82-607: Dynamite is an explosive made of nitroglycerin , sorbents (such as powdered shells or clay), and stabilizers . It was invented by the Swedish chemist and engineer Alfred Nobel in Geesthacht , Northern Germany, and was patented in 1867. It rapidly gained wide-scale use as a more robust alternative to the traditional black powder explosives. It allows the use of nitroglycerine's favorable explosive properties while greatly reducing its risk of accidental detonation. Dynamite
164-431: A 20% cartridge strength would mean the stick was equal to an equivalent weight strength of 20% ANFO. "Military dynamite" (or M1 dynamite) is a dynamite substitute made with more stable ingredients than nitroglycerin. It contains 75% RDX , 15% TNT and 10 percent desensitizers and plasticizers. It has only 60 percent equivalent strength as commercial dynamite, but is much safer to store and handle. Various countries around
246-420: A chemically pure compound, such as nitroglycerin , or a mixture of a fuel and an oxidizer , such as black powder or grain dust and air. Some chemical compounds are unstable in that, when shocked, they react, possibly to the point of detonation. Each molecule of the compound dissociates into two or more new molecules (generally gases) with the release of energy. The above compositions may describe most of
328-494: A controlled explosion set off from a distance using a fuse . In 1863 Nobel performed his first successful detonation of pure nitroglycerin, using a blasting cap made of a copper percussion cap and mercury fulminate . In 1864, Alfred Nobel filed patents for both the blasting cap and his method of synthesizing nitroglycerin, using sulfuric acid , nitric acid and glycerin. On 3 September 1864, while experimenting with nitroglycerin, Emil and several others were killed in an explosion at
410-634: A degree of water resistance. Explosives based on ammonium nitrate have little or no water resistance as ammonium nitrate is highly soluble in water and is hygroscopic. Many explosives are toxic to some extent. Manufacturing inputs can also be organic compounds or hazardous materials that require special handling due to risks (such as carcinogens ). The decomposition products, residual solids, or gases of some explosives can be toxic, whereas others are harmless, such as carbon dioxide and water. Examples of harmful by-products are: "Green explosives" seek to reduce environment and health impacts. An example of such
492-450: A drop-hammer: about 100 mg of explosive is placed on an anvil, upon which a weight of between 0.5 and 10 kg (1 and 22 lb) is dropped from different heights until detonation is achieved. With a hammer of 2 kg, mercury fulminate detonates with a drop distance of 1 to 2 cm, nitroglycerin with 4 to 5 cm, dynamite with 15 to 30 cm, and ammoniacal explosives with 40 to 50 cm. For several decades beginning in
574-485: A force vector and a displacement vector. By contrast, torque is a vector – the cross product of a force vector and a distance vector. Torque and energy are related to one another by the equation E = τ θ , {\displaystyle E=\tau \theta \,,} where E is energy, τ is (the vector magnitude of) torque, and θ is the angle swept (in radians ). Since plane angles are dimensionless, it follows that torque and energy have
656-415: A form of explosive that used ammonium nitrate as a substitute for the more costly nitroglycerin. Ammonium nitrate has only 85% of the chemical energy of nitroglycerin. It is rated by either "weight strength" (the amount of ammonium nitrate in the medium) or "cartridge strength" (the potential explosive strength generated by an amount of explosive of a certain density and grain size used in comparison to
738-469: A mass of about 190 grams ( 1 ⁄ 2 troy pound). A stick of dynamite thus produced contains roughly 1 MJ ( megajoule ) of energy. Other sizes also exist, rated by either portion (Quarter-Stick or Half-Stick) or by weight. Dynamite is usually rated by "weight strength" (the amount of nitroglycerin it contains), usually from 20% to 60%. For example, 40% dynamite is composed of 40% nitroglycerin and 60% "dope" (the absorbent storage medium mixed with
820-433: A number of more exotic explosive materials, and exotic methods of causing explosions. Examples include nuclear explosives , and abruptly heating a substance to a plasma state with a high-intensity laser or electric arc . Laser- and arc-heating are used in laser detonators, exploding-bridgewire detonators , and exploding foil initiators , where a shock wave and then detonation in conventional chemical explosive material
902-447: A physical shock signal. In other situations, different signals such as electrical or physical shock, or, in the case of laser detonation systems, light, are used to initiate an action, i.e., an explosion. A small quantity, usually milligrams, is sufficient to initiate a larger charge of explosive that is usually safer to handle. Megajoule The joule ( / dʒ uː l / JOOL , or / dʒ aʊ l / JOWL ; symbol: J )
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#1732783844594984-685: A practical measure, primary explosives are sufficiently sensitive that they can be reliably initiated with a blow from a hammer; however, PETN can also usually be initiated in this manner, so this is only a very broad guideline. Additionally, several compounds, such as nitrogen triiodide , are so sensitive that they cannot even be handled without detonating. Nitrogen triiodide is so sensitive that it can be reliably detonated by exposure to alpha radiation . Primary explosives are often used in detonators or to trigger larger charges of less sensitive secondary explosives . Primary explosives are commonly used in blasting caps and percussion caps to translate
1066-399: A reaction to be classified as a detonation as opposed to just a deflagration, the propagation of the reaction shockwave through the material being tested must be faster than the speed of sound through that material. The speed of sound through a liquid or solid material is usually orders of magnitude faster than the speed of sound through air or other gases. Traditional explosives mechanics
1148-735: A smaller number are manufactured specifically for the purpose of being used as explosives. The remainder are too dangerous, sensitive, toxic, expensive, unstable, or prone to decomposition or degradation over short time spans. In contrast, some materials are merely combustible or flammable if they burn without exploding. The distinction, however, is not very clear. Certain materials—dusts, powders, gases, or volatile organic liquids—may be simply combustible or flammable under ordinary conditions, but become explosive in specific situations or forms, such as dispersed airborne clouds , or confinement or sudden release . Early thermal weapons , such as Greek fire , have existed since ancient times. At its roots,
1230-618: A thermodynamically favorable process in addition to one that propagates very rapidly. Thus, explosives are substances that contain a large amount of energy stored in chemical bonds . The energetic stability of the gaseous products and hence their generation comes from the formation of strongly bonded species like carbon monoxide, carbon dioxide, and nitrogen gas, which contain strong double and triple bonds having bond strengths of nearly 1 MJ/mole. Consequently, most commercial explosives are organic compounds containing –NO 2 , –ONO 2 and –NHNO 2 groups that, when detonated, release gases like
1312-709: Is mining . Whether the mine is on the surface or is buried underground, the detonation or deflagration of either a high or low explosive in a confined space can be used to liberate a fairly specific sub-volume of a brittle material (rock) in a much larger volume of the same or similar material. The mining industry tends to use nitrate-based explosives such as emulsions of fuel oil and ammonium nitrate solutions, mixtures of ammonium nitrate prills (fertilizer pellets) and fuel oil ( ANFO ) and gelatinous suspensions or slurries of ammonium nitrate and combustible fuels. In materials science and engineering, explosives are used in cladding ( explosion welding ). A thin plate of some material
1394-405: Is a measured quantity of explosive material, which may either be composed solely of one ingredient or be a mixture containing at least two substances. The potential energy stored in an explosive material may, for example, be: Explosive materials may be categorized by the speed at which they expand. Materials that detonate (the front of the chemical reaction moves faster through the material than
1476-427: Is a pure substance ( molecule ) that in a chemical reaction can contribute some atoms of one or more oxidizing elements, in which the fuel component of the explosive burns. On the simplest level, the oxidizer may itself be an oxidizing element , such as gaseous or liquid oxygen . The availability and cost of explosives are determined by the availability of the raw materials and the cost, complexity, and safety of
1558-539: Is a second generation castable explosive adopted by the military, while dynamite, in contrast, has never been popular in warfare because it degenerates quickly under severe conditions and can be detonated by either fire or a wayward bullet. The German armed forces adopted TNT as a filling for artillery shells in 1902, some 40 years after the invention of dynamite, which is a first generation phlegmatized explosive primarily intended for civilian earthmoving. TNT has never been popular or widespread in civilian earthmoving, as it
1640-446: Is also equivalent to any of the following: The joule is named after James Prescott Joule . As with every SI unit named for a person, its symbol starts with an upper case letter (J), but when written in full, it follows the rules for capitalisation of a common noun ; i.e., joule becomes capitalised at the beginning of a sentence and in titles but is otherwise in lower case. The cgs system had been declared official in 1881, at
1722-402: Is an important consideration in selecting an explosive for a particular purpose. The explosive in an armor-piercing projectile must be relatively insensitive, or the shock of impact would cause it to detonate before it penetrated to the point desired. The explosive lenses around nuclear charges are also designed to be highly insensitive, to minimize the risk of accidental detonation. The index of
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#17327838445941804-440: Is an important element influencing the yield of the energy transmitted for both atmospheric over-pressure and ground acceleration. By definition, a "low explosive", such as black powder, or smokeless gunpowder has a burn rate of 171–631 m/s. In contrast, a "high explosive", whether a primary, such as detonating cord , or a secondary, such as TNT or C-4, has a significantly higher burn rate about 6900–8092 m/s. Stability
1886-520: Is based on the shock-sensitive rapid oxidation of carbon and hydrogen to carbon dioxide, carbon monoxide and water in the form of steam. Nitrates typically provide the required oxygen to burn the carbon and hydrogen fuel. High explosives tend to have the oxygen, carbon and hydrogen contained in one organic molecule, and less sensitive explosives like ANFO are combinations of fuel (carbon and hydrogen fuel oil) and ammonium nitrate . A sensitizer such as powdered aluminum may be added to an explosive to increase
1968-508: Is considerably more expensive and less powerful by weight than dynamite, as well as being slower to mix and pack into boreholes. TNT's primary asset is its remarkable insensitivity and stability: it is waterproof and incapable of detonating without the extreme shock and heat provided by a blasting cap (or a sympathetic detonation ); this stability also allows it to be melted at 81 °C (178 °F), poured into high explosive shells and allowed to re-solidify, with no extra danger or change in
2050-443: Is created by laser- or electric-arc heating. Laser and electric energy are not currently used in practice to generate most of the required energy, but only to initiate reactions. To determine the suitability of an explosive substance for a particular use, its physical properties must first be known. The usefulness of an explosive can only be appreciated when the properties and the factors affecting them are fully understood. Some of
2132-533: Is equal to (approximately unless otherwise stated): Units with exact equivalents in joules include: In mechanics , the concept of force (in some direction) has a close analogue in the concept of torque (about some angle): A result of this similarity is that the SI unit for torque is the newton-metre , which works out algebraically to have the same dimensions as the joule, but they are not interchangeable. The General Conference on Weights and Measures has given
2214-452: Is evaluated by a tailored series of tests to assess the material for its intended use. Of the tests listed below, cylinder expansion and air-blast tests are common to most testing programs, and the others support specific applications. In addition to strength, explosives display a second characteristic, which is their shattering effect or brisance (from the French meaning to "break"). Brisance
2296-472: Is important in determining the effectiveness of an explosion in fragmenting shells, bomb casings, and grenades . The rapidity with which an explosive reaches its peak pressure ( power ) is a measure of its brisance. Brisance values are primarily employed in France and Russia. The sand crush test is commonly employed to determine the relative brisance in comparison to TNT. No test is capable of directly comparing
2378-547: Is often assumed to be the same as (or confused for) dynamite largely because of the ubiquity of both explosives during the 20th century. This incorrect connection between TNT and dynamite was enhanced by cartoons such as Bugs Bunny , where animators labeled any kind of bomb (ranging from sticks of dynamite to kegs of black powder ) as TNT, because the acronym was shorter and more memorable and did not require literacy to recognize that TNT meant "bomb". Aside from both being high explosives, TNT and dynamite have little in common. TNT
2460-400: Is placed atop a thick layer of a different material, both layers typically of metal. Atop the thin layer is placed an explosive. At one end of the layer of explosive, the explosion is initiated. The two metallic layers are forced together at high speed and with great force. The explosion spreads from the initiation site throughout the explosive. Ideally, this produces a metallurgical bond between
2542-473: Is the ability of an explosive to be stored without deterioration . The following factors affect the stability of an explosive: The term power or performance as applied to an explosive refers to its ability to do work. In practice it is defined as the explosive's ability to accomplish what is intended in the way of energy delivery (i.e., fragment projection, air blast, high-velocity jet, underwater shock and bubble energy, etc.). Explosive power or performance
Dynamite - Misplaced Pages Continue
2624-411: Is the lead-free primary explosive copper(I) 5-nitrotetrazolate, an alternative to lead azide . Explosive material may be incorporated in the explosive train of a device or system. An example is a pyrotechnic lead igniting a booster, which causes the main charge to detonate. The most widely used explosives are condensed liquids or solids converted to gaseous products by explosive chemical reactions and
2706-655: Is the unit of energy in the International System of Units (SI). It is equal to the amount of work done when a force of one newton displaces a mass through a distance of one metre in the direction of that force. It is also the energy dissipated as heat when an electric current of one ampere passes through a resistance of one ohm for one second. It is named after the English physicist James Prescott Joule (1818–1889). In terms of SI base units and in terms of SI derived units with special names ,
2788-407: Is used to describe an explosive phenomenon whereby the decomposition is propagated by a shock wave traversing the explosive material at speeds greater than the speed of sound within the substance. The shock front is capable of passing through the high explosive material at supersonic speeds — typically thousands of metres per second. In addition to chemical explosives, there are
2870-614: The Atlas Powder Company , which took up the manufacture of dynamite (in different formulations). Currently, only Dyno Nobel manufactures dynamite in the US. The only facility producing it is located in Carthage, Missouri , but the material is purchased from Dyno Nobel by other manufacturers who put their labels on the dynamite and boxes. Other explosives are often referred to or confused with dynamite: Trinitrotoluene (TNT)
2952-425: The speed of sound ) are said to be "high explosives" and materials that deflagrate are said to be "low explosives". Explosives may also be categorized by their sensitivity . Sensitive materials that can be initiated by a relatively small amount of heat or pressure are primary explosives and materials that are relatively insensitive are secondary or tertiary explosives . A wide variety of chemicals can explode;
3034-571: The 1940s, the largest producer of dynamite in the world was the Union of South Africa . There the De Beers company established a factory in 1902 at Somerset West . The explosives factory was later operated by AECI (African Explosives and Chemical Industries). The demand for the product came mainly from the country's vast gold mines, centered on the Witwatersrand . The factory at Somerset West
3116-583: The TNT's characteristics. Accordingly, more than 90% of the TNT produced in America was always for the military market, with most TNT used for filling shells, hand grenades and aerial bombs , and the remainder being packaged in brown "bricks" (not red cylinders) for use as demolition charges by combat engineers . In the United States, in 1885, the chemist Russell S. Penniman invented "ammonium dynamite",
3198-413: The aforementioned (e.g., nitroglycerin , TNT , HMX , PETN , nitrocellulose ). An explosive is classified as a low or high explosive according to its rate of combustion : low explosives burn rapidly (or deflagrate ), while high explosives detonate . While these definitions are distinct, the problem of precisely measuring rapid decomposition makes practical classification of explosives difficult. For
3280-418: The age of 17, Alfred Nobel was sent abroad for two years ; in the United States he met Swedish engineer John Ericsson and in France studied under famed chemist Théophile-Jules Pelouze and his pupil Ascanio Sobrero , who had first synthesized nitroglycerin in 1847. Pelouze cautioned Nobel against using nitroglycerine as a commercial explosive because of its great sensitivity to shock. In 1857, Nobel filed
3362-564: The blasts upward. There were several other explosions at the Modderfontein factory. After 1985, pressure from trade unions forced AECI to phase out the production of dynamite. The factory then went on to produce ammonium nitrate emulsion-based explosives that are safer to manufacture and handle. Dynamite was first manufactured in the US by the Giant Powder Company of San Francisco , California, whose founder had obtained
Dynamite - Misplaced Pages Continue
3444-479: The capacity of an explosive to be initiated into detonation in a sustained manner. It is defined by the power of the detonator which is certain to prime the explosive to a sustained and continuous detonation. Reference is made to the Sellier-Bellot scale that consists of a series of 10 detonators, from n. 1 to n. 10 , each of which corresponds to an increasing charge weight. In practice, most of
3526-425: The choice being determined by the characteristics of the explosive. Dependent upon the method employed, an average density of the loaded charge can be obtained that is within 80–99% of the theoretical maximum density of the explosive. High load density can reduce sensitivity by making the mass more resistant to internal friction . However, if density is increased to the extent that individual crystals are crushed,
3608-421: The development of pressure within rounds of ammunition and separation of mixtures into their constituents. Volatility affects the chemical composition of the explosive such that a marked reduction in stability may occur, which results in an increase in the danger of handling. The introduction of water into an explosive is highly undesirable since it reduces the sensitivity, strength, and velocity of detonation of
3690-498: The energy of the detonation. Once detonated, the nitrogen portion of the explosive formulation emerges as nitrogen gas and toxic nitric oxides . The chemical decomposition of an explosive may take years, days, hours, or a fraction of a second. The slower processes of decomposition take place in storage and are of interest only from a stability standpoint. Of more interest are the other two rapid forms besides decomposition: deflagration and detonation. In deflagration, decomposition of
3772-604: The energy released by those reactions. The gaseous products of complete reaction are typically carbon dioxide , steam , and nitrogen . Gaseous volumes computed by the ideal gas law tend to be too large at high pressures characteristic of explosions. Ultimate volume expansion may be estimated at three orders of magnitude, or one liter per gram of explosive. Explosives with an oxygen deficit will generate soot or gases like carbon monoxide and hydrogen , which may react with surrounding materials such as atmospheric oxygen . Attempts to obtain more precise volume estimates must consider
3854-544: The exclusive rights from Nobel in 1867. Giant was eventually acquired by DuPont , which produced dynamite under the Giant name until Giant was dissolved by DuPont in 1905. Thereafter, DuPont produced dynamite under its own name until 1911–12, when its explosives monopoly was broken up by the U.S. Circuit Court in the "Powder Case". Two new companies were formed upon the breakup, the Hercules Powder Company and
3936-445: The explosive material is propagated by a flame front which moves relatively slowly through the explosive material, i.e. at speeds less than the speed of sound within the substance (which is usually still higher than 340 m/s or 1,220 km/h in most liquid or solid materials) in contrast to detonation, which occurs at speeds greater than the speed of sound. Deflagration is a characteristic of low explosive material. This term
4018-651: The explosive material, but a practical explosive will often include small percentages of other substances. For example, dynamite is a mixture of highly sensitive nitroglycerin with sawdust , powdered silica , or most commonly diatomaceous earth , which act as stabilizers. Plastics and polymers may be added to bind powders of explosive compounds; waxes may be incorporated to make them safer to handle; aluminium powder may be introduced to increase total energy and blast effects. Explosive compounds are also often "alloyed": HMX or RDX powders may be mixed (typically by melt-casting) with TNT to form Octol or Cyclotol . An oxidizer
4100-442: The explosive may become more sensitive. Increased load density also permits the use of more explosive, thereby increasing the power of the warhead . It is possible to compress an explosive beyond a point of sensitivity, known also as dead-pressing , in which the material is no longer capable of being reliably initiated, if at all. Volatility is the readiness with which a substance vaporizes . Excessive volatility often results in
4182-414: The explosive properties of two or more compounds; it is important to examine the data from several such tests (sand crush, trauzl , and so forth) in order to gauge relative brisance. True values for comparison require field experiments. Density of loading refers to the mass of an explosive per unit volume. Several methods of loading are available, including pellet loading, cast loading, and press loading,
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#17327838445944264-504: The explosive strength generated by an equivalent density and grain size of a standard explosive). For example, high-explosive 65% Extra dynamite has a weight strength of 65% ammonium nitrate and 35% "dope" (the absorbent medium mixed with the stabilizers and additives). Its "cartridge strength" would be its weight in pounds times its strength in relation to an equal amount of ANFO (the civilian baseline standard) or TNT (the military baseline standard). For example, 65% ammonium dynamite with
4346-409: The explosive. Hygroscopicity is a measure of a material's moisture-absorbing tendencies. Moisture affects explosives adversely by acting as an inert material that absorbs heat when vaporized, and by acting as a solvent medium that can cause undesired chemical reactions. Sensitivity, strength, and velocity of detonation are reduced by inert materials that reduce the continuity of the explosive mass. When
4428-429: The explosives on the market today are sensitive to an n. 8 detonator, where the charge corresponds to 2 grams of mercury fulminate . The velocity with which the reaction process propagates in the mass of the explosive. Most commercial mining explosives have detonation velocities ranging from 1,800 m/s to 8,000 m/s. Today, velocity of detonation can be measured with accuracy. Together with density it
4510-752: The factory at Immanuel Nobel's estate at Heleneborg . After this, Alfred founded the company Nitroglycerin Aktiebolaget in Vinterviken to continue work in a more isolated area and the following year moved to Germany, where he founded another company, Dynamit Nobel . Despite the invention of the blasting cap, the instability of nitroglycerin rendered it useless as a commercial explosive. To solve this problem, Nobel sought to combine it with another substance that would make it safe for transport and handling but would not reduce its effectiveness as an explosive. He tried combinations of cement, coal, and sawdust, but
4592-532: The first International Electrical Congress . The erg was adopted as its unit of energy in 1882. Wilhelm Siemens , in his inauguration speech as chairman of the British Association for the Advancement of Science (23 August 1882) first proposed the joule as unit of heat , to be derived from the electromagnetic units ampere and ohm , in cgs units equivalent to 10 erg . The naming of
4674-406: The first of several hundred patents , mostly concerning air pressure, gas and fluid gauges, but remained fascinated with nitroglycerin's potential as an explosive. Nobel, along with his father and brother Emil , experimented with various combinations of nitroglycerin and black powder. Nobel came up with a way to safely detonate nitroglycerin by inventing the detonator , or blasting cap, that allowed
4756-413: The first time in warfare. The Chinese would incorporate explosives fired from bamboo or bronze tubes known as bamboo firecrackers. The Chinese also inserted live rats inside the bamboo firecrackers; when fired toward the enemy, the flaming rats created great psychological ramifications—scaring enemy soldiers away and causing cavalry units to go wild. The first useful explosive stronger than black powder
4838-532: The history of chemical explosives lies in the history of gunpowder . During the Tang dynasty in the 9th century, Taoist Chinese alchemists were eagerly trying to find the elixir of immortality. In the process, they stumbled upon the explosive invention of black powder made from coal, saltpeter, and sulfur in 1044. Gunpowder was the first form of chemical explosives and by 1161, the Chinese were using explosives for
4920-743: The joule is defined as J = k g ⋅ m 2 ⋅ s − 2 = N ⋅ m = P a ⋅ m 3 = W ⋅ s = C ⋅ V {\displaystyle {\begin{alignedat}{3}\mathrm {J} \;&=~\mathrm {kg{\cdot }m^{2}{\cdot }s^{-2}} \\[0.7ex]&=~\mathrm {N{\cdot }m} \\[0.7ex]&=~\mathrm {Pa{\cdot }m^{3}} \\[0.7ex]&=~\mathrm {W{\cdot }s} \\[0.7ex]&=~\mathrm {C{\cdot }V} \\[0.7ex]\end{alignedat}}} One joule
5002-450: The manufacturing operations. A primary explosive is an explosive that is extremely sensitive to stimuli such as impact , friction , heat , static electricity , or electromagnetic radiation . Some primary explosives are also known as contact explosives . A relatively small amount of energy is required for initiation . As a very general rule, primary explosives are considered to be those compounds that are more sensitive than PETN . As
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#17327838445945084-436: The moisture content evaporates during detonation, cooling occurs, which reduces the temperature of reaction. Stability is also affected by the presence of moisture since moisture promotes decomposition of the explosive and, in addition, causes corrosion of the explosive's metal container. Explosives considerably differ from one another as to their behavior in the presence of water. Gelatin dynamites containing nitroglycerine have
5166-443: The molecule is said to have a zero oxygen balance. The molecule is said to have a positive oxygen balance if it contains more oxygen than is needed and a negative oxygen balance if it contains less oxygen than is needed. The sensitivity, strength , and brisance of an explosive are all somewhat dependent upon oxygen balance and tend to approach their maxima as oxygen balance approaches zero. A chemical explosive may consist of either
5248-457: The more important characteristics are listed below: Sensitivity refers to the ease with which an explosive can be ignited or detonated, i.e., the amount and intensity of shock , friction , or heat that is required. When the term sensitivity is used, care must be taken to clarify what kind of sensitivity is under discussion. The relative sensitivity of a given explosive to impact may vary greatly from its sensitivity to friction or heat. Some of
5330-454: The outside of the sticks, causing them to be even more sensitive to shock, friction, and temperature. Therefore, while the risk of an explosion without the use of a blasting cap is minimal for fresh dynamite, old dynamite is dangerous. Modern packaging helps eliminate this by placing the dynamite into sealed plastic bags and using wax-coated cardboard. Dynamite is moderately sensitive to shock. Shock resistance tests are usually carried out with
5412-590: The patents, and unlicensed duplicating companies were quickly shut down. A few American businessmen got around the patent by using absorbents other than diatomaceous earth, such as resin. Nobel originally sold dynamite as "Nobel's Blasting Powder" and later changed the name to dynamite, from the Ancient Greek word dýnamis ( δύναμις ), meaning "power". Dynamite is usually sold in the form of cardboard cylinders about 200 mm (8 in) long and about 32 mm ( 1 + 1 ⁄ 4 in) in diameter, with
5494-410: The possibility of such side reactions, condensation of steam, and aqueous solubility of gases like carbon dioxide. Oxygen balance is an expression that is used to indicate the degree to which an explosive can be oxidized. If an explosive molecule contains just enough oxygen to convert all of its carbon to carbon dioxide, all of its hydrogen to water, and all of its metal to metal oxide with no excess,
5576-466: The stabilizer and any additives). The maximum shelf life of nitroglycerin-based dynamite is recommended as one year from the date of manufacture under good storage conditions. Over time, regardless of the sorbent used, sticks of dynamite will "weep" or "sweat" nitroglycerin, which can then pool in the bottom of the box or storage area. For that reason, explosive manuals recommend the regular up-ending of boxes of dynamite in storage. Crystals will form on
5658-611: The successor organisation of the International Electrical Congress) adopted the " Giorgi system", which by virtue of assuming a defined value for the magnetic constant also implied a redefinition of the joule. The Giorgi system was approved by the International Committee for Weights and Measures in 1946. The joule was now no longer defined based on electromagnetic unit, but instead as the unit of work performed by one unit of force (at
5740-492: The sum of the masses of the two initial layers. There are applications where a shock wave, and electrostatics, can result in high velocity projectiles such as in an electrostatic particle accelerator . An explosion is a type of spontaneous chemical reaction that, once initiated, is driven by both a large exothermic change (great release of heat) and a large positive entropy change (great quantities of gases are released) in going from reactants to products, thereby constituting
5822-499: The test methods used to determine sensitivity relate to: Specific explosives (usually but not always highly sensitive on one or more of the three above axes) may be idiosyncratically sensitive to such factors as pressure drop, acceleration, the presence of sharp edges or rough surfaces, incompatible materials, or even — in rare cases — nuclear or electromagnetic radiation. These factors present special hazards that may rule out any practical utility. Sensitivity
5904-434: The time not yet named newton ) over the distance of 1 metre . The joule was explicitly intended as the unit of energy to be used in both electromagnetic and mechanical contexts. The ratification of the definition at the ninth General Conference on Weights and Measures , in 1948, added the specification that the joule was also to be preferred as the unit of heat in the context of calorimetry , thereby officially deprecating
5986-425: The two layers. As the length of time the shock wave spends at any point is small, we can see mixing of the two metals and their surface chemistries, through some fraction of the depth, and they tend to be mixed in some way. It is possible that some fraction of the surface material from either layer eventually gets ejected when the end of material is reached. Hence, the mass of the now "welded" bilayer, may be less than
6068-452: The unit in honour of James Prescott Joule (1818–1889), at the time retired but still living (aged 63), followed the recommendation of Siemens: Such a heat unit, if found acceptable, might with great propriety, I think, be called the Joule, after the man who has done so much to develop the dynamical theory of heat. At the second International Electrical Congress, on 31 August 1889, the joule
6150-414: The unit of energy the name joule , but has not given the unit of torque any special name, hence it is simply the newton-metre (N⋅m) – a compound name derived from its constituent parts. The use of newton-metres for torque but joules for energy is helpful to avoid misunderstandings and miscommunication. The distinction may be seen also in the fact that energy is a scalar quantity – the dot product of
6232-422: The use of the calorie . This is the definition declared in the modern International System of Units in 1960. The definition of the joule as J = kg⋅m ⋅s has remained unchanged since 1946, but the joule as a derived unit has inherited changes in the definitions of the second (in 1960 and 1967), the metre (in 1983) and the kilogram ( in 2019 ). One joule represents (approximately): 1 joule
6314-434: The world have enacted explosives laws and require licenses to manufacture, distribute, store, use, and possess explosives or ingredients. Explosive An explosive (or explosive material ) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light , heat , sound , and pressure . An explosive charge
6396-728: Was invented by Swedish chemist Alfred Nobel in 1866 and was the first safely manageable explosive stronger than black powder . Alfred Nobel's father, Immanuel Nobel , was an industrialist, engineer, and inventor. He built bridges and buildings in Stockholm and founded Sweden's first rubber factory. His construction work inspired him to research new methods of blasting rock that were more effective than black powder. After some bad business deals in Sweden, in 1838 Immanuel moved his family to Saint Petersburg , where Alfred and his brothers were educated privately under Swedish and Russian tutors. At
6478-799: Was nitroglycerin , developed in 1847. Since nitroglycerin is a liquid and highly unstable, it was replaced by nitrocellulose , trinitrotoluene ( TNT ) in 1863, smokeless powder , dynamite in 1867 and gelignite (the latter two being sophisticated stabilized preparations of nitroglycerin rather than chemical alternatives, both invented by Alfred Nobel ). World War I saw the adoption of TNT in artillery shells. World War II saw extensive use of new explosives (see: List of explosives used during World War II ) . In turn, these have largely been replaced by more powerful explosives such as C-4 and PETN . However, C-4 and PETN react with metal and catch fire easily, yet unlike TNT, C-4 and PETN are waterproof and malleable. The largest commercial application of explosives
6560-489: Was in operation in 1903 and by 1907 it was already producing 340,000 cases, 23 kilograms (50 lb) each, annually. A rival factory at Modderfontein was producing another 200,000 cases per year. There were two large explosions at the Somerset West plant during the 1960s. Some workers died, but the loss of life was limited by the modular design of the factory and its earth works, and the planting of trees that directed
6642-529: Was officially adopted alongside the watt and the quadrant (later renamed to henry ). Joule died in the same year, on 11 October 1889. At the fourth congress (1893), the "international ampere" and "international ohm" were defined, with slight changes in the specifications for their measurement, with the "international joule" being the unit derived from them. In 1935, the International Electrotechnical Commission (as
6724-643: Was unsuccessful. Finally, he tried diatomaceous earth , which is fossilized algae, that he brought from the Elbe River near his factory in Hamburg , which successfully stabilized the nitroglycerin into a portable explosive. Nobel obtained patents for his inventions in England on 7 May 1867 and in Sweden on 19 October 1867. After its introduction, dynamite rapidly gained wide-scale use as a safe alternative to black powder and nitroglycerin. Nobel tightly controlled
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