Minenräumung

Demining is the process of removing landmines or naval mines from an area. There are two distinct types of mine detection and clearance: military and humanitarian. In a military context the priority is to breach the minefield quickly to allow safe passage for troops or ships. For example a flail attached to the front of an armoured vehicle, or an armoured bulldozer might be used to clear a path through a field of land mines. Civilian or humanitarian mine clearance by contrast requires that all mines are cleared so that the land or sea area may be safely used.

Hydrema mine clearing vehicle

Humanitarian Demining is one of the five components of Mine Action; the others being Advocacy, Mine Risk Education, Victim Assistance and Stockpile Destruction.

While anti-tank mines often have significant metallic component and are fairly easy to detect with metal detectors, anti-personnel mines, with a very low metal content, are much more challenging to locate. Currently, the only method that meets the United Nations' requirements for effective humanitarian demining, the International Mine Action Standards, [1] is manual detection and disarmament. This process is typically slow, expensive, and dangerous, but new technologies may provide effective alternatives.

It is estimated that US$1 billion per year would be sufficient to completely demine globally, but in 2000, only about US$400 million was donated (with about US$250 million from the United States). It takes one to two million US$ to clear a square kilometer of land in most environments. Often, clearing landmines is a necessary condition before other humanitarian programs can be implemented.

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History

The electronic land mine detector was invented towards the end of 1941 by Lieutenant Josef Stanislaw Kosacki, a signals officer with the 1st Polish Army Corps . At the time Kosacki was stationed in Fife (Scotland) after the defeat of the Polish Army during World War II. The exiled Polish Army had been drafted into defend the Fife coast against possible Nazi invasion.

Detection methods in use for civilian demining

Manual detection with a metal detector

Metal detector used by the French army.

The first step in manual demining is to scan the area with metal detectors, which are sensitive enough to pick up most mines but which also yield about one thousand false positives for every mine, and cannot detect landmines with very low metal content [2]. Areas where metal is detected are carefully probed to determine if a mine is present, and must continue until the object that set off the metal detector is found. Technologies that improve safety include large, pillow-like pads strapped to the bottoms of shoes that distribute weight and dull the impact of footsteps, as very slight disturbances of the ground can tip off old, unstable, or intentionally sensitive mine triggers.Vorlage:Citation needed Demining can be safer than construction work if procedures are followed rigorously.

Dogs

Well-trained dogs can sniff out explosive chemicals like TNT in landmines, and are used in several countries.

Detection methods under development for civilian demining

Biological detection

Rodents

Recent experiments with the Gambian giant pouched rat have indicated that it has the required sensitivity to smell, can be trained reliably with food-reward incentives, and is typically too small to set off the mines.

Additionally, experiments with electrode-guided rats suggest that demining could one day be accomplished by guiding "ratbots" into areas that humans are unable to reach.

Plants

Datei:Redandgreen1.JPG

These plants turn red when exposed to nitrous oxide revealing the location of landmines.

The mustard Arabidopsis thaliana, one of the best studied plants in the world, normally turns red under harsh conditions, but using a combination of natural mutations and genetic manipulation scientists from Danish biotechnology company Aresa Biodetection, created a strain that only changes color in response to the nitrous oxide that leaks from landmines and other explosives. Because nitrous oxide can also be formed by denitrifying bacteria, there is some risk of false positives using this technique, and researchers are attempting to make the plant less sensitive. The plants would aid demining by indicating the presence of mines through color change, and could either be sown from aircraft or by people walking through demined corridors in minefields. As of February 2005, no studies have been conducted with actual landmines, though successful studies have been done in greenhouses. In order to prevent the spread of this genetically modified organism into the wild, the plants have been further modified so that they will only sprout when provided with an external growth factor.

Bacteria

A bacterium has been genetically engineered to fluoresce under ultraviolet light in the presence of TNT. Tests involving spraying such bacteria over a simulated minefield successfully located mines. In the field, this method could allow for searching hundreds of acres in a few hours, which is much faster than other techniques, and could be used on a variety of terrain types. While there are some false positives (especially near plants and water drainage), even three ounces of TNT were detectable using these bacteria. Unfortunately, there is no strain of bacteria capable of detecting RDX, another common explosive, and the bacteria may not be visible under desert conditions. Also, well-constructed munitions that have not had time to corrode may be undetectable using this method.

Marine mammals

The U.S. Navy Marine Mammal Program uses sea lions and dolphins, among other species, in the detection of seamines.

Nuclear detection

The vast majority of explosives are very nitrogen rich when compared with other materials. An important exception to this rule of thumb is TATP (which is too unstable to be used in landmines). It is possible by elemental analysis by neutrons to detect nitrogen by means of the reaction

^{14N + n → 14C + p + γ (10.8 MeV)}

The system works by subjecting the mine to thermal neutrons while searching for the very rare and high energy gamma photons; these photons will only be observed when an object containing nitrogen is being subjected to the neutron irradiation. One possible neutron source is californium-252 which undergoes spontaneous fission. A better neutron source is to use a sealed tube electrostatic D-T neutron generation tube, this has the advantage that the tritium is much less radiotoxic than the californium so in the event of an accident such as an explosion the nuclear mine detection equipment would pose a smaller threat to humans. This type of explosive detection has been proposed for use in airport security and for the detection of explosives in trucks coming into military bases.

Landmine sensing vehicle

A low cost robotic vehicle is being developed which will ease land mine detection and thus saving many lives. The Unmanned Land mine Sensing Vehicle (ULSV) is fitted with a proximity detector and a micro controller is used to control all the operations. It is programmed to move in all directions, scanning for the existence of landmines. If any landmine is found, the ULSV sends the information using a FM transmitter interfaced to it. The vehicle is operated with battery power. At the base station a mini-computer receives information about the location and distance of the mine. The entire system is rugged and is capable of detecting mines even in unusual terrains. The project could be developed by incorporating GPS to improve communication accuracy and by making the vehicle solar-powered. Moreover, the vehicle is low cost, so it can be replaced if it sets off one of the mines.

Removal methods

• Manually disarming them.
• Remote burning of the explosive, where possible it is better to burn the explosive without detonation. Diethylene triamine (a close relative of ethylene diamine) reacts with TNT to generate heat. The TNT can then burn without detonation. It has been reported that this amine is hypergolic with TNT, Tetryl, Composition B and other TNT based explosives. But it does not react in this way with RDX or PETN based explosives in the same way. Other nitrogen-containing organic ligands (eg pyridine, diethylamine and pyrole) are known to be hypergolic with TNT.
• Carpeting the suspected minefield with an artillery barrage. Although some modern mines are resistant enough to shock and overpressure to make this an ineffective technique.
• Driving a heavily armoured vehicle like a tank or bulldozer through a minefield to deliberately detonate the explosives. One of the more effective methods uses a flail—a set of long chains attached to a rotating drum held out on arms across the front of the tank—to beat the ground. During World War II, to counter the use of armoured vehicles to clear mines, the Germans improvised anti-tank mines by burying an artillery shell deeper in the ground attached to a sensor some distance behind the shell, so that when the tank flail or dozer blade went over the sensor the shell exploded under the tank. Today, minefields are sometimes set with a mix of anti-personnel and anti-tank mines. The flail method may only be 80% effective; often good enough for military demining, but well below the 99.6% standard set by the United Nations for humanitarian demining.
• Using a Bangalore Torpedo to clear a path through a minefield. This can also be done using the Antipersonnel Obstacle Breaching System, a hose-pipe filled with explosives and carried across a minefield by a rocket.
• Cutting holes in the mine without detonating its contents

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  World War II Sherman Crab mine-flail tank under test, 27th April 1944.
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  Protective clothing
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  Shoes of protective clothing
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  demining robot of the French army

Test and Evaluation

A large-scale international effort has been made to test and evaluate existing and new technologies for humanitarian demining, notably by the EU, US, Canadian and Japanese governments and by the Mine Action Centres of affected countries. [3],[4], [5].

See also

• Mine roller
• Mine plow
• Mine clearance agencies

External links

• Demining with Africa`s Sniffer Rats (APOPO)
• Swiss Foundation for Mine Action (FSD), one of the humanitarian mine clearance organisations
• Geneva International Centre for Humanitarian Demining
• James Madison Uiversity Mine Action Information Centre
• International Test and Evaluation Programme in Humanitarian Demining

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