Emerging Landmines
Clearance Technologies

Columnist Col (Retd) EAS BOKHARI researches the new

concepts and technologies in the clearing of land-mines

In the Manila Seminar last year (21 to 23 July 1997), one of the key speakers Maj Gen Dipanker Bannerjee, AVSM (Retd) Indian Army who runs a think tank in Delhi spoke thus about mines and their operational utility vis-a-vis social cum humanitarian nuisance in post battle era:

• Land-mines and especially the AP (Anti Personnel) have only a limited and marginal role in combat.
• Not enough study has been done within military circles to establish its cost effectiveness vi a vis cost to civilian lives.
• Their effect as a tool of mass and indiscriminate harassment after wars far outweigh any combat value which they might have. The appalling human consequences are far too much.
• The unethical and indiscriminate use of mines is widespread and is likely to continue.
• Remotely delivered mines are a new and deadly generation of mines.
• Even though the military effectiveness of AP mines is questionable, the cheapness and rapid laying capability appears as an attractive military option.
• Other options as barrier to movement need to be developed.

As a working figure there are at least 100 million land mines placed out in the world and according to FOA-Sweden there are just as many in the world stockpiles. A total of about 10,000 mines are removed worldwide but at least two million are laid. About 10,000 people die annually as a result of mines Sand most of them are children.

Ironically whereas there has been a very considerable improvement in the mine technology, little improvement has been noticed in the mine clearance and demining operations -which remain terribly conventional. The most prevalent method which is not only slow -’Prodding’ is neither cost effective nor it is 100 percent safe. It is too old and naive I suppose. It is about time that more functional methodology is developed to deal with the burgeoning land mine problem especially the AP mine predicament.

I intend to cover two new approaches to the land mine detection and demining operations - the first one is a joint German-Swedish approach and the second one is the MIT approach.

FOA - which is the Swedish organ of defence research seems to have taken initiative to develop a research programme directed towards mine detection and clearance. (This is definitely not prodding). FOA has worked up a joint collaboration with the large German defence industry group Deutsche Aerospace (DASA), and it appears that the work of the two agencies is more or less complementary.

To explain it a little more, ‘for example in the area of sensor technique where FOA has worked on ground based systems for localising individual mines - DASA has worked on developing airborne systems for identifying entire minefields’. In a nutshell, the joint programme consists of two major thrusts as below:

• ORAD i.e. Ordinance Recovery and Disposal and
• HPM i.e. High Power Microwaves.

The two proposals involve about 500 million Swedish Crowns and are to be spread over five years time. The second thrust i.e. HPM, and here some sort of technical jargon cannot be avoided involves ‘..... high effect pulsed microwaves (gigawatt and above) as non-lethal weapons for the UN troops. Such weapons can disable electrical and electronic equipment without injuring people ... However HPM can also be used for mine clearance, since mines are often sensitive to strong microwave radiation ....’ And explaining it a little further ‘....The main emphasis of the proposed project is on applying new technologies and unconventional methods in order to solve or reduce problems regarding demining. Examples of such technologies include signal processing and algorithms for the analysis of sensor information which has been developed for ‘smart bombs’ and other active targeting devices, and data fusion, that is, coordinated analysis of information from different types of sources. The use of this type of knowledge which has been developed by way of state financed projects in a number of different countries also facilitates the ‘dual use’ of defence technology.’

Luckily the latest (GPS) which is a global navigation system by satellites is of very great help as it gives an almost instant and accurate fixation. As would be seen the primary task of this exercise is to locate and identify mines including the wily and difficult to locate non-metallic mines. Unfortunately there is presently no single sensor which can reliably detect and identify a mine under all circumstances. In fact all existing mine detectors are based on a single sensor. The problem in fact needs the use of several different sensors and simultaneously. The Swedish/German venture is to develop an operational ground based prototype of such a detector.

Some of the technologies for this work are as below:

• Ground Penetrating Radar. It is a good technology and is operable both in wet and dry terrain. The impulse radar has a good range but poor resolution and therefore cannot locate very small objects.
• There is pretty good scope for magnetic sensors and even three dimensional effect can be produced (detectors made from super conducting materials could be used.) Another option could be the seismic and acoustic sensors which are used in oil exploration and geophysical surveys.
• Then there is the futuristic bio sensor or the ‘scent’ method which could be quite promising.

(All these sensors, of sure, have varying degrees of resolution).

Finally a few words about the Impulse Radar on which the FOA started work in the mid 1980’s. A working prototype of this radar is already on the ground. A schematic layout of the contraption is indicated. It is rather difficult to obtain exact information about what the radar can see, i.e. whether it is a mine, a stone, a pipe or a cable. In order to solve this problem extremely advanced signal processing must be used. The impulse radar must be capable of being used after a short spell of training. And if it is to be carried by a soldier it should not weigh more than 10 Kg. The radar has also been tested when mounted on a vehicle. There are also plans to use it from a mini helicopter flying at an altitude of one or two meters.

Impulse radar - dowsing rod in the mine field

The atlas of land mines is a long one, and nearly 700 different models of mines are found worldwide. Their designs differ rather widely. Perhaps the greatest manufacturers and sellers of these dirty weapons which are equally inhuman are such big powers as former Soviet Union, China and the United States of America. To this list of countries we could add Czechoslovakia, France, Italy and Yugoslavia.

The major practical distinction among the different types of mines is their intended target. Anti-tank mines are big enough to topple and destroy vehicles and may carry as much as 10 pounds of High Explosive (HE). But then there are comparatively harmless looking but more prevalent anti-personnel mines (AP), which are the size of a can of tuna, and might contain less than an ounce to half-pound or more of HE. These are designed to kill individuals or small groups of people on foot. Mines may also differ in the cruel cunning of their designs-and some even contain countermeasures of demining. And there are some larger US mines which may even emit directed fragments within a lethal radius of 90 feet or so. The large US Claymore mine used in Vietnam, for instance, has a 150-foot lethal range for persons walking into its line of fire.

This presentation is mainly devoted to the more pernicious AP mine which creates significant human problems and societal calamity. Surprisingly very little has been done to rid the world of these mines. It is good to know that this gigantic problem is now being tackled by renewed vigour both by NGOs and the governmental agencies. The Ottawa process is one of the more potent thrust in this direction.

Mines are a nuisance, a hidden and buried killer or at least an incapacitator, but these are found everywhere. Perhaps the most pernicious of these are the Anti-personnel mines (AP) whose main targets are the poor ill equipped civilians and the tongue-tied animals. Their victims include many children and elderly villagers in the poor nations.

Although a sort of a ‘Brute Force’ technology is employed in military/operational mine clearance or for making lanes in a minefield - this technology may not be workable in the millions of mines which lie buried around the world.

The size of the problem should be clear from the following passage taken from the ‘Technology Review Volume 100 No 7 of October 1997.’

‘..... According to United Nations estimates, more than 100 million mines lie buried around the world, outlasting their war, abandoned long ago, yet awaiting their unintended victims for as long as decades. An-anti personnel (AP) mine costs only a few dollars to produce, but it now costs a hundred times that sum to remove it. In Cambodia alone, where some of the world’s densest minefields lay, 10 million mines lurk within an area the size of Missouri. Last year three thousand workers cleared land mines from 12 square kilometers of Cambodian land at a cost of $8 million. They were not overpaid. But at that rate, even if someone were willing to foot the bill, demining Cambodia would take some 10,000 years. To make matters worse, participants in today’s conflicts are emplacing new mines at the rate 10 or more times the current yield of the deminers, who now clear perhaps 100,000 mines per year world wide.’ A chronic gargantuan and growing crisis is at hand.

The present method of detecting mines and which is being generally employed by NGOs and others working in this field is the age-old ‘creep and probe’ method which is both unaffordable, tiresome, painfully slow, expensive and quite dangerous on occasions. It is perhaps not quite fool-proof either.

The present universal method of mine clearance consists of the use of a metal detector, hand held probe and explosive charge is accepted as the most reliable demining method despite its laborious and perilous nature. The detection method works as most of the mines have some metal parts (although plastic mines defy this to a large extent.) ‘The bottleneck occurs, however, in discriminating between the few real mines and the many false alarms. Given the wide array of metal objects that can reside in the soil of former battlefields, the false alarm rate can run as high as 1,000 false positives to one real mine.

The result is the bulk of the searcher’s time is spent on painstaking exposure of harmless metal scraps, and after hundreds of false alarms, the job becomes even more perilous: one surprise mine can maim or kill deminers whose patience has flagged just once, causing them to misjudge the form they uncover.’

And pointed out above the plastic mine is a real menace, and the growing use of plastic-encased mine poses ominous threat of false negatives: that real mine will remain silent and deadly even when swept by metal detector.

This presentation is more concerned with the AP mines-and how to deal with them - and what emerging technologies could be employed to replace the conventional methodology. As it is ‘the damage AP mines inflict - disabling victims for months or for life is economically worth orders of magnitude, more than their cost of a few dollars apiece. By that cruel calculus, they are cost effective even against irregular infantry or the poorest of the unarmed villagers. Because of their prevalence and availability, because they tend to be placed more randomly, and because they make up the bulk of the lingering scourge, these AP mines are our quarry, the particular focus of humanitarian demining efforts.’

It is surprising that the technique of demining remains primitive notwithstanding the damage caused by the mines. Some sane generals have even called the use of mines as a violation of civilized warfare. Of late there is a thrust on the banning of land-mines and the impetus has gained more ground during the last five years or so, and concerted efforts are being made and recently both at Oslo and Ottawa steps have been taken towards global ban on land- mines. All the same, the problem of clearing the ones which are there buried worldwide needs rather serious attention.

A recent assault on the problem seems to have been launched in an MIT Programme in Science and Technology for International Security at the American Academy of Arts and Sciences in Cambridge, Mass. The session drew a disparate group of participants including the field workers from Laos with many years of demining experience, researchers with expertise in physics, chemistry, electric engineering, material sciences and anthropology; several people working on high-tech mine detection schemes and military demining experts.

The concensus of this rather elegant gathering is summed up in the paragraph below:

‘...... Our unexpectedly hopeful view, bolstered by subsequent study is that while no silver bullet appears to be on the near horizon to solve the demining problem, promising technologies at hand can offer significant help.... A number of developing techniques, for instance, detect land mines by sensing physical and chemical properties other than metal content, thereby significantly aiding in the task of reliably discriminating mines from metal scrap. Our analysis indicates that if nations lend enough support, affordable technologies could be available in the field within five years to undertake a humanitarian demining effort on an unprecedented global scale ...’

Some of the suggested technologies which are a real improvement on the present ‘Creep and Probe’ technology are presented in the concluding part. These technologies appear to be both time and effort efficient and are worth developing to their full fruition and trial.

The present demining procedure, or the traditional anti personnel demining drills are least time efficient besides being expensive and even dangerous at times. The ‘creep and probe’ methodology - as it is rightly dubbed can just detect metal and not the mine itself. And now the clever mine manufacturers have started using plastic mines to defeat this technique.

The new approach to demining which is being perfected at the MIT and which should be operative in the next couple of years time is seen as more scientific and efficient way of dealing with the AP mines. Very broadly the technology i.e. the Emerging Technology (ET) consists of the following:

l Detection of mines by a variant of the electrical metal detector (already in use) - called the ‘Meandering Winding Magnetometer’ (MWM),

l Swift and safe excavation by a device called an ‘air knife’ and,

l Detonation by a cheap and easily deployed foam like explosive.

These technologies as would seem, still require field testing and refinement.

‘The basic operating principle of the new MWM detector is the same as that of the conventional metal detectors that use a pulse-electromagnetic induction sensor. Conventional detectors generate an electromagnetic field and sense if it is disturbed by conducting material in their path, MWM detectors generate a varying magnetic field that excites currents in metallic objects that align primarily in one direction and can be read by the detector.’

Of sure, this new detector is slightly larger than the existing detector and can thus obtain a crude hint of the size and shape of a buried metallic object by combing readout of these so called eddy currents.

The MWM detector now being developed by Jentek Sensors Inc. of Brighton, Mass: can reportedly determine the rough size, shape depth of burial, and type of material of the outer shell of a buried metal object. Laboratory evidence has shown that the device can provide enough information for an experienced operator to discern whether a buried object is mere clutter, a mine, or a large piece of unexploded ordinance.

‘Field tests of a first-generation MWM prototype indicate that it can lower the false-alarm rate by a factor of 5 to 10 below that of a conventional metal detector. Given such discriminating power, a refined version of such an MWM device could reduce the time spent examining a square meter of scrap rich ground from 10 to 20 minutes to a fraction of a minute ...’

Once a mine is detected, the air knife, which is now commercially available - although not in a field ready form, offers a very significant improvement in efficiency and safety over the ‘stick’ commonly used in today’s demining efforts. Its working is something like this. The airknife blows high pressure air through a small hand held probe and can blow away most dirt to expose mines without disturbing them enough to detonate them.

Existing air knives are powered by a 3-Horsepower gasoline engine like those that run lawnmowers, and cost a few thousand dollars. ‘A version adapted for demining could replace the simplest manual probes, greatly speeding up a searcher’s ability to expose a mine while improving safety at the same time by obviating the need to dig the ground with a stick.’

And in the final phase the use of the product ‘Lexfoam’ will also aid demining efforts. This product is something like a shaving cream in appearance, is a dilute dispersion of an explosive within a foaming plastic substance. ‘Lexfoam’ is safe and simple to apply and can be set off by an ordinary detonation cap, removing the delicate and hazardous task of wiring a charge onto an unearthed mine. It is estimated that the use of such a product (to blow up the exposed mine) would considerably speed up the overall deeming process - perhaps by as much as a factor of 2 to 5.

The air knife would need an air compressor carried on a hand drawn wheeled cart, packaged into a backpack-like portable unit or built into a small motorised vehicle that carries the MWM metal detector, air knife, and ‘Lexfoam’ dispenser. In a small, relatively new humanitarian demining unit at fort Belvoir in Virginia, the US Army is presently assembling such a vehicle that combines an MWM detector, compressor, air knife an operator’s plastic shield to protect against explosion, an air operated woodcutter, and a Lexfoam dispenser - all in one. Colonel Harry (Hap) Hambric, who directs development and testing of this unit ‘estimates that the combined use of these relatively simple technologies, where terrain is suitable, could speed up demining by a factor of 10 within a year or two, and by another factor of 10 with refinements to come.’

Another innovation is the proposed use a small sized tinted roller with hinged spring loaded prods that can set off AP mines as it passes over them. The rope towed (or winched) roller is simple, inexpensive and easy to repair. It contains hundreds of closely spaced, stiff, spring mounted fingers able to penetrate upto 25 cm into the ground; the roller is towed back and forth by animals or motor vehicles kept at a safe distance.

Tests under controlled conditions performed by the US Army at Fort Belvoir in 1995 proved that the roller was capable of exploding or otherwise destroying small anti personnel mines even in the mud bottom of rice paddies and other soft floored terrain. With some design modifications the roller could be configured to operate with same performance on harder surfaces including areas bearing light foliage.