A minimum metal mine is a land mine that is designed to use the smallest amount of metal possible in its construction. Typically, the only metal components are located inside the fuze mechanism which triggers detonation. [1] Both minimum metal anti-tank and anti-personnel mines exist. Some designs contain virtually no metal at all, e.g., less than a gram.
This is achieved by encasing the explosive charge in a plastic, wooden, or glass body, with metallic components limited to the few small parts in the fuze which can not easily be made from other materials, such as the spring, striker tip, and shear pin. [2] Minimum metal mines are extremely difficult to detect using conventional metal mine detectors and usually require modern techniques, such as robotic Multi Period Sensing (MPS) equipment, to identify, but it is still extremely difficult to find non-metallic mines. These techniques are usually restricted to well-funded international mine clearing organizations and major militaries, making minimum metal mines especially pernicious where they are encountered. [3]
Though rare, a few land mine designs (both anti-tank and anti-personnel) contain no metal whatsoever. [4] Such mines cannot be found using metal detectors because there is no metal to detect. Typically, 100% non-metallic landmines have a plastic case and a fuze which comprises a glass or plastic vial containing a mixture of friction-sensitive pyrotechnic composition and glass powder. Downward force on the pressure plate overcomes the breaking strain of a plastic shear pin which snaps, allowing the non-metallic firing pin assembly to move. The firing pin is pushed down through a flexible plastic forcing-cone, which abruptly releases it on the other side at much higher velocity. Concentrated pressure is thereby transferred directly onto the glass vial, crushing and fracturing it. Alternatively, when the shear pin breaks, pressure on the fuze is transferred onto a plastic belleville spring which flips downwards, stabbing a non-metallic tapered pin (sometimes made from a glass ceramic) through a thin plastic membrane covering the vial of friction-sensitive pyrotechnic mixture. Either way, this action causes a flash of flame that triggers the detonator and initiates the adjacent booster which in turn detonates the main explosive filling.
Early examples included the German Glasmine 43, Schu-mine 42 and Topfmine used during World War II. These designs were either difficult or impossible to find using 1940s metal detectors.
Many different types of minimum metal mines have been produced in various countries over the years. Relatively modern examples include the antitank mines M19 (United States, less than 3g of metal) and TMA-3 (Serbia, no metal) and the anti-personnel mines PRB M-409 (Belgium, less than 1g) and the PMA-2 or PMA-3 Serbia, (approx 1g non-magnetic) and VS-50 (Italy). Since the 1970s and until 1993 (when the country enacted a national landmines manufacturing ban, four years before signing the Ottawa Treaty) Italy became a world leader in the manufacture of minimum metal mines; the three main Italian landmine manufacturers were mostly producing minimum-metal mines by the early 1980s. Valsella Meccanotecnica SpA manufactured the VS-50 and VS-Mk2. Misar SpA produced the SB-81 and SB-33, and Tecnovar Italiana SpA produced the TS-50, TC/3.6 and TC/6 mines.
Article 4 of the 1996 Amended Protocol II to the Convention on Certain Conventional Weapons provides that “It is prohibited to use anti-personnel mines which are not detectable, as specified in paragraph 2 of the Technical Annex [5] .”
A land mine, or landmine, is an explosive weapon concealed under or camouflaged on the ground, and designed to destroy or disable enemy targets, ranging from combatants to vehicles and tanks, as they pass over or near it.
Type 72 Non-Metallic is a Chinese circular, plastic bodied landmine which is designed to damage or destroy a vehicle by blast effect.
Demining or mine clearance is the process of removing land mines from an area. In military operations, the object is to rapidly clear a path through a minefield, and this is often done with devices such as mine plows and blast waves. By contrast, the goal of humanitarian demining is to remove all of the landmines to a given depth and make the land safe for human use. Specially trained dogs are also used to narrow down the search and verify that an area is cleared. Mechanical devices such as flails and excavators are sometimes used to clear mines.
The M14 mine "Toepopper" is a small anti-personnel land mine first deployed by the United States circa 1955. The M14 mechanism uses a belleville spring to flip a firing pin downwards into a stab detonator when pressure is applied. Once deployed, the M14 is very difficult to detect because it is a minimum metal mine, i.e. most of its components are plastic. Because of this, the design was later modified to ease mine clearance with the addition of a steel washer, glued onto the base of the mine.
The M16 mine is a United States-made bounding anti-personnel mine. It was based on captured plans of the World War II era German S-mine and has similar performance. The mine consists of a cast iron body in a thin steel sleeve. A central fuze well on the top of the mine is normally fitted with a pronged M605 pressure/tension (tripwire) fuze. Sufficient pressure on the prongs or tension on an attached tripwire causes the release of a striker. The freed striker is forced into a percussion cap which ignites a short pyrotechnic delay. The purpose of this delay is to allow the victim to move off the top of the mine, to prevent its upward movement from being blocked. Once the delay has burned through, a 4.5-gram black powder charge is ignited, which launches the inner iron body of the mine up into the air. The charge also ignites a second pair of pyrotechnic delays.
An anti-personnel mine or anti-personnel landmine (APL) is a form of mine designed for use against humans, as opposed to an anti-tank mine, which target vehicles. APLs are classified into: blast mines and fragmentation mines; the latter may or may not be a bounding mine.
The PROM-1 is a Yugoslavian manufactured bounding anti-personnel mine. It consists of a cylindrical body with a pronged fuze inserted into the top of the mine. It is broadly similar in operation to the German S-mine.
The PMN series of blast anti-personnel mines were designed and manufactured in the Soviet Union. They are one of the most widely used and commonly found devices during demining operations. They are sometimes nicknamed "black widow" because of their dark casings.
The M15 mine is a large circular United States anti-tank blast mine, first deployed during the Korean War. Essentially, it is a larger version of the M6A2 anti-tank mine, which it replaced. Although the M15 has been superseded by the M19 mine, the U.S. retains large stocks of M15s because they are still regarded as reliable and effective weapons. When used against main battle tanks the M15 is primarily a "track-breaker" which creates mobility kills, but has a comparatively small likelihood of causing crew fatalities. However, when used against light vehicles such as APCs or unarmored vehicles such as trucks the damage it can inflict is much more severe.
The VS-50 is a circular plastic-cased anti-personnel blast mine that entered production in 1985. It was formerly made by the now-defunct Valsella Meccanotecnica SpA, an Italian high-tech defence company specialized in area denial systems. The company also the made the Valmara 69, and was one of the first to implement plastic construction for landmines. The VS-50's design is similar to that of the TS-50 and VS-MK2 mines. It is blast resistant and can be used in a minimum metal configuration. Though unlikely to kill, its explosive charge is quite sufficient to destroy the victim's foot, being capable of penetrating 5 mm of mild steel leaving an 80 mm-diameter hole.
The PRB M3 and PRB M3A1 are plastic cased minimum metal anti-tank blast mine produced by the Belgian company Poudreries Réunies de Belgique in the 1970s and 1980s. The mine is square with an olive drab body constructed from polythene with a webbing carrying handle on the side and an ammonia-free bakelite seating for the pressure plate to be screwed into. The fuze well is in the centre of the seating, with the pressure plate screwed into it after the fuze has been inserted. The cylindrical pressure plate consists of two plastic plates, one of which moves under the weight of a vehicle driving over the mine to transmit the force to the fuze, shearing pins which hold it in place.
An anti-handling device is an attachment to or an integral part of a landmine or other munition such as some fuze types found in general-purpose air-dropped bombs, cluster bombs and sea mines. It is designed to prevent tampering or disabling, or to target bomb disposal personnel. When the protected device is disturbed, it detonates, killing or injuring anyone within the blast area. There is a strong functional overlap of booby traps and anti-handling devices.
The Topfmines were a series of German circular minimum metal anti-tank blast mines that entered service with the German army in 1944, during the Second World War.
The Mle 1951 or MI AP ID 51 is a small circular French brown plastic cased minimum metal mine anti-personnel blast mine. The mine uses a pressure fuze that works by driving a firing pin through a friction sensitive compound. The mines safety is a small cap that sits over the pressure fuze and prevents it being pressed. The mine can be used with anti-handling devices.
The VAR/40, VAR/100 and VAR/100/SP are Italian anti-personnel blast landmines produced by the Tecnovar italiana S.p.A. company.
The TS-50 is a 90 mm (3.5 in) diameter circular Italian blast resistant minimum metal anti-personnel mine designed and produced by Valsella Meccanotecnica (Italy).
The PMA-3 is a Yugoslavian blast resistant minimum metal anti-personnel mine. It is circular, consisting of a plastic upper and lower half joined together by a rubber cover. A safety collar is normally wrapped around the outside of the mine, preventing the upper half of the mine tilting when in transit. Once deployed the safety collar is removed. Sufficient pressure on the top surface of the mine causes it to tilt. The tilting drives a pin through a friction sensitive pyrotechnic compound, which fires the detonator and then the main explosive charge.
The Pignone mod.43 were bakelite cased Italian anti-tank blast mines used during the Second World War in North Africa and Italy.
The Husky VMMD is a configurable counter-IED MRAP vehicle, developed by South African-based DCD Protected Mobility and American C-IED company Critical Solutions International. Designed for use in route clearance and de-mining operations, the Husky is equipped with technologies to help detect explosives and minimise blast damage.
The PMA-2 is a Yugoslavian blast antipersonnel mine. Sometimes referred to as the 'Pašteta', due to its superficial resemblance to a meat-pâté tin. The mine is constructed from dark green plastic, with a distinctive plunger which has six petals radiating from it.