TM 9-1375-213-12
assurance of detonation, expecially with less secsitice
(1) Keep cap wells, coupling bases, and nonelec-
explosives. A secondary capwell can be foremd in softer
tric blasting caps free of dirt and sand. Such contamina-
explosives (C4 or dynamite) using the pointed lef of a
tion can cause misfires.
cap crimper. For TNT tetrtol blocks. a second cap could
be taped to the side of the block with a piece of FLEX-X
(2) To prevent mechanical malfunctions, protect
(M118 or M186) explosive which is equipped with an
firing devices from blowing dust and sand.
adhesive tape on one surface, this giving a ready-made
(3) All blasting machines should be protected
graph 2-19 to assure
that you
use enough FLEX-X and
from exposure to blowing dust and sand to avoid fetting
properly position the cap.
it into the gears. Even the well-sealed M32 and M34
should he given special care to avoid such exposure.
d. Alternately, at least three wraps of detonating cord
Wrapping and sealing the machines in a plastic bag or
can he used as the priming charge; the detonating cord it-
tarpaulin is advised whenever such exposure may be en-
self initiated in a standard manner.
countered, whether in storage or in transport; even dur-
ing transport to an operation.
e. Because they must be initiated from a single point
for proper effect, shaped charges cannot be directly dual
(4) Though both the galvanometer and test set are
primed. An almost equivalent assurance of initiation can
quite will sealed against dust. dirt, and sand, exposure to
be obtained by priming the shaped charge with a non-
such blowing elements should be avoided. If a test set is
electric blasting cap on a piece of detonating cord and
exposed to blowing sand or blowing dirt or dust -espe-
then affixing dual firing systems to the detonating cord.
cially blowing sand - blow out the areas around the han-
This method is also applicable to standard block charges.
dle pivots by mouth or with compressed air before
attempting to use the instrument.
2-32. Static Discharge in M60 and M81 Igniters
2-31. Dual Priming Methods
When alighting from aircraft, especially helicopters, per-
sonnel will often experience an electrical shock due to
the static electricity build-up in the aircraft. Under some
erations, dual priming is advised. Normally it is em-
conditions, the static discharge may travel through a
ployed in multicharge operations to assure that all the
rucksack in which an M60 or M81 is being stored and
charges fire. In extreme circumstances, it may be neces-
initiate the igniter's primer. The small charge in the
sary to dual prime even a single charge.
primer may fire and crack or blow apart the igniter's
plastic body, but it is unlikely to do any other harm.
h. Then this is the case, it is essential that all steps are
Keep M60 and M81 igniters in their harrier hags when
taken to assure that both primers on the blasting caps will
being personnel-transported to protect them from such
be fully capable of initiating the charge.
static discharge.
c. Merely taping or tying a second blasting cap to the
side of a charge is not advised since this does not provide
2-50
Change 18
PIN: 026679-018
6 US GOVERNMENT PRINTING OFFICE: 1996-746-043/40703