RN Monitors: M15 Class 1915

[jbryce1437]

The fourteen 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 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 & 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 Triumph, 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 Swiftsure.
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. Some photos of the class:

HMS M15

HMS%20M15-1-1915-1917TZ[1].jpg

HMS M15-at mudros1a.jpg

HMS M16

m16 at mudros 1915.jpg

m16-monitor.jpg

Tiga at Sydney.jpg

FRANCONIA at Circular Quay in Sydney 1927 with tiga ex m16.jpg

HMS M17

HMS%20M17-3-1915-1920TZ[1].jpg

Monitor%20M17-01[1].jpg

HMS M18

Monitor%20M18-01[1].jpg

HMS M19

HMS M19-3.jpg

Pearl m19-m33-m16-m20-m17-at-stavros early 1918.jpg

HMS M20

m20-off-anzac-aug-1915.jpg

HMS%20M20-2-1915-1920TB-FIRING%209.2%20INCH%20GUNS[1].jpg

HMS M21

M21 trials 1915[1].jpg

M21 trials 1915[2].jpg

m21%20on%20trials%20off%20tees%20july%201915TZ[1].jpg

m21-monitor.jpg

HMS M22 (later Medea)

m22-22[1].JPG

medea-ex-m22-aground-22-jan.jpg

HMS M23 (photo wanted)


HMS M24

m24-off-dover-oct-1918.jpg

M24[1].jpg

Satoe ex HMS M24-1.jpg

Satoe ex HMS M24-2.jpg

HMS M25

M25.jpg

HMS M26

HMS%20M26-1-1915-1920-19TB-PRIV-PORTSMOUTH.[1].jpg

monitor m26.jpg

Monitor%20M26-01[1].jpg

HMS M27

HMS Monitor on Dvina River 1.jpg

m27-sunk-at-river-dvina-16-s.jpg

m27-m31-m33-at-shestakovo-j.jpg

HMS M28

m28-at-mudros.jpg

Full specification of the class here

[Brian James]

M15 Class Monitor HMS M21 pictured on sea trials in 1915..Intended as a shore bombardment vessel, M21's primary armament was a single 9.2 inch Mk VI gun removed from the Edgar Class Cruiser HMS Theseus. In addition to her 9.2 inch gun, she also possessed one 12 pounder and one six pound anti-aircraft gun. Due to the shortage of Bolinder diesel engines that equipped her sisters, she was fitted with 2 shaft triple expansion steam engines that allowed a top speed of eleven knots. The Monitor's crew consisted of sixty nine officers and men. M21 served initially in the Mediterranean from September 1915. On her return from the Mediterranean in September 1917, M21 had her main 9.2 inch gun removed, as it was required for artillery use on the Western Front, and a BL 7.5-inch Mk III 50-caliber gun was fitted in lieu. M21 then served with the Dover Patrol from October 1917. M21 struck a mine off Ostend on October 20th 1918. She was taken in tow to Dover, but sank off West Pier.

[emason]

In addition to her 9.2 inch gun, she also possessed one 12 pounder and one six pound anti-aircraft gun.

Unusual for a WW1 vessel to have an AA gun. Why would she need this?