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Gravel Mine
Gravel mines, also called Button mines, were small United States made air-dropped anti-personnel mines. They were used extensively during the Vietnam War as part of the McNamara Line. They were also used as a rapid-deployment area denial expedient, to provide a barrier during combat search and rescue (CSAR) operations between downed pilots or other endangered units and infantry threats. General information Components The mines consisted of a small green or brown camouflage fabric pouch filled with lead(II) azide and 30 grams of coarse ground glass between two sheets of plastic. No fuse was required because the explosive became shock-sensitive after dispersal, i.e. able to be detonated without a fuse on contact. The explosive lumps came in wedge or cubed shapes and their plasticizers evaporated after three to eight minutes exposure to air. To allow them to be handled and dropped from the air, the mines were phlegmatized with Freon 113, in which they were stored soaked. Once relea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 or may not be a bounding mine. The mines are often designed to injure, not kill, their victims to increase the logistical (mostly medical) support required by enemy forces that encounter them. Some types of anti-personnel mines can also damage the tracks on armoured vehicles or the tires of wheeled vehicles. The International Campaign to Ban Landmines has sought to ban mines culminating in the 1997 Ottawa Treaty, although this treaty has not yet been accepted by over 30 countries. Use Anti-personnel mines are used in a similar manner to anti-tank mines, in static "mine fields" along national borders or in defense of strategic positions as described in greater detail in the land mine article. What makes them different from most anti-ta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vietnam War
The Vietnam War (also known by #Names, other names) was a conflict in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. It was the second of the Indochina Wars and was officially fought between North Vietnam and South Vietnam. The north was supported by the Soviet Union, China, and other communist states, while the south was United States in the Vietnam War, supported by the United States and other anti-communism, anti-communist Free World Military Forces, allies. The war is widely considered to be a Cold War-era proxy war. It lasted almost 20 years, with direct U.S. involvement ending in 1973. The conflict also spilled over into neighboring states, exacerbating the Laotian Civil War and the Cambodian Civil War, which ended with all three countries becoming communist states by 1975. After the French 1954 Geneva Conference, military withdrawal from Indochina in 1954 – following their defeat in the First Indochina War – the Viet Minh to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
McNamara Line
The McNamara Line, an operational strategy employed by the United States in 1966–1968 during the Vietnam War, aimed to prevent infiltration of South Vietnam by NVA forces from North Vietnam and Laos. Physically, the McNamara Line ran across South Vietnam from Cửa Việt port to Route 9 and to the Laotian border along the Vietnamese Demilitarized Zone (DMZ) till Mường Phìn, Laos. The eastern part included fortified field segments, with Khe Sanh as linchpin, along with stretches where roads and trails were guarded by high-tech acoustic and heat-detecting sensors on the ground and interdicted from the air. Assorted types of mines, including so-called gravel mines, and troops at choke points backed sophisticated electronic surveillance. Named ''the barrier system'' by Robert McNamara (United States Secretary of Defense from 1961 to 1968), it was one of the key elements, along with gradual aerial bombing, of his war strategy in Vietnam. Barrier concept Various schemes ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Area Denial Weapon
An area denial weapon is a defensive device used to prevent an adversary from occupying or traversing an area of land, sea or air. The specific method used does not have to be totally effective in preventing passage (and sometimes is not) as long as it is sufficient to severely restrict, slow down, or endanger the opponent. Some area denial weapons pose long-lasting risks to anyone entering the area, specifically to civilians, and thus are often controversial. An area denial weapon can be part of an anti-access/area denial (A2/AD) strategy. Historical methods Anti-cavalry In medieval warfare, sharp and sturdy stakes were buried at the bottom of long lines of ditches, pointed end up diagonally, in order to prevent cavalry charges in a given area. Even if the stakes were spotted, soldiers would be forced to dismount and effectively give up their advantage as cavalry as well as becoming easier targets. The correct layout of these extensive lines of ditches and the quality control o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Camouflage
Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Examples include the leopard's spotted coat, the battledress of a modern soldier, and the leaf-mimic katydid's wings. A third approach, motion dazzle, confuses the observer with a conspicuous pattern, making the object visible but momentarily harder to locate, as well as making general aiming easier. The majority of camouflage methods aim for crypsis, often through a general resemblance to the background, high contrast disruptive coloration, eliminating shadow, and countershading. In the open ocean, where there is no background, the principal methods of camouflage are transparency, silvering, and countershading, while the ability to produce light is among other things used for counter-illumination on the undersides of cephalopods such as squid. Some animals, such as chameleons and o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lead(II) Azide
Lead(II) azide is an inorganic compound. More so than other azides, is explosive. It is used in detonators to initiate secondary explosives. In a commercially usable form, it is a white to buff powder. Preparation and handling Lead(II) azide is prepared by the reaction of sodium azide and lead(II) nitrate in aqueous solution. Lead(II) acetate can also be used. Thickeners such as dextrin or polyvinyl alcohol are often added to the solution to stabilize the precipitated product. In fact, it is normally shipped in a dextrinated solution that lowers its sensitivity. Production history Lead azide in its pure form was first prepared by Theodor Curtius in 1891. Due to sensitivity and stability concerns, the dextrinated form of lead azide (MIL-L-3055) was developed in the 1920s and 1930s with large scale production by DuPont Co beginning in 1932. Detonator development during World War II resulted in the need for a form of lead azide with a more brisant output. RD-1333 lead azide (MI ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fuse (explosives)
In an explosive, pyrotechnics, pyrotechnic device, or military munition, a fuse (or fuze) is the part of the device that initiates function. In common usage, the word fuse is used indiscriminately. However, when being specific (and in particular in a military context), the term ''fuse'' describes a simple pyrotechnic initiating device, like the cord on a firecracker whereas the term ''fuze'' is used when referring to a more sophisticated ignition device incorporating mechanical and/or electronics, electronic components, such as a proximity fuze for an M107 projectile, M107 artillery shell, magnetometer, magnetic or acoustic signature, acoustic fuze on a sea mine, spring-loaded grenade fuze, pencil detonator, or anti-handling device. History Documented evidence suggests that the earliest fuses were first used by the Song Chinese between the 10th and 12th centuries. After the Chinese invented gunpowder, they began adapting its explosive properties for use in military technology ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasticizers
A plasticizer ( UK: plasticiser) is a substance that is added to a material to make it softer and more flexible, to increase its plasticity, to decrease its viscosity, and/or to decrease friction during its handling in manufacture. Plasticizers are commonly added to polymers such as plastics and rubber, either to facilitate the handling of the raw material during fabrication, or to meet the demands of the end product's application. For example, plasticizers are commonly added to polyvinyl chloride (PVC), which otherwise is hard and brittle, to make it soft and pliable; which makes it suitable for products such as shower curtains, vinyl flooring, clothing, bags, flexible plastic tubing, and electric wire insulation/coating. Plasticizers are also often added to concrete formulations to make them more workable and fluid for pouring, thus allowing the water contents to be reduced. Similarly, they are often added to clays, stucco, solid rocket fuel, and other pastes prior to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phlegmatized
A phlegmatized explosive is an explosive that has had an agent (a phlegmatizer) added to stabilize or desensitize it. Phlegmatizing usually improves the handling properties of an explosive (e.g. when munitions are filled in factories. Alfred Nobel's breakthrough was the use of cellulose nitrate to phlegmatize nitroglycerine. The phlegmatized product is dynamite. TNT explosive can itself be used to phlegmatize more sensitive explosives such as RDX (to form Cyclotol), HMX (to form Octol) or PETN (to form Pentolite). Other typical phlegmatizing agents include paraffin wax (5% used in OKFOL and Composition H6), paper or even water (used in water gel explosives). Such agents are nearly always flammable themselves (therefore adding fuel to the blast) or will at least boil off easily. Typically, a small amount of phlegmatizing agent is used e.g. Composition B, which has 1% paraffin wax added, or the Russian RGO hand grenade which contains 90 grams of "A-IX-1" explosive, comprising 96 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Freon 113
1,1,2-Trichloro-1,2,2-trifluoroethane, also called trichlorotrifluoroethane or CFC-113, is a chlorofluorocarbon. It has the formula . This colorless, volatile liquid is a versatile solvent. Atmospheric reactions CFC-113 is a very unreactive chlorofluorocarbon. It remains in the atmosphere about 90 years, sufficiently long that it will cycle out of the troposphere and into the stratosphere. In the stratosphere, CFC-113 can be broken up by ultraviolet radiation (where sunlight in the 190-225 nm (UV) range), generating chlorine radicals (Cl•), which initiate degradation of ozone requiring only a few minutes: : : This reaction is followed by: : The process regenerates Cl• to destroy more . The Cl• will destroy an average of 100,000 molecules during its atmospheric lifetime of 1–2 years. In some parts of the world, these reactions have significantly thinned the Earth's natural stratospheric ozone layer that shields the biosphere against solar UV radiation; increased UV l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Battle Of Khe Sanh
The Battle of Khe Sanh (21 January – 9 July 1968) was conducted in the Khe Sanh area of northwestern Quảng Trị Province, Republic of Vietnam (South Vietnam), during the Vietnam War. The main US forces defending Khe Sanh Combat Base (KSCB) were two regiments of the United States Marine Corps supported by elements from the United States Army and the United States Air Force (USAF), as well as a small number of Army of the Republic of Vietnam (ARVN) troops. These were pitted against two to three divisional-size elements of the North Vietnamese People's Army of Vietnam (PAVN). The US command in Saigon initially believed that combat operations around KSCB during 1967 were part of a series of minor PAVN offensives in the border regions. That appraisal was later altered when the PAVN was found to be moving major forces into the area. In response, US forces were built up before the PAVN isolated the Marine base. Once the base came under siege, a series of actions were fought over ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viet Cong
, , war = the Vietnam War , image = FNL Flag.svg , caption = The flag of the Viet Cong, adopted in 1960, is a variation on the flag of North Vietnam. Sometimes the lower stripe was green. , active = 1954–1959 ''(as southern Viet Minh cadres)'' , ideology = , position = Far-left , leaders = Liberation Army: Central Office: Liberation Front:Burchett, Wilfred (1963):Liberation Front: Formation of the NLF, ''The Furtive War'', International Publishers, New York. Governance: , merged_into = Vietnamese Fatherland Front , clans = , headquarters = , area = Indochina, with a focus on South Vietnam , predecessor = Viet Minh , successor = Vietnam Fatherland Front , allies = , opponents = , battles = See full list The Viet Cong, ; contraction of (Vietnamese communist) was an armed communist organization in South Vietnam, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
