Science Fair Project Encyclopedia
A landmine is a type of mine which is placed onto or into the ground and explodes when triggered by a vehicle or person. Landmines are used to secure disputed borders and to restrict enemy movement in times of war. Because of this, and also because not all types are designed to be buried in the ground, and to avoid using the word landmine, they are sometimes called area denial munitions, serving a tactical purpose similar to barbed wire or concrete dragon's teeth vehicle barriers — that is, channeling the movement of the attacking troops in ways that permit the defenders to ambush them more easily, or attack them with artillery bombardments planned in advance to cover a certain area.
From a military perspective, landmines serve as force multipliers, allowing an organized force to overcome a larger enemy.
Following the lead of Canada, the majority of the world's countries (144 to date) have made the use and possession of anti-personnel landmines by its military forces illegal. The only two western democracies that have not banned anti-personnel landmines are the United States and Finland. Some other countries like China, Russia and North Korea also continue to use them.
A landmine can be triggered by a number of things including pressure, movement, sound, magnetism and vibration. Anti-personnel mines commonly use the pressure of a person's foot as a trigger, but tripwires are also frequently employed. Most modern anti-vehicle mines use a magnetic trigger, to enable it to detonate even if the tyres or tracks did not touch it. Advanced mines are able to sense the difference between friendly and enemy types of vehicles by way of a built-in signature catalog. This will theoretically enable friendly forces to use the mined area while denying the enemy access.
Many mines combine the main trigger with a touch or tilt trigger, to prevent enemy engineers from defusing it. Also, landmine designs tend to use as little metal as possible to make searching with a metal detector more difficult. Also, landmines made mostly of plastic are very inexpensive.
The Chinese Type 72, which is according to some sources the world's most popular landmine, costs only US$3 apiece if bought in large quantities. It is mostly plastic, only about the size of the palm of a man's hand, and contains just enough TNT to blow off a foot.
An antipersonnel mine that is used within a building or with some sort of psychological bait is called a booby trap. The term booby trap also implies that the device is improvised, perhaps from an artillery shell or a grenade, rather than manufactured for this specific purpose.
Mines used by the U.S. Army and many other forces are designed to self-destruct after a period of weeks or months to reduce the likelihood of civilian casualties at the conflict's end. However, these self-destruct mechanisms are not absolutely reliable, and most landmines laid historically are not equipped in this manner.
Minefields may be laid by several means. Mine-scattering shells may be fired by artillery from a distance of several tens of kilometers; mines may be ejected from cruise missiles, or dropped from helicopters or airplanes. Armored fighting vehicles equipped to lay mines have also been built. The preferred way is to have trained personnel bury the mines, since this will make the mines practically invisible and reduce the number of mines needed to deny the enemy an area.
Often anti-tank minefields are scattered with anti-personnel mines to make clearing them manually more time-consuming; and anti-personnel minefields are scattered with anti-tank mines to prevent using armored vehicles to clear them quickly. Some anti-tank mine types are also able to be triggered by infantry, giving them a dual purpose even though their main and official intention is to work as anti-tank weapons.
Detecting and removing landmines
While placing and arming landmines is relatively inexpensive and simple, the reverse of detecting and removing them is typically expensive, slow and dangerous.
Various means to detect landmines include:
- Carefully searching suspected or known minefields areas for mines. Often this is done by crawling slowly into the field, inserting a probe (anything from a knife to a stick) into the soil to find hard objects. When walking in mined areas, mine-clearing personnel will wear large, pillow-like pads strapped under their feet, to spread their weight and dull the impact of their footsteps, as very slight disturbances of the ground can tip off old, unstable, or intentionally sensitive mine triggers.
- Using metal detectors to sweep a suspected minefield. However, the detectors may not easily differentiate various types of metal objects, which slows the search.
- Using animals like dogs that can sniff out explosive chemicals like TNT in landmines. 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.
- Sowing genetically engineered flower seeds over suspected minefields from the air. The flowers bloom in distinctive colors when there are explosives nearby in the soil.
Methods for removing landmines include:
- Manually disarming them.
- Carpeting the suspected minefield with an artillery barrage.
- 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 armored 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.
- 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.
Efforts to ban anti-personnel mines
Anti-personnel landmines or APLs are widely considered to be ethically problematic weapons because their victims are commonly civilians, who are often killed or maimed long after a war has ended. According to anti-landmine campaigners, in Cambodia alone mines have resulted in 35,000 amputees after the cessation of hostilities. Removal of landmines is dangerous, slow and costly; however, some countries maintain that landmines are necessary to protect their soldiers in times of war.
Signatories of the Ottawa Treaty which came into force in 1999 agreed that they would not use, develop, manufacture, stockpile or trade in anti-personnel landmines. Existing stocks must be destroyed within four years of signing the treaty. There were originally 122 signatories in 1997, and as of February 2004, it has now been signed 152 countries, of which 144 have ratified it.
As of February 2004, 42 countries have not agreed to it. The biggest of these are the People's Republic of China, India, the USA and the Russian Federation. The treaty was the result of the International Campaign to Ban Landmines, launched in 1992, whose web site at http://www.icbl.org has the treaty text and the complete list of signatories. The campaign won the Nobel peace prize in 1997 for its efforts; the prize was shared with its leader, Jody Williams.
According to the ICBL report for August 2004, 80 countries declared stockpiles totalling 48 million landmines, of which 37.5 million have been destroyed so far and 65 countries have completed their destruction. Another 51 countries declared that they did not possess stockpiles to destroy. Nine countries signed the treaty in the year to August 2004. 
There is a clause in the treaty, Article 3, which permits countries to retain landmines for use in training or development of countermeasures. 64 countries have taken this option. In February 2004, the number of mines retained varied from 93 for Mauritius, 1783 for the United Kingdom, around 4000 for France and Spain, 9,000 for Japan right up to as many as 69,200 for Turkmenistan. Other high levels are reported by Brazil (16,545), Sweden (16,015), Algeria (15,030), and Bangladesh (15,000). In total 289,000 mines have been declared as retained by various countries under Article 3. A further 23 countries have not declared a figure. 
As an alternative to an outright ban, 10 countries follow regulations that are contained in a 1996 amendment of Protocol II of the Convention on Conventional Weapons (CCW). The countries are China, Finland, India, Israel, Latvia, Morocco, Pakistan, South Korea, Sri Lanka, and the United States. 
The Ottawa Treaty does not include anti-tank mines, cluster bombs or claymore-type mines operated in command mode, but does cover victim-activated claymore-type mines, i.e. activated by tripwires etc. 
The ICBL has identified the following countries as manufacturing landmines as of August 2004. None are signatories of the Ottawa Treaty. 
- Cuba 
- Iraq (although production had presumably ceased since the invasion of 2003)
- Iran 
- India 
- Myanmar 
- Nepal 
- North Korea 
- Pakistan 
- Russian Federation 
- Singapore 
- Vietnam 
Of other states which are thought to have manufactured landmines recently:
- Turkey is now a signatory of the Ottawa Treaty 
- Serbia and Montenegro is now a signatory of the Ottawa Treaty 
- Egypt has unofficially stated that production ceased in 1988. 
- The United States has not manufactured antipersonnel mines since 1997, but a government statement in February 2004 stated that, “The United States will continue to develop non-persistent anti-personnel and anti-tank landmines.”
- South Korea has stated that no mines have been produced since 2000. 
- An official from China stated in September 2003 that production has ceased there, since they have an ample stockpile. 
- In March 2004, a Libyan official stated that the country has never produced antipersonnel mines, but is known to have laid landmines in the 1970s and 1980s 
- A United Nations Assessment Mission to Peru reported that production of landmines in the country ceased in January 1999. Peru was one of the original signatories and to the treaty came into force for them in March 1999. 
The Soviet Union had been accused of using specifically-designed mines looking like toys (to target children) in its conflict with Afghanistan. Some of the Soviet mines used were small, green, made from plastic and winged so that they could be deployed from planes, with the result that children often mistook them for toys, but others were allegedly manufactured of red and white plastic in the shape of toy trucks.
Unexploded bomblets from cluster bombs pose the same dangers as landmines. This is probably in some cases a design feature, intended to pin down the military force upon which they are dropped and discourage it from moving. Although they are not designed to be hidden, they may remain undetected for a long time due to soft soil or vegetation. Children could also mistake the bomblets for toys due to the bright colors commonly employed in the manufacture of cluster munitions to indicate they are "live" or explosive ordnance.
The current trend in design of cluster bombs is the use of smart munitions, such as those incorporated into the CBU97 used by the US Air Force and US Navy. The smart munitions are approximately the size of small artillery shells and have guidance circuitry allowing them to seek out and destroy armored vehicles, or self-destruct if they do not achieve target lock before reaching the ground. This innovation seems likely to reduce the humanitarian cost of using cluster bombs though the CBU97 and other weapons in its class, such as the Russian RBK500, are extremely expensive.
The basic concept appeared through out human history in various forms. In Europe in the early 18th century, often going by the French term fougasse, improvised landmines or booby traps were constructed in the form of bombs buried in shallow wells in the earth and covered with scrap metal and/or gravel to serve as shrapnel. The term is sometimes still used in the present day to describe such devices. The technique was used in several European wars of the 18th Century, the American Revolution, and the American Civil War. Some sources report that Zhuge Liang, of the kingdom of Shu of China, invented a landmine type device in the third century AD. Similar in concept to the modern landmine, small foot-sized holes dug in the ground with a sharpened spike, and then covered, were used by forces of ancient Rome. In the Middle Ages in Europe, small, 4-pronged spiked devices called caltrops or crows feet could be scattered on the ground.
The first modern mechanically fused high explosive antipersonnel landmines were created in Imperial Germany, circa 1912, and were copied and manufactured by all major participants in the First World War. In World War I, landmines were used notably at the start of the battle of Passchendale. Well before the war was over, the British were manufacturing landmines that contained poison gas instead of explosives. Poison gas landmines were manufactured at least until the 1980s in the Soviet Union and the United States was also known to have at least experimented with the concept in the 1950s.
Nuclear mines have also been developed, both landmines and naval mines. An example is the British Blue Peacock project.
The name itself probably comes from the skills used by miners in World War I in which tunnels were dug under the opposition forces, filled with explosives, and detonated. Some 45 tons of explosives were detonated at Spanbroekmolen on June 26, 1916, forming a crater some 430 feet (130 m) in diameter. Many such smaller mining operations were used to attack entrenched enemy emplacements.
- The International Committee of the Red Cross on Landmines
- The International Campaign to Ban Landmines
- Equipment for post-conflict demining
- The Tubular Bangalore Torpedo activates mines by blasting the tube after it has been pushed into the minefield.
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