Engineering:Edgar-class cruiser

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Short description: Class of cruisers for the British Navy


HMSgib.jpg
HMS Gibraltar
Class overview
Name: Edgar class
Operators:  Royal Navy
Preceded by: Blake class
Succeeded by: Powerful class
Built: 1889–1894
In commission: 1893-1921
Completed: 9
Lost: 1
Scrapped: 8
General characteristics
Type: First class protected cruiser
Displacement: 7,700 tons
Length: 387 ft 6 in (118.11 m)
Beam: 60 ft (18.3 m)
Draught: 24 ft (7.3 m)
Propulsion: 2 shafts, 12,000hp
Speed: 20 knots (37 km/h) forced draught
Range: 10,000 nautical miles (19,000 km) at 10 knots (19 km/h)
Complement: 544
Armament:
  • 2 × BL 9.2-inch (230 mm) Mk VI guns
  • 10 × QF 6-inch (150 mm) guns
  • 12 × 6-pounder (57-mm) guns
  • 4 × torpedo tubes for 18-inch (450-mm) torpedoes[1]

The Edgar class were nine first-class protected cruisers built for the Royal Navy under the Naval Defence Act of 1889. The class gave long service and all of the ships participated in the First World War. One, HMS Hawke, was lost during the war, with the other eight being scrapped in the 1920s.

Design

Nine new first-class cruisers were required by the Naval Defence Act. Although the Blake-class cruisers were impressive ships and powerful, they were too large and expensive to simply repeat en masse.

The new ships were envisioned as reduced version of Blake and Blenheim, retaining the same main armament of two 9.2-inch BL guns and ten 6-inch QF guns. The 9.2-inch pieces were mounted singly on the centreline at either end of the upper deck, on turntable mountings provided with heavily-armoured open-backed gunshields which resembled turrets. The 6-inch battery was divided between two decks on each beam, with six upper deck guns (three on each beam) and four on the main deck, two to a beam. The main deck guns were in casemates, while the six upper deck guns were protected only by shields. For close-range defence against torpedo boats there were 12 QF 6-pounder Hotchkiss guns and four QF 3-pounder Hotchkiss guns. Armament was completed with four 18-inch torpedo tubes.

Displacement was reduced by 1,800 tons from Blake, length between perpendiculars by 15 feet. Propulsion came from steam expansion engines,[2] driving two shafts. With funnels as tall as the Blake class, the Edgars appeared stockier than the preceding ships. Despite this, slimming their beam by 5 feet, slightly reducing draught and providing highly reliable 12,000 ihp machinery (compared with the previous troublesome 13,000 ihp installation) meant the new ships would practically match their two larger predecessors' steaming performance.

The Edgar class' main armour protection was an internal protective deck, consisting of 5 in (130 mm) thick steel armour on the outboard slopes, which connected with the hull plating just below waterline level and rose up the further it extended into the ship, with 3 in (76 mm) on the flat of the deck over the magazines and machinery spaces. The gun casemates were 6 in (150 mm) thick, with 3 in (76 mm) shields for the 9.2-inch guns. The conning tower had 10 in (250 mm) armour. Four of the Edgar class were fitted with anti-torpedo bulge during refit in 1914.

Crescent and Royal Arthur were intended to operate as flagships for cruiser squadrons on foreign stations. They were built to a slightly modified design and are sometimes considered a separate class. In order to accommodate the additional flag officers and staff in the forward part of the ship, they had a forecastle one deck higher than their other sisters'. This additional weight forwards was balanced by the deletion of the forward 9.2-inch gun and its very heavy armoured gunshield, with sufficient weight allowance remaining afterwards for two additional 6-inch guns to be placed, sided, atop the forecastle in light open-backed shields.

Building programme

The following table gives the build details and purchase cost of the members of the Edgar class. Standard British practice at that time was for these costs to exclude armament and stores.

Right elevation, deck plan and hull section as depicted in Brassey's Naval Annual 1897
The bow of HMS Royal Arthur while drydocked in Sydney.
The stern of HMS Royal Arthur while drydocked in Sydney.
Ship Builder Maker
of
Engines
Construction Cost according to Brassey's Naval Annual
Laid down Launched Completed BNA 1895[3] BNA 1905[4] BNA 1906[5]
Edgar Devonport Dockyard Elder 3 Jun 1889 24 Nov 1890 2 Mar 1893 £401,083 £428,081 £410,980
Hawke Chatham Dockyard Elder 16 Jun 1889 11 Mar 1891 16 May 1893 £365,491 £413,101 £400,702
Endymion C & W Earle, Hull Earle 22 Nov 1889 22 July 1891 26 May 1894 £350,459 £397,973 £375,250
Royal Arthur
ex-Centaur
Portsmouth Dockyard Maudslay 20 Jan 1890 26 Feb 1891 2 Mar 1893 £402,414 £427,620 £412,033
Gibraltar Robert Napier & Sons, Govan Napier 2 Dec 1889 27 Apr 1892 1 Nov 1894 £347,634 £377,741 £373,236
Grafton Thames Ironworks Leamouth Humphrys 1 Jan 1890 30 Jan 1892 18 Oct 1894 £351,851 £381,958 £372,890
St George C & W Earle, Hull Maudslay 23 Apr 1890 23 Jun 1892 25 Oct 1894 £377,204 £407,540 £388,755
Theseus Thames Ironworks Leamouth Maudslay 16 Jul 1890 8 Sep 1892 14 Jan 1894 £347,577 £377,913 £370,359
Crescent Portsmouth Dockyard Penn 13 Oct 1890 30 Mar 1892 22 Feb 1894 £383,068 £411,108 £392,453


Notes

  1. Gardiner, Robert, ed (1979). Conway's All the World's Fighting Ships 1860–1905. Greenwich: Conway Maritime Press. pp. 66. ISBN 0-8317-0302-4. https://archive.org/details/conwaysallworlds0000unse_l2e2/page/66. 
  2. "H.M.S. Hawke". The Engineer: 229. 18 March 1892. http://www.gracesguide.co.uk/images/b/b4/Er18920318.pdf#page3. 
  3. Brassey's The Naval Annual 1895, p201-217
  4. Brassey's The Naval Annual 1905, p242-249
  5. Brassey's The Naval Annual 1906, p216-223

References

  • Brassey, Lord (ed) Brassey's The Naval Annual 1888-89
  • Brassey, T.A. (ed) Brassey's The Naval Annual 1890
  • Brassey, T.A. (ed) Brassey's The Naval Annual 1891
  • Brassey, T.A. (ed) Brassey's The Naval Annual 1892
  • Brassey, T.A. (ed) Brassey's The Naval Annual 1893
  • Brassey, T.A. (ed) Brassey's The Naval Annual 1894
  • Brassey, T.A. (ed) Brassey's The Naval Annual 1895
  • Brassey, T.A. (ed) Brassey's The Naval Annual 1896
  • Brassey, T.A. (ed) Brassey's The Naval Annual 1899
  • Brassey, T.A. (ed) Brassey's The Naval Annual 1902
  • Brassey, T.A. (ed) Brassey's The Naval Annual 1903
  • Brassey, T.A. (ed) Brassey's The Naval Annual 1904
  • Brassey, T.A. (ed) Brassey's The Naval Annual 1905
  • Leyland, J. and Brassey, T.A. (ed) The Naval Annual 1906
  • Gardiner, Robert, ed (1979). Conway's All the World's Fighting Ships 1860–1905. Greenwich: Conway Maritime Press. p. 440. ISBN 0-8317-0302-4. https://archive.org/details/conwaysallworlds0000unse_l2e2/page/440. 

External links