Yugoslav torpedo boat T5

The Yugoslav torpedo boat "T5 was a sea-going torpedo boat operated by the Royal Yugoslav Navy between 1921 and 1941. Originally 87 F", a 250t-class torpedo boat of the Austro-Hungarian Navy built in 1914–1915, she was armed with two guns and four torpedo tubes, and could carry 10–12 naval mines. She saw active service during World War I, performing convoy, patrol, escort and minesweeping tasks, anti-submarine operations and shore bombardment missions. Following Austria-Hungary's defeat in 1918, "87 F" was allocated to the Navy of the Kingdom of Serbs, Croats and Slovenes, which became the Royal Yugoslav Navy, and was renamed "T5". At the time, she and the seven other 250t-class boats were the only modern sea-going vessels of the fledgling maritime force.
During the interwar period, "T5" and the rest of the navy were involved in exercises of training and cruises to friendly ports, but activity was limited by reduced naval budgets. The ship was captured by the Italians during the German-led Axis invasion of Yugoslavia in April 1941. After her main armament was modernised, she served with the Royal Italian Navy under her Yugoslav designation, conducting coastal and second-line escort duties in the Adriatic Sea. Following the Italian capitulation in September 1943, she was returned to the Royal Yugoslav Navy-in-exile and served as "T5". At the end of the war, she was transferred to the new Yugoslav Navy and served as Cer until she was broken up in 1962.
Background.
In 1910, the Austria-Hungary Naval Technical Committee initiated the design and development of a coastal torpedo boat, specifying that it should be capable of sustaining for 10 hours. This specification was based on an expectation that the Strait of Otranto, where the Adriatic Sea meets the Ionian Sea, would be blockaded by hostile forces during a future conflict. In such circumstances, there would be a need for a torpedo boat that could sail from the Austro-Hungarian Navy () base at the Bay of Kotor to the Strait during the night, locate and attack blockading ships and return to port before morning. Steam turbine power was selected for propulsion, because diesels with the necessary power were not available, and the Austro-Hungarian Navy did not have the practical experience to run turbo-electric boats. Stabilimento Tecnico Triestino (STT) of Trieste was selected for the contract to build the first eight vessels, designated the T-group. Another tender was requested for four more boats, but when a competing boatbuilder, Ganz-Danubius, reduced their price by ten percent, a total of sixteen boats were ordered from them, designated the F-group. The F-group designation signified the location of Ganz-Danubius' main shipyard at Fiume.
Description and construction.
The 250t-class F-group boats had a waterline length of , a beam of , and a normal draught of . While their designed displacement was , they displaced about fully loaded. The crew consisted of 38–41 officers and enlisted men. The boats were powered by two AEG-Curtiss steam turbines driving two propellers, using steam generated by two Yarrow water-tube boilers, one of which burned fuel oil and the other coal. The turbines were rated at with a maximum output of and were designed to propel the boats to a top speed of . They carried of coal and of fuel oil, which gave them a range of at . The F-group had two funnels rather than the single funnel of the T-group. Due to inadequate funding, "87 F" and the rest of the 250t class were essentially coastal vessels, despite the original intention that they would be used for "high seas" operations. They were the first small Austro-Hungarian Navy boats to use turbines, and this contributed to ongoing problems.
The boats were armed with two Škoda L/30 guns, and four torpedo tubes. They could also carry 10–12 naval mines. "87 F" was laid down on 5 March 1914, launched on 20 March 1915 and completed on 25 October of that year.
Career.
World War I.
During World War I, "87 F" was used for convoy, patrol, escort and minesweeping tasks, anti-submarine operations, and shore bombardment missions. On 3 February 1916, "87 F" and two other 250t-class boats were involved in a shore bombardment operation against Ortona and San Vito Chietino, led by the armoured cruiser . Three days later, the scout cruiser , "87 F" and five other 250t-class boats were intercepted by the British light cruiser and French destroyer north of Durazzo in Albania, during which the only damage was caused by a collision between two of the other 250t-class boats. On 9 July, the scout cruiser led a force which included "87 F" and two s in a raid on the Otranto Barrage, the Allied naval blockade of the Strait of Otranto, which resulted in the sinking of two drifters. On 4 November, three Italian destroyers and three torpedo boats were involved in a brief encounter in the northern Adriatic with two Austro-Hungarian destroyers accompanied by "87 F" and two other 250t-class boats. The following day, the same three torpedo boats conducted a shore bombardment of Sant'Elpidio a Mare. In 1917, one of her 66 mm guns was placed on an anti-aircraft mount. On 28 November 1917, a number of 250t-class boats were involved in two shore bombardment missions. In the second mission, "87 F" joined seven other 250t-class boats and six destroyers for the bombardment of Porto Corsini, Marotta and Cesenatico.
By 1918, the Allies had strengthened their ongoing blockade on the Strait of Otranto, as foreseen by the Austro-Hungarian Navy. As a result, it was becoming more difficult for the German and Austro-Hungarian U-boats to get through the strait and into the Mediterranean Sea. In response to these blockades, the new commander of the Austro-Hungarian Navy, "Konteradmiral" Miklós Horthy, decided to launch an attack on the Allied defenders with battleships, scout cruisers, and destroyers. During the night of 8 June, Horthy left the naval base of Pola in the upper Adriatic with the dreadnought battleships and . At about 23:00 on 9 June 1918, after some difficulties getting the harbour defence barrage opened, the dreadnoughts and , escorted by one destroyer and six torpedo boats, including "87 F", also departed Pola and set course for Slano, north of Ragusa, to rendezvous with Horthy in preparation for a coordinated attack on the Otranto Barrage. About 03:15 on 10 June, while returning from an uneventful patrol off the Dalmatian coast, two Royal Italian Navy () MAS boats, "MAS 15" and "MAS 21", spotted the smoke from the Austrian ships. Both boats successfully penetrated the escort screen and split to engage the dreadnoughts individually. "MAS 21" attacked "Tegetthoff", but her torpedoes missed. Under the command of Luigi Rizzo, "MAS 15" fired two torpedoes at 03:25, both of which hit "Szent István". Both boats evaded pursuit. The torpedo hits on "Szent István" were abreast her boiler rooms, which flooded, knocking out power to the pumps. "Szent István" capsized less than three hours after being torpedoed. In October 1918, "87 F" was at Durazzo in Albania when the port was bombarded by a multinational Allied naval force. She escaped with minor damage, in what was the last major action involving the Austro-Hungarian Navy.
Interwar period.
"87 F" survived the war intact. In 1920, under the terms of the previous year's Treaty of Saint-Germain-en-Laye by which rump Austria officially ended World War I, she was allocated to the Kingdom of Serbs, Croats and Slovenes (KSCS, later Yugoslavia). Along with three other 250t-class F-group boats, "93 F", "96 F" and "97 F", and four 250t-class T-group boats, she served with the Royal Yugoslav Navy (, KJRM; Краљевска Југословенска Ратна Морнарица). Transferred in March 1921, in KJRM service, "87 F" was renamed "T5". In 1925, exercises were conducted off the Dalmatian coast, involving the majority of the navy. In May–June 1929, six of the eight 250t-class torpedo boats accompanied the light cruiser "Dalmacija", the submarine tender "Hvar" and the submarines and , on a cruise to Malta, the Greek island of Corfu in the Ionian Sea, and Bizerte in the French protectorate of Tunisia. It is not clear if "T5" was one of the torpedo boats involved. The ships and crews made a very good impression while visiting Malta. In 1932, the British naval attaché reported that Yugoslav ships engaged in few exercises, manoeuvres or gunnery training due to reduced budgets.
World War II and post-war service.
In April 1941, Yugoslavia entered World War II when it was invaded by the German-led Axis powers. At the time of the invasion, "T5" was assigned to the 3rd Torpedo Division located at Šibenik, which included her three former F-group sisters. On 8 April, the four boats of the 3rd Torpedo Division, along with other vessels, were tasked to support an attack on the Italian enclave of Zara on the Dalmatia coast. They were subjected to three Italian air attacks and, after the last one, sailed from the area of Zaton into Lake Prokljan, where they remained until 11 April. On 12 April, the 3rd Torpedo Division arrived at Milna on the island of Brač, and refused to follow orders to sail to the Bay of Kotor. All four former F-group boats were then captured by the Italians.
"T5" was then operated by the Italians under her Yugoslav designation, conducting coastal and second-line escort duties in the Adriatic. Her guns were replaced by two L/40 anti-aircraft guns, but no other significant alterations were made to her. After the Italians capitulated in September 1943, she was returned to the KJRM-in-exile in December of that year. "T5" was commissioned by the Yugoslav Navy after the war, and renamed "Cer". She was fitted with two guns on single mounts and one gun, and her torpedo tubes were also removed. She served until 1962, when she was broken up.