 began in 1940 and continued on into 1941. With extensive use of the M1 and M1A1 systems, the Chemical Warfare Service - the group responsible for design and delivery of the original flamethrowers - used this experience to develop a more refined weapon system. The prototype came under the designation of "E3" and formed the basis of a new line of more robust and reliable flamethrowing systems. The experimental E3 was eventually accepted into service as the "Portable Flame-Thrower M2-2". The weapon system eventually entered service in 1943 and succeeded both the M1 and M1A1 when numbers made it possible. However, where it was not so, Army and Marine personnel continued use of the M1 family.
The M2 retained the same thickened fuel format as the M1 family but the biggest addition was the new cartridge-based ignition system. The old battery-actuated spark system was dropped from the design, instead replaced by a new five-shot, revolver-type magazine fitted to the end of the flame tube. Each revolver well held an ignition cartridge (for a total of five possible ignitions before reloading). The new system proved much more reliable under combat conditions than the original method, requiring reloading only after all five cartridges had been spent.
M2-2 / M9A1-7 (Cont'd)
Man-Portable Backpack Infantry Flamethrower
The M2 maintained an empty weight of 43lbs while she filled in at 68lbs when full of fuel and propellant. The weapon system could fire for up to a second for every half-gallon in the fuel store (or up to 7 seconds straight). Effective range was out to 65.5 feet while maximum spray range was 132 feet. Like the M1 and M1A1 before it, the M2 was worn like a backpack consisting of three tanks - 2 x gasoline tanks fixed vertically and 1 x Nitrogen propellant tank set between the twin fuel tanks. The mixture was fed to the flame gun by way of a tubing line. The flame gun was held with two hands as would a conventional combat rifle. The flame gun was essentially a pipe with a rear vertical handgrip having a controllable valve. The forend featured a pistol-grip style appendage with a ring-enclosed trigger controlling the ignition. The M2 was discernable from the M1 in that the M2's flame gun differed visually at the forward end and lacked the hydrogen canister fitted lengthwise on the gun. No sights were afforded the weapon and firing was generally "from the hip". Most photography showcases the operator down on one knee, which angled the flame gun upwards for a firing arc.
The M2 was soon to see action in 1944 on the island of Guam against the fanatical Japanese defenders. Deliveries were slow along some fronts to the extent that American forces in operating in Italy did not see arrival of the new flamethrower until March of 1945. The war in Europe would be over by June of that year with the Pacific Theater seeing closure in August. The M2 would see additional combat actions in the Korean War of 1950-1953.
The inherent dangers of operating a fuel-laden backpack flamethrower in open space were readily apparent with the M2. The operator still needed to expose at least his upper torso to enemy fire before he could squeeze a burst of flame fuel towards the enemy position. The enemy was quick to learn and began targeting flamethrower infantry as soon as they could be spotted. A single well-placed shot with incendiary ammunition held the possibility of igniting the fuel stores though standard bullets simply punctured the pressurized tanks and sent the operator flying. Conversely, American infantry soon learned to apply covering fire for their flamethrower brethren through standard infantry suppression tactics. Flamethrowers proved ever-popular in the Pacific Theater where their use was high when compared to that of European Fronts. They were adept at clearing out dry cover brush or flushing tunnels, bunkers and foxholes of hidden/dug-in enemies. Some Japanese infantry stood their ground and paid the terrible price of being burned alive while others surrendered at the sheer sight of an incoming M2 unit.
The M2A1-2 variant then became a modernized version of the World War 2-era M2 system and was pressed into service during the Korean War (1950-1953). The M2A1-2 was itself ultimately replaced by the time of the Vietnam War (1955-1975) by the M2A1-7 model which introduced the M7 flame gun. This line was then itself replaced by the newer, lighter M9A1-7 - the primary U.S. military flamethrower of the Vietnam War. The M9A1-7 was succeeded by the M202A1 "FLASH" ("Flame Assault Shoulder Weapon") of 1978.
Operators of the M2 system (and its related offspring) included the United States, Australia, the Philippines, Brazil and Japan. The Australians had begun work on an indigenous flamethrower design known as the "Ferret". After some of the American M2s were passed down to Australian ranks, design and development of the Ferret ceased in favor of the M2. Japan became a post-war user of the M2 family and featured it in their rebuilding army known as the Japanese Self-Defense Force (JSDF). The M2 was later replaced in Japanese service by an indigenous Japanese flamethrower system - though this system was itself based on the American M2 design.
The M2, as effective as it was, was never the final solution to the US Army need. As such, development of other experimental models continued throughout the war years. However, the end of the war pulled most military funding away and many projects under development died in the ensuing months of peace. Any improved man-portable flamethrower program would either be terminated, shelved for a time or forgotten altogether. Additionally, portable flamethrowers were generally dropped from some actions by the end of the war with the advent of flamethrowing tanks. These tanks were nothing more than existing tank chassis with specially-modified turrets housing a flame gun and applicable fuel stores. This arrangement allowed for even greater spray ranges while also affording the crew inside the protection of thick tank armor.