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 utilise the 9.2 inch Mk VI gun turrets removed from the "Edgar" Class and the Mk X turrets held in stock for the "Drake" class and "Cressy" class cruisers. This resulted in the first four of the class, which were built by William Gray and 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 (M24 to M26) and 6 inch (M27) guns. HMS "M21" and HMS "M23" also had their 9.2 inch gun removed in 1917, receiving 7.5 inch guns.

The class also used a mixture of propulsion methods. HMS "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.

Service

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

HMS "M23", "M24", "M25" and "M27" also served in support of British and White Russian forces in the White Sea in May to September 1919.

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

Ships of the Class

*"M15" - Launched on April 28, 1915 and sunk by UC 38 November 11 1916.
*"M16" - Launched on May 3, 1915 and sold January 29, 1920.
*"M17" - Launched on May 12, 1915 and sold May 12 1920.
*"M18" - Launched on May 15, 1915 and sold January 29, 1920.
*"M19" - Launched on May 4, 1915 and sold May 12 1920.
*"M20" - Launched on May 11, 1915 and sold January 29, 1920.
*"M21" - Launched on May 27, 1915 and mined October 20 1918.
*"M22" - Launched on June 10 1915, renamed HMS "Medea" 1925 and sold December 1930
*"M23" - Launched on June 17 1915, renamed "Claverhouse" 1922 and sold 1959
*"M24" - Launched on August 9, 1915 and sold January 29, 1920.
*"M25" - Launched on July 24 1915 and scuttled September 16 1919
*"M26" - Launched on August 24 1915 and sold January 29, 1920.
*"M27" - Launched on September 8 1915 and scuttled September 16 1919
*"M28" - Launched on June 28 1915 and sunk January 20 1918

References

*Colledge
*Jane's Fighting Ships of World War One (1919), Jane's Publishing Company
*Dittmar, F. J. & Colledge, J. J., "British Warships 1914-1919", (Ian Allen, London, 1972), ISBN 0-7110-0380-7
*Gray, Randal (ed), "Conway's All The Worlds Fighting Ships, 1906-1921", (Conway Maritime Press, London, 1985), ISBN 0-85177-245-5