t¡£*r2 rlVlj"¿0 DEPARTMENT OF THE ARMY FIELD MANUAL EXPLOSIVES AND DEMOLITIONS HEADQUARTERS, DEPARTMENT OF THE ARMY TAG^Mfcateg©« Library OCTOBER 1963 Bm 1A618, Pentagon Washmgrton, D.C. 20íífO *FM 5-25 FIELD MANUAL! HEADQUARTERS, DEPARTMENT OF THE ARMY No. 5-25 WASHINGTON, D.C., 29 October 1963 EXPLOSIVES AND DEMOLITIONS Paragrftphs Page CHAPTER 1. EXPLOSIVES AND SPECIAL CHARGES Section I. Introduction 1-3 2 II. Explosives 4-18 2 III. Special charges 19-27 8 CHAPTER 2. FIRING SYSTEMS AND EQUIPMENT Section I. Nonelectric firing system 28-36 14 II. Electric firing system 37-47 34 III. Detonating cord firing system _- 48-56 47 IV. Dual firing systems -. 57-60 58 V. Demolition sets 61-63 60 CHAPTER 3. CALCULATION AND PLACEMENT OF CHARGES Section I. Requirements and procedures 64-68 63 II. Timber-cutting charges 69-73 67 III. Steel-cutting charges 74-78 70 IV. Pressure charges , 79-83 75 V. Breaching charges 84-88 77 VI. Cratering and ditching charges 89-95 81 VII. Land clearing and quarrying charges -- - 96-100 85 CHAPTER 4. DEMOLITION ORDERS AND PROJECTS Section I. Target reconnaissance and demolition orders 101-103 88 II. Techniques common to most demolitions 104-107 102 III. Bridge demolitions 108-122 103 IV. Disruption of transportation lines — - 123-128 117 V. Disruption of communications systems 129-130 122 VI. Destruction of buildings and installations 131-134 122 VII. Destruction of equipment and supplies ■ 135-139 123 CHAPTER 5. SAFE HANDLING, TRANSPORTATION, AND STORAGE OF EXPLOSIVES Section I. General safety precautions. - 140-142 125 II. Handling of specific explosives 143-149 126 III. Transportation, storage, and disposal 150-154 128 APPENDIX I. REFERENCES... 130 II. METRIC CALCULATIONS. 131 III. USE OF LAND MINES, AERIAL BOMBS, AND SHELLS AS DEMOLITION CHARGES 134 IV. SUMMARY OF EXPLOSIVE CALCULATION FORMULAS 136 V. POWER REQUIREMENTS FOR MULTIPLE FIRING CIRCUITS 138 VI. ADVANCED AND EXPEDIENT DEMOLITION TECHNIQUES 143 VII. USE OF EXPLOSIVES IN THE ARCTIC 152 INDEX 156 'This manual ivpersedes FM 5-25, 14 May 1959, including C I, 3 August 1960, and C 2, 27 December 1961. TAGO 10111-A—October CHAPTER 1 EXPLOSIVES AND SPECIAL CHARGES Seefîiera I. ÎMTRODUCTION 1. Purpose and Scope 2. Comments a. This manual is a guide in the use of explosives Users of this manual are encouraged to submit for the creation and demolition of military obstacles eomments or recommendations for changes for and in certain construction projects. The material improvement. Comments should be referenced to includes information on— the specific page, paragraph, and line of text, and (1) Types, characteristics, and uses of ex- reasons for each comment given to insure proper plosives. understanding and evaluation. Comments should be forwarded direct to the Commandant, U.S. (2) Preparation, placement, and firing of Army Engineer School, Fort Belvoir, Va. charges. (3) Calculation formulas. (4) Deliberate and hasty demolition methods Military demolitions are the destruction by fire, appropriate for use in the forward zone. water, explosive, and mechanical or other means, of (5) Handling, transportation, and storage of areas, structures, facilities, or materials to ac- explosives. complish the military objective. They have offen- (6) Safety precautions. sive and defensive uses, for example, the removal of enemy barriers to facilitate the advance, and the b. The contents of this manual are applicable to construction of friendly barriers to delay or restrict nuclear and nonnuclear warfare. enemy movement. m 4. ®@fQK)55iic2)[ñis almost instantaneously, producing a shattering a. Explosives. Explosives are substances that effect upon the target. Detonation rates range through chemical reaction violently change and from 3,281 feet to 27,889 feet per second. High release pressure and heat equally in all directions. explosives are used where this shattering effect is Explosives are classified as low or high according required—in certain demolition charges and in to the speed (feet per second) with which this charges in mines, shells, and bombs. change takes place. b. Low Explosive. Low explosives deflagrate or ü. ClnKäD'tsigta'bflks ©'S ¡MWiMvy IxplosDwgs change from a solid to a gaseous state relatively Explosives used in military operations possess slowly over a sustained period. This quality makes the low explosive ideal for pushing or shoving a certain properties or characteristics essential to target. Examples are the smokeless and black their function. In the past, many explosives have powders that change from the solid to the gaseous been studied for possible military use; but the state at relatively slow rates. requirements are such that less than a score have c. High Explosive. The change in this type of proved satisfactory for standardization. The es- explosive to a gaseous state—detonation—occurs sential characteristics of military explosives are— TAGO lOlll-A a. Relative insensitivity to shock or friction; and 6. Selection of Explosives not liable to detonation by small arms fire. The explosives satisfactory for military purpose b. Proper detonating velocity. are generally selected on the basis of velocity of c. High power per unit of weight. detonation. For example, an explosive having a high detonating velocity is generally used for d. High density (weight per unit of volume). cutting and breaching; that of a lower velocity, for e. Sufficient stability to retain usefulness for a cratering, ditching, and quarrying. The types reasonable time in storage in any climate. commonly used are described below. /. Positive detonation by easily prepared primers. 7. TNT (Trinitrotoluene) g. Suitability for underwater use. Trinitrotoluene (fig. 1), commonly known as TNT h. Convenient size and shape to facilitate pack- is one of the least sensitive of military high ex- aging and logistics and handling by troops. plosives. It is reasonably stable in any climate, i. Capability over a wide range of temperatures. does not readily absorb water, and is quite stable 1/4 LB BLOCK 1/2 LB BLOCK OD COVER O.D. COVER I LB BLOCK TNT OD COVER THREADED CAP WELL Figure 1. TNT blocks. TAGO 10111-A TETRYL BOOSTER TETRYTOL TETRYL BOOSTER DETONATING CORD Figure S. Ml chain and MS demolition blocks. in closed storage. The detonation rate is 21,000 these threads. Fifty 1-pound blocks are feet per second. packed in a wooden box. o. Packaging. TNT is packaged in J^-pound, b. TNT is used primarily in cutting and breach- ^-pound, and 1-pound blocks. ing operations. (1) The J4-pound blocks are in an olive drab c. Detonation. Military electric or nonelectric cardboard container with metal ends. One blasting caps and PETN detonating cord, or any of end has a threaded cap well. Two the firing devices having a military cap attached hundred blocks are packed in a wooden may be used to detonate TNT. box. (2) The J^-pound blocks are in a yellow or 8. Tetrytol (Ml Chain Demolition Block) olive drab cardboard container with metal Demolition block Ml has all the desirable charac- ends. The yellow container has an un- teristics of TNT and is slightly more powerful, threaded cap well and the olive drab having a detonation rate of 23,000 feet per second. container, a threaded cap well. One It is thus more effective as a cutting or breaching hundred blocks are packed in a wooden charge. It is only slightly soluble in water and is box. brittle, breaking very easily when dropped (fig. 2). (3) The 1-pound blocks are merely two H- a. Packaging. Each block is 11 inches lang by 2 pound blocks in an olive drab cardboard inches square and weighs 2% pounds. A tetryl container with metal ends. One end has a pellet is cast into the block near each end. Eight threaded cap well. Priming adapters and blocks, spaced 8 inches apart, are cast lengthwise the standard base of firing devices fit onto a single line of detonating cord, 2 feet of which TAUO lOlll-A is left free at each end of the chain. Each block is 9. Tetrytol (M2 Demolition Block) inclosed in an olive drab asphalt-impregnated paper The M2 demolition block is similar to the Ml wrapper. One chain (8 blocks) is packed in an olive chain block except that it has a threaded cap well in , rfrab cloth haversack with a ■o^]sryiti& strap attached. each end but has no core of detonating cord. The The complete"Bäg"nieasures 4 oy 8 by 11 inches and I M2 demolition block measures 11 by 2 by 2 inches. weights about 22 pounds. It contains 20 pounds of I A booster tetryl pellet, cast into the"b'Kackî surrounds explosive. Two chains are packed in a wooden box. : each cap well. b. Use. The Ml chain demolition block may be ; a. Packaging. Eight blocks, 23^ pounds each, used in forward combat areas as an alternate to are packed in a haversack; and two haversacks, in a TNT. The complete chain, or any part of the chain, wooden box. may be laid out in a line, wrapped around a target, b. Use. The M2 demolition block is used in the or used in the haversack as it is packed. The entire same manner as the Ml block for cutting and chain will detonate, even though the blocks may not breaching. Chains may be made by connecting be in contact with each other. If less than eight blocks with detonating cord. blocks are needed, the required number is cut from 10. Composition C3 (M3 or M5 Demolition the chain. Each block must have 8 inches of Block) detonating cord attached. Composition C3 (fig. 3) is a yellow, odorous, c. Detonation. Tetrytol is detonated by the mili- plastic explosive more powerful than TNT. In tary electric or nonelectric blasting cap.