The identification and removal of landmines is a mandatory condition for affected areas to return to a normal life and for people to come back to their homes and attend the humanitarian programs. Because these operations are often dangerous for the teams that deal with demining and for local people as well, if some mines remain undetected, researchers have been trying to find new methods of landmine detection and removal. New technologies are applied in order to bring more safety and efficiency to the demining process.
New Methods Involving Advanced Technologies
The use of nuclear reactions, sound waves, or high frequency signals for the detection of landmines promises to make the detection procedure more effective and less risky for the people involved. As a result, not only the demining procedure will be more accurate, but the personnel of the demining teams will be safer too. Here are some new methods:
- Ground penetrating radar – Unlike conventional metal detectors relying on electromagnetic signals at frequencies between 10 and 100 kHz, a GPR (Ground Penetrating Radar) uses frequencies of the order of 1 GHz. Wooden or plastic mine bodies cannot be detected with conventional detectors because they do not have metal parts. A GPR is sensitive to non-metallic parts as well. However, they could be affected by objects like tree roots or stones. Changes in the soil moisture also can make it difficult to distinguish mines on GPR images.
- Dual sensor – A combination of a conventional metal detector sensor and a GPR may provide a single instrument that can detect both metal and non-metal mines.
- Acoustic detection – Landmines can also be detected by directing a sound wave at the area that has to be demined. This wave will make the mine to vibrate and its vibrations can be captured by a laser, by means of a Doppler shift technique.
- Nuclear detection – The use of neutrons can result in two techniques that can be helpful in detecting landmines. The first method relies on the rich content in nitrogen that all mines have. By subjecting the landmine to thermal neutrons and looking for the characteristic gamma emission, the source of nitrogen can be identified. An alternative solution consists in irradiating the soil with fast neutrons and measuring the flux of the thermal neutrons that come back. This technique relies on the high concentration of hydrogen, known to be a very effective moderator for the flux of neutrons.
When relative peace is installed, mine removal is called demining. This process is time-intensive and aims to locate all the mines, in order to return the area to normal use. Such processes have to be exhaustive. If only a few mines remain undetected, the number of civilian mine casualties could increase as soon as the local people return to the area, believing that it is safe.
In certain situations, it is necessary to clear landmines as a condition before implementing other humanitarian programs. Large efforts have been made internationally to elaborate new technologies meant to help humanitarian demining.
Some Demining Methods
Apart from mechanical clearing that uses armored vehicles to detonate landmines, other methods are available to demining teams that activate in areas that were or are subject to civil wars, interstate wars, or terrorist activity.
Manual detection of landmines and their disarmament is a slow process, at the same time expensive and dangerous. However, demining can be even safer than the construction work, when procedures are rigorously followed. Recent research and new technologies are supposed to provide effective alternatives.
Here are some procedures that demining teams apply:
- Manual detection with metal detectors – Metal detectors have been invented by a Polish officer. The demining procedure begins with scanning the area using metal detectors. These devices are sensitive and can pick up most landmines. There are mines, called minimum metal mines, which are made with about one gram of metal, in order to make them difficult to detect. Other mines have no metal at all, but they are rare. The areas where the detectors find metal are carefully inspected to see if mines are present. The probing continues until the object detected by the device is found.
- Detection using dogs – If dogs are well trained, they can sniff out substances with explosive potential, such as TNT, and, consequently, they can detect the presence of landmines. Dogs are used in certain countries.
- Detection using rats – Giant pouched rats are animals that can be trained to sniff out TNT and other chemicals found in landmines. African countries are using such rats because they originate in East Africa and can be easily found and trained. The advantage of using such animals is that they have a far lower mass than humans, so they do not usually to set off smaller mines that are meant to kill or injure people, not even when they cross over them.
Specially designed machines combine two operations – detection and removal of mines – into one. Such machines were previously used in mine clearance and in demining as well, but, now, they are only used for demining. They are used to check the land that is already decontaminated and may provide an additional level of security in an area that has already been cleared through other methods.
These machines consist of special vehicles that are driven through minefields and deliberately detonate the mines they drive over. Their construction is solid enough to withstand eventual explosions with only little damage. Some of these machines are operated directly, but have special protection for the driver, while others are controlled remotely and do not need a driver.
Types of Machines Used in Demining
Several types of machines are used for demining purposes, depending on the geographical area, but a few types are almost standard:
- Mine rollers and flails – The rollers originate in World War I, while the flails are known from World War II. Both types are still in use. Neither of them is completely reliable, and they often leave undetonated mines in the field. For this reason, a recheck of the minefield using a different method is always necessary. The effectiveness of mine flails can reach 100% only in ideal conditions, but their clearance rates do not exceed 50-60%. The United Nations Standard for humanitarian demining is, however, much higher: 99.6%.
- Mine plows –These are devices positioned in front of tanks, which excavate the ground. They expose the mines or turn them upside down, lessening significantly their effect when they explode.
- Combined machines – They represent a combination of the previous types on the same vehicle.
- Modified bulldozers – Log-armed bulldozers are modified for demining purposes and are used in several countries. They can remove vegetation before starting the demining process and are capable of withstanding both antitank and antipersonnel landmines. With their long arms, these machines can reduce eventual damage to the main vehicle body, and especially to the cabin of the operator. In fact, the operator is also protected from being hurt by directional mines by a three inch thick bulletproof glass.
Many armies have recently developed armored vehicles for demining, especially armored bulldozers. These machines are controlled by remote commands. This way, the risk for human operators is eliminated. It is important to preserve human lives, and modern demining machines are designed to meet this requirement.
The detection of landmines is extremely important for the clearing of areas affected by war or terrorism. Minesweeping uses a series of methods to identify the location of landmines. Among these methods, biological means of mine detection have a distinct place. Recent research promotes new ways of detection to the attention of the scientific world. Insects, little mammals, plants, and even bacteria can be used to detect landmines, according to the researchers.
Some Living Organisms Prone to Be Used in Demining
- Mammals – The Gambian giant pouched rat has the required smell sensitivity and can be trained with food-reward incentives. This animal, indigenous to the East of the African continent, is too small to set off a mine and is a reliable solution for African countries where conflicts are frequent. Recent experiments that used electro-guided rats demonstrate that demining could be accomplished one day by “ratbots” in areas where humans cannot penetrate. Dolphins and sea lions are also trained to detect sea mines inside the US Navy Marine Mammal Program.
- Honey bees are able, with minimal training, to detect landmines with a great accuracy and clearance rate, better than rats or dogs, according to studies performed by the University of Montana.
- Plants – The mustard species Arabidopsis thaliana is one of the plants most studied for their ability of changing color in contact with chemical agents. Based on a combination of genetic manipulation and natural mutations, the Danish researchers have created plants that change their color as a response to nitrous oxide, a substance leaking from landmines and other explosive devices. Such plants would help demining by identifying the presence of mines through changes in their color. They could be planted by people who pass through demined paths in minefields, or from aircrafts.
- Bacteria – Special organisms, known as bioreporters have been genetically engineered to become fluorescent under UV light when TNT was present. By spraying such bacteria over simulated minefields, the scientists have tested their capacity of detecting mines. This method could help demining personnel to cover hundreds of acres in only a few hours, which would provide a much faster solution than what is currently available. It could be used on terrains of a wide variety. Unfortunately, these bacteria are not capable of detecting RDX, which is another common explosive. As well, bacteria would not be visible in desert-like conditions or on munitions that are not corroded.