Cordite

Cordite is a family of

Cordite was used initially in the .303 British, Mark I and II, standard rifle cartridge between 1891 and 1915.^{[not verified in body]} Shortages of cordite in World War I led to the creation of the "Devil's Porridge" munitions factory (HM Factory, Gretna) on the English-Scottish border, which produced around 800 tonnes of cordite per week. The UK also imported some United States–developed smokeless powders for use in rifle cartridges. Cordite was also used for large weapons, such as tank guns, artillery, and naval guns. It has been used mainly for this purpose since the late 19th century by the UK and British Commonwealth countries. Its use was further developed before World War II, and as 2-and-3-inch-diameter (51 and 76 mm) Unrotated Projectiles for launching anti-aircraft weapons.^[1] Small cordite rocket charges were also developed for ejector seats made by the Martin-Baker Company. Cordite was also used in the detonation system of the Little Boy atomic bomb dropped over Hiroshima in August 1945.^[2]

The term "cordite" generally disappeared from official publications between the wars. During World War II,

The following year, 1887, Alfred Nobel invented and patented a smokeless propellant he called Ballistite.^[11] It was composed of 10% camphor, 45% nitroglycerine and 45% collodion (nitrocellulose). Over time the camphor tended to evaporate, leaving an unstable explosive.^[12]

Development

A United Kingdom government committee, known as the "Explosives Committee", chaired by Sir

Cordite began as a double-base propellant. In the 1930s triple-base was developed by including a substantial proportion of nitroguanidine. Triple-base propellant reduced the disadvantages of double-base propellant – its relatively high temperature and significant flash. Imperial Chemical Industries's (ICI) World War 2 double-base AN formulation also had a much lower temperature, but it lacked the flash reduction properties of N and NQ triple-base propellants.^{[citation needed]}

Whilst cordite is classified as an explosive, it is not employed as a high explosive. It is designed to deflagrate, or burn, to produce high pressure gases.^{[citation needed]}

Nobel and Abel patent dispute

Alfred Nobel sued Abel and Dewar over an alleged

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 were 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.^[citation needed]

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.^{[citation needed]}

The composition of cordite was changed to 65% guncotton, 30% nitroglycerin (keeping 5% petroleum jelly), and 0.8% acetone shortly after the end of the Second Boer War. This was known as Cordite MD (modified).^[16]

Cordite MD cartridges typically weighed approximately 15% more than the cordite Mk I cartridges they replaced, to achieve the same muzzle velocity, due to the inherently less powerful nature of Cordite MD.^[17]

Cordite RDB

During World War I acetone was in short supply in Great Britain, and a new experimental form was developed for use by the

Acetone for the cordite industry during late World War I was eventually produced through the efforts of Dr. Chaim Weizmann, considered to be the father of industrial fermentation. While a lecturer at Manchester University Weizmann discovered how to use bacterial fermentation to produce large quantities of many desired substances. He used the bacterium Clostridium acetobutylicum (the so-called Weizmann organism) to produce acetone. Weizmann transferred the rights to the manufacture of acetone to the Commercial Solvents Corporation in exchange for royalties. After the Shell Crisis of 1915 during World War I, he was director of the British Admiralty Laboratories from 1916 until 1919.^{[citation needed]}

Cordite RDB was later found to become unstable if stored too long.^{[citation needed]}

Cordite SC

Research on solvent-free Cordite RDB technologically extremely similar to ballistite continued primarily on the addition of stabilizers, which led to the type commonly used in

Two-inch (approximately 50 mm) and three-inch (approximately 75 mm) diameter, rocket Cordite SC charges were developed in great secrecy before World War II for anti-aircraft purposes—the so-called Z batteries, using 'Unrotated Projectiles'.^[1]

Great Britain changed to metric units in the 1960s, so there was a discontinuity in the propellant geometry numbering system.^{[citation needed]}

Cordite N

An important development during World War II was the addition of another explosive, nitroguanidine, to the mixture to form triple-base propellant or Cordite N and NQ. The formulations were slightly different for artillery and naval use. This solved two problems associated with the large naval guns fitted to British Navy's capital ships: gun flash and muzzle erosion. Nitroguanidine produces large amounts of nitrogen when heated, which had the benefit of reducing the muzzle flash, and its lower burning temperature greatly reduced the erosion of the gun barrel.^{[citation needed]}

N and NQ were also issued in limited amounts to ammunitions used by the British

After World War II production of double-base propellants generally ended. Triple-base propellants, N and NQ, were the only ones used in new ammunition designs, such as the cartridges for 105 mm Field and for 155 mm FH70.^{[citation needed]}

Charge design

Manufacture

UK Government factories

In Great Britain cordite was developed for military use at the Royal Arsenal by Abel, Dewar and Kellner, Woolwich,^[19] and produced at the Waltham Abbey Royal Gunpowder Mills from 1889 onwards.^[20]

At the start of World War I cordite was in production at Waltham Abbey Royal Gunpowder Mills and by seven other suppliers (British Explosives Syndicate Ltd, Chilworth Gunpowder Company Ltd, Cotton Powder Company Ltd, Messrs Curtis's and Harvey Ltd, National Explosives Company Ltd, New Explosives Company Ltd and Nobels Explosive Company Ltd).^[21] . Existing factories were expanded and new ones built notably by Nobel's at Ardeer,

By the start of World War II Holton Heath had reopened, and an additional factory for the Royal Navy, The

35% of British cordite produced between 1942 and 1945 came from Ardeer and these agency factories.[24] ICI ran a similar works at Deer Park (which was also confusingly known as Ardeer after the adjacent suburb) near Melbourne in Australia and in South Africa.^[24]

Overseas supplies

Additional sources of propellant were also sought from the British Commonwealth in both World War I and World War II. Canada, South Africa, and Australia had ICI-owned factories that, in particular, supplied large quantities of cordite.^{[citation needed]}

World War I

Canadian Explosives Limited was formed in 1910 to produce rifle cordite, at its Beloeil factory, for the Quebec Arsenal. By November 1915 production had been expanded to produce 350,000 lb (159,000 kg) of cordite per month for the Imperial Munitions Board.^[25]

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.^[25]

Canadian Explosives Limited built an additional cordite factory at Nobel, Ontario. Work started in February 1918 and was finished on 24 August 1918. It was designed to produce 1,500,000 lb (681,000 kg) of cordite per month.^[25]

Factories, specifically "heavy industry" (Long, and Marland 2009) were important for the provision of munitions. Cordite factories typically employed women (Cook 2006) who put their lives at risk as they packed the shells.^{[citation needed]}

Production quantities

Large quantities of cordite were manufactured in both World Wars for use by the military.^[26]

Pre–World War I

Prior to World War I, most of the cordite used by the British Government was produced in its own factories. Immediately prior to World War I, between 6,000 and 8,000 tons per year of cordite were produced in the United Kingdom by private manufacturers; between 1,000 and 1,500 tons per year were made by Nobel's Explosives, at Ardeer.^[23] However, private industry had the capability to produce about 10,000 tons per year, with Ardeer able to produce some 3,000 tons of this total.^[23]

World War I

At the start of World War I, private industry in the UK was asked to produce 16,000 tons of cordite, and all the companies started to expand.

In 1910, Canadian Explosives Limited produced 3,000 lb (1,362 kg) of rifle cordite per month at its Beloeil factory, for the Quebec Arsenal. By November 1915 production had been expanded to 350,000 lb (159,000 kg) of cordite per month (approximately 1,900 tonnes per year).^[25] 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).^{[citation needed]}

Between wars

World War II

As noted above, in addition to its own facilities, the British Government had ICI Nobel set up a number of Agency Factories producing cordite in Scotland, Australia, Canada and South Africa.^{[citation needed]}

Citations

Bibliography

• Bowditch, M.R.; Hayward, L. (1996). A Pictorial Record of the Royal Naval Cordite Factory: Holton Heath. Wareham: Finial Publishing.
  ISBN 1-900467-01-1
  .
• Brown, David K.; McCallum, Iain (2001). "Ammunition Explosions in World War I". Warship International. XXXVIII (1). International Naval Research Organization: 58–69.
  ISSN 0043-0374
  .
• 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:
  ISBN 1-85074-718-0
  .
• Davis, Tenney L. (1943). The Chemistry of Powder and Explosives. Vol. II. New York: John Wiley & Sons.
• Hartcup, Guy (1970). The Challenge of War: Scientific and Engineering Contributions to World War Two. Newton Abbot:
  ISBN 0-7153-4789-6
  .
• Hogg, O.F.G. (1970). Artillery: its origin, heyday and decline. London: C Hurst and Company.
• Ministry of Munitions (1922). The Official History of the Ministry of Munitions Volume X The Supply of Munitions Part IV Gun Ammunition: Explosives.
• Reader, W.J. (1975). Imperial Chemical Industries: A History. Volume II; The First Quarter-Century 1926-1952. London:
  ISBN 0-19-215944-5
  .
• Schuck, H.; Sohlman, R. (1929). The Life of Alfred Nobel. London: William Heinemann.
• 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
  .
• Rotter, Andrew J. (2008). Hiroshima: The World's Bomb. Oxford: Oxford University Press.
  ISBN 978-0-19-280437-2
  .
• Zukas, John A.; Walters, William P. (2002). Explosives, Effects and Applications. Springer.

External links

Wikimedia Commons has media related to Cordite.

• AMMUNITION
• Sausalito News 2 June 1917 – California Digital Newspaper Collection