Practical Training for Auxiliary Firemen
Third of a Series of Articles Devoted to This Important Phase of National Defense
IN this, the third of the series of articles on the training of auxiliary firemen, various types and sizes of incendiary bombs are discussed, together with methods of extinguishing fires incidental to these bombs.
The following installment will discuss the fighting of incipient fires resulting from incendiary bomb attacks.
Questions and Answers
Q. Is it safe to move magnesium incendiary bombs while they are still burning?
A. Yes, if they are not of the explosive type.
Q. What appliances or equipment are commonly used in connection with the removal of burning bombs?
A. Long handled shovel (scoop), tongs, sand pails and sand, snuffer, heavy gloves, blanket (wetted), and goggles.
Q. What procedure is followed in removing burning bombs?
A. First, make sure that the bomb is not of the explosive type by waiting behind protection for about two minutes after arrival of the bomb. After this period has elapsed, the bomb is covered with sand to check glare and slow down rate of burning, and then shovelled up and placed in metal pail (bucket) partly filled with sand. Sand from floor may be replaced in bucket to cover bomb. The pail containing bomb is then carried to place of bomb disposal.
Q. What is best method of carrying the pail containing the burning bomb?
A. With a shovel handle or pole through bail of pail to enable the pail to be carried a little away from bearer.
Q. What is the purpose of this precaution?
A. To prevent bearer from being burned by particles of molten metal being thrown off by spluttering bomb.
Q. Are tongs widely used for removal of burning bombs?
A. The shower of sparks from the burning magnesium bomb would make it dangerous and difficult to carry a bomb at such close quarters if proper protective clothing were not being employed.
Q. Can a burning incendiary bomb be dropped from a window to the ground below without causing a fire hazard?
A. Yes, if it lands on earth, on pavement or on concrete or brick walk.
Q. Any particular objection to this method of disposal?
A. Yes, the glare from the burning bomb may serve as a target to enemy bombers.
Q. For what purpose is a wetted blanket used in connection with operations on burning incendiary bombs?
A. Protection of the operator in the event that the bomb explodes; also to protect the operator when he is in close proximity of the burning bomb.
Q. What other method than the use of a wet blanket is employed to protect the operator when directing a stream or spray at a burning incendiary bomb?
A. Crouching behind a chair or table tipped to its side, or behind a box, large board or other improvised shield.
Q. Is the snuffer effective in extinguishing a burning magnesium bomb?
A. No. It requires a snuffer that is practically airtight to extinguish a burning magnesium bomb.
Other Types of Incendiary Bombs
Q. What type of incendiary bombs, other than the one kilogram magnesium bomb, have been used by the enemy?
A. Magnesium bombs of two, 51/2, ten and twenty-five kilograms weight (41/2, twelve, twenty-two and 50 1/8 pounds) ; thermit bombs, white phosphorous bombs, multiple effect bombs, oil bombs and incendiary “calling cards” (also called “incendiary leaves”).
Q. Are the larger magnesium bombs similar to the one kilogram bomb?
A. Yes, with one exception: practically all the larger ones contain an explosive, while only about one in fifty of the one-kilogram bombs are so equipped.
Q. Of what size, or weight, are thermit incendiary bombs?
A. Usually made in two sizes: fifteen kilograms (thirty-three pounds) and fifty kilograms (132 pounds).
Q. Of what does a thermit bomb consist?
A. A container filled with thermit, a mixture of aluminum and iron oxide in powdered form, and provided with ignition mechanisms. Some thermit bombs are also provided with an explosive charge.
Q. Is the thermit bomb widely used?
Q. Why not?
A. It is heavier than a magnesium bomb, burns out in but one to two minutes and upon burning generates but one-eighth the amount of heat produced by burning a like weight of magnesium.
Q. Of what does the phosphorus bomb consist?
A. A container filled with white phosphorus and provided with an explosive charge.
Q. How large are they?
A. Almost any size up to twenty kilograms in weight.
Q. Are they effective incendiary agents?
A. Only for highly inflammable materials such as grain fields, forests, dry leaves, thatched roofs, etc. Because of its low burning temperature, phosphorus is not capable of setting fire to materials which are not readily ignited, such as floors, roofs, etc.
Q. Are they used for any other purpose than noted above?
A. Yes. as an anti-personnel agency, to demoralize troops, fire fighters, and other personnel.
Q. How does a white phosphorus bomb function?
A. When the bomb. upon dropping, strikes the ground or other firm object the explosive charge is ignited by impact and the resulting explosion scatters burning phosphorus over a large area.
Q. How does such a bomb demoralize personnel within the range of the scattered phosphorus?
4. The burning phosphorus, coming in contact with exposed parts of the body, causes painful burns. Landing on clothing, the clothing may become ignited. As phosphorus, upon burning, becomes liquid, it cannot be brushed from the clothing, nor from the skin. Furthermore, it ignites spontaneously when dry and in contact with the air, so that, even if extinguished by water, the fire will recur upon the phosphorus drying.
Q. What is a “multiple effect” bomb?
A. A bomb which contains a number of incendiary units of magnesium and phosphorus which are expelled from the bomb and scattered over a relatively wide area when the bomb explodes.
Q. Where are they likely to be used?
A. Against certain kinds of targets, such as large factory buildings, storage of military supplies and other military establishments.
Q. What is an oil bomb?
A. A bomb, five to six feet in length and eighteen inches in diameter, and containing from forty-six to fifty gallons of heavy oil. It weighs from 350 to 400 pounds. It may explode either when nearing its target or by coming in contact with it, and spread its contents over a radius of about twenty-five feet. Smaller bombs, containing about sixteen gallons of oil are also used by the enemy.
Q. Are these bombs effective?
A. Yes, particularly so in connection with bombed buildings, when the debris is saturated by burning oil.
Q. Do oil bombs ever contain anything but heavy oil?
A. Yes. Sometimes they are filled with solidified gasoline, as well as other inflammable substances.
Q. What are incendiary “calling cards”?
A. Small, square (four by four inches) “sandwiches” made up of two sheets of celluloid with white phosphorus between. They are kept moistened with water until dropped on their targets. White phosphorus, when it becomes dry, ignites spontaneously, and in the “calling card,” it ignites the celluloid. These calling cards, when moist, are dropped over forests, grain fields or other inflammable targets, and when the phosphorus dries out. fires are started.
Q. What is a “Molotov Breadbasket”?
A. A hollow shell, about four feet and eighteen inches in diameter, in which are placed from 36 to 50 one-kilogram magnesium incendiary bombs. A timing device causes detonation of an explosive charge as the “breadbasket” nears its target, and the bombs are blown in all directions. By its use a number of fires can be started within a small area.
Q. What procedure is followed in extinguishing fire involving the larger sizes of magnesium bombs?
A. Precisely the same procedure as employed with the one kilogram bomb, except that the small first aid fire lighting appliances used with the one kilogram bomb must be supplanted by equipment giving greater water discharge. Furthermore, large incendiary bombs will likely require the services of skilled fire fighters.
Q. Can burning thermit bombs be extinguished by any practical means?
A. No. Thermit supplies itself with all the oxygen needed for combustion, and it will continue to burn even under water.
Q. What, then, is the procedure in operating on fires involving thermit bombs?
A. Keep the bomb and area immediately surrounding it sprayed with water. The water will cool the molten iron produced by the burning of the bomb and prevent it from spreading the fire. At the same time the spray will prevent extension of any fire which may be caused by the flare from the bomb. The bomb will burn itself out in from one to two minutes. Should it burn through a floor, it must be followed with water spray or stream.
Q. Is it difficult to extinguish the fire involving white phosphorus?
A. No, such fire is easily extinguished.
Q. How is this accomplished?
A. By application of water or sand, the former being a far more effective agent for this purpose. After extinguishing the fire, the phosphorus must be kept wetted, otherwise it will reignite spontaneously. A solution of copper sulfate in water, on the other hand, not only extinguishes the phosphorus fire quickly but it usually prevents spontaneous reignition of the phosphorus. Note: Avoid personal contact with white phosphorus, as it causes painful burns.
Q. How are fires involving multiple effect bombs extinguished?
A. The burning magnesium pieces are handled in precisely the same manner as one-kilogram magnesium bombs; the phosphorus pieces, as described above. Removal of the unburned phosphorus pieces, after fire has been extinguished, and the pieces are still wet, to a safe place is advisable.
Q. What is the recommended procedure for extinguishing burning oil from oil bombs?
A. The vapor nozzle (fog nozzle) is highly effective for this purpose as is also sand. Foam cannot be used effectively on fires involving oil soaked debris, but is effective if oil surface can be covered with it. Carbon dioxide and dry powder extinguishers can be used if burning area is not great.
Q. How should burning “calling cards” be handled?
A. Extinguish fire with water and then collect and burn “calling cards” in a safe place or keep under water. Treatment with copper sulfate solution will prevent their reignition.
Q. Are sodium and sodiumpotassium alloys good incendiary agents?
A. They do not create sufficiently high temperatures, when burning, to ignite many combustible materials.
Q. Do they ignite spontaneously?
A. Yes, in the presence of moisture, and therefore must be kept absolutely dry or be stored submerged in oil.
Q. How are fires involving these materials extinguished?
A. By covering with dry sand.
Q. Should water streams or spray be used upon them?
A. Application of water would cause violent reaction and would increase the intensity of the fire greatly.
Some Miscellaneous Questions and Answers on Incendiary Bombs
Q. How can a surface be protected to prevent penetration by a one kilogram bomb?
A. By covering it with a steel plate 1/4-inch thick, a layer of sandbags closely laid, or by a 5-inch layer of reinforced concrete.
Q. Assume a 1 kilogram bomb lands in an attic, what protection would be required to prevent the bomb from burning through to the floor below?
A. A layer of sand or earth 2 inches thick, a layer of ashes 3 inches thick or 1-inch thickness of plaster or asbestos board would probably prove effective.
Q. Does a 1 kilogram bomb make a noise when falling?
A. Yes, a wailing, whistling sound.
Q. What kind of smoke is produced by the oil bomb?
A. A dense, black, pungent smoke that makes close fire fighting operations difficult.
Q. Does the phosphorus bomb produce smoke when burning?
A. Yes, a dense, white, acrid smoke.
Q. How is fire spread by burning magnesium of an incendiary bomb?
A. By direct contact of burning magnesium with combustible materials, by particles of molten magnesium scattered by the burning bomb, by the flow of molten magnesium through cracks or other openings, or by radiated heat from the burning bomb.
Ignition of materials by direct contact with the burning bomb represents the major manner of fire spread.