Carronade The carronade is a short smoothbore , cast iron cannon , which was used by the Royal Navy and first produced by the Carron Company , an ironworks in Falkirk , Scotland , UK . It was used from the 1770s to the 1850s . Its main function was to serve as a powerful , short - range anti - ship and anti - crew weapon . While considered very successful early on , carronades eventually disappeared as rifled naval artillery changed the shape of the shell and led to fewer and fewer close - range engagements . History . The carronade was designed as a short - range naval weapon with a low muzzle velocity for merchant ships , which found a niche role on warships . It was produced by the Carron ironworks and at first sold as a system with the gun , mounting and shot all together . The standard package of shot per gun was 25 roundshot , 15 barshot , 15 double - headed shot , 10 " single " grapeshot and 10 " single " canister shot . Single meant the shot weighed the same as the roundshot , some other canister and grapeshot were also included which weighed one and a half times the roundshot . The advantages for merchant ships are described in an advertising pamphlet of 1779 . Production of both shot and gun by the same firm immediately allowed a reduction in the windage , the gap between the bore of the gun and the diameter of the ball . The mounting , attached to the side of the ship on a pivot , took the recoil on a slider . The reduced recoil did not alter the alignment of the gun . The smaller gunpowder charge reduced the guns ' heating in action . The pamphlet advocated the use of woollen cartridges , which , although more expensive , eliminated the need for wadding and worming . Simplifying gunnery for comparatively untrained merchant seamen in both aim and reloading was part of the rationale for the gun . The replacement of trunnions by a bolt underneath , to connect the gun to the mounting , reduced the width of the carriage enhancing the wide angle of fire . A merchant ship would almost always be running away from its target , so a wide angle of fire was much more important than on a warship . A carronade weighed a quarter as much and used a quarter to a third of the gunpowder charge for a long gun firing the same cannonball . Its invention is variously ascribed to Lieutenant General Robert Melville in 1759 , or to Charles Gascoigne , manager of the Carron Company from 1769 to 1779 . In its early years the weapon was sometimes called a " mellvinade " or alternatively , a " gasconade " . The carronade can be seen as the culmination of an evolutionary process of naval guns reducing the barrel length and gunpowder charge . The Carron Company was already selling a " new light - constructed " gun , two - thirds of the weight of the standard naval gun and charged with one sixth of the weight of ball in powder before it introduced the carronade , which further halved the gunpowder charge . The reduced charge allowed carronades to have a shorter length and much lighter weight than long guns . Inside the gun barrel , increasing the size of the bore , and ball , reduces the required length of barrel . The force acting on the ball is proportional to the square of the diameter while the mass of the ball rises by the cube , acceleration is slower ; the barrel can be shorter and therefore lighter . Long guns were also excessively heavy in comparison to a carronade because they were over - specified , being capable of being double shotted whereas to do this in a carronade was dangerous . A ship could carry more carronades , or carronades of a larger caliber , 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 , which was very important for merchant ships , and they were faster to reload . Carronades initially became popular on British merchant ships during the American Revolutionary War . A lightweight gun that needed only a small gun crew and was devastating at short range was a weapon well suited to defending merchant ships against French and American privateer s . In the Action of 4 September 1782 , the impact of a single carronade broadside fired at close range by the frigate HMS " Rainbow " under Henry Trollope caused a wounded French captain to capitulate and surrender the " Hebe " after a short fight . The Royal Navy was initially reluctant to adopt the guns , mainly due to mistrust of the Carron Company , which had developed a reputation for incompetence and commercial sharp practice . Carronades were not even counted in numbering the guns of a ship . It was Lord Sandwich who eventually started mounting them in place of the light guns on the forecastle and quarterdeck of ships . They soon proved their effectiveness in battle . French gun foundries were unable to produce equivalents for twenty years , so carronades gave British warships a significant tactical advantage during the latter part of the 18th century — though French ships mounted another type of weapon in the same role , the " obusier de vaisseau " . HMS " Victory " used the two 68 - pounder 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 " and HMS " Rainbow " ) were fitted with a carronade - only armament . " Glatton " , a fourth - rate ship with 56 guns , had a more destructive broadside than HMS " Victory " , a first - rate ship with 100 guns . Although " Glatton " and " Rainbow " were both successful in battle , the carronade ' s lack of range against an opponent who could keep well clear and still use his long guns was an arguable tactical disadvantage of this arrangement . In the 1810s and 1820s , tactics started to place a greater emphasis on the accuracy of long - range gunfire , and less on the weight of a broadside . Indeed , Captain David Porter of USS " Essex " complained when the navy replaced his 12 - pounder long guns 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 . Carronades were nevertheless still used in the American Civil War in the 1860s . The last known use of a carronade in conflict was during the First Boer War . In the siege of Potchefstroom the Boers used ' Ou Griet ' , an antique carronade mounted on a wagon axle , against the British fort . Design . The original design of the carronade included a different type of mounting on a wooden carriage where the cannon itself had a projecting loop on the bottom that was pinned to the gun carriage , which was fastened to the side of the ship , with a pivoting mounting which allowed the gun to be rotated while rearward recoil was contained , sometimes with a slider carriage . In some versions a wedge was placed underneath the chamber to control elevation while in later versions an elevating screw was used Carronades had a chamber one caliber smaller than the bore – for example , an 18 - pounder carronade had its chamber bored equal to a 12 - pounder . This was partly to reduce the weight of the cannon , but also had the effect of reducing the velocity of the cannonball and range to which it could fire , relative to a gun firing the same weight of shot , and all other things being equal . However , one factor mitigating the deficiency in range is that carronades could be bored with a much tighter windage than long guns . This meant that more of the propellant went to moving the shot , rather than bypassing it . Naval artillery during the Age of Sail simply was not accurate , regardless of whether the cannon was a gun or a carronade . Almost all barrels were smoothbore , not rifled , and tolerances on everything from the actual roundness and straightness of the barrel and shot size in relation to the bores ( windage ) had wide variations . Sights were rudimentary or non - existent and elevation was controlled by wedges and guesswork . As a result , effective or decisive naval battles were generally fought at ranges under 100 yards where the carronade ' s heavier ball was useful and its shorter range was not a huge problem . While technological improvements changed the capabilities of naval armament by the nineteenth century , muzzle - loading smoothbore cannon were still not very accurate . As a result , shipborne cannon counted on the effect of rapid broadsides at short range . The carronade could make a significant contribution to the weight of a broadside . Ordnance . A carronade was much shorter and a third to a quarter of the weight of an equivalent long gun : a 32 - pounder carronade , for example , weighed less than a ton , but a 32 - pounder long gun weighed over 3 tons . Carronades were manufactured in the usual naval gun sizes : 6 - , 12 - , 18 - , 24 - , 32 - , and 42 - pounders , and 68 - pounder versions are known . The smaller carronades served in three roles . First , they often constituted the entire armament of unrated vessels . For instance , the " Ballahoo " - and " Cuckoo " - class schooners were armed only with four 12 - pounder carronades . Second , gunboats , such as those that the Americans deployed at the Battle of Lake Borgne often had one large 18 - , 24 - , or 32 - pounder gun forward on a pivot , and two smaller carronades aft . Lastly , larger vessels carried a few 12 - , 18 - , or 24 - pounders , to arm their ship ' s boats — the cutters , pinnaces , launches , barges , and the like — to give them firepower for boat actions . For instance , each of the 42 larger British boats at the Battle of Lake Borgne carried a carronade in its bows ; only the three gigs were unarmed . At the other end , even a quite small vessel might carry the 68 - pounders . For instance , Commander William Layman of the ill - fated " Cruizer " - class brig sloop HMS " Raven " replaced her two forward 6 - pounder guns and 32 - pounder carronades with a single 68 - pounder on a pivot , and then did the same with two of the aft 32 - pounder carronades . By doing this he replaced 70 pounds of broadside with 136 pounds ( assuming that both 68 - pounders would usually fire on the same side ) , and ensured that " Raven " would have less dead - space to her front and rear . Carronades were not counted in a ship of the lines rated number of guns . The classification of Royal Navy vessels in this period can therefore mislead ; they would often be carrying fewer guns but 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 gun s , 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 trunnion s 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 . Gunnades , introduced around 1820 , should not be confused with the earliest carronades , which also featured trunnions . Range . As a result of irregularities in the size of cannonballs and the difficulty of boring out gun barrel s , 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 ) . Typical naval tactics in the late 18th century , however , emphasised short - range broadsides , so the range was not thought to be a problem . The carronade disappeared into history before the science of aerodynamics started . At the time there was no good theory to account for the range of cannon . We now know that the air resistance of the spherical cannonball in supersonic flight is much much greater than in subsonic flight . For a given weight of powder , a larger ball , having a large mass , would have a lower maximum velocity which would reduce the range of supersonic flight . But the increase in the distance of subsonic flight , as the air resistance is proportional to the square of the diameter but the mass is proportional to the cube , may have more than compensated . Carronades were short range because of their small gunpowder charge but their lower muzzle velocity required a higher trajectory . But at sea , the range of the long gun had little use . At sea , guns were on moving platforms making timing of fire , i . e . aim in the vertical plane , very difficult . Pitch and roll meant that most ships fought at close range of a few hundred yards or less . In battles between warships , carronades could be at a disadvantage , if they were fought outside its point blank range ; however , there is no evidence that any battle was decided outside of carronade range . Warships often aimed at the enemy ’ s hull to destroy its capacity for battle . A ball fired from a cannon , on the downward roll of the ship , would often ricochet off the sea into the enemy hull . A merchant ship would more often aim at the bigger target of the masts and rigging in the hope of escaping a pursuing enemy . The higher trajectory required for carronades , at ranges of 400 yards or more , was of little disadvantage for its use by merchant ships or any naval ship fleeing a more powerful enemy . Theory for centuries had always associated long barrels with long range but experience had also shown that shortening the barrel ( e . g . the English musket barrel between 1630 and 1660 went down from 4 to 3 feet long ) did not reduce performance as much as expected .