1.
Shell (projectile)
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A shell is a payload-carrying projectile that, as opposed to shot, contains an explosive or other filling, though modern usage sometimes includes large solid projectiles properly termed shot. Solid shot may contain a pyrotechnic compound if a tracer or spotting charge is used, originally, it was called a bombshell, but shell has come to be unambiguous in a military context. Words cognate with grenade are still used for an artillery or mortar projectile in some European languages, shells are usually large-calibre projectiles fired by artillery, combat vehicles, and warships. Shells usually have the shape of a cylinder topped by a nose for good aerodynamic performance, possibly with a tapering base. Solid cannonballs did not need a fuse, but hollow munitions filled with something such as gunpowder to fragment the ball, needed a fuse, percussion fuses with a spherical projectile presented a challenge because there was no way of ensuring that the impact mechanism hit the target. Therefore, shells needed a fuse that was ignited before or during firing. The earliest record of shells being used in combat was by the Republic of Venice at Jadra in 1376, shells with fuses were used at the 1421 siege of St Boniface in Corsica. These were two hollowed hemispheres of stone or bronze held together by an iron hoop, as described in their book, these hollow, gunpowder-packed shells were made of cast iron. At least since the 16th Century grenades made of ceramics or glass were in use in Central Europe, a hoard of several hundred ceramic greandes were discovered during building works in front of a bastion of the Bavarian City of Ingolstadt, Germany dated to the 17th Century. Lots of the grenades obtained their orignal blackpowder loads and igniters, most probably the grenades were intentionally dumped the moat of the bastion before the year 1723. Early powder burning fuses had to be loaded fuse down to be ignited by firing or a portfire put down the barrel to light the fuse, other shells were wrapped in bitumen cloth, which would ignite during the firing and in turn ignite a powder fuse. Nevertheless, shells came into use in the 16th Century. By the 18th Century, it was known that the fuse towards the muzzle could be lit by the flash through the windage between the shell and the barrel, the use of exploding shells from field artillery became relatively commonplace from early in the 19th century. Until the mid 19th century, shells remained as simple exploding spheres that used gunpowder and they were usually made of cast iron, but bronze, lead, brass and even glass shell casings were experimented with. The word bomb encompassed them at the time, as heard in the lyrics of The Star-Spangled Banner, typically, the thickness of the metal body was about a sixth of their diameter and they were about two thirds the weight of solid shot of the same calibre. To ensure that shells were loaded with their fuses towards the muzzle, in 1819, a committee of British artillery officers recognised that they were essential stores and in 1830 Britain standardised sabot thickness as a half inch. The sabot was also intended to reduce jamming during loading, despite the use of exploding shell, the use of smoothbore cannons, firing spherical projectiles of shot, remained the dominant artillery method until the 1850s. By the late 18th century, artillery could use canister shot to defend itself from infantry or cavalry attack and this involved loading a tin or canvas container filled with small iron or lead balls instead of the usual cannonball
2.
Explosive booster
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An explosive booster is a sensitive explosive charge that acts as a bridge between a conventional detonator and a low-sensitivity explosive such as TNT. By itself, the initiating detonator would not deliver sufficient energy to set off the low-sensitivity charge, however, it detonates the primary charge, which then delivers an explosive shockwave that is sufficient to detonate the secondary, main, high-energy charge. Unlike C4 plastic explosive, not all explosives can be detonated simply by inserting a detonator, therefore, some form of booster is required to amplify the energy released by the detonator so that the main charge will detonate. At first, picric acid was used as a booster to detonate TNT, Tetryl replaced picric acid because it is more stable, and was once a very popular chemical for booster charges, particularly during World War II. However, since then Tetryl has largely replaced by other compositions. Note, booby traps and improvised devices frequently use plastic explosive as the booster charge, for example. This is because any standard detonator will initiate plastic explosive as is, when encountered in connection with artillery shells or air dropped bombs, a booster charge is sometimes referred to as the gaine. At a purely technical level, a sufficiently large detonator would initiate high explosives without the need for a booster charge, however, there are very good reasons why this method is never used. Firstly, there is a safety issue, i. e. detonators are much more sensitive to shock, heat. Therefore, minimising the amount of explosive that users must store or carry greatly reduces the likelihood of serious accidents. A common form for boosters is to cast the material into a cylindrical shell made of cardboard or plastic
3.
Chemistry
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Chemistry is a branch of physical science that studies the composition, structure, properties and change of matter. Chemistry is sometimes called the science because it bridges other natural sciences, including physics. For the differences between chemistry and physics see comparison of chemistry and physics, the history of chemistry can be traced to alchemy, which had been practiced for several millennia in various parts of the world. The word chemistry comes from alchemy, which referred to a set of practices that encompassed elements of chemistry, metallurgy, philosophy, astrology, astronomy, mysticism. An alchemist was called a chemist in popular speech, and later the suffix -ry was added to this to describe the art of the chemist as chemistry, the modern word alchemy in turn is derived from the Arabic word al-kīmīā. In origin, the term is borrowed from the Greek χημία or χημεία and this may have Egyptian origins since al-kīmīā is derived from the Greek χημία, which is in turn derived from the word Chemi or Kimi, which is the ancient name of Egypt in Egyptian. Alternately, al-kīmīā may derive from χημεία, meaning cast together, in retrospect, the definition of chemistry has changed over time, as new discoveries and theories add to the functionality of the science. The term chymistry, in the view of noted scientist Robert Boyle in 1661, in 1837, Jean-Baptiste Dumas considered the word chemistry to refer to the science concerned with the laws and effects of molecular forces. More recently, in 1998, Professor Raymond Chang broadened the definition of chemistry to mean the study of matter, early civilizations, such as the Egyptians Babylonians, Indians amassed practical knowledge concerning the arts of metallurgy, pottery and dyes, but didnt develop a systematic theory. Greek atomism dates back to 440 BC, arising in works by such as Democritus and Epicurus. In 50 BC, the Roman philosopher Lucretius expanded upon the theory in his book De rerum natura, unlike modern concepts of science, Greek atomism was purely philosophical in nature, with little concern for empirical observations and no concern for chemical experiments. Work, particularly the development of distillation, continued in the early Byzantine period with the most famous practitioner being the 4th century Greek-Egyptian Zosimos of Panopolis. He formulated Boyles law, rejected the four elements and proposed a mechanistic alternative of atoms. Before his work, though, many important discoveries had been made, the Scottish chemist Joseph Black and the Dutchman J. B. English scientist John Dalton proposed the theory of atoms, that all substances are composed of indivisible atoms of matter. Davy discovered nine new elements including the alkali metals by extracting them from their oxides with electric current, british William Prout first proposed ordering all the elements by their atomic weight as all atoms had a weight that was an exact multiple of the atomic weight of hydrogen. The inert gases, later called the noble gases were discovered by William Ramsay in collaboration with Lord Rayleigh at the end of the century, thereby filling in the basic structure of the table. Organic chemistry was developed by Justus von Liebig and others, following Friedrich Wöhlers synthesis of urea which proved that organisms were, in theory
4.
Dynamite
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Dynamite is an explosive made of nitroglycerin, sorbents and stabilizers. It was invented by the Swedish chemist and engineer Alfred Nobel in Geesthacht and it rapidly gained wide-scale use as a safer alternative to gun powder and nitroglycerin. Dynamite was invented by Alfred Nobel and was the first safely manageable explosive stronger than black powder, Nobel obtained patents for his invention in England on 7 May 1867, in Sweden on 19 October 1867. After its introduction, dynamite rapidly gained wide-scale use as an alternative to black powder. Nobel tightly controlled the patents, and unlicensed duplicating companies were shut down. However, a few American businessmen got around the patent by using a different formula. Nobel originally sold dynamite as Nobels Blasting Powder but decided to change the name to dynamite, from the Ancient Greek word δύναμις dýnamis, an industrialist, engineer, and inventor, Alfred Nobels father, Immanuel Nobel, built bridges and buildings in Stockholm. His construction work inspired him to new methods of blasting rock. Immanuels work with later on inspired Alfred to make explosives safer. Today dynamite is used in the mining, quarrying, construction. Dynamite is still the product of choice for trenching applications, Dynamite is occasionally used as an initiator or booster for AN and ANFO explosive charges. Nitroglycerin by itself is a strong explosive, but is extremely shock-sensitive, and degrades over time to even more unstable forms. Dynamite combines nitroglycerin with absorbents and stabilizers, rendering it safe to use, the original composition of dynamite consisted of three parts Explosive Oil, one part diatomaceous earth as the absorbent, and a small admixture of sodium carbonate antacid as the stabilizer. Diatomaceous earth is not usually used today as an absorbent medium and it has replaced by cheaper media like sawdust, wood pulp, flour. Other stabilizers like calcium carbonate or zinc oxide can be used in the place of sodium carbonate, sodium nitrate is added to the medium as an oxidizer that improves the dynamites brisance. Dynamite is usually sold in the form of cardboard cylinders about 20 cm long and about 3.2 cm in diameter, a stick of dynamite thus produced contains roughly 1 MJ of energy. Other sizes also exist, rated by either portion or by weight, Dynamite is usually rated by weight strength, usually from 20% to 60%. For example, 40% dynamite is composed of 40% nitroglycerin and 60% dope, the maximum shelf life of nitroglycerin-based dynamite is recommended as one year from the date of manufacture under good storage conditions
5.
ANFO
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ANFO is a widely used bulk industrial explosive. It consists of 94% porous prilled ammonium nitrate, which acts as the agent and absorbent for the fuel. ANFO is also used in avalanche hazard mitigation. It accounts for an estimated 80% of the 2. 7×109 kg of explosives used annually in North America, the press and other media have used the term ANFO loosely and imprecisely in describing IEDs, in cases of fertilizer bombs. The use of ANFO originated in the 1950s, the chemistry of ANFO detonation is the reaction of ammonium nitrate with a long-chain alkane to form nitrogen, carbon dioxide, and water. In an ideal stoichiometrically balanced reaction, ANFO is composed of about 94. 3% AN and 5. 7% FO by weight, in practice, a slight excess of fuel oil is added, as underdosing results in reduced performance while overdosing merely results in more post-blast fumes. When detonation conditions are optimal, the gases are the only products. In practical use, such conditions are impossible to attain, and blasts produce moderate amounts of gases such as carbon monoxide. The fuel component of ANFO is typically diesel, but kerosene, coal dust, racing fuel, finely powdered aluminium in the mixture will sensitise it to detonate more readily. ANFO is classified as an explosive, meaning that it decomposes through detonation rather than deflagration at a velocity higher than the speed of sound in the material. ANFO has a moderate velocity compared to other explosives, measuring 3,200 m/s in 130 mm diameter, unconfined. ANFO is an explosive, meaning that it cannot be set off by the small quantity of primary explosive in a typical blasting cap. A larger quantity of explosive, known as a primer or a booster. One or two sticks of dynamite were used, current practice is to use Tovex or cast boosters of pentolite. In the mining industry, the term ANFO specifically describes a mixture of ammonium nitrate prills. Other explosives based on the ANFO chemistry exist, the most commonly used are emulsions and they differ from ANFO in the physical form the reactants take. The most notable properties of emulsions are water resistance and higher bulk density, while the density of pure crystalline ammonium nitrate is 1700 kg/m3, individual prills of explosive-grade AN measure approximately 1300 kg/m3. Their lower density is due to the presence of a spherical air pocket within each prill
6.
Acetone peroxide
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Acetone peroxide is an organic peroxide and a primary high explosive. It is produced by the oxidation of acetone to yield a mixture of linear monomer and cyclic dimer, trimer, the trimer is known as triacetone triperoxide or tri-cyclic acetone peroxide. Acetone peroxide takes the form of a crystalline powder with a distinctive bleach-like odor and can explode if subjected to heat, friction. As a non-nitrogenous explosive, TATP has historically been difficult to detect. Acetone peroxide was discovered in 1895 by Richard Wolffenstein and he was the first researcher to receive a patent for using the peroxide as an explosive compound. In 1899 Adolf von Baeyer and Victor Villiger described the first synthesis of the dimer, Baeyer and Villiger prepared the dimer by combining potassium persulfate in diethyl ether with acetone, under cooling. After separating the ether layer, the product was purified and found to melt at 132–133°C and they found that the trimer could be prepared by adding hydrochloric acid to a chilled mixture of acetone and hydrogen peroxide. Work on this methodology and on the products obtained, was further investigated in the mid-20th century by Milas. A tetrameric form has also described, under different catalytic conditions. Under neutral conditions, the reaction is reported to produce the organic peroxide. Organic peroxides in general are sensitive, dangerous explosives, and all forms of acetone peroxide are sensitive to initiation, very little heat is created by the explosive decomposition of TATP, the foregoing computational analysis suggests that TATP decomposition as an entropic explosion. However, this hypothesis has been challenged as not conforming to actual measurements, some forms of acetone peroxide are prone to loss by sublimation and evaporation. For these uses, the peroxides are typically in the form of a solution in an organic solvent, methyl ethyl ketone is more common for this purpose. Acetone peroxides are common and unwanted by-products of oxidation reactions, such as used in phenol syntheses. Acetone peroxide is used as a bleaching agent to bleach. Due to their nature, their presence in chemical processes creates potential hazardous situations. Numerous methods are used to reduce their appearance as byproducts—for instance, shifting pH to more alkaline, adjusting reaction temperature, because of its high susceptibility to accidental detonation, TATP has been referred to as the Mother of Satan. It is used by terrorists for its ability to evade detection aimed at nitrogenous explosives, and due to its low cost and it has been described in popular media as easily prepared from readily available retail ingredients, such as hair bleach and nail polish remover
7.
Detonator
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A detonator, frequently a blasting cap, is a device used to trigger an explosive device. Detonators can be chemically, mechanically, or electrically initiated, the two being the most common. The commercial use of explosives uses electrical detonators or the capped fuse which is a length of safety fuse to which an ordinary detonator has been crimped, many detonators primary explosive is a material called ASA compound. This compound is formed from lead azide, lead styphnate and aluminium and is pressed into place above the charge, usually TNT or tetryl in military detonators. Other materials such as DDNP are also used as the charge to reduce the amount of lead emitted into the atmosphere by mining and quarrying operations. Old detonators used mercury fulminate as the primary, often mixed with potassium chlorate to yield better performance. A blasting cap is a small sensitive primary explosive device used to detonate a larger, more powerful and less sensitive secondary explosive such as TNT, dynamite. Blasting caps come in a variety of types, including caps, electric caps. They are used in mining, excavation, and demolition. Electric types are set off by a short burst of current conducted from a machine by a long wire to the cap to ensure safety. Traditional fuse caps have a fuse which is ignited by a flame source, the need for detonators such as blasting caps came from the development of safer explosives. Different explosives require different amounts of energy to detonate, most commercial explosives are formulated with a high activation energy, to make them stable and safe to handle so they will not explode if accidentally dropped, mishandled, or exposed to fire. However they are difficult to detonate intentionally, and require a small initiating explosion. This is provided by a detonator, a detonator contains an easy-to-ignite primary explosive that provides the initial activation energy to start the detonation in the main charge. Explosives commonly used in detonators include mercury fulminate, lead azide, lead styphnate and tetryl, Blasting caps and some detonators are stored separately and not inserted into the main explosive charge until just before use, keeping the main charge safe. Detonators are hazardous for untrained personnel to handle since they contain primary explosive and they are sometimes not recognized as explosives due to their appearance, leading to injuries. Ordinary detonators usually take the form of ignition-based explosives, whilst they are mainly used in commercial operations, ordinary detonators are still used in military operations. This form of detonator is most commonly initiated using safety fuse, well known detonators are lead azide, Pb2, silver azide and mercury fulminate
8.
Chemical compound
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A chemical compound is an entity consisting of two or more atoms, at least two from different elements, which associate via chemical bonds. Many chemical compounds have a numerical identifier assigned by the Chemical Abstracts Service. For example, water is composed of two atoms bonded to one oxygen atom, the chemical formula is H2O. A compound can be converted to a different chemical composition by interaction with a chemical compound via a chemical reaction. In this process, bonds between atoms are broken in both of the compounds, and then bonds are reformed so that new associations are made between atoms. Schematically, this reaction could be described as AB + CD → AC + BD, where A, B, C, and D are each unique atoms, and AB, CD, AC, and BD are each unique compounds. A chemical element bonded to a chemical element is not a chemical compound since only one element. Examples are the diatomic hydrogen and the polyatomic molecule sulfur. Chemical compounds have a unique and defined chemical structure held together in a spatial arrangement by chemical bonds. Pure chemical elements are not considered chemical compounds, failing the two or more atom requirement, though they often consist of molecules composed of multiple atoms. There is varying and sometimes inconsistent nomenclature differentiating substances, which include truly non-stoichiometric examples, from chemical compounds, other compounds regarded as chemically identical may have varying amounts of heavy or light isotopes of the constituent elements, which changes the ratio of elements by mass slightly. Characteristic properties of compounds include that elements in a compound are present in a definite proportion, for example, the molecule of the compound water is composed of hydrogen and oxygen in a ratio of 2,1. In addition, compounds have a set of properties. The physical and chemical properties of compounds differ from those of their constituent elements, however, mixtures can be created by mechanical means alone, but a compound can be created only by a chemical reaction. Some mixtures are so combined that they have some properties similar to compounds. Other examples of compound-like mixtures include intermetallic compounds and solutions of metals in a liquid form of ammonia. Compounds may be described using formulas in various formats, for compounds that exist as molecules, the formula for the molecular unit is shown. For polymeric materials, such as minerals and many metal oxides, the elements in a chemical formula are normally listed in a specific order, called the Hill system
9.
Composition B
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Composition B, colloquially Comp B, is an explosive consisting of castable mixtures of RDX and TNT. It is used as the explosive filling in artillery projectiles, rockets, land mines, hand grenades. It was also used for the lenses in the first implosion-type nuclear weapons developed by the United States. The standard proportions of ingredients are 59. 5% RDX and 39. 4% TNT, most commonly it is described as 60/40 RDX/TNT with 1% wax added. M65 bombs from this period were responsible for the 1967 USS Forrestal fire, some NATO-approved munitions suppliers such as Mecar have continued to use Composition B in their products. Composition B is related to Cyclotol, which has a proportion of RDX. IMX-101 is slowly replacing Comp B in US military artillery shells, and IMX-104 in mortar rounds
10.
Detonation
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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 occur in both solid and liquid explosives, as well as in reactive gases. The velocity of detonation in solid and liquid explosives is much higher than that in gaseous ones, a very wide variety of fuels may occur as gases, droplet fogs, or dust suspensions. Oxidants include halogens, ozone, hydrogen peroxide and oxides of nitrogen, gaseous detonations are often associated with a mixture of fuel and oxidant in a composition somewhat below conventional flammability ratios. They happen most often in confined systems, but they occur in large vapor clouds. Other materials, such as acetylene, ozone, and hydrogen peroxide are detonable in the absence of oxygen, processes involved in the transition between deflagration and detonation are covered thoroughly for gases by Nettleton. The simplest theory to predict the behaviour of detonations in gases is known as Chapman-Jouguet theory and this theory, described by a relatively simple set of algebraic equations, models the detonation as a propagating shock wave accompanied by exothermic heat release. Such a theory confines the chemistry and diffusive transport processes to a thin zone. A more complex theory was advanced during World War II independently by Zeldovich, von Neumann and this theory, now known as ZND theory, admits finite-rate chemical reactions and thus describes a detonation as an infinitely thin shock wave followed by a zone of exothermic chemical reaction. With a reference frame of a shock, the following flow is subsonic, so that an acoustic reaction zone follows immediately behind the lead front. There is also evidence that the reaction zone is semi-metallic in some explosives. Both theories describe one-dimensional and steady wave fronts, indeed, such waves are quenched as their structure is destroyed. The Wood-Kirkwood detonation theory can correct for some of these limitations, experimental studies have revealed some of the conditions needed for the propagation of such fronts. The influence of increasing the concentration of diluent on expanding individual detonation cells has been elegantly demonstrated, similarly their size grows as the initial pressure falls. Since cell widths must be matched with minimum dimension of containment, mathematical modeling has steadily advanced to predicting the complex flow fields behind shocks inducing reactions. To date, none has adequately described how structure is formed and sustained behind unconfined waves, when used in explosive devices, the main cause of damage from a detonation is the supersonic blast front in the surrounding area. This is a significant distinction from deflagrations where the wave is subsonic. Therefore, detonation is most often used for explosives and the acceleration of projectiles, pulse detonation engines use the detonation wave for aerospace propulsion
11.
Water gel explosive
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A water-gel explosive is a fuel sensitized explosive mixture consisting of an aqueous ammonium nitrate solution that acts as the oxidizer. Water gels that are cap-insensitive are referred to under United States safety regulations as blasting agents, water gel explosives have a jelly-like consistency and come in sausage-like packing stapled shut on both sides. Water-gel explosives have almost completely displaced dynamite, becoming the most-used civil blasting agents, water gels usually have many different ingredients. They contain a gelatinizing agent, also known as a thickener, polyvinyl alcohol, guar gum, dextran gums, and urea-formaldehyde resins are the typical gelling agents. Guar, specifically, is an agent used for the aqueous portion of the water gel explosives. The primary component of water gels is monomethylamine nitrate, monomethylamine nitrate is made from monomethyl amine and nitric acid. Water gel explosives are made of ammonium nitrate, calcium nitrate, aluminum, ethylene glycol. The proportions of these components vary depending on the desired explosiveness of the water gel, water gel explosives are produced by combining nitroparaffins, usually nitromethane, with an aqueous salt solution and a gelling agent. These nitroparaffins typically make up most of the water gel explosive, different types of gelling agents are used to create the water gel explosive. One agent is insoluble in water, but able to gel with nitromethane, the gel used for nitromethane is cyanoethylether, a derivative of galactomannan gum. Other agents are water-soluble and are used for the salt solution. As referenced in the first paragraph, water-soluble gums and gel modifiers like guar can be used for the gelling of aqueous solutions, when the salt solution and nitroparaffin are gelled, the entire mixture is combined and mixed together until the desired consistency is achieved. One characteristic that allows the explosive to work so well is the nature of the nitroparaffin. The effectiveness of the water gels is dependent on the dissemination of salts in the salt solution, the particles need to be very small and fine so that they can be dispersed well throughout the solution. Some salts that are used include, ammonium nitrate, sodium nitrate, sodium perchlorate. The sensitivity of the explosive must be increased in order to improve the initiation of the detonation of the explosive, there are different techniques for increasing the sensitivity. Aluminum or other powdered metals can help increase the sensitivity of the water gel, powdered metals have not proven to be completely effective in increasing the sensitivity of the explosive because they do not uniformly mix through the solution. They also lose sensitivity as storage time increases, liquid non-self-explosive sensitizers like nitrobenzene and liquid nitrotoluene have not worked well either because they are difficult to hold in suspension
12.
Nitrogen triiodide
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Nitrogen triiodide is the inorganic compound with the formula NI3. NI3 has a complex structural chemistry that is difficult to study because of the instability of the derivatives, Nitrogen triiodide was first characterized by Raman spectroscopy in 1990 when it was prepared by an ammonia-free route. The material that is called nitrogen triiodide is prepared by the reaction of iodine with ammonia. When this reaction is conducted at low temperatures in anhydrous ammonia, the product is NI3 ·5. This adduct was first reported by Bernard Courtois in 1812, and its solid state structure consists of chains of -NI2-I-NI2-I-NI2-I-. Ammonia molecules are situated between the chains, when kept cold in the dark and damp with ammonia, NI3 · NH3 is stable. This results in a low activation energy for its decomposition. Nitrogen triiodide has no commercial value due to its extreme shock sensitivity, making it impossible to store, transport. An alternate method of removal is to simply allow the iodine time to sublime. Small amounts of nitrogen triiodide are sometimes synthesized as a demonstration to high school students or as an act of chemical magic. To highlight the sensitivity of the compound, it is detonated by touching it with a feather but even the slightest air current, laser light. Nitrogen triiodide is also notable for being the known chemical explosive that detonates when exposed to alpha particles. See the explosion Nitrogen Tri-Iodide – explains why the compound is explosive Nitrogen Tri-Iodide Detonation on Youtube
