|
|
MINEFIELDS |
|
Mines and Minefields -- Defining the ProblemPhotographs of MinefieldsbbbbbbbbbbbbbbbbPhotographs of Mines
Global landmine problem and its effects (updated January 2000)About 70 countries are affected to varying degrees by land mines (according to the UN, January 1998). The Red Cross (1996) estimated that mines and other unexploded ordnance are killing between 500 and 800 people and maiming 2000 others per month, mainly innocent civilians who had little or no part in the conflicts for which the mines were laid. Carefully targeted efforts to clear land mines can significantly reduce these statistics. Some countries have banned the use of landmines and others are supportive of a complete ban. However, their low cost ($3 - $30) and the large numbers in existing stockpiles make them an attractive weapon for insurgency groups which operate in many countries with internal conflicts-the most common cause of wars today. Mines are often used by renegrade groups to harass civilians in order to extort money and food. They are also used for self-defence by villages and groups of people travelling in many districts where civil law and order provides little effective protection. Many countries retain massive landmine barriers on their borders or near military installations. Some of the most severe landmine problems exist in Egypt, Angola, Afghanistan,, Bosnia, Cambodia, Laos, Kuwait, Iraq, Chechnya, Croatia, Somalia, Sudan, Ethiopia, and Mozambique. Apart from deaths and injuries to people, the major effect is to deny access to land and its resources, causing deprivation among the affected populations. Millions of refugees cannot yet return home, and impose huge burdens on neighbouring countries (1.5 million Afghans in Pakistan, for instance) and require major international relief efforts. Regardless of any efforts to stop the further use of landmines, the safe restoration of productive land is an urgent issue in affected regions. While current clearance programmes measure results in terms of a 10 - 20 square kilometres per year, up to 60% of available agricultural land is unusable in some regions of the affected countries. The widely quoted statistics suggesting that there are as many as 110,000,000 mines are now being questioned [Jefferson 1997]. The original statistics were prepared in a great hurry by the US State Department in 1994. Mine clerance teams in the field were anxious not to under-estimate the problem, so they applied generous factors to cover uncertainties. Whereas 10,000,000 mines were thought to have been laid in Afghanistan, current estimates are less than 1,000,000. To further compound the problem, statistics have been quoted in terms of the cost to remove each mine and the rate of removal (up to $1,000 each, 20,000 mines and UXO's per year in Afghanistan cleared) rather than the cost to clear minefields (per quare metre). Thus one might deduce from published statistics that the problem in Afghanistan will cost $10,000,000,000 and require perhaps 500 years of clearance work. According to UN staff directing the mine clearance programme in Afghanistan, about 10 years work will clear most of the mines from high priority areas and enable the Afghan population to start rebuilding their country. Reconstructing roads, towns and other infrastructure will take longer, of course. Many mines will be left in or on the ground, but they are concentrated around military posts on hill-tops and in mountain areas which contribute little to economic activity and which can be left until other more important reconstruction is well under way. Elsewhere, many millions of the land mines included in statistics lie along national borders or around vital installations such as airports where security is seen as a major local problem. Governments are not yet ready to remove these mines. The main implication is that the land mine problem has been overstated in many places by perhaps a factor of 10 or more in terms of cost and time needed to clear the mines which are causing current problems. It is still a major problem, of course, but not as big, in relative terms, as the current publicity suggests. One should remember that perhaps 200,000 or more people die in road accidents each year around the world, and perhaps as many as 4,000,000 die from preventable Malaria. Land mines are still a major problem. However, the
problem can be fixed for what is. in international terms, a modest sum
of money. About $4,000,000,000 spent over 10 to 20 years would deal
with most of the land mine problems we now face. The image files are 50-150 kbytes each. Click on a picture link: it will come up in a separate window so you can go on reading while you are waiting for it to arrive. Two types of mine (click for picture). Left a fragmentation mine which is activated by a trip wire which pulls out the firing pin, detonating the main charge around the detonator. The outer shell breaks into lethal fragments which spread to a radius of 50 metres when the mine explodes. Right: a small blast mine (about 7 cm diameter) activated by foot pressure which causes the fibre-reinforced plastic cone shaped spring washer to snap down, firing the detonator which initiates the explosion of the surrounding explosive. The only metal parts are the firing pin and the detonator shell. Safety pins and time delay mechanisms have not been shown. The most common buried mine is the PMN (Russian) which has many more large metal components and is easy to detect and very sensitive, requiring as little as 1 kg force to set it off if disturbed. See our page with some pictures of mines. Land mines are usually very simple devices which are readily manufactured anywhere. There are two basic types of mines:[King 1996] anti-vehicle or anti-tank (AT) mines, and anti-personnel (AP) mines. AT mines are comparatively large (5 - 15 kg explosive), usually laid in unsealed roads or potholes, and detonate when a vehicle drives over one. They are typically activated by force (>100 kg), magnetic influence, or remote control. AP mines (AP) are much smaller (80 - 250g explosive, 7 - 15cm diameter) and are usually activated by force (3 - 7kg) or tripwires. There are over 700 known types with many different designs and actuation mechanisms. There are two main categories of AP mine. A blast mine is usually small, and detonates when a person steps on it: the shoe and foot is destroyed and fragments of bone blast upwards destroying the leg. However, the blast effects are very localised. With suitable protection, a deminer can escape serious injury as long as his hand is more than 30 cm from the explosion, and most of the blast energy is directed upwards. When a fragmentation mine explodes, metal fragments are propelled out at high velocity causing death or serious injuries to a radius of 30 or even 100 metres, and penetrating up to several millimetres of steel if close enough. Simple fragmentation mines are installed on knee high wooden posts and activated by tripwires (stake mines). Another common type of fragmentation mine (a bounding mine) is buried in the ground. When activated, it jumps up to groin height before exploding. Mines of one type have often been laid in combination with another type to make clearance more difficult: stake mines with trip wires may have buried blast mines placed around them. Humanitarian demining operations face many complications which need to be understood if we are to work towards useful improvements. The mines have often been in place for 5 or more years, may be corroded, waterlogged, impregnated with mud or dirt, and can behave quite unpredictably (UNOCHA 1996). Stakes which carried fragmentation mines may have fallen over, and trip wires may be caught up in overgrown bushes, grass or roots. A wind gust may sway a bush enough to pull a trip wire and detonate a nearby mine. One cannot rely on mechanically activating old mines (or even new ones) to neutralise them. Many mines were laid by untrained personnel or civilians who had little idea how to lay them correctly, or were buried them too deep to stop more organised forces finding them with metal detectors. Hitting a mine may simply dislodge dirt which allows the mine to detonate the next time a person steps on it. Deeper mines may not detonate when the ground is hard, but later rain may soften the ground to the point where even a child's footstep will set them off. MinefieldsFor an excellent review of what mine clearance is really all about, read Colin King's paper "Mine Clearance in the Real World" [King 1997]. It is more helpful to think of areas of land which are suspected to be mined rather than "minefields" which may give the impression of mines laid in neat rows at regular intervals. Mined areas are often only found as a result of accidents to people or animals. A large area around the accident location is then declared as "probably mined". A "typical" minefield is hard to find. The pages linked to the top of this page illustrates minefields in several countries and help to show how mines have been laid in every conceivable place in every type of environment. Often mines have been used as a defensive measure and are laid in large numbers in a concentrated area. Elsewhere just a single mine may have been laid in a highly visible spot to create the impression that a whole area has been mined. Many minefields are littered with unexploded shells, rockets or mortar rounds, often just below the surface lying unnoticed. Where there has been fighting, there will also be millions of small metal fragments left behind. And everywhere there will be the rubbish left behind by soldiers and civilian occupants alike. In come climates (eg Cambodia under construction) thick scrub may have grown up in former fields and rice paddies. The vegetation has to be completely removed by hand before metal detectors can be used, and this consumes as much or more effort than clearing the mines. In open country or river beds, storms or floods may have carried mines far from their original locations or have buried them under layers of soil and debris. Mines placed on, in, or near buildings may lie deep under fallen rubble, with yet more mines laid on top. Some mines may have been set up as booby traps, detonating (for example) when something of apparent value is picked up. Irrigation canals which had mines laid on the sides and bottom may have been deliberately filled in with bulldozers, burying the mines under a metre or more of soil. Current demining methodsBefore demining can start, surveys are needed to produce detailed maps of minefields to be cleared. The survey team may use specially trained dogs to narrow down the limits of a mined area, and normally verifies a 1 or 2 metre wide "safe lane" around each minefield (using the same demining method as below) to define the minefield which may be surrounded with unknown land or other minefields. Typical minefields are 100 - 200 metres across and 0.1 - 10 Hectares in area. The manual clearance method is still the only one which is reliable enough to guarantee the 99.6% clearance requirement needed for resettlement of displaced civilians. With properly trained and supervised deminers wearing modest protective clothing, it is also relatively safe. In Afghanistan, a team of 30 deminers is assigned to clear each minefield. Two man clearance parties work on clearing parallel lanes, 1 metre wide, across the minefield with each lane about 25 metres from the next (considered to be a safe distance) [UNOCHA 96]. The main tools are:
One must not forget the essential human skills deminers need. With experience and training, their eyes reveal vital cues such as slight depressions in the ground caused by settling after mines were buried, their ears can distinguish different sounds from the metal detector, and their hands develop a feel for different buried objects. The principal limitation of this method is the time needed to investigate the many suspect metallic objects found in minefields. Analysis of statistics from 2500 Afghan minefields (Trevelyan 1997b) reveals that deminers typically find 1 to 1000 suspect objects for every 100 square metres, and clear 3 to 50 square metres per hour. On average for a 30 man team, between 1 and 15 hours pass between finding each mine or unexploded ordnance meaning that an individual deminer may work for months without finding a mine. Boredom and fatigue are key factors. Further ReadingWe have detailed reports on several countries which can be downloaded as PDF files (where links are provided below). These include:
Some countries have detailed web sites with more information than we can provide here. (see International Links)
References and Useful ReadingBlagden, P. M. (1997). Evolution of Mine Clerance Operations since 1991. SusDem97: International Workshop on Sustainable Humanitarian Demining, Zagreb, October, pp S1.1-6. EUREL (1996) Proceedings of EUREL International Conference on the Detection of Abandoned Landmines, IEE Conference Publication 431, London, UK. Focsaneaunu, G. (1997). Mechanical Clearance: A Long Overdue Solution. SusDem97: International Workshop on Sustainable Humanitarian Demining, Zagreb, October, pp S4.1-7. King, C. (1996). Janes Mines and Mine Clearance Techniques, King, C (Ed) Coulsdon (163 Brighton Rd, Coulsdon, Surrey CR5 2NH, UK) Jane's Information Group. King, C. (1997) Mine Clearance in the Real World. SusDem97: International Workshop on Sustainable Humanitarian Demining, Zagreb, October, pp S2.1-8. Jefferson (1997). Mines, Damn Lies and Statistics, Manchester Guardian, September 1997 (available from http://www.mech.uwa.edu.au/jpt/demining/lies.html). Joynt, V. (1997). MECHEM Experience in South Africa. SusDem97: International Workshop on Sustainable Humanitarian Demining, Zagreb, October, pp S3.31-35. Nicoud, J .D. (1995) Proceedings of Workshop on Anti-personnel Mine Detection and Removal WAPM '95, Swiss Federal Institute of Technology Microprocessors and Interfaces Laboratory (EPFL-LAMI), Lausanne, Switzerland. Nicoud, J-D. (1997) Vehicles and Robots for Humanitarian Demining, Industrial Robot Vol 24, No. 2, pp 164-168 . Red Cross (1995) Landmines must be stopped: Chapter VI Mine Clearance. Special Brochure, International Committee of Red Cross, Geneva, Switzerland. Trevelyan, J. P. (1996c) 'A suspended device for humanitarian demining.' (EUREL, 1996), pp.42-45. Trevelyan, J. P. (1997a) Robots and Landmines, Industrial Robot Vol 24, No. 2, pp 114-125. Trevelyan, J. (1997b). Modelling minefield clearance statistics. Technical Report, Department of Mechanical and Materials Engineering, University of Western Australia. Trevelyan, J. P. (1997c). Better tools for deminers SusDem97: International Workshop on Sustainable Humanitarian Demining, Zagreb, Croatia, October, pp S6.1-12. UNOCHA (1996) Notes on interviews with UN Office for Coordinating Humanitarian Aid to Afghanistan (UNOCHA), Islamabad. (Available from author).
|
