HMS ''Mercury'' was one of two
despatch vessels, later redesignated as second class
cruiser
A cruiser is a type of warship. Modern cruisers are generally the largest ships in a fleet after aircraft carriers and amphibious assault ships, and can usually perform several roles.
The term "cruiser", which has been in use for several hu ...
built for the
Royal Navy
The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against F ...
during the 1870s. The two ships were the first all-steel warships in the Royal Navy.
Design and description
The ''Iris''-class ships were designed as
dispatch vessels and were later redesignated as second-class
protected cruiser
Protected cruisers, a type of naval cruiser of the late-19th century, gained their description because an armoured deck offered protection for vital machine-spaces from fragments caused by shells exploding above them. Protected cruisers re ...
s. ''Mercury'' had an
overall length
The overall length (OAL) of an ammunition cartridge is a measurement from the base of the brass shell casing to the tip of the bullet, seated into the brass casing. Cartridge overall length, or "COL", is important to safe functioning of reloads i ...
of , a
beam
Beam may refer to:
Streams of particles or energy
*Light beam, or beam of light, a directional projection of light energy
**Laser beam
*Particle beam, a stream of charged or neutral particles
**Charged particle beam, a spatially localized grou ...
of , and a
draught of . The ships
displaced at normal load
[ and were the first British warships with an all-steel hull. Their crew consisted of 275 officers and ratings.][Lyon & Winfield, p. 270]
The ''Iris'' class was powered by a pair of horizontal four-cylinder Maudslay, Sons and Field
Maudslay, Sons and Field was an engineering company based in Lambeth, London.
History
The company was founded by Henry Maudslay as Henry Maudslay and Company in 1798 and was later reorganised into Maudslay, Sons and Field in 1833 after his sons ...
compound-expansion steam engines, each driving one propeller shaft
A drive shaft, driveshaft, driving shaft, tailshaft (Australian English), propeller shaft (prop shaft), or Cardan shaft (after Girolamo Cardano) is a component for transmitting mechanical power and torque and rotation, usually used to connect ...
using steam from eight oval and four cylindrical boilers.[ The engines were designed to produce a total of for a speed of . ''Mercury'' reached a maximum speed of from , making her the fastest warship in the world.][Roberts, p. 74] The ship carried enough coal to steam at .[ Originally equipped with a light ]barque
A barque, barc, or bark is a type of sailing ship, sailing vessel with three or more mast (sailing), masts having the fore- and mainmasts Square rig, rigged square and only the mizzen (the aftmost mast) Fore-and-aft rig, rigged fore and aft. Som ...
rig, her sails were soon removed and the class became the first "mastless cruisers".[Archibald, p. 43]
The ''Iris''-class ships were originally armed with ten 64-pounder () rifled muzzle-loading ( RML) guns, eight on the main deck
The main deck of a ship is the uppermost complete deck extending from bow to stern. A steel ship's hull may be considered a structural beam with the main deck forming the upper flange of a box girder and the keel forming the lower strength memb ...
and the remaining pair on the upper deck on pivot mount
A pivot gun was a type of cannon mounted on a fixed central emplacement which permitted it to be moved through a wide horizontal arc. They were a common weapon aboard ships and in land fortifications for several centuries but became obsolete aft ...
s to serve as chase gun
A chase gun (or chaser), usually distinguished as bow chaser and stern chaser, was a cannon mounted in the bow (aiming forward) or stern (aiming backward) of a sailing ship. They were used to attempt to slow down an enemy ship either chasing ( ...
s fore and aft.[
]
Construction and career
''Mercury'' was laid down
Laying the keel or laying down is the formal recognition of the start of a ship's construction. It is often marked with a ceremony attended by dignitaries from the shipbuilding company and the ultimate owners of the ship.
Keel laying is one o ...
at Pembroke Dockyard
Pembroke Dockyard, originally called Pater Yard, is a former Royal Navy Dockyard in Pembroke Dock, Pembrokeshire, Wales.
History
It was founded in 1814, although not formally authorized until the Prince Regent signed the necessary Order in Cou ...
on 16 March 1876, launched on 17 April 1878 and completed in September 1879.[
''Mercury'' served with the Portsmouth Reserve from 1879 to 1890, in China from 1890 to 1895 and with the Portsmouth Reserve again from 1895 to 1903. She served as a navigation school ship for navigating officers from 1903 to 1905 and a submarine depot ship at Portsmouth from 1906 to 1913, and at ]Harwich
Harwich is a town in Essex, England, and one of the Haven ports on the North Sea coast. It is in the Tendring district. Nearby places include Felixstowe to the north-east, Ipswich to the north-west, Colchester to the south-west and Clacton-on- ...
in 1913.[Warlow, p. 93] There were plans to rename her ''Columbine'' in 1912, but these were rescinded and instead she was hulked at Rosyth
Rosyth ( gd, Ros Fhìobh, "headland of Fife") is a town on the Firth of Forth, south of the centre of Dunfermline. According to the census of 2011, the town has a population of 13,440.
The new town was founded as a Garden city-style suburb ...
in 1914 with the port depot ship there, HMS ''Columbine'', the former . She was moved to Chatham, where she became an accommodation ship from 7 January 1918, and was paid off in March 1919.Bo'ness
Borrowstounness (commonly known as Bo'ness ( )) is a town and former burgh and seaport on the south bank of the Firth of Forth in the Central Lowlands of Scotland. Historically part of the county of West Lothian, it is a place within the Falki ...
, on 9 July 1919.
Notes
Bibliography
*
*
*
*
* Morris, Douglas (1987). ''Cruisers of the Royal and Commonwealth Navies''. Liskeard: Maritime Books. .
* *
{{DEFAULTSORT:Mercury
Iris-class cruisers
Ships built in Pembroke Dock
1878 ships