# Type UC I submarine

The Type UC I coastal submarines were a class of small minelaying U-boats built in Germany during the early part of World War I. They were the first operational minelaying submarines in the world (although the Russian submarine Krab was laid down earlier). A total of fifteen boats were built. The class is sometimes also referred to as the UC-1 class after SM UC-1, the class leader. The Italian X-class submarine was a reverse-engineered and modified type of the UC-1-class.

## Design

These submarines were designed by Dr. Werner of the Torpedo Inspectorate, and based on the Type UB I small coastal submarines, with a revised bow section housing inclined minelaying tubes and uprated engines to compensate for the increased displacement and less streamlined form. The boats' sole armament was six internal mine tubes with 12 mines, although UC-11 was fitted with a single external torpedo tube in 1916. They were constructed very quickly, and suffered from problems with their minelaying system, which in some cases caused the mines to become armed before exiting their tubes and explode prematurely.
Type UC I submarines had a displacement of 168 tonnes (165 long tons) when at the surface and 183 tonnes (180 long tons) while submerged. They had a length overall of 33.99 m (111 ft 6 in), a beam of 3.15 m (10 ft 4 in), and a draught of 3.04–3.06 m (10 ft 0 in – 10 ft 0 in). The submarines were powered by one Daimler-Motoren-Gesellschaft or Benz six-cylinder, four-stroke diesel engine producing 80–90 metric horsepower (59–66 kW; 79–89 shp), an electric motor producing 175 metric horsepower (129 kW; 173 shp), and one propeller shaft. They were capable of operating at a depth of 50 metres (160 ft).
The submarines had a maximum surface speed of 6.20–6.49 knots (11.48–12.02 km/h; 7.13–7.47 mph) and a maximum submerged speed of 5.22–5.67 knots (9.67–10.50 km/h; 6.01–6.52 mph). When submerged, they could operate for 50 nautical miles (93 km; 58 mi) at 4 knots (7.4 km/h; 4.6 mph); when surfaced, they could travel 780–910 nautical miles (1,440–1,690 km; 900–1,050 mi) at 5 knots (9.3 km/h; 5.8 mph). They were fitted with six 100 centimetres (39 in) mine tubes, twelve UC 120 mines, and one 8 millimetres (0.31 in) machine gun. They were built by AG Vulcan Stettin or AG Weser Bremen and their complement was fourteen crew members.

## List of Type UC I submarines

A total of 15 Type UC I submarines were built.
* SM UC-1, possibly struck a mine off Nieuport, 19 July 1917
* SM UC-2, sunk by detonation of its own mines off Yarmouth, 30 June 1915
* SM UC-3, struck a mine off Zeebrugge, 27 May 1916
* SM UC-4, scuttled off the coast of Flanders, 5 October 1918 during the German evacuation from Belgium
* SM UC-5, grounded on the Shipwash Shoal 27 April 1916; scuttled but charges failed to explode
* SM UC-6, sunk in a mined net off North Foreland, 27 September 1917
* SM UC-7, possibly struck a mine north of Zeebrugge, 3 July 1916
* SM UC-8, ran aground on Dutch coast, 14 November 1915. Interned by Netherlands and served in Dutch Navy as the HLNMS M-1 until broken up in 1932
* SM UC-9, missing after 20 October 1915; possibly sunk by its own mine
* SM UC-10, torpedoed and sunk by British submarine HMS E54 21 August 1916, off Dutch coast
* SM UC-11, struck a mine and blew up in Strait of Dover, 16 June 1918
* SM UC-12, sunk by detonation of its own mines, 16 March 1916 near Taranto; salvaged and repaired by Italy as X1 (scrapped 1919)
* SM UC-13, ran aground in a storm east of the Bosporus, 29 November 1915
* SM UC-14, struck a British mine off Zeebrugge, 3 October 1917
* SM UC-15, missing after 7 November 1916, probably off the mouth of the Danube