Fifth-rate

In Britain's Royal Navy during the classic age of fighting sail, a fifth rate was the penultimate class of warships in a hierarchical system of six "ratings" based on size and firepower.

The rating system in the British (originally English) Royal Navy as originally devised had just four rates, but early in the reign of Charles I the original fourth rate (derived from the "Small Ships" category under his father, James I) was divided into new classifications of fourth, fifth, and sixth rates. While a fourth rate was defined as a ship of the line, fifth and the smaller sixth-rates were never included among ships-of-the-line. Nevertheless, during the Anglo-Dutch Wars of the 17th century, fifth rates often found themselves involved among the battle fleet in major actions. Structurally, these were two-deckers with a complete battery on the lower deck, and fewer guns on the upper deck (below the forecastle and quarter decks, usually with no guns in the waist on this deck).

The fifth rates at the start of the 18th century were small two-deckers, generally either 40-gun ships with a full battery on two decks, or "demi-batterie" ships, carrying a few heavy guns on their lower deck (which often used the rest of the lower deck for row ports) and a full battery of lesser guns on the upper deck. However, the latter were gradually phased out, as the low freeboard (the height of the lower deck gunport sills above the waterline) meant that it was often impossible to open the lower deck gunports in rough weather. The 40-gun (or later 44-gun) fifth rates continued to be built until the later half of the 18th century (a large group were built during the American War of Independence). From mid-century, a new fifth-rate type was introduced: the classic frigate, with no gun ports on the lower deck, and the main battery of from 26 to 30 guns disposed solely on the upper deck, although smaller guns were mounted on the quarterdeck and forecastle.

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