U-10-class submarine
The U-10 class was a class of five submarines or U-boats of the Austro-Hungarian Navy during World War I. The class was similar to the Type UB I submarine of the German Imperial Navy ; the first two boats delivered to Austria-Hungary had previously been commissioned in the German Navy.
The U-10 class as a whole did not have much wartime success, two of the boats sinking no ships. Only one boat, sank more than 1,000 combined tonnage of enemy ships. Of the five submarines of the class, only was sunk during the war; the remaining four were delivered as war reparations and broken up by 1920.
Background
The Austro-Hungarian Navy's U-boat fleet at the beginning of World War I consisted of six largely experimental submarines, two of which were not operational. The Navy did have five s under construction in Germany, but a perceived inability to sail the completed submarines past Gibraltar to the naval base at Pola led to a hasty decision to sell them to Germany, a severe setback for Austria-Hungary's U-boat fleet.In order to bolster their fleet, which had already been boosted by the recovery and commissioning of the French submarine as U-14 in 1915, the Austro-Hungarian Navy purchased five German UB-type coastal submarines, which had the advantages of short construction time and the ability to be shipped by rail—which avoided the perceived pitfalls of sea delivery. The first contract in February 1915 secured the purchase of and, initially commissioned as the German Type UB I U-boats and, respectively. A further contract on 1 April 1915, purchased three more boats,,, and.
Design and construction
The U-10-class boats were small coastal submarines that displaced surfaced and submerged. For propulsion, they featured a single shaft, a single diesel engine for surface running, and a single electric motor for submerged travel. The boats were capable of while surfaced and while submerged at a diving depth of up to. All five had slightly different conning tower configurations, but were all designed for a crew of 17 officers and men.The lead boat of the class, U-10, was built by Germaniawerft of Kiel, while the other four were constructed by AG Weser of Bremen. All five were transported by rail in sections to the navy yard at Pola, where they only needed riveting together to be complete, a process that typically took about two weeks.
U-10 was the first ship of the class launched, as the German UB-1 on 22 January 1915. The other four boats were launched by April. UB-1 and UB-15 were initially commissioned into the Kaiserliche Marine in January and April, respectively, each with German commanders and crew, but with an Austro-Hungarian Navy officer for piloting and training purposes, but both were commissioned into the K.u.K. Kriegsmarine with Austro-Hungarian crews by July. The other three ships were never manned by German crews and had all been commissioned by early October when each is listed in sources with a commanding officer.
Armament
The U-10-class boats were equipped with two torpedo tubes located in the front and carried a complement of two torpedoes. The German Type UB I submarines were additionally equipped with a machine gun, but it is not clear from sources if U-10 and U-11, the former German boats, were either equipped with them or, if so, retained them in Austro-Hungarian service. In October 1916, all the boats except U-11 received 37 mm/23 quick-firing guns. U-11 received a [Škoda 7 cm guns|]/18 gun originally planned for U-14. In November 1917, the 37 mm guns were replaced by [QF 3-pounder Hotchkiss|]/33 QF guns.War activities
All five boats of the U-10 class took part in the war, but, as a class, had limited success. Although UB-1 and UB-15 had each had sunk a single ship while commissioned in the German Imperial Navy during 1915, neither boat sank any ships in Austro-Hungarian service. U-17 sunk two ships, the unidentified sailing vessel, which sank on 1 January 1916 and the, which sank on 10 July 1916. U-16 sank or captured two small sailing ships in late 1915 and torpedoed and sank the on 16 October 1916. U-15 was the most successful of the class, sinking six ships for a total of and 745 tons. On a single day, 25 June 1916, U-15 sank the Italian auxiliary cruiser and the in the Strait of Otranto, accounting for almost half of her wartime successes.Of the five boats, only U-16 was sunk during the war, shortly after sinking Nembo. The only other casualty among the class involved U-10, which hit a mine near Caorle 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 incomplete at the war's end. After the end of fighting in November 1918, the four surviving class members—U-10, U-11, U-15, and U-17—were all turned over to Italy as war reparations and scrapped at Pola by 1920.