cordite n : explosive powder (nitroglycerin and guncotton and petrolatum) dissolved in acetone and dried and extruded in brown cords

English

Etymology

From cord (the material is manufactured into short cordlike, 1mm diameter cylinders) + -ite.

Noun

1. A smokeless propellent made by combining two high explosives: nitrocellulose and nitroglycerine used in some firearm ammunition.

Cordite is a family of smokeless propellants developed and produced in the United Kingdom from 1889 to replace gunpowder as a military propellant. Cordite was used for large weapons, such as tank guns, artillery and naval guns. It was also used in the .303 British, Mark I and II, standard rifle cartridge between 1891 and 1915; however shortages of cordite in World War I led to US-developed smokeless powders being imported into the UK for use in rifle cartridges. Cordite has been used since World War I by the UK and British Commonwealth countries. Its use was further developed in the early years of World War II, as 2 inch and 3-inch diameter Unrotated Projectiles for launching anti-aircraft weapons. Small Cordite rocket charges were also developed for ejector seats made by the Martin-Baker Company. Cordite is now obsolete and it is no longer produced. Production ceased in the United Kingdom, around the end of the 20th century, with the closure of the last World War II Cordite factory, ROF Bishopton. However, Cordite propellant may still be encountered in the form of legacy ammunition dating from World War II onwards.

Adoption of smokeless powder by the British government

Cordite started off as a double-base propellant. It was made by combining two high explosives: nitrocellulose and nitroglycerine.

Early European smokeless powders

The first smokeless powder, Poudre B, was developed in 1884 by the French chemist Paul Vieille. It was made out of two forms of nitrocellulose (collodion and guncotton) softened with ethanol and ether and kneaded together. It was immediately adopted by the French military but it tended to become unstable over time. The rifle and cartridge developed to utilize this powder were known generically as the '8mm Lebel', after the officer in charge of the development board, and were fielded in 1886.

The following year, 1887, Alfred Nobel invented and patented a smokeless propellant he called Ballistite. It was composed of 10% camphor, 45% nitroglycerine and 45% collodion (nitrocellulose). Over time the camphor tended to evaporate leaving an unstable explosive.

Development of cordite

A United Kingdom government committee, known as the "Explosives Committee", chaired by Sir Frederick Abel, monitored foreign developments in explosives and obtained samples of Poudre B and Ballistite. However, neither of these smokeless powders were recommended for adoption by the Explosives Committee.

Abel and Sir James Dewar, who was also on the committee, developed and jointly patented in 1889 a new propellant consisting of 58% nitroglycerine, by weight, 37% guncotton and 5% vaseline.

Using acetone as a solvent, it was extruded as spaghetti-like rods initially called "cord powder" or "the Committee's modification of Ballistite" but this was swiftly abbreviated to "Cordite".

Nobel and Abel patent dispute

Nobel sued Abel and Dewar over an alleged patent infringement. His patent specified that the nitrocellulose should be "of the well-known soluble kind". This dispute eventually reached the House of Lords, in 1895, but lost because the words "of the well-known soluble kind" in his patent were taken to mean the soluble collodion and hence specifically excluded the insoluble guncotton.

Cordite formulations

It was quickly discovered that the rate of burning could be varied by altering the surface area of the cordite. Narrow rods were used in small-arms and gave relatively fast burning, while thicker rods would burn more slowly and were used for longer barrels such as those used in artillery and naval guns.

Cordite (Mk I) and Cordite MD

The original Abel-Dewar formulation was soon superseded as it caused excessive gun barrel erosion. It has since become known as Cordite Mk I.

The composition of Cordite was changed to 65% guncotton and 30% nitroglycerine (keeping 5% vaseline) shortly after the end of the Second Boer War. This was known as Cordite MD (= MoDified). Cordite MD is also obsolete.

Cordite RDB

During the World War I acetone was in short supply in Great Britain and a new experimental form was developed. This was Cordite RDB (= Research Department formula B); which was 52% collodion, 42% nitroglycerine and 6% vaseline (Petroleum jelly). It was produced at HM Factory, Gretna; The ICI Ardeer site also had a mothballed World War I Government-owned Cordite factory.

35% of British Cordite produced between 1942 and 1945 came from Ardeer and these agency factories. ICI ran a similar works at Deer Park near Melbourne in Australia and in South Africa.

The Imperial Munitions Board set up a number of additional explosives factories in Canada. It built The British Cordite Ltd factory at Nobel, Ontario, in 1916/1917, to produce Cordite. Production started in mid 1917. The Canadian Explosives Limited Cordite factory at Nobel, Ontario was designed to produce 1,500,000 lb (681 tonne) of Cordite per month (approximately 8,170 tonnes per year).

Between wars

HM Factory, Gretna, and the Royal Navy Cordite Factory, Holton Heath, both closed after the end of the war and the Gretna factory was dismantled. This left Waltham Abbey and Ardeer in production.

References

Notes

Bibliography

• Bowditch, M.R. and Hayward, L. (1996). A Pictorial record of the Royal Naval Cordite Factory: Holton Heath. Wareham: Finial Publishing. ISBN 1-900467-01-1.
• Brown, Donald, (1999), Somerset v Hitler: Secret Operations in the Mendips 1939 - 1945, Newbury: Countryside Books. ISBN 1-85306-590-0.
• Carnegie, David (1925). The History of Munitions Supply in Canada 1914-1918. London: Longmans, Green and Co.
• Cocroft, Wayne D. (2000). Dangerous Energy: The archaeology of gunpowder and military explosives manufacture. Swindon: English Heritage. ISBN 1-85074-718-0.
• Davis, Tenney L. (1943). The Chemistry of Powder and Explosives, Volume II, New York: John Wiley & Sons, and London: Chapman & Hall.
• Hartcup, Guy (1970). The Challenge of War: Scientific and Engineering Contributions to World War Two. Newton Abbot: David & Charles. ISBN 0-7153-4789-6.
• Reader, W.J. (1975). Imperial Chemical Industries: A History. Volume II; The First Quarter-Century 1926-1952. London: Oxford University Press. ISBN 0-19-215944-5.
• Ministry of Munitions of War, (1919). H.M. Factory, Gretna: Description of plant and process. Dumfries: J. Maxwell and Son, for His Majesty's Stationery Office.