The invention of Smokeless Powder

 

Gun cotton

German-Swiss chemist Christian Friedrich Schönbein (1799-1868) made his mark by discovering ozone. Schönbein researched in the autumn of 1845 a mixture of concentrated sulphuric acid and nitric acid on cotton. Cotton is nearly pure celluloid. Treatment with the above mentioned acids is called nitration. The process adds oxygen and nitrogen to the cellulose molecule. By the reaction of the celluloid with the nitric acid water come into being. The water is absorbed by the very hygroscopic sulphuric acid.

 

The, by the process of nitration, obtained nitrocellulose is extremely inflammable. When closed up in a small room it will explode or even detonate. The product looks very much like the untreated cotton. Schönbein called the nitrated celluloid schiessbaumwolle, which literally translated, means shooting cotton. It is better known as gun cotton. Gun cotton leaves no pollution when it is pure enough. Besides this it is much more powerful than black powder.

 

Christian Friedrich Schönbein 1799-1868.

Source: http://www.atmosphere.mpg.de.

 

Gun cotton also had some drawbacks. It was difficult to control its burning rate and no gun is capable to cope with detonation. The Practice learned that gun cotton decompose as time passes which caused spontaneous explosion ! Unfamiliarity with this quality led to the explosion of an English factory in Faversham in 1847. A French store in Vincennes followed in 1848. Later on, even the most pure gun cotton spontaneous explodes in 1862 and 1865 in Austria. This led to a ban of this extremely dangerous substance.

 

 

Single base smokeless powder

The French chemist Vieille tamed the gun cotton in 1884. Gun cotton can be solved in a blend from alcohol and ether or acetone. After drying a compound similar to gelatine is obtained.

 

The obtained product has a far more constant burning rate than gun cotton. Besides this, the compound can be pressed and cut in different shapes and dimensions. This is important because the grain geometry have a profound effect on the burning cycle. Only the surface can burn. A grain with a large surface will burn faster then a grain with the same weight but a smaller surface. For example the surface of a grain is larger when the grain is perforated. Also after burning some amount of the grain its surface will increase or decrease depending of its initial shape. This made the burning rate controllable.

 

Stabilizer, for example diphenylamine, is added to prevent the autocatalytic decomposition of the nitrocellulose that had led to the ban on gun cotton. This on nitrocellulose based, propellant is called single base smokeless powder. The invention of Vieille, with some improvements, is still in use with most modern smokeless powders for small arms today.

 

A French soldier with the French Lebel Mle.1886.

Source: http://www.military-photos.com.

 

The French Lebel Mle.1886 was the first rifle that was chambered for a cartridge loaded with the single base smokeless powder from Vieille. The Portuguese Lieutenant Luis Guedes Dias had a good relationship with the French military. He had gathered information from the French for his development of the 8x60R cartridge. During this time the French developed their 8x51R cartridge. Despite of their good relationship with Lieutenant Guedes the French apparently kept the secret of the invention of smokeless powder in 1884 for their own.

 

 

Double base smokeless powder

In 1847 the Italian chemist Ascanio Sobrero (1812-1888) discovered nitroglycerine.  The Swede Alfred Nobel produced this explosive. He also starts experimenting with nitroglycerine in 1860. Nitroglycerine is very unsafe to handle. Alfred lost his brother Emil and several employees during the production of nitroglycerine. The Swedish authorities forbade him further experimentation in Stockholm. An explosion also destroys Alfred Nobel & Co in Krümmel near Hamburg, Germany. Alfred Nobel & Co was later on formed to Dynamit Nobel Aktien Gesellschaft (DAG) in 1876. The concern of Dynamit Nobel AG still produces ammunition today.

 

Nitroglycerine is a yellow colored liquid. Alfred Nobel found that mixing nitroglycerine with "kieselguhr" (silica), would turn the liquid into a paste. Kieselguhr is a fine sand. The paste could be shaped into rods of a size and form suitable for insertion into drilling holes. In 1867 he patented this material under the name of dynamite. This name has its origins in the Greece word "dynamis" that means power. Dynamite is far more shockproof than nitroglycerine and only able to detonate by a blasting cap. The blasting cap, called detonator, is also in invention of Alfred Nobel. No gun can withstand the violence of a detonation. Dynamite is by no means suitable as a propellant for small arms.

 

Alfred Bernard Nobel 1833 - 1896

Source: http://nobelprize.org

 

Single base smokeless powder, invented by the French Vieille, colloid nitrocellulose by the use of solvents like alcohol and ether. Nobel found that the addition of nitro-clycerine to nitro-cellulose increases the energy of the powder. Nitrocelluose powder with a significant percentage of nitroglycerine is called double base smokeless powder. Nobel gave his invention of double base smokeless powder the name Ballistite. Double base smokeless powders are still in use for small arms but not as much as the single base powders.

 

In 1887 Alfred Nobel obtains a patent for Ballistite in France. In 1891 Nobel leaves Paris, France, and settles in San Remo, Italy, after a dispute with the French government about Ballistite. The first propellant of the 6.5 x 52 Carcano cartridges was Ballistite.

 

In 1896 the hot Ballistite is replaced by the Italians with the far less erosive Solenite. Solinite was also a double-base, nitro-cellulose powder but with a significantly lower percentage of nitro-glycerine. Great Britain would adopt a nearly identical propellant for their .303 cartridge in 1901, called Cordite. Ballistite would remain for special loads such as blanks.

 

Credits