M15-class Monitor

The ''M15'' class comprised fourteen monitors of the Royal Navy, all built and launched during 1915.

Design

The ships of this class were ordered in March, 1915, as part of the Emergency War Programme of ship construction. They were designed to use the 9.2 inch Mk VI gun turrets removed from the and the Mk X turrets held in stock for the and s. This resulted in the first four of the class, which were built by William Gray & Company of Hartlepool, receiving the Mk X mounting. The remaining ten ships, all built by Sir Raylton Dixon & Co., Middlesbrough, all received the Mk VI mounting.

During September 1915, the 9.2 inch guns of HMS ''M24'', ''M25'', ''M26'' and ''M27'' were removed for use as artillery. These were replaced by 7.5-inch guns. ''M24'' and ''M25'' received the spare guns reserved for the recently sunk pre-dreadnought battleship , ''M26'' received one of ''Swiftsure''s spare guns. ''M27'' received 6-inch (M27) guns.

''M21'' and ''M23'' also had their 9.2-inch gun removed in 1917, receiving 7.5-inch guns from the decommissioned pre-dreadnought .

The class used a mixture of propulsion methods. ''M21'' and '' M22'' were fitted with conventional triple-expansion steam engines, ''M24'' was fitted with four-cylinder paraffin engines, and the remainder received Bolinder four-cylinder semi-diesel engines.

Admiral Reginald Bacon, who had commanded several of the M15 class in the Dover Patrol, wrote about his experiences with the ships of the patrol in 1919. While generally positive about the performance of the design, he noted that they had a tendency to roll, using a specific occasion with ''M25'' as an example;
:"The ''M25'', while in the mouth of the Thames at anchor, rolled 180 degrees in ten seconds - that is, she made two complete rolls of 45 degrees each way, each occupying only five seconds."

Service

''M25'', ''M26'', ''M27'' and ''M28'' served in the Dover Patrol from 1915 to 1918. The remainder served in the Mediterranean from 1915, with ''M23'' joining the Dover Patrol in June 1917 and ''M21'' in October 1917.

As part of the intervention into the Russian civil war ''M23'', ''M24'', ''M25'' and ''M27'' served in support of British and White Russian forces in the White Sea in May to September 1919.

''M22'' was converted to a minelayer in 1920, whilst ''M23'' became a drill ship, surviving until 1959.

Ships of the class

*''M15'' - launched on 28 April 1915 and sunk by on 11 November 1917.
*''M16'' - launched on 3 May 1915 and sold 29 January 1920.
*'' M17'' - launched on 12 May 1915 and sold 12 May 1920.
*'' M18'' - launched on 15 May 1915 and sold 29 January 1920.
*'' M19'' - launched on 4 May 1915 and sold 12 May 1920.
*'' M20'' - launched on 11 May 1915 and sold 29 January 1920.
*'' M21'' - launched on 27 May 1915 and mined 20 October 1918.
*'' M22'' - launched on 10 June 1915, renamed ''Medea'' 1925 and sold December 1938
*'' M23'' - launched on 17 June 1915, renamed ''Claverhouse'' 1922 and sold 1959
*''M24'' - launched on 9 August 1915 and sold 29 January 1920.
*'' M25'' - launched on 24 July 1915 and scuttled 16 September 1919
*'' M26'' - launched on 24 August 1915 and sold 29 January 1920.
*'' M27'' - launched on 8 September 1915 and scuttled 16 September 1919
*'' M28'' - launched on 28 June 1915 and sunk during the Battle of Imbros 20 January 1918

References

Bibliography

* &nbs
Vol. 1
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Vol. 2
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*Dittmar, F. J. & Colledge, J. J., "British Warships 1914-1919", (Ian Allan, London, 1972),
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*Gray, Randal (ed), "Conway's All the World's Fighting Ships 1906–1921", (Conway Maritime Press, London, 1985),
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External links

{{DEFAULTSORT:M15 Class Monitor
Monitor classes