With the German Army increasingly on the defensive, it is pertinent for us
to know as much as possible about the enemy's employment of barbed-wire
obstacles in continental Europe. A classic asset of the defense, barbed
wire naturally plays an important part in the coastal and inland defense
systems that the Germans are hurrying to complete in the occupied countries. The
following aspects of German wire technique have recently been observed in
France, The Netherlands, and Belgium.
On beaches, barbed wire is usually erected in straight lines, parallel to
the shore and in front of fortified areas. Between these fortified areas, the
lines of wire jut out at right angles toward the sea.
Around emplacements and fortified areas, the depth of wire obstacles
varies, depending on the nature of the terrain and the importance that
the Germans attach to the site. In some places the depth may range from
30 to 60 yards; in other positions, it may range from 70 to 130 yards, or
may be as much as 200 yards. As a rule, the distance between the outside
edge of the wire and the nearest pillbox or other firing position is
at least 30 yards.
In gullies and in the crevices of cliffs, if ascent is considered at all
possible, the Germans install dense wire entanglements. In front of
these, the enemy sometimes places small-mesh wire, evidently for the
purpose of slowing any advance in which Bangalore torpedoes might be
used. Halfway up the gullies and crevices, the entanglements usually
begin to thin out. Sometimes they continue as single fences running
along the tops of the cliffs, near the margins.
In conjunction with road blocks, a wire fence or entanglement is often
erected on each side of the road, and the gap between is closed by movable
gates of various types. In many places concrete walls and other more
substantial types of barriers are replacing wire entanglements as road
blocks; however, wire is nearly always used on top of these wall barriers, for
additional protection. Wall barriers and concrete emplacements are likely to
have iron staples in them so that wire entanglements can be firmly secured.
Often the Germans use wire to fence off all sides of a minefield. Such fences
consist of a single row of pickets connected by five or six strands of
wire. Also, a thin belt of wire is commonly found outside antitank ditches.
The Germans are now making extensive use of a new type of barbed
wire. This new type is made of a non-corrosive metal, and is thicker
than ordinary wire. It is square in cross-section, rather than round. The
wire, which is twisted, has 3/4-inch barbs, 4 inches apart.
2. SPECIFIC TYPES
The following are specific types of wire obstacles that the Germans are
erecting in France, Belgium, and The Netherlands. Several of these types
were encountered in North Africa, and any or all must be expected wherever
the Germans have had an opportunity to prepare defenses. The dimensions given
here an approximate.
a. Knife Rests
X-shaped metal knife rests, or "chevaux-de-frise," strung with wire, have
been observed above the high water mark on beaches. Sometimes this type of
obstacle consists of four trestles connected by a crossbar, and has the
|Span of trestle legs||
|Distance between trestles||
||4 to 5 feet|
|Length of four-trestle unit||
||16 to 20 feet|
b. Apron Fences
These may be single or double aprons. They are supported by screw
pickets or by angle irons embedded in concrete to a depth of about
18 inches. Often a coil of concertina wire is placed under a double
apron fence, and sometimes another coil is placed along the top. The
dimensions of a typical apron fence are as follows:
||4 to 5 feet|
|Height (with coil on top)||
||7 to 8 feet|
||Up to 30 feet|
c. Vertical Fences
Ordinary vertical fences are always installed in two or three lines, from
4 to 8 feet apart. Each fence has five or six strands of wire, and is 4
to 6 feet high. The wire is supported by wooden posts, angle irons, or
screw pickets. The spaces between fences are frequently filled with wire
entanglements and mines.
d. Concertina Fences
Single, double, or triple coils of concertina, supported by angle irons
or screw pickets, are often used as fences. Triple coils are frequently
affixed to the protecting rails of the beach promenades which are so
common in the coastal towns of western Europe.
e. Trip Fences
Trip wires are often laid in front of important beach obstacles. These
wires will usually be found between the high-water mark and the first
barbed-wire entanglement. They are also used in the minefields in front
of main defensive positions and main obstacles. Trip fences have the
||4 to 6 in|
|Length of each diagonal or diamond-shaped section||
||4 to 6 ft|
|Width of whole obstacle||
||12 to 20 ft|
f. Alarm Wires
The Germans often place some form of alarm device in barbed-wire
fences. Grenades and small explosive charges are common. Insulated
live wire, which rings a bell as soon as it is cut, has also been
encountered. It must be remembered that almost any kind of improvised
alarm device will serve the defenders' purpose, provided that it
produces enough noise to warn effectively.
g. Electrified Wire
Electrified barbed wire, attached to pickets by means of insulators, has
been reported. This type of obstacle is not used on a very large scale,
h. Combined Fences
A typical combined fence consists of the following units, in sequence: a
trip wire, a trestle fence or knife rest, and an apron fence. The apron
fence is likely to be from 10 to 20 yards behind the trestle fence or
knife rest, and the total depth of the whole combination may be from
30 to 60 yards. On the sea fronts of towns, the Germans usually erect
an apron or knife-rest fence on the beach, and a concertina or apron
fence on top of the sea (retaining) wall or beach promenade.
3. STANDARD TECHNIQUE
The Intelligence Bulletin distinguishes between German technique
which has actually been observed, and that which is prescribed in German
training documents. Some notes regarding the latter are given below.
a. Obstacle in Depth
This type of obstacle is constructed to a depth of about 33 feet. It
consists of ordinary wire fences erected at intervals of about 5 feet
and connected with crisscrossed plain wire (see fig. 1). The spaces between
the fences are filled with barbed wire in spirals. These spirals are
fastened to each other and to the pickets of the crisscrossed wire. When
obstacles of this type are erected in woods, trees are often used to
support the wire.
|Figure 1.—German Obstacle in Depth.|
Wire obstacles in depth are usually installed in places where they will
be screened as far as possible against observation by opposing forces. Woods,
hollows, sunken roads, and heavily overgrown reverse slopes are sites especially
favored by the enemy.
b. Wire-netting Fences
The Germans use wire netting as an emergency obstacle against
infantry. They believe it to be most effective in woods and on
the near side of hedges, and recommend that it be secured to the
ground with wire and pickets. An obstacle of this type illustrated
in a German training manual is 6 feet 6 inches high.
c. Trip-wire Obstacles
German training doctrine prescribes that these obstacles be at least
30 feet in depth. Irregular rows of wooden pickets, 2 feet high and
3 inches in diameter, are driven into the ground, and barbed or plain
wire is stretched between pickets, at a height of 4 feet 8 inches. The
interval between pickets in a row is 10 to 13 feet, and the interval
between rows is 7 to 10 feet. Freshly cut pickets are painted to blend
with the surroundings.
Trip-wire obstacles can be concealed effectively in gullies and on
ground covered by low growth, especially if rusted wire is used. Mines
and booby traps, equipped with pull-igniters, may be combined with