Carronade

From Wikipedia, the free encyclopedia

24-pounder carronade (140 mm)
24-pounder carronade (140 mm)
68-pounder British naval carronade
68-pounder British naval carronade

The carronade was a short smoothbore, cast iron cannon, developed for the Royal Navy by the Carron Company, an ironworks in Falkirk, Scotland, UK used from the 1770s to the 1860s.

The carronade was designed as a short-range naval weapon with a low muzzle velocity, and is said to have been invented by Lieutenant General Robert Melville in 1759 and developed by Charles Gascoigne, manager of the Carron Company from 1769 to 1779. It was adopted by the Royal Navy in 1779, and its early years was also known as a "gasconade" or "melvillade". The lower muzzle velocity of a carronade's round shot was intended to create many more of the deadly wooden splinters when hitting the structure of an enemy vessel, leading to its nickname, the smasher. However, the small powder charge of the carronade was only able to project a heavy cannonball over a relatively limited distance. The short barrel, low muzzle velocity and short range also increased the risk that a carronade would eject burning wadding onto nearby combustible materials, increasing the risk of fire.

Diagram of a carronade mounting
Diagram of a carronade mounting

A carronade was much shorter and a third to a quarter of the weight of an equivalent long gun: for example, a 32 pounder carronade weighed less than a ton, but a 32 pounder long gun weighed over 3 tons. Carronades were manufactured in the usual naval gun calibres (12, 18, 24, 32 and 42 pounders, but 6 pdr and 68 pdr versions are known), but they were not counted in a ship of the line's rated number of guns. As a result, the classification of Royal Navy vessels in this period can mislead, since they would often be carrying more pieces of ordnance than they were described as carrying.

Although the carronade, like other naval guns, was mounted with ropes to restrain the recoil, the details of the gun mounting were usually quite different. The carronade was typically mounted on a sliding, rather than wheeled, gun carriage, and elevation was achieved with a turnscrew, like field guns, rather than the quoins (wooden wedges) usual for naval guns. In addition, a carronade was usually mounted on a lug underneath the barrel, rather than the usual trunnions to either side. As a result, the carronade had an unusually high centre of gravity. Towards the end of the period of use, some carronades were fitted with trunnions to lower their centre of gravity, to create a variant known as the gunnade.

As a result of irregularities in the size of cannon balls and the difficulty of boring out gun barrels, there was usually a considerable gap (known as the windage) between the ball and the inside of the gun barrel. The windage of a cannon was often as much as a quarter of an inch and caused a considerable loss of projectile power. The manufacturing practices introduced by the Carron Company reduced the windage considerably. Despite the reduced windage, carronades had a much shorter range, typically a third to a half, than the equivalent long gun because they used a much smaller propellant charge (the chamber for the powder was smaller than the bore for the ball). However, typical naval tactics in the late 18th Century emphasised short-range broadsides, so the short range was not thought to be a problem: indeed, their much lighter weight allowed a ship to carry more carronades, or carronades of a larger calibre, than long guns, and carronades could be mounted on the upper decks, where heavy long guns could cause the ship to be top-heavy and unstable. Carronades also required a smaller gun crew, were faster to reload, and were easier to aim. HMS Victory used the two 68 pdr carronades which she carried on her forecastle to great effect at the Battle of Trafalgar, clearing the gun deck of the Bucentaure by firing a round shot and a keg of 500 musket balls through the Bucentaure's stern windows.

The carronade was initially very successful and widely adopted, and a few experimental ships (for example, HMS Glatton) were fitted with a carronade-only armament. However, the lack of range against an opponent who could keep well clear and still use his long guns led to the demise of the carronade. In the 1810s and 1820s, greater emphasis was placed on the accuracy of long-range gunfire, and less on the weight of a broadside. Indeed, Captain David Porter of USS Essex complained when his 12 pounder long guns were replaced with 32 pounder carronades. The carronade disappeared from the Royal Navy from the 1850s after the development of steel, jacketed cannon by William George Armstrong and Joseph Whitworth. Nevertheless, carronades were used in the American Civil War in the 1860s.


[edit] References