TM 9-1375-213-12
e. Safe Distance From Demolitions.
Table 1-6. Minimum Safe Distance for Personnel
in the Open - Continued
(1) Blast effect. Generally, the greater danger to
Approximate
personnel is the missiles thrown by the explosion. Blast
safe distance
effect (the increase in air pressure) is a hazard even
Pounds
of explosive
meter
feet
though special protective features are used at detonation
90
449
1,330
or demolition sites to eliminate or confine missiles and
100
465
1,390
provide for detonation of charges close to personnel.
125
500
1,500
Personnel provided the minimum protection prescribed
150
534
1,590
in (3) below will not generally be endangered by blast ef-
175
560
1,680
fects.
200
585
1,750
225
609
1,820
250
630
1,890
275
651
1,950
missiles great distances. How far an explosion-propelled
300
670
2,000
missile will travel in air depends primarily upon relations
325
688
2,070
between weight, shape, density, initial angle of projec-
350
705
2,100
375
722
2,160
tion, and initial speed. The missile hazard from steel-cut-
400
737
2,210
ting charges extends a greater distance under normal
425 and over
750
2,250
conditions than that from cratering, quarrying, or surface
charges of bare explosives.
1-16. Care and Handling
(3) Safe distances. The following criteria give the
a. Explosive demolition materials must be han-
missile hazard distances at which personnel in the open
dled with appropriate care at all times. The explosive el-
are relatively safe from missiles created by bare charges
ements in primers, blasting caps, and fuzes are
particularly sensitive to shock and high temperatures.
placed in or on the ground, regardless of type or condi-
tion of the soil (AR 385-63). For charges ranging from
b. Personnel should be trained to handle all demolition
27 to 425 pounds, the distance in meters at which person-
items and components, including practice and training
nel in the open are relatively safe from missiles can be
items, as potentially dangerous, even though the items
calculated as follows:
have been designated INERT. The same basic safety
rules should be followed when using inert training or lec-
D = 100
3
ture aids as those when loaded items are being used.
P
where
Striking, dropping, or handling in other than the manner
P = Pounds of Explosive
prescribed for explosive loaded (live) items should not
D = Safe Distance in Meters
be permitted. In order to make inert items readily identi-
*D equals 100 times the cube root of the weight of explo-
fiable, sometimes several holes are drilled or cut in them
sives.
where practicable. In addition, they are stamped and/or
stenciled INERT if they have no explosive filler and
Safe distances calculated for selected charge weights are
PRACTICE if they contain an inert or low-explosive fill-
given in table 1-6.
er. Inert and practice demolition items are painted light
blue with white lettering. Practice demolition items with
Table 1-6. Minimum Safe Distance for Personnel
a low-explosive filler have a brown band. Older inert
in the Open
items are painted black with white lettering.
Approximate
c. In order to keep explosive demolition materials in a
safe distance
Pounds
serviceable condition and ready for immediate issue and
of explosive
meter
feet
use, the general rules in (1) through (5) below apply.
1 to 27
300
900
30
311
930
(1) Store explosive demolition materials in the
35
327
980
original containers in a dry, well-ventilated place pro-
40
342
1,020
45
356
1,070
tected from the direct rays of the sun and other sources of
50
369
1,100
excessive heat. Keep sensitive initiators such as primers,
60
392
1,170
blasting caps, fuses, and igniters separate from other ex-
70
413
1,240
plosives.
80
431
1,290
1-40 Change 19
