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The 68-pounder cannon was an artillery piece designed and used by the British Armed Forces in the mid-19th century. The cannon was a
smoothbore A smoothbore weapon is one that has a barrel without rifling. Smoothbores range from handheld firearms to powerful tank guns and large artillery mortars. Some examples of smoothbore weapons are muskets, blunderbusses, and flintlock pistols. ...
muzzle-loading A muzzleloader is any firearm in which the user loads the projectile and the propellant charge into the muzzle end of the gun (i.e., from the forward, open end of the gun's barrel). This is distinct from the modern designs of breech-loading fire ...
gun manufactured in several weights firing projectiles of . Colonel William Dundas designed the 112 cwt version in 1841 which was cast the following year. The most common variant, weighing , dates from 1846. It entered service with the
Royal Artillery The Royal Regiment of Artillery, commonly referred to as the Royal Artillery (RA) and colloquially known as "The Gunners", is one of two regiments that make up the artillery arm of the British Army. The Royal Regiment of Artillery comprises t ...
and the
Royal Navy The Royal Navy (RN) is the naval warfare force of the United Kingdom. It is a component of His Majesty's Naval Service, and its officers hold their commissions from the King of the United Kingdom, King. Although warships were used by Kingdom ...
and saw active service with both arms during the
Crimean War The Crimean War was fought between the Russian Empire and an alliance of the Ottoman Empire, the Second French Empire, the United Kingdom of Great Britain and Ireland, and the Kingdom of Sardinia (1720–1861), Kingdom of Sardinia-Piedmont fro ...
. Over 2,000 were made and it gained a reputation as the finest smoothbore cannon ever made. The gun was produced at a time when new rifled and
breech loading Breech may refer to: * Breech (firearms), the opening at the rear of a gun barrel where the cartridge is inserted in a breech-loading weapon * breech, the lower part of a pulley block * breech, the penetration of a boiler where exhaust gases leave ...
guns were beginning to make their mark on artillery. At first the 68-pounder's reliability and power meant that it was retained even on new warships such as HMS ''Warrior'', but eventually new rifled muzzle loaders made all smoothbore muzzle-loading guns obsolete. However, the large surplus stocks of 68-pounders were given new life when converted to take rifled projectiles; the cannon remained in service and was not declared obsolete until 1921.


Design

The cannon was designed in response to the need for heavier weaponry as armour on
ships of the line A ship of the line was a type of naval warship constructed during the Age of Sail from the 17th century to the mid-19th century. The ship of the line was designed for the naval tactic known as the line of battle, which involved the two column ...
improved. Colonel William Dundas, the government's Inspector of Artillery between 1839 and 1852, designed the cannon in 1846. It was cast by the
Low Moor Iron Works The Low Moor Ironworks was a wrought iron foundry established in 1791 in the village of Low Moor, Bradford, Low Moor about south of Bradford in Yorkshire, England. The works were built to exploit the high-quality iron ore and low-sulphur coal fou ...
in
Bradford Bradford is a city status in the United Kingdom, city in West Yorkshire, England. It became a municipal borough in 1847, received a city charter in 1897 and, since the Local Government Act 1972, 1974 reform, the city status in the United Kingdo ...
in 1847 and entered service soon after. Like numerous cannon before it, it was a
cast iron Cast iron is a class of iron–carbon alloys with a carbon content of more than 2% and silicon content around 1–3%. Its usefulness derives from its relatively low melting temperature. The alloying elements determine the form in which its car ...
smoothbore A smoothbore weapon is one that has a barrel without rifling. Smoothbores range from handheld firearms to powerful tank guns and large artillery mortars. Some examples of smoothbore weapons are muskets, blunderbusses, and flintlock pistols. ...
loaded from the muzzle.Hogg, p. 37 The cannon was relatively cheap to produce – the Royal Commission on the Defence of the United Kingdom estimated that each cannon cost approximately £167.Hogg, p. 25 (2010 : £12,645). Over 2000 were cast before 1861 and its exceptional durability, range and accuracy earned it a reputation as the finest smoothbore cannon ever made.Lambert, p. 82


Operation

The gun was a traditional muzzleloader; it needed to be loaded from the front end of the barrel.Cantwell, p. 21 Before it could be loaded the bore of the barrel was cleaned with a sponge, after which a propellant charge (gunpowder in a cloth bag) was rammed down into the breech. This was followed by a projectile, often encased in wadding.Winton (1987), p. 30 The gun was primed (using a metal spike inserted through the vent that pierced the charge), and fired using a percussion cap (which ignited the charge and forced the projectile out of the barrel).Cantwell, p. 28 The estimated rate of fire of this weapon was between 55 and 70 seconds, though loading speed could be expected to fall off as crew became fatigued. The 68-pounder had an effective range of approximately , however at its maximum elevation of 15 degrees it had a maximum range of , a distance that the projectile would cover in 15 seconds. With a powder charge (the "far" charge, although the gun was proofed to 25 lb charges)Lambert, pp. 86–87 the cannon fired a solid shot at a muzzle velocity of . The cannon could fire
solid shot A round shot (also called solid shot or simply ball) is a solid spherical projectile without explosive charge, launched from a gun. Its diameter is slightly less than the caliber, bore of the gun barrel, barrel from which it is shot. A round s ...
, explosive shells,
grapeshot In artillery, a grapeshot is a type of ammunition that consists of a collection of smaller-caliber round shots packed tightly in a canvas bag and separated from the gunpowder charge by a metal wadding, rather than being a single solid projectile ...
, case shot and "Martins Liquid Iron Shell" (thin walled shells filled with molten iron, intended to serve as
heated shot Heated shot or hot shot is round shot that is heated before firing from muzzle-loading cannons, for the purpose of setting fire to enemy warships, buildings, or equipment. The use of heated shot dates back centuries. It was a powerful weapon agai ...
). Although the cannon's barrel bore was , both shot and shells were in diameter. This allowed a
windage In aerodynamics, firearms ballistics, and automobiles, windage is the effects of some fluid, usually air (e.g., wind) and sometimes liquids, such as oil. Aerodynamics Windage is a force created on an object by friction when there is relative m ...
gap of around the projectile; enough to aid the loading process, but not enough to seriously diffuse the propellant gasses. The official weight of the shot was listed at 68 lbs but in reality this varied according to the material of the shot itself; cast iron shot weighed , wrought iron shot and steel shot weighed , and chilled steel weighed . It was estimated that one 68-pound shot had the destructive power equivalent to five 32-pound shot. The explosive shells were primed with of gunpowder. They were fitted with simple
fuses Munitions, Fuse or FUSE may refer to: Devices * Fuse (electrical), a device used in electrical systems to protect against excessive current ** Fuse (automotive), a class of fuses for vehicles * Fuse (hydraulic), a device used in hydraulic systems ...
that were ignited by the flash of the charge – early wooden fuses were eventually replaced by more reliable fuses designed by Captain Edward Boxer in 1849. The gun crew still had to gauge the best length of fuse for the range they were firing – ideally the shell should explode just before hitting its target. To prevent the shell exploding in the barrel it was fitted with a
sabot Sabot may refer to: * Sabot (firearms), disposable supportive device used in gunpowder ammunitions to fit/patch around a sub-caliber projectile * Sabot (shoe), a type of wooden shoe People * Dick Sabot (1944–2005), American economist and bus ...
to ensure the fuse faced away from the charge. On land a minimum crew of nine men (usually commanded by a
non-commissioned officer A non-commissioned officer (NCO) is an enlisted rank, enlisted leader, petty officer, or in some cases warrant officer, who does not hold a Commission (document), commission. Non-commissioned officers usually earn their position of authority b ...
) was required to fire the gun, which was normally mounted on a traversing gun carriage. On board a ship the gun crew could be doubled to 18 men who needed to traverse the gun carriage by hand, using hand spikes and rope tackles. The extra crew was because sailing ships usually only fired their cannon from one side of the deck. In the unlikely event of both sides being in action at once, nine men would be detached to man the gun opposite. In both cases the gun was elevated using wooden wedges driven under the breech of the barrel by brute force. It was aimed using an advanced hexagonal sighting mechanism marked with the elevation on one face and the gun's range (according to different weights of cartridge charges) on the other five faces.


Service

The cannon was put to use both on land and at sea. It was fitted to numerous
Royal Navy The Royal Navy (RN) is the naval warfare force of the United Kingdom. It is a component of His Majesty's Naval Service, and its officers hold their commissions from the King of the United Kingdom, King. Although warships were used by Kingdom ...
warships of different sizes such as , , , and the ''Conqueror''-class ships of the line. Several of these ships saw action during the
Crimean War The Crimean War was fought between the Russian Empire and an alliance of the Ottoman Empire, the Second French Empire, the United Kingdom of Great Britain and Ireland, and the Kingdom of Sardinia (1720–1861), Kingdom of Sardinia-Piedmont fro ...
where the 68-pounder was used extensively during the Siege of Sevastopol.Winton (2001), p. 112 Along with 32-pounders and Lancaster guns they were taken from their ship mountings and dragged up to siege batteries by the Naval Brigade, from where they regularly bombarded Russian positions for the next year. The cannon was also fitted in large numbers to the ''Aetna''-class ironclad floating batteries, although these had little impact on the war. Most notably the 68-pounder was fitted to the s and . Originally it was intended to fit forty 68-pounders, primarily on one
gun deck The term gun deck used to refer to a deck aboard a ship that was primarily used for the mounting of cannon A cannon is a large-caliber gun classified as a type of artillery, which usually launches a projectile using explosive chemical prope ...
, but this specification changed during their building and they were finally equipped with twenty-six 68-pounders (13 on each side).Winton (1987), p. 6 Alongside these, the ships were equipped with new rifled breech loading Armstrong guns of two types; 7 inch and 40 pounders. Although the Armstrong guns represented a new direction in artillery, the breech loading mechanism meant that they were unable to withstand the explosion of a heavy cartridge. Smaller cartridge charges were therefore required and the gun's muzzle velocity suffered as a result.Hogg, p. 37 Ironically the Armstrong Guns were therefore incapable of penetrating the armour fitted to the ''Warrior''-class ships, while the 68-pounder (with its high muzzle velocity) could. As late as 1867 it was planned to fit the new s with 68-pounders, but they were instead completed with a RML 7 inch gun and a RML 64 pounder 64 cwt gun. On land the 68-pounder was used extensively in British coastal defences constructed during the 1850s - notably at forts like Gomer and Elson defending Portsmouth, and Forts Victoria, Albert and Freshwater Redoubt defending the Needles Passage. The 1859 Royal Commission envisaged arming the numerous new forts they proposed with the 68-pounder cannon and costed for them accordingly. The introduction of the Armstrong gun initially led many to think that weapon would be used instead, but whilst the forts were being built, the Armstrong gun's weaknesses were exposed and the military reverted to using muzzle loaded weapons. However, the advantages of
rifling Rifling is the term for helical grooves machined into the internal surface of a firearms's barrel for imparting a spin to a projectile to improve its aerodynamic stability and accuracy. It is also the term (as a verb) for creating such groov ...
and the Armstrong's
wrought iron Wrought iron is an iron alloy with a very low carbon content (less than 0.05%) in contrast to that of cast iron (2.1% to 4.5%), or 0.25 for low carbon "mild" steel. Wrought iron is manufactured by heating and melting high carbon cast iron in an ...
construction were retained, leading to a new design of artillery piece – rifled muzzle loaders.


Conversion to rifled muzzle loader

The introduction of rifled muzzle loaders (also classed as RMLs) rendered smoothbore guns largely obsolete.Hogg, p.39 However, the 68-pounder and other smoothbores still existed in large numbers and various attempts were made to adapt the guns to fire new projectiles. Eventually Captain
William Palliser Sir William Palliser CB MP (18 June 1830 – 4 February 1882) was an Irish-born politician and inventor, Member of Parliament for Taunton from 1880 until his death. Early life Born in Dublin on 18 June 1830, Palliser was the fourth of the eig ...
patented a method of boring out the gun barrel and inserting a wrought iron rifled liner. This allowed rifled shot and shells to be fired from old smoothbore cannon and experiments revealed that it made them even more powerful than they had been before. Introduced in 1872, 68-pounders adapted in this way had a calibre of and were known as a RML 68-pounder, or officially as the RML 80-pounder 5 ton. With a powder charge they could fire an projectile at a muzzle velocity of . They were deployed as coast defence and garrison artillery around the British Empire and remained in service until eventually declared obsolete in 1921. At least two 68 pounders were converted to RML guns, firing a or double shot.


Surviving examples

* Southsea Castle *
Carrickfergus Castle Carrickfergus Castle (from the Irish ''Carraig Ḟergus'' or "cairn of Fergus", the name "Fergus" meaning "strong man") is a Norman castle in Northern Ireland, situated in the town of Carrickfergus in County Antrim, on the northern shore of B ...
* Fort Nelson, Hampshire, Royal Amouries Collection *
Bradleys Head Bradleys Head is a headland protruding from the north shore of Sydney Harbour, within the metropolitan area of Sydney, New South Wales, Australia. It is named after the First Fleet naval officer William Bradley. The original Aboriginal inhabi ...
, Sydney Harbour, Australia * Flagstaff Hill Fort, NSW, Australia
Two guns at Port Fairy, Victoria, Australia - from Flickr
* Garden Island Dockyard, NSW, Sydney, Australia *
Halifax Citadel Citadel Hill is a National Historic Sites of Canada, National Historic Site in Halifax, Nova Scotia, Canada. Four fortifications have been constructed on Citadel Hill since the city was founded by the British in 1749, and were referred to as For ...
, Canada *Daylesford Botanical Gardens, Victoria Australia.


See also

* 68-pounder Lancaster gun - a gun of the same weight and calibre, featuring an early design of rifling.


Notes


References


Bibliography


Treatise on the Construction and Manufacture of Ordnance in the British Service. Royal Gun Factory, 1877
* *General Sir Howard Douglas
"A Treatise on Naval Gunnery". Fifth edition, revised. published by John Murray, London, 1860
* * * *


External links


Handbook for the 80-pr rifled M.L. converted gun of 5 tons on sliding carriage Land service 1883
at State Library of Victoria {{VictorianEraBritishNavalWeapons Naval guns of the United Kingdom Artillery of the United Kingdom Coastal artillery Victorian-era weapons of the United Kingdom