The following observations and sketches on passive Soviet antitank defenses were
made by U.S. Military Attaches after a visit to the Gzhatsk-Vyazma front
during the latter part of June 1942.
* * *
On every possible defensive position the Soviets have constructed barriers, barbed-wire
barricades, escarpments, tank traps, and tri-railed cleats. All of these obstacles are
supported by fortified dugouts and pillboxes of various sizes, so placed as to cover the
approaches of the enemy units, which would be canalized by the barricades.
The main antitank escarpment extends perpendicularly from the road, either 200 to
300 yards out, or to a secure flank such as a woods or swamp. The ditch usually follows
the contour of the terrain and is normally located on a forward slope so that the rear
wall rises far above the front wall. The rear (Soviet) bank of a stream affords an
excellent site for an escarpment. Escarpments are dug as nearly level as possible so
as to retain water from the snows, rains, or swamps. Dirt excavated from the ditch is
thrown to the rear ramp. The escarpment usually is dug about 10 feet deep and
about 20 feet wide.
In front of the escarpment is usually placed a barbed-wire barricade of the same length
and about 3 feet high and 10 feet wide. This wire is designed principally to
keep enemy infantry from utilizing the escarpment as a trench.
The Soviets construct single or multiple rows of tri-railed or 6-inch steel I beams,
or 3- to 4-inch pipes welded or bolted together and, depending on the terrain, place
them in front or in the rear of escarpments, or sometimes in isolated positions. The
advantage of this type of barricade is that it can be prefabricated in the rear and
brought up and merely dumped into position.
Rows of posts in checkerboard fashion, 3 feet high and 10 feet wide, strengthen the
system. In some areas entire groves of trees were cut down and cleared away, leaving
only 3-foot stumps.
Another type of antitank obstacle (shown in sketch below) consisted of parallel ditches
about 3 feet deep, 3 feet wide, and 30 feet long, and so spaced as to deny tanks sufficient
clearance. Groups of such ditches would be placed at varying angles to neighboring
groups, their purpose being to cause tanks to become hung on the edges.
Antitank obstacles and ditches are constructed under the supervision of engineers, but
troops of the communication zone and civilians are used to do the digging. There is no
special equipment for digging, and it is all by hand.