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112-652: A similar British plastic explosive, also based on RDX but with a plasticizer different from that used in Composition C-4, is known as PE-4 (Plastic Explosive No. 4). C-4 is a member of the Composition C family of chemical explosives. Variants have different proportions and plasticisers and include compositions C-2, C-3, and C-4. The original RDX-based material was developed by the British during World War II and redeveloped as Composition C when introduced to

224-613: A Figure of Insensitivity of exactly 80 (RDX defines the reference point). RDX sublimes in vacuum , which restricts or prevents its use in some applications. RDX, when exploded in air, has about 1.5 times the explosive energy of TNT per unit weight and about 2.0 times per unit volume. RDX is insoluble in water, with solubility 0.05975 g/L at temperature of 25 °C. The substance's toxicity has been studied for many years. RDX has caused convulsions (seizures) in military field personnel ingesting it, and in munition workers inhaling its dust during manufacture. At least one fatality

336-488: A hexahydro-1,3,5-triazine derivative. In laboratory settings (industrial routes are described below separately) it is obtained by treating hexamine with white fuming nitric acid . This nitrolysis reaction also produces methylene dinitrate, ammonium nitrate , and water as by-products. The overall reaction is: The conventional cheap nitration agent, called "mixed acid", cannot be used for RDX synthesis because concentrated sulfuric acid conventionally used to stimulate

448-432: A synthetic rubber ) as the binder , and 1.6% of a mineral oil often called "process oil". Instead of "process oil", low-viscosity motor oil is used in the manufacture of C-4 for civilian use. The British PE4 consists of 88.0% RDX, 1.0% pentaerythrite dioleate and 11.0% DG-29 lithium grease (corresp. to 2.2% lithium stearate and 8.8% mineral oil BP ) as the binder; a taggant (2,3-dimethyl-2,3-dinitrobutane, DMDNB )

560-448: A German citizen, rediscovered the explosive properties of RDX and applied for an Austrian patent in 1919, obtaining a British one in 1921 and an American one in 1922. All patents described the synthesis of the compound by nitrating hexamethylenetetramine . The British patent claims included the manufacture of RDX by nitration, its use with or without other explosives, its use as a bursting charge and as an initiator. The US patent claim

672-576: A Process for its Preparation" March 31, 1958, by the Phillips Petroleum Company . The Composition C-4 used by the United States Armed Forces contains 91% RDX ("Research Department Explosive", an explosive nitroamine ), bound by a mixture of 5.3% dioctyl sebacate (DOS) or dioctyl adipate (DOA) as the plasticizer (to increase the plasticity of the explosive), thickened with 2.1% polyisobutylene (PIB,

784-420: 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

896-471: A cooled mixture of hexamine and nitric acid in the nitrator. The RDX was purified and processed for its intended use; recovery and reuse of some methanol and nitric acid also was carried out. The hexamine-nitration and RDX purification plants were duplicated (i.e. twin-unit) to provide some insurance against loss of production due to fire, explosion, or air attack. The United Kingdom and British Empire were fighting without allies against Nazi Germany until

1008-634: 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

1120-427: A density of 1.80 g/cm is 8750 m/s. It starts to decompose at approximately 170 °C and melts at 204 °C. At room temperature , it is very stable. It burns rather than explodes. It detonates only with a detonator , being unaffected even by small arms fire. This property makes it a useful military explosive. It is less sensitive than pentaerythritol tetranitrate ( PETN ). Under normal conditions, RDX has

1232-619: A human child hospitalized in status epilepticus following the ingestion of 84.82 mg/kg dose of RDX (or 1.23 g for the patient's body weight of 14.5 kg) in the "plastic explosive" form. The substance has low to moderate toxicity with a possible human carcinogen classification. Further research is ongoing, however, and this classification may be revised by the United States Environmental Protection Agency (EPA). Remediating RDX-contaminated water supplies has proven to be successful. It

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1344-465: A large amount of binder in its composition. A series of shots were fired at vials containing C-4 in a test referred to as "the rifle bullet test". Only 20% of the vials burned, and none exploded. While C-4 passed the Army's bullet impact and fragment impact tests at ambient temperature, it failed the shock stimulus, sympathetic detonation and shaped charge jet tests. Additional tests were done including

1456-479: A light background. Relative numbers and positions of RDX particles have been measured from a series of 50 fingerprints left after a single contact impression. Military and commercial C-4 are blended with different oils. It is possible to distinguish these sources by analyzing this oil by high-temperature gas chromatography–mass spectrometry . The oil and plasticizer must be separated from the C-4 sample, typically by using

1568-602: A mixture of RDX, TNT, and aluminium, which had up to 50 percent more destructive power than TNT-filled depth charges. Considerable quantities of the RDX–TNT mixture were produced at the Holston Ordnance Works, with Tennessee Eastman developing an automated mixing and cooling process based around the use of stainless steel conveyor belts . A Semtex bomb was used in the Pan Am Flight 103 (known also as

1680-516: A non-polar organic solvent such as pentane followed by solid phase extraction of the plasticizer on silica. This method of analysis is limited by manufacturing variation and methods of distribution. U.S. soldiers during the Vietnam War era would sometimes use small amounts of C-4 as a fuel for heating rations, as it will burn unless detonated with a primary explosive . However, burning C-4 produces poisonous fumes, and soldiers are warned of

1792-433: 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

1904-685: 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

2016-399: 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

2128-735: 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,

2240-492: A stainless steel mixing kettle. This is called the aqueous slurry-coating process. The kettle is tumbled to obtain a homogeneous mixture. This mixture is wet and must be dried after transfer to drying trays. Drying with forced air for 16 hours at 50 °C to 60 °C is recommended to eliminate excess moisture. C-4 produced for use by the U.S. military, commercial C-4 (also produced in the United States), and PE-4 from

2352-618: 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

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2464-709: 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

2576-427: 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

2688-581: Is a rectangular block of Composition C-4 about 2 by 1.5 inches (51 mm × 38 mm) and 11 inches (280 mm) long, weighing 1.25 lb (570 g). The M112 is wrapped in a sometimes olive color Mylar -film container with a pressure-sensitive adhesive tape on one surface. The M112 demolition blocks of C-4 are commonly manufactured into the M183 "demolition charge assembly", which consists of 16 M112 block demolition charges and four priming assemblies packaged inside military Carrying Case M85. The M183

2800-526: Is added at a minimum of 0.10% weight of the plastic explosive, typically at 1.0% mass. The newer PE7 consists of 88.0% RDX, 1.0% DMDNB taggant and 11.0% of a binder composed of low molecular mass hydroxyl-terminated polybutadiene , along with an antioxidant and an agent preventing hardening of the binder upon prolonged storage. The PE8 consists of 86.5% RDX, 1.0% DMDNB taggant and 12.5% of a binder composed of di(2-ethylhexyl) sebacate thickened with high molecular mass polyisobutylene. Technical data according to

2912-402: 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

3024-440: 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

3136-520: 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

3248-410: Is believed to be the explosive used in the 2010 Moscow Metro bombings . Traces of RDX were found on pieces of wreckage from 1999 Russian apartment bombings and 2004 Russian aircraft bombings . FSB reports on the bombs used in the 1999 apartment bombings indicated that while RDX was not a part of the main charge, each bomb contained plastic explosive used as a booster charge . Ahmed Ressam ,

3360-491: Is believed to have been used in many bomb plots, including terrorist plots. RDX is the base for a number of common military explosives: Outside military applications, RDX is also used in controlled demolition to raze structures. The demolition of the Jamestown Bridge in the U.S. state of Rhode Island was one instance where RDX shaped charges were used to remove the span. RDX is classified by chemists as

3472-564: Is classified as a nitroamine alongside HMX , which is a more energetic explosive than TNT . It was used widely in World War II and remains common in military applications . RDX is often used in mixtures with other explosives and plasticizers or phlegmatizers (desensitizers); it is the explosive agent in C-4 plastic explosive and a key ingredient in Semtex . It is stable in storage and

C-4 (explosive) - Misplaced Pages Continue

3584-602: Is considered one of the most energetic and brisant of the military high explosives , with a relative effectiveness factor of 1.60. RDX is also less commonly known as cyclonite , hexogen (particularly in Russian, French and German-influenced languages), T4 , and, chemically, as cyclotrimethylene trinitramine . In the 1930s, the Royal Arsenal , Woolwich , started investigating cyclonite to use against German U-boats that were being built with thicker hulls. The goal

3696-443: 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

3808-450: Is essentially nonhygroscopic . The shock sensitivity of C-4 is related to the size of the nitramine particles. The finer they are the better they help to absorb and suppress shock. Using 3-nitrotriazol-5-one (NTO), or 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) (available in two particle sizes (5 μm, 40 μm)), as a substitute for RDX, is also able to improve stability to thermal, shock, and impact/friction stimulus; however, TATB

3920-452: 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

4032-472: 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

4144-408: Is known to be a kidney toxin in humans and highly toxic to earthworms and plants, thus army testing ranges where RDX was used heavily may need to undergo environmental remediation. Concerns have been raised by research published in late 2017 indicating that the issue has not been addressed correctly by U.S. officials. RDX has been used as a rodenticide because of its toxicity. RDX is degraded by

4256-465: Is not cost-effective, and NTO is more difficult to use in the manufacturing process. C-4 has toxic effects on humans when ingested. Within a few hours multiple generalized seizures, vomiting, and changes in mental activity occur. A strong link to central nervous dysfunction is observed. If ingested, patients may be administered a dose of active charcoal to adsorb some of the toxins, and haloperidol intramuscularly and diazepam intravenously to help

4368-400: 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

4480-471: Is that it can easily be molded into any desired shape to change the direction of the resulting explosion. C-4 has high cutting ability. For example, the complete severing of a 36-centimetre (14 in) deep I-beam takes between 680 and 910 g (1.50 and 2.01 lb) of C-4 when properly applied in thin sheets. Military grade C-4 is commonly packaged as the M112 demolition block. The demolition charge M112

4592-473: 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

C-4 (explosive) - Misplaced Pages Continue

4704-411: 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

4816-424: Is used to breach obstacles or demolish large structures where larger satchel charges are required. Each priming assembly includes a five-or-twenty-foot (1.5 or 6.1 m) length of detonating cord assembled with detonating cord clips and capped at each end with a booster. When the charge is detonated, the explosive is converted into compressed gas. The gas exerts pressure in the form of a shock wave, which demolishes

4928-407: 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

5040-533: Is very stable and insensitive to most physical shocks. C-4 cannot be detonated by a gunshot or by dropping it onto a hard surface. It does not explode when set on fire or exposed to microwaves . Detonation can be initiated only by a shockwave , such as when a detonator inserted into it is fired. When detonated, C-4 rapidly decomposes to release nitrogen, water and carbon oxides as well as other gases. The detonation proceeds at an explosive velocity of 8,092 m/s (26,550 ft/s). A major advantage of C-4

5152-690: The Bureau of Mines , Bruceton, Pennsylvania , using Office of Scientific Research and Development (OSRD) funding. In 1941, the UK's Tizard Mission visited the US Army and Navy departments and part of the information handed over included details of the "Woolwich" method of manufacture of RDX and its stabilisation by mixing it with beeswax . The UK was asking that the US and Canada, combined, supply 220 short tons (200 t) (440,000 lb) of RDX per day. A decision

5264-500: The Department of the Army for the Composition C-4 follows. C-4 is manufactured by combining the above ingredients with binders dissolved in a solvent . Once the ingredients have been mixed, the solvent is extracted through drying and filtering. The final material is a solid with a dirty white to light brown color, a putty-like texture similar to modeling clay, and a distinct smell of motor oil. Depending on its intended usage and on

5376-639: The Kenyan Police , the Iranians planned to use the RDX for "attacks on Israeli, US, UK and Saudi Arabian targets". RDX was used in the assassination of Lebanese Prime Minister Rafic Hariri on February 14, 2005. In the 2019 Pulwama attack in India, 250 kg of high-grade RDX was used by Jaish-e-Mohammed . The attack resulted in the deaths of 44 Central Reserve Police Force (CRPF) personnel as well as

5488-620: The Philadelphia Police Department dropped a C-4 bomb on the home of the MOVE organization , killing eleven people — including five children — and wiping out 61 homes in two city blocks. Composition C-4 is recommended in al-Qaeda 's traditional curriculum of explosives training. In October 2000, the group used C-4 to attack the USS Cole , killing 17 sailors. In 1996, Saudi Hezbollah terrorists used C-4 to blow up

5600-598: The al-Qaeda Millennium Bomber , used a small quantity of RDX as one of the components in the bomb that he prepared to detonate in Los Angeles International Airport on New Year's Eve 1999–2000; the bomb could have produced a blast forty times greater than that of a devastating car bomb . In July 2012, the Kenyan government arrested two Iranian nationals and charged them with illegal possession of 15 kilograms (33 pounds) of RDX. According to

5712-502: The nitronium ion formation decomposes hexamine into formaldehyde and ammonia. Modern syntheses employ hexahydro triacyl triazine as it avoids formation of HMX. RDX was used by both sides in World War II . The US produced about 15,000 long tons (15,000 t) per month during WWII and Germany about 7,100 tonnes (7,000 long tons) per month. RDX had the major advantages of possessing greater explosive force than TNT and required no additional raw materials for its manufacture. Thus, it

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5824-607: The "combination process" by combining the Ross and Schiessler process used in Canada (aka the German E-method) with direct nitration. The combination process required large quantities of acetic anhydride instead of nitric acid in the old British "Woolwich process". Ideally, the combination process could produce two moles of RDX from each mole of hexamethylenetetramine. The expanded production of RDX could not continue to rely on

5936-461: The "pendulum friction test", which measured a five-second explosion temperature of 263 °C to 290 °C. The minimum initiating charge required is 0.2 grams of lead azide or 0.1 grams of tetryl . The results of 100 °C heat test are: 0.13% loss in the first 48 hours, no loss in the second 48 hours, and no explosions in 100 hours. The vacuum stability test at 100 °C yields 0.2 cubic centimeters of gas in 40 hours. Composition C-4

6048-588: The Khobar Towers , a U.S. military housing complex in Saudi Arabia . Composition C-4 has also been used in improvised explosive devices by Iraqi insurgents . RDX RDX (abbreviation of " Research Department eXplosive " or Royal Demolition eXplosive ) or hexogen , among other names, is an organic compound with the formula (CH 2 N 2 O 2 ) 3 . It is white, odorless, and tasteless, widely used as an explosive . Chemically, it

6160-519: The Lockerbie) bombing in 1988. A belt laden with 700 g (1.5 lb) of RDX explosives tucked under the dress of the assassin was used in the assassination of former Indian prime minister Rajiv Gandhi in 1991. The 1993 Bombay bombings used RDX placed into several vehicles as bombs. RDX was the main component used for the 2006 Mumbai train bombings and the Jaipur bombings in 2008. It also

6272-695: The Ross and Schiessler process described below. The KA-method, also developed by Knöffler, turned out to be identical to the Bachmann process described below. The explosive shells fired by the MK 108 cannon and the warhead of the R4M rocket , both used in Luftwaffe fighter aircraft as offensive armament, both used hexogen as their explosive base. In the United Kingdom (UK), RDX was manufactured from 1933 by

6384-427: The U.S. military. It was replaced by Composition C-2 around 1943 and later redeveloped around 1944 as Composition C-3. The toxicity of C-3 was reduced, the concentration of RDX was increased, giving it improved safety during usage and storage. Research on a replacement for C-3 was begun prior to 1950, but the new material, C-4, did not begin pilot production until 1956. C-4 was submitted for patent as "Solid Propellant and

6496-629: The US). A different method of production to the Woolwich process was found and used in Canada, possibly at the McGill University department of chemistry. This was based on reacting paraformaldehyde and ammonium nitrate in acetic anhydride . A UK patent application was made by Robert Walter Schiessler (Pennsylvania State University) and James Hamilton Ross (McGill, Canada) in May 1942; the UK patent

6608-467: The United Kingdom each have their own unique properties and are not identical. The analytical techniques of time-of-flight secondary ion mass spectrometry and X-ray photoelectron spectroscopy have been demonstrated to discriminate finite differences in different C-4 sources. Chemical, morphological structural differences, and variation in atomic concentrations are detectable and definable. C-4

6720-562: The Western Cartridge Company, E. I. du Pont de Nemours & Company, and Tennessee Eastman Company , part of Eastman Kodak. At the Eastman Chemical Company (TEC), a leading manufacturer of acetic anhydride, Werner Emmanuel Bachmann developed a continuous-flow process for RDX utilizing an ammonium nitrate/nitric acid mixture as a nitrating agent in a medium of acetic acid and acetic anhydride. RDX

6832-479: The Woolwich process, were producing 25,000 short tons (23,000 t) (50 million pounds) of Composition B per month. The Bachmann process yields both RDX and HMX , with the major product determined by the specific reaction conditions. The United Kingdom's intention in World War II was to use "desensitised" RDX. In the original Woolwich process, RDX was phlegmatized with beeswax, but later paraffin wax

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6944-413: 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

7056-529: The attacker. Two letter bombs sent to journalists in Ecuador were disguised as USB flash drives which contained RDX that would detonate when plugged in. RDX has a high nitrogen content and a high oxygen to carbon ratio, (O:C ratio), both of which indicate its explosive potential for formation of N 2 and CO 2 . RDX undergoes a deflagration to detonation transition (DDT) in confinement and certain circumstances. The velocity of detonation of RDX at

7168-479: 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

7280-486: The chemical reaction moves faster through the material than 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;

7392-425: 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,

7504-543: The compound more closely and in June 1916 filed two patent applications, one for its use in smokeless propellants and another for its use as an explosive, noting its excellent characteristics. The German military hadn't considered its adoption during the war due to the expense of production but started investigating its use in 1920, referring to it as hexogen. Research and development findings were not published further until Edmund von Herz, described as an Austrian and later

7616-437: The compound. However, positive results are highly variable and the mass of RDX can range between 1.7 and 130  ng , each analysis must be individually handled using magnifying equipment. The cross polarized light images obtained from microscopic analysis of the fingerprint are analyzed with gray-scale thresholding to improve contrast for the particles. The contrast is then inverted in order to show dark RDX particles against

7728-565: The dangers of personal injury when using the plastic explosive. Among field troops in Vietnam it became common knowledge that ingestion of a small amount of C-4 would produce a " high " similar to that of ethanol. Others would ingest C-4, commonly obtained from a Claymore mine , to induce temporary illness in the hope of being sent on sick leave. Terrorist groups have used C-4 worldwide in acts of terrorism and insurgency, as well as domestic terrorism and state terrorism . On May 13, 1985,

7840-421: 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

7952-460: The director of Royal Ordnance Factories , Explosives. RDX was widely used during World War II , often in explosive mixtures with TNT such as Torpex , Composition B , Cyclotols, and H6. RDX was used in one of the first plastic explosives . The bouncing bomb depth charges used in the " Dambusters Raid " each contained 6,600 pounds (3,000 kg) of Torpex; The Tallboy and Grand Slam bombs designed by Barnes Wallis also used Torpex. RDX

8064-498: 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

8176-604: 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

8288-492: The explosive chemical reaction. Small particles of C-4 may be easily identified by mixing with thymol crystals and a few drops of sulfuric acid . The mixture will become rose colored upon addition of a small quantity of ethyl alcohol. RDX has a high birefringence , and the other components commonly found in C-4 are generally isotropic ; this makes it possible for forensic science teams to detect trace residue on fingertips of individuals who may have recently been in contact with

8400-445: 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

8512-651: 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

8624-442: 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

8736-414: 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,

8848-409: 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

8960-429: 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

9072-413: 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

9184-546: The fumes, or due to ingestion, made possible by many small particles adhering to the knife having been deposited into the cooked food. The symptom complex involved nausea, vomiting, generalized seizures, and prolonged postictal confusion and amnesia; which indicated toxic encephalopathy . Oral toxicity of RDX depends on its physical form; in rats, the LD50 was found to be 100 mg/kg for finely powdered RDX, and 300 mg/kg for coarse, granular RDX. A case has been reported of

9296-532: 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

9408-489: The manufacturer, there are differences in the composition of C-4. For example, a 1990 U.S. Army technical manual stipulated that Class IV composition C-4 consists of 89.9±1% RDX, 10±1% polyisobutylene, and 0.2±0.02% dye that is itself made up of 90% lead chromate and 10% lamp black . RDX classes A, B, E, and H are all suitable for use in C-4. Classes are measured by granulation. The manufacturing process for Composition C-4 specifies that wet RDX and plastic binder are added in

9520-450: 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

9632-504: The methanol was converted to formaldehyde and some of the ammonia converted to nitric acid, which was concentrated for RDX production. The rest of the ammonia was reacted with formaldehyde to produce hexamine. The hexamine plant was supplied by Imperial Chemical Industries . It incorporated some features based on data obtained from the United States (US). RDX was produced by continually adding hexamine and concentrated nitric acid to

9744-625: The middle of 1941 and had to be self-sufficient . At that time (1941), the UK had the capacity to produce 70 long tons (71 t) (160,000 lb) of RDX per week; both Canada , an allied country and self-governing dominion within the British Empire, and the US were looked upon to supply ammunition and explosives, including RDX. By 1942 the Royal Air Force 's annual requirement was forecast to be 52,000 long tons (53,000 t) of RDX, much of which came from North America (Canada and

9856-436: 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

9968-443: 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

10080-457: 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

10192-412: The organisms in sewage sludge as well as the fungus Phanaerocheate chrysosporium . Both wild and transgenic plants can phytoremediate explosives from soil and water. Explosive material#Stability 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

10304-577: The patient control seizures until it has passed. However, ingesting small amounts of C-4 is not known to cause any long-term impairment. If C-4 is marked with a taggant , such as DMNB , it can be detected with an explosive vapor detector before it has been detonated. A variety of methods for explosive residue analysis may be used to identify C-4. These include optical microscope examination and scanning electron microscopy for unreacted explosive, chemical spot tests, thin-layer chromatography , X-ray crystallography , and infrared spectroscopy for products of

10416-410: 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,

10528-426: The production of light , heat , sound , and pressure . An explosive charge 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

10640-656: The research department in a pilot plant at the Royal Arsenal in Woolwich, London , a larger pilot plant being built at the RGPF Waltham Abbey just outside London in 1939. In 1939 a twin-unit industrial-scale plant was designed to be installed at a new 700-acre (280 ha) site, ROF Bridgwater , away from London and production of RDX started at Bridgwater on one unit in August 1941. The ROF Bridgwater plant brought in ammonia and methanol as raw materials:

10752-627: The same viewpoint and wanted to continue using TNT. RDX had been tested by Picatinny Arsenal in 1929, and it was regarded as too expensive and too sensitive. The Navy proposed to continue using ammonium picrate . In contrast, the National Defense Research Committee (NDRC), who had visited The Royal Arsenal, Woolwich, thought new explosives were necessary. James B. Conant , chairman of Division B, wished to involve academic research into this area. Conant therefore set up an experimental explosives research laboratory at

10864-492: 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

10976-406: The target by cutting, breaching, or cratering. Other forms include the mine-clearing line charge and M18A1 Claymore Mine . Composition C-4 exists in the U.S. Army Hazardous Components Safety Data Sheet on sheet number 00077. Impact tests done by the U.S. military indicate composition C-4 is less sensitive than composition C-3 and is fairly insensitive. The insensitivity is attributed to using

11088-499: 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

11200-425: 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

11312-564: The use of natural beeswax to desensitize the explosive as in the original British composition (RDX/BWK-91/9). A substitute stabilizer based on petroleum was developed at the Bruceton Explosives Research Laboratory in Pennsylvania, with the resulting explosive designated Composition A-3. The National Defence Research Committee (NDRC) instructed three companies to develop pilot plants. They were

11424-453: The various chemical routes to RDX. The W-method was developed by Wolfram in 1934 and gave RDX the code name "W-Salz". It used sulfamic acid , formaldehyde, and nitric acid. SH-Salz (SH salt) was from Schnurr, who developed a batch-process in 1937–38 based on nitrolysis of hexamine. The K-method, from Knöffler, involved addition of ammonium nitrate to the hexamine/nitric acid process. The E-method, developed by Ebele, proved to be identical to

11536-768: The world. The Woolwich process was expensive: it needed 11 pounds (5.0 kg) of strong nitric acid for every pound of RDX. By early 1941, the NDRC was researching new processes. The Woolwich or direct nitration process has at least two serious disadvantages: (1) it used large amounts of nitric acid and (2) at least one-half of the formaldehyde is lost. One mole of hexamethylenetetramine could produce at most one mole of RDX. At least three laboratories with no previous explosive experience were instructed to develop better production methods for RDX; they were based at Cornell , Michigan , and Pennsylvania State universities. Werner Emmanuel Bachmann , from Michigan, successfully developed

11648-799: 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

11760-684: Was also extensively used in World War I RDX was reported in 1898 by Georg Friedrich Henning (1863-1945), who obtained a German patent for its manufacture by nitrolysis of hexamine ( hexamethylenetetramine ) with concentrated nitric acid. In this patent, only the medical properties of RDX were mentioned. During WWI , Heinrich Brunswig (1865-1946) at the private military-industrial laboratory Zentralstelle für wissenschaftlich-technische Untersuchungen  [ de ] (Center for Scientific-Technical Research) in Neubabelsberg studied

11872-468: Was attributed to RDX toxicity in a European munitions manufacturing plant. During the Vietnam War , at least 40 American soldiers were hospitalized with composition C-4 (which is 91% RDX) intoxication from December 1968 to December 1969. C-4 was frequently used by soldiers as a fuel to heat food, and the food was generally mixed by the same knife that was used to cut C-4 into small pieces prior to burning. Soldiers were exposed to C-4 either due to inhaling

11984-563: Was crucial to the war effort and the current batch-production process was too slow. In February 1942, TEC began producing small amounts of RDX at its Wexler Bend pilot plant, which led to the US government authorizing TEC to design and build Holston Ordnance Works (H.O.W.) in June 1942. By April 1943, RDX was being manufactured there. At the end of 1944, the Holston plant and the Wabash River Ordnance Works , which used

12096-515: Was for the use of a hollow explosive device containing RDX and a detonator cap containing it. Herz was also the first to identify the cyclic nature of the molecule. In the 1930s, Germany developed improved production methods. During World War II, Germany used the code names W Salt, SH Salt, K-method, the E-method, and the KA-method. These names represented the identities of the developers of

12208-760: Was issued in December 1947. Gilman states that the same method of production had been independently discovered by Ebele in Germany prior to Schiessler and Ross, but that this was not known by the Allies. Urbański provides details of five methods of production, and he refers to this method as the (German) E-method. At the beginning of the 1940s, the major US explosive manufacturers, E. I. du Pont de Nemours & Company and Hercules , had several decades of experience of manufacturing trinitrotoluene (TNT) and had no wish to experiment with new explosives. US Army Ordnance held

12320-492: Was taken by William H. P. Blandy , chief of the Bureau of Ordnance , to adopt RDX for use in mines and torpedoes . Given the immediate need for RDX, the US Army Ordnance, at Blandy's request, built a plant that copied the equipment and process used at Woolwich. The result was the Wabash River Ordnance Works run by E. I. du Pont de Nemours & Company. At that time, this works had the largest nitric acid plant in

12432-446: Was to develop an explosive more energetic than TNT . For security reasons, Britain termed cyclonite "Research Department Explosive" (R.D.X.). The term RDX appeared in the United States in 1946. The first public reference in the United Kingdom to the name RDX , or R.D.X. , to use the official title, appeared in 1948; its authors were the managing chemist, ROF Bridgwater , the chemical research and development department, Woolwich, and

12544-443: Was used, based on the work carried out at Bruceton. In the event the UK was unable to obtain sufficient RDX to meet its needs, some of the shortfall was met by substituting amatol , a mixture of ammonium nitrate and TNT. Karl Dönitz was reputed to have claimed that "an aircraft can no more kill a U-boat than a crow can kill a mole ". Nonetheless, by May 1942 Wellington bombers began to deploy depth charges containing Torpex ,

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