in today's guerrilla warfare,

especially as it's practiced in the orient, one of the most challenging, dangerous problems which confront combat forces is the enemies use of earthen tunnels. tunnels and caves were used. the japanese in world war two and by the koreans during the conflict which followed. once the line of battle had moved them and the area in which they existed was secured by our troops. these subterranean fortifications were permanently neutralized as a part of the area consolidation. today, however, a different type warfare is being waged. rarely are areas held long enough to be thoroughly cleaned out. instead, the major actions of our combat troops consist of and destroy operations intensive drives through enemy with the

primary objective of finding and destroying his forces and then moving on. seldom is the occupation of terrain for extended periods objective in itself and in these situations the enemy's use of earthen tunnels becomes serious. he can hide in them until our troops pass, then emerge and attack from the rear in them. he can start for future operations in area if the enemy leaves tunnels deserted during a sweep operation and he will find shelter and operation or facilities. and then when he returns and if they are intact, he can resume his guerrilla activities almost as though no interruption had taken place. thus, it is obvious that to effectively strike the enemy and destroy his ability to wage war in guerilla situations, his

tunnel shelters must be demolished or denied him as they are encountered. this is a relatively new but important military concept for tunnel users included in the doctrine of various armed forces, particularly in the orient in the future. this doctrine may well be applied not only to guerrilla warfare, but to any type of conflict anywhere in the world. therefore, understanding of earth and tunnels and the means of destroying or neutralizing is essential to today's soldier. earthen tunnels may be dug or utilized in military operations wherever the tactical situation warrants, although they are practical only where large civilian forces are available for their construction construction. earthen consist of two general types. first, there are those called

expedient. they are relatively simple construction and varying in length from approximately 20 to several hundred feet. this type includes ambush safe, hide, riverbank or escape tunnels. such tunnels are not intended to provide permanent protection or shelter for their occupants. the second type is made up of several levels of tunnels called a complex, which a series of rooms interconnected, many smaller tunnels. a complex may extend to 30 feet in depth below the earth's surface and extend over a large areas they have carefully entrances to facilitate evasion and escape. in complexes such as these personnel may be hidden, housed, trained, hospitalized. a headquarters be set up and maintained and supplies stored. many of these complexes date back to world war two and since have been enlarged and

reinforced to provide maximum protection against air and artillery strikes. such huge complexes are generally found away from populated centers. they are the most difficult to but can be destroyed if. time, supplies, equipment, personnel are available. when a tunnel entrance is discovered. area around it must be examined. booby traps or mines. these are generally used by the enemy for protection or warning and until this check has been completed, the should not be entered. before entering a tunnel. recon must have the equipment they need to do the job. a powerful flashlight in good condition and with fresh batteries and a probe such as a bayonet is must so as a protective mask and a hand

weapon. with the entrance area. the next step is to perform a thorough reconnaissance of the tunnel to determine how recently it has been used and if enemy personnel present this reconnaissance is essential a powerful should be avoided for fired in a tunnel. their intense sound can cause deafness lasting long as 30 minutes and a tunnel and crushing team need all their in full working order at all times. when a tunnel entrance shaft goes vertically into the ground as here the first man to enter it should be slowly lowered into the shaft head first to permit him to thoroughly check the entrance walls and floor for booby traps. all mines as moves into the tunnel.

when the is over eight feet deep. the point man should be secured with a rope so that he can be pulled to safety in case of emergency. as the point man arrives in the tunnel, he carefully checks to

be certain that no enemy is awaiting him. near the entrance. if the area is clear, he works his way into the tunnel and his backup men as, they enter the tunnel. both men must be alert for any odor which suggests presence of chemical agents and if such odors are detected, protective masks must be done. continuing follow. when both men are in the tunnel, they begin their reconnaissance cautiously and carefully carefully initial reconnaissance limited to the first ten feet of a tunnel. if it continues beyond ten feet, the recon team should return to the entrance to pick six grenades and communication equipment. then they resume the reconnaissance of the entire complex in this demonstration. this is permitted. during tunnel reconnaissance.

always assume that the enemy is somewhere in. the tunnel he probably is. and always assume that the tunnel booby trapped, particularly in more elaborate complexes where, the enemy has had ample time to install traps. carefully, examine all surfaces of the tunnel floor, walls and ceiling for booby traps or mines as. well, as for false walls or a hidden passageways, never undertake a tunnel reconnaissance with less than two men on the recon team and state within the tunnel complex that times.

observe extreme caution to protect yourself against the who may lie in wait just beyond. during a tunnel. each man has a definite to do the point man concerned with booby traps and mines as well as the possibility of enemy contact. the backup man is alert for information of intelligence value. he also notes details of the tunnel construction and layout and estimates the depth of soil which lies over the tunnel throughout its entire length. this soil is called overburden. when tunnel has been thoroughly explored and extent, size, depth and contents have been determined. this is carefully and completely

noted then the precise location of the tunnel established this information must then be reported through channels to tactical commander. on the basis of factors which are inherent in the overall combat situation. the commander will decide whether the tunnels should be destroyed or otherwise denied to the enemy bypassed. the of desire, demolition or denial may be left up to the unit commander commander. the factors which will determine the type of tunnel denial to be undertaken combat operations will relate the tactical situation at the time time. first, how much time is available? destruction, how much time the primary mission allow for such work? second, how much time is

necessary for total or partial destruction. these must be weighed against each other. third, what equipment and personnel required for the different types of denial in relation to the tunnel in question? are such personnel and equipment available? finally, how important is the tunnel complex to the enemy. how valuable will it be on his return to the area? these are the things which must be considered in determining the type of tunnel destruction or denial appropriate to an individual's situation situation. the methods of tunnel denial, which be employed in combat situations, be divided into three general category. first, immediate denial which can be completed in minutes with equipment normally at hand. second, partial destruction, which also can be accomplished within relatively brief periods of time with available equipment

and. finally, total destruction, which requires trained troops and equipment normally carried into combat areas. the purpose of immediate denial tunnel action is to flush the enemy out of his hiding place and deny him its use for a decisive period of time. the results obtained are immediate, although a relatively brief duration. to drive the enemy from. the tunnel cease is used in solution or powder form. when cs powder is used, the material is liberally sprinkled into the entrance. the tunnel is then as tightly as possible, forcing the cs fumes to spread back into the underground passageways and drive the enemy out through other exits, since normally they have no protective masks available.

the 106 chemical dispenser can be carried by one man and may be used to blow chemicals into a tunnel. after checking the area for enemy personnel and booby a poncho or other suitable cover is placed over the entrance. the discharge from the dispenser is inserted through. the cover ensuring that a tight seal maintained around the hose. the outer edge of the poncho is sealed to prevent the chemical from escaping.

after all openings of. the engine has started. the fan then forces chemical throughout the tunnel. may also be introduced into by using cs grenades. as all such denial efforts the tunnel should be tightly covered to prevent the of the costumes and force back into the passageways. partial destruction involves damaging the tunnel so that it will be immediately useless to the enemy and reusable only after considerable repair, generally concussion or grenades are tossed into a tunnel or shaft entrance to collapse it. the destructive effect these

grenades will depend on the amount of overburden at the point of explosion. if the overburden is relatively light, the grenades may completely collapse. the entrance or shaft and seal off the entryway. even if complete collapse is not obtained, grenades will usually dislodge enough earth to effectively block the entrance. all entrances must be treated in this way to completely neutralize the tunnel complex. military, such as dynamite tnt or c-4, also be used in partial tunnel destruction. c-4, normally available under combat conditions in m 37. demolition charge assembly kits.

using, the blasting cap creepers contained in the demolition kit. prepare two of the blocks to receive the demolition. priming assembly boosters. two of these assemblies are contained in kit. they consist of five foot lengths of detonate cord with a priming adapter and attached to each end. place the boosters into two of the eight blocks. to complete the firing chain. attach an electric cap with firing or a non-electric cap with a length of time views to the demolition kit. we will use a non-electric assembly cut piece of time views of sufficient length, allow personnel to move back to a safe area.

placed in non-electric cap onto a time fuze. crimping using blasting cap crimp. attach the cap to the five foot length of detonating cord. finally attach the fuze lighter to the time. fuze.

when explosive assembly has been completed. fire intensely into the tunnel entrance to drive back any enemy who may be waiting inside. place the charge as deeply in the entrance as possible. then ignite the fuze and quickly withdraw a sheltered position a safe distance from entrance. while awaiting results. the entrance covered for enemy. these are the primary ways in which partial tunnel destruction is accomplished. in addition, unit commanders call in artillery or high angle weapons to demolish tunnel entrances entrances. the total destruction of a

tunnel, a job which should be handled only by specially trained troops using equipment not normally carried in forward areas during combat operations. thus, it obviously requires more time and is necessary for the partial destruction just demonstrated. once total destruction has been the first step is to have another thorough reconnaissance of the complex made by the specially trained personnel. assigned to the demolition. these men will make certain the tunnels are clear that no personnel or booby traps have been overlooked in the earlier exploration exploration.

they will precisely map the complex and carefully estimate the overburden throughout the entire system, making special allowances in their where multi-level tunnels involved. based on the findings of this reconnaissance, the amount of explosive be calculated and charge placement can be determined. calculation is based on rule of thumb, which is developed through extensive experimentation and experience within the area of operation. it requires consideration of two factors the amount of overburden an and tunnel length. the rule of thumb requires that four overburden up to ten feet use two pounds of explosive per foot of tunnel length.

increase the amount of explosive two pounds for each additional ten feet of overburden. the charges should be ground placed at turns or corners of the tunnel as well as at stronger points a type explosives should be used which can be prime with detonating cord. all tunnel entrances which can be discovered should be blocked with. sandbags and the shaft should be filled with well tamped dirt. this is particularly important for the more of the explosive forces confined a tunnel, the more destructive and effective it will be. in tunnel destruction, explosion

should be primed with death cord and then electric or non-electric used to initiate the action. however, electric means best because it gives you full control of the firing at all times. in certain situations. bangalore torpedoes shaped charges, cratering charges, or similar special charges may be used in total tunnel destruction. in continuing search for more effective of destroying large enemy tunnels and complexes, the army has developed this extreme to 42 liquid explosive of demolition kit for use with a powerful liquid explosive nitro methane. each kit contains the equipment to destroy a tunnel 500 feet long with an overburden of ten

feet. the can be combined to destroy larger systems having up to 30 feet of overburden. each kit includes a portable gasoline engine driven and compressor 255 gallon drums of liquid nitro methane, enough hoses to connect to the compressor, and 55 gallon drums. a. pressure relief valve designed to vent off internal line pressure, which 15 psi a valve flow control regulates flow of explosive and the monitor that indicates when drums are empty. the monitor box is connected to a sensor attached to the hose inside the drum by using 500 feet of cable. the kit also contains an arrest that provides a safety device to

prevent propagation of the detonation back to the drums and pumping equipment. tools and accessories for assembly and. finally, a drag pack containing 500 feet of lightweight lay, flat plastic tubing after the hose generator are connected to the drums. this plastic tubing is paid out, must be tied off with a figure. eight not overhand not will not hold the wire for monitor and firing wire are paid out. the monitor is connected to monitor wire. at the tunnel entrance explosive placed around tubing and primed with two blasting caps caps.

blasting. cap wire is attached to the firing wire. the compressor is started started. the safety valve is closed to start pumping the nitro methane into plastic tubing. be sure that nitro methane is flowing through the flow sensor module into plastic tubing, then move back the firing point.

at, the firing site, the firing wires are attached to the blasting machine. the monitor is until one of the lights goes out, then the charge is fired. these then are the general principles of neutralizing or destroying enemy earthen tunnels in combat. such installation should always be treated with respect and should be entered only with the utmost and the proper equipment. earthen tunnels discovered in combat situations should be thoroughly explored to determine their size, extent and significance. then the findings of the recon, together with the tunnels precise location must be reported through through the

overall tactical. he will determine direct the appropriate disposition of the installation. for immediate denial. see us in various forms, maybe by combat personnel. for this to be effective, all to the tunnel must be tightly contained to keep the agent from escaping. combat personnel accomplish partial destruction of tunnels by collapsing entrances with concussion fragmentation grenades as well as available conventional military explosives. combat troops can perform denial or partial destruction as a part of their normal. total destruction of a tunnel requires trained personnel with specialized equipment. whichever type of tunnel destruction is dictated by the tactical, it should be performed

carefully and completely, only in this way can the enemy's vital tunnels and complexes be denied him.