The Emerald class was a class of compositescrew corvettes designed by Nathaniel Barnaby for the Royal Navy. The ships were a development of the preceding Amethyst class that replaced wooden construction with one that combined frames and keels of wrought iron, a stem and stern post of cast iron and a cladding of teak. The additional longitudinal strength of the metal frames was designed to afford the opportunity to build in finer lines, and thus achieve higher speeds. The ships did not deliver this better performance, partly due to poor underwater design, and also were prone to oscillate in heavy weather.[1] In service, however, they proved to be good sailing vessels in all sorts of weather.[2][3] The ships were later redefined as third-class cruisers.[4]
The corvette had a length between perpendiculars of 220 ft (67 m), with a beam of 40 ft (12 m) and draught of 18 ft (5.5 m). Displacement was 2,120 long tons (2,150 t).[5] The engines were provided by Hawthorn.[6] The ship was equipped with six cylindrical boilers feeding a compound engine consisting of two cylinders, working on low and high pressure respectively, rated at 2,000 indicated horsepower (1,500 kW). The engines drove a single shaft, to give a design speed of 13.2 knots (24.4 km/h; 15.2 mph). In trials, the vessel achieved 12.28 knots (22.74 km/h; 14.13 mph) from 2,018 indicated horsepower (1,505 kW). Range for the class varied between 2,000 and 2,280 nautical miles (3,700 and 4,220 km; 2,300 and 2,620 mi) at 10 knots (19 km/h; 12 mph). The steam engine was complemented by 18,250 sq ft (1,695 m2) of sail, which was ship-rigged.[1] This proved difficult to handle as it meant the vessel was too responsive to weather.[3] Between 1880 and 1890, this was altered to a barque rig.[1]
Ruby had an armament consisting of 12 slide-mounted 64-pounderrifled muzzle-loading (RML) guns. Five were mounted to each side to provide a broadside, the remainder being fitted in pairs firing through embrasures at the ends of the ship. The ship had a complement of 232 officers and ratings.[1]
Ruby was commissioned to the East Indies Station. Amongst the crew was future Admiral of the FleetGeorge Callaghan.[10] The vessel was stationed at Trincomalee in Ceylon. On 28 November 1877, the corvette arrived at Port Blair, staying for two days before sailing on to Rangoon in Burma. The vessel returned on 23 February 1878, departing for Madras on 3 March.[11]Ruby carried one of only two batches of mail sent between Port Blair and Madras in the two years.[12] Shortly afterwards, the corvette was transferred to the Mediterranean. On 27 March, Ruby responded to a request from women and children in Macedonia suffering during the 1878 Macedonian rebellion.[13] On 30 May, the ship was deployed to Singapore to join the China Squadron.[14] The corvette subsequently returned to the Mediterranean and, by September, was supporting the British forces during a military expedition to Egypt.[15] On 24 October the warship left Alexandria and sailed to Malta.[16]
The corvette was the lead of the flotilla commanded by the future Admiral of the Fleet Charles Hotham.[20] The vessel subsequently returned to the UK. In December 1904, the ship was retired and turned into a coal hulk with the name C.10. During February 1921, the ship was sold to be broken up.[9]
Brassey, Thomas (2010) [1882]. "Tables of Ships: British and Foreign". The British Navy: Its Strength, Resources, and Administration. Cambridge: Cambridge University Press. pp. 549–605. ISBN978-1-10802-465-5.
Colledge, J.J.; Warlow, Ben (2006). Ships of the Royal Navy: The Complete Record of All Fighting Ships of the Royal Navy. London: Chatham Press. ISBN978-1-93514-907-1.
Winfield, R.; Lyon, D. (2004). The Sail and Steam Navy List: All the Ships of the Royal Navy 1815–1889. London: Chatham Publishing. ISBN978-1-86176-032-6. OCLC52620555.