Fascinating article from “War History Online” about Royal Navy M Class submarines with 12 inch deck guns. Three were built between 1917 and 1918. The design was not effective.
Thanks to my special correspondent in New Orleans, Bob Warren, for sourcing this blog post.
M1 Submarine Monitor lost with all hands on 12 November 1925
“M1 was the only one to enter service before the end of World War I but did not see action. She was captained during her sea trials by experienced submariner Commander Max Horton after his return from the Baltic.”
(comments Charles McCain: Max Horton was one of the great fighting admirals of the Royal Navy. For most of World War Two he held the critical position of Commander-in-Chief Western Approaches. This command controlled all convoy escorts in the North Atlantic and was the largest operational command in the Royal Navy in World War Two–eventually comprising more than 300 warships). You can read my detailed article about Admiral Sir Max Horton here: http://tinyurl.com/MaxHorton-by-Charles-McCain
From “War History Online”
“During the last months of the first world war, the Royal Navy built the M-Class submarines. These were diesel-electric submarines with a rather unique feature; they had a 12-inch gun mounted in a turret forward of the conning tower and the M-class submarines are sometimes called submarine monitors.
They were initially intended to bombardment the enemies coast, but their role had been changed before detailed design begun. The new idea was that the submarine could engage merchant ships with the gun while remaining at periscope depth. Alternatively, it could surface and fire the gun, rather than with the use of torpedoes. At that time, torpedoes were considered ineffective against moving warships at more than 1,000 yards distance.”
Comments Charles McCain: “Monitors usually refer to surface ships built with one large gun and used to bombard enemy coast. The Royal Navy built a number of monitors in World War One. They would anchor in the English Channel off the coast of France or Belgium and fire on pre-designated targets. These monitors had large ballast tanks on both side of the hull under the waterline. Once anchored, the ships would flood the opposite ballast tanks from the direction of fire which had the effect of tilting the ship five or six degrees which gave the guns a longer range.
The generic name for monitors, comes from the USS Monitor of American Civil War fame.”