HMS Iris (1877)

For other ships with the same name, see HMS Iris.

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.

A lithograph of Iris
History
United Kingdom
Name	Iris
Builder	Pembroke Dockyard
Laid down	10 November 1875
Launched	12 April 1877
Completed	April 1879
Fate	Sold for scrap, 11 July 1905
General characteristics (as built)
Class & type	Iris-class despatch vessel, later second-class cruiser
Displacement	3,730 long tons (3,790 t)
Length	331 ft 6 in (101 m)
Beam	46 ft (14 m)
Draught	20 ft 6 in (6.2 m)
Installed power	12 boilers; 6,000 ihp (4,500 kW)
Propulsion	2 × shafts; 2 × compound-expansion steam engines
Sail plan	Barque-rigged
Speed	17 knots (31 km/h; 20 mph)
Range	4,400 nmi (8,100 km; 5,100 mi) at 10 knots (19 km/h; 12 mph)
Complement	275
Armament	10 × 64 pdr rifled muzzle-loading (RML) guns

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 331 feet 6 inches (101 m), a beam of 46 feet (14 m), and a draught of 20 feet 6 inches (6.2 m). They displaced 3,730 long tons (3,790 t) at normal load^[1] and were the first British warships with an all-steel hull.^[2] Their crew consisted of 275 officers and ratings.^[1]

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.^[1] The engines were designed to produce a total of 6,000 indicated horsepower (4,500 kW) for a speed of 17 knots (31 km/h; 20 mph). Iris initially reached a maximum speed of 16.6 knots (30.7 km/h; 19.1 mph) from 7,086 ihp (5,284 kW) during her sea trials, but after new propellers were fitted, achieved 17.89 knots (33.13 km/h; 20.59 mph) from 7,330 ihp (5,470 kW).^[3] The ship carried enough coal to steam 4,400 nautical miles (8,100 km; 5,100 mi) at 10 knots (19 km/h; 12 mph). She was initially fitted with a barque sailing rig, but this was removed after a few years.^[1]

The Iris-class ships were originally armed with ten 64-pounder (6.3-inch (160 mm)) 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.^[1]

Construction and career

The War in Egypt, HMS Iris with the Gunboats Beacon and Decoy blockading Damietta, The Graphic 1882

Iris was laid down at the Pembroke Dockyard on 10 November 1875, launched on 12 April 1877 and completed in April 1879.^[1] She served with the Mediterranean Fleet from 1879 to 1887, then in the Portsmouth Reserve from 1887 to 1903. She was a tender to HMS St Vincent in 1903– 1904^[4] and was sold for scrap on 11 July 1905.^[1]