SM-70
Encyclopedia
The SM-70 was an East German directional antipersonnel mine developed specifically to combat "Republikflucht
Republikflucht
"Republikflucht" and "Republikflüchtling" were the terms used by authorities in the German Democratic Republic to describe the process of and the person leaving the GDR for a life in West Germany or any other Western country .The term...

" (defection
Defection
In politics, a defector is a person who gives up allegiance to one state or political entity in exchange for allegiance to another. More broadly, it involves abandoning a person, cause or doctrine to whom or to which one is bound by some tie, as of allegiance or duty.This term is also applied,...

) across the Inner German Border (Grenze) into West Germany
West Germany
West Germany is the common English, but not official, name for the Federal Republic of Germany or FRG in the period between its creation in May 1949 to German reunification on 3 October 1990....

.

Design

First fielded in 1970, the mines were cone-shaped, tripwire
Tripwire
A tripwire is a passive triggering mechanism. Typically, a wire or cord is attached to some device for detecting or reacting to physical movement...

 activated, and mounted to concrete posts along the line of climb-resistant prefabricated steel mesh fence. In some cases, they were mounted directly to the fence itself. They were aimed parallel with the fence line, and intended to kill or incapacitate anyone attempting to climb or cut through the fence.

Service

Beginning in late 1970, approximately 60,000 SM-70s were installed on sp=us 440 of particularly escape-prone rural sections of the East German border. Installation of the mines cost 100,000 East German mark
East German mark
The East German mark commonly called the eastern mark , in East Germany only Mark, was the currency of the German Democratic Republic . Its ISO 4217 currency code was DDM...

s per kilometer, for a total cost of over 44 million marks. The mines were not used on the Berlin Wall
Berlin Wall
The Berlin Wall was a barrier constructed by the German Democratic Republic starting on 13 August 1961, that completely cut off West Berlin from surrounding East Germany and from East Berlin...

. Initial plans called for the SM-70 to completely replace the buried PMN anti-personnel mines
PMN mine
The PMN series of blast anti-personnel mines were designed and manufactured in Russia. They are one of the most widely used and commonly found devices during demining operations.-PMN-1:...

 along the border, but initial problems with the electrical firing devices after exposure to the elements actually resulted in more PMN mines being emplaced as a stopgap measure. When fired, the SM-70 produced a cone of fire lethal within sp=us 25. One East German described finding a deer shredded by an SM-70, noting that a 5m area "appeared as if it had been worked over by a rake."

Although referred to within the Border Guards by the National People's Army
National People's Army
The National People’s Army were the armed forces of the German Democratic Republic .The NVA was established in 1956 and disestablished in 1990. There were frequent reports of East German advisors with Communist African countries during the Cold War...

 designation G-501, for propaganda
Propaganda
Propaganda is a form of communication that is aimed at influencing the attitude of a community toward some cause or position so as to benefit oneself or one's group....

 purposes the mines were referred to as "Automatic Firing Devices" (German
German language
German is a West Germanic language, related to and classified alongside English and Dutch. With an estimated 90 – 98 million native speakers, German is one of the world's major languages and is the most widely-spoken first language in the European Union....

: "Selbstschussanlage") in public documents. The cryptic description led to the public perception that the mine was a type of automated
Automation
Automation is the use of control systems and information technologies to reduce the need for human work in the production of goods and services. In the scope of industrialization, automation is a step beyond mechanization...

 sentry gun
Sentry gun
The sentry gun is a gun that is automatically aimed and fired at targets that are detected by sensors. The earliest functioning military sentry gun was the Phalanx CIWS, a radar-guided gatling gun platform that defended ships from missiles....

 (rather than a simple static trip-mine), a misconception shared even with Western intelligence agencies. In fact, no such technology existed during the lifespan of East Germany, and the mine was actually more similar in capability to an oversized spring gun, but the rumors provided an additional psychological deterrent
Psychological warfare
Psychological warfare , or the basic aspects of modern psychological operations , have been known by many other names or terms, including Psy Ops, Political Warfare, “Hearts and Minds,” and Propaganda...

 to would-be border crossers. From 1973 onward, the mines were enclosed in a plastic box housing for protection from the elements, further concealing their design from onlookers.

Oversensitivity of the trip wires proved to be a vexing challenge throughout the service life of the SM-70. The wires proved sensitive enough to trigger the mines if a bird rested on the wire, resulting in a large number of accidental detonations in early deployment; this led to an inert "bird wire" being strung slightly above the first actual trip wire to give the birds something to rest on without risking a discharge. This proved only somewhat effective, as the mines still regularly suffered unintentional detonations due to heavy winds, deer and other animals, snow and ice accumulation, falling tree branches, bramble
Bramble
Brambles are thorny plants of the genus Rubus, in the rose family . Bramble fruit is the fruit of any such plant, including the blackberry and raspberry. The word comes from Germanic *bram-bezi, whence also German Brombeere , Dutch Braam and French framboise...

 overgrowth, and rock-throwing West Germans.

Michael Gartenschläger

The true nature and purpose of the SM-70 was eventually determined after Hamburg
Hamburg
-History:The first historic name for the city was, according to Claudius Ptolemy's reports, Treva.But the city takes its modern name, Hamburg, from the first permanent building on the site, a castle whose construction was ordered by the Emperor Charlemagne in AD 808...

 resident and former East German political prisoner
Political prisoner
According to the Longman Dictionary of Contemporary English, a political prisoner is ‘someone who is in prison because they have opposed or criticized the government of their own country’....

 Michael Gartenschläger — who had led a party of six defectors in a successful escape across the border in 1971—successfully infiltrated the border defenses near Büchen
Büchen
Büchen is a municipality in the district of Lauenburg, in Schleswig-Holstein, Germany. It is situated on the Elbe-Lübeck Canal, approx. 13 km northeast of Lauenburg/Elbe, and 45 km east of Hamburg....

 on 30 March 1976, dismantled a live SM-70 from its mount, and returned safely to present the mine to West German authorities for inspection. Against official advice, Gartenschläger made a second successful trip to the same section of fence on 23 April and retrieved another live SM-70. The event made West German newspapers, and tipped off the border guards that the sector was being targeted for sabotage. A special 29-member task force was assembled to prepare concealed firing positions in the area and set up an ambush for the culprit. On 1 May 1976, as Gartenschläger was climbing over the East German fence for his third attempt, he was captured in the beam of a searchlight
Searchlight
A searchlight is an apparatus that combines a bright light source with some form of curved reflector or other optics to project a powerful beam of light of approximately parallel rays in a particular direction, usually constructed so that it can be swiveled about.-Military use:The Royal Navy used...

 and blown off his ladder by a burst of automatic gunfire. There was no request for surrender.

Following the recovery and analysis of the intact SM-70 in 1976, international public outcry led to diplomatic protests with the East German government. When the hard-currency starved GDR approached the West for a loosening of relations in exchange for trade, the sole sticking point in the West German platform was the removal of the SM-70. This suited the GDR as well, since Erich Honecker
Erich Honecker
Erich Honecker was a German communist politician who led the German Democratic Republic as General Secretary of the Socialist Unity Party from 1971 until 1989, serving as Head of State as well from Willi Stoph's relinquishment of that post in 1976....

 saw the SM-70 as troublesome, expensive and bad for the GDR's image, and intended to remove them shortly anyway (along with the rest of the buried mines) when he implemented his plan for a fully "electronic" border defense grid. Honecker's plan eventually fell through due to lack of funding, but the SM-70 continued to be removed as per the agreement, being replaced with extra buried PMN mines, which remained in place until the fall of East Germany in 1989.

See also

  • Spring-gun
    Spring-gun
    A spring-gun is a gun, often a shotgun, rigged to fire when a string or other triggering device is tripped by contact of sufficient force to "spring" the trigger so that anyone stumbling over or treading on them would discharge it and wound themselves....

  • M18 Claymore
    M18A1 Claymore Antipersonnel Mine
    The M18A1 Claymore is a directional anti-personnel mine used by the U.S. military. It was named after the large Scottish sword by its inventor, Norman A. MacLeod...

  • MON-50
    MON-50
    The MON-50 is a claymore shaped , plastic bodied, directional type of anti-personnel mine designed and manufactured by Russia. It is designed to wound or kill by explosive fragmentation...

  • MRUD
    MRUD
    The MRUD is a plastic bodied, convex rectangular directional type Anti-personnel mine designed to wound or kill by fragmentation. It is broadly similar to the M18A1 Claymore mine....


External links

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