The Birinci İnönü class was a pair of coastal submarines operated by the Turkish Navy between 1928 and the early Cold War. Their design was heavily based on the World War I-era Type UB III U-boat and built in the Netherlands to capitalize on German submarine experience. The boats, Birinci İnönü and İkinci İnönü, meaning "First İnönü" and "Second İnönü" respectively, had uneventful histories and operated with the Navy throughout the rest of the interwar period and World War II before they were decommissioned in the 1950s.
Development and design After World War I, the Allied powers seized the Ottoman Navy and reduced it to a small coastal force. The fleet remained under foreign control during the Turkish War of Independence and was returned to the new Republic of Turkey in 1922. Due to government instability and a lack of funds, the navy was initially a low priority. Four years later, efforts to rebuild the force began, which included repairs, refits, and an order for two new submarines. Design work for the two boats were undertaken by NV Ingenieurskantoor voor Scheepsbouw (IvS), a clandestine Dutch front company founded by officials intended to maintain German submarine experience to circumvent limitations introduced by the Treaty of Versailles. The design for the Turkish submarines was based on the World War I-era Type UB III coastal U-boat, as IvS used the opportunity to further develop and modernize the design for later German use. The submarines retained many characteristics from the Type UB III, but featured a second stern torpedo tube that was achieved by decreasing the diameter of each tube.
The class measured in length, with a beam of and a draught of . They displaced 507 tons surfaced and 620 tons submerged, with a complement of 29. Armament consisted of six torpedo tubes with four forward and two aft, a deck gun, and a anti-aircraft gun. Propulsion was provided by two MAN diesel engines and two electric motors producing and , respectively, which drove two propeller shafts. The submarines could achieve speeds of surfaced and submerged.
Service history After being ordered in 1925, the two submarines were built at Fijenoord in Rotterdam and constituted the first warships built for the Navy since before World War I. The boats were commissioned in 1928, were named Birinci İnönü and İkinci İnönü after the first and second battles of İnönü, and were sailed to Istanbul by German crews. The two boats remained in Turkish service for the next several decades, and were discarded sometime in the 1950s. +DataNameLaid downLaunchedCommissionedStrickenBirinci İnönü19261 February 192719281950İkinci İnönü192612 March 192719281950
References