NAVYPEDIA

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Colossus

Ships

Name	No	Yard No	Builder	Laid down	Launched	Comp	Fate
Colossus			Portsmouth DYd	6.6.1879	21.3.1882	31.10.1885	gunnery school 1904
Edinburgh (ex-Majestic)		205	Pembroke DYd	29.3.1879	18.3.1882	8.7.1887	tender 1899 - 1905, target 1908

Technical data

Displacement normal, t	9420
Displacement full, t
Length, m	99.1 pp
Breadth, m	20.7
Draught, m	7.85
No of shafts	2
Machinery	2 3-cyl IVC, 10 eliptical boilers
Power, h. p.	Colossus: 7488 Edinburgh: 6808
Max speed, kts	Colossus: 16.5 Edinburgh: 16
Fuel, t	coal 970
Endurance, nm(kts)	6200(10)
Armour, mm	compound; citadel: 457 - 356 sides with 559mm wood backing, 406 - 330 bulkheads, turrets: 406 - 356, decks: 76 - 64, CT: 356
Armament	Colossus: 2 x 2 - 305/25 BL Mk II/III, 5 x 1 - 152/26 BL Mk IV/VI, 6 x 1 - 57/43 6pdr Nordenfelt Mk I, 2 - 356 TT (beam) Edinburgh: 2 x 2 - 305/25 BL Mk IV, 5 x 1 - 152/26 BL Mk IV/VI, 7 x 1 - 57/43 6pdr Nordenfelt Mk I, 2 - 356 TT (beam)
Complement	396

Graphics

Project history

Built under the 1878-79 Estimates, Colossus and Edinburgh were basically enlarged versions of the Ajax class with a slightly higher speed, a heavier secondary armament, increased endurance and improved handling and sea-keeping qualities. However, they incorporated several innovations which marked them as a major advance over the earlier design: breech loaded guns, compound armour for hull and the use of steel instead of iron for the majority of the hull structure.

The CT gave good all-round vision, being placed fwd of mainmast with the charthouse on its roof. The stability level was even higher than in the earlier citadel ships and anti-rolling tanks and deep bilge keels were provided, but they had a long, fast roll making them bad gun platforms in a seaway. They were difficult to handle and manoeuvre but were better in this respect than the Ajax class.

Ships were originally designed to carry the same main armament as the Ajax but this was altered to 305mm BLs while they were under construction. They were the first ships to have a secondary armament of any significance, with 1 152mm gun on each side of the fwd superstructure and 1 152mm on each side and 1 at aft end of the aft superstructure.

Both ships ran trials in 1883-1884, but completion was delayed because of the late delivery of the armament.

Edinburgh was laid down as Majestic and renamed before launch 16.3.1882.

Ship protection

The citadel was similar to that in Ajax but was larger and of oval shape with semi-circular end bulkheads to deflect projectiles. It was 37.5m long and 4.9m deep, the outer thickness of armour being compound. The area fore and aft of the citadel, above the protective deck, was extensively sub-divided, the compartments at the ships`sides being cork-filled and bounded by cofferdams, while the inner compartments were employed as coal bunkers.

Modernizations

1898, Colossus: - 5 x 1 - 152/26, 6 x 1 - 57/43; + 5 x 1 - 152/27 QFC Mk I/IV / I/VI / II/IV / II/VI / III/IV / III/VI, 4 x 1 - 57/40 6pdr Hotchkiss Mk I, 10 x 1 - 47/40 3pdr Hotchkiss Mk I

1898, Edinburgh: - 5 x 1 - 152/26, 7 x 1 - 57/43; + 5 x 1 - 152/27 QFC Mk I/IV / I/VI / II/IV / II/VI / III/IV / III/VI, 4 x 1 - 57/40 6pdr Hotchkiss Mk I, 10 x 1 - 47/40 3pdr Hotchkiss Mk I

Naval service

Colossus in 1893 became a coastguard ship at Holyhead. She was placed in reserve in 1901, and in 1904 became a tender to Excellent. She was put up for sale in September 1906 but not towed away until 6.10.1908. Edinburgh served as coastguard ship at Hull and Queensferry in 1894-1897. She was in reserve in 1897-1899, used as tender to Wildfire at Sheerness in 1899-1905, served in Special Reserve at Chatham in 1906 and was finally employed as target ship for experiments with shell and armour plate in 1908, wreck was sold to BU 11.10.1910.

Thanks to Wolfgang Stöhr for additional information on this page.