The Carron Company, known in the beginning as, “Roebucks, Garbett and Cadells”, entered the world of ordnance manufacture in November 1761, when they cast a 6-pounder gun. The company had only been founded less than two years previously and had no real knowledge of this new venture. Only one month before that first gun had been produced, the resident managing partner, William Cadell junior, had made a special visit to Edinburgh Castle, where he supposedly took measurements and patterns of some of the guns there. At Carron, the challenge of commencing a new business, in which none of the partners had previously been involved, and where most of the workforce and building materials had been brought from England, should have been enough to occupy the thoughts of these early pioneers, without entering into a specialised field. Their motive was the financial returns from the most lucrative product then to be made in iron; the learning process would be longer than they envisaged.
In early 1762, they made an offer to the Board of Ordnance to supply them with guns of various calibres, trucks (gun carriages) and shot, but only the latter was acceptable to the Board. In those days, the Board of Ordnance was an all-powerful government agency, responsible for the purchase and testing (proofing) of guns and other items of armaments. However, in 1764, the company was awarded a contract to supply guns to the Board, thought to have been due to the influence of new Carron partner, John Adam. Over the next few years, the quality of the guns supplied by Carron was erratic, having a higher rejection and failure rate that those produced elsewhere. The manager was aware of the shortcomings, but does not seem to have had the support of his fellow partners. The matter drew to a head in 1773 after the Board of Ordnance’s brassfounder, Verbruggan, found that the Carron guns were made from badly refined metal. Carron Company lost their contract and guns supplied by them were then systematically removed from the ships of the navy. Cadell’s successor, Charles Gascoigne, had tried to resolve the problem since he had taken over the post in 1769. In 1771, John Smeaton, who acted as Carron Company’s technical advisor, had been drafted in, and his new cylinder and gun boring mills were erected within the Works. The new gun boring mill does not appear to have been the answer. A new assay furnace was built in 1774, which suggests that they were becoming more aware of the need to improve their iron. Until that time, it had been the practice to cast the guns around a central newel (a pole covered with clay, resembling a gun barrel) and then bore them. It was discovered that guns cast solid and then bored, gave a better result. This then, became the favoured method.
In about 1775, John Wilkinson, the celebrated English ironfounder, invented a new cannon boring machine, where the casting sat in a horizontal position and turned, whilst the boring bit or cutter advanced into it. John Smeaton apparently showed those at Carron, the principle of this machine, which was then adopted. All guns at Carron Works were then cast solid and then accurately bored out on this new machine. The new accuracy in boring led to the reduction in windage, i.e. the gap left between the sides of the gun barrel and the face of the shot. A larger windage had until then been required (because of the inaccuracy of boring) to prevent the shot jamming in the gun barrel; but a certain amount of energy was always lost because of this. The reduction in windage resulted in less powder being required for the charge and hence less metal used in the gun itself. Carron’s first gun made as such in 1776, was known as the ‘Light New Constructed Gun’.
Two years later, a new type of gun, which was small and light but had a large bore, made its appearance. Because of its size and the damage it could cause with its larger shot, it became popular with merchant ships and then with the Navy. It was given the name ‘carronade’. The gun’s inventor is now generally believed to have been Lt. Gen. Melville. The carronade was developed and improved over a period of about 20 years; its fame probably culminating with the end of the Napoleonic War. During the initial assault in the Battle of Trafalgar in 1805, one of the two 68-pounder carronades mounted on HMS Victory’s forecastle, was used to deadly effect against the French flagship Buccentaure. In 1796, Carron Company was asked to manufacture long guns for the Board of Ordnance. These were the Government Pattern Guns invented by Thomas Blomefield in the 1780s and now familiarly on display at Edinburgh and Stirling Castles, and at the clocktower of old Carron Works. Guns ceased to be made at Carron by the 1850s.
The pictures above show three of the guns on display at the works at present. On the left is a 12-pounder carronade manufactured in 1803 and on the right two 9-pounder Government Pattern or Blomefield guns from 1797.
Brian Watters (2005)