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					                                                                                                              FM 7-7

                                             APPENDIX P
                                   Section I. MINEFIELDS

  Minefields assist in security defensive, retro-   sponsibility for the minefield to the relieving
grade, and offensive operations by reducing the     platoon leader.
mobility of the enemy. Minefields supplement             Only metallic mines are used in hasty pro-
obstacles and weapons. They also add to the         tective minefields. A metallic mine detector
user’s combat power without adding more troop       (AN/PSS-11) will help locate them. The mine
strength.                                           detectors are in the battalion’s supply section.
  Characteristics and techniques for employ-        Booby traps are not used in hasty protective
ment of antipersonnel and antitank mines are        minefield; they delay removal of the mines.
shown in illustration. (Fig. P-1.)                  Time may allow only the placing of mines on
                                                    the surface of the ground when laying hasty
P-2. HASTY PROTECTIVE MINEFIELD                     minefield.
   In the defense, platoons and squads lay hasty         The employing unit must make sure that
protective minefield to supplement weapons,         the minefield can be kept under observation and
prevent surprise, and give early warning of en-     covered by fire at all times. Continuous observa-
                                                    tion can keep the enemy from booby-trapping,
emy advance. A platoon can install hasty pro-       removing, or easily bypassing the mines.
tective minefield, but only with permission
from the company commander. (The company               The following example describes how to lay a
commander must get permission from the bat-         hasty protective minefield. Although this is an
talion commander.)                                  example for a platoon, a squad follows the same
      Hasty protective minefield are reported to    procedure.
the company commander, recorded on DA Form               The platoon has moved into a battle posi-
1355-1, and marked. The leader puts the mine-       tion and is preparing to defend. Hasty protec-
field across likely avenues of approach, within     tive minefield are needed to improve the
range of his organic weapons and within visual      defense. The platoon’s basic load contains M21
observation from his defensive positions.           antitank mines, and M16A1 and M18A1 (Clay-     -
                                                    more) antipersonnel mines with tripwires.
      The minefield should be recorded before the
mines are armed. The leader installing the
minefield should warn adjacent platoons and           CONTENTS                                                    PAGE
tell the company commander of the minefield’s         Section I. Minefield . . . . . . . . . . . . . . . . . . . . . . . P-1
                                                             II. Wire and Demolitions . . . . . . . . . . P-10
location. When the platoon leaves the area (ex-             III. Breaching and
cept when forced to withdraw by the enemy), it                     Clearing Ostacles . . . . . . . . . . . P-21
must remove the minefield or transfer the re-

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     After requesting and receiving permission   squad leaders reconnoiter to determine exactly
to lay the minefield, the platoon leader and     where the mines should be placed.

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    The leaders find a need to use antitank
mines to block enemy vehicles at two points — a
bridge and a ford (see figure).

                                                        The firing wire for the Claymore will be
                                                    camouflaged using grass or leaves, and it will
                                                    be buried when possible.

    The leaders decide that antipersonnel             When the leaders have decided exactly .where
mines are needed to protect the antitank mines      they will lay the mines, and are ready to begin,
and to cover the likely avenues of approach of      the platoon leader reports this information to
enemy infantry. Antipersonnel mines are also        the company commander. This is called an initi-
needed for the open area in front of the platoon.   ation report. Next, squad leaders have their
The M16A1 antipersonnel mines will be buried,       men emplace the mines. THE TROOPS DO
time permitting, and the tripwires camou-           NOT ARM OR ATTACH TRIPWIRES TO THE
flaged with grass or leaves.                        MINES AT THIS TIME.

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              While the troops are placing the mines, the
         platoon leader finds an easily identifiable refer-
         ence point in front of the platoon’s position. In
         this example, he decides the concrete post to the
         front is an ideal reference point. The platoon
         leader now starts to record the minefield.
              At the reference point, the platoon leader
         tries to visualize the minefield running in rows
         parallel to the defensive position. This will
         make the recording simpler and will later make
         retrieval quicker and safer. The row of mines
         closest to the enemy is designated A and the
         succeeding rows will be B, C, etc. For this hasty
         protective minefield, the platoon leader decides
         that two rows (A and B) will be enough.

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     The ends of a row are shown by two mark-        in the row can be an antitank mine to facilitate
ers. They are labeled with the letter of the row     its retrieval. The form now looks like Fig. P-8.
and the number 1 for the right end of the row
and 2 for the left end of the row. The rows are           The platoon leader now ties in the reference
numbered from right to left, facing the enemy        point with a permanent landmark that he found
The marker can be a wooden stake or steel            on the map if available. He measures the dis-
picket.                                              tance and azimuth from this landmark to the
                                                     reference point. The landmark might be used to
    From the concrete post, the platoon leader       help others locate the minefield should it be
measures the magnetic azimuth in degrees and         abandoned. Finally he completes the tabular
paces the distance to a point arbitrarily selected   and identification blocks. The completed form
between 15 and 25 paces to the right of the first    looks like Fig. P-9.
mine on the friendly side of the minefield. This
point is B-1 and marks the beginning of the                    While the platoon leader is tying
second row of mines. The platoon leader places a          in the landmark, the troops arm the
marker at B-1 and records the azimuth and dis-            mines. The troops arm the mines near-
tance from the concrete post to B-1 on DA Form            est the enemy first (row A). This lets
1355-1-R Fig. P-6.                                        the troops work their way back to the
                                                          platoon position safely
      Next, the platoon leader measures the az-
imuth and distance to a point 15 to 25 paces                  Now that the field is laid and the
from the first mine in row A. He places a                 paperwork is done, the platoon leader
marker at this point and records it as A-1. (Fig.         calls the commander and reports that
P-7.)                                                     the minefield is completed.
    The platoon leader then measures the dis-          As long as the unit and the minefield stay in
tance and azimuth from A-1 to the first mine in      place, the form (DA Form 1355-1-R) stays with
row A and records them. He then measures the         the platoon leader. If the minefield is trans-
distance and azimuth from the first mine to the      ferred to another platoon, the gaining platoon
second, and so on until all mine locations have      leader signs and dates the “mines transferred”
been recorded, as shown.                             block and accepts the form from the previous
                                                     platoon leader. When the minefield is removed,
  The platoon leader gives each mine a number        the form is destroyed. If the minefield is left
to identify it in the tabular block of DA Form       unattended or abandoned unexpectedly, the
1355-1-R.                                            form must be forwarded to the company com-
                                                     mander. The company commander forwards it to
    When the last mine location in row A is          battalion to be transferred to more permanent
recorded, the platoon leader measures an az-         records. In summary the steps for installing a
imuth and distance from the last mine to an-         hasty protective minefield are:
other arbitrary point between 15 and 25 paces
beyond the last mine. He places a marker here                 (1) Report intention to lay a hasty
and calls it A-2. The platoon leader follows this         protective minefield and get author-
same procedure with row B.                                ization to lay it.
     When the platoon leader finishes recording               (2) Reconnoiter to find the best
and marking the rows, he measures the dis-                places for mines based on likely en-
tance and azimuth from the reference point to             emy avenues of approach and the pla-
B-2, and from B-2 to A-2, and records them. If            toon’s ability to keep the mines under
the tactical situation requires it, the last mine         observation.

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162-169 0 - 94 - 12
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     (3) Report starting of the mine-   mines yet. Use only metallic mines. Do
field.                                  not use booby trap devices.
     (4) Have the mines placed on the       (5) Record the minefield on DA
avenues of approach. Do not arm the     Form 1355-1-R.

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          (6) Arm the mines, working from           then move from B-1 to the first mine in row B.
     the enemy side to the friendly side.           However, if B-1 is destroyed, they move from the
          (7) Report completion of the mine-        reference point to B-2, using that azimuth and
     field.                                         distance. They will now have to shoot the back
                                                    azimuth from B-2 to the last mine, i.e., add or
          (8) Always integrate mines with           subtract 180 degrees from the recorded az-
     other defense plans.                           imuth. The stakes at A-1 and B-1 are required.
  When retrieving the mines, the troops start       Stakes at A-2 and B-2 are recommended because
at the reference point and move to B-1, using       it is safer to find a stake when traversing long
the azimuth and distances as recorded. They         distances than to find a live mine.

                        Section II. WIRE AND DEMOLITIONS
  Engineers normally have the responsibility        build, the most common is the triple standard
and equipment for assisting the infantry in con-    concertina fence. It is built of either barbed wire
structing wire and demolition obstacles. The        concertina or barbed tape concertina. There is
shortage of engineers, however, may require         no difference in building methods.
that rifle platoons and squads build these obsta-      The material and labor requirements for a
cles as best they can. Obstacles should be:         300-meter triple standard concertina fence are
         Under friendly observation and cov-        listed below.
      ered by fire.                                                160           long pickets
         Concealed from enemy observation                             4          short pickets
      as much as possible.                                            3          400-meter reels of
                                                                                 barbed wire
         Erected in an irregular pattern.                            59          rolls of concertina
         Employed in depth.                                        317           staples
                                                                    30           man-hours to erect
         Coordinated with existing ob-
      stacles.                                           To construct a triple standard concertina
                                                    fence, first lay out and install all pickets from
         Of no advantage to the enemy.              left to right (as you face the enemy). Put the
P-4. TRIPLE STANDARD                                long pickets five paces apart, and the short (an-
     CONCERTINA FENCE                               chor) pickets two paces from the end of the long
                                                    pickets. The enemy and friendly picket rows
  Of the wire barriers a platoon or squad may       are offset and are placed 3 feet apart.

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     Now lay out all 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. This step is repeated for
every fourth picket thereafter.

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                                                       Install the front row concertina and hori-
                                                   zontal wire. Place the concertina over the

    Install the rear row of concertina and hori-       Install the top row concertina and join the
zontal wire.                                       rear horizontal wire.

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   The platoon or squad may also perform demo-     distance from the explosion by the
lition work. Basic to this is proper preparation   burn time of 30.5 centimeters (1 foot).
of a charge. There are two basic ways to deto-     This will give the number of centime-
nate an explosive charge: nonelectrically and      ters (feet) of fuse needed.
   Nonelectric. In the nonelectric way, troops
must follow these steps:
           (1) Clear the cap well of a block of
      TNT or push a hole about the size of a
      blasting cap (3 centimeters [1 1/3
      inches] deep and .65 centimeter [¼
      inch] in diameter) in a block of C4
      plastic explosive.

          (2) Cut and discard a 15-centime-
     ter (6-inch) length from the free end of
     the time blasting fuse to prevent a mis-
     fire caused by the exposed powder ab-
     sorbing moisture from the air.
          (3) Compute the burning time of a
     91.4-centimeter (3-foot) section of fuse
     to help determine how much fuse is
     needed to allow the person detonating
     the charge to reach a safe distance
     from the explosion. Divide this burn-
     ing time by 3 to find the burning time
     of 30.5 centimeters (1 foot). Now divide
     the time required to allow the person
     detonating the charge to reach a safe

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           (4) Inspect the nonelectric blast-         (6) After seating the cap, crimp it
       ing cap to insure it is clear of foreign   1/8 inch from the open end of the cap
       matter.                                    with a set of M2 cap crimpers. Point
                                                  the cap out and away from you when
                                                       (7) When using TNT, insert the
                                                  blasting cap into the cap well. When
                                                  using C4, place the cap into the hole
                                                  you made in the C4 and mold the C4
                                                  around the cap.

           (5) Gently slip the blasting cap
       over the fuse so that the flash charge
       in the cap is in contact with the end of
       the time fuse. DO NOT FORCE IT IN
       THE CAP.

                                                       (8) Insert the free end of the fuse
                                                  into an M60 fuse igniter and secure it
                                                  in place by tightening the fuse holder

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                                                  (10) If a fuse igniter is not avail-
                                             able, a match can be used to light the
                                             fuse. Split the end of the fuse and
                                             place the head of an unlighted match
                                             in the split (make sure the match head
                                             is touchng the powder train).

     (9) To fire, remove the safety pin,     Then light the inserted match head
hold the barrel in one hand, and pull        with another flaming match or by
on the pull ring with the other, taking      striking the inserted match head on a
up the slack before making the final         match box.
strong pull. If the fuse igniter misfires,
it is reset by pushing the plunger all
the way in and trying to fire as before.
If it still misfires, replace it.

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                    (11) If the fuse burns but the explo-
               sive charge does not go off, there is a
               MISFIRE. When this happens, wait 30
               minutes before attempting to clear it.
               If the misfire charge was not tamped
               (nothing packed around it), lay a
               primed charge of at least one block of
               C-4 or TNT beside it. If it was tamped,
              place at least two blocks of C-4 or TNT
              beside it. Do not move the misfire
              charge. The detonation of the new
              charge will detonate the misfire
           Electric. For the electric method, take the
         following steps:
                  (1) After locating a safe firing po-
             sition, lay out the firing wire from the
             charge to the tiring position. Before
             leaving the charge area, anchor the
             wire to something. ALWAYS KEEP

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    (2) Check the firing wire with a
galvanometers or circuit tester to make
sure the firing wire does not have a
short circuit or a break. Follow these
            STEP 1. Separate the firing
     wire conductors (bare ends of the
     wire) at both ends. Touch those at
     one end to the galvanometer/
     circuit tester posts. The needle on
     the galvanometers should not
     move, or the light on the circuit
     tester should not come on. If ei-
     ther the light comes on or the nee-
     dle moves, that firing wire should
     not be used because the firing
     wire has a short.

FM 7-7

                     STEP 2. Twist the conduc-
              tors together at one end of the fir-
              ing wire and touch those at the
              other end to the galvanometers or
              M51 blasting cap test set. This
              should cause a wide deflection of
              the galvanometers needle or the
              light to come on in the circuit
              tester. No movement of the needle
              in the galvanometers or light on
              the circuit tester indicates a
              break in the wire.

             (3) Check the blasting cap with a
         galvanometers or circuit tester to make
         sure it does not have a short. Remove
         the short circuit shunt. Touch one cap
         lead wire to one post and the other cap
         lead wire to the other post. When us-
         ing the galvanometers, the needle

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should make a wide deflection. If it             (5) Clear the cap well of a block of
does, the cap is good. If the needle fails   TNT or push a hole about the size of a
to move or only makes a slight deflec-       blasting cap in a block of C4 plastic
tion, the cap should be replaced.            explosive.

    (4) When using the circuit tester,           (6) Splice lead wires of cap to fir-
the light should come on when you            ing wires. (Western Union Pigtail.)
squeeze the handle. If it does not, the
cap should be replaced.

FM 7-7

           (7) Insert the cap into cap well of        (9) Fasten firing wires to the posts
       the TNT and secure with priming            of the blasting machine.
       adapter, or insert the cap into the hole
       you made in the C4 and mold the ex-
       plosive around the cap.

                                                       (10) Operate the blasting machine
                                                  to fire the charge.

           (8) Move to firing position and
       check the wire circuit with the gal-
       vanometers or circuit tester. (Same
       technique as described previously.)

                                                      (11) If the circuit checked out and
                                                  the blasting machine does not set the
                                                  charge off, there is a misfire.

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         (12) If an untamped charge mis-                       including the firing wire, for
     fires, investigate immediately. If the                    breaks and short circuits.
     charge is tamped, wait 30 minutes be-
     fore investigating. Follow these steps:                        (g) Make no attempt to re-
                                                               move the primer or the charge.
                 (a) Check the firing wire
           connection to the blasting ma-                             (h) Place a new primed
           chine to be sure that the contacts                  charge beside the misfire charge,
           are good.                                           if the fault has not been found.
                (b) Make two or three more                           (i) Disconnect the old blast-
           attempts to fire the charge.                        ing cap wires from the firing wire
                                                               and shunt the ends of the blasting
                (c) Try to fire again using                    cap wires.
          another blasting machine.
                                                                     (j) Finally, attach the new
                (d) Disconnect the firing                      blasting cap wires to the firing
          wire from the blasting machine                       circuit, wires before priming the
          and shunt the ends of the wire.                      charge with the blasting cap.
                (e) Move to the charge site                    Prime the charge with the cap
          to investigate.                                      and attempt to fire again. The
                                                               detonation will also dispose of
                 (f) Check the entire circuit,                 the misfire charge.

  Obstacles are used to halt or slow units, or to      Some obstacles may not restrict dismounted
cause them to move into an area which has been       elements but will restrict vehicular movement.
selected as a kill zone. If the enemy has selected   The platoon may have to clear obstacles to help
such an area, he will have prepared it so that he    vehicles go forward. Obstacles are normally cov-
can inflict great damage on any opponent mov-        ered by enemy direct and indirect fire to keep
ing into it. The enemy will exploit natural ob-      attacking troops from breaching them. The pla-
stacles such as defiles, rivers, thick woods,        toon may not be able to keep the enemy from
swamps, and cliffs, and reinforce them with          knowing that it is going to breach, but it should
man-made obstacles. There are seven basic            try to keep the enemy from knowing where and
kinds of reinforcing obstacles: minefield, abatis,   when it will try to breach.
log crib, log wall, tank ditch, crater, and wire.
Leaders must know the tactics and techniques           SUPPRESS, OBSCURE, SECURE, and RE-
used to overcome them and the problems which         DUCE (SOSR) are key actions in the steps to
they will present.                                   breach and clear an obstacle.

FM 7-7

         P-7. MINEFIELDS
           To maintain the momentum of an attack, the
         platoon must be prepared to breach minefield.
            These steps are followed to breach a mine-
                     STEP 1. SUPPRESS the enemy
                covering the obstacle. Artillery and
                mortar fire is used to suppress the en-
                emy. If indirect fire is not available,
                grenade launchers and machine gun
                fire are used.

                 STEP 2. Request smoke to OB-
             SCURE the obstacle area and conceal
             friendly troops.
                 STEP 3. SECURE the near side of
             the obstacle.

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    STEP 4. REDUCE the obstacle.          charge or bangalore torpedo. The only
Probe a footpath/lane and mark the        way to clear a minefield without
mines that are found. Lead elements       special equipment is to probe with
may be accompanied by engineers           pointed sticks. Bayonets should not be
equipped with specialized mine-           used; they can detonate antipersonnel
clearing equipment. The preferred         mines and other magnetic mines. One
way to clear a lane through a mine-       squad probes while the platoon (-)
field is to use a rocket-propelled line   overmatches.

FM 7-7

                The squad probing the footpath/lane
         through the minefield uses two probers one in
         front, clearing a lane wide enough to crawl
         through; and a second one, clearing 10 meters
         behind the first prober and slightly to one side so
         that their lanes overlap. The probers should not
         carry their weapons, field packs, load-carrying
         equipment, helmets, etc. Their equipment is car-
         ried by other squad members. Two other men
         crawl along behind to secure the probers, to carry
         additional supplies, or to take a prober’s job if one
         becomes a casualty. The probers should be rotated
         often to keep them from getting tired and/or care-
         less. The probe will be pushed in at an angle and
         when a hard object is felt, stop and mark.

             NOTE: If available, mine detectors
             should be used to clear the minefield.

                 The probers mark mine locations with
         sticks, engineer tape, cloth, or toilet tissue. They
         do not try to remove mines.

                                        FM 7-7

    STEP 5. Secure the far side. As
soon as the probers have cleared a
lane, the squad that cleared it moves
through the lane, and secures the far
side of the minefield.

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           STEP 6. When time permits, de-                  STEP 3. SECURE the far side of
       stroy the marked mines with explo-              the obstacle.
       sives (two 1-pound charges placed
       within a foot on each side of the mine).
           STEP 7. Mark the cleared lane.
           STEP 8. Move the unit through the

                                                           STEP 4. REDUCE the obstacle.
                                                       Mines and booby traps must first be
                                                       found and then neutralised by explod-
                                                       ing them with C4, or by pulling their
                                                       tripwires with grappling hooks and
                                                       long ropes. Use pioneer tools or explo-
                                                       sives to cut the trees from their
                                                       stumps. Tracked and wheeled vehicles
                                                       can be used to pull the logs out of the

   a. 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.
The trees are left attached to the stumps as high
as possible to make removal more difficult. This
obstacle may be reinforced with mines and booby
   b. These steps are followed to clear an abatis:
          STEP 1. SUPPRESS the enemy
      covering the obstacle.
          STEP 2. Request smoke to OB-
       SCURE the obstacle area and conceal
      friendly troops.

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                                                          These steps are followed to clear a
                                                        log crib:
                                                            STEP 1. SUPPRESS the enemy
                                                        covering the obstacle.
                                                            STEP 2. Request smoke to OB-
                                                        SCURE the obstacle area and conceal
                                                        friendly troops.
                                                            STEP 3. SECURE the far side of
                                                        the obstacle.
                                                            STEP 4. REDUCE the obstacle.
                                                        Use direct fire weapons (tank/com-
                                                        bat engineer vehicle), explosives, pio-
                                                        neer tools, and vehicles to reduce the
                                                          Log wall obstacles are very similar
P-9. LOG CRIB                                           to log cribs and require the same
                                                        clearing technique.
  A log crib is an obstacle constructed of logs,
earth, and rocks. The logs are used to make
cribs, which are filled with earth and rock.
These are used to block narrow roads and

                                                   P-10. TANK DITCHES
                                                     Tank ditches are usually in open terrain.
                                                   They are at least 4 meters (13 feet) wide and 1.8
                                                   meters (5 feet) deep. The enemy may put
                                                   barbed wire in them to keep tank crews or in-
                                                   fantry from dismounting and using the ditch for
                                                   shelter. He may prepare the approaches, sides,
                                                   and bottom of the ditch with antitank and an-

 FM 7-7

                                                 P-11. CRATERS
tipersonnel mines or chemicals to make breach-     The enemy uses explosives to create road
ing difficult.                                   craters. He will leave the loose spoil around the
                                                 sides of the crater to make it difficult for a tank
                                                 to back out.
                                                    A crater is cleared using the same steps as with
                                                 a tank ditch.

         These steps are followed to clear a
       tank ditch
           STEP 1. SUPPRESS the enemy
       covering the obstacle.
           STEP 2. Request smoke to OB-
       SCURE the obstacle area and conceal
       friendly troops.                          P-12. WIRE
           STEP 3. SECURE the far side of          The enemy uses wire obstacles to separate in-
       the obstacle.                             fantry from armor. He also uses them as road-
                                                 blocks against wheeled vehicles.
           STEP 4. REDUCE the obstacle.
       Use an armored combat earth mover,          These steps are used to breach a wire obstacle:
       tank with blade, or combat engineer                 STEP 1. SUPPRESS the enemy
       vehicle to push down the side of the           covering the obstacle.
       ditch. Explosives may also be used to
       blow down and slope the sides of the                STEP 2. Request smoke to OB-
       ditch.                                         SCURE the obstacle area and conceal
                                                      friendly troops.
                                                           STEP 3. Secure the near side of
                                                      the obstacle and clear a lane through
                                                      the wire. Use wire cutters, bangalore
                                                      torpedoes, or explosives to-remove the
                                                      wire. Watch out for antipersonnel
                                                      mines and booby traps. Mark any
                                                      mines and booby traps with engineer
                                                      tape, cloth, or anything recognizable.
                                                      One squad breaches while the platoon
                                                      (-) overmatches. Tank fire, combat en-

                                                                   FM 7-7

gineer vehicle fire, and massed indi-       STEP 5. Destroy the marked
rect and direct fire can help breach     mines with explosives or grapling
the wire.                                hooks (REDUCE).
    STEP 4. SECURE the far side. As         STEP 6. Mark cleared lane.
soon as the clearing squad has cleared
a lane, the squad moves through the          STEP 7. Move unit through the
lane and secures the far side.           obstacle.