HMS Iris the lead ship of her class of two ships built for the Royal Navy in the 1870s. They were the first all-steel warships to serve with the Royal Navy.
The Iris-class ships were designed as dispatch vessels and were later redesignated as second-class protected cruisers. Iris had an overall length of 331feet, a beam of 46feet, and a draught of 20feet. They displaced 3730LT at normal load and were the first British warships with an all-steel hull.[1] Their crew consisted of 275 officers and ratings.[2]
The Iris class was powered by a pair of horizontal four-cylinder Maudslay, Sons and Field compound-expansion steam engines, each driving one propeller shaft using steam from eight oval and four cylindrical boilers.[2] The engines were designed to produce a total of 6000ihp for a speed of 17kn. Iris initially reached a maximum speed of from 7086ihp during her sea trials, but after new propellers were fitted, achieved from .[3] The ship carried enough coal to steam 4400nmi at . She was initially fitted with a barque sailing rig, but this was removed after a few years.[2]
The Iris-class ships were originally armed with ten 64-pounder (6.3inches) rifled muzzle-loading (RML) guns, eight on the main deck and the remaining pair on the upper deck on pivot mounts to serve as chase guns fore and aft.[2]
Iris was laid down at the Pembroke Dockyard on 10 November 1875, launched on 12 April 1877 and completed in April 1879.[2] She served with the Mediterranean Fleet from 1879 to 1887, then in the Portsmouth Reserve from 1887 to 1903. She was a tender to in 1903– 1904[4] and was sold for scrap on 11 July 1905.[2]