Dynamite
Dynamite is an explosive based on the explosive potential of
nitroglycerin, initially using
diatomaceous
earth (kieselguhr) as an adsorbent. It was invented by Swedish chemist and engineer Alfred Nobel in 1866 in Krümmel (Hamburg, Germany) and patented in 1867. It is usually sold in the form of a stick 20 cm (roughly eight inches) long and 2.5 cm (one 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 in
nitroglycerin dissolved in nitrocellulose and a little ketone to in the mixing process. Its formula is, thus, similar to cordite. This form of dynamite is much safer than the simple mix of nitroglycerin and kieselguhr.
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Etymology
The word dynamite comes from the Greek word δυναμις (dynamis), meaning power, and the Greek suffix -ιτης (-itēs), meaning small.
Uses and composition
The chief uses of dynamite used to be in construction, mining and demolition. However, newer explosives and techniques have replaced dynamite in many applications. Dynamite is still used, mainly as bottom charge or in underwater blasting. Dynamite has been used in armed conflicts, mainly to destroy bridges and other ways of travel, to slow the advance of supplies or enemy troops. Enthusiasts interested in safe-cracking have deliberately extracted nitroglycerin from dynamite by boiling the sticks and ''skimming'' the nitroglycerin as it is forced out.
Dynamite consists of three 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 (i.e., 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 into diatomaceous earth, nitroglycerin is less shock-sensitive.
Over time, the dynamite will "weep" or "sweat" its nitroglycerine, which can then pool in the bottom of the box or storage area. Crystals will form on the outside of the sticks. This creates a very dangerous situation. While the actual possibility of explosion without a cap is minimal, old dynamite is still dangerous.
A priming device is used for initiating dynamite. The device should include a shell, preferably formed of a material in a compartment at one end for housing a sensitive explosive material which is more sensitive than the dynamite to be detonated. Also included in primer units are passageways which are open at both ends of the shell for receiving and housing an electric blasting cap.
Dynamite is also frequently used in ski resorts. The safety patrolers use sticks of dynamite to purposfully create avalanches so the runs can be safe once the people arrive.