A study of the enemy employment of minefields in North Africa has shown
their various tactical uses. One of the principal of these uses is the protection
of the entire front of a major defensive position. This type of minefield can be
designated the "Large Protective Minefield," and its construction follows a more
or less fixed procedure. This procedure results in protection being built up
gradually but concurrently along the entire front. The first steps are such that
they give the maximum initial protection and at the same time serve as an
important part of the final installation. The actual construction can be conveniently
divided into three phases, which are described in the following paragraphs.
a. Phase One
A single continuous belt of mines is laid along the entire front. This belt
is generally marked and protected on both sides by concertina or barbed wire;
the spacing between the rows of wire is usually about 200 yards, but may be as
much as 800. While this initial belt is being laid, the incomplete points in the line
are held or supported by armor.
As soon as the initial belt and marking wire have been laid, thickening of
the field is begun by placing an additional belt of mines in front of the forward
wire marking the initial belt. The front edge of this second belt is generally not
marked during this phase of preparation. From the start, the area mined during
this phase is covered by short range, small-arms and antitank fire, while
listening and machine-gun posts are interspersed throughout the field.
While this initial phase of mine-laying is under way, the construction of
the battalion defense areas is in progress behind this belt of mines. These
defense areas are being spaced from 1 to 2 miles from center to center in mutual
support as shown on the accompanying sketch, As these defense areas and the
mine belts near completion, the armor is moved to the rear for a counterattack
b. Phase Two
One step in this phase is the marking and protecting by concertina or
barbed wire of the second belt of mines laid in the first phase, and the thickening
of the field by placing an irregular belt of mines in front of the new forward wire.
This forward belt is complicated by numerous unmarked tactical spurs and small
scattered minefields farther out, together with scattered wire obstacles and false
gaps. This forward zone is likely to be sown with all forms of antipersonnel devices
and automatic trip wires. It may extend as much as 800 yards in front of
the original front wire.
A second step is to lay a belt of mines to afford protection to the second
line of defense areas, which is being constructed during this phase. The
minefields are from 100 to 200 yards deep and are sometimes not as clearly marked
as the front fields. The defense areas are echeloned back from the original
defensive line, and tactically sited to support it. The second line of defense areas
form triangles, on 1 to 2 mile centers, with the forward defense areas.
Another step in this phase is to interconnect the original mine belt and
the rear belt described in the proceeding paragraph; these interconnections serve,
by hindering lateral movement, to canalize and disorganize any enemy penetration
through the frontline belt. This, in effect, serves to compartment every local
success of the enemy. In this connection it has been noted that although the layout
and marking of the minefields may appear ill-defined or haphazard to the ground
observer, they are generally very distinct on air photographs.
c. Phase Three
A third line of minefields, generally well marked, is then laid to give additional
protection to the front and flanks of the second line of defense areas.
This new line of minefields may at this time be connected with the second belt of
mines discussed in phase two; it serves to further compartment the field and to
disrupt lateral movement by the enemy in event of local enemy successes. The
third line of minefields Is usually about 200 yards deep.
During this phase, further thickening of the previously laid belts may take
place by the addition of booby traps, antipersonnel mines, and small minefields
and scattered mines, usually unmarked. In rear areas, tactical and protective
fields may also be laid at this stage; these are usually visible on aerial photographs
Troops holding front main defense areas are likely to be thinned out gradually at this
stage, and a third line of defense areas put under construction in the rear area.