052-195-3066 (SL3) - Direct Construction of Nonexplosive Obstacles

1.   Analyze mission requirements using the mission,
enemy, terrain, troops, time
available, and civilian considerations
(METT-TC) factors. 
Consider the following-

a.
Manpower available.

b.
Material available.

c.
Time available.

d.
Type of transportation.

e.
Site selection (take
advantage of existing obstacles).

f. 
Type of obstacle to be
constructed.

2.   Direct the construction of wire obstacles.

Note. When using U-shaped pickets to construct obstacles,
ensure the U faces the enemy.

a.
Direct the construction
of a double-apron 4- and 2-pace
fence. 
Ensure-

(1) 
The fence centerline is
laid.

(2) 
The long pickets are
spaced at 3-meter (4-pace)
intervals.

(3) 
The anchor pickets are
spaced at 1.5-meter (2-pace)
intervals each way from the
centerline and midway between the
long pickets.

(4) 
All 12 wires are
installed. 
Ensure work is done from
the enemy side to the friendly
side (figure 052-195-3066-1).

Figure 052-195-3066-1. 
Double-Apron Fence

Note.  Ensure the
soldier is not cut off between the
enemy and the fence.

(5) 
The wire is tied at the
beginning and end of each roll of
barbed wire, as a minimum.

(6) 
The wires are properly
secured and tight.

b.
Direct the construction
of a triple-standard concertina
fence.

(1) 
Ensure work is done
from the enemy side to the
friendly side.

(2) 
Direct the installation
of an anchor picket (short picket)
at each end of the front and back
row (2 paces).

(3) 
Ensure long pickets are
spaced at 3.8-meter (5-pace)
intervals (stagger the back row)
(figure 052-195-3066-2).

Figure 052-195-3066-2.
 Triple-Standard
Concertina Fence

Note. Install
the pickets in such a manner that the
lower notch of the long picket is 4
inches above the ground.

(4) 
Direct the installation
of concertina wire. 
Ensure-

(a)   A roll of
concertina is placed at the
third picket in the front row
and at every fourth picket
thereafter (figure 052-195-3066-3).

Figure 052-195-3066-3. 
Install Concertina and
Horizontal Wire

(b)  
The bottom row
(concertina wire) is secured
with the horizontal wire (barbed
wire) (figure 052-195-3066-4).

Figure 052-195-3066-4. 
Join Concertina Wire

(c)  
The back row
(friendly side) is begun once
the first team has cleared the
head of the fence.

(5) 
Direct the installation
of the remaining row of concertina
wire on top of the first two rows
and fasten it securely.

(6) 
Ensure the concertina
wire is properly tied and all
horizontal wire is properly
installed.

c.
Direct the construction
of a four-strand cattle fence.

(1) 
Ensure an anchor picket
(short picket) is installed at
each end of the fence.

(2) 
Ensure the long pickets
are installed 3 meters apart
(figure 052-195-3066-5).

Figure 052-195-3066-5. 
Four-Strand Cattle Fence

(3) 
Direct the installation
of the barbed wire. 
Ensure-

(a)  
The reel of barbed
wire is rolled out. 
Ensure that a row of
barbed wire is used per strand.

(b)  
The wire is tied from
the bottom strand and that it is
worked upward to the top strand.

(4) 
Ensure the wire is taut
and tied correctly.

d.
Direct the construction
of a knife rest.

(1) 
Ensure that a knife
rest is prepared 3 to 5 meters
long (figure 052-195-3066-6). 
Ensure-

Figure 052-195-3066-6. 
Knife Rest

(a)  
The end poles (1.2
meters in height and width) are
lashed to form two Xs.

(b)  
The center pole is
lashed to the two Xs.

(c)  
Barbed wire is used
to complete the knife rest.

(2) 
Ensure the knife rest
is secured to the ground.

e.
Direct the construction
of an 11-row obstacle out of
concertina wire.

(1) 
Ensure long pickets are
installed at 3.8-meter (5-pace)
intervals for 11 rows (figure 052-195-3066-7).

Figure 052-195-3066-7.
Eleven-Row Obstacle

(2) 
Direct the placement of
concertina wire over the long
pickets.

(3) 
Ensure the horizontal
wire (barbed wire) is anchored to
the anchor stakes 1.5 meters (2
paces) from each end of the
concertina rows.

(4) 
Ensure the horizontal
wire is secured over the
concertina wire.

(5) 
Ensure that a log 20
centimeters in diameter is placed
between the fifth and sixth row.

(6) 
Ensure the obstacle is
no less than 10 meters deep.

3.   Direct the construction of log obstacles.

Note. When constructing a log crib, use only logs with a
20-centimeter diameter minimum.

a.
Direct the construction
of a triangular log crib (figure 052-195-3066-8). 
Ensure-

Figure 052-195-3066-8. 
Triangular Log Crib

(1) 
The vertical postholes
are marked and dug 1.5 meters
deep. 
Ensure one corner of the
log crib is facing toward the
enemy and four 3-meter posts are
used per wall.

(2) 
The 12 horizontal logs
(four per wall) are cut to roadway
width.

(3) 
The vertical logs are
emplaced and tamped into place.

(4) 
The horizontal logs are
emplaced and posts are lashed
together with wire.

(5) 
The interior of the
crib is filled with earth material
taken from the enemy side of the
obstacle.

b.
Direct the construction
of a rectangular log crib (figure 052-195-3066-9
and table 052-195-3066-1). 
Ensure-

Figure 052-195-3066-9. 
Rectangular Log Crib

Table
052-195-3066-1.
Post Requirements
(Post Opposing/Offset Post Designs)

Road
Width (m)

1.8

2.1 to 3.6

3.9 to 5.4

5.8 to 7.3

8

12

16

20

2

3

4

5

4

6

8

10

Note. A
rectangular log crib can be emplaced
with the post opposing design or the
offset-post design.

(1) 
The vertical postholes
are dug and marked 1.5 meters
deep. 
Use table 052-195-3066-1
for post requirements.

(2) 
The horizontal logs
(four per wall) are cut to the
roadway width.

(3) 
The vertical logs are
emplaced 1.8 meters apart and
tamped into place.

(4) 
The horizontal logs are
emplaced and posts, logs, and
braces are lashed with wire.

(5) 
The interior of the
crib is filled with earth material
taken from the enemy side of the
obstacle.

c.
Direct the construction
of a log hurdle obstacle (figure 052-195-3066-10). 
Ensure-

Figure 052-195-3066-10. 
Log Hurdles

Note. Select a site where the log hurdles cannot be readily
bypassed. 
Hurdles are constructed on the
steepest part of a slope.

(1) 
Logs are cut 1.8 to 2.4
meters long.

(2) 
Three logs 25
centimeters in diameter or one log
45 centimeters in diameter are
used.

(3) 
Logs are staked firmly
in place. 
Ensure stakes are no more
than 1.5 meters apart.

(4) 
The log poles are
lashed to the stakes with wire.

(5) 
The securing stakes are
buried a minimum of 60 centimeters
in the ground with 60 centimeters
remaining above ground.

d.
Direct the construction
of a log post obstacle (figure 052-195-3066-11). 
Ensure-

Figure 052-195-3066-11. 
Log Post Obstacle

(1) 
A minimum of four rows
of posts are emplaced.

(2) 
Posts are cut in
varying lengths from 2 to 3
meters.

Note. The diameter of the timber is 40 centimeters minimum.

(3) 
Postholes are dug 1.5
meters underground.

(4) 
Posts are emplaced at
irregular distances of 1 to 2
meters and at irregular heights of
75- to 120-centimeters above
ground. 
Ensure posts are buried
vertically or at a slight angle
toward the enemy.

(5) 
The barbed wire is
attached to posts in an irregular
pattern.

4.   Direct the construction of tank ditch obstacles
(figure 052-195-3066-12).

Figure 052-195-3066-12. 
Tank Ditches

a.
Direct the construction
of a rectangular tank ditch
obstacle. 
Ensure-

(1) 
The T-push method is
used with a dozer/dozer,
dozer/loader, dozer/armored combat
earthmover (ACE), ACE/ACE, or
ACE/loader team configuration.

(2) 
The tandem method is
used with a scraper/scraper,
scraper/ACE, or a scraper/dozer
team configuration.

(3) 
The ditch is dug a
minimum of 1.5 meters deep and 3.3
meters wide.

(4) 
The berm is placed on
the friendly side of the ditch.

b.
Direct the construction a
triangular tank ditch obstacle. 
Ensure-

(1) 
The T-push method is
used with a dozer/dozer,
dozer/loader, dozer/ACE, ACE/ACE,
or ACE/loader team configuration.

(2) 
The ditch is dug a
minimum of 1.5 meters deep and 4
meters wide.

(3) 
The spoil is spread on
the enemy side of the ditch.

c.
Direct the construction a
sidehill-cut tank ditch obstacle. 
Ensure-

(1) 
The T-push method is
used with a dozer/dozer,
dozer/loader, dozer/ACE, ACE/ACE,
or ACE/loader team configuration.

(2) 
The one-dozer or ACE
method is used.

(3) 
The tank ditch is cut a
minimum of 1.5 meters deep and 4.5
to 6 meters wide.

(4) 
The spoil is spread on
the enemy side of the ditch.

5.   Direct the construction of barrier obstacles.

a.
Ensure barrier materials
are obtained. 
Barrier materials include-

(1) 
Steel hedgehogs and
tetrahedrons (figure 052-195-3066-13).

Figure 052-195-3066-13. 
Steel Hedgehog and Tetrahedron

(2)  Concrete cubes and
tetrahedrons (figure 052-195-3066-14).

Figure 052-195-3066-14. 
Concrete Cubes and
Tetrahedron 

(3)  Jersey barriers
(figure 052-195-3066-15).

Figure 052-195-3066-15. 
Jersey Barrier

b.
Ensure barrier materials
(figure 052-195-3066-16)
are emplaced.

Figure 052-195-3066-16. 
Concrete Obstacle Placement

Note. The distance between barriers will vary depending on the
type of traffic expected (cars,
trucks, or semitrailers).

1.   Analyzed mission requirements using the METT-TC
factors.

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2.   Directed the construction of wire obstacles.

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3.   Directed the construction of log obstacles.

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4.   Directed the construction of tank ditch obstacles.

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5.   Directed the construction of barrier obstacles.

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FM
5-34

FM
5-102