Editing Inner German border (section)

===Outer fence, walls and minefields===

The outer fences were constructed in a number of phases, starting with the initial fortification of the border from May 1952. The first-generation fence was a crudely constructed single barbed-wire fence (''Stacheldrahtzaun'') which stood between {{convert|1.2|and|2.5|m|ft}} high and was built very close to the actual border line.<ref>[[#Rottman|Rottman (2008)]], p. 16.</ref> This was replaced in the late 1950s with parallel rows of more strongly constructed barbed-wire fences, sometimes with [[concertina wire]] placed between the fences as an additional obstacle.<ref>[[#Rottman|Rottman (2008)]], p. 18.</ref>

<div class="center">{{Gallery
|title=East German border fences and walls
|width=200
|height=160
|Inner german border 1st generation.jpg|Reconstruction of the "first-generation" fence as erected in 1952, with control strip in the foreground
|East German border 1962.jpg|The "second-generation" fences in 1962, with derelict barbed wire in the foreground, a control strip, two rows of barbed wire further back and a watchtower at the rear
|Inner german border fence and pole.jpg|The third-generation fence, constructed from several overlapping horizontal tiers of expanded steel mesh fencing. A border marker pole is in the foreground.
}}</div>

[[File:Sm-70 schlagsdorf.jpg|thumb|250px|right|alt=Horn-shaped device mounted on the side of a metal fence, with trigger wires attached to it and running parallel to the fence into the foreground and background.|[[SM-70]] tripwire-activated directional anti-personnel mine mounted on the fence. The cone contained an explosive charge which fired shrapnel fragments when activated.]]
A "third-generation" fence, much more solidly constructed, was installed in an ongoing programme of improvements from the late 1960s to the 1980s. The fence line was moved back to create an outer strip between the fence and the actual border. The barbed-wire fences were replaced with a barrier that was usually 3.2–4.0 metres (10–13&nbsp;ft) high. It was constructed with [[expanded metal]] mesh (''Metallgitterzaun'') panels. The openings in the mesh were generally too small to provide finger-holds and were very sharp. The panels could not easily be pulled down, as they overlapped, and they could not be cut through with a bolt- or wire-cutter. Nor could they be tunnelled under easily, as the bottom segment of the fences was partially buried in the ground. In a number of places, more lightly constructed fences (''Lichtsperren'') consisting of mesh and barbed wire lined the border.<ref name="Rottman-25">[[#Rottman|Rottman (2008)]], p. 25.</ref> The fences were not continuous but could be crossed at a number of places. Gates were installed to enable guards to patrol up to the line and to give engineers access for maintenance on the outward-facing side of the barrier.<ref name="Rottman-25" />

In some places, villages adjoining the border were fenced with wooden board fences (''Holzlattenzaun'') or concrete barrier walls (''Betonsperrmauern'') standing around {{convert|3|–|4|m|ft}} high. Windows in buildings adjoining the border were bricked or boarded up, and buildings deemed too close to the border were pulled down. The barrier walls stood along only a small percentage of the border{{snd}}{{convert|29.1|km|mi}} of the total length by 1989.<ref name="Rottman-17" />

Anti-personnel mines were installed along approximately half of the border's length starting in 1966; by the 1980s, some 1.3&nbsp;million mines of various Soviet-made types had been laid.<ref>[[#Rottman|Rottman (2008)]], pp. 18–19.</ref> In addition, from 1970 the outer fence was booby-trapped with around 60,000 [[SM-70]] (''Splittermine-70'') directional anti-personnel mines. They were activated by tripwires connected to the firing mechanism. This detonated a horn-shaped charge filled with [[Fragmentation (weaponry)|shrapnel]] that was sprayed in one direction along the line of the fence. The device was potentially lethal to a range of around {{convert|20|m|ft}}<!-- (this distance conflicts with the lethal range indicated in the sm-70 article), it was about 20 m - maybe a typo-->. The mines were eventually removed by the end of 1984 in the face of international condemnation of the East German government.<ref name="Rottman-21">[[#Rottman|Rottman (2008)]], p. 21.</ref>