C-4 or Composition 4 is a common variety of military plastic explosive.
The term composition is used for any stable explosive, and "Composition A" and "Composition B" are other known variants. C-4 is 1.34 times as explosive as trinitrotoluene (TNT).
The term composition is used for any stable explosive, and "Composition A" and "Composition B" are other known variants. C-4 is 1.34 times as explosive as trinitrotoluene (TNT).
Composition
C-4 is made up of explosives, plastic binder, plasticizer and, usually, marker or taggant chemicals such as 2,3-dimethyl-2,3-dinitrobutane (DMDNB) to help detect the explosive and identify its source.
As with many plastic explosives, the explosive in C-4 is RDX (cyclonite or cyclotrimethylene trinitramine), which makes up around 91% of C-4 by weight. The plasticizer is diethylhexyl or dioctyl sebacate (5.3%) and the binder is usually polyisobutylene (2.1%).
Another plasticizer used is dioctyl adipate (DOA). A small amount of SAE 10 non-detergent motor oil (1.6%) is also added. C-4 detonates with a pressure wave of about 8,040 m/s (26,400 ft/s), or 28,900 km/h (18,000 mph).
C-4 is manufactured by combining the noted ingredients with binder dissolved in a solvent. The solvent is then evaporated and the mixture dried and filtered. The final material is an off-white solid with a feel similar to modelling clay. 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 (51 mm) by 1.5 inches (38 mm) and 11 inches (280 mm) long, weighing 1.25 lb (0.57 kg). 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. 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", 4.6 kg (10 lb) of explosive will usually be sufficient. Another formula is to use 2 pounds (1 kg) of explosive for every 30 cm (1 ft) of penetration in frozen water.
Advantages
A major advantage of C-4 is that it can easily be molded into any desired shape. C-4 can be pressed into gaps, cracks and voids in buildings, bridges, equipment or machinery. Similarly, it can easily be inserted into empty shaped-charge cases of the type used by military engineers.
C-4 is very stable and insensitive to most physical shocks. Detonation can only be initiated by a combination of extreme heat and a shockwave, as when a detonator inserted into it is fired. C4 cannot be detonated by a gunshot or by dropping it onto a hard surface.
C-4 is made up of explosives, plastic binder, plasticizer and, usually, marker or taggant chemicals such as 2,3-dimethyl-2,3-dinitrobutane (DMDNB) to help detect the explosive and identify its source.
As with many plastic explosives, the explosive in C-4 is RDX (cyclonite or cyclotrimethylene trinitramine), which makes up around 91% of C-4 by weight. The plasticizer is diethylhexyl or dioctyl sebacate (5.3%) and the binder is usually polyisobutylene (2.1%).
Another plasticizer used is dioctyl adipate (DOA). A small amount of SAE 10 non-detergent motor oil (1.6%) is also added. C-4 detonates with a pressure wave of about 8,040 m/s (26,400 ft/s), or 28,900 km/h (18,000 mph).
C-4 is manufactured by combining the noted ingredients with binder dissolved in a solvent. The solvent is then evaporated and the mixture dried and filtered. The final material is an off-white solid with a feel similar to modelling clay. 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 (51 mm) by 1.5 inches (38 mm) and 11 inches (280 mm) long, weighing 1.25 lb (0.57 kg). 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. 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", 4.6 kg (10 lb) of explosive will usually be sufficient. Another formula is to use 2 pounds (1 kg) of explosive for every 30 cm (1 ft) of penetration in frozen water.
Advantages
A major advantage of C-4 is that it can easily be molded into any desired shape. C-4 can be pressed into gaps, cracks and voids in buildings, bridges, equipment or machinery. Similarly, it can easily be inserted into empty shaped-charge cases of the type used by military engineers.
C-4 is very stable and insensitive to most physical shocks. Detonation can only be initiated by a combination of extreme heat and a shockwave, as when a detonator inserted into it is fired. C4 cannot be detonated by a gunshot or by dropping it onto a hard surface.
Posts
No comments:
Post a Comment