Archive – ATP/FM 3-21.8 (2016) – Appendix H: Obstacle Reduction and Employment

This is an excerpt from an old version of the manual ATP/FM 3-21.8 Infantry and Rifle Platoon Squad released in 2016. It has since been superseded by a newer version released in 2024.

SECTION I – OBSTACLE TYPES AND CATEGORIES

H-1. An obstacle is an obstruction designed or employed by friendly or enemy forces to disrupt, fix, turn, or block the movement of the opposing force. Obstacles can impose additional losses in personnel, time, and equipment. It is e vital Infantry leaders and Soldiers are knowledgeable in the various types of obstacles; not only to employ them, but to reduce them when employed by enemy forces.

H-2. U.S. forces’ employment of certain obstacles, mines, and anti-handling devices (AHDs) are governed by the Law of Land Warfare and applicable international laws. Rules governing their employment also are listed in the appropriate sections in this appendix.

H-3. There are four general types of obstacles. Each type is determined by its distinct battlefield purpose and overall concept of the operation:

• Protective obstacles are employed to protect Soldiers, equipment, supplies, and facilities from enemy attacks or other threats.
• Tactical obstacles directly affect the opponent’s maneuver in a way giving the defending force a positional advantage.
• Nuisance obstacles impose caution on opposing forces. They disrupt, delay, and sometimes weaken or destroy follow-on echelons.
• Phony obstacles deceive the attacking force concerning the exact location of real obstacles. They cause the attacker to question his decision to breach and may cause him to expend his reduction assets wastefully.
  • Phony minefields are used to degrade enemy mobility and preserve-friendly mobility.
  • Intended to simulate live minefields and deceive the enemy, they are used when lack of time, personnel, or materiel prevents use of actual mines.
  • They also may be used as gaps in live minefields.
  • A phony minefield must look like a live minefield, so Soldiers must bury metallic objects or make the ground look as though objects are buried.

H-4. Obstacles are employed by both friendly and enemy forces. The main categories of obstacles are:

• Existing obstacles.
• Reinforcing obstacles.

EXISTING OBSTACLES

H-5. Existing obstacles are those natural or cultural restrictions to movement that are part of the terrain. Existing obstacles can be reinforced into more obstacles. They normally are in defilade from enemy observation (located where observation and fires can prevent the opposing force from breaching them), and are difficult to bypass. Existing obstacles include two types, natural and cultural. The following are examples: (Refer to ATP 3-34.22 for more information.)

• Natural.
  • Swamps.
  • Dense forests.
  • Deep, steep-sloped ravines.
  • Rivers.
  • Streams.
  • Hills or mountains with excessive slopes.
• Cultural.
  • Urban areas.
  • Quarries.
  • Railroad beds.
  • Built-up or elevated roads.
  • Potential storage sites.

REINFORCING OBSTACLES

H-6. Reinforcing obstacles are used by both friendly and enemy forces to tie together, anchor, strengthen, and extend existing obstacles. Careful evaluation of the terrain to determine its existing obstructing or canalizing effect is required to achieve maximum use of reinforcing obstacles. Installation time and manpower usually are the two most important factors. The reinforcing obstacles are—

• Land mines.
• Constructed obstacles.
• Demolition obstacles.
• Improvised obstacles.

LANDMINES

H-7. Land mine is a munition on or near the ground or other surface area that is designed to be exploded by the presence, proximity, or contact of a person or vehicle. Land mines can be employed in quantities within a specific area to form a minefield, or they can be used individually to reinforce nonexplosive obstacles. Land mines fall into the following two general categories: persistent and nonpersistent. Persistent means they are not capable of self-destructing or self-deactivating. Nonpersistent means they are capable of self-destructing or self-deactivating. (See figure H-1.) (Refer to ATP 3-34.20 for more information.)

Figure H-1. Methods of activating mines

CONSTRUCTED OBSTACLES

H-8. Units create constructed obstacles with manpower or equipment without the use of explosives. Examples of constructed obstacles include:

• Ditches. Ditches across roads and trails are obstacles. Large ditches in open areas require engineer equipment.
• Log hurdles. Log hurdles act as “speed bumps” on roads. They are installed easily and are most effective when used in conjunction with other obstacles.
• Log cribs. A log crib is constructed of logs, dirt, and rocks. The logs are used to make rectangular or triangular cribs filled with dirt and rock.
• These are used to block narrow roads and defiles. Unless substantially built, log cribs will not stop tanks.
• Log posts. Log posts embedded in the road and employed in-depth can stop tracked vehicles. If they are not high enough to be pushed out of the way, posts can cause a tracked vehicle to throw a track if it tries to climb over. If employed with wire and mines, they also can slow enemy Infantry.
• Wire entanglements. Wire entanglements impede the movement of dismounted enemy Infantry, and in some cases, tracked and wheeled vehicles.
  • Triple standard concertina is a common wire obstacle. However, there are other types, such as double apron, tanglefoot, and general-purpose barbed-tape obstacles.
  • Figures H-2a through H-2c (pages H-5 through H-6) illustrate examples of wire and log obstacles. The materials used in constructing wire entanglements are relatively lightweight (compared to other obstacles) and inexpensive, considering the protection they afford.

Figure H-2a. Constructed wire and log obstacles

Figure H-2b. Constructed wire and log obstacles

Figure H-2c. Constructed wire and log obstacles

DEMOLITION OBSTACLES

H-9. Units create demolition obstacles by detonating explosives. ATP 3-34.20 covers demolitions in detail. There are many uses for demolitions, but some examples are road craters and abatis.

H-10. Road craters are obstacles on roads or trails if the areas on the flanks of the crater are tied into steep slopes or mined areas. Road craters can compel the opposing force to use earthmoving equipment, blade tanks, or mechanical bridging assets.

H-11. Abatis are only effective if large enough trees, telephone poles, or other similar objects are available to stop the opposing force. An abatis is an obstacle created by cutting down trees so their tops are crisscrossed and pointing toward the expected enemy direction. It is most effective for stopping vehicles in a forest or narrow movement routes. This obstacle may be reinforced with claymore or non- persistent mines.

IMPROVISED OBSTACLES

H-12. Improvised obstacles are designed by Soldiers and leaders with imagination and ingenuity when using available materiel and other resources. An example of obstacles in urban terrain is shown in figure H-3. Improvised obstacles include the following:

• Rubble. Rubble from selected masonry structures and buildings in a built-up area will limit movement through an area and provide fortified fighting positions.
• Battle damage. Damaged vehicle hulks or other debris are used as roadblocks.
• Flooding. Flooded areas are created by opening floodgates or breaching levees.

Figure H-3. Urban obstacles

SECTION II – OBSTACLE REDUCTION

H-13. Mobility operations involve obstacle reduction by maneuver and engineer units to reduce or negate the effects of existing or reinforcing obstacles. Infantry units must be proficient in the reduction of obstacles to enable the movement of combat power through obstacles while continuing to the objective.

BREACHING FUNDAMENTALS

H-14. Suppress, obscure, secure, reduce, and assault (SOSRA) are the breaching fundamentals being applied to ensure success when breaching against a defending enemy. These obstacle reduction fundamentals always will apply, but they may vary based on METT-TC.

SUPPRESS

H-15. Suppression is a tactical task used to employ direct or indirect fires or an electronic attack on enemy personnel, weapons, or equipment to prevent or degrade enemy fires and observation of friendly forces. The purpose of suppression during breaching operations is to protect forces reducing and maneuvering through an obstacle. Suppression is a missioncritical task performed during breaching operation. Suppression generally triggers the rest of the actions at the obstacle. Fire control measures ensure all fires are synchronized with other actions at the obstacle. Although suppressing the enemy overwatching the obstacle is the mission of the support force, the breach force should provide additional suppression against an enemy the supporting force cannot suppress.

OBSCURE

H-16. Obscuration must be employed to protect forces conducting obstacle reduction and passage of assault forces. Obscuration hampers enemy observation and target acquisition by concealing friendly activities and movement. Obscuration smoke deployed on or near the enemy’s position minimizes its vision. Screening obscurants employed between the reduction area and the enemy conceals movement and reduction activities. It also degrades enemy ground and aerial observations. Obscuration must be planned carefully to provide maximum degradation of enemy observation and fires, but it must not degrade friendly fires and control significantly.

SECURE

H-17. Friendly forces secure reduction areas to prevent the enemy from interfering with obstacle reduction and passage of the assault force through lanes created during the reduction. Security must be effective against outposts and fighting positions near the obstacle and against overwatching units as necessary. The far side of the obstacle must be secured by fires or be occupied before attempting efforts to reduce the obstacle. The attacking unit’s higher headquarters is responsible for isolating the breach area by fixing adjacent units, attacking enemy reserves in-depth, and providing counterfire support.

H-18. Identifying the extent of the enemy’s defenses is critical before selecting the appropriate technique to secure the point of breach. If the enemy controls the point of breach and cannot be suppressed adequately, the force must secure the point of breach before it can reduce the obstacle.

H-19. The breach force must be resourced with enough maneuver assets to provide local security against the forces supporting force cannot engage sufficiently. Elements within the breach force securing the reduction area also may be used to suppress the enemy once reduction is complete. The breach force also may need to assault to the far side of the breach and provide local security so the assault element can seize its initial objective.

REDUCE

H-20. Reduction is the creation of lanes through or over an obstacle to allow an attacking force to pass. The number and width of lanes created varies with the enemy situation, the assault force’s size, composition, and scheme of maneuver. The lanes must allow the assault force to rapidly pass through the obstacle. The breach force will reduce proof (if required), mark, and report lane locations and lane-marking method to higher command headquarters. Follow-on units will reduce or clear the obstacle when required. Reduction cannot be accomplished until suppression and obscuration are in place, the obstacle has been identified, and point of breach is secure.

ASSAULT

H-21. A breaching operation is not complete until:

• Friendly forces have assaulted to destroy the enemy on the far side of the obstacle as the enemy is capable of placing or observing direct and indirect fires on the reduction area.
• Battle handover with follow-on forces has occurred, unless no battle handover is planned.

BREACHING ORGANIZATION

H-22. A commander or platoon leader organizes friendly forces to accomplish breaching fundamentals quickly and effectively. This requires him to organize support, breach, and assault forces with the necessary assets to accomplish their roles. For tactical obstacle breaches, platoons and squads normally are assigned as either one or part of the following forces.

SUPPORT FORCE

H-23. The support force’s primary responsibility is to eliminate the enemy’s ability to place direct or indirect fire on friendly force and interfere with a breaching operation. It must—

• Isolate the reduction area with fires and establish a support-by-fire position to destroy, fix, or suppress the enemy. Depending on METT-TC, this may be the weapons squad or the entire platoon.
• Mass, control direct and indirect fires to suppress the enemy and to neutralize weapons able to bring fires on the breach force.
• Control obscuring smoke to prevent enemy-observed direct and indirect fires.

BREACH FORCE

H-24. The breach force assists in the passage of the assault force by detecting, creating, proofing (if necessary), marking and reporting lanes. The breach force is a combined-arms force. It may include engineers, reduction assets, and enough maneuver forces to provide additional suppression and local security. The entire Infantry platoon or squad may be part of the breach force. The breach force may apply portions of the following breaching fundamentals as it reduces an obstacle.

Suppress

H-25. The breach force must be allocated enough maneuver forces to provide additional suppression against various threats, including:

• Enemy direct-fire systems that cannot be observed and suppressed by the support force due to the terrain or the masking of the support force’s fires by the breach force as it moves forward to reduce the obstacle.
• Counterattacking and or repositioning forces that cannot be engaged by the support force.

Obscure

H-26. The breach force employs smoke pots, vehicle mounted smoke, handheld smoke or indirect fire obscurants if necessary, for self-defense and to cover lanes while the assault force is passing.

Secure

H-27. The breach force secures itself from threat forces providing close-in protection of the obstacle. The breach force also secures the lanes through the tactical obstacles once they are created to allow safe passage of the assault force.

Reduce

H-28. The breach force performs its primary mission by reducing the obstacle. To support the development of a plan to reduce the obstacle, the composition of the obstacle system must be an information requirement. If the obstacles are formidable, Infantry platoons and squads will be augmented with engineers to conduct reduction. Without engineers and special equipment such as Bangalore torpedoes and line charges, mine fields must be probed.

ASSAULT FORCE

H-29. The breach force assaults through the point of breach to the far side of an obstacle and seizes the foothold. The assault force’s primary mission is to destroy the enemy and seize terrain on the far side of the obstacle to prevent the enemy from placing direct fires on the created lanes. The assault force may be tasked to assist the support force with suppression while the breach force reduces the obstacle.

H-30. The assault force must be sufficient in size to seize the point of penetration. Combat power is allocated to the assault force to achieve a minimum 3:1 ratio on the point of penetration. The breach and assault assets may maneuver as a single force when conducting breaching operations as an independent company team conducting an attack.

H-31. If the obstacle is defended by a small enemy force, assault and breach forces’ missions may be combined. This simplifies mission command and provides more immediate combat power for security and suppression.

H-32. Fire control measures are essential because support and breach forces may be firing on the enemy when the assault force is committed. Suppression of overwatching enemy positions must continue and other enemy forces must remain fixed by fires until the enemy has been destroyed. The assault force must assume control for direct fires on the assault objective as support and breach force fires are ceased or shifted. Table H-1 illustrates the relationship between the breaching organization and breaching fundamentals.

Table H-1. Relationship between breaching organization and breaching fundamentals

DETAILED REVERSE PLANNING

H-33. The platoon leader along with the platoon sergeant and squad leaders must develop the breaching plan using the following sequence when planning for a protective obstacle breach. The platoon leader can plan to breach wire, mine fields, trenches, and craters. (See figure H-4.) The following considerations must be made:

• Reverse planning begins with actions on the objective.
• Actions on the objective drive the size and composition of the assault force.
• The size of the assault force determines the number and location of lanes to be created.
• The ability of the enemy to interfere with the reduction of the obstacle determines the size and composition of the security element in the breach force.
• The ability of the enemy to mass fires on the point of breach determines the amount of suppression and size and composition of the support force.

Figure H-4. Reverse planning

H-34. The approved technique for conducting obstacle breaching operations is SOSRA. The section focuses specifically on platoon and squad reduction techniques of land mines, construction obstacles, urban obstacles, IEDs and expedient devices.

H-35. As part of reducing obstacles, units also must detect, report, proof, and mark.

H-36. Detection is the actual confirmation of the location of obstacles. It may be accomplished through reconnaissance. It also can be unintentional (such as a vehicle running into a mine or wire). Detection is used in conjunction with information collection, bypass reconnaissance, and breaching/clearing operations. Specific detection methods for mines and IEDs are discussed more in this section.

H-37. Intelligence concerning enemy minefields is reported by the fastest means available. A SPOTREP should be sent to higher headquarters when Infantry platoons or squads have detected a minefield or other obstacle. This should be done whether they are sent on a specific minefield or obstacle reconnaissance mission, or if they encounter one in the course of normal operations. The SPOTREP should contain as much information possible including the type, location, size of the obstacle, and results of reduction efforts.

H-38. Proofing normally is done by engineers by passing a mine roller or another mine-resistant
vehicle through the minefield to verify a lane is free of mines. If the risk of live mines remaining in the lane does not exceed the risk of loss to enemy fires while waiting, proofing may not be practical. Some mines are resistant to specific breaching techniques. For example, magnetically fused mines may be resistant to some explosive blasts. So proofing should be done when the time available, the threat, and mission allows. Proofing also involves verifying other obstacles (such as wire) are free of explosive or injurious devices.

H-39. Marking breach lanes and bypasses is critical to obstacle reduction.

REDUCE A MINEFIELD

H-40. Most types of obstacles do not cause casualties directly. Minefields do have this potential, and will cause direct casualties if not reduced. Buried mines usually are found in a highly prepared defense. When training the reduction of surface-laid and buried minefields, always assume the presence of AHDs and trip wires until proven otherwise.

MINEFIELD DETECTION

H-41. The three types of minefield detection methods the platoon or squad might employ visual, physical (probing), and electronic.

Visual Detection

H-42. Visual detection is part of all combat operations. Soldiers should constantly be alert for minefields and all types of enemy obstacles. Soldiers visually inspect the terrain for the following obstacle indicators:

• Trip wires and wires leading away from the side of the road. They may be firing wires that are partially buried.
• Signs of road repair (such as new fill or paving, road patches, ditching, and culvert work).
• Signs placed on trees, posts, or stakes. Threat forces may mark their minefields to protect their own forces.
• Dead animals or damaged vehicles.
• Disturbances in previous tire tracks or tracks stopping unexplainably.
• Odd features in the ground or patterns not present in nature. Plant growth may wilt or change color; rain may wash away some of the cover; the cover may sink or crack around the edges; or the materiel covering the mines may look like mounds of dirt.
• Civilians who may know where mines or IEDs are located in the residential area.
  • Civilians staying away from certain places or out of certain buildings are good indications of the presence of mines or IEDs.
  • Question civilians to determine the exact locations.
• Pieces of wood or other debris on a road. They may be indicative of pressure or pressure-release firing devices. These devices may be on the surface or partially buried.
• Patterns of objects being used as a sighting line. An enemy can use mines fired by command, so road shoulders and areas close to the objects should be searched.
• Berms may indicate the presence of an antitank ditch.

Physical (Probing) Detection

H-43. Physical detection (probing) is time-consuming and is used primarily for mine-clearing operations, self-extraction, and covert breaching operations. Detection of mines by visual or electronic methods should be confirmed by probing.

Electronic Detection

H-44. Electronic detection is effective for locating mines, but this method is time-consuming and exposes personnel to enemy fire. In addition, suspected mines must be confirmed by probing. As in probing, 20 to 30 minutes is the maximum amount of time an individual can use the detector.

H-45. The AN/PSS-14 uses ground penetrating radar (GPR) and metal detection sensing for the detection of AP and AT mines. (See figure H-5.) Both the metal detection and GPR are active search methods that transmit electronic signals into the ground and analyze the signals that return. The metal detection and GPR audio signal can be used separately and in combination as required by local conditions. (Refer to TC 3-34.14 for more information.)

Figure H-5. AN/PSS-14 mine detector in operation

H-46. The AN/PSS-12 mine detector (see figure H-6) is effective at finding metallic mines, but is less effective against low-metal mines. Employment and operation procedures of the AN/PSS-12 are discussed in ATP 3-34.20. The detector is handheld and identifies suspected mines by an audio signal in the headphones.

Figure H-6. AN/PSS-12 mine detector

MINEFIELD REDUCTION AND CLEARING EQUIPMENT

H-47. Minefield reduction and clearing equipment is broken down into explosive, manual, mechanical, and electronic. While chiefly an engineer task, the platoon or squad might need to reduce a minefield depending on the situation. The leader masses reduction assets to ensure they will create as many lanes as necessary to ensure the rapid passage of the assault force through the obstacle system. If necessary, the leader must carefully plan and synchronize the creation of additional lanes to reduce the potential for fratricide with assaulting troops. The distance between lanes depends on the enemy, the terrain, the need to minimize the effects of enemy artillery, the direct-fire plan of the support force, command control, and reduction-site congestion.

H-48. The breach force should be organized and equipped to use several different reduction techniques in case the primary technique fails. Additional reduction assets should be present to handle the unexpected. Normally, 50 percent more reduction assets than required for obstacle reduction are positioned with the breach force. Mechanical and electronic reduction techniques and equipment are employed by engineers and can be found in ATP 3-34.20.

Explosive Minefield Reduction

H-49. ATP 3-34.20 lists all explosive minefield reduction techniques and equipment. The different types of explosive minefield-reduction equipment the platoon or squad might use to breach obstacles are discussed below.

M1A1/M1A2 Bangalore Torpedo

H-50. The Bangalore torpedo (see figure H-7) is a manually emplaced, explosive-filled pipe designed to create a lane in wire obstacles and is also effective against simple pressure-activated AP mines. The M1A1 and M1A2 kits are issued as a demolition kit that consists of 10 1.5-meter tubes, 10 connecting sleeves, and one nose sleeve. Each tube contains four kilograms of HE and weighs six kilograms. The kit clears a 1-by 15-meter lane.

H-51. The M1A3 Bangalore torpedo demolition kit consists of eight charge assemblies, eight connecting sleeves, and two nose sleeves. The tube assemblies, or torpedoes, are steel tubes 2 1/2 feet long and 2 1/8 inches in diameter, grooved and capped at each end. The torpedoes have a 4-inch composition A3 booster (1/2 pound each) at both ends of each 2 1/2 foot section. The main explosive charge is five pounds of composition B4. The primary use of the torpedo is for clearing lanes through wire obstacles and heavy undergrowth. It will clear a 3- to 4-yard-wide path through wire obstacles.

Figure H-7. Bangalore torpedo

H-52. All torpedo sections have a threaded cap well at each end so they can be assembled in any order. The connecting sleeves are used to connect the torpedo sections together. An individual or pair of Soldiers connect the number of sections needed, and push the torpedo through the antipersonnel minefield before priming the torpedo. A detailed reconnaissance is conducted before using the Bangalore torpedo to ensure trip wires have not been used. The Bangalore torpedo generates one short impulse. It is not effective against pronged, double-impulse, or pressure-resistant antipersonnel or antitank mines.

WARNING
Do not modify the Bangalore torpedo. Cutting the Bangalore in half or performing other modification could cause the device to explode.

Antipersonnel Obstacle Breaching System

H-53. The Antipersonnel Obstacle Breaching System (APOBS) (see figure H-8, page H-18) is a man-portable device capable of quickly creating a footpath through AP mines and wire entanglements. It provides a lightweight, self-contained, two-man, portable line charge rocket-propelled over AP obstacles away from the obstacle’s edge from a standoff position

H-54. For dismounted operations, the APOBS is carried in 25-kilogram backpacks by no more than two Soldiers for a maximum of two kilometers. One backpack assembly consists of a rocket-motor launch mechanism containing a 25-meter line-charge segment and 60 attached grenades. The other backpack assembly contains a 20-meter line-charge segment and 48 attached grenades.

H-55. The total weight of the APOBS is about 54 kilograms. It is capable of creating a lane about 0.6 by 45 meters and is fired from a 25-meter standoff.

Figure H-8. Antipersonnel obstacle breaching system

Man Portable Line Charge

H-56. The man portable line charge (MPLC) is a lightweight, man-portable; rocket-launched explosive line charge system that assists in breaching through a complex mined or trip-wired environment. (See figure H-9.) The MPLC NSN No. 1375-01-593-8347, provides a precise, portable mine clearing weapon system at the small tactical unit level providing the ability to create a lane in urban and complex mined or trip-wired environments. Mobility and survivability is increased due to immediate precision fire from covered or concealed positions.

H-57. The system weighs about 35 pounds and can easily be carried, set up, and detonated by one Soldier. It is a rocket-launched explosive system designed to clear an area of other explosives. A Soldier proficient on the MPLC can set up and detonate an explosive in about one minute.

H-58. The MPLC provides small tactical units with the ability to conduct clearing operations in urban and complex, mined or trip-wired environments; in covered or concealed positions. It is designed to assist in the clearing of a narrow footpath to a target by exposing, disrupting or neutralizing IED trigger mechanisms, while minimizing collateral effects on noncombatant personnel, structures and property.

H-59. The MPLC system is self-contained in a backpack designed for carry and deployment by one Soldier. The system requires no additional special tools or equipment, however, a hammer, may be needed to secure the launch pad to the ground. Once the system is in place, a “shock tube” firing system will initiate the rocket and detonate the line charge.

H-60. MPLC offers a three-prong approach to optimal breaching effectiveness: It reduces time on target, improves information operations by reducing collateral damage during tactical operations and improves freedom of movement.

H-61. MPLC is composed of a plastic bonded explosive line charge, a small rocket motor used to deploy the line charge, an arresting strap, a launch rod, and dual shock tube housed in a SKIN-PACK detonator assembly. The shock tube is initiated by two M81 firing devices. The shock tubes are connected through an energetic transfer assembly that contains a PBXN-5 booster. All of these items are contained in a backpack.

Figure H-9. Man portable line charge

Manual Minefield Reduction

H-62. Manual procedures normally are conducted by engineers (but also can be performed by Infantry units) and are effective against all obstacles under all conditions. Manual procedures involve dismounted Soldiers using simple explosives or other equipment to create a lane through an obstacle. These procedures expose the Soldier and may be manpower and time-intensive. While mechanical and explosive reduction procedures normally are preferred, Infantry platoons or squads may have to use manual procedures for the following reasons:

• Explosive, mechanical, and electronic reduction assets are unavailable or ineffective against the type of obstacle.
• Terrain limitations.
• Stealth is required.

H-63. Different manual reduction techniques for surface-laid and buried minefields are discussed below.

Surface-Laid Minefield

H-64. First use grappling hooks from covered positions to check for trip wires in the lane. The limited range of the tossed hook requires the procedure to be repeated through the estimated depth of the obstacle. A demolition team then moves through the lane. The team places a line main down the center of the lane, ties the line from the explosive into the line main, and places blocks of explosive next to surface laid mines. After the mines are detonated, the team makes a visual check to ensure all mines were cleared before directing a proofing roller and other traffic through the lane. Demolition team members are assigned special tasks such as grappler, detonating-cord man, and demolitions man. All members should be cross-trained on all procedures. Demolitions are prepared for use before arriving at the point of breach. The platoon and squad must rehearse reduction procedures until execution is flawless, quick, and technically safe. During reduction, the platoon or squad will be exposed in the lane for five minutes or more depending on the mission, the minefield depth, and Infantry platoon’s or squad’s level of training.

Buried Minefield

H-65. Manually reducing a buried minefield is extremely difficult to perform as part of a breaching operation. If mine burrows are not easily seen, mine detectors and probes must be used to locate mines. Mines then are destroyed by hand-emplaced charges. As an alternative, mines can be removed by using a grappling hook and, if necessary, a tripod. (See figure H-10.) Using a tripod provides vertical lift on a mine, making it easier to pull the mine out of the hole.

H-66. The leader organizes Soldiers into teams with distinct, rehearsed missions including grappling, detecting, marking, probing, and emplacing demolitions and detonating cord. Platoons or squads are exposed in the obstacle for long periods.

Figure H-10. Tripod

Grappling Hook

H-67. The grappling hook is a multipurpose tool used for manual obstacle reduction. Soldiers use it to detonate mines from a standoff position by activating trip wires and AHDs. After the grapnel is used to clear trip wires in a lane, dismounted Soldiers can move through the minefield, visually locate surface laid mines, and prepare mines for demolition. In buried minefields, Soldiers grapple and enter the minefield with mine detectors and probes.

H-68. Multiple grapplers can clear a lane of trip wires quickly and thoroughly, but they must time their efforts and follow procedures simultaneously. A hit on a trip wire or a pressure fuse can destroy the grappling hook and cord, so the platoon and squad should carry extras.

H-69. There are two types of grappling hooks: hand-thrown and weapon-launched.

H-70. Hand-thrown. A 60+-meter light rope is attached to the grappling hook for hand throwing. The throwing range is usually no more than 25 meters. The excess rope is used for standoff distance when the thrower begins grappling. The thrower tosses the grappling hook and seeks cover before the grappling hook and rope touch the ground in case their impact detonates a mine. He then moves backward, reaches the end of the excess rope, takes cover, and begins grappling. Once the grappling hook is recovered, the thrower moves forward to the original position, tosses the grapnel, and repeats the procedure at least twice. He then moves to the end of the grappled area and repeats this sequence through the depth of the minefield.

H-71. Weapon-launched. A 150-meter lightweight rope is attached to a lightweight grappling hook designed to be fired from an M16 or M4-series rifle using an M855 cartridge. The grappling hook is pushed onto the rifle muzzle with the opening of the retrieval-rope bag oriented toward the minefield. The shooter is located 25 meters from the minefield’s leading edge and aims the rifle muzzle at a 30-to 40-degree angle for maximum range. Once fired, the grappling hook travels 75 to 100 meters from the firer’s position. After the weapon-launched grappling hook (WLGH) has been fired, the firer secures the rope, moves 60 meters from the minefield, moves into a prone position, and begins to grapple. The WLGH can be used only once to clear a minefield, but it can be reused up to 20 times for training because blanks are used to fire it.

Demolitions

H-72. Different types of demolitions can be used for minefield obstacle reduction. (See table H-2, page H-22.) FM 3-34.214 covers each different type of demolition available to support all Infantry missions. Demolitions are used differently against certain types of mines:

• Pressure-Fused AP Mine. Place at least a one-pound charge within 15.2 centimeters of simple pressure-fused mines. Ensure the charge is placed within 2.54 centimeters of blast-hardened mines.
• Trip-Wire/Break-Wire-Fused AP Mine. Place at least a one-pound charge within 15.2 centimeters of the mine after the mine at the end of a trip wire has been located. Soldiers can use elevated charges if necessary against the Claymore and stake-type mines.
• Influence-Fused AP Mine. Do not use demolitions.
• Command-Detonated Blast Mine. Ensure the observer is neutralized before approaching. Elevated charges can be used if necessary against Claymores.

Table H-2. Demolitions

MARKING AND CROSSING THE MINEFIELD

H-73. Lane marking allows the leader to project the platoon or squad through the obstacle quickly with combat power. It also gives Infantry platoons or squad’s confidence in the safety of the lane and helps prevent unnecessary minefield casualties.

H-74. Once a footpath has been probed and mines marked or reduced, a security team should cross the minefield to secure the far side. After the far side is secure, the rest of the unit should cross. If mines and trip wires have been identified but not reduced, the mine and line of the trip wire are marked along the ground surface, 12 inches before the trip wire. (See figure H-11.)

Figure H-11. Marking a footpath

REDUCE A CONSTRUCTED OBSTACLE

H-75. Reduction methods for enemy wire and tank ditch obstacles are as follows.

REDUCE A WIRE OBSTACLE

H-76. The enemy uses wire and concertina obstacles to separate Infantry from tanks and to slow or stop the Infantry movement. His wire obstacles are similar to ours. On patrol, reducing a wire obstacle may require stealth and is conducted using wire cutters or by crawling under or crossing over the wire. It may not require stealth during an attack and can be accomplished with Bangalore torpedoes and wire cutters.

Cut the Wire

H-77. To cut through a wire obstacle with stealth, —

• Cut only the lower strands and leave the top strand in place, making it less likely the enemy will discover the gap.
• Cut the wire near a picket. To reduce the noise of a cut, have another Soldier wrap cloth around the wire and hold the wire with both hands. Cut part of the way through the wire between the other Soldier’s hands and have him bend the wire back and forth until it breaks. If you are alone, wrap cloth around the wire near a picket, partially cut the wire, and bend and break the wire.

H-78. To reduce an obstacle made of concertina, —

• Cut the wire and stake it back to keep the breach open.
• Stake the wire back far enough to allow room to crawl through or under the obstacle.

Bangalore Torpedo

H-79. After the Bangalore torpedo has been assembled and pushed through the wire obstacle, prime it with either an electric or nonelectric firing system. (See figure H-12, page H-24.) To prevent early detonation of the entire Bangalore torpedo if you hit a mine while pushing it through the obstacle, attach an improvised (wooden) torpedo section to its end. The section can be made out of wooden poles or sticks the size of a real torpedo section. Attach the nose sleeve to the end of the wooden section. Once the Bangalore torpedo has been fired, use wire cutters to cut away wire not cut by the explosion.

Figure H-12. Reducing wire obstacles with Bangalore torpedoes

REDUCE AN URBAN OBSTACLE

H-80. Understanding how to employ and incorporate reduction techniques is an important part of urban operations. Gaining quick access to targeted rooms is integral to room clearing. Reduction teams need to be supported by fires or obscurants. Reduction operations should be performed during hours of limited visibility whenever possible. Reduction techniques vary based on construction encountered and munitions available. The three urban reduction methods discussed in this appendix are mechanical, ballistic, and explosive.

H-81. The assault team’s order of march to the breach point is determined by the method of reduction and its intended actions at the entry point. This preparation must be completed prior to or in the last covered and concealed location before reaching the entry point. Establishing an order of march aids the team leader with mission command and minimizes exposure time in open areas and at the entry point. One order of march technique is to number the assault team members one through four.

H-82. The No. 1 man always should be responsible for frontal and door security. If the reduction has been conducted prior to its arrival, the assault team quickly moves through the entry point. If a reduction has not been made prior to its arrival at the entry point, depending on the type of breach to be made, the team leader conducts the reduction himself or signals forward the breach man or element. One option is to designate the squad leader as the breach man. If the breach man is part of the assault team, he normally will be the last of the four men to enter the building or room. This allows him to transition from his reduction task to his combat role. (Refer to ATTP 3-06.11 for more information.)

BREACH LOCATIONS

H-83. The success of the assault element often depends on the speed with which it gains access into the building. It is important the breach location provide the assault element with covered or concealed access, fluid entry, and ability to be overwatched by the support element.

Creating Mouseholes

H-84. Mouse-holes provide a safe means of moving between rooms and floors. C4 plastic explosive can be used to create mouse-holes when lesser means of mechanical reduction fail. Because C4 comes packaged with an adhesive backing or can be emplaced using pressure-sensitive tape, it is ideal for this purpose. When using C4 to blow a mouse-hole in a lath and plaster wall, one block or a strip of blocks should be placed on the wall from neck-to-knee height. Charges should be primed with detonating cord or modernized demolition initiator (MDI) to obtain simultaneous detonation blowing a hole large enough for a man to fit through.

Expedient Reduction Methods

H-85. Because the internal walls of most buildings function as partitions rather than load-bearing members, smaller explosive charges can be used to reduce them. When C4 or other military explosives are not available, one or more fragmentation grenades or a Claymore can be used to reduce some internal walls. These field-expedient reduction devices should be tamped to increase their effectiveness and to reduce the amount of explosive force directed to the rear. Take extreme care when attempting to perform this type of reduction because fragments may penetrate walls and cause friendly casualties. If walls are made of plaster or dry wall, mechanical reduction may be more effective.

Windows and Restrictive Entrances

H-86. Regardless of the technique used to gain entry, if the breach location restricts fundamental movement into the room or building, local or immediate support must be used until the assault team can support itself. For example, as a Soldier moves through a window and into the room, he may not be in a position to engage an enemy. Therefore, another window having access to the same room may be used to overwatch the lead team’s movement into the room. The overwatching element can come from the initial clearing team or from the team designated to enter the breach location second.

MECHANICAL REDUCTION

H-87. This method requires increased physical exertion by one or more Soldiers using hand tools such as axes, saws, crowbars, hooligan’s tools, or sledgehammers to gain access. Although most Soldiers are familiar with these tools, practice on various techniques increases speed and effectiveness. The mechanical reduction is not the preferred primary method because it may be time-consuming and defeat the element of surprise. However, the ROE and situation may require the use of these tools, so Soldiers should be proficient in their use.

H-88. Typically, the order of movement for a mechanical breach is the initial assault team, followed by the breach man or element. At the breach point, the assault team leader brings the breach team forward while the assault team provides local security. After the reduction is conducted, the breach team moves aside and provides local security as the assault team enters the breach. (Refer to ATTP 3-06.11 for more information.)

H-89. When developing an urban operations mechanical breach kit SOP, Infantry units must consider their mission essential task list (METL) and unit tactical SOPs.

BALLISTIC REDUCTION

H-90. Ballistic reduction requires the use of a weapon firing a projectile at the breach point. Ballistic reduction is not a positive means of gaining entry and should not be considered the primary method for gaining initial entry into a structure. It may not supply the surprise, speed, and violence of action necessary to minimize friendly losses on initial entry. In certain situations, it may become necessary to use ballistic reduction as a back-up entry method. A misfire of an explosive charge or the compromise of the assault element during its approach to the target may necessitate the use of ballistic reduction as a means of initial entry into the structure. Ballistic reduction may have to be followed up with a fragmentation, concussion, or stun grenade before entry.

H-91. Once initial entry is gained, shotgun ballistic reduction may become the primary method for gaining access to subsequent rooms within the structure. Surprise is lost upon initial entry, and other reduction methods are often too slow, tending to slow the momentum of the assault team. If a door must be used for entry, several techniques can be used to open the door. Doors should be considered a fatal funnel because they usually are covered by fire, or may be booby-trapped. (Refer to ATTP 3-06.11 for more information.)

H-92. Unless a deliberate breach is planned, the platoon or squad can employ a series of progressive reductions. An example is an attempt to open a door by using the doorknob first, then shotgun reduction, then explosive reduction as a final option. Mechanical reduction can be used to clean up a failed attempt of a shotgun or explosive reduction, but also can be used as the primary reduction technique. Based on the multiple situations the complex urban environment presents, the leader needs latitude in his options.

Exterior Walls

H-93. For exterior walls, the use of a BFV or artillery piece in the direct fire role is ideal if the structure will support it and if the ROE will allow it. The BFV’s 25-mm cannon is a reduction weapon when using HE rounds and firing a spiral firing pattern. (See figure H-13.) The main gun of an M1-series Abrams tank is effective when using the HEAT round. However, the APDS-T round rarely produces the desired effect because of its penetrating power.

Figure H-13. Spiral firing pattern

Doors, Windows, and Interior Walls

H-94. The M500/M2612-gauge shotgun breaching round is effective on doorknobs and hinges, while standard small arms (5.56 mm and 7.62 mm) have proven to be virtually ineffective for reducing obstacles. These should not be used except as a last resort because of ricochet potential and shoot-through capability. Ballistic reduction of lightly-constructed interior walls by shotgun fire is normally an alternate means of gaining entry.

WARNING
Fragmentation and ricochet effects of standard small arms (5.56 mm and 7.62 mm) as breaching rounds is unpredictable and considered extremely dangerous. Do not attempt in training.

Rifle-Launched Entry Munitions

H-95. Rifle-launched entry munitions (RLEM) allow a remote ballistic reduction of an exterior door or window without having the assault or breaching element physically present at the entry point. This allows the assault element to assume a posture for entry in the last covered and concealed position before the breach. The RLEM shooter is not normally part of the assault element but rather a part of the breaching or support element. This allows the RLEM to be fired from one position while the assault element waits in another position. In the event the first round does not affect the reduction, the firer should prepare a second round for reduction or a second firer should be prepared to engage the target.

WARNING
The firer must be a minimum of 10 meters from the target to safely employ a 150-gram round.

Note. Exact MSDs for firers and assault elements have not been established for the 150-gram round.

Shotgun Reduction

H-96. Various shotgun rounds can be used for ballistic reduction. Breaching and clearing teams need to be familiar with the advantages as well as the disadvantages of each type of round. Leaders must consider the potential for over penetration on walls and floors in multi-story buildings to avoid potential fratricide incidents or killing of noncombatants:

• Rifled slugs. Rifled slugs defeat most doors encountered, including some heavy steel doors. However, rifled slugs present a serious over penetration problem and could easily kill or injure anyone inside the room being attacked. Rifled slugs are excellent AP rounds and can be used accurately up to 100 meters.
• Bird shot. Bird shot (No. 6 through No. 9 shot) is used in close-range work up to 15 meters. A 2 ¾-inch shell of No. 9 shot typically contains an ounce of shot (though it can be loaded to 1 ½-ounce with an accompanied increase in recoil). The major advantage of bird shot is it does not over penetrate. Therefore, bird shot poses little hazard to fellow team members in adjoining rooms. When used at close range, bird shot offers the same killing potential as buckshot, especially in a full choke shotgun intended for dense shot patterns. Another advantage of bird shot is low recoil. This feature allows for faster recovery and quicker multi-target engagements. A disadvantage with bird shot is rapid-energy bleed-off reducing penetration at medium and long ranges. Moreover, the small size of the individual pellets requires hits be made with a majority of the shot charge to be effective. A hit with one-third of the No. 9 shot charge may not be fatal, unless the shot is at extremely close range. These disadvantages are negated when birdshot is fired from a full choke shotgun where it will produce a pattern quite small inside of 10 meters. Inside five meters, all of the shot will be clumped like a massive single projectile.
• Buckshot. Buckshot is used in close- to medium-range work, up to 30 meters. Because of its larger size, buckshot is more lethal than bird shot. A 2 ¾-inch shell of buckshot contains nine .30-caliber pellets. One .30-caliber ball of the 00 buckshot charge hit can prove fatal. Buckshot also retains its energy longer. Therefore, it is lethal at longer ranges than bird shot. A disadvantage of buckshot is over penetration. Because buckshot typically is loaded with heavier shot charges, it also has heavy recoil. This problem becomes apparent when numerous shots have been taken and can result in fatigue.
• Ferret rounds. Ferret rounds contain a plastic slug filled with liquid chemical irritant (CS). When shot through a door or wall (drywall or plywood), the plastic slug breaks up and a fine mist of CS is sprayed into the room. The effectiveness of one round is determined by the size of the room on the other side of the door or the wall and also the ventilation in that room.
• When using the shotgun as an alternate reduction method to gain entry, shooters must consider the following target points on the door.
• Doorknob. Never target the doorknob itself because when the round impacts, the doorknob has a tendency to bend the locking mechanism into the doorframe. In most cases this causes the door to be bent in place and prevents entry into the room.
• Locking mechanism. When attacking the locking mechanism, focus the attack on the area immediately between the doorknob and doorframe. Place the muzzle of the shotgun no farther than one inch away from the face of the door directly over the locking mechanism. The angle of attack should be 45 degrees downward and at a 45-degree angle into the doorframe. After breaching the door, kick it swiftly. This way, if the door is not completely open, a strong kick usually will open it. When kicking the door open, focus the force of the kick at the locking mechanism and close to the doorjamb. After the locking mechanism has been reduced, this area becomes the weakest part of the door.
• Hinges. The hinge breach technique is performed much the same as the doorknob reduction, except the gunner aims at the hinges. He fires three shots per hinge, the first at the middle, then at the top and bottom. He fires all shots from less than an inch away from the hinge. Because the hinges are often hidden from view, the hinge reduction is more difficult. Hinges are generally 8 to 10 inches from the top and bottom of the door. The center hinge is generally 36 inches from the top, centered on the door. Regardless of technique used, immediately after the gunner fires, he kicks the door in or pulls it out. He then pulls the shotgun barrel sharply upward and quickly turns away from the doorway to signal the breach point has been reduced. This rapid clearing of the doorway allows the following man in the fire team a clear shot at enemy who may be blocking the immediate breach site. (Refer to ATTP 3-06.11 for more information.)

H-97. When the assault team members encounter a door to a “follow-on” room, they should line up on the side of the door giving them a path of least resistance upon entering. When the door is encountered, the first Soldier to see it calls out the status of the door, OPENED or CLOSED. If the door is open, Soldiers should never cross in front of it to give themselves a path of least resistance. If the door is closed, the No. 1 man maintains security on the door and waits on the No. 2 man to gain positive control of the No.1 man. The No. 1 man begins the progressive breaching process by taking his nonfiring hand and checking the doorknob to see if it is locked. If the door is unlocked, the No. 1 man (with his hand still on the door) pushes the door open as he enters the room. If the door is locked, the No. 1 man releases the doorknob (while maintaining security on the door) and calls out the breacher, BREACHER UP.

H-98. Once the breacher arrives at the door (with round chambered), he places the muzzle of the shotgun at the proper attack point, takes the weapon off safe, and signals the No. 2 man by nodding his head. At that time, the No. 2 man (with one hand maintaining positive control of the No. 1 man) takes his other hand (closest to the breacher) and forming a fist, places it within the periphery of the breacher and pumps his fist twice saying, READY BREACH. This action allows the breacher to see if a flash-bang or grenade is to be used. Once the breacher defeats the door, he steps aside and allows the assault team to enter. He then either assumes the position of the No. 4 man if he is acting as a member of the assault team or remains on-call as the breacher for follow-on doors. He should keep the shotgun magazine full at all times. There may be several doors, and stopping to reload will slow the momentum of the assault.

Note. The shotgun should not be used as a primary assault weapon because of its limited magazine capacity and difficulty of reloading.

Exterior Walls

H-99. One of the most difficult breaching operations of the assault team is reducing masonry and reinforced concrete walls. C4 normally is used for explosive reduction because it is safe, easy to use, and readily available. Engineers usually are attached to the platoon or squad if explosive reduction operations are expected. The attached engineers will conduct the reduction themselves or provide technical assistance to the Infantry Soldiers involved. The typical thickness of exterior walls is 15 inches or less, although some forms of wall construction are several feet thick. Assuming all outer walls are constructed of reinforced concrete, a rule of thumb for reduction is to place 10 pounds of C4 against the target between waist and chest height. When detonated, this charge normally blows a hole large enough for a man to go through. On substandard buildings, however, a charge of this size could level the building. When explosives are used to reduce windows or doors, the blast should eliminate IEDs in the vicinity of the window or doorframe. (Refer to ATTP 3-06.11 for more information.)

Note. Not all charges are mentioned in this manual, only the most commonly used by Infantry Soldiers. (Refer to ATP 3-34.20 for more information.)

Charge Placement

H-100. Place the charges (other than shape charges) directly against the surface to be reduced. When enemy fire prevents an approach to the wall, a potential technique is to attach the charge, untamped, to a pole and slide it into position for detonation at the base of the wall. Small-arms fire will not detonate C4 or TNT. Take cover before detonating the charge.

Tamping

H-101. Whenever possible, explosives should be tamped or surrounded with materiel to focus the blast to increase effectiveness. Tamping materiels could be sandbags, rubble, desks, chairs, and even intravenous bags. For many exterior walls, tamping may be impossible due to enemy fire. An untamped charge requires approximately twice the explosive charge of a tamped charge to produce the same effect.

Second Charges

H-102. Charges will not cut metal reinforcing rods inside concrete targets. If the ROE permit, hand grenades should be thrown into the opening to clear the area of enemy. Once the area has been cleared of enemy, the reinforcing rods can be removed using special steel-cutting explosive charges or mechanical means.

Door Charges

H-103. Various charges can be utilized for explosive reduction of doors. Leaders must conduct extensive training on the use of the charges to get proper target feedback.

H-104. The general-purpose charge, rubber band charge, and flexible linear charge are field-expedient charges that can be used to reduce interior and exterior doors. These charges give the breach element an advantage because they can be made ahead of time and are simple, compact, lightweight, and easy to emplace. (Refer to ATTP 3-06.11 for more information.)

General-Purpose Charge

H-105. This charge is the most useful ready charge for reducing a door or other barrier. It can cut mild steel chain and destroy captured enemy equipment. To construct the general purpose charge—

• Take a length of detonation cord about two feet long. Using another length of detonation cord, tie two uli knots around the 2-foot long cord.
• The uli knots need to have a minimum of six wraps and be loose enough for them to slide along the main line, referred to as an uli slider.
• Trim the excess cord from the uli knots and secure them with tape.
• Cut a block of C4 explosive to a two-inch square.
• Tape one slider knot to each side of the C4 block, leaving the length of detonation cord free to slide through the knots.

H-106. To place the charge, perform the following:

• To reduce a standard door, place the top loop of the charge over the doorknob. Slide the uli knots taped to the C4 so the charge is tight against the knob.
• Prime the loose ends of the detonation cord with an MDI firing system and detonate.

Note. To cut mild steel chain, place the loop completely around the chain link to form a girth hitch. Tighten the loop against the link by sliding the uli knots.

Rubber Band Charge

H-107. The rubber band charge is an easily fabricated lightweight device that can be used to remove the locking mechanism or doorknob from wooden/light metal doors, or to break a standard-size padlock at the shackle. To construct the rubber band charge, —

• Cut a 10-inch piece of detonation cord and tie an overhand knot in one end.
• Using another piece of detonation cord, tie an uli knot with at least eight wraps around the first length of cord.
• Slide the uli knot tightly up against the overhand knot. Secure it in place with either tape or string.
• Loop a strong rubber band around the base of the uli knot tied around the detonation cord.
• Tie an overhand knot in the other end of the cord to form a pigtail for priming the charge.

H-108. To place the charge, attach the charge to the doorknob (or locking mechanism) by putting the loose end of the rubber band around the knob. The charge must be placed between the knob and doorframe. This ensures the explosive is over the bolt securing the door to the frame.

Flexible Linear Charge

H-109. The simplest field-expedient charge for reducing wooden doors is the flexible linear charge. (See Tables H-3 and H-4 (page H-34) for charge use and system components.) It can be made in almost any length and is easily carried until needed. It is effective against hollow-core, particle-filled, and solid wood doors. When detonated, the flexible linear charge cuts through the door near the hinges

H-110. To construct the flexible linear charge, lay out a length of double-sided contact tape with the topside adhesive exposed. Place the necessary number of strands of detonation cord down the center of the double-sided tape, pressing them firmly in place. Military detonation cord has 50 grains of explosives per foot and 7,000 grains in a pound. Most residential doors are 80 inches tall. Commercial doors are 84 inches tall. This must be considered when calculating the quantities of explosives, overpressure, and MSDs. For hollow-core doors, use a single strand; for particle-filled doors, use two strands; and for solid wood doors, use three strands. If the door type is unknown, use three strands. One of the strands must be cut about a foot longer than the others and should extend past the end of the double-sided tape. This forms a pigtail where the initiating system is attached once the charge is in place. Cover the strands of detonation cord and all the exposed portions of the double-sided tape with either sturdy single-sided tape or another length of double-sided tape. Roll the charge, starting at the pigtail, with the double-sided tape surface to be placed against the door on the inside.

H-111. At the breach site, place the charge straight up and down against the door tightly. If it is too short, place it so it covers at least half of the door’s height. Prime and fire the charge from the bottom.

Table H-3. Charges

Table H-3. Charges (continued)

Table H-4. Firing system components

Explosive Safety Factors

H-112. When employing explosives during breaching operations, leaders must consider three major safety factors: overpressure; missile hazard; and MSD requirements.

Overpressure

H-113. Overpressure is the pressure per square inch (PSI) released from the concussion of the blast. Both outside and into the interior of the building or room, which can injure, incapacitate, or kill.

Missile Hazard

H-114. Missile hazards are fragmentation or projectiles sent at tremendous speed from the explosion area. This occurs from either the charge or target being breached.

Minimum Safe Distance Requirements

H-115. When using explosives in the urban environment, Soldiers must consider the presence of noncombatants and friendly forces. Additionally, there are many hazardous materiel’s located in the urban environment, including CBRN and construction materiel’s. There is always a risk of secondary explosions and fires when employing explosive breaching techniques.

CAUTION
Always handle explosives carefully. Never divide responsibility for preparing, placing, priming, and firing charges. Always use proper eye and ear protection and cover exposed skin to prevent injuries. Explosives may produce hazardous fumes, flames, fragments, and overpressure. Use AR 385-63, FM 3-34.214, and risk assessment to determine MSDs. Take into consideration whether the door is flush or receded when considering MSD.

REDUCE IMPROVISED EXPLOSIVE DEVICES

H-116. Soldiers must be aware of the threat presented by IEDs that can be found in an operational environment in which the platoon or squad might operate. The platoon and squad must receive sufficient training to recognize locations and items lending themselves to booby-trapping, striking a balance between what is possible and what is probable. (Refer to ATP 3-34.20 for more information.)

Note. Whenever mission variables allow call EOD or engineers for removal of IEDs.

H-117. When dealing with IEDs, the following rules and safety procedures can save lives:

• Suspect objects appearing to be out of place or artificial in its surroundings. Remember, what you see may well be what the enemy wants you to see. If you did not put it there, do not pick it up.
• Examine mines and IEDs from all angles, and check for alternative means of detonating before approaching them.
• Ensure only one man works on a booby trap.
• Do not use force. Stop if force becomes necessary.
• Do not touch a trip wire until both ends have been investigated and all devices are disarmed and neutralized.
• Trace trip wires and check for additional traps along and beneath them.
• Treat all parts of a trap with suspicion, because each part may be set to actuate the trap.
• Wait at least 30 seconds after pulling a booby trap or a mine. There might be a delay fuse.
• Mark all traps until they are cleared.
• Expect constant change in enemy techniques.
• Never attempt to clear IEDs by hand if pulling them or destroying them in place is possible and acceptable.

H-118. IEDs might be found in recently contested areas, so no items or areas that have not been cleared should be considered safe. By anticipating the presence of traps, it might be possible to isolate and bypass trapped areas. If this is not possible, employ countermeasures such as avoiding convenient and covered resting places along routes where mines or other explosive devices can be located. Collective training in booby-trap awareness and rapidly disseminating booby-trap incident reports to all levels is vital. This allows Soldiers to develop an understanding of the enemy’s method of operation and a feel for what might or might not be targets.

INDICATIONS AND DETECTION

H-119. Detection depends on two things: being aware of what might be trapped and why, and being able to recognize the evidence of setting. The first requirement demands a well-developed sense of intuition; the second, a keen eye. Intuition is gained through experience and an understanding of the enemy’s techniques and habits. A keen eye is the result of training and practice in the recognition of things indicating the presence of a trap.

H-120. Detection methods depend on the nature of the environment. In open areas, methods used to detect mines can usually detect IEDs. Look for trip wires and other signs suggesting the presence of an actuating mechanism. In urban areas, mine detectors are probably of little use. The platoon and squad will have to rely on manual search techniques and, if available, special equipment. The presence of IEDs or nuisance mines is indicated by—

• Disturbance of ground surface or scattered, loose soil.
• Wrappers, seals, loose shell caps, safety pins, nails, and pieces of wire or cord.
• Improvised methods of marking traps, such as piles of stones or marks on walls or trees.
• Evidence of camouflage, such as withered vegetation or signs of cutting.
• Breaks in the continuity of dust, paint, or vegetation.
• Trampled earth or vegetation; foot marks.
• Lumps or bulges under carpet or in furniture.

REDUCTION METHODS

H-121. Reducing IEDs and nuisance mines in area of operation is done primarily by engineers, especially in secured areas. However, some IEDs may have to be cleared by Infantry Soldiers to accomplish a mission during combat. The method used to disarm a trap depends on many things including, time constraints, personnel assets, and type of trap. A trap cannot be considered safe until the blasting cap or the detonation cord has been removed from the charge.

H-122. Use the safest method available to neutralize a trap. For example, if the firing device and detonation cord are accessible, it is usually safer to cut the detonation cord. This method does not actuate the trap, but inserting pins in the firing device might. Unit resources or locally-manufactured or acquired aids often are used to clear traps. In areas with a high incidence of IEDs, assemble and reserve special clearing kits. Mark all IEDs found.

H-123. Nonexplosive traps typically are used in tropical or rain forest regions. Ideal construction materiels abound and concealment in surrounding vegetation is relatively easy. No prescribed procedures exist for clearing nonexplosive traps. Each trap must be cleared according to its nature.

SECTION III – OBSTACLE EMPLOYMENT

H-124. Obstacles are used to reinforce the terrain. When combined with fires, they disrupt, fix, turn, or block an enemy force. Obstacles are used in all operations, but are most useful in defensive missions. Leaders must always consider what materiels are needed and how long the obstacle will take to construct. (Refer to ATTP 3-90.4 for more information.)

H-125. A primary concern of the platoon and squad in the defense is to supplement their fortified positions with extensive protective obstacles, both antipersonnel and antivehicular (particularly AP). AP obstacles, both explosive and nonexplosive, include all those mentioned in Section I of this chapter (such as wire entanglements, AP mines, and field expedient devices), and are used to prevent enemy troops from entering a friendly position. Antipersonnel obstacles usually are integrated with fires and are close enough to the fortification for adequate surveillance by day or night, but beyond effective hand grenade range. Obstacles also are used within the position to compartmentalize the area in the event outer protective barriers are breached.

H-126. In the offense, the platoon/squad uses obstacles to:

• Aid in flank security.
• Limit enemy counterattack.
• Isolate objectives.
• Cut off enemy reinforcement or routes of withdrawal.

H-127. In the defense, the platoon/squad uses obstacles to—

• Slow the enemy’s advance to give Infantry platoons and squads more time to mass fires on them.
• Protect defending units.
• Canalize the enemy into places where he can be engaged more easily.
• Separate the enemy’s tanks from its Infantry.
• Strengthen lightly defended areas.

MINES

H-128. A mine is an explosive device employed to kill, destroy, or incapacitate enemy personnel and equipment. Mines can be employed in quantities within a specific area to form a minefield, or they can be used individually to reinforce nonexplosive obstacles. Equipment targets include ground vehicles, boats, and aircraft. Land mines fall into the following two general categories:

• (U) Persistent
• (U) Non-Persistent

H-129. Within each of these categories, the mines and munitions can be more clearly defined as antitank or antipersonnel. Mines are one of the most effective tank killers on the battlefield. The type of minefield that a platoon or squad most commonly emplaces is the hasty protective. It is important to distinguish the difference between the types of minefield and means of emplacement. Volcano, MOPMS, standard-pattern, and row mining are not types of minefields; they are just some of the means used to emplace tactical, situational, nuisance, and protective minefields. They also may be the method of emplacement that is replicated by a phony minefield.

Note. U.S. forces are not authorized to employ persistent mines, except in Korea. Some countries employ AHDs on antipersonnel mines, but U.S. forces are not authorized to employ AHDs on antipersonnel mines, except in Korea.

H-130. The United States will—

• Not use APL outside the Korean Peninsula.
• Not assist, encourage, or induce anyone outside the Korean Peninsula to engage in activity prohibited by the Ottawa Convention; and undertake to destroy APL stockpiles not required for the defense of the Republic of Korea.

H-131. Land-based mines and munitions are hand-emplaced, remote-delivered, air-delivered, or ground-delivered. (See table H-5.) ATP 3-34.20 provides detailed instructions on the installation and removal of U.S. mines and firing devices.

Table H-5. Mine delivery methods

SCATTERABLE MINES

H-132. SCATMINEs are laid without regard to a classical pattern. They are designed to be delivered remotely by aircraft, artillery, missile, or a ground dispenser. All U.S. SCATMINEs have a limited active life and self-destruct after life has expired. The duration of the active life varies with the type of mine and delivery system.

H-133. SCATMINEs enable minefield emplacement in enemy-held territories, contaminated territories, and in most other areas where it is impossible for engineers, the platoon or squad to emplace countermobility obstacles. They may be used to support the platoon’s and squad’s mission by turning, fixing, disrupting, and blocking the enemy. However they are used, they must be planned and coordinated to fit into the overall obstacle plan. (Refer to ATP 3-90.8 for more information.)

Modular Pack Mine System, Man-Portable

H-134. The man-portable, 162-pound, suitcase-shaped MOPMS dispenses a total of 21 mines (17 AT mines and 4 AP mines). It propels them in a 35-meter, 180-degree semicircle from the container. Mines are dispensed on command using the M71 remote control unit (RCU) or an electronic initiating device such as the M34 blasting machine. When dispensed, an explosive propelling charge at the bottom of each tube expels mines through the container roof. (See figure H-14, page H-40.)

H-135. Infantry platoons and squads can use MOPMS to create a protective minefield or to close lanes in tactical obstacles. The safety zone around one container is 55 meters to the front and sides, and 20 meters to the rear. MOPMS has duration of four hours, which can be extended up to three times for a total of 16 hours. Once mines are dispensed, they cannot be recovered or reused. If mines are not dispensed, the container may be disarmed and recovered for later use. The RCU also can self-destruct mines on command, allowing a unit to counterattack or withdraw through the minefield. The RCU can control up to 15 MOPMS containers or groups of MOPMS containers from a distance of 300 to 1000 meters.

Figure H-14. Modular pack mine system

CONVENTIONAL MINES

H-136. Conventional mines are hand-emplaced mines requiring manual arming. This type of mine laying is labor, resource, and transport-intensive. Soldiers emplace conventional mines within a defined, marked boundary and lay them individually or in clusters. They record each mine location so the mines can be recovered. Soldiers can surface lay or bury conventional mines and may place AHDs on antitank mines.

Note. The United States will—

• Not use APL outside the Korean Peninsula;
• Not assist, encourage, or induce anyone outside the Korean Peninsula to engage in activity prohibited by the Ottawa Convention; and
• Undertake to destroy APL stockpiles not required for the defense of the Republic of Korea.

Antitank Mines

H-137. The M15 and M21 AT mines are used by U.S. forces. They are shown in figure H-15. Their characteristics are listed in table H-6 (page H-42).

Figure H-15. Antitank mines

Table H-6. Characteristics of antitank mines

Antipersonnel Mines

H-138. The M14 and M16 AP mines are used by U.S. forces on the Korean Peninsula. They also are used by many other countries. These mines are shown in figure H-16. Their characteristics are listed in table H-7.

Figure H-16. Antipersonnel mines

Table H-7. Characteristics of antipersonnel mines

SPECIAL-PURPOSE MUNITIONS

H-139. Special-purpose munitions the platoon or squad might employ include the M18A1 Claymore and selectable lightweight attack munitions (SLAM).

M18A1 CLAYMORE

H-140. The M18A1 Claymore (see figure H-17) is a fragmentation munitions containing 700 steel balls and 682 grams of composition C4 explosive. It weighs 1.6 kilograms and is command-detonated.

H-141. When employing the Claymore with other munitions or mines, separate the munitions by the following minimum distances:

• Fifty meters in front of or behind other Claymores.
• Three meters between Claymores placed side by side.
• Ten meters from antitank or fragmentation antipersonnel munitions.
• Two meters from blast antipersonnel munitions.

Figure H-17. M18A1 Claymore

SLAM

H-142. The M4 SLAM is a multipurpose munitions with an anti-tamper feature. (See figure H-18.) It is compact and weighs only a kilogram. It is easily portable and is intended for use against armored personnel carriers, parked aircraft, wheeled or tracked vehicles, stationary targets (such as electrical transformers), small (less than 10,000 gallon) fuel-storage tanks, and ammunition storage facilities. The explosive formed penetrator warhead can penetrate 40 millimeters of homogeneous steel. The SLAM has two models (the self-neutralizing [M2] and self-destructing [M4]). The SLAM’s four possible employment methods include: bottom attack, side attack, timed demolition, and command detonation.

Figure H-18. Selectable lightweight attack munitions

M93 HORNET

H-143. The Hornet is a man-portable, nonrecoverable, AT/antivehicular, off-route munitions made of lightweight materiel (35 pounds) one person can carry and employ. It is capable of destroying vehicles by using sound and motion detection methods. It will automatically search, detect, recognize, and engage moving targets by using top attack at a standoff distance up to 100 meters. It can be a stand-alone tactical obstacle or can reinforce other conventional obstacles. (See figure H-19, page H-46.)

H-144. It disrupts and delays the enemy, allowing long-range, precision weapons to engage more effectively. This feature is particularly effective in non-LOS engagements. It normally is employed by combat engineers, Rangers, and SOF. The RCU is a handheld encoding unit interfacing with the Hornet when the remote mode is selected at the time of employment. After encoding, the RCU can be used to arm the Hornet, reset its self-destruct times, or destroy it. The maximum operating distance of the RCU is two kilometers.

Figure H-19. M93 Hornet

NETWORKED MUNITIONS

H-145. Networked munitions are designed to leverage our network centric fighting abilities. Ground-emplaced networked munitions are recoverable, reusable, and scalable. Existing fields may be reseeded and will accept added munitions into the network. Field sizes may vary from small, hasty protective fields to larger tactical fields. The network provides remote control, situational understanding, various attack modes, and various employment means. All networked munitions have self-destruct features.

FEATURES

H-146. Remote control, in barrier operations, is the ability of a user to actuate a charge or change the state of a mine from a distance. Remote control features include:

• ON-OFF-ON.
• Command destruct.
• Variable self-destruct features.
• Select lethal or nonlethal effects.
• Anti-tamper or anti-spoofing.
• Unmanned sentinel.

H-147. Situational-understanding features include:

• Field or munitions status.
• Field or munitions location.
• Alert to approaching friendly forces.
• Report battle damage information (intelligent munitions system).
• Cue other fire systems (intelligent munitions system).

H-148. Employment means include:

• Hand-emplaced (Spider system, intelligent munitions system).
• Mechanically dispensed (intelligent munitions system).
• Remotely delivered (out to 15 kilometers) (intelligent munitions system).

H-149. Networked munitions support assured mobility by providing the following capabilities:

• Detects and neutralizes the enemy force.
• Covers gaps and prevents enemy maneuver.
• Provides economy of force.
• Protects friendly forces.
• Provides immediate, selective engagement.

H-150. The capabilities of networked munitions will provide for unprecedented assured mobility. By leveraging the network and various employment means, networked munitions will support seamless transitions from the offense to stability. Given positive remote control, there is no longer the danger of impeding our own mobility. Hence, the authority for emplacement may be pushed down to lower tactical levels. (Refer to ATP 3-34.20 for more information.)

HASTY PROTECTIVE MINEFIELDS

H-151. Units report protective obstacles through their chain of command to their higher level headquarters. If the higher headquarters has authorized the use of protective obstacles in the ROE, tactical SOP, or OPORD, subordinate units are not required to submit a report of intention. Units establish SOPs for reporting initiation, progress, and completion of protective obstacles to the battalion level.

H-152. Individual units emplace and remove their own protective obstacles. Therefore, it is usually not necessary for the emplacing unit to turn over the obstacle to the overwatching force. If a nonorganic emplacing unit, such as an engineer platoon, emplaces the protective obstacle, the emplacing unit transfers the obstacle. Units mark protective minefields on all four sides. Units mark lanes and gaps according to ATTP 3-90.4. Commanders decide whether to mark other inherently dangerous obstacles based on the risk assessment. Protective munition fields are recorded using a +DD Form 3007 (Hasty Protective Row Minefield Record) as shown in figure H-20 (page H-48). Protective minefields are recorded using a scatterable minefield record. (Refer to JP 3-15 and ATP 3-34.20 for more information.)

+Figure H-20. Example DD Form 3007 (Hasty Protective Row Minefield Record)

H-153. Units also depict protective minefields and munition fields on their sector sketches. If the minefield or munition field is transferred to another unit, the transferring unit leader briefs the receiving unit leader and provides the necessary obstacle records. If the minefield or munition field is abandoned unexpectedly, the unit forwards the record to higher headquarters. (Refer to ATP 3-90.8 for more information on protective obstacles.)

WIRE OBSTACLES

H-154. The platoon or squad normally employs wire obstacles as part of the protective obstacle plan in the defense. Wire obstacles include barbed-wire, triple-standard concertina, four-strand cattle fences, and tanglefoot. Construction methods for two of the more common wire obstacles the platoon or squad employs, triple standard concertina, and tanglefoot are shown in figures H-21 through H-25 (pages H-50 through H-52). (Refer to ATTP 3-90.4 for more information.)

TRIPLE STANDARD CONCERTINA FENCE

H-155. The most common wire entanglement a platoon or squad may build is the triple standard concertina fence. It is built of either barbed wire concertina or barbed tape concertina. There is no difference in building methods. The material and labor requirements for a 300-meter triple standard concertina fence are—

• Long pickets – 160.
• Short pickets – 4.
• Barbed wire, 400-meter reels – 3.
• Rolls of concertina – 59.
• Staples – 317.
• Man-hours to erect – 30.

H-156. First, lay out and install pickets from left to right (facing the enemy). Put the long picket’s five paces apart and short (anchor) picket’s two paces from the end of the long pickets. (See figure H-21, page H-50.) The enemy and friendly picket rows are offset and are placed three feet apart. Now lay out rolls of concertina. Place a roll in front of the third picket on the enemy side, and two rolls to the rear of the third picket on the friendly side. Repeat this step every fourth picket thereafter. Install the front row concertina and horizontal wire. (See figure H-22, page H-50.) Place the concertina over the pickets. Install the rear row of concertina and horizontal wire. Install the top row of concertina and join the rear horizontal wire. (See figure H-23, page H-50.)

Figure H-21. Triple standard concertina fence

Figure H-22. Installing concertina

Figure H-23. Joining concertina

CONCERTINA ROADBLOCK

H-157. The concertina roadblock is placed across roadways and designed to block wheeled or tracked vehicles. The roadblock is constructed of 11 concertina rolls or coils placed together, about 10 meters in depth, reinforced with long pickets five paces apart. The rolls or coils should not be tautly bound allowing them to be dragged and tangled around axles, tank road wheels, and sprockets. Additionally, wire is placed horizontally on top of the concertina rolls or coils. (See figure H-24.)

Figure H-24. Eleven-row anti-vehicular wire obstacle

TANGLEFOOT

H-158. Tanglefoot is used where concealment is essential and to prevent the enemy from crawling between fences and in front of emplacements. (See figure H-25, page H-52.) The obstacle should be employed in a minimum width of 32 feet. The pickets should be placed at irregular intervals of 2 ½ feet to 10 feet. The height of the barbed wire should vary between 9 to 30 inches. Tanglefoot should be sited in scrub, if possible, using bushes as supports for part of the wire. On open ground, short pickets should be used.

Figure H-25. Tanglefoot