Osprey-class sloop explained

The Osprey class was a Royal Navy class of screw-driven sloops built between 1874 and 1877. Nine additional ships were built to a revised design, the . They were the first class of ship in the Royal Navy to use glass scuttles.

Design

They were of composite construction, with wooden hulls over an iron frame. Five ships of the class were built, which had been designed in 1874 by the Royal Navy's Chief Constructor, William Henry White. They were the first ships in the Royal Navy to have glass scuttles instead of solid plug scuttles.

Propulsion

The original design, as fitted to the first two ships of the class, was a single-expansion returning-rod steam engine, but the power was insufficient, and they failed to meet the contracted speed. Wild Swan and Penguin were re-engined after their first commission to match the better engines in the rest of the class. In the final installation, power was provided by three cylindrical boilers, which supplied steam at to a two-cylinder horizontal compound-expansion steam engine driving a single 13inchesft1inchesin (ftin) screw. The power varied wildly from ship to ship, with Penguin generating only 666ihp and Pelican managing nearly twice as much, at 1056ihp. Because of this, top speeds ranged between 10 and 12 knots.[1]

Armament

They were armed with two 7-inch (90cwt) muzzle-loading rifled guns on pivoting mounts, and four 64-pounder muzzle-loading rifled guns (two on pivoting mounts, and two broadside). Four machine guns and one light gun completed the weaponry. Wild Swan and Pelican later had the muzzle-loading guns replaced with two 6-inch (81cwt) breech-loaders and six 5-inch (31cwt) breech-loaders.

Sail plan

All the ships of the class were provided with a barque rig, that is, square-rigged foremast and mainmast, and fore-and-aft sails only on the mizzen mast.

Crew

They had a complement of approximately 140 men.

Development

The design was revised in 1877 and nine ships were ordered to a modified version, the . Identical in many respects, the Doterels lacked the graceful clipper bow of the Ospreys, although they benefited from more power.

Ships

NameShip BuilderLaid downLaunchedCommissionedFate
Wild SwanRobert Napier and Sons, Govan14 September 187428 January 187623 August 1877Renamed Clyde in 1904 as the Royal Naval Reserve drill ship at Aberdeen. Renamed Columbine in 1912. Sold for breaking up 4 May 1920
PenguinRobert Napier and Sons14 July 187425 March 187623 August 1877Sold as a crane hulk 1924, burnt out 13 December 1960
OspreySheerness Dockyard18755 August 187619 April 1877Sold for breaking 29 April 1890
PelicanDevonport Dockyard8 March 187526 April 187729 November 1877Sold as a supply ship 22 January 1901
CormorantChatham Dockyard187512 September 18772 July 1878Harbour hulk November 1889, renamed Rooke July 1946. Scrapped at Málaga in 1949

Bibliography

Notes and References

  1. The lower power figures may be the trials figures from the initial installation in Wild Swan and Pelican and should be treated with caution.