4. CHARACTERISTICS AND EMPLOYMENT.
a. Action. Fuel is propelled into the target by a charge of highly compressed air or nitrogen. As fuel leaves the gun of the M2-2 portable flame thrower ([Fig 1]), it is ignited by contact with flame from charges of incendiary mix held in an expendable ignition cylinder.
b. Bursts. A continuous stream or separate bursts may be fired for approximately 8 to 9 seconds, not including time between the bursts. The five incendiary charges in the ignition cylinder are controlled by the trigger and can ignite several bursts.
c. Range. Portable flame throwers are fired at extremely close or point-blank range for best results. ([Par 22]) Effective range for liquid fuels ([Fig 2]) is as far as 20 yards, and for thickened fuels ([Fig 3]), 40 yards, but underbrush and adverse winds can reduce the distances.
d. Weight. To keep the weight as light as possible and still provide strength to withstand very high pressures, most parts are made of aluminum or sheet steel.
e. Tactics. Two or more flame throwers are generally used on a mission with other weapons of the assault squad. (See FM 31-50, “Attack on a Fortified Position and Combat in Towns.”)
f. Firers and assistants. One man carries and fires each flame thrower. Well-armed assistants accompany firers to give close protection and to serve as emergency replacements. Whereas the M1A1 portable flame thrower may require the help of an assistant to open the pressure-tank valve, the M2-2 flame thrower pressure-tank valve is located within reach of the firer and is operated by him without assistance. Firers and assistants should be thoroughly trained in operation of the weapon.
Fig 4. Tank group.
g. Charging and filling. In order to replace pressure tanks (cylinders) of earlier types of flame throwers, it is necessary to unscrew and screw threaded connections. Experience has shown that this frequently resulted in damage to threads, leakage, loss of pressure, and loss of range. It is also necessary to use tools to replace each pressure tank (cylinder). The design of the M2-2 flame thrower eliminates these difficulties. The tank group ([Fig 4]) may be charged and filled as a unit with or without gun and hose. The quick-connecting tank coupling permits rapid interchanging of empty and full tank groups by the firers or assistants. This is done without tools, takes very little time, and cannot cause leakage, loss of pressure, and loss of range due to damaged threads.