U-1 class submarine (Austria-Hungary)

SM U-1, the class leader, departs Pola in 1914.
Class overview
Builders:	Pola Navy Yard, Pola
Operators:	Austro-Hungarian Navy
Succeeded by:	U-3-class submarine
Built:	1907–09
In commission:	until 1918
Planned:	2
Completed:	2
Lost:	0
Scrapped:	2
Preserved:	0
General characteristics
Type:	submarine
Displacement:	As built: 229.7 t (226 long tons) surfaced 223.0 t (219 long tons) submerged After modernization: 248.9 metric tons (245 long tons) surfaced 277.5 metric tons (273 long tons) submerged
Length:	As built: 100 ft (30 m) After modernization: 100 ft 11 in (30.76 m)
Beam:	15 ft 9 in (4.80 m)
Draft:	12 ft 8 in (3.86 m)
Propulsion:	As built: 2 × shafts 2 × gasoline engines, 720 bhp (540 kW) total 2 × electric motors, 200 shp (150 kW) total After modernization: 2 × diesel engines (replaced the gasoline engines)
Speed:	10.3 knots (19.1 km/h) surfaced 6 knots (11 km/h) submerged
Range:	950 nmi (1,760 km) @ 6 knots (11 km/h), surfaced 40 nmi (74 km) @ 2 knots (3.7 km/h), submerged
Test depth:	40 meters (130 ft)
Complement:	17
Armament:	3 × 45 cm (17.7 in) torpedo tubes (two front, one rear); 5 torpedoes 1 × 37 mm (1.5 in) deck gun

The U-1 class was a class of two submarines or U-boats built for and operated by the Austro-Hungarian Navy (German: Kaiserliche und Königliche Kriegsmarine or K.u.K. Kriegsmarine). The U-1-class boats were built to an American design at the navy yard in Pola. The class was a part of the Austro-Hungarian Navy's efforts to competitively evaluate three foreign submarine designs.

The two U-1-class boats, both launched in 1909, were 100 feet (30 m) long and as built were each powered by two gasoline engines while surfaced, and two electric motors when submerged. Neither boat was operational at the beginning of World War I because both were in drydock awaiting replacement diesel engines for their problematic gasoline engines.

Beginning in 1915, both boats conducted reconnaissance cruises out of either Trieste or Pola until declared obsolete in early 1918. Both remained in service as a training boats at the submarine base on Brioni, but each was at Pola at the end of the war. They were ceded to Italy as war reparations in 1920 and scrapped at Pola. Neither submarine sank any ships during the war.

In 1904, after allowing the navies of other countries to pioneer submarine developments, the Austro-Hungarian Navy ordered the Austrian Naval Technical Committee (MTK) to produce a submarine design. The January 1905 design developed by the MTK and other designs submitted by the public as part of a design competition were all rejected by the Navy as impracticable. They instead opted to order two submarines each of designs by Simon Lake, Germaniawerft, and John Philip Holland for a competitive evaluation. The two Lake-designed submarines comprised the U-1 class. The Navy ordered plans for the building of two boats—designated U-1 and U-2—from the Lake Torpedo Boat Company of Bridgeport, Connecticut, in 1906.