68-pounder gun
Encyclopedia
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
muzzle-loading
gun manufactured in several weights, the most common being 95 long cwt (4,826.2 kg), and fired projectiles of 68 lb (30.8 kg). Colonel William Dundas designed the 112 cwt version in 1841 and it was cast the following year. The most common variant, weighing 95 cwt, dates from 1846. It entered service with the Royal Artillery
and the Royal Navy
and saw active service with both arms during the Crimean War
. 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 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.
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 in Bradford
in 1847 and entered service soon after. Like numerous cannon before it
, it was a cast iron
smoothbore
loaded from the muzzle
. The cannon was relatively cheap to produce – the Royal Commission on the Defence of the United Kingdom
estimated that each cannon cost approximately £167. Over 2000 were cast before 1861 and its exceptional durability, range and accuracy earned it a reputation as the finest smoothbore cannon ever made.
The 68-pounder had an effective range of approximately 3000 yd (2,743.2 m), however at its maximum elevation of 15 degrees it had a maximum range of 3620 yd (3,310.1 m), a distance that the projectile would cover in 15 seconds. With a 16 lb (7.3 kg) powder charge (the "far" charge, although the gun was proofed to 25 lb charges) the cannon fired a 68 lb (30.8 kg) solid shot at a muzzle velocity of 1579 ft/s (481.3 m/s).
The cannon could fire solid shot
, explosive shells
, grapeshot
, case shot
and molten iron shells (thin walled shells filled with molten iron). Although the cannon's barrel bore was 8.12 inches (20.6 cm), both shot and shells were 7.92 inches (20.1 cm) in diameter. This allowed a windage gap of 0.1 in (0.254 cm) 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 67 lb (30.4 kg), wrought iron shot and steel shot weighed 72 lb (32.7 kg), and chilled steel weighed 68 lb (30.84428116 kg). It was estimated that one 68-pound shot had the destructive power equivalent to five 32-pound shot. The explosive shells were primed with 4 lb (1.8 kg) of gunpowder. They were fitted with simple fuses
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
to ensure the fuse faced away from the charge.
On land a minimum crew of nine men (usually commanded by a non-commissioned officer
) 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 on account of the fact that 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.
warships of different sizes such as , , , and the Conqueror-class ships of the line
. Several of these ships saw action during the Crimean War
where the 68-pounder was used extensively during the Siege of Sevastopol. 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 Warrior-class battleships
and . Originally it was intended to fit forty 68-pounders, primarily on one gun deck
, but this specification changed during their building and they were finally equipped with twenty-six 68-pounders (13 on each side). Alongside these, the ships were equipped with new rifled breech loading
Armstrong gun
s 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. 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
and the Armstrong's wrought iron
construction were retained, leading to a new design of artillery piece – rifled muzzle loaders.
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 6.3 inches (16 cm) and were known as a RML 68-pounder, or officially as the
RML 80-pounder 5 ton. With a 10 lb (4.5 kg) powder charge they could fire an 80 lb (36.3 kg) projectile at a muzzle velocity of 1240 feet per second (378 m/s). They were deployed as coast defence and garrison artillery around the British Empire and remained in service until eventually declared obsolete in 1921.
Smoothbore
A smoothbore weapon is one which has a barrel without rifling. Smoothbores range from handheld firearms to powerful tank guns and large artillery mortars.-History of firearms and rifling:...
muzzle-loading
Muzzleloader
A muzzleloader is any firearm into which the projectile and usually the propellant charge is loaded from the muzzle of the gun . This is distinct from the more popular modern designs of breech-loading firearms...
gun manufactured in several weights, the most common being 95 long cwt (4,826.2 kg), and fired projectiles of 68 lb (30.8 kg). Colonel William Dundas designed the 112 cwt version in 1841 and it was cast the following year. The most common variant, weighing 95 cwt, dates from 1846. It entered service with the Royal Artillery
Royal Artillery
The Royal Regiment of Artillery, commonly referred to as the Royal Artillery , is the artillery arm of the British Army. Despite its name, it comprises a number of regiments.-History:...
and the Royal Navy
Royal Navy
The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...
and saw active service with both arms during the Crimean War
Crimean War
The Crimean War was a conflict fought between the Russian Empire and an alliance of the French Empire, the British Empire, the Ottoman Empire, and the Kingdom of Sardinia. The war was part of a long-running contest between the major European powers for influence over territories of the declining...
. 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
Rifling
Rifling is the process of making helical grooves in the barrel of a gun or firearm, which imparts a spin to a projectile around its long axis...
and breech loading 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
HMS Warrior (1860)
HMS Warrior was the first iron-hulled, armour-plated warship, built for the Royal Navy in response to the first ironclad warship, the French Gloire, launched a year earlier....
, 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 lineShip of the line
A ship of the line was a type of naval warship constructed from the 17th through the mid-19th century to take part in the naval tactic known as the line of battle, in which two columns of opposing warships would manoeuvre to bring the greatest weight of broadside guns to bear...
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 in Bradford
Bradford
Bradford lies at the heart of the City of Bradford, a metropolitan borough of West Yorkshire, in Northern England. It is situated in the foothills of the Pennines, west of Leeds, and northwest of Wakefield. Bradford became a municipal borough in 1847, and received its charter as a city in 1897...
in 1847 and entered service soon after. Like numerous cannon before it
Naval artillery in the Age of Sail
Naval artillery in the Age of Sail encompasses the period of roughly 1571-1863: when large, sail-powered wooden naval warships dominated the high seas, mounting a bewildering variety of different types and sizes of cannon as their main armament. By modern standards, these cannon were extremely...
, it was a cast iron
Cast iron
Cast iron is derived from pig iron, and while it usually refers to gray iron, it also identifies a large group of ferrous alloys which solidify with a eutectic. The color of a fractured surface can be used to identify an alloy. White cast iron is named after its white surface when fractured, due...
smoothbore
Smoothbore
A smoothbore weapon is one which has a barrel without rifling. Smoothbores range from handheld firearms to powerful tank guns and large artillery mortars.-History of firearms and rifling:...
loaded from the muzzle
Muzzleloader
A muzzleloader is any firearm into which the projectile and usually the propellant charge is loaded from the muzzle of the gun . This is distinct from the more popular modern designs of breech-loading firearms...
. The cannon was relatively cheap to produce – the Royal Commission on the Defence of the United Kingdom
Royal Commission on the Defence of the United Kingdom
In 1859 Lord Palmerston instigated the Royal Commission on the Defence of the United Kingdom because of serious concerns that France might attempt to invade the UK...
estimated that each cannon cost approximately £167. Over 2000 were cast before 1861 and its exceptional durability, range and accuracy earned it a reputation as the finest smoothbore cannon ever made.
Operation
The gun was a traditional muzzleloader; it needed to be loaded from the end of the barrel. 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. 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).The 68-pounder had an effective range of approximately 3000 yd (2,743.2 m), however at its maximum elevation of 15 degrees it had a maximum range of 3620 yd (3,310.1 m), a distance that the projectile would cover in 15 seconds. With a 16 lb (7.3 kg) powder charge (the "far" charge, although the gun was proofed to 25 lb charges) the cannon fired a 68 lb (30.8 kg) solid shot at a muzzle velocity of 1579 ft/s (481.3 m/s).
The cannon could fire solid shot
Round shot
Round shot is a solid projectile without explosive charge, fired from a cannon. As the name implies, round shot is spherical; its diameter is slightly less than the bore of the gun it is fired from.Round shot was made in early times from dressed stone, but by the 17th century, from iron...
, explosive shells
Shell (projectile)
A shell is a payload-carrying projectile, which, as opposed to shot, contains an explosive or other filling, though modern usage sometimes includes large solid projectiles properly termed shot . Solid shot may contain a pyrotechnic compound if a tracer or spotting charge is used...
, grapeshot
Grapeshot
In artillery, a grapeshot is a type of shot that is not a one solid element, but a mass of small metal balls or slugs packed tightly into a canvas bag. It was used both in land and naval warfare. When assembled, the balls resembled a cluster of grapes, hence the name...
, case shot
Canister shot
Canister shot is a kind of anti-personnel ammunition used in cannons. It was similar to the naval grapeshot, but fired smaller and more numerous balls, which did not have to punch through the wooden hull of a ship...
and molten iron shells (thin walled shells filled with molten iron). Although the cannon's barrel bore was 8.12 inches (20.6 cm), both shot and shells were 7.92 inches (20.1 cm) in diameter. This allowed a windage gap of 0.1 in (0.254 cm) around the projectile; enough to aid the loading process, but not enough to seriously diffuse the propellant gasses.
Fuse (explosives)
In an explosive, pyrotechnic device or military munition, a fuse is the part of the device that initiates function. In common usage, the word fuse is used indiscriminately...
that were ignited by the flash of the charge – early wooden fuses were eventually replaced by more reliable fuses designed by Captain Edward Boxer
Edward Boxer
Edward Boxer was an English Royal Navy officer, who reached the rank of rear-admiral.-Life:Boxer entered the navy in 1798. After eight years' junior service, mostly with Captain Charles Brisbane, and for some short time in the Ocean, Lord Collingwood's flagship, he was confirmed, 8 June 1807, as...
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
A sabot is a device used in a firearm or cannon to fire a projectile, such as a bullet, that is smaller than the bore diameter, or which must be held in a precise position. The term is also applied to a battery stub case, a device used similarly to make a small electrical battery usable in a...
to ensure the fuse faced away from the charge.
On land a minimum crew of nine men (usually commanded by a non-commissioned officer
Non-commissioned officer
A non-commissioned officer , called a sub-officer in some countries, is a military officer who has not been given a commission...
) 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 on account of the fact that 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 NavyRoyal Navy
The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...
warships of different sizes such as , , , and the Conqueror-class ships of the line
Conqueror class ship of the line
The Conqueror-class ships of the line were a class of two 101-gun first rate screw propelled ships designed by the Surveyor’s Department for the Royal Navy.-Design:...
. Several of these ships saw action during the Crimean War
Crimean War
The Crimean War was a conflict fought between the Russian Empire and an alliance of the French Empire, the British Empire, the Ottoman Empire, and the Kingdom of Sardinia. The war was part of a long-running contest between the major European powers for influence over territories of the declining...
where the 68-pounder was used extensively during the Siege of Sevastopol. Along with 32-pounders and Lancaster guns
68-Pounder Lancaster gun
68-Pounder Lancaster guns were a rifled muzzle-loading cannon that fired a 68 pound shell. They were fitted in pairs to the Arrow-class gunvessel. The cannon was designed with an oval bore and had a range of about 6500 yards. The gun suffered from a tendency to burst....
they were taken from their ship mountings and dragged up to siege batteries by the Naval Brigade
Naval Brigade
A Naval Brigade is a body of sailors serving in a ground combat role to augment land forces.-Royal Navy:Within the Royal Navy, a Naval Brigade is a large temporary detachment of Royal Marines and of seamen from the Royal Navy formed to undertake operations on shore, particularly during the mid- to...
, 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
Aetna class ironclad floating battery
The Aetna-class ironclad floating batteries were built during the Crimean War for the attack of Russian coastal fortifications.Britain and France each laid down five of these coastal attack vessels in 1854. The French used three of their batteries in 1855 against the defences at Kinburn on the...
, although these had little impact on the war.
Warrior class battleship
The Warrior class ironclads were a class of two warships built for the Royal Navy between 1859 and 1862, the first ocean-going ironclads with iron hulls ever constructed. The ships were designed as armoured frigates in response to an invasion scare sparked by the launch of the and her three...
and . Originally it was intended to fit forty 68-pounders, primarily on one gun deck
Gun deck
The term gun deck originally referred to a deck aboard a ship that was primarily used for the mounting of cannon to be fired in broadsides. However, on many smaller vessels such as frigates and unrated vessels the upper deck, forecastle and quarterdeck bore all of the cannons but were not referred...
, but this specification changed during their building and they were finally equipped with twenty-six 68-pounders (13 on each side). Alongside these, the ships were equipped with new rifled breech loading
Rifled breech loader
A rifled breech loader is an artillery piece which, unlike the smooth-bore cannon and rifled muzzle loader which preceded it, has rifling in the barrel and is loaded from the breech at the rear of the gun....
Armstrong gun
Armstrong Gun
The term Armstrong Gun was primarily used to describe the unique design of the rifled breech-loading field and heavy guns designed by Sir William Armstrong and manufactured in England from 1855 by the Elswick Ordnance Company and the Royal Arsenal at Woolwich...
s of two types; 7 inch and 40 pounders
RBL 40 pounder Armstrong gun
The Armstrong RBL 40 pounder gun was an early attempt to use William Armstrong's new and innovative breechloading mechanism for medium artillery.-Design history:...
. 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. 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
RML 7 inch gun
The RML 7 inch guns were various designs of medium-sized rifled muzzle-loading guns used to arm small-medium sized British warships in the late 19th century, and some were used ashore for coast defence.-Design and history:...
and a RML 64 pounder 64 cwt gun
RML 64 pounder 64 cwt gun
The RML 64 pounder 64 cwt gun was a Rifled, Muzzle Loading naval, field or fortification artillery gun manufactured in England in the 19th century, which fired a projectile weighing approximately...
.
On land the 68-pounder was used extensively in British coastal defences constructed during the 1850s - notably at forts like Gomer
Fort Gomer
Fort Gomer was one of the Palmerston Forts, in Gosport, England, the southernmost and first-built polygonal land fort in the defence line to the west of Gosport. It was located on land immediately to the west of the present Gomer Lane. Fort Gomer was the most southerly fort in the line of five...
and Elson defending Portsmouth, and Forts Victoria
Fort Victoria (Isle of Wight)
Fort Victoria was a single tier battery with defensible barracks west of Yarmouth, Isle of Wight, England, built in the 1850s, later used as a submarine mining centre and training area for military purposes....
, Albert
Fort Albert
Fort Albert is a tower fort nestling under the cliffs west of Fort Victoria on the Isle of Wight, England. It was also known as Cliff End Fort, named after the Northern extremity of Colwell Bay .-History:...
and Freshwater Redoubt
Freshwater Redoubt
Freshwater Redoubt, also known as Fort Redoubt is an old Palmerston fort built in Freshwater Bay on the western end of the Isle of Wight. Construction work for the fort began in 1855 and was completed in 1856. It was finally sold in 1928 and has now been converted into a private residence....
defending the Needles Passage.
The 1859 Royal Commission envisaged arming the numerous new forts
Palmerston Forts
The Palmerston Forts are a group of forts and associated structures, around the coast of Britain.The forts were built during the Victorian period on the recommendations of the 1860 Royal Commission on the Defence of the United Kingdom, following concerns about the strength of the French Navy, and...
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
Rifling is the process of making helical grooves in the barrel of a gun or firearm, which imparts a spin to a projectile around its long axis...
and the Armstrong's wrought iron
Wrought iron
thumb|The [[Eiffel tower]] is constructed from [[puddle iron]], a form of wrought ironWrought iron is an iron alloy with a very low carbon...
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. 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 PalliserWilliam Palliser
Major Sir William Palliser CB MP was an Irish-born politician and inventor, Member of Parliament for Taunton from 1880 until his death.-Early life:...
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 6.3 inches (16 cm) and were known as a RML 68-pounder, or officially as the
RML 80-pounder 5 ton. With a 10 lb (4.5 kg) powder charge they could fire an 80 lb (36.3 kg) projectile at a muzzle velocity of 1240 feet per second (378 m/s). They were deployed as coast defence and garrison artillery around the British Empire and remained in service until eventually declared obsolete in 1921.
See also
- 68-Pounder Lancaster gun68-Pounder Lancaster gun68-Pounder Lancaster guns were a rifled muzzle-loading cannon that fired a 68 pound shell. They were fitted in pairs to the Arrow-class gunvessel. The cannon was designed with an oval bore and had a range of about 6500 yards. The gun suffered from a tendency to burst....
- a gun of the same weight and calibre, featuring an early design of rifling.