Bizarre? Wild? Outlandish? Well, I am talking about real ships. Very real and very unlucky.
In February 1916 Vickers received an order to build a boat to the new design. K18 was remodeled and became M1. Another boat, M2 (ex K19) was ordered from Vickers in May 1916 and two more, M3 (ex K20) and M4 (ex K21), from Armstrong Whitworth in August 1916.
The fact that the M Class design got further than the conference table is a reflection of the failure by the Admiralty to recognise the proper nature of submarine operations. Although their 12-inch guns were ideally suited for bombarding coastal defences, their method of attack at sea was rather primitive. The attack procedure was to cruise at periscope depth until the target was lined up'. The submarine was then brought-up until about six feet of the gun barrel protruded from the water. A round was fired and the submarine would then make a rapid dive - unable to fire again as the gun could not be reloaded under water. Known as the 'dip-chick' method, this attack procedure took about 30 seconds to complete. At that time torpedoes were considered ineffective against moving warships at more than 1000 yards (900 m). Nevertheless it is unlikely that a well-constructed ship would be sunk by a single 12-inch (305 mm) shell hit.
On October 25th, 1925, M1 was rammed by a Swedish collier, SS Vidar, off Start Point and was lost with all hands.The wreck of M1 was discovered by a diving team led by Innes McCartney in 1999 at a depth of 73 metres. Later that year the wreck was visited again by Richard Larn and a BBC TV documentary crew, and the resulting film was aired in March 2000.
M2 was converted to a seaplane carrier in 1925, a hangar replacing the gun turret, and a catapult to launch a small Parnall Peto seaplane.
She was lost off Chesil Beach on 26 January 1932. It is thought that the hangar door was opened prematurely. M2 lies in much shallower water, 32 metres deep with the top of the conning tower only 20 metres below the surface at low tide. She is a popular attraction for local scuba divers with as many as six boats anchored above her on busy days.
During her service she was quite popular with the photographers - there are more pictures of M2 than of her two sister ships together. Let's see some:
M3 was converted to a minelayer in 1927 with stowage for 100 mines, primarily to test the mine-handling equipment of the Porpoise class. The mines were carried on a conveyor belt which ran along her upper deck and covered over by an enlarged casing. The mines were laid through a door at the stern. She was scrapped in 1932 after the trials had been completed.
So, this was the story of the Royal Navy most unlucky submarine class (although some authors tend to call each converted submarine a class of its own). Wild ideas that emerged on the dawn of Diesel Era proved not only costly but lethal.