The Leander class was a four-ship cruiser programme ordered by the Admiralty in 1880. The class comprised , , , and .

Genesis "A new and better policy of unarmoured construction was inaugurated by the Admiralty of 1874-80. They began by building the two despatch vessels, and , with a speed not approached up to that date by any in naval service. In the Mercury and the Iris, the speed was obtained by an enormous development of horse-power… The cost per ton was equal to that of the most powerful ironclad, while the fighting power was inconsiderable."Lord Brassey, The Naval Annual, 1886, page 68

In 1880, the Admiralty Board were divided about next design of cruising ship to lay down. The First Naval Lord, Sir Astley Cooper Key, favoured an enlarged . Some of the other members of the board preferred an improved . The First Lord of the Admiralty, William H. Smith, backed the latter.Brown, Warrior to Dreadnought, Warship Development 1860–1905, page 111. A change of government occurred on 23 April 1880;The 1880 General Election took place from March to April 1880. Polling day was 5 April. The Liberals under William Ewart Gladstone gained a landslide victory. Gladstone took office on 23 April. The new Board of Admiralty were appointed on 12 May.See: Bartholomew Archive William Gladstone and the 1880 General Election Lord Northbook replaced W.H. Smith as First Lord, though Astley Cooper Key continued as First Naval Lord.See List of lords commissioners of the Admiralty#1861 to 1882 "Lord Northbook's board were deeply impressed with the necessity for developing the construction of vessel of the Leander" type. "The first four ships of a large class laid down for the protection of commerce under Lord Northbrook's board were of the Leander type. The Leanders have a displacement of 3,750 tons. Their speed is 17 knots… Their coal supply is 1016 tons. These ships were followed by the four ships of the Mersey type…"Lord Brassey, The Naval Annual, 1886, page 69

The Leanders were primarily designed for trade protection.Conway's All the World's Fighting Ships 1860–1905, page 61 In 1881, it was argued that Britain had fallen behind in cruisers to protect Britain's mercantile marine, which at the time was at least half the world total. "Taking 14 knots as the standard of high speed, we have only 11 swift cruisers, counting the Iris and Mercury despatch vessels among them. Fine vessels they are, and no doubt the and the , when they have got on board their new armament, will give a good account—a very good account indeed—of any cruiser in the world that is not an iron-clad. But the world is a large place; and eight or ten vessels cannot be everywhere, and the safety of our commerce imperatively demands that the swift cruisers which we have ready at the outbreak of a war shall be enough to clear the seas of privateers. Much use, as a war goes on, may, no doubt, be made of the armed merchantmen on the Admiralty List; but we must have Royal [Navy] cruisers to begin with, A commencement was made last year by the late Board in the Leander and her two consorts, which, with their partially protected machinery, their great speed, and their excellent guns, will be everything that can be desired for the purpose for which they were devised. The present Board have carried this policy farther. We are pushing on the Leanders, and we have laid down a fourth Leander at Pembroke, to occupy the spare time of the 200 extra men who are working on the iron-clads…"Hansard HC Deb 18 March 1881 vol 259 cc1389-90 Statement by the Secretary to the Admiralty, Mr George Trevelyan in the House of Commons, 18 March 1881.

On 2 December 1884, the Secretary to the Admiralty stated, "The present Board have been gradually developing, and, as I would venture to say, in an effective manner, our resources for the protection of commerce. The late Board of Admiralty laid down an admirable type for the purpose in the Leander class. We have followed in their footsteps by producing the Mersey type, and we now propose to go a step further in the same direction, by laying down vessels of the Mersey class, but protected by a belt in lieu of an armoured deck. The belt will, I think, be approved by my hon. Friend who sits behind me (Sir Edward J. Reed)."Hansard HC Deb 2 December 1884 vol 294 c455 House of Commons, the Secretary to the Admiralty, Sir Thomas Brassey. These belted cruisers were the .

Design

Compared with the Iris class, the designers of the Leander "cut down top hamper and took advantage of the recent advance in gun construction to reduce the weight of, while adding to the efficiency of armaments. The models approved for the new ships were favourable to high speed."

Armament "The armament consists of ten 6-inch breech-loading guns, two Gatling guns, ten Nordenfeld guns, four Gardner guns, and four tubes for launching Whitehead torpedoes. Four of the breech-loaders are fixed on revolving turntables which project beyond the sides of the ship. They are placed on either side of the upper deck at the fore end of the poop and after end of the forecastle. These bow guns can be trained from the cross fire of 4˚ forward to 45˚ abaft the beam, and the after guns from right aft fire to 45˚ before the beam. The remaining 6-inch breech-loading guns which these vessels carry are fitted at broadside ports in the ordinary way. The Nordenfeld guns are fitted in projecting parts of the topsides, and are so arranged as to give great training and great depression, firing into boats alongside. The Whitehead torpedoes are discharged from broadside ports on the lower deck, two forward and two aft.""Lord Brassey", The Naval Annual, 1886, page 199.

When Leander was first commissioned in May 1885, her armament was listed as: "Upper deck 10 6-in BL, 8 1-in Nordenfeld, 2 5-barrel and 2 2-barrel 0.45-in guns. 7-pdr and 9-pdr boats and field guns.2 second class torpedo boats. 4 torpedo dischargers"

Protection and watertight subdivision The Leanders relied for protection on subdivision, coal bunkers, and a one-and-a-half-inch (40 mm) armoured deck over 165 feet amidships. The armoured deck was just above the normal waterline at the centre, and sloped down at the sides to protect against shells entering at the waterline.

The 1886 edition of The Naval Annual described them as: "The Phaeton [sic] class differs from the Iris in having a protecting deck. The vessels are built of steel. The distinctive feature of the class is that they are unarmoured cruisers, having the magazines and machinery protected by a steel deck 1½ in. thick, and sloped at the sides in order to deflect any shot striking the vessel near the water line. When the coal bunkers are filled, these too will afford some protection, as they are ranged along the sides and across the ends of what has been called the vital part of the ship... Provision has of course been made by watertight bulkheads and numerous compartments for keeping the ship afloat if struck by shot or otherwise injured in the hull. The Leander struck the Hornet Rock shortly after she was commissioned. The sea entered through numerous rivet holes where rivets had been sheared, but the compartment kept the ship afloat in a working condition."

Propulsion "With regard to their steaming capabilities, it may be noted that these cruisers with an authorized complement of coal of 725 tons have room in their bunkers for 1000 tons.On page 69 of The Naval Annual, 1886, it says: "Their coal supply is 1016 tons." They also carry three masts, but are not expected to have much sailing power."

"The Phaëton has been tried in the Solent. At the previous six-hour' full power trial of the Phaëton there was a difficulty experienced in maintaining steam from want of draught in the stokeholds. (Only the Leander of this class has been fitted with fans for forced draught.) The funnels were afterwards raised from to (the same height as those of the first-class cruisers), while the space between the firebars was increased. The effect of these changes at the trial was very marked, the engines being provided with an abundance of steam without their being any necessity for resorting to the blast. The trial was intended to have been for six hours, but during the eleventh half-hour, the expansion gear of the starboard engine heated and snapped, and the run was brought to a premature close. As, however the machinery worked without any hitch of any kind, and was developing power largely in excess of the Admiralty contract, it was agreed by the officers superintending the trial to accept the means of the five hours as a sufficient test of performance. These afforded the following data: Steam in the boilers, 85.35 lbs [588.5 kPa]; vacuum, starboard and port; revolutions, 100; mean pressures, starboard, 43.7 and 11 lb. [301 kPa and 76 kPa] and 43 and 11.7 lb. [300 kPa and 81 kPa] port; collective horsepower, or nearly 600 horses [450 kW] beyond the contract. The mean speed registered by runs on the measured mile was , which was remarkable, notwithstanding her light draught. The coal consumption did not exceed 2.39 lbs. per unit of power per hour [1.45 kg coal per hour per kiloWatt]."Lord Brassey, The Naval Annual, 1886, pages 199-200.

Name Indicated Horse Power (IHP)Lord Brassey, The Naval Annual, 1887, pages 192. Note that Brassey quotes data in Imperial units. French "System International" equivalents have been calculated from them for Wikipedia. Weight of Engines per IHP Weight of Boilers (including water) per IHP Total Weight of Machinery per IHP lb/IHP kg/kW lb/IHP kg/kW lb/IHP kg/kW Iris 136 83 173 105 309 188 Leander 139 85 196 119 335 204 Mersey 50 104 63 186½ 113

Establishment of ship's company When the Leander first commissioned her establishment of ship's company was listed as follows in her log. (Note the way that the engine room establishment officers are not listed with the officers.) Type Number Officers 18 Petty officers 41 Seamen and other ratings 100 Boys 13 Marines 36 Engine-room establishment officers 4 P.O. and stokers 63 Total 275 Source: Log of HMS Leander 29 May 1885 – 22 May 1886.Log of HMS Leander 29 May 1885 – 22 May 1886, UK National Archives file ADM 53/14282 The order is as listed in the original.

In the 1888 British annual naval manoeuvres, "the proportion of untrained (2nd Class) stokers which were draughted to several of the ships appears to have been too large."The Naval Annual, 1888-89 – supplementary report of the committee on the naval manoeuvres, pages 439. The opinion of the captain of the Arethusa was that the "engine room complement [was] insufficient by 2 engine room artificers, 2 leading stokers, and 23 stokers."The Naval Annual, 1888-89 – supplementary report of the committee on the naval manoeuvres, pages 440.

The Navy List gave the following composition of officers for the Leander in December 1885 (order as in the original):Navy List December 1885, page 216 1 Captain 5 Lieutenants 1 Staff Surgeon 1 Staff Paymaster 1 Staff Engineer 1 Sub-Lieutenant 1 Assistant Paymaster 1 Engineer 2 Assistant Engineers 2 Gunners 4 Boatswains 1 Carpenter Total 21 (including 4 engineers).

Building programme