Image:Dynamite-5.svg|thumb|Diagram of dynamite.
A. Sawdust (or any other type of absorbent material) soaked in nitroglycerin.
B. Protective coating surrounding the explosive material.
C. Blasting cap.
D. Electrical cable connected to the blasting cap.
Dynamite
is an explosive material based (in its standard form) on the explosive potential of nitroglycerin, initially using diatomaceous earth (kieselgur: United States spelling; kieselguhr: UK spelling) or another absorbent substance such as sawdust as an absorbent. It was invented by Swedish chemist and engineer Alfred Nobel in 1866 in Krümmel (Geesthacht, Schleswig-Holstein, Germany), and patented in 1867. Military dynamite
achieves greater stability by avoiding nitroglycerin. [1]
It is usually sold in the form of a stick 20 centimetres (roughly 8 inches) long and 2.5 centimetres (1 inch) in diameter, but other sizes also exist. Dynamite is considered a high explosive, which means it detonates rather than deflagrates.
Another form of dynamite consists of nitroglycerin dissolved in nitrocellulose and a small amount of ketone. This form of dynamite is similar to cordite. This form of dynamite is much safer than the simple mix of nitroglycerin and diatomaceous earth/kieselgur.
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DYNAMITE! TICKETS
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Uses
Dynamite is predominantly used in the
mining, quarrying, and construction industries and has had historical use in warfare, but the unstable nature of nitroglycerin, especially if subjected to freezing, has rendered it obsolete for modern military use.
Military
Briefly in the late 19th century,
dynamite guns were used experimentally and in very limited combat. The early US Navy submarine
USS Holland included a dynamite gun in its armament. Limited range and sensitivity of nitroglycerin based dynamite led to the early abandonment of dynamite guns.
Dynamite has been replaced for combat engineering purposes (construction) by 'military dynamite', a stable mixture of
TNT,
RDX, inert binders and anti-freeze agents. Military dynamite is equivalent in strength to 60 percent straight nitroglycerin commercial dynamite and is used by the military as a direct replacement for "60% straight dynamite".
[2]
History
Dynamite was invented by
Alfred Nobel and was the first safely manageable explosive stronger than
black powder. Nobel obtained
patents for his invention: in England on 7 May 1867 and in
Sweden on 19 October 1867.
[3] He originally sold dynamite as
"Nobel's Blasting Powder"
. After its introduction, dynamite rapidly gained popularity as a safe alternative to
gunpowder and
nitroglycerin. Nobel tightly controlled the patent, and unlicensed duplicators were quickly shut down. However, a few
American businessmen got around the patent by using a slightly different formula.
Manufacture
Classic dynamite consists of 3 parts
nitroglycerin, one part diatomaceous earth and a small admixture of
sodium carbonate. This mixture is formed into short sticks and wrapped in paper. Nitroglycerin by itself is a very strong explosive, and in its pure form it is shock-sensitive (physical shock can cause it to explode), degrading over time to even more unstable forms. This makes it highly dangerous to transport or use in its pure form. Absorbed onto diatomaceous earth or more commonly sawdust, nitroglycerin is less shock-sensitive.
Over time, the dynamite will "weep" or "sweat" its nitroglycerin, which can then pool in the bottom of the box or storage area. (For that reason, explosive manuals recommend turning boxes of dynamite in storage.) Crystals will form on the outside of the sticks. This creates a very dangerous situation. While the actual possibility of explosion without a
blasting cap is minimal, old dynamite is still dangerous.
South Africa
For several decades from the 1940s, the biggest producer of dynamite in the world was the
Republic of South Africa, where
De Beers established a factory in 1902 at
Somerset West. The explosives factory was later operated by
AECI (African Explosives and Chemical Industries). The demand for the product came mainly from the country's vast gold mines, centered on the
Witwatersrand. The factory at Somerset West was in operation in 1903 and by 1907 was already producing 340,000 cases (22 kilograms (50 lb) each) annually. In addition, a rival factory at Modderfontein was producing another 200,000 cases per year.
[4]
One of the drawbacks of dynamite was that it was dangerous to manufacture. There were two large explosions at the Somerset West plant in the 1960s. Some workers died, but loss of life was limited by the modular design of the factory and earth works and plantations of trees that directed the blasts upwards. Pressure from trade unions forced AECI, after 1985, to phase out production of dynamite. The factory then went on to solely supply ammonium nitrate emulsion based explosives that are far safer to manufacture.
[5]
United States
In the United States, in 1885, chemist
Russell S. Penniman invented
ammonium dynamite, a form which used
ammonium nitrate in addition to the more costly nitroglycerin. These dynamites were marketed with the trade name "Extra". Ammonium nitrate has 85% of the energy of "straight" nitroglycerin. Dynamite was manufactured by the
E. I. du Pont de Nemours & Company, Inc. until the mid-1970s. Other U.S. dynamite makers of the era included
Hercules, Atlas, Trojan-US Powder, Austin, and several other smaller firms. Dynamite was eventually phased out in favor of
water gel explosives, which are cheaper to manufacture and in many ways safer to handle.
[6]
Difference from TNT
It is a common
misconception that
TNT and dynamite are the same thing.
[7] Though both are high explosives, there is no other similarity between them. While dynamite is an absorbent mixture soaked in nitroglycerin, then compacted into a cylindrical shape and wrapped in paper, TNT is a specific chemical compound called 2,4,6-trinitrotoluene.
A stick of dynamite contains roughly 2.1 million
joules of energy.
[8] The energy density (joules/
kilogram) of dynamite is approximately 7.5 megajoules/kilogram, compared to 4.6 megajoules/kilogram of TNT.
See also
- Nitroglycerin
- Nobel Prize
- Titadine
- TNT
- Tovex
Patent