U-10 was a small, coastal submarine that displaced surfaced and submerged. She featured a single shaft, a single Daimlerdiesel engine for surface running, and a single electric motor for submerged travel. U-10 was capable of up to while surfaced and while submerged at a diving depth of up to. She was designed for a crew of 17 officers and men. U-10 was equipped with two torpedo tubes located in the front and carried a complement of two torpedoes. German Type UB I submarines were additionally equipped with a machine gun, but it is not clear from sources if U-10, as a former German boat, was either equipped with one or, if so, retained it in Austro-Hungarian service. In October 1916, U-10s armament was supplemented with a 37-mm/23 quick-firing gun. This gun was replaced by a QF 3-pounder Hotchkiss#Austro-Hungarian service|/33 QF gun in November 1917. Construction of UB-1 was started on 1 November 1914 at Germaniawerft in Kiel. After her assembly was complete UB-1 was launched on 22 January 1915. After extended negotiations between Austria-Hungary and Germany, in March 1915 it was decided for Germany to supply five submarines of the UB I type. This model was familiar to the Austro-Hungarian Navy since the Imperial German Navy had reassembled UB3, UB 8, and UB 9 at the Pola Navy Yard. The first boat was bought on April 4, 1915, a "sample" UB 1 boat. This submarine was shipped by rail in sections to Pola, where the sections were riveted together. Though there is no record of how long it took for UB-1s parts to be assembled, a sister boat,, shipped from Germany in mid-April 1915, was assembled in about two weeks.
Operational history
SM UB-1 was commissioned into the German Imperial Navy under the command of Oberleutnant zur See Franz Wäger on 29 January. An Austro-Hungarian Navy officer was assigned to the boat for piloting and training purposes. On 26 June 1915, UB-1 sank an Italian torpedo boat 5 PN in the Gulf of Venice. On 4 June 1915, after being disassembled into three sections and transported by rail to Pola for reassembling, UB-1 was handed over to the Austro-Hungarian Navy and commissioned as U-10 under the command of Linienschiffsleutnant Karl Edler von Unczowski. British submarine had an encounter with U-10 on 11 May 1917. While cruising off Pola, H4 came across U-10 and fired a spread of two torpedoes at the submarine. The torpedoes were aimed to be 5° apart at a distance of which was apparently too wide, because the captain of H4 observed the torpedoes miss just ahead and just astern of U-10. On 9 July 1918, U-10 hit an Italian mine near Caorle in the northern Adriatic Sea at position, and was beached with heavy damage. Although she was looted by Austro-Hungarian Army troops, she was later towed to Trieste for repairs, which remained unfinished at war's end; all of the 13 crew personnel were saved. U-10 was handed over to Italy as a war reparation and scrapped at Pola by 1920. U-10 sank no ships in her Austro-Hungarian service.