HM Submarine X1

"for the midget submarine of the Second World War, see X class submarine"

HM Submarine "X1" was conceived and designed as a submersible commerce raider for the Royal Navy, and at the time of her launching was the largest submarine in the world. The idea of a submarine cruiser had been mooted as early as 1915, but was not put into practice until 1921.

X1, which was based on the uncompleted German U-173 class, was laid down on November 2 1921 at the Naval Dockyard Chatham and completed on September 23 1925, commissioning in December 1925.

The 1922 Washington Naval Treaty, of which Britain was a signatory, did not ban submarines but it did ban their use against merchant ships, which was X1's unacknowledged purpose; its armament had been designed to successfully engage the classes of vessels likely to be escorting convoys, such as destroyers and frigates. Therefore, a certain amount of secrecy surrounded X1, the government even going to the lengths of taking a national newspaper to court over its pictures of the new submarine following her launch, all copies of the paper being seized.

Description

Propulsion

The main engines were two 8-cylinder Admiralty Diesel engines with a total output of convert|3000|hp|kW. Two auxiliary convert|1200|hp|kW MAN Diesel engines taken from U-126 were installed for battery charging purposes. For underwater propulsion, four GEC electric motors of convert|600|hp|kW each were fitted. It was hoped to achieve over convert|8000|hp|kW using both Diesels and electric motors together, but the highest power achieved (during a fill power trial in March 1926) was convert|7441|hp|kW.

In theory she could make convert|19.5|kn|km/h on the surface, and at economical speed she had a greater range than normal cruisers, but unfortunately her diesel engines suffered from continual mechanical problems. The X1's average diving time (to periscope depth) was 2 minutes 20 seconds. Her handling underwater was considered superior to other submarines of the period.

Armament

Besides her six 21-inch bow torpedo tubes she carried four 5.2in/42 QF Mk I guns in twin unarmoured mounts, one forward and one aft of the conning tower. Working and control of the guns required no less than 58 crewmen. X1 was intended to be able to sink or disable a destroyer at a range of convert|6000|yd|m with her guns alone, but in practice this was unlikely, as the low height above the water of her range-finding equipment and the unsteady nature of a submarine made her inherently unsuitable as a gun platform.

Fate

"X1" was placed in Reserve in 1933, taken off the active list in 1936, and finally scrapped at Pembroke on December 12 1936. As such she became the only vessel designed, built for and scrapped by the Royal Navy between the two World Wars.

ee also

*British M class submarine - an earlier attempt at a gun equipped submarine
* Surcouf - a similar French large gun-armed submarine

Notes

References

*cite book | last = Akermann | first = Paul | authorlink = | coauthors = | title = Encyclopedia of British Submarines 1901-1955 | publisher = Periscope Publishing Ltd. | date = 2002 | location = | pages = | url = | doi = | id = | isbn = 1904381057
*cite book | last = Compton-Hall | first = Richard | authorlink = Richard Compton-Hall | coauthors = | title = Submarine warfare, Monsters and midgets | publisher = Blandford Press | year = 1985 | location = | pages = | url = | doi = | id = | isbn = 0 7137 1389 5
* [http://www.submariners.co.uk/Boats/DB/index.php?choice=X1&seln=Boat&ID=291#291 Submariners.co.uk Boat database]