Iris class cruiser

The Iris Class comprised two ships, HMS "Iris" and HMS "Mercury", which served with the Royal Navy. They were the Royal Navy's first all steel ships.

They were designed as dispatch vessels by William White under the direction of Nathaniel Barnaby but were later re-created as Second Class Cruisers. They were distinguished by their long, slender hulls which were influenced to an unprecedented degree by their machinery. This combination of fine lines and powerful twin Maudslay engines made them the fastest ships of their day, with "Mercury" attaining 18.6 knots from her 7,735 horsepower. This class re-established the traditional status of cruisers as being the eyes of the fleet - being faster than the contemporary ships of the line.

Despite being genuine steamers, the ships still sported a light barque sailing rig on completion, although this anachronism was gradually reduced and eventually removed. The ships were not armoured but extensive internal subdivision gave them some protection against flooding.

At 315ft (Mercury) 321ft (Iris) and with a beam of 46ft they displaced 3,730 tons fully loaded and carried 780 tons of coal. They were originally armed with 10 x 64 pounder MLRs and 4 torpedo carriages and converted in 1888 to 15 x 5 inch BL.

Both ships were built at the Pembroke Dockyard. "Iris" was launched in 1877 and sold in 1905 while "Mercury", launched a year later, was hulked at Chatham in 1914 and sold for scrap in 1919.

References

*Cruisers of the Royal and Commonwealth Navies by Douglas Morris. Maritime Books 1987. ISBN 0 907771 35 1.
*Archibald, E.H.H.; Ray Woodward (ill.) (1971). The Metal Fighting Ship in the Royal Navy 1860-1970. New York: Arco Publishing Co.. ISBN 0-6680-2509-3.