HMS Iris (1877)
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.
Design and description
The Iris-class ships were designed as dispatch vessels and were later redesignated as second-class protected cruisers. Iris had an overall length of, a beam of, and a draught of. They displaced at normal load and were the first British warships with an all-steel hull. Their crew consisted of 275 officers and ratings.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. The engines were designed to produce a total of for a speed of. Iris initially reached a maximum speed of from during her sea trials, but after new propellers were fitted, achieved from. The ship carried enough coal to steam at. She was initially fitted with a barque sailing rig, but this was removed after a few years.
The Iris-class ships were originally armed with ten 64-pounder rifled muzzle-loading 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.