Seventy-four (ship)

The "seventy-four" was a type of two-decked sailing ship of the line, which nominally carried 74 guns. It was developed by the French navy in the 1740s, replacing earlier classes of 60- and 62-gun ships, as a larger complement to the recently developed 64-gun ships. Impressed with the performance of several captured French seventy-fours, the British Royal Navy quickly adopted similar designs, classing them as third rates. The type then spread to the Spanish, Dutch, Danish and Russian navies.

The design was considered a good balance between firepower and sailing qualities. Hundreds of seventy-fours were constructed, becoming the dominant form of ship-of-the-line. They remained the mainstay of most major fleets into the early 19th century. From the 1820s, they began to be replaced by larger two-decked ships mounting more guns. However, some seventy-fours remained in service until the late 19th century, when they were finally supplanted by ironclads.

Standardising on a common ship size was an appealing ideal for naval administrators and bureaucrats. Although the seventy-four was a common type, the ship classes were not identical, even within the same navy. In the period 1750–1790, seventy-fours could measure from just under 2,000 to 3,000 tons burthen. The armament could also vary considerably, with the lower deck mounting 24-pounder to 36-pounder long guns, and a variety of calibres (sometimes including a few carronades) used on the upper deck. Some seventy-fours of the Danish navy only carried 70 guns.