A minimum metal mine is a

land mine A land mine is an explosive device concealed under or 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. Such a device is typically detonated automati ...

that is designed to use the smallest amount of metal possible in its construction. Typically, the only metal components are located inside the

fuze In military munitions, a fuze (sometimes fuse) is the part of the device that initiates function. In some applications, such as torpedoes, a fuze may be identified by function as the exploder. The relative complexity of even the earliest fuze d ...

mechanism which triggers detonation. Both minimum metal

anti-tank Anti-tank warfare originated from the need to develop technology and tactics to destroy tanks during World War I. Since the Triple Entente deployed the first tanks in 1916, the German Empire developed the first anti-tank weapons. The first deve ...

and

anti-personnel mine Anti-personnel mines are a form of mine designed for use against humans, as opposed to anti-tank mines, which are designed for use against vehicles. Anti-personnel mines may be classified into blast mines or fragmentation mines; the latter may ...

s exist. Some designs contain virtually no metal at all, e.g., less than a

gram The gram (originally gramme; SI unit symbol g) is a Physical unit, unit of mass in the International System of Units (SI) equal to one one thousandth of a kilogram. Originally defined as of 1795 as "the absolute weight of a volume of pure wate ...

. This is achieved by encasing the explosive charge in a

plastic Plastics are a wide range of synthetic or semi-synthetic materials that use polymers as a main ingredient. Their plasticity makes it possible for plastics to be moulded, extruded or pressed into solid objects of various shapes. This adaptab ...

wood Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin th ...

en, or

glass Glass is a non-crystalline, often transparent, amorphous solid that has widespread practical, technological, and decorative use in, for example, window panes, tableware, and optics. Glass is most often formed by rapid cooling (quenching) of ...

body, with metallic components limited to the few small parts in the

which can not easily be made from other materials, such as the spring, striker tip, and

shear pin {{unreferenced, date=September 2018 A shear pin is a mechanical detail designed to allow a specific outcome to occur once a predetermined force is applied. It can either function as a safeguard designed to break to protect other parts, or as a con ...

. 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 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 contra ...

organizations and major militaries, making minimum metal mines especially pernicious where they are encountered.

Examples

Early examples included the

German German(s) may refer to: * Germany (of or related to) **Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Ger ...

Glasmine 43 The Glasmine 43 was an anti-personnel mine with a glass body used by the Nazi Germany during World War II. This mine was an early form of minimum metal mine, designed with the minimum amount of metal to reduce the likelihood of detection by the Po ...

Schu-mine 42 The Schü-mine 42 (''Schützenmine 42'', "rifleman's mine model of 1942"), was a German anti-personnel mine used during the Second World War. It consisted of a simple wooden box with a hinged lid containing a block of cast TNT and a ZZ-42 type det ...

and Topfmine used during

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

. 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 Serbia (, ; Serbian language, Serbian: , , ), officially the Republic of Serbia (Serbian language, Serbian: , , ), is a landlocked country in Southeast Europe, Southeastern and Central Europe, situated at the crossroads of the Pannonian Bas ...

, no metal) and the anti-personnel mines PRB M-409 (Belgium, less than 1g) and the

PMA-2 The Pressurized Mating Adapter (PMA) is a class of spacecraft adapters that convert the Common Berthing Mechanism (CBM) used on the US Orbital Segment to APAS-95 docking ports. There are three PMAs located on the International Space Station (IS ...

PMA-3 The Pressurized Mating Adapter (PMA) is a class of spacecraft adapters that convert the Common Berthing Mechanism (CBM) used on the US Orbital Segment to APAS-95 docking ports. There are three PMAs located on the International Space Station (IS ...

Serbia, (approx 1g non-magnetic) and

VS-50 VS-50 (suborbital rocket VS-50) is a joint development of sounding rocket from the Institute of Aeronautics and Space (IAE) and German Aerospace Center (DLR). Characteristics It is a suborbital vehicle that uses solid fuel, having two stages: ...

(Italy). Since the 1970s and until 1993 (when the country enacted a national landmines manufacturing ban, four years before signing the

Ottawa Treaty The Convention on the Prohibition of the Use, Stockpiling, Production and Transfer of Anti-Personnel Mines and on their Destruction of 1997, known informally as the Ottawa Treaty, the Anti-Personnel Mine Ban Convention, or often simply the Mine ...

) 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 Valsella Meccanotecnica SpA (also known as Valsella) was one of Italy's largest manufacturers of land mines. The Company's headquarters initially were in Montichiari. It had two production plants in Castenedolo near Brescia, Italy. The three com ...

SpA'' manufactured the

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.

Non-metallic mines

Though rare, a few land mine designs (both anti-tank and anti-personnel) contain no metal whatsoever. 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

which comprises a glass or plastic

vial A vial (also known as a phial or flacon) is a small glass or plastic vessel or bottle, often used to store medication as liquids, powders or capsules. They can also be used as scientific sample vessels; for instance, in autosampler devices i ...

containing a mixture of friction-sensitive

pyrotechnic Pyrotechnics is the science and craft of creating such things as fireworks, safety matches, oxygen candles, explosive bolts and other fasteners, parts of automotive airbags, as well as gas-pressure blasting in mining, quarrying, and demolition. ...

composition and glass powder. Downward force on the pressure plate overcomes the breaking strain of a plastic

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 A Belleville washer, also known as a coned-disc spring, conical spring washer, disc spring, Belleville spring or cupped spring washer, is a conical shell which can be loaded along its axis either statically or dynamically. A Belleville washer is ...

which flips downwards, stabbing a non-metallic tapered pin (sometimes made from a

glass ceramic Glass-ceramics are polycrystalline materials produced through controlled crystallization of base glass, producing a fine uniform dispersion of crystals throughout the bulk material. Crystallization is accomplished by subjecting suitable glasses to ...

) 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 A detonator, frequently a blasting cap, is a device used to trigger an explosive device. Detonators can be chemically, mechanically, or electrically initiated, the last two being the most common. The commercial use of explosives uses electri ...

and initiates the adjacent

booster Booster may refer to: Amusement rides * Booster (Fabbri ride), a pendulum ride * Booster (HUSS ride), an evolution of the Breakdance ride * Booster (KMG ride), a pendulum ride Arts, entertainment, and media Fictional characters * Booster, a cha ...

which in turn

detonate Detonation () is a type of combustion involving a supersonic exothermic front accelerating through a medium that eventually drives a shock front propagating directly in front of it. Detonations propagate supersonically through shock waves with s ...

s the main explosive filling.

References

{{Reflist Land mines

Examples

Non-metallic mines

See also

References