X class

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X class
X craft in the Royal Navy Submarine Museum
X craft in the Royal Navy Submarine Museum
Overview
Type Small submarine
units 20 built, all out of service
period of service

1942-1945

Technical specifications
displacement

27 tons (surfaced)
30 tons (submerged)

length

15.62 meters

width

1.75 meters

Draft

1.60 meters

Diving depth 91.5 meters
crew

4 men

drive

1 Gardner diesel engine with 42 HP (31.3 kW)
1 Keith Blackman electric motor with 30 HP (22.3 kW) on a propeller

speed

6.5 knots (surfaced)
5.5 knots ( surfaced )

Range

1400  nautical miles (2520 km) surfaced
82 nautical miles (151.8 km) submerged at 2.2 kn

The X-class (also called X-crafts ) was a class of micro-submarines used by the Royal Navy for special operations during World War II . The most famous use of the boats was Operation Source in September 1943, during which the German battleship Tirpitz was badly damaged. From 1942 20 boats were built, two of which were prototypes and six for training purposes. Seven submarines were lost during various missions, the rest were decommissioned at the end of the war.

The only surviving X-class boat, the X24 , is in the Royal Navy Submarine Museum .

history

The boats were developed for special operations in coastal waters before the start of World War II. Construction of the two prototypes, the X3 and X4 , began in 1939, and they were operational in 1942. The first test drives took place in September and October 1942 off Scotland. In December 1942, Vickers-Armstrongs began building the first series boats.

technology

Crew member at the depth control

Hull and drive

The hull of the X-crafts was 15.62 meters long and 1.75 meters wide. The internal diameter of the pressure hull was 1.50 meters, the draft of the boat when surfaced was 1.60 meters. The surface displacement was 27, and 29.7 ts immersed . The pressure hull was built in three sections by different manufacturers (bow section: Thornycroft, middle section: Vickers-Armstrongs, stern section: Brigham & Cowan) and final assembly at Vickers-Armstrongs. The entire fuselage, which was made of steel plates with square reinforcing bars every 165 mm, was divided into four compartments: the engine room was in the stern, in front of it the command center. A narrow exit lock was attached to the command center, through which a diver could leave the boat. In the bow there was a small room that could be used as a bedroom and storage room. The boats possessed a retractable Barr & Stroud - periscope , navigation was a gyrocompass available. They were also equipped with hydrophones .

The boats were powered by a four-cylinder diesel engine with 42 hp from Gardner , as was also used in the London double-decker buses . The engine brought the boat to a top speed of 6.5 knots (12 km / h), the range was 1400 nautical miles . When diving, it was powered by a Keith Blackman electric motor with 30 hp. This drew its energy from a 112-cell lead-acid battery from Exide , which delivered 440 ampere hours . The battery cells were in the bow space of the submarine. The maximum speed with electric propulsion was 5.5 knots, the maximum range was at a speed of 2.2 knots at 82 nautical miles.

Armament and Crew

The armament of the submarines consisted of two side-mounted, dropable ground mines . The mines' charge consisted of 2032 kg of highly explosive Amatex explosives (mixture of 40% RDX , 40% TNT and 20% ammonium nitrate ), which were detonated by a time fuse . The mines were dropped using a hand crank inside the boats.

The crew of the boats consisted of four seamen during the mission. The commander was responsible for navigation and operation of the periscope, subordinate to him were the first lieutenant, who was responsible for command of the ship and operated the oars. The ship's engineer monitored the technical systems and was responsible for maintaining the engines. The fourth man, the combat diver , got out through the pressure lock; he was able to attach more detention mines to ships and was also responsible for cutting through barrier nets. The diver on board was dispensed with on transfer trips and when being towed into the operational area.

commitment

Due to the short range, the boats were mostly towed into the operational area by large S or T class submarines ; the boats only covered the last few kilometers on their own. On the return trip from the operational area, the tug submarines waited at a rendezvous point, from where they towed the boats back to the starting point.

The boats became known through the attack on the German battleship Tirpitz at its berth in the Kåfjord , a branch of the Altafjord , in Norway in September 1943. But they were also used during Operation Overlord , X20 and X23 marked the extreme left and right positions of the British-Canadian landing zone with position lights. The further developed successor boats of the XE class were used in the Pacific .

Web links

Commons : X class  - collection of pictures, videos and audio files

Individual evidence

  1. HMS X24 ( Memento of the original from March 9, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. on the website of the Royal Navy Submarine Museum @1@ 2Template: Webachiv / IABot / www.submarine-museum.co.uk
  2. ^ Peter Howard: Secret Operations. Underwater raid on Tirpitz . Ian Allen Publishing, Hersham 2006. ISBN 0711030936 . P. 28
  3. ^ Peter Howard: Secret Operations. Underwater raid on Tirpitz . P. 25