HMS Racer
Class overview
Name	Mariner-class gunvessels (later reclassified sloops)
Builders	Devonport Dockyard Malta Dockyard Milford Haven Shipbuilding Co
Operators	Royal Navy
Cost	Hull: £34,834 Machinery: £12,787 (Reindeer)
Built	1883–1888[1]
In commission	1883–1929
Completed	6
General characteristics
Type	Composite screw gunvessel (rated as sloops from 1884)
Displacement	970 tons
Length	167 ft (51 m) pp
Beam	32 ft (9.8 m)
Draught	14 ft (4.3 m)[2]
Installed power	850 ihp (630 kW)
Propulsion	2-cylinder horizontal compound-expansion steam engine Single screw[2]
Sail plan	Barque-rigged, except Icarus (barquentine-rigged)
Speed	11+1⁄2 knots (21.3 km/h)
Range	Approximately 2,100 nmi (3,900 km) at 10 kn (19 km/h)[2]
Complement	126
Armament	8 × 5-inch 38cwt breech-loading guns[Note 1] 1 × light gun 8 × machine guns[2]

The Mariner class was a class of six 8-gun gunvessels (sloops from 1884) built for the Royal Navy between 1883 and 1888. Four were built in the Naval Dockard at Devonport, and two elsewhere; the Acorn was built by contract at Jacobs Pill on the Pembroke River (a private yard founded in the 1870s by Sir Edward Reed), while the Melita was built in the Malta Dockyard, the only substantial ship of the Royal Navy ever to be built in the island.

Designed by Nathaniel Barnaby,^[2] the Royal Navy Director of Naval Construction, the hull was of composite construction; that is, iron keel, frames, stem and stern posts with wooden planking. The entire class were re-classified in November 1884 as sloops before they entered service.

Propulsion was provided by a 2-cylinder horizontal compound-expansion steam engine of 850 indicated horsepower (634 kW) driving a single screw. This arrangement provided enough power to drive the ships at 11+1⁄2 knots (21.3 km/h), although Icarus and Melita recorded 12.5 knots.^[2]

All the ships of the class were built as barque-rigged vessels, except Icarus, which had no main yards provided, making her a barquentine.

The class was designed and built to carry eight 5-inch 38cwt breech-loading guns,^{[Note 2]} one light gun and eight machine guns.^[2] Melita had 40cwt guns instead of 38cwt, and Reindeer had two of her guns removed.^[2]

All the ships were laid down in 1882-83. While most of the ships were completed relatively quickly, Melita took six years to build. The intention behind building her at Malta was to make use of the substantial workforce at Malta Dockyard who were otherwise (it was felt) unemployed when the Mediterranean Fleet was away. The experiment cost £10,000 more than the British-built versions, and incurred substantial delay; it was not repeated, and Melita remained the only warship of any significant size ever built in Malta for the Royal Navy.^[3]

Media related to Mariner class gunvessel at Wikimedia Commons

• Colledge, J. J.; Warlow, Ben (2006) [1969]. Ships of the Royal Navy: The Complete Record of all Fighting Ships of the Royal Navy (Rev. ed.). London: Chatham Publishing. ISBN 978-1-86176-281-8.
• Preston, Antony; Major, John (2007). Send a Gunboat: The Victorian Navy and Supremacy at Sea, 1854–1904 (2nd ed.). London: Conway. ISBN 978-0-85177-923-2.
• Winfield, R.; Lyon, D. (2004). The Sail and Steam Navy List: All the Ships of the Royal Navy 1815–1889. London: Chatham Publishing. ISBN 978-1-86176-032-6. OCLC 52620555.