|
Mine Shell
A mine shell (from the German term ''Minengeschoß'', "mine shot"), also known as High-Explosive, High-Capacity (HEHC) in British military nomenclature, is a military explosive shell type characterized by thin (usually steel) shell walls and a correspondingly high quantity of explosives, much higher than the traditional high explosive shell type per caliber, meaning that mine shells trade fragmentation effect (due to the thinner shell walls) for a higher pressure wave effect when comparing to traditional high explosive shells. Mine shells were originally developed during the mid to late 1800s against fortresses prior to rebar but got a new role during World War II against air targets as reinforced fortresses had made the original use of the type obsolete around World War I. Effect, construction and use The mine shell is a more explosive version of the common high-explosive and high-explosive fragmentation shells, relying on inflicting damage primarily through the blast (press ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Explosion
An explosion is a rapid expansion in volume associated with an extreme outward release of energy, usually with the generation of high temperatures and release of high-pressure gases. Supersonic explosions created by high explosives are known as detonations and travel through shock waves. Subsonic explosions are created by low explosives through a slower combustion process known as deflagration. Causes Explosions can occur in nature due to a large influx of energy. Most natural explosions arise from volcanic or stellar processes of various sorts. Explosive volcanic eruptions occur when magma rises from below, it has very dissolved gas in it. The reduction of pressure as the magma rises and causes the gas to bubble out of solution, resulting in a rapid increase in volume. Explosions also occur as a result of impact events and in phenomena such as hydrothermal explosions (also due to volcanic processes). Explosions can also occur outside of Earth in the universe in events su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Naval Mine
A naval mine is a self-contained explosive device placed in water to damage or destroy surface ships or submarines. Unlike depth charges, mines are deposited and left to wait until they are triggered by the approach of, or contact with, any vessel or a particular vessel type, akin to anti-infantry vs. anti-vehicle mines. Naval mines can be used offensively, to hamper enemy shipping movements or lock vessels into a harbour; or defensively, to protect friendly vessels and create "safe" zones. Mines allow the minelaying force commander to concentrate warships or defensive assets in mine-free areas giving the adversary three choices: undertake an expensive and time-consuming minesweeping effort, accept the casualties of challenging the minefield, or use the unmined waters where the greatest concentration of enemy firepower will be encountered. Although international law requires signatory nations to declare mined areas, precise locations remain secret; and non-complying individ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 automatically by way of pressure when a target steps on it or drives over it, although other detonation mechanisms are also sometimes used. A land mine may cause damage by direct blast effect, by fragments that are thrown by the blast, or by both. Landmines are typically laid throughout an area, creating a ''minefield'' which is dangerous to cross. The use of land mines is controversial because of their potential as indiscriminate weapons. They can remain dangerous many years after a conflict has ended, harming civilians and the economy. Seventy-eight countries are contaminated with land mines and 15,000–20,000 people are killed every year while many more are injured. Approximately 80% of land mine casualties are civilians, with children as the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fougasse (weapon)
A fougasse is an improvised mortar constructed by making a hollow in the ground or rock and filling it with explosives (originally, black powder) and projectiles. The fougasse was used by Samuel Zimmermann at AugsburgThe Origins of Military Mines', Major William C. Schneck, Engineer Bulletin July 1998 in the sixteenth century, referred to by Vauban in the seventeenth century, and well known to military engineers by the mid-eighteenth century. This technique was used in several European wars, the American Revolution, and the American Civil War. The term is still used to describe such devices. Firing The normal method of firing was to use a burning torch or slow match to ignite a '' saucisson'' (French for "sausage", a cloth or leather tube waterproofed with pitch and filled with black powder) leading to the main charge. This had numerous disadvantages; the firer was obvious to the attacking enemy, and had to run to get clear after lighting the fuse. The black powder was also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Battle Of The Crater
The Battle of the Crater was a battle of the American Civil War, part of the siege of Petersburg. It took place on Saturday, July 30, 1864, between the Confederate Army of Northern Virginia, commanded by General Robert E. Lee, and the Union Army of the Potomac, commanded by Major General George G. Meade (under the direct supervision of the general-in-chief, Lieutenant General Ulysses S. Grant). After weeks of preparation, on July 30 Union forces exploded a mine in Major General Ambrose E. Burnside's IX Corps sector, blowing a gap in the Confederate defenses of Petersburg, Virginia. At that point, everything deteriorated rapidly for the Union attackers. Unit after unit charged into and around the crater, where most of them milled in confusion in the bottom of the crater. Grant considered this failed assault as "the saddest affair I have witnessed in this war." The Confederates quickly recovered, and launched several counterattacks led by Brigadier General William Mahone. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tunnel Warfare
Tunnel warfare involves war being conducted in tunnel and other underground cavities. It often includes the construction of underground facilities (mining or undermining) in order to attack or defend, and the use of existing natural caves and artificial underground facilities for military purposes. Tunnels can be used to undermine fortifications and slip into enemy territory for a surprise attack, while it can strengthen a defense by creating the possibility of ambush, counterattack and the ability to transfer troops from one portion of the battleground to another unseen and protected. Also, tunnels can serve as shelter from enemy attack. Since antiquity, sappers have used mining against walled cites, fortresses, castles or other strongly held and fortified military positions. Defenders have dug counter-mines to attack miners or destroy a mine threatening their fortifications. Since tunnels are commonplace in urban areas, tunnel warfare is often a feature, though usually a min ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Civil War
The American Civil War (April 12, 1861 – May 26, 1865; also known by other names) was a civil war in the United States. It was fought between the Union ("the North") and the Confederacy ("the South"), the latter formed by states that had seceded. The central cause of the war was the dispute over whether slavery would be permitted to expand into the western territories, leading to more slave states, or be prevented from doing so, which was widely believed would place slavery on a course of ultimate extinction. Decades of political controversy over slavery were brought to a head by the victory in the 1860 U.S. presidential election of Abraham Lincoln, who opposed slavery's expansion into the west. An initial seven southern slave states responded to Lincoln's victory by seceding from the United States and, in 1861, forming the Confederacy. The Confederacy seized U.S. forts and other federal assets within their borders. Led by Confederate President Jefferson Da ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blowback (firearms)
Blowback is a system of operation for self-loading firearms that obtains energy from the motion of the cartridge case as it is pushed to the rear by expanding gas created by the ignition of the propellant charge. Several blowback systems exist within this broad principle of operation, each distinguished by the methods used to control bolt movement. In most actions that use blowback operation, the breech is not locked mechanically at the time of firing: the inertia of the bolt and recoil , relative to the weight of the bullet, delay opening of the breech until the bullet has left the barrel. A few locked breech designs use a form of blowback (example: primer actuation) to perform the unlocking function. The blowback principle may be considered a simplified form of gas operation, since the cartridge case behaves like a piston driven by the powder gases. Other operating principles for self-loading firearms include delayed blowback, blow forward, gas operation, and recoil operat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Recoil Operated
Recoil operation is an operating mechanism used to implement locked breech, autoloading firearms. Recoil operated firearms use the energy of recoil to cycle the action, as opposed to gas operation or blowback operation using the pressure of the propellant gas. The earliest mention of recoil used to assist the loading of firearms is sometimes claimed to be in 1663 when an Englishman called Palmer proposed to employ either it or gases tapped along a barrel to do so. However no one has been able to verify this claim in recent times, although there is another automatic gun that dates from the same year, but its type and method of operation are unknown. Recoil-operation, if it was invented in 1663, would then lay dormant until the 19th century, when a number of inventors started to patent designs featuring recoil operation; this was due to the fact that the integrated disposable cartridge (both bullet and propellant in one easily interchangeable unit) made these designs viable. The e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brittle
A material is brittle if, when subjected to stress, it fractures with little elastic deformation and without significant plastic deformation. Brittle materials absorb relatively little energy prior to fracture, even those of high strength. Breaking is often accompanied by a sharp snapping sound. When used in materials science, it is generally applied to materials that fail when there is little or no plastic deformation before failure. One proof is to match the broken halves, which should fit exactly since no plastic deformation has occurred. Brittleness in different materials Polymers Mechanical characteristics of polymers can be sensitive to temperature changes near room temperatures. For example, poly(methyl methacrylate) is extremely brittle at temperature 4˚C, but experiences increased ductility with increased temperature. Amorphous polymers are polymers that can behave differently at different temperatures. They may behave like a glass at low temperatures (the glassy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aircraft Skin
The skin of an aircraft is the outer surface which covers much of its wings and fuselage. The most commonly used materials are aluminum and aluminium alloys with other metals, including zinc, magnesium and copper Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkis .... History As the twentieth century progressed, aluminum became an essential metal in aircraft. The cylinder block of the engine that powered the Wright brothers’ plane at Kitty Hawk in 1903 was a one-piece casting in an aluminum alloy containing 8% copper; aluminum propeller blades appeared as early as 1907; and aluminum covers, seats, cowlings, cast brackets, and similar parts were common by the beginning of the First World War. In 1916, L. Brequet designed a reconnaissance bomber that marked the initial use of aluminum i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Tunnel Warfare")
