A 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 and its main function was to serve as a powerful, short-range, anti-ship and anti-crew weapon. The carronade was designed as a naval weapon with a low muzzle velocity for merchant ships. It was produced by the Carron ironworks and was at first sold as a system with the gun, mounting, 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 that the shot weighed the same as the roundshot, while some other canister and grapeshot were also included which weighed one and a half times the roundshot. Its invention is variously ascribed to Lieutenant General Robert Melville in 1759, or to Charles Gascoigne, in its early years, the weapon was sometimes called a mellvinade or a gasconade. The carronade can be seen as the culmination of a development of naval guns reducing the barrel length, the advantages for merchant ships are described in an advertising pamphlet of 1779. Production of both shot and gun by the 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, the reduced recoil did not alter the alignment of the gun. The smaller gunpowder charge reduced the heating in action. The pamphlet advocated the use of cartridges, which eliminated the need for wadding and worming. Simplifying gunnery for comparatively untrained merchant seamen in both aiming 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 enemy, a carronade weighed a quarter as much and used a quarter to a third of the gunpowder charge as a long gun firing the same cannonball. The reduced charge allowed carronades to have a length and much lighter weight than long guns. Increasing the size of the bore and ball reduces the length of barrel. Long guns were also heavy in comparison to carronades because they were over-specified, being capable of being double-shotted. Carronades also required a smaller gun crew, which was important for merchant ships. 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 privateers
68-pounder British naval carronade, with slider carriage, on HMS ''Victory''
Diagram of a carronade mounting. The lack of a nozzle or muzzle cup suggests this carronade pre-dates ca. 1790, and it must date to 1785 or earlier as a copy of this drawing in the Dutch archives bears that date.