18-pounder long gun

18-pounder long gun
Firing of an 18-pounder. Engraving by Louis-Philippe Crépin.
Type	naval gun
Place of origin	France
Service history
Used by	France, Spain, Great Britain, Netherlands, Sweden, United States
Specifications
Weight	2.060 kg 365 kg (mount)
Barrel length	2.572 metres (18.544 calibres)
Calibre	138.7 mm

2.060 kg

The 18-pounder long gun was an intermediary calibre piece of artillery mounted on warships of the Age of sail. They were used as main guns on the most typical frigates of the early 19th century, on the second deck of third-rate ships of the line, and even on the third deck of late first-rate ships of the line.

As the 18-pounder calibre was consistent with both the French and the British calibre systems, it was used in many European navies between the 17th and the 19th century. It was a heavy calibre for early ships of the line, arming, for instance, the main batteries of Couronne in 1636. From the late 18th century, the French Navy used the 18-pounder in three capacities: as the main gun on frigates, as the battery on the upper gundeck of two-deckers, and lastly on the top deck of three-deckers.

French frigates began carrying the 18-pounder under Louis XV, when the two Pourvoyeuse class frigates, originally designed to carry 24-pounders, were equipped with it; at the time, a typical frigate would carry 12-pounders. Under Louis XVI, from 1779, the 18-pounder gradually became the standard calibre for frigates, starting with the Hébé Class. These frigates were built on standard patterns designed by Jacques-Noël Sané, carrying 26, and later 28 main guns, complemented with smaller pieces on the forecastle. Around 130 of these frigates were built. At the end of the Empire, 24-pounder frigates began supplanting the 18-pounder frigates. Frigates built after the Bourbon Restoration used a different artillery system, one involving 30-pounders.