Part Two of this manual is for the guidance of operating personnel. It

includes information on the controls and on operation.

Section V SERVICE UPON RECEIPT OF EQUIPMENT

12. NEW EQUIPMENT.

Upon receipt of a new flame thrower, the following procedure should be carried out:

_a._ Cut packing-chest steel straps and seals with pliers.

_b._ Remove the screws, if present, from top of chest.

_c._ Open two latches at front of chest.

_d._ Lift lid backward and connect chain from inside of chest to inside of lid.

_e._ Remove moistureproof paper.

_f._ Remove gun from carton. After removing waterproofing tape from ends of hose, connect hose and gun. (Par 17)

_g._ Remove mounting board and place gun with hose on the board as shown in Figure 10.

[Illustration: Fig 11. Screwing deflector tube in safety head on left fuel tank.]

[Illustration: Fig 12. Controls for operation of portable flame thrower M2-2.]

_h._ Remove spare parts kit, tool kit, cans of ignition cylinders, and other items from packing chest.

_i._ Compare contents with packing list found in or on packing chest. Inspect all contents carefully for completeness, correct adjustment, and good condition.

_j._ Insert deflector tube in safety head on left fuel tank. (Fig 11) Outlet should face to rear and at a 45-degree angle to operator’s left shoulder. (Fig 18) Screw in deflector tube by hand; do not use wrench on deflector tube. Tighten lock nut with wrench.

_k._ Before use on a mission, test-fire the weapon. (Par 56 _b_)

_l._ Save the packing chest for storage of the equipment when flame thrower is not being carried on a firing mission or serviced.

13. USED EQUIPMENT.

When they apply, the same steps should be taken as in Paragraph 12. Any worn or damaged parts should be replaced. Areas where paint has worn off should be touched up with fresh paint.

Section VI CONTROLS

14. CONTROLS.

The firer uses the pressure-tank valve handle, the trigger, and the valve lever and grip safety (Fig 12) in succession as follows:

_a. Valve handle._ The pressure-tank valve is operated by turning a handle on the valve flexible shaft within reach of the firer. Counterclockwise operation of handle releases pressure to the fuel tanks. Clockwise turning closes the valve.

_b. Trigger._ The trigger is at the front grip of the gun. Pulling the trigger vigorously ignites an incendiary charge in the ignition cylinder. This in turn ignites the fuel as it leaves the gun. The trigger action also causes the ignition cylinder to revolve one-fifth of a turn, presenting another charge for firing. Each of the five charges may thus be used in rapid succession, if necessary, by pulling the trigger vigorously as many as five times.

_c. Valve lever and grip safety._ The valve lever and grip safety are mounted on opposite sides of the valve grip of the gun. When both controls are compressed, fuel is propelled from the gun. If either the valve lever or the grip safety is not compressed, the fuel valve remains closed and the fuel remains in the weapon.

Section VII OPERATION UNDER USUAL CONDITIONS

15. TRAINING.

Effective use of the M2-2 portable flame thrower can be achieved only by diligent practice with the weapon. Untrained firers or assistants should never be sent on a mission.

_a. Practice._ Firers should practice under varying conditions of wind, range, elevation, depression, and traverse. The shortness of the total firing time (approximately 8 to 9 seconds) demands split-second judgment and coordination.

_b. Use of water in training._ Water may be used (instead of fuel) for elementary practice firing. Ignition cylinders are not used with water. The water under pressure may cause serious injuries to personnel at 10 yards. After practice with water, the gun should be disassembled (Pars 73 through 76), cleaned and dried piece by piece, and lubricated. (Par 49)

_c. Use of fuel in training._ When using fuel in training, select or prepare a practice field of fire which provides at least 125 yards for range and 30 yards for spread. If the field contains dry grass, brush, or other flammable material, a fire-fighting squad should be available with equipment and source of water. Assistants and observers should stay well behind the firer because of danger from wind shifts. See Paragraph 40 for additional precautions.

16. CHARGING, FILLING, AND SERVICING.

Before use on missions or for training, flame throwers must be charged, filled, and serviced. Charging with compressed air or compressed nitrogen is described in Paragraphs 32 and 33; filling with fuel in Paragraphs 34 through 40; and servicing in Paragraphs 50 through 56. Test for pressure. (Par 53 _d_)

17. CONNECTING TANK GROUP AND GUN GROUP.

If a charged and filled tank group has been brought up to replace an emptied one:

_a._ Place the new tank group on the ground with the tank coupling on top. If the filling is thickened fuel, allow the tank group to rest in this position for from 1 to 2 minutes.

_b._ Remove coupling plug from new tank group and disconnect gun group from emptied tank group. Place unthreaded end of fuel hose in tank coupling and lock in place. (Par 70)

_c._ Lock the coupling plug in the emptied tank group.

18. LOADING WITH IGNITION CYLINDER.

_a. General._ Just before the start of a mission, load an unused ignition cylinder into the ignition head. (M1 and E1 ignition cylinders are identical and may be used interchangeably.) Cylinders are packed two to a can. Do not open cans until ready to load for a mission. The second cylinder in the can should be used in another flame thrower on the same mission or as soon as possible after opening the can. Partly used cylinders may be employed in training.

_b. Precautions._ Care must be taken, whenever cylinders are handled, to avoid any blows or pressure against the metal match ends. (Fig 13) Face, hands, and other parts of the body should never be exposed to front of cylinder or front of gun.

[Illustration: Fig 13. Ignition cylinder before use.]

_c. Procedure._ Loading procedure is as follows:

(1) Unscrew and remove ignition shield. (Fig 14)

(2) Place ignition cylinder on end of barrel (Fig 15), being careful not to grasp cylinder by its ends.

(3) Raise nozzle end of gun so cylinder slides down against the spring case of the ignition head. (Fig 16) If necessary, rotate cylinder so it slips down all the way. Do not force cylinder into place as forcing may prematurely ignite it.

(4) Rotate spring case and ignition cylinder clockwise as far as they turn freely.

(5) Place ignition shield over cylinder. Engage the slot in the shield on the spring-case pin.

(6) Turn shield, screwing it onto ignition-head body. Make sure the threads engage during the first turn of the shield. When the slot on the shield engages the latch on the ignition head (Fig 17), the gun is loaded.

(7) If shield cannot be turned by hand tight enough to engage latch, unscrew shield. Then turn shield backwards until threads engage and repeat (6) above.

[Illustration: Fig 14. Unscrewing ignition shield, with pressure on latch.]

[Illustration: Fig 15. Placing ignition cylinder on gun. Care must be taken to avoid striking or pushing metal matches of cylinder.]

[Illustration: Fig 16. Ignition cylinder in place on gun before replacement of ignition shield.]

[Illustration: Fig 17. Ignition head assembled for firing of gun.]

[Illustration: Fig 18. Tank group adjusted on firer.]

19. CARRYING THE TANK GROUP.

The tanks are supported on the firer’s back and secured to it by two shoulder straps and two pairs of body straps. (Fig 18) The straps may be adjusted by the buckles to fit the operator. The shoulder straps pass over the shoulders and under the arm pits; the lower body straps are clasped tightly in front of the body; and the upper body straps are clasped across the chest to prevent the shoulder straps from slipping and the tank group from rolling off the back. Adjustments to the various straps should be made until the unit is carried with the bottom of the fuel tanks at the small of the operator’s back. The tank group should fit snugly so that it does not shift if the operator changes position quickly.

20. CARRYING THE GUN.

[Illustration: Fig 19. Carrying the gun, with hands in position to fire.]

The procedure for carrying the gun is as follows:

_a._ Carry the gun with the hose at the right side. (Fig 19)

_b._ Grasp the valve grip with the right hand and the front grip with the left hand, being careful not to operate the controls until ready to fire.

_c._ Keep the gun pointed away from friendly personnel at all times.

_d._ Do not face the front of the gun at any time. Even when no fuel is being ejected, the incendiary charges of the ignition cylinder can cause severe burns.

_e._ Keep the gun dry and clean if possible. Avoid getting dirt or foreign matter into the weapon.

_f._ Avoid rough handling.

_g._ Wear gloves if available.

_h._ Carry any extra ignition cylinders only in metal containers.

21. OPENING PRESSURE-TANK VALVE.

The release of pressure into the fuel tank causes a hissing sound. Therefore, open the pressure-tank valve while still out of hearing range of the enemy. Do not, however, open it prematurely because of the possibility of pressure leaks. To prevent frothing of the fuel, keep the tank group in as nearly an upright position as possible when opening pressure-tank valve. Be sure to turn the valve handle all the way in a counterclockwise direction. Stiffening of the fuel hose occurs when the pressure-tank valve is opened.

22. RANGES.

Firers and assistants should learn to judge ranges by frequent practice under varying conditions. The firers should be trained to approach as close as practicable to the target and to fire if possible at point-blank range for the greatest results.

_a. Point-blank range._

(1) _Effects._ At very close (point-blank) range almost all of the burning fuel can be fired at great velocity directly through ports and openings into the target. Maximum casualties and damage are caused in the hostile position.

(2) _Protection._ Common sense precautions are taken to prevent casualties to friendly personnel from possible ricochet or rebounding of flame. If the target includes a vertical wall at a right angle to the firer or other friendly personnel, the weapon should not be fired at closer than 7 to 10 yards. When the weapon is fired at small openings in a bunker or pillbox, the firer and other members of the assault squad should not approach closer than 7 to 10 yards from the target.

_b. Other effective ranges._

(1) _Open fields of fire._ When thickened gasoline is used, portable flame throwers may fire with considerable effect as far as 40 yards under normal conditions, depending on wind direction and wind speed. Under the same conditions, liquid fuel maybe effective at 20 yards. Results and accuracy are not as great as at point-blank range.

(2) _Jungle or thick underbrush._ If the target is located in jungle or thick underbrush without cleared fields of fire, the effective range of the flame thrower is reduced by as much as one half, depending on the nature and density of the vegetation.

_c. Ineffective ranges._ Although the flame may reach considerably farther than the ranges stated in _b_ (1) above it may be useless because of the steep angle of descent and because much of the fuel is burned before it reaches the target.

23. WIND DEFLECTION.

Wind is an important factor because of the low velocity of the flaming fuel. Wind can lengthen, shorten, or deflect the flame.

_a. Head winds._ Head winds of more than 5 miles per hour tend to carry heat or even flame back toward the firer. Liquid fuel should not be fired into a head wind of more than 5 miles per hour. The range and accuracy of thickened fuels is reduced.

_b. Following winds or very light winds._ Best results are obtained under these conditions.

_c. Cross winds._ When firing at or near maximum range, cross winds deflect, breakup, and disperse the flame. They also reduce the range.

24. FIRING POSITIONS.

_a. Ease of aiming._ The flame thrower can be fired from any position that permits sufficient freedom to aim the weapon, subject to the conditions in _b_, _c_, and _d_, below. This includes standing, kneeling, and prone. In some instances, flame throwers have been fired with tank groups resting on the ground or on skids. If used in this way, the tops of the fuel tanks must be propped up to conform to _b_, below.

_b. Angles of the tanks._ When firing, the bottoms of the fuel tanks must always be substantially lower than the tops. The tops of both tanks must also each be the same distance above the horizontal and neither tank should be tilted to one side. Otherwise, only a small part of the fuel may be blown from the tanks.

_c. Recoil._ Stability must be sufficient to withstand the recoil from the gun. If possible, the firer should hold the gun snugly against his right side to support it and to absorb its recoil.

_d. Protection._ Full advantage should be taken of cover and concealment, such as shell craters and vegetation.

25. AIMING.

_a. Sighting._ There are no sights on the gun because of the short range from which it is fired, the variety of fuels used, and the marked effects of wind. (Par 23)

_b. Fortifications._ When firing at a fortified position, flame must be directed _into openings_ (gun ports, firing slits, ventilation screens, doorways). Flame inside gives the desired effects, but flame on the outside has little effect on personnel within.

_c. Thickened fuel._ (Figs 3 and 20) When firing at or near maximum range, it may take several seconds for a burst of thickened fuel to carry through the air to the target area. Short bursts may result in misses at long range for this reason. Skill in aiming is particularly important with thickened fuel.

_d. Liquid fuel._ With liquid fuel, the greatest effect may be obtained by placing the flame directly on the target. (Fig 21)

[Illustration: Fig 20. Thickened fuel flame hitting and clinging to target. Fuel burns for several minutes.]

[Illustration: Fig 21. Flame (liquid fuel) hitting target.]

26. FIRING.

With pressure-tank valve open:

_a. Pull trigger._ Pull the trigger rapidly and vigorously. A flash should appear at the front of the gun. This shows that an incendiary charge of the ignition cylinder has been ignited. Release the trigger. (If the flash does not appear, pull the trigger again, or as often as necessary up to five times, until a flash appears.)

_b. Squeeze fuel valve._ Immediately after pulling trigger, compress the valve lever and grip safety vigorously with the right hand. Burning fuel will be propelled from the gun.

_c. Adjust fire._ Direct the flaming fuel at the target. Continue to squeeze the valve lever and grip safety throughout the burst. When thickened fuel is fired, follow the fuel with eyes to the side of the stream in order to observe and correct aim. (If eyes are directly behind the stream, the flame may obscure the target.)

27. CEASING OR INTERRUPTING FIRE.

To cease or interrupt firing, release the controls.

28. ADDITIONAL BURSTS.

To fire additional bursts, repeat procedure followed in Paragraphs 26 and 27, keeping in mind that there are five incendiary charges in the ignition cylinder and that the total firing time, not including time between bursts, is approximately 8 to 9 seconds. Each of the five incendiary charges in the ignition cylinder burns for from 8 to 12 seconds.

29. SOAKING THE TARGET.

When liquid fuel is used, it may be desirable to soak the target with fuel first and ignite it afterward. To do this, fire one or two short bursts without pulling the trigger. Then follow with an ignited burst, as in Paragraph 26.

30. AFTER FIRING.

When the firer has returned from his mission, he should:

_a._ Remove and discard the ignition cylinder, as follows:

(1) Point gun at the ground.

(2) Press latch. (Fig 14)

(3) Unscrew the ignition shield and allow ignition cylinder to fall out. (Be careful to keep the hands away from the front of the cylinder.)

(4) Save the partly used cylinder for training use or destroy it by firing from gun after fuel tanks have been emptied. For information on care, handling, and storage of cylinders, see Paragraph 31.

_b._ Close the pressure-tank valve by turning valve handle clockwise (to conserve remaining pressure in pressure tank).

_c._ Point the gun away from personnel and blow out the remaining fuel, if any, from the fuel tanks by squeezing the valve lever and grip safety until there is no further discharge. The trigger should not be used during this operation.

_d._ Take off tank group from the back.

_e._ Inspect, clean, and maintain the flame thrower (Pars 55 and 56) or, if experienced maintenance personnel is close at hand, turn the weapon over to them for servicing.

_f._ After servicing, place the weapon in the packing chest (Par 77) for protected storage, or prepare it for the next mission. (Pars 50 through 53)

Section VIII AUXILIARY EQUIPMENT

31. IGNITION CYLINDER.

_a. Description and functioning._ (Figs 13 and 22) Either the M1 or E1 ignition cylinder may be used. It fits over the fore part of the barrel assembly and is revolved by the spring case. (Par 76) The five incendiary charges in the cylinder are spaced sufficiently far apart in the plastic body to prevent their igniting one another. Lead-foil seals, plastic closure plates, and waterproof cement make the unit comparatively waterproof.

[Illustration: Fig 22. Cutaway view of ignition cylinder (M1 or E1).]

_b. Action._ When the trigger rod is pushed forward, one of five metal matches tipped with red phosphorus scratches an igniting mixture. The ignition carries to a starter mix and to a few grains of black powder on top of the incendiary charge. The black powder blows the foil seal and closure plate clear of the flame thrower, and the incendiary charge ignites the fuel as it is discharged from the nozzle. The incendiary charge burns for from 8 to 12 seconds.

_c. Packing._ Ignition cylinders are packed two per waterproof can. Three cans are furnished with each flame thrower. Fifty cans (100 ignition cylinders) are contained in each packing box of extra cylinders.

_d. Care, handling, and storage._ Ignition cylinders contain hazardous incendiary material and must be handled with due care. The following precautions should be observed.

(1) _Opening cans._ Do not open cans containing cylinders until ready to load for a mission. (Par 18) If an extra cylinder remains in an opened can, use it as soon as possible. Any defective cylinders, such as those with damaged closure plates, should be destroyed. (Pars 30 and 46) Moisture may affect the cylinders and all possible care should be taken to avoid exposing them to dampness.

(2) _Handling cylinders._ Pressure on any of the five metal matches (Fig 13) may ignite an incendiary charge in the cylinder. Care must be exercised to avoid putting pressure on the projecting ends of the matches except when firing the weapon. Ignition cylinders and cylinder containers should be protected against shock. Boxes and cans containing cylinders must not be thrown or dropped.

(3) _Storing containers._ Containers of ignition cylinders are best stored in a dry, well-ventilated place, out of the direct rays of the sun, well protected against excessive temperatures. Smoking is not permitted and matches are not used where ignition cylinders are stored.

32. CHARGING PRESSURE TANK.

_a. General._ The pressure tank of the flame thrower must be fully charged with compressed air or compressed nitrogen before the start of a mission. For the M2-2 flame thrower, a pressure of at least 1,700 pounds per square inch is required. This may be provided either by the use of an air compressor capable of producing a pressure of at least 1,700 pounds per square inch, or by the use of commercial cylinders. The filling and charging lines from the service kit are used in conjunction with the cylinders. Before and after charging, follow the procedures described in Paragraphs 51 and 55.

_b. Charging from air compressor._ Compressor, air, gasoline engine driven, 7CFM, M1, is a self-contained, skid-mounted machine designed for use with flame throwers. It is capable of charging pressure tanks of flame throwers and large 200- or 220-cubic-foot commercial cylinders as well. Instructions for use of the compressor will be found in the manual accompanying it.

_c. Charging from cylinders._ If an air compressor is not available, it is necessary to use cylinders containing nitrogen or air.

(1) _Volume and pressure._ Cylinders come charged with 200 to 220 cubic feet of air or nitrogen. Since cylinders with 220 cubic feet of air or nitrogen have a higher initial pressure, it is recommended that they be procured, if obtainable. All cylinders used must have a pressure of at least 600 pounds per square inch. One or more of the cylinders must have a pressure of at least 1,800 pounds per square inch. Two or more cylinders, preferably at least four, should be used, if available.

(2) _Charging capacity._ Fully charged cylinders, if properly used in rotation, have capacity for charging pressure tanks approximately as follows:

1 cylinder (used alone) 2 pressure tanks 2 cylinders (in combination) 6 pressure tanks 4 cylinders (in combination) 24 pressure tanks 5 cylinders (in combination) 36 pressure tanks 6 cylinders (in combination) 48 pressure tanks

(3) _Apparatus._ The apparatus for charging two pressure tanks by the use of cylinders consists of a filling line, two charging lines, and two cylinders. (Fig 23) The filling line and charging lines are obtained from the service kit. (Par 48) Plugs are provided to close off either half of the filling line when only one flame-thrower tank group is to be charged.

(4) _Warning._ Oxygen is sometimes shipped in cylinders having the same threads as nitrogen cylinders. If oxygen not mixed with nitrogen, as in air, is introduced into the fuel tanks of the portable flame thrower, a violent explosion may result. Therefore, the greatest care must be exercised to see that only air or nitrogen is used. _Before a cylinder is connected, it should be tested to determine that it does not contain straight oxygen or some combustible gas._ This may be done by introducing a burning splint into a jet of the contents. Oxygen causes the splint to burn quickly, whereas nitrogen extinguishes the flame. To make the test:

(_a_) Fasten a thin splint of wood to a wire at least a foot long.

(_b_) Ignite the splint.

(_c_) Stand aside and hold it before the cylinder outlet.

(_d_) Crack the valve slightly to permit a small stream of gas to emerge.

(_e_) If the flame flares up, the gas is oxygen and _MUST NOT_ be used.

(_f_) If the gas itself catches fire, it may be hydrogen, acetylene, or some other combustible gas, which also must not be used.

(5) _Attaching lines to cylinders._ (Fig 23) The procedure for charging two flame thrower pressure tanks from two cylinders of nitrogen or compressed air begins as follows:

(_a_) Remove the valve-protection caps from the cylinders.

[Illustration: Fig 23. Charging two pressure tanks, using charging and filling lines, and cylinders of compressed air or nitrogen.]

(_b_) Place the cylinders side by side with both outlets facing in the same direction. (If the ground is not level enough for the cylinders to stand up side by side, lay them horizontally with both outlets face up.)

(_c_) Before attaching the filling line to the cylinders, blow out dust. (Par 33) Then connect, using wrenches to make the joints pressure tight. Do not kink or bend the flexible hose. Cylinders must be close enough together to prevent strain on the flexible hose.

(_d_) Attach a charging line to each of the two couplings on the filling line.

(6) _Attaching charging lines to pressure tanks._

(_a_) Close pressure-tank valves.

(_b_) Unscrew caps from check valves.

(_c_) Screw the charging-line fittings onto the check valves.

(_d_) Close bleeders.

(7) _Charging._ The operation of charging two pressure tanks from two cylinders is as follows:

(_a_) Close both filling-line valves.

(_b_) Open cylinder valves.

(_c_) Determine which cylinder has the lower pressure by the gages. Open the filling-line valve at the gage showing the lower pressure and fill the pressure tanks to the pressure shown by the gage. Close the valve. Then open the other filling-line valve and fill the pressure tanks until they reach pressures of at least 1,700 pounds per square inch as shown by the gage.

(_d_) When the pressure tanks have been filled, close the filling-line valves. Open the bleeders on the charging lines and leave them open until the pressure in the charging lines is released. Then close bleeders. Remove the charging-line fittings from the check valves. Screw the threaded caps on the check valves and tighten caps with a wrench.

(_e_) Repeat steps in (_a_) through (_d_) above for as many pairs of empty flame-thrower tanks as require charging.

(8) _To insure proper pressure._ Care should be taken to make certain that the compression delivered to the flame-thrower pressure tank is a full 1,700 pounds per square inch.

(_a_) If a filling-line valve leaks, tighten the packing nut on the valve with a wrench.

(_b_) When the higher pressure shown on the filling-line gages is less than 1,700 pounds per square inch, close the filling-line valve and the cylinder valve on the cylinder having the lower pressure. Remove and replace this cylinder with a fully charged cylinder. With chalk, mark the pressure on the cylinder which has been withdrawn.

(9) _After charging._ When charging has been completed:

(_a_) Close the filling-line valves. Observe the pressure indicated on each gage and mark the pressure on each cylinder using crayon, chalk, or pencil.

(_b_) Close the valves on the cylinders.

(_c_) Remove the charging-line fittings from the check valves, replace the threaded caps on the check valves, and tighten caps with a wrench.

(_d_) Remove the filling lines from the cylinders. Use two wrenches and take care not to twist or kink the flexible hose. Support the lines during the operation so that their full weight does not hang on the flexible hose during removal.

[Illustration: Fig 24. Arrangement of cylinders and lines for charging four flame throwers. Flexible hose (assembly E81-3-6) from service kit is used to connect two filling lines.]

(10) _Use of four-place lines._ (Fig 24) The filling and charging lines found in two or more service kits may be combined for more efficient charging of large numbers of pressure tanks. An additional flexible hose is provided in each service kit for connecting two filling lines. The procedure for charging is similar to that described above for the two-place line. Air or nitrogen is taken first from the cylinder with the lowest pressure and last from the cylinder with the highest pressure. See _a_ (2) above.

33. PRECAUTIONS WHEN PRESSURE-CHARGING.

Personnel will familiarize themselves with the following precautions:

_a. Handling._ Handle all cylinders and flame throwers carefully; never drop them and never subject them to shocks or blows. Keep valve-protection caps secured when cylinders are being handled, except when such handling is incident to the use of the nitrogen or air.

_b. Storage._ Keep all cylinders and charged flame throwers or tank groups (Par 77) in open or closed storage. They must, however, be protected from dampness and excessive rise in temperature caused by the direct rays of the sun or other source of heat. Avoid storing them near highly flammable substances, or in places where they may be struck by moving objects. Segregate empty cylinders to avoid confusion.

_c. Personnel._ Do not attempt to use compressed gases unless trained in this work. Use gases only for the purposes for which they are intended.

_d. Cylinder valves._ Do not tamper with safety devices in cylinder valves. If available, use the proper replacement parts for safety devices which are in need of repair. If such parts are not available, do not attempt to use makeshifts or nonstandard parts.

_e. Opening of valves._ Open valves slowly and fully each time nitrogen or compressed air is transferred from a cylinder. When a wrench is used, be sure it is one that fits properly, and that it is kept ready for instant use while the compressed gas is being released.

_f. Threads._ See that threads match before making connections. Some valves are provided with special threads which must be matched by the threads in the equipment being connected.

_g. Correct equipment._ Use gages, regulators, hose, pipe, and tubing of the type manufactured or specified for the particular apparatus or compressed gas.

_h. Repair._ Never attempt to alter or repair a cylinder.

_i. Flames and sparks._ Do not permit flames, sparks, or ignition from the flame thrower or other source to touch hose.

_j. Blowing out dust._ Immediately before coupling an attachment to the pressure tank or cylinder valve, open it for an instant to blow out any dust or dirt. Never stand where gas or dirt may be blown into the eyes or face. If the valve is difficult to open, apply more force gradually.

_k. Special devices._ Do not attempt to use any special connections or equipment without the approval of a qualified expert.

_l. Keeping valves closed._ Keep the valve of each cylinder closed when its contents are not actually being released from or admitted to the cylinder. This applies alike to all cylinders, whether they contain a compressed gas or are empty.

34. CHARACTERISTICS OF FUELS.

Thickened fuels give up to twice the range of liquid fuels. The stream of thickened fuel is comparatively narrow. Most of the glue-like fuel clings to and burns in or on the target for as long as 6 minutes. Liquid fuels, on the other hand, are largely consumed in flight to the target. If the location of small openings in the target is known, the stream of thickened fuel can be spotted by accurate aiming so that most of the fuel enters directly into the openings. While it does not billow around corners as does liquid fuel, thickened fuel strikes the target with force enough to ricochet inside. It clings to skin and clothing while burning. It also has excellent incendiary effects. The initial flame and smoke are less from thickened fuel than from liquid fuel, but the lower visibility, greater range, and much longer burning period of thickened fuel compensate for its smaller screening effect. Liquid fuels are easier to pour when filling than are thickened fuels.

35. PREPARATION OF THICKENED FUELS.

_a. Ingredients._ Thickened fuels consist of U.S. Army fuel thickener mixed with fuel.

(1) _Thickener._ U.S. Army thickener is supplied in airtight cans, each containing 5-1/4 pounds of the material.

(2) _Gasoline and fuel oil._ Gasoline alone is often used with thickener, but mixtures of gasoline and light fuel oil may be used satisfactorily. The light fuel oil can be either No. 1 fuel oil, No. 2 fuel oil, automotive diesel oil, or kerosene. These mixtures give more heat and do not form crusts. Except in hot climates, 75 percent or more of the mixture by weight or volume should be gasoline. (If too much light fuel oil is included, the fuel tends to separate into two layers.) In tropical theaters, a thickened blend of 50 percent gasoline and 50 percent light fuel oil has been reported to give favorable results. Storage qualities are not known, however. Another mixture which has been well recommended in field reports is 15 gallons of gasoline to 5 gallons of diesel fuel oil. Issue gasoline may be used, but locally procured gasolines which contain alcohol are not suitable.

_b. Proportion of thickener to fuel._ Less thickener is recommended than formerly. A low ratio of thickener gives a thickened fuel with many of the characteristics of liquid fuel. One can of thickener to 20 U.S. gallons of gasoline, or gasoline and light fuel-oil mixture, gives good results. This is a 4.2 percent by weight mixture. Except in hot weather, a fuel mixture of less than 3 percent thickener requires such long stirring that its preparation is impractical.

_c. Equipment._ An open-head 55-gallon or 42-gallon drum and an improvised wooden mixing paddle are used. Five-gallon cans may be employed to transfer the ingredients. The paddle should be approximately 5 feet long, 2 inches wide, and 1 inch thick. If a standard 55-gallon, open-head drum with an internal diameter of 27-7/16 inches is used, the improvised paddle should be marked to indicate gallons as follows:

_Gallons_ _Inches_ 40 23-1/2 20 11-3/4

Do not use a metal paddle because of the danger of striking a spark from the drum. Never use galvanized containers for mixing and storing thickened fuels. These may cause the fuel to break down and become excessively thin. An improvised funnel may be helpful in filling drums with prepared fuel for aging or transporting.

_d. Temperatures._

(1) _Below 50 degrees._ If the temperature is below 50 degrees Fahrenheit, it is helpful to prepare thickened fuel indoors, in a heated room. All precautions should be particularly observed. (Par 40)

(2) _Above 90 degrees._ When the fuel is hotter than 90 degrees Fahrenheit, the thickener reacts very rapidly. In this case, it is easier to prepare batches of 20 gallons each, but any number of batches may be prepared in succession.

_e. Moisture._

(1) _Effect of moisture._ Water in thickened fuel breaks down or reduces the viscosity of the gel and thereby reduces the range of the flame thrower. This effect may not be noticeable at once, but the stability of the fuel is affected.

(2) _Dryness of thickener._ Dry thickener is extremely hygroscopic, that is, it absorbs moisture from the atmosphere very rapidly. For this reason, thickener is shipped in hermetically sealed tin cans containing the exact quantity of powder required for mixing with 20 gallons of fuel to prepare a 4.2 percent mixture. It is important that the gasoline or fuel oil and gasoline be measured out before the thickener container is opened. The powder then should be poured immediately into the liquid.

(3) _Dryness of containers._ It is important that all containers used in mixing and handling the fuel be dry.

(4) _Keeping water out of gasoline._ Gasoline, especially when it has been stored in vented containers, frequently includes free water. Therefore, when using gasoline from a bulk-storage tank or an open drum, first place it in a clean, dry drum; allow it to stand quietly for at least an hour; then carefully pour off the gasoline from the top and discard the last gallon or two.

_f. Pouring and stirring._ (Fig 25) The liquid fuel is poured into the open drum; a pail or a paddle (Par 35 _c_) is used for measuring. One man then stirs the fuel vigorously. Another takes a can of thickener, splits it with a machete, bayonet, or ax, and pours it immediately into the fuel. Any large lumps of powder are broken by hand before the powder is added to the fuel. When mixing 40 gallons at a time, the two cans of thickener should be opened and added to the fuel in rapid succession. If the contents of the first can are permitted to gel before adding the second can, it will be difficult to obtain a uniform mix. Continue to stir.

[Illustration: Fig 25. Measuring fuel ingredient into mixing drum. Paddle for measuring and stirring is improvised.]

[Illustration: Fig 26. Transferring newly mixed thickened fuel from mixing drum to storage or shipping container for aging.]

_g. Examining fuel._ Lift the paddle quickly. If the mixture drops or runs from the paddle, additional stirring is necessary. When the paddle comes out clean, except for an adhering film, stirring should be stopped, provided there is no further visible

settling of particles of thickener.

_h. Loading shipping drums._ When stirring is completed, the mix is immediately bucketed (Fig 26) through a funnel into the shipping drum. The second bung hole should be open, if possible, to provide a vent to aid in pouring. Two men do the bucketing, each handling one pail so that the funnel may be kept loaded with mix and the shipping drum filled as rapidly as possible. Finally, the open-end drum should be picked up and its contents poured into the funnel. Not more than 50 gallons of thickened fuel should be loaded into a 55-gallon drum. The funnel should then be removed and replaced by a plug. The vent opening of the drum should also be closed. (See Paragraph 39 for pressure method of filling storage drums.)

_i. Unused thickener._ Any thickener remaining in opened cans should be discarded. Since moisture in the air can quickly ruin its properties, no attempt should be made to save it.

_j. Aging and storing._ Newly mixed fuel has the appearance of tapioca pudding. (Fig 27) It should preferably be stored overnight before use. It may, however, be fired within 1 hour after mixing. To keep fuel in good condition, drums for shipping and storing must be clean, moistureproof, dry, strong, and unrusted, but not galvanized. They must be kept tightly closed and should be laid on their sides so that rain water will not collect around the bungs.

_k. Testing fuel._ Before use on missions, all fuels should be tested by being fired from a flame thrower. This is advisable because the characteristics of the fuel ingredients often vary.

[Illustration: Fig 27. Contrasting newly mixed thickened fuel (right) with aged fuel (left).]

36. PREPARATION OF LIQUID FUELS.

_a. Choice of ingredients._ Thin fuels are easy to ignite, but they lack range and are largely burned in flight before reaching the target. For this reason, liquid fuels should contain the lowest proportion of gasoline and the highest proportion of heavier oils that permits easy ignition. In hot climates, less gasoline is needed than in cold climates. Exactness of proportion, however, is not of great importance. Suitable blends are as follows:

(1) Equal parts by weight or by volume of gasoline, light fuel oil, and heavy (bunker) fuel oil. The light fuel oil can be either No. 1 fuel oil, No. 2 fuel oil, automotive diesel oil, or kerosene.

(2) One part gasoline to four parts of cleaned crankcase drainings. (Par 36_e_) Unused motor lubricating oil can be employed in place of crankcase drainings, but usually it will be unavailable for flame-thrower use.

_b. Preparation of ingredients._ Before mixing blends, the following steps should be taken:

(1) _Gasoline, diesel oils, and fuel oils._ These fuel materials should be allowed to stand quietly for at least 30 minutes to permit any small quantity of water present to settle to the bottom. When transferring the fuel to another container, remove the fuel carefully so that no water is remixed with it.

(2) _Crankcase drainings._ If possible, crankcase drainings should be allowed to stand quietly in a container for at least 1 day. When pouring, take care to prevent the transfer of any of the sludge which may have settled in the bottom of the container.

_c. Equipment._ An open-head 55-gallon or 42-gallon drum and an improvised wooden mixing paddle are used. The paddle should be approximately 5 feet long, 2 inches wide, and 1 inch thick. A metal paddle should not be provided because of the danger of striking a spark from the drum. Five-gallon cans may also be furnished for measuring and transferring ingredients. Clean, unrusted, steel storage drums should be at hand. They should be at least 16-gage to have sufficient strength to withstand the internal vapor pressure of the fuel.

_d. Stirring._ All the ingredients should be stirred in the drum with the paddle until they appear to form a uniform mixture. This should require approximately 2 minutes.

_e. Crankcase-draining blends._ If crankcase drainings are used as an ingredient (Par 36_b_), it is preferable to allow the prepared mixture to settle for 24 hours after stirring, because the gasoline in the mixture may cause additional sludge to be deposited. Even after this settling period, it is recommended that the mixture be poured through cheesecloth or some similar fabric before the flame thrower is filled. Crankcase-draining blends should be allowed to stay in the flame thrower only long enough for completion of a mission, because additional sludge which may form from standing will clog the weapon.

_f. Transferring._ The mixture should be transferred either directly into the flame-thrower fuel tanks (Pars 37 through 40) or into storage drums. (Par 35_h_)

_g. Emergency mixing in fuel tanks._ In an emergency, mixing can be done in the flame-thrower fuel tanks by adding the ingredients in correct proportions and then shaking or stirring.

_h. Testing fuel._ Before fuel is used on a mission, it should be tested, if possible, by being fired from a flame thrower.

_i. Storage._ Fuels may be used immediately after preparation. If the blend contains crankcase oils, the fuel should be fired as soon as practicable after filling. Other liquid blends may be stored indefinitely until required for use. For storage precautions see Paragraph 40. The storage drums also should be kept tightly closed to prevent loss of gasoline through evaporation and to prevent moisture from entering the fuel. If stored in the open, the drums should be laid on their sides so that rain water will not collect adjacent to the bungs. An unrusted and undamaged 16-gage or 18-gage drum has sufficient strength to withstand the internal vapor pressure of the fuel.

37. FILLING BY POURING.

[Illustration: Fig 28. Filling fuel tanks by pouring. Any clean container may be used. A funnel may be improvised.]

(Fig 28) This method is the simplest and quickest for liquid fuel, but it may be too slow for some thickened fuels. The procedure is as follows:

_a._ Stand the tank group on the ground or a platform. If the tank group is not connected to the gun group, lock coupling plug in tank coupling. (Par 70)

_b._ Using a 1-3/4-inch wrench, unscrew the filling plug and the safety-head plug.

_c._ Inspect interior of tanks to see if clean and free from foreign matter. If not clean, flush with gasoline.

_d._ Using an improvised funnel, fill to within 2 inches of the top of both plug openings. This allows sufficient void. The tanks will then contain approximately 4 gallons of fuel.

_e._ Wipe the fuel-tank plug seats and the plug threads with a clean, dry cloth. (Fig 29) If plug has a tendency to freeze to seat, lubricate (Par 49 _b_) before screwing in the filling and safety-head plug assemblies. Tighten with wrench.

[Illustration: Fig 29. Wiping plug seat.]

_f._ Wipe any spilled fuel from weapon.

38. FILLING BY FORCE PUMP.

A force pump, if available, may be installed with a short length of pipe in the top opening of a drum of fuel for filling flame-thrower fuel tanks. Keep working parts of pump clean.

39. FILLING BY BLOWING.

Thickened fuel may be readily forced into the fuel tanks of flame throwers by the use of extremely low pressures of compressed air or nitrogen. Flame thrower fuel filling kit E6 or equivalent may be used. When equipment is available, filling by blowing is more efficient for filling large numbers of flame throwers with thickened fuel. Pouring or pumping are more time-consuming, depending on the consistency of the gel. The consistency may vary among batches even when the same proportion of thickener is used. The amount of moisture in the fuel seems to cause this variation. The precautions listed in Paragraph 40 should be observed.

[Illustration: Fig 30. Blowing thickened fuel into fuel tanks by use of cylinders of compressed air or nitrogen.]

_a. Source of pressure._ When the pressure in cylinders of compressed air or nitrogen has fallen too low to be of further use in filling pressure tanks of flame throwers, the remaining pressure may be used to blow fuel into fuel tanks if the regulator valve can reduce pressure down to 20 pounds per square inch. For precautions, see Paragraph 33. An air compressor or a hand air pump (tire pump) may be used in place of a cylinder if the latter is not available. Pressure of _no more than 15 to 20 pounds_ per square inch should be used on the fuel drums. Only a diaphragm-type regulator valve can be used safely. This valve must be capable of regulating any pressure that may be applied to it.

_b. Drums._ Clean, noncorroded, steel, 55-gallon drums should be used. Drums of United States manufacture which meet requirements will be stamped ICC-5 or ICC-5A, followed by three numbers in sequence, for example, “14-55-44.” The number “14” indicates the gage of the metal; “55” indicates the capacity in gallons; and “44” indicates the year of manufacture. A steel drum of 14 gage, or heavier, is preferable, but lighter drums (of 16 or 18 gage) may be used. Drums made of gages lighter than 18 gage (20-or 22-gage) must not be used. Drums should never be moved while under pressure.

_c. Connections._ The source of pressure (see _a_ above), the drum of fuel, the fuel-filling line, the air hose, and other parts, are connected as shown in Figure 30. Threaded adapters are used, as necessary, to fit lines to the drum. All threaded connections should be made tight by the use of wrenches on the joints. The drum and the pressure cylinder (if the latter is used) should be laid on their sides on the ground or a platform. The opening of the drum connected to the fuel-filling hose should be close to the ground or platform. If tank group is filled without gun group, lock coupling plug (Par 70) in tank coupling.

_d. Procedure._ To fill fuel tanks:

(1) Remove both the filling and safety-head plugs.

(2) Inspect interior of tanks to see if clean and free from foreign matter. If not clean, flush with gasoline.

(3) Place end of fuel-filling hose in either one of the two fuel-tank plug holes, using a nipple as a spout.

(4) Start air compressor or pump, or open the valve on the cylinder of compressed air or nitrogen. Open regulator valve on filling line by turning handle _slowly_ until gage shows 15 to 20 pounds pressure, but no more. _Caution_: “Cracking,” or opening a cylinder valve without using the proper regulator valve (Par 39 _a_), may result in explosive pressure in the drums.

(5) Both tanks must be filled to within 2 inches of their tops. Close valve on fuel-filling hose to halt flow at this level.

(6) If no additional flame throwers are to be filled, close pressure-cylinder valve, or stop compressor or pump. Then, using wrench, slightly loosen the air line at the drum, allowing pressure to bleed. When the pressure in the drum has fallen to that of the atmosphere, close regulator valve.

(7) Roll drum slightly and gently until fuel-filling hose is at top of drum.

(8) If there are valves on each end of the fuel-filling hose, use wrench to slightly loosen hose, allowing gradual escape of pressure. Stand away from, and at the side of, the connection. Keep hose pointed away from other personnel. When all pressure has been released, complete unscrewing of hose.

(9) Wipe fuel-tank plug seats and the plug threads with a clean, dry cloth. Then screw in filling plug and safety-head plug assemblies, applying grease (Par 49 _b_) if plug tends to freeze to seat. Tighten with wrench. Wipe any spilled fuel from weapon.

40. PRECAUTIONS WITH FUELS.

_a. Flammability._ All fuels used in flame throwers obviously are highly flammable and must be handled, stored, and used with extreme care. Diesel oil, fuel oil, and kerosene require the same care as does gasoline.

_b. Indoor storage._ When it becomes necessary to handle gasoline in a room or building, the windows and doors should be open and care taken that no unprotected flame which might ignite the fumes is in the vicinity. The doors and windows should remain open for a sufficient length of time afterward to allow any vaporized gasoline to escape.

_c. Flames and sparks._ The presence of open flames, heated stoves, electrical tools and apparatus, and other equipment likely to cause sparks must not be permitted. Even nails and metal cleats in shoes are a potential hazard in the presence of combustible fumes.

_d. Smoking._ “No Smoking” signs must be posted in prominent places about the premises and the rule against smoking must be strictly enforced.

_e. Ventilation and cleaning._ The buildings in which fuel is stored or used must be well ventilated and thoroughly cleaned every day. No rubbish or other flammable material should be permitted to remain in or near such buildings.

_f. Spillage._ Care should be taken that fuel is not spilled. Any spillage should be removed promptly.

_g. Safety cans._ Safety cans should be used, if possible, for storing small quantities of gasoline, as they have covers that must be forcibly held open to remove or add gasoline.

_h. Rags._ Metal receptacles with metal lids should be provided for discarded, oily, or gasoline-soaked rags. These rags must be disposed of daily.

_i. Electrical apparatus._ Vaporproof incandescent electric lamps, switches, and other appliances of approved type should be used. Open switches, relays, and similar apparatus, or motors with commutators, must not be used where gasoline fumes may be encountered.

_j. Hose._ Flexible metal, rubber, and rubber-metal hose should be inspected regularly (at least four times a year) and discarded when noticeably deteriorated.

_k. Toxic fumes._ Gasoline fumes are somewhat toxic and should not be inhaled.

_l. Leaks._ Leaks must never be neglected, and the fact that gasoline is a dangerous liquid must always be kept in mind. Inspections for leaks should be made frequently, particularly at pipe and hose joints.

_m. Fire extinguishers._ Carbon tetrachloride, carbon dioxide, or foam-type fire extinguishers should be provided and located where they will be accessible in the event of fire. Sand, not water, should be thrown on burning fuel if suitable extinguishers are not available.

_n. Leaded gasoline._ Gasoline often contains a poisonous lead compound. Such gasoline, or fuel containing leaded gasoline, should not be allowed to touch the body, especially the lips, eyes, open cuts, and sores.

Section IX OPERATION UNDER UNUSUAL CONDITIONS

41. WET CONDITIONS.

The M2-2 flame thrower may be carried and fired successfully in the rain or even after short immersion in water. After use when wet, it should be dried to prevent rusting, cleaned, and lubricated. (Pars 49 and 55) Areas where paint has worn off should be touched up with fresh paint. The weapon should be stored in a dry place. Moisture must not be allowed to enter fuel, ingredients of fuel, or containers of ignition cylinders.

42. DUST AND MUD.

Keep all possible dust, earth, and mud out of the flame thrower; particles may interfere with the operation of spring case, valves, bearings, and pressure regulator. Store weapons and auxiliary equipment in closed chests and boxes when not in use. (Par 77) Clean before use. (Pars 51 and 52)

43. HEAT.

A hot climate or exposure to the sun makes the fuel thinner when in containers. Thin fuel has shorter range; it is largely consumed in the air before it reaches usual effective ranges. Where the climate is torrid, less gasoline or other thinning agents should be used in a fuel blend than normally. (Pars 34 through 36)

44. COLD.

Cold weather reduces total heat produced at target but seldom enough to seriously lower value of a firing mission. Incendiary effects may be decreased because materiel is less flammable when cold. The weapon may be used at temperatures as low as minus 20 degrees Fahrenheit. To improve ignition, use more gasoline in fuel than normally. (Pars 34 through 36)

45. WIND.

Flame throwers should not be fired into strong head winds or across strong side winds. (Par 23)

Section X DEMOLITION TO PREVENT ENEMY USE

46. DESTRUCTION PROCEDURE.

If circumstances should force abandonment of chemical warfare materiel in the field, it is destroyed or rendered useless to prevent its use or study by the enemy. The following methods are recommended:

_a. Flame thrower._ One or more small-arms bullets through the fuel tanks will prevent any immediate use of the flame thrower. Additional rounds may be put through the pressure tank. If the pressure tank is charged, the pressure-tank valve should be opened for a few seconds, thus permitting the contents to dissipate. This is necessary if rounds are to be fired point-blank. The gun may be rendered useless by bending it over a hard object. A sledge or ax will demolish valves and tubes. A fragmentation grenade will also achieve demolition.

_b. Filling and charging apparatus._ The flexible tubing, gages, and valves may be destroyed by blows with an ax, sledge, or other heavy instrument. The large pressure cylinders are rendered useless by releasing the contents and then destroying the valves by blows with an ax or sledge. Cylinders can be stacked like cordwood in groups of five and demolished by the detonation of four 1/2-pound blocks (2 pounds) of TNT in their midst. The air compressor may be destroyed by a similar procedure.

_c. Fuel._ Burn.

_d. Mixing apparatus._ Containers and filling lines may be rendered useless by ax or sledge blows, or by small-arms fire.

_e. Thickener._ Cans of thickener should be broken open. Contents should be thrown into a fire or into a body of water.

_f. Ignition cylinders._ Burn to destroy. Personnel should stay several yards from the fire because the cylinders ignite with a slight detonation.

MAINTENANCE INSTRUCTIONS

Section XI GENERAL

47. SCOPE.