TM 9-1375-213-12
(2) If misfired charge is not stemmed, lay a primed
1-pound charge at side of misfired charge without mov-
ing or disturbing it, and fire.
WARNING
(3) If fired charge has not more than a foot of
stemming, attempt to explode it by detonating a new 2-
WORKING ON OR NEAR A MISFIRE
pound charge placed on top.
IS THE MOST HAZARDOUS OF ALL
BLASTING OPERATIONS. A MIS-
(4) If the misfired charge is located in a stemmed
FIRE CANNOT IMMEDIATELY BE
borehole, or if placement of stemmed charge makes
DISTINGUISHED FROM A DELAY
method (3) above, impractical, follow either procedure
FUNCTION. DO NOT HANDLE SUS-
listed below.
PECTED MISFIRES UNTIL AFTER
REQUIRED WAITING PERIOD HAS
ELAPSED AND OTHER SAFETY
PRECAUTIONS HAVE BEEN AC-
WARNING
COMPLISHED.
DIGGING INTO CHARGE MAY
INITIATE CHARGE. CHECK ON
a. Prevention. A misfire should be extremely rare if
DEPTH AND DIRECTION OF
these procedures are followed closely:
BOREHOLE DURING DIGGING
TO MINIMIZE DANGER OF
(1) Prepare and place all components of priming
STRIKING CHARGE OR PLAC-
ING A NEW CHARGE TOO FAR
systems, as required, following step-by-step procedures.
AWAY TO INDUCE DETONA-
TION.
(2) Load charges carefully.
CAUTION
(a) Procedure No. 1.
TO AVOID DAMAGING ITEM, DO NOT
1. Carefully remove stemming by nonmetal-
USE ANY MATERIAL LARGER THAN
lic or nonsparking tools or, if available, by a stream of
3 INCHES IN DIAMETER WHEN STEM-
compressed air or water.
MING AN UNDERGROUND CHARGE.
2. Dig until charge is within one foot of be-
ing uncovered.
(3) Perform any stemming operation with care to
avoid damage to charges.
3. Insert a new, primed 2-pound charge on
top of misfired charge.
(4) Fire charge according to proper technique.
4. Detonate a new 2-pound charge. Whenev-
(5) Do not use blasting caps underground; use
er possible, detonating cord should be used to prime ei-
detonating cord.
ther underground or above ground charges (paras 2-10
through 2-12).
b. Clearing of Nonelectric Non-shock Tube Misfires.
Occasionally, a nonelectric misfire will occur. Investiga-
(b) Procedure No. 2.
tion and correction should be undertaken only by the per-
son who placed the charge. For a charge primed with a
1. Carefully dig a new hole to within one
nonelectric cap and time blasting fuse, the procedure is as
foot and to the same depth as old hole.
follows:
2.
Place a new, primed 2-pound charge in
(1) Delay investigation of misfire at least 30 min-
new hole.
utes after expected time of detonation. This should be
ample time for any delayed explosion to take place be-
3. Detonate new, primed 2-pound charge.
cause of a defective power train in the fuse or burning
Follow instructions listed in (a) 4 above.
charge. Under certain combat conditions, however, im-
mediate investigation may be necessary.
Change 19
