Demining

Hydrema mine clearing vehicle

Demining is the process of removing landmines or naval mines from an area. There are two distinct types of mine detection and removal: military and humanitarian.

• In the combat zone, the process is referred to as mine clearance. The priority is to breach the minefield quickly to create a safe path for troops or ships. Speed is vital, both for tactical reasons and because units attempting to breach the minefield may be under enemy fire. In this situation, it is accepted that mine clearance will be imperfect and there may be casualties from undiscovered mines.

• In times of relative peace, the process of mine removal is referred to as demining. This is a thorough, time-intensive process that seeks to locate all mines so that the land or sea area may be safely returned to normal use. It is vital that this process is exhaustive. Even if only a small handful of mines remain undiscovered, then demining can actually lead to an increase in civilian mine casualties as local people re-occupy an area they previously avoided in the belief that it has been made safe.

MineWolf tiller-based demining machine deployed in Sudan

According to the doctrine of the U.S. and other armies, mine clearance is carried out by combat engineers and demining is carried out by Explosive Ordnance Disposal (Bomb disposal) units. However, demining is most frequently done by civilian organisations for humanitarian reasons. Humanitarian Demining is one of the five components of Mine Action; the others being Advocacy, Mine Risk Education, Victim Assistance and Stockpile Destruction.

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Digger Mini Flail for Mine Clearance

Currently, the main methods used for humanitarian demining on land are manual detection using metal detectors and prodders, detection by specially trained mine detection dogs, and mechanical clearance using armoured vehicles fitted with flails, tiller or similar devices. In many circumstances, the only method that meets the United Nations' requirements for effective humanitarian demining, the International Mine Action Standards, [1] is manual detection and disarmament. While some mines have significant metallic content and are fairly easy to detect with metal detectors, many anti-personnel mines and some anti-tank mines have a very low metal content and are much more challenging to locate. The 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$400 million was donated . It takes one to two million US$ to clear a square kilometer of land in most environments. Often, clearing landmines is a necessary condition before other humanitarian programs can be implemented.

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

Foerster Minex 2FD 4.500 Metal detector used by the French army.

The first step in manual demining is to scan the area with metal detectors, [2] 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. 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. 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

Honey Bees

Recent research by the University of Montana has revealed that honey bees can, with minimal training, be used to detect landmines with a far greater accuracy and far higher clearance rate than dogs or rats.

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

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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 used in land mines are very nitrogen rich when compared with other materials. 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.

Acoustic detection

It is possible to detect land mines by directing sound waves at the area to be demined, which causes the land mines to vibrate, and then using a laser to search for vibrations on the surface by means of the Doppler shift - this technique is termed Scanning Laser Doppler Vibrometry. Such devices have been constructed e.g. at the University of Mississippi , at MIT and by the Keyser-Threde Company .

Removal methods

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Colombian soldier minesweeping. Colombia has the highest rate of victims by mines

• 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 ethylenediamine) reacts with TNT to generate heat. The compound that results from this reaction can then be combusted 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. Some modern mines are resistant enough to shock and overpressure to make this an ineffective technique.

• Mechanical demining effectively combines mine detection and removal into one operation. It makes use of a special vehicle that is driven through the mine-field, deliberately detonating the mines it drives over. These vehicles are designed to withstand the explosions with little damage. Some are operated directly with armour to protect the driver; some are operated under remote control. There are two ways of detonating the mines - mine rollers and mine flails. The roller method originated during World War I and the flail method during World War II but both are still used. Neither system is completely reliable and both will leave undetonated mines, requiring the minefield to be rechecked by another method. Mine flails may only be 80% effective; often good enough for military mine clearance, but well below the 99.6% standard set by the United Nations for humanitarian demining.

• Modified long-arm demining bulldozer is being used in numbers of countries, it has capability to remove woods before demining and has endurance not only from antipersonnel landmines but also from antitank landmine & claymore bullet mine. Its long arm gives the benefit to reduce the damage at main body, especially at operating seat, and 3.5in (9cm) thick bulletproof glass gives enough protection of operator from claymore mines. The bulldoze system has the advantage from the other demining machines, because bulldoze machine can be used for cutting woods with rolling blades unit, exploding the mines with rolling chain unit, and even for bulldozing the land for daily civilian use (farmland, school etc.) with normal shovel unit as "bulldozer" after demining operation.

• 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.

• Using a helicopter dragging a plow to overturn or detonate mines. This has the problem of bringing down the helicopter when the plow snags onto objects such as large rocks, but has been corrected by use of pressure-sensitive plow rakes which release when over-pressured. This does however, affects its effectiveness as mines planted in hard ground or near rocks will not be detonated.

• Cutting holes in the mine without detonating its contents

• 
  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].

See also

• Mine roller
• Mine plow
• Humanitarian Demining Research at the University of Western Australia
• Demining Robots
• Demining Machine
• Mine clearance agencies
• Kiyoshi Amemiya - project chief for bulldoze system development, who is working for demining jobs & for making lectures of the unhumanity landmines has.

External links

• Westminster International Mine Clearance solutions Mine Clearance Machines
• DEMIRA Deutsche Minenraeumer e.V. German Mine Clearers
• Demining with Africa`s Sniffer Rats (APOPO)
• Swiss Foundation for Mine Action (FSD), one of the humanitarian mine clearance organisations
• Digger Foundation, Demining technologies - swiss tools for mine clearance
• European Commission action programme against antipersonnel landmines
• EUDEM The European Union in humanitarian DEMining - technical research and development database
• Geneva International Centre for Humanitarian Demining
• Mine Action Information Center at James Madison University
• International Test and Evaluation Program for Humanitarian Demining
• MineWolf Systems, Swiss-based provider of mechanical demining machines