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The The role role of of electronics electronics in in MINE ACHTUNG! CLEARING In many parts of the world there is a vast problem with mines. In some cases these have been in place since World War I – yet they are still lethal. Huge numbers of civilians are still being killed or maimed by mines, years after hostilities have ceased. In this article, we investigate the role of electronics in mine clearing and discuss the many different types of mines which have to be dealt with. By BOB YOUNG W A second more sinister reason takes Australian veterans of the Korean hen dealing with this subinto account the fact that the sight of War can tell chilling stories of standing ject we enter into one of the maimed men can be quite demoralisin the face of Chinese human wave most ghastly fields of human ing for their friends and other soldiers. attacks, where it was virtually imposendeavour imaginable. Just read the sible to fire their guns fast enough to two accounts in the breakout panels However, in defence of military slow or stem the onslaught. A mineif you need any proof – and these “Chyeng was fetching field between such an enemy are about civilians! the cow from our field wh en adds greatly to the firepower The laying of vast fields of he stepped on a mine,” explained his father, Nyeng, in of a defending force, as the anti-personnel mines with the hospital with him. “We did not know there was any following descriptions of express purpose of maiming sol- danger there. I ran into the field to rescue him, but then mines clearly indicate. diers rather than killing them is I stepped on a second mine and lost my leg. I am a quite diabolical, as the following widower with eight other children. But in virtually every I am very fearful for all my children as I have no quote will illustrate quite clearly; case, the military forces money and now I canno t “Research has shown that it is work the land.” have callously walked away better to disable the enemy than from the battlefield and left to kill him” (Advertisement for their silent sentinels to Pakistani mines.) continue their grisly work thinking, there is another side to long after hostilities have The thinking is that injured men this story. ceased. require more resources than dead men. ilicon Chip hip 58  Silicon www.siliconchip.com.au As a result, minefield clearance is left mainly to civilian agencies to organise. This is largely because it is civilians who are suffering the agony of living with these lethal devices. With approximately 120 million mines scattered throughout 71 countries, few people in the western world have any idea of the immensity of the task facing the mine disposal teams. And nor do they have any real idea of the cost in terms of human suffering. There are up to 800 deaths and 1200 maimings each month – a tragedy of colossal proportions. danger of mine clearance can be gleaned from the following summary of information contained in the Norwegian People’s Aid landmine database at www.angola.npaid.org This is another very extensive landmine database, here discussing the Russian PMN blast mine. “The PMN has a circular bakelite body with a rubber plate on the top. The rubber plate is secured to the mine body by a thin metal band. The detonator/booster well is placed on the side of the mine body, opposite the fuse assembly well. The booster housing is made of plastic and the A plethora of mines detonator is fitted into the booster. To understand mine detection it is A plastic plug is screwed into the necessary to understand mine design detonator/booster well to close it. The Blast mines and construction. The designers of fuse assembly is screwed into the well these diabolical devices go to exThese are the most commonly on the opposite side of the detonator/ traordinary lengths to make them as booster well. The fuse is secured difficult to detect as is huwith a safety pin to prevent the t las o can vol r the Guazapa nea d die gs lin manly possible. Given the striker from moving forwards. sib ree “Th during pped on a mine planted human capacity to devise The fuse is delay armed. A thin d weekend when they ste ha ents re. Ironically, their par ways to kill people, they metal wire is attached to the back en the period of civil warfa ldr chi ys earlier. The have succeeded beyond returned to the area only a few da part of the striker enclosing a ee thr the m ars old. Parts fro ye ht eig d an six measure. lead strip.” r, fou were far as 30 metres from Land mines are composed children’s bodies were found as “When the safety pin is reof an endless array of diffi- the explosion site.” moved, the spring-loaded striker cult-to-detect materials such is released, causing the steel wire as plastic, Bakelite, phenolic to start cutting through the lead encountered type of land mine. The fibreglass, rubber, cardboard, delay strip. After the delay strip is Soviet PMN, also known as the Black neoprene and on occasions when the cut, the striker is allowed to move Widow, is one of the most widely designers really mean business, sheet forward until it stops on a step in used. Its large explosive content, 240g metal and steel. the actuating plunger. The mine is of TNT, is often fatal. It has probably now armed. The delay arming time is To detect, defuse and clear these killed and maimed more civilians from 15 to 37 minutes depending on grisly gadgets taxes human ingenuity than any other type of mine. It is the temperature. Pressure on the rubeven further. Sadly, the designers of pressure-activated, generally buried ber plate will depress the actuating the detection equipment to date have by hand and is deployed in vast plunger until the striker is released. fallen behind in the race, for the task numbers in Afghanistan, Cambodia, The striker fires the detonator and the has proven extraordinarily difficult. North Iraq/Kurdistan, Iran, Nicarabooster, which in turn detonates the Nor is it made any easier by the fact gua, Angola, Mozambique and many main charge.” that in many cases cleared fields are other countries. “The mine cannot be neutralised re-laid with a new stock of mines as because the forward motion of the soon as the clearance teams depart. PMN striker when the safety pin is reThe Mines Advisory Group has Some idea of the complexity and moved prevents the safety pin being documented more than 300 identified replaced. To disarm, hold the mine by the bakelite sides only. Unscrew and remove the detonating plug. Remove the detonator and booster from the mine. After disarming the mine, the striker can be removed by depressing the pressure plate to fire the striker out through the hole for the detonator plug.” “The Iraqi version of the PMN is named PMN HGE. It is black in colour This is the PMN landmine in cut-away and fully assembled. It has probably and is known to be extremely unstable killed more people than any other type of mine. Incidentally, we must apologise after years in the ground therefore no for the standard of photographs in this story: needless to say, mine manufacturattempt should be made to disarm ers are not all that forthcoming when asked for press photographs. Most of these this mine.” photos came as low-res pictures direct from the various websites mentioned. www.siliconchip.com.au land mines and even this is not a comprehensive list of the different devices. There is a very comprehensive landmine database at www.de-mining.brtrc.com/minesearch.asp This database includes all known mines, type, description, general information, characteristics, components, performance, analysts’ information, neutralisation and detecta-bility. This information is given so that people who have to live with these mines can clearly identify and deal correctly with the type of mine confronting them. However many mines have similar characteristics and a brief summary of common anti-personnel mines is given below: August 2001  59 TECHNICAL SPECIFICATIONS – PMN MINES Height........................................ 56mm Diameter.................................... 112mm Mine weight................................ 600 grams Explosive weight........................ 240 grams of TNT Casing material and colour......Brown body with black rubber plate or olive green body with green rubber plate. Fuse type................................... Integral cocked striker with delay arming. Sensitivity................................... 8-25kg pressure Detectability............................... Yes Anti-handling.............................. No Butterfly mines Millions of these small green mines were scattered from helicopters or launched from artillery throughout the war in Afghanistan. They became so familiar that children began to call them “green parrots”. One ‘wing’ contains liquid explosive. When pressure is applied, the explosive is forced into contact with the fuse. The amount of explosive is small but it can still take off a child’s hand. Fragmentation mines Developed in World War 2, these consist of a cast iron body on a wooden stake. Often known as ‘stake’ mines, they are triggered by trip-wire, causing jagged metal fragments to spray over a 100-metre radius. Anyone within 25 metres is likely to die. These were used extensively in Cambodia. Directional mines Often known as Claymore mines, these propel 700 steel balls forward in a 60° arc. They kill at up to 50 metres and maim at up to 100 metres. 70 percent remain lethal for over 20 years. This type of mine is often used in peri-meter defence. Usually activated by trip wire, some designs incorporate radio remote triggering. It requires no great imagination to envisage more exotic forms 60  Silicon Chip of triggering, such as passive infrared, sound, etc. Bounding mines Arguably one of the more sinister mine types, when triggered, the bounding mine leaps 45 centimetres in the air before shattering into more than 1000 metal splinters. The killing radius is at least 25 metres. A common example, the Italian Valmara 69 (illustrated above right), can be found all over northern Iraq. Detecting and clearing mines Minefield clearance is a tedious, costly and a very dangerous undertaking. By and large the work involves people locating and removing mines by hand and even “cleared” fields present their dangers. Thus we see a proliferation of research projects into automated mine clearance in order to remove the human dimension, but it is proving to be a difficult task indeed. Electronics plays a prominent part in experimental automated clearance systems and they are not meeting the challenge at all well. In the meantime, aid agencies are using older, well-proven methods such as “flail” machines (first used in WWII) and sniffer dogs. Although there are high investment costs related to mechanical mine clearance, the running costs are moderate compared with manual clearing. The distinct advantage of being able to clear areas faster than even large manual de-mining operations makes mechanical mine clearance cost effective. Used in conjunction with dogs and manual de-mining, rapid clearance rates can be achieved. For example Norwegian People’s Aid (NPA) purchased two refurbished Aardvark flail machines that had earlier seen service in the Gulf War, for Angola in October 1996. In July 1998, NPA increased its mechanical mine clearance capacity with two of the more powerful Hydrema flail machines. A third Aardvark machine was also donated to the organisation and arrived in Angola in October 1998. NPA is generally satisfied with its Aardvark and Hydrema machines. In Balombo, in Benguela province, the machines effectively identified the boundaries of a large minefield www.siliconchip.com.au and cleared base lines for the manual de-mining teams. This made it possible to deploy 150 de-miners in a targeted area at the same time. Without mechanical support the job would have taken 3-4 weeks and the boundaries of the minefield would still be unknown. In Ucua, a road which was de-mined mechanically would have taken 6-8 months to de-mine manually. Aadvaark in action In action the Aardvark is driven in reverse and a gyroscope is used to guide the driver, as it is sometimes at the GCS. This machine operates in vertical takeoff and landing modes, so there is no need for launch or recovery equipment. Modular in design, the Camcopter is transported to a field site via a light utility vehicle and can be carried into the field and set up by a single individual. It has integrated fail-safe mechanisms that reduce the Camcopter; a small unmanned helicopter fitted with sensors to locate and mark various mine types. The Camcopter’s primary payload is a dual-sensor gimbal system. It consists of an azimuth-over-elevation gimballed turret with integrated thermal imaging and monochrome television sensor modules. Groundstation impossible to see due to the dust from the flails and exploding mines. A strong crosswind is a great help in this job, as well as nerves of steel. It is not unknown for flail drivers to die in the line of duty. For the flail concept to be successful ground conditions have to be suitable. Flails can work well in areas with vegetation and high grass but high vegetation causes the loss of chains and reduction of the clearance speed. By now the reader will have gained some appreciation of the complexity and danger involved in mine clearing. There is a great need for more effective methods of mine detection and clearance but developing these systems is proving to be very difficult indeed. To illustrate just how difficult, the following is a summary of several experimental systems. This list is by no means exhaustive but serves to demonstrate the complexity of the task facing engineers designing these systems. Camcopter Perhaps the most novel idea is the www.siliconchip.com.au The Ground Control Station allows operators to program flights and monitor the Camcopter throughout the mission. Aimed at providing an aerial platform to be used for identification, detection, digital mapping and marking, and mission planning of mines and minefields, the Camcopter is a remotely controlled, fully autonomous aerial platform for use in locating and detecting individual mines and minefields. It is designed to carry equipment that can be used for data gathering, minefield mapping and de-mining mission planning. The Camcopter system consists of the Camcopter aerial platform, currently configured with a dual sensor gimbal assembly consisting of a CCD camera and infrared sensor, a dedicated Ground Control Station (GCS), a Flight Control Unit and a Sensor Control Unit. The Camcopter can be operated manually or automatically by programming preselected routes or way-points risk of injury or inadvertent damage and is simple to operate. Performance During testing, the Camcopter perfor-med at cruising speeds up to 90km/h and altitudes up to 1700 meters. With ideal conditions, the Camcopter may be operated within a 10km radius of a remote operator. The dual-sensor gimbal system, with its InSb-based 256 x 256 thermal imager and monochrome CCD camera, demonstrated the ability to locate mine-like objects. These objects were digitally marked using the on-board DGPS. The video tapes produced can be used for de-mining mission planning in previously unmapped areas. Hopefully the digital map could be used to determine the size and location of new mine-fields as well as individual mines when the system is fully developed. The limitations are that Camcopter must fly above the tree-line of heavily Camcopter Aerial Platform: vegetated areas and Power Plant: .......11kW (14.8 hp) two-stroke engine urban environments Cruise Speed: .............................. 90km/h (56 mph) can be difficult to fly Mission Radius: ................ 10km (6 miles) standard in because line-of-sight Data Link: ............................. S-Band, bi-directional communication is reVideo Link: ................................. C-Band (downlink) quired. Tracking: ..................... Fully-autonomous, remotely Navigation: ................ INS-based and DGPS-based Mini flail tank Climb Rate: ...........................300m/min (990 ft/min) The Mini-Flail is a Hover Ceiling: ..............1700m (weather permitting) remotely controlled Length: ......................................... 2500mm (98.43") utility vehicle that Main Rotor Diameter: ................ 3020mm (118.76") clears AP mines from Payload: ................................... Up to 25kg (55 lbs.) off-road areas that are August 2001  61 not accessible to large-area mine clearers. The Mini-Flail system uses chains attached to a spinning rotor to beat the ground and will detonate most AP mines. The Mini-Flail is effective against bounding, tripwire-fused and simple pressure-activated AP mines. found most AT mines but had difficulty identifying AP mines and proved very complicated to operate. Vehicle Mounted Mine Detector (VMMD) Completed Detection Projects Much of this work, as the reader can quite easily sense, is purely experimental or under development. The following section contains descriptions of completed detection projects and a brief description of the outcome from testing. Additional results are documented in the FY1995 test report, Countermine Technologies for Humanitarian Demining, Test Results Report, December 19, 1995, available from the Defence Technical Information Centre (DTIC A310061). Vehicle Mounted Detection System (VMDS) The VMDS concept is based on a commercial skid steer chassis modified to incorporate a remote control capability. The VMDS sensor package consists of a 2-metre wide Schiebel metal detection array, a Thermal-Neutron Analysis (TNA) sensor and an infrared sensor. The 2-metre array detects metal objects in the vehicle’s path, while the TNA indicates those targets that contain explosives. In testing, the 2-metre array performed extremely well. The TNA The VMMD is also a small modified utility vehicle. The VMMD sensor package consists of ground penetrating radar, infrared and ultraviolet cameras. The VMMD did well in detecting AT mines but had difficulty identifying AP mines and proved very complicated to operate. Ground Based Quality Assurance The Ground Based QA prototype was an assembly of four cameras (3-5 micron and 8-12 micron IR, UV and normal video). The concept was to feed the signals from all four cameras which are aimed at the same spot, to a computer software program that would analyse the images and use an automatic target recognition (ATR) algorithm to mark suspected mine locations on the operator’s screen. Although the system showed potential, the prototype did not consistently discriminate mines from clutter. Humanitarian Innovative Mine Sensor (HIMS). In 1997, the Humanitarian De-min62  Silicon Chip ing Program investigated the use of polarised IR cameras to detect mines. The advantages of polarimetric imagery over conventional radiometric IR for detection of mines were not demonstrated. K9 program In 1995, the Humanitarian De-mining R&D Program demonstrated the effectiveness of using dogs for mine detection. The program evaluated two systems, free leash, which used a dog and handler in a mined area and the Mechem Explosive and Drug Detection System (MEDDS), which collects air samples in suspected mined areas for dogs to smell at a remote location. The program also investigated what effects burned areas and explosive material scattered on the ground had on the dogs’ ability to detect buried mines. Both dog programs performed well. In fact, after a great deal of research, sniffer dogs are still more effective overall than electronic methods for mine detection. So there you have it, a brief excursion into one of the less edifying SC aspects of human creativity. www.siliconchip.com.au