 HMSM2 retrieving herParnall Petoseaplane. | |
| History | |
|---|---|
 United Kingdom | |
| Name | HMSM2 |
| Builder | Vickers |
| Laid down | 1916 |
| Launched | 19 October 1918 |
| Fate | Sank during exercise, 26 January 1932 |
| General characteristics | |
| Class & type | M-classsubmarine |
| Displacement |
|
| Length | 295 ft 9 in (90.14 m) |
| Beam | 24 ft 8 in (7.52 m) |
| Installed power |
|
| Propulsion |
|
| Speed |
|
| Range |
|
| Endurance | 80 nmi (92 mi; 150 km) at 2 kn (2.3 mph; 3.7 km/h) |
| Test depth | 200 ft (61 m) - accidentally reached 239 ft (73 m) in 1923 |
| Complement | 62 |
| Armament |
|
| Aircraft carried | 1 ×Parnall Petoseaplane |
| Aviation facilities | Hangar andHydraulic catapult |
HMSM2 was aRoyal Navysubmarinemonitor completed in 1919, converted in 1927 into asubmarine aircraft carrier. She was wrecked inLyme Bay,Dorset,Britain, on 26 January 1932. She was one of threeM-class boats completed.
Four M-class submarines replaced the order for the last fourK-class submarines,K17-K21. Although they were similar in size, the M class was an entirely different design from the K class, although it is possible that some material ordered for the K-boats went into them. In any event, the end of theFirst World War meant that only three were completed.
M2 was laid down atVickers shipyard atBarrow in Furness in 1916, and launched in 1918. Like the other members of her class, she was armed with a single fixed 12-inch (305mm) gun as well astorpedo tubes. The Mark IX gun was taken from spares held for theFormidable-classbattleships.
The M-class submarines were very large for the time at 296 feet (90 m) long. They were designed to operate as submarinemonitors orcruisers. Theydisplaced 1,600long tons (1,626 t) on the surface and 1,950 long tons (1,981 t) when submerged. Two 12-cylinderdiesel engines producing 2,400 hp (1,800 kW) drove them on the surface; underwater, they were driven by electric motors producing 1,500 hp (1,100 kW).
After the accidental sinking ofM1 in 1925,M2 and her sisterM3 were taken out of service and reassigned for experimental use. Her 12-inch gun was removed, replaced by a small aircrafthangar, the work being completed in 1927. This could carry a smallParnall Petoseaplane, specially designed for theM2, which, once its wings had been unfolded, could be lowered onto the sea alongside by aderrick for take off. On landing, the aircraft was hoisted back onto the deck and replaced into the hangar. In October 1928, ahydraulicaircraft catapult was fitted, to enable the seaplane to take off directly from the deck.[1] The submarine was intended to operate ahead of the battle fleet in areconnaissance role, flying off her unarmed seaplane as a scout.[2]
The concept of asubmarine cruiser was pursued withX1, but was not a success and was later abandoned.
M2 left her base atPortland on 26 January 1932, for an exercise inWest Bay, Dorset, carryingParnall Peto serial N255. Her last communication was a radio message at 10:11 to hersubmarine depot ship,Titania, to announce that she would dive at 10:30. The captain of a passing merchant ship, theNewcastlecoasterTynesider, mentioned that he had seen a large submarine dive stern first at around 11:15. Unaware of the significance of this, he only reported it in passing once he reached port.[3]
Her entire crew of 60 was killed in the accident.[4] The submarine was found on 3 February, eight days after her loss.[5]Ernest Cox, the salvage expert who had raised theGerman battleships at Scapa Flow, was hired to salvage theM2. In an operation lasting nearly a year and 1,500 dives, on 8 December 1932, she was lifted to within 20 ft (6 m) of the surface before agale sprang up, sending her down to her final resting place.
The hangar door was found open and the aircraft still in it. The accident was believed to be due to water entering the submarine through the hangar door, which had been opened to launch the aircraft shortly after surfacing.
Two explanations have been advanced;
The first is that since the crew were always trying to beat their record time for launching the aircraft, they had opened the hangar door on surfacing while the deck was still awash.
The other theory is that the flooding of the hangar was due to failure of the sternhydroplanes. High pressure air tanks were used to bring the boat to the surface in an awash condition, but to conserve compressed air, compressors were then started to completely clear the ballast tanks of water by blowing air into them. This could take as long as 15 minutes to complete. The normal procedure for launching the aircraft was therefore to hold the boat on the surface using the hydroplanes whilst the hangar door was opened and the aircraft launched. Failure of the stern hydroplanes would have sent the stern down as observed by the merchant officers and water would have eventually entered the hangar.
On 25 February 1932, a help message fromM2, written in pencil on a small piece of wood, was discovered by a fisherman on the shore atHallsands, southDevon. It read: "Help.M2 gone down. No. 2 hatch open.", with "Help. Lieut." on the back. It was handed over to the naval authorities and is now on display at theRoyal Navy Submarine Museum inGosport.[6]
The submarine currently lies upright on the sea bed at (50°34.6′N2°33.93′W / 50.5767°N 2.56550°W /50.5767; -2.56550). Her keel is about 100 ft (30 m) below the surface at low tide, and her highest point at the top of the conning tower at around 66 ft (20 m). She is a popular dive forscuba divers. The wreck is designated as a "protected place" under theProtection of Military Remains Act 1986.
After the loss ofM2, the Royal Navy abandoned submarine-launched aircraft, although other navies experimented with the concept in the inter-war years and with Japan producing some42 submarine aircraft carriers both before and during the Second World War.[7]
Shipwrecks and maritime incidents in 1932 | |
|---|---|
| Shipwrecks |
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| Other incidents |
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50°34′34″N2°32′55″W / 50.57611°N 2.54861°W /50.57611; -2.54861
