X1: Experimental Cruiser Submarine
During the First World War, German U-boats had great success sinking unescorted surface shipping with Gun action thus saving on the very expensive torpedoes.
Following the war, the British, French and Americans all experimented with Submarine Gun Cruisers. For the British, the submarine X1 was designed and laid down at No.7 Slipway Chatham Dockyard on 1st November 1921. Ordered under the 1921 - 1922 Naval estimates, the projected cost was £941,794 but with the many alterations during the build and trials, the actual cost was £1,044,158.
When X1 was launched, she was the largest submarine at sea.
The project was not a success and X1 became the only warship designed and built for the Navy after World War 1, to be scrapped before the start of World War II.
Constructed with a double hull, the external tanks carried most of the fuel, only 9% of the diesel being carried inside the pressure hull.
X1, by any standards was a very large submarine and the pressure hull was divided into 10 separate watertight compartments.
Designed to attack any armed merchant ship by Gun action alone, it was decided a 5.2" calibre gun was required. These were manufactured at Woolwich and two twin mounted guns were fitted. Each gun was capable of firing 6 rounds per minute with a range of 17,288 yards.
To man both guns from the magazine to the firing control took no less than 50 crew.
The two admiralty diesel engines, both built at Chatham, were designed to produce 3,000 bhp each. The generators for charging the batteries, were driven by two auxiliary diesel engines. These were MAN-type 6 cylinder engines which had been taken from U 126 after this boat had surrendered at the end of WW1.
Propulsion when submerged was supplied by four 600 bhp GEC Electric Motors. Each shaft being driven by two motors. These motors were the only part of the propulsion machinery that proved successful. Both the main and auxiliary diesels were constantly faulty and were the main reason for X1 being scrapped.
Following her commissioning, X1 sailed for trials. In 1926 she sailed for the Mediterranean where she remained until 1930. On her return to the UK, X1 went into refit and in 1933 went into reserve. The razor blade factory beckoned and she was scrapped in December 1936.
X1 was the last submarine to have only a number until numbering of submarines began again at the beginning of WWII.
For more information and pictures, select X1 from side menu. Only 16 of the 38 crew were saved.