Fortifications of the inner German border

The outer fences and walls were the most familiar and visible aspect of the system for Western visitors to the border zone, but they were merely the final obstacle for a would-be escapee from East Germany.

Travelling notionally from east to west,[1] an escapee would first reach the edge of the restricted zone (Sperrzone), a closely controlled strip of land 5 kilometres (3.1 mi) wide, running parallel with the border.

The signal fence (Signalzaun), around 500 to 1,000 metres (1,600 to 3,300 ft) from the actual border, was lined with low-voltage electrified barbed wire which activated alarms when touched or cut.

Guard towers, bunkers and dog runs were positioned at frequent intervals to keep a round-the-clock watch over the strip.

Tripwire-activated flare launchers were situated at various points to help the border guards pinpoint the location of an escape attempt.

Finally, the escapee had to cross whatever natural obstacles were on the western side of the border fence as well as traversing a strip of cleared ground that was up to 500 meters (1640 ft) wide.

While crossing this outer strip, the escapee would appear in clear view and shooting range of the border guards before reaching the safety of West German territory.

The Sperrzone, a 5 kilometres (3.1 mi) wide area to which access was heavily restricted, was the rear segment of the border defences.

Although the land continued to be farmed where possible, many of the inhabitants were expelled on the grounds of political unreliability or simply because they lived inconveniently close to the border line.

[2] Those who remained behind were required to be completely loyal to the regime and support the border guards, helping them by watching for strangers and unfamiliar vehicles.

Even so, they had little freedom of movement; special permits were required to enter the zone and farmers worked under close supervision.

Initially they were simple wooden huts mounted on legs between 4 and 12 metres (13 and 39 ft) high, usually constructed from locally sourced timber.

They were connected to an electricity supply and telephone line and were equipped with a powerful 1,000-watt searchlight (Suchscheinwerfer) on the roof that could be directed at targets in any position around the watchtower.

[7] When the "modern frontier" was constructed in the late 1960s, an all-weather patrol road (Kolonnenweg, literally "convoy path") was laid down to enable the guards to travel rapidly to any point along the border fence.

It was almost impossible to cross the strip without leaving footprints, enabling the border guards to identify otherwise undetected escape attempts.

One of those involved, a resident of the Thuringian village of Kella, later recalled: The tree stumps were blown up, and there wasn't enough soil left over so they had to carry dirt up [the hill] in baskets.

These anti-vehicle devices were constructed from three or four pairs of 1.5-metre-long (4.9 ft) rails welded together to form a steel obstacle weighing over 500 kilograms (1,100 lb) – heavy enough to stop a motor vehicle from pushing them aside.

These lined 829 kilometres (515 mi) of the border and were absent only where natural obstacles such as streams, rivers, gullies or thick forests made such barriers unnecessary.

In a few places, gaps were purposefully left with lowered gate poles in front of them and anti-vehicle Czech hedgehog barricades behind.

In a number of places, more lightly constructed fences (Lichtsperren), consisting of mesh and barbed wire, lined the border.

They were chained and locked with heavy-duty padlocks, and a sharp saw-toothed steel strip was bolted to the top of the gates to prevent them from being climbed.

The mines were a hazard to civilians on both sides of the border; they were frequently set off by animals such as deer and could be washed out of position by rain or floods.

The device consisted of a horizontally oriented cone filled with 110 grams (3.9 oz) of TNT explosive into which was embedded approximately 80 small sharp-edged steel cubes.

On one occasion, when a deer fell victim to an SM-70, an observer noted that "an approximately 5 meter [20'] area appeared as if it had been worked over by a rake.

The later "modern frontier", by contrast, incorporated a wide strip of cleared land on the western side in front of the border fence.

Although often described by Western sources as a "no-man's land", it was in fact wholly East German territory; trespassers could be arrested or shot.

It was marked by granite border stones (Grenzsteine), 20 centimetres (7.9 in) square with a + carved on the top and the letters "DDR" on the east-facing edge.

In August 1967, East Germany erected 2,622 distinctive border markers or "barber's poles" (Grenzsäule or Grenzpfähle), each located about 500 feet (150 m) apart.

A metal East German coat of arms, the Staatsemblem, was fixed to the side of the column that faced West Germany.

The column terminated in a metal spike to stop birds using the border markers as a perch and thereby prevent them from defecating on the coat of arms.