Explosives - Compositions
In general, high explosives are compositions and mixtures of ingredients capable of instantaneously releasing large amounts of energy and doing work of various kinds on objects and bodies surrounding them. In some cases the useful work that is done is limited only by the energy content of the explosive composition, while in other cases the transfer of energy from the explosive composition to surrounding bodies is controlled to a large degree by the momentum or impulse released by the detonating explosive.
Amatol
Research and development during World War I yielded amatol (TNT plus ammonium nitrate), an explosive with three times the power of gunpowder. Amatol consists of TNT and ammonium nitrate mixed in either 20 /80 or 50 /50 ratios. When the U.S. entered the war, Amatol was adopted for loading high explosive shells. Owing to shortages of TNT and RDX (cyclonite) most World War II mines had had 50/50 ammonium nitrate and TNT (amatol) warheads. This was a low quality explosive but was later improved by the addition of about 20% aluminum to produce minol.
This explosive is a mechanical mixture of Ammonium Nitrate and TNT. It is crystalline and yellow or brownish, moisture-absorbing, insensitive to friction, but may be detonated by severe impact. It is readily detonated by Mercury Fulminate and other high explosives. Amatol 50/50 has approximately the same rate of detonation and brisance as TNT. Amatol 80/20 (used in Bangalore Torpedoes), produces white smoke on detonation, while Amatol 50/50 produces a smoke, less black than straight TNT. Amatol is used as a substitute for TNT and is to be mainly found in large caliber shells.
Driven by its liquid propellant engine, the V-2 had a range of approximately 200 miles. Its warhead consisted of 2,000 pounds of amatol.
Baratol
Baratol is a composition of barium nitrate and TNT. TNT is typically 25-33% of the mixture with 1% wax as a binder. The high density of barium nitrate gives baratol a density of at least 2.5.
Early implosion atomic bombs, like the Gadget exploded at Trinity in 1945, the Soviet's Joe 1 in 1949, or India in 1972, used an Composition-B [RDX-TNT mixture] as the fast explosive, with baratol used as the slow explosive.
Composition A
Composition A is a was-coated, granular explosive consisting of RDX and plasticizing was. Composition A is used by the military in land mines and 2.75 and 5 inch rockets. Comp A-3 explosives are made from RDX and wax. Composition A-3 is a wax-coated, granular explosive, consisting of 91% RDX and 9% desensitizing wax. Composition A-3 is not melted or cast. It is pressed into projectiles. It is nonhygroscopic and possesses satisfactory stowage properties. Composition A-3 is appreciably more brisant and powerful than TNT; its velocity of detonation is approximately 27,000 fps. It may be white or buff, depending upon the color of the wax used to coat the powdered RDX. Composition A-3 is used as a fillerinprojectiles that contain a small burster cavity, such as antiaircraft projectiles. It can be used as compressed fillers for medium-caliber projectiles.
Composition B / Comp B
Comp B explosives are made from TNT, RDX, and wax, such as 59.5 percent RDX, 39.5 percent TNT and 1 percent wax. Desensitizing agents are added. Composition B is used by the military in land mines, rockets and projectiles. Cast Composition B has a specific gravity of 1.65 and a detonation velocity of 'about 25,000 fps and is used as a primer and booster for blasting agents.
Composition B is a mixture of 59% RDX, 40% TNT, and 1% wax. The TNT reduces the sensitivity of the RDX to a safe degree and, because of its melting point, allows the material to be cast-loaded. The blast energy of Composition B is slightly higher than that of TNT. Composition B is nonhygroscopic and remains stable in stowage. It has an extremely high-shaped-charge efficiency. The velocity of detonation is approximately 24,000 fps, and its color ranges from yellow to brown. Composition B has been used as a more powerful replacement for TNT in loading some of the rifle grenades and some rocket heads. It can be used where an explosive with more power and brisance is of tactical advantage and there is no objection to a slight increase of sensitivity. While no longer used in newer gun projectiles, some older stocks may be found with Composition B main charges.
Factors for Equivalent Weight of Composition B Explosive Equivalent Factor Comp B 1.00 PBXN-109 1.19 Tritonal 1.09 AFX-777 1.47 AFX-757 1.39 PAX-28 1.62
Composition B-3
During the development of a series of melt-castable explosive formulations devoid of TNT, non-TNT formulations yielded self-heating temperatures significantly lower than predicted. In other tests, Composition B (59.5% RDX, 39.5% TNT, 1% wax) demonstrated an exceedingly low self-heating temperature that ultimately results in a violent final reaction. It is often processed above its self-heating temperature, yet it is safely processed in 300-gallon melt kettles. Researchers subjected Composition B and its individual energetic components to one-liter cook-off testing. They expanded their investigations to include neat TNT, neat RDX (HRDX), an insensitive RDX (IRDX) essentially absent of microinclusions and voids, and Composition B-3 (60% RDX, 40% TNT) made with IRDX. Following analysis of these tests, researchers also tested an HRDX/TNT (13% HRDX, 87% TNT) mixture.
Neat TNT is thermally destabilized by the presence of RDX, either HRDX or IRDX, indicating that RDX is the trigger in the thermal decomposition process associated with Composition B (HRDX) and Composition B-3 (IRDX). The reaction violence of both neat HRDX and Composition B made with HRDX were exceedingly violent, with either partial detonation or detonation occurring. Additionally, researchers observed that the reaction of Composition B-3 (IRDX/TNT) was more violent than either neat TNT or neat IRDX. Once again, they hypothesized that solubilized RDX in molten TNT was the source of the effect. They believe the high-quality, defect-free crystals of IRDX were modified by a dynamic equilibrium in molten TNT, with IRDX solubilized and reprecipitated as ill-defined, voided crystals similar to HRDX. They suspect these ill-defined RDX crystallites present at cook-off temperatures were the source of the reaction violence at cook-off.
Composition C-3
Compositior C-3 is one of the Composition C series that has now been replaced by C-4, especially for loading shaped charges. However, quantities of Composition C-1 and Composition C-2 may be found in the field. Composition C-1 is 88.3% RDX and 11.7% plasticizing oil. Composition C-3 is 77% RDX, 3% tetryl, 4% TNT, 1% NC, 5% MNT (mononitrotoluol), and 10% DNT (dinitrotoluol). The last two compounds, while they are explosives, are oily liquids and plasticize the mixture. The essential difference between Composition C-3 and Composition C-2 is the substitution of 3% tetryl for 3% RDX, which improves the plastic qualities. The changes were made in an effort to obtain a plastic, puttylike composition to meet the requirements of an ideal explosive for molded and shaped charges that will maintain its plasticity over a wide range of temperatures and not exude oil.
Composition C-3 is about 1.35 times as powerful as TNT. The melting point of Composition C-3 is 68°C, and it is soluble in acetone. The velocity of detonation is approximate y 26,000 fps. Its color is light brown. As with Composition B, Composition C is no longer being used as a gun projectile main charge. However, some stocks may still be in service with Composition C-3 used as a main charge.
Composition C-4 / Comp C-4 Plastic Explosive
The plasticized form of RDX, composition C-4, contains 91% RDX, 2.1% polyisobutylene, 1.6% motor oil, and 5.3% 2-ethylhexyl sebacate.
The Demolition charge M183 is used primarily in breaching obstacles or demolition of large structures where large charges are required (Satchel Charge). The charge assembly M183 consists of 16 block demolition charges M112, four priming assemblies and carrying case M85. Each Priming assembly consists of a five-foot length of detonating cord assembled with two detonating cord clips and capped at each end with a booster. The components of the assembly are issued in the carrying case. The demolition charge M112 is a rectangular block of Composition C-4 approximately 2 inches by 1.5 inches and 11 inches long, weighing 1.25 Lbs. 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 the target by cutting, breaching, or cratering.
Using explosives provides the easiest and fastest way to break the frozen ground. However, the use of demolitions will be restricted when under enemy observation. Composition C-4, tetrytol, and TNT are the best explosives for use in northern operations because they retain their effectiveness in cold weather. Dig a hole in the ground in which to place the explosive and tamp the charge with any material available to increase its effectiveness. Either electric or nonelectric circuits may be used to detonate the charge. For a foxhole, 10 pounds of explosive will usually be sufficient. Another formula is to use 2 pounds of explosive for every 30 cm (1') of penetration in frozen ground.
DMDNB (2-3 dimethyl, 2-3 dinitrobutane) is a new, military unique compound used as a tagant in C-4 explosive. Therefore there is no OSHA or ACGIH standard. However, USACHPPM's Toxicology Directorate did a study to determine an Army Exposure Limit. There is no toxicological data for DMDNB's effects on the human body, but tests were done on laboratory animals and they showed a reversible liver hypertrophy in rats that were exposed to DMDNB. An exposure level was determined and a one thousand fold safety factor was used to lower the Army exposure level to 0.15 mg/m^3. (At this level there are no warning properties, i.e. smell, taste, etc.)
Composition H6 / COMP H6
H-6 is an Australian produced explosive composition. Composition H6 is a widely used main charge filling for underwater blast weapons such as mines, depth charges, torpedoes and mine disposal charges. The M21 AT mine is 230 millimeters in diameter and 206 millimeters high. It weighs 7.6 kilograms and has 4.95 kilograms of Composition H6 explosive.
In weapon applications, computational models require experimental data to determine certain specific output parameters of H6 to predict various underwater blast scenarios. To this end, the critical diameter dc, which is the minimum diameter which will sustain a stable detonation, and the limiting value of the velocity of detonation at infinite charge diameter D-infinity, were determined for unconfined cylinders of H6.
Cyclotol [Composition B]
Cyclotol, which is a mixture of RDX and TNT, is an explosive used in shaped charge bombs.
CXM-6
On 30 August 1999 Holston Army Ammunition Plant restarted production of new explosives to fill an order for Composition CXM-3. This is the first new explosive production by Royal Ordnance North America (RONA) as the operating contractor at Holston. CXM-3 will be supplied to Atlantic Research Corporation to fill warheads for the Tomahawk missile system. RONA is also planning to produce other RDX and HMX products, including approximately 800,000 pounds of Composition C-4, by the end of December.
Detasheet
Detasheet is a plastic explosives, manufactured by DuPont containing PETN with nitrocellulose and a binder. It is manufactured in thin flexible sheets with a rubbery texture, and is generally coloured either reddish/orange (commercial) or green (military). In use, it is typically cut to shape for precision engineering charges.
Dynamite
In 1847 a new explosive came into being. This was nitroglycerine, made by treating glycerine with nitric and sulphuric acids. But at first it was even more dangerous to handle than guncotton, for the least shock exploded it, and its violence was terrific. The great chemist Alfred Nobel tried to improve it by mixing it with gunpowder, but the powder did not absorb all the nitroglycerine, and accidents of the most terrible kind became more and more frequent. Yet the new explosive, being liquid, could be poured into crevices in rocks, and was so useful as a blasting agent that its manufacture went on until a large vessel carrying cases of the explosive from Hamburg to Chili blew up at sea. The ship was blown to bits and her crew killed, and the disaster caused so great a sensation that the manufacture of nitroglycerine was prohibited in Sweden, Belgium, and in England. But Nobel still continued his experiments, and at last, after trying sawdust and all other sorts of absorbents in vain, found the perfect absorbent in the shape of keiselguhr-a sort of earth made of fossil shells. The mixture is what we know to-day as dynamite; and in spite of the fact that modern chemistry has produced very many new explosives, some of terrific power, dynamite remains the safest and most widely used of all explosives.
Many attempts have been made to use dynamite in guns; and the Americans at one time built some huge air guns for the purpose of firing large shells, or rather aerial torpedoes, charged with dynamite. But these guns, of which one or two were used in the Spanish-American War, were very cumbersome and slow in use. Nor could they throw a projectile to a greater distance than a mile. So they were soon abandoned in favor of rifled cannon-firing shells loaded with explosives such as cordite or lyddite.
Dynamite was originally a mixture of nitroglycerin and diato-mite, a porous, inert silica. Today, straight nitroglycerin dynamite consists of nitroglycerin, with sodium nitrate, antacid, carbonaceous fuel, and sometimes sulfur in place of the inert filler. It is most commonly manufactured in weight strengths of 20 to 60 percent. Because of the tendency of nitroglycerin to freeze at low working temperature, another explosive oil usually replaces part of the nitroglycerin in a straight dynamite.
Straight dynamite has a high detonation velocity which gives a shattering action. It resists water well in the higher grades but poorly in the lower grades. Straight dynamite generally has poor fume qualities, and is unsuitable for use underground or in poorly ventilated spaces. The use of straight dynamite has declined because of high cost, sensitivity to shock and friction, and high flammability. Ammonia ("extra") dynamites have replaced straight dynamite in most applications.
Ditching dynamite is a name given to 50 percent straight dynamite. Its high sensitivity is advantageous in ditching where sympathetic detonation eliminates the need for caps or detonating fuse with individual charges. Sixty percent straight dynamite is sometimes packaged in special cartridges for uncle rwater work.
Ammonia dynamites (extra dynamite) are the most widely used cartridge explosives. An ammonia dynamite is similar to a straight dpmite except that ammonium nitrate replaces a portion of the nitroglycerin and sodium nitrate. High-density ammonia dynamite is commonly manufactured in weight strengths of 20 to 60 percent. It is generally lower in detonation velocity, less dense, better in fume qualities, and considerably less sensitive to shock and friction than straight dynamite. Extra dynamite can be used effectively where the rock is not extremely hard and water conditions are not severe. It is widely used in quarrying, stripping, and in well-ventilated mines for smaller diameter holes of small blasting operations.
Low-density ammonia dynamite has a weight strength of approximately 65 percent and a cartridge strength from 20 to 50 percent. Like a high-density extra dynamite, it contains a low proportion of nitro-glycerin and a high proportion of ammonium nitrate. The different cartridge strengths are obtained by varying the density and grain size of the ingredients. Several manufacturers produce two series of low-density ammonia dynamite, a high- and a low-velocity series. Both series are of lower velocity and density than high-density extra dynamite. Because of its slow, heaving action, the low-velocity series is well suited to blasting soft material such as clay- shale or where a coarse product such as riprap is desired. It is well suited for use in structural excavation blasting in certain rock types.
Fume qualities and water resistance vary with the cartridge material. Wrappers sprayed with paraffin give fair to poor water resistance and fair fume rating, whereas a paraffin-impregnated wrapper gives very poor water resistance and a better fume rating. The explosive has little more water resistance than that provided by the wrapper. Low-density extra is the lowest cost cartridge explosive available. The composition of low-density ammonia dynamites is similar to that of a 60 percent high-density extra dynamite with a lower proportion of nitroglycerin and a higher proportion of ammonium nitrate.
Gelatin
Blasting gelatin is a rubber-textured explosive made by adding nitrocellulose (guncotton) to nitroglycerin. An antacid is added for stability in storage. Wood meal is usually added to improve sensitivity. Blasting gelatin attains a very high detonation velocity and has excellent water resistance, but it emits large volumes of noxious fumes upon detonation. It is the most powerful of all commercial explosives. Blasting gelatin is also known as "oil well explosive."
Nobel did much more than merely invent dynamite; he also invented blasting gelatine, gelatine dynamite, and gelignite, both of the latter being better suited for rock blasting than pure dynamite. Blasting gelatine was used to pierce the great St. Gothard Railway tunnel through rock so hard that without it the task could never have been accomplished. Blasting gelatine was tried in guns, but burst them, so Nobel set himself to discover an explosive less violent, yet equally clear and smokeless. By mixing nitroglycerine and guncotton he found a comparatively slow-burning powder which he called ballistite, and this, when he gave it to the world in 1888, caused a very great sensation.
Straight gelatin is a dense, plastic explosive consisting of nitroglycerin or other explosive oil gelatinized with. nitrocellulose, an antacid, sodium nitrate, carbonaceous fuel, and sometimes sulfur. Since the gelatin tends to coat the other ingredients, straight gelatin is water-proof. Straight gelatin is the equivalent of straight dynamite in the dynamite category and is manufactured in weight strengths of 20 to 90 percent with corresponding cartridge strengths of 30 to 80 percent. The cartridge strength or the weight strength may be referred to by the manufacturer as the "grade" of the gelatin, a term which is confusing. Straight gelatin has been used in very hard rock or as a bottom charge in a column of explosives. It has been replaced in most applications by a more economical substitute such as ammonia gelatin, brit higher grades are still used in underwater blasting and in deep well shooting.
Straight gelatin has two characteristic detonation velocities, the confined velocity and a much lower velocity which results from insufficient confinement, insufficient initiation, or high hydrostatic, pressure. Extremely high water pressures may cause a misfire. To overcome this disadvantage, high-velocity gelatin has been developed. High-velocity gelatin is very similar to straight gelatin except that it is slightly less dense, more sensitive to detonation, and always detonates near its rated velocity regardless of water pressure or degree of confinement. High-velocity gelatin is particularly useful as a seismic explosive, and is also used in deep well and underwater work.
Ammonia gelatin (special gelatin or gelatin extra) has a portion of the nitroglycerin and sodium nitrate replaced by ammonium nitrate. Ammonia gelatin is comparable to a straight gelatin in the same way that a high-density ammonia dynamite is comparable to a straight dynamite, and was developed as a cheaper substitute. Ammonia gelatin is commonly manufactured in weight strengths of 30 to 80 percent with corresponding cartridge strengths of 35 to 72 percent. Compared with straight gelatin, ammonia gelatin has a somewhat lower detonation velocity, better fume qualities, and less water resistance, although it will fire efficiently even after standing in water for several days. It is suitable for underground work because of its good fume rating. The higher strengths (70 percent or higher) are efficient as primers for blasting agents.
A semigelatin is comparable to an ammonia gelatin as a low-density ammonia dynamite is comparable to a high-density ammonia dynamite. Like low-density extras, semigelatin has a uniform weight strength (60 to 65 percent) with the cartridge strength varying with the density and grain size of the ingredients. Its properties fall betieen those of high- density ammonia dynamite and ammonia gelatin, and it has great versatility. Semigelatin can be used to replace ammonia dynamite when more water resistance is needed. It is cheaper for wet work than ammonia gelatin, although its water resistance is not quite as high as that of ammonia gelatin. Semigelatin has a confined detonation velocity of 10,000 to 12,000 fps, which, b contrast to that of most explosives, is not seriously affected by lack of confinement. Very good fume qualities permit its use underground. The compositions are similar to ammonia gelatin with less nitroglycerin and sodium nitrate and more ammonium nitrate.
H6
H-6 is a binary explosive that is a mixture of RDX, TNT, powered aluminum, and D-2 wax with calcium chloride added. H-6 is an Australian produced explosive composition used by the military for general purpose bombs.
HBX [Hexahydro - 1, 3, 5 Trinitro-8-Triazine]
HBX is a form of high explosive made from TNT, RDX, aluminum, lecithin, and wax. HBX was developed during WWII that replaced the more shock-sensitive TORPEX used in depth bombs and torpedoes. The warhead for the 2.75-inch "Mighty Mouse" rocket was filled with HBX (40 percent RDX, 38 percent TNT, 17 percent aluminum powder, and 5 percent desensitizers) or composition B (59 percent RDX, 40 percent TNT, and 1 percent wax). All Navy warhead filling activities in the TNT Plant ceased in early The major longer range improvements resulting were the Navy's development of HBX type explosives together with asphaltic, "hot melt" liners for bombs and other munitions. The hot melt liners were developed to coat and eliminate metal-to metal pinch points. After the Naval Magazine, Port Chicago, CA accident of 17 July 1944 , HBX and H-6 explosives were developed that incorporated wax and other chemicals to desensitize the explosive and hot melt liners were introduced for lining bombs and warheads to give some thermal protection and eliminate potential pinch points from cracks or fissures in the bomb or warhead case. Later, plastic-bonded explosives were developed for increased thermal protection and fragment impact resistance.
LX-14
Minol
Although ANFO is not generally suitable for military use, since it's troublesome to store without drying out, mixtures of AN and TNT known as "amatols" were used in both WWI and WWII as a means of stretching the supply of explosives. The proportion of AN in the mix ranged from 50% to 80%. A mix of ANFO, TNT, and powdered aluminum enhancer named "Minol" is still in use [40% TNT, 40% ammonium nitrate, 20% aluminum]. Owing to shortages of TNT and RDX (cyclonite) most World War II mines had had 50/50 ammonium nitrate and TNT (amatol) warheads. This was a low quality explosive but was later improved by the addition of about 20% aluminum to produce minol.
Octol
The melt-cast explosive Octol is a TNT-based explosive (70% HMX:30% TNT or 75 percent HMX, 25 percent TNT). Explosives to be stored on Navy ships must not contain TNT or Octol.
PBX
The ideal high-energy explosive must balance different requirements. HE should be easy to form into parts but resistant to subsequent deformation through temperature, pressure, or mechanical stress. It should be easy to detonate on demand but difficult to explode accidentally. The explosive should also be compatible with all the materials it contacts, and it should retain all its desirable qualities indefinitely.
No such explosive existed in 1944. While using what was available to meet wartime demands, scientists at Los Alamos began to develop a high-energy, relatively safe, dimensionally stable, and compositionally uniform explosive. By 1947, scientists at Los Alamos had created the first plastic-bonded explosive (PBX), an RDX*-polystyrene formulation later designated PBX 9205. Although other PBXs have since been successfully formulated for a wide range of applications, only a handful have displayed the combination of adequate energy content, mechanical properties, sensitivity, and chemical stability required for stockpile nuclear weapons. Since the 1960s, Livermore has been researching and developing safer HE for Livermore-designed weapons.
The plastic coating that binds the explosive granules, typically 5 to 20% of each formulation by weight, is what gives each PBX its distinctive characteristics. Pressing a PBX molding powder converts it into a solid mass, with the polymer binder providing both mechanical rigidity and reduced sensitivity to accidental detonation. The choice of binder affects hardness, safety, and stability. Too brittle a PBX can sustain damage in normal handling and succumb to extreme temperature swings or thermal shocks, while too soft a PBX may be susceptible to creep and may lack dimensional stability or strength.
PBXN-5
PBXN-5 is referred to as a plastic-bonded explosive because it is an explosive coated with plastic material. The composition is made of 95% HMX and 5% fluoroelastomers.
The Anti-Personnel Obstacle Breaching System (APOBS) Detonating Cord Assembly consists of PBXN-8 explosive, silicone rubber, polyamide yarn type I and II, and composition A-5 explosive. Grenade Assembly consists of PBXN-5 explosive booster pellet, PBXN-9 explosive pellets, grenade tube, and male and female grenade shells. Grenade Assembly consists of PBXN-5 explosive booster pellet, PBXN-9 explosive pellets, grenade tube, unisex grenade shells, and ring clamp.
PBXN-7
China Lake designed, developed, and qualified the Tomahawk Block III WDU-36 warhead in 48 months to meet evolving Tomahawk requirements of insensitive munitions ordnance compliance and range enhancement, while maintaining or enhancing ordnance effectiveness. The WDU-36 uses a new warhead material based upon prior China Lake warhead technology investigations, PBXN-107 explosive, the FMU-148 fuze (developed and qualified for this application), and the BBU-47 fuze booster (developed and qualified using the new PBXN-7 explosive). Block III was first used in the September 1995 Bosnia strike (Deliberate Force) and a year later in the Iraq strike (Desert Strike).
PBXN-9
PBXN-9 Explosive is made for the HELLFIRE/Longbow Missile System. Because of its acceptance into a number of fleet uses, additional characterization and performance tests were conducted on PBXN-9 to support various warhead developmental efforts. Included are the results of various explosive performance tests, such as detonation pressure, cylinder expansion (cylex),and wedge tests, as well as additional material sensitivity studies (large-scale gap test and small-scale gap test).
The JASSM contains the WDU-42/B (J-1000), a 1000-pound class, penetrating warhead with 240 pounds of AFX-757. AFX-757 is an extremely insensitive explosive developed by the Air Force Research Laboratory/High Explosives Research and Development Facility, Eglin AFB, Fla. The fuze is the FMU-156/B employing a 150-gram PBXN-9 booster.
The Anti-Personnel Obstacle Breaching System (APOBS) Detonating Cord Assembly consists of PBXN-8 explosive, silicone rubber, polyamide yarn type I and II, and composition A-5 explosive. Grenade Assembly consists of PBXN-5 explosive booster pellet, PBXN-9 explosive pellets, grenade tube, and male and female grenade shells. Grenade Assembly consists of PBXN-5 explosive booster pellet, PBXN-9 explosive pellets, grenade tube, unisex grenade shells, and ring clamp.
A Low-Energy Exploding Foil Initiator (LEEFI) is a low-energy input device with high-energy output that can detonate a main charge of PBXN-9.
PBXN-10
PBXN-106
This explosive is one of the new plastic-bonded explosives. It is a cast-cured explosive composition made from a homogeneous mixture of RDX in a plasticized polyurethane rubber matrix. Once cured, the material cannot be easily restored to a liquid state. The finished material is flexible and will absorb considerably more mechanical shock than conventional cast or pressed explosives.
PBXN-107
PBXN-109
PE4
PE4 is a conventional plastic explosive, widely used for the production of improved energetic systems for defensive and offensive use. PE4 is RDX based and is available in cartridge and bulk form. An extrudable for DEMEX 400 is also available. Distinctive standard colours indicate the explosive component: C4, or PE4 ( British) is white and Semtex-H is orange.
Pentolite
Pentolite is a mixture of equal parts of TNT and PETN. When cast, it has a specific gratity of 1.65 and a confined detonation velocity of 24,000 to 25,000 fps. Cast pentolite is used as a primer and booster for blasting agents where its high detonation pressure assures efficient initiation of the blasting agent.
Semtex
Semtex is an explosive containing both RDX and PETN. Semtex, a Czech-made explosive, has been used in many terrorist bombings. Dynamite has been replaced by the more destructive and easily concealed Semtex. SEMTEX is a plastic explosive that is odorless. SEMTEX along with a detonating cap, can be inserted inside a 5" x 6" musical greeting card, undetected. Three pounds of Semtex plastique packs enough punch to raze a two-story building. Terrorists attack with no warning and no rationale. Their weapon of choice is a pliable, odorless substance that is twice as powerful as TNT and is virtually invisible to conventional security devices. It can be hidden in a brief case or a small cassette recorder.
Czechoslovakia was among the world's chief arms exporters. It sold hundreds of tanks, thousands of firearms and large quantities of Semtex to Iran, Iraq, Libya, Syria, Cambodia and other trouble spots, a practice that stopped long ago. In 1985 and 1986, the Irish Republican Army [IRA] took delivery of nearly 120 tons of arms and explosives from Libya, including a ton of Semtex explosive and 12 SAM-7 surface-to-air missiles. Some of those weapons and explosives have been used by the IRA in terrorist attacks in the United Kingdom and in other European countries. Libyan terrorists used Semtex in 1988 to down Pan Am Flight 103 over Lockerbie, Scotland, killing 270 persons.
The on-again, off-again export of the general-purpose plastic explosive Semtex, manufactured in Czechoslovakia during the height of the Cold War and linked to terrorist groups around the world, resumed in 1994. The Czech Republic recently announced that exports were beginning to selected countries. The first Semtex shipment under the resumed exportswent to the British Defense Ministry. Czech reporting suggested that the British authorities intend to run experiments on the explosive that is often used by Irish Republican Army terrorists-including the October 1993 destruction of a building in Belfast.
According to the 1991 international convention signed in Montreal, Semtex intended for industrial applications is to be a bright red-orange color and detectable by security-monitoring equipment. Variants of the explosive produced for civilian purposes are also less powerful than the nearly odorless version that became a favorite weapon of terrorists. Despite this and the export ban that had earlier been in place, Semtex continues to be smuggled across borders.
Substantial quantities of the explosive have been stolen from industrial enterprises in the Czech and Slovak republics for sale on the black market. Shortly before the most recent ban was lifted, Czech police seized 100 kilograms of industrial Semtex from a group of Czech citizens who were planning its illegal sale abroad. In Slovakia in October 1993, some 900 kilograms of the explosive were stolen from the warehouse of a private firm, together with more than 2,000 detonators. Czech officials candidly admit that they have no idea how much Semtex has been stolen or illegally diverted, and the continued black market trade in the explosive seems certain.
Slurries
Slurries, sometimes called water gels, contain ammonium nitrate partly in aqueous solution. Depending on the remainder of the ingredients, slurries can be classified as either blasting agents or explosives. Slurry blasting agents contain nonexplosive sensitizers or fuels such as carbon, sulfur, or aluminum, and are not cap sensitive; whereas slurry explosives contain cap- sensitive ingredients such as TNT and the mixture itself may be cap sensitive. Slurries are thickened and gelled with a gum, such as guar gum, to give considerable water resistance.
Since most slurries are not cap sensitive, all slurries, even those containing TNT, are often grouped under the term blasting agent. This grouping is incorrect. A blasting agent, as defined by the National Fire Protection Association, shall contain no ingredient that is classified as an explosive.
Slurry blasting agents require adequate priming with a high-velocity explosive to attain proper detonation velocities, and often require boosters of high explosive spaced along the borehole to as sure complete detonation. Slurry explosives may or may not require priming. The detonation velocities of slurries, between i2,000 and 18,000 fps, vary with ingredients used, charge diameter, degree of confinement, and density. The detonation velocity of a slurry, however, is not as dependent on charge diameter as that of a dry blasting agent. The specific gratity varies from I.i to i.6. The consistency of most slurries ranges from fluid near iOOO F to rigid at freezing temperatures, although some slurries maintain their fluidity even at freezing temperatures. Slurries consequently give the same advantageous direct borehole coupling as dry blasting agents as well as a higher detonation velocity and a higher density. Thus, more energy can be loaded into a given volume of borehole. Saving in costs realized by drilling smaller holes or using larger burden and spacing will often more than offset the higher cost per pound of explosive. Adding powdered aluminum as a sensitizer to slurries greatly increases the heat of explosion or the energy release. Aluminized slurries have been used in extremely hard rock with excellent results.
A slurry and a dry blasting agent may be used in the same borehole in "slurry boosting," with the buk of the charge being dry blasting agent. Boosters placed at regular intervals may improve fragmentation. In another application of slurry boosting, the slurry is placed in a position where fragmentation is difficult, such as a hard toe or a zone of hard rock in the burden. The combination will often give better overall economy than straight slurry or dry blasting agent.
Tetrytol
Tetrytol is a mixture of ~70% tetryl (2,4,6-trinitrophenyl-methylnitramine) and ~30% TNT (2,4,6-trinitrotoluene. In 1944 the M104 auxiliary booster was first given to Redstone Arsenal as an experimental order with instructions to develop a manufacturing procedure for loading it with tetrytol. The booster had heretofore been loaded with tetryl pellets. The tests that Redstone conducted showed that tetrytol-loaded M104 auxiliary boosters had a greater brisance than the tetryl-loaded ones but that a heavier booster charge was required for detonation. Since such a booster charge was already available, the tetrytol-loaded auxiliary booster was considered more satisfactory than the tetryl-loaded one.
TORPEX
TORPEX is an explosive based on trinitrotoluene (TNT) that gave a greater blast than TNT, but was more sensitive. It was replaced by HBX or HBX-1 later in WWII. Torpex is RDX/TNT/Aluminum/Wax desensitizer. It was used in several types of torpedoes and mines. Due to it sensitivity to bullet impact, the first weapons loaded were ones for which there would be the least possibility of rifle bullet and fragment attack, namely, submarine delivered mines and torpedoes. The loading stations were advised that they must take adequate care in mixing and loading and in the handling of the loaded items. It was declared that the British had been able to handle it without incident for 2 years and that the risk was worth the advantage gained in its underwater power.
Tritonal
The GBU-28 contains only six hundred pounds of Tritonal. The BLU-109/B was an improved 2,000-pound-class penetrator bomb designed for attacking the most hardened targets. Its skin was much harder than that of a standard iron bomb, consisting of a single-piece, forged warhead casing of one-inch, high-grade steel. The bomb featured a 550 pound tritonal high-explosive blast warhead and was always mated with a laser guidance kit to form a laser-guided bomb. The Tritonal filling of the BLU-109/B is similar in size to the warhead of the Mk.48 series torpedo. Explosive (NEW) 535 lbs. Tritonal in the BLU-109 and 945 lbs. of Tritonal on the MK 84.
The Munitions Directorate's successful completion of the Miniaturized Munition Technology Demonstration (MMTD) Program, has provided an innovative weapon called the Small Smart Bomb. The miniaturized munition concept includes a weapon that issix feet long, six inches in diameter, and weighs only 250 pounds with approximately fifty pounds of Tritonal explosive material. The weapon is effective against a majority of hardened targets previously vulnerable only to munitions in the 2,000 pound class. The Air Force Research Laboratory's Munitions Directorate has set the baseline for small bomb development by successfully demonstrating the technology that will be used to further the development of a 250-pound class munition. Small Smart Bomb's size will allow future fighter and bomber aircraft to carry more weapons in their weapons bays.
Polynitrocubane Super Explosives are a family of new energetics. In FY96, the Army initiated the synthesis of a more powerful polynitrocubane explosive. In FY97, the Army scaled up the polynitrocubane explosive to pound level. In FY98, scale up the polynitrocubane explosive to pilot plant quantity and initiate formulation study for anti-armor warhead (Shaped Charge or explosively Formed Penetrator) loading. In FY99, conduct static warhead test using the polynitrocubane explosive to show increase in energy performance by up to 25 percent and with comparable sensitivity to LX-14.
The current winner in the most powerful explosives debate is heptanitrocubane (HpNC). It has beat out the theoretically more powerful octanitrocubane (ONC) in actual tests recently performed. ONC has only been synthesized in the last year, but it has been calculated to have the greatest density of any explosive we could make. In reality ONC does not achieve this theoretical density. Since it has existed for such a short time, researchers conclude that they simply have yet to find its most dense crystalline form. The default winner is the next best thing, HpNC. Further conjecture into nitro cubane chemistry has hypothesized at the possibility of polynitrocubane molecules which could achieve even greater densities.
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