SM U-28 (Austria-Hungary)

Austria-Hungary's U-boat fleet was largely obsolete at the outbreak of World War I.[4] The Austro-Hungarian Navy satisfied its most urgent needs by purchasing five Type UB I submarines that comprised the U-10 class from Germany,[5] by raising and recommissioning the sunken French submarine Curie as U-14,[4][Note 1] and by building four submarines of the U-20 class that were based on the 1911 Danish Havmanden class.[2][Note 2]

After these steps alleviated their most urgent needs,[4] the Austro-Hungarian Navy selected the German Type UB II design for its newest submarines in mid 1915.[6] The Germans were reluctant to allocate any of their wartime resources to Austro-Hungarian construction, but were willing to sell plans for up to six of the UB II boats to be constructed under license in Austria-Hungary.[6] The Navy agreed to the proposal and purchased the plans from AG Weser of Bremen.[7]

U-28 displaced 264 metric tons (260 long tons) surfaced and 301 metric tons (296 long tons) submerged.[2] She had a single hull with saddle tanks,[8] and was 121 feet 1 inch (36.91 m) long with a beam of 14 feet 4 inches (4.37 m) and a draft of 12 feet 2 inches (3.71 m).[2] For propulsion, she had two shafts, twin diesel engines of 270 brake horsepower (200 kW) for surface running, and twin electric motors of 280 shp (210 kW) for submerged travel. She was capable of 9 knots (17 km/h; 10 mph) while surfaced and 7.5 knots (13.9 km/h; 8.6 mph) while submerged.[2] Although there is no specific notation of a range for U-28 in Conway's All the World's Fighting Ships 1906–1921, the German UB II boats, upon which the U-27 class was based, had a range of over 6,000 nautical miles (11,000 km; 6,900 mi) at 5 knots (9.3 km/h; 5.8 mph) surfaced, and 45 nautical miles (83 km; 52 mi) at 4 knots (7.4 km/h) submerged.[8] U-27-class boats were designed for a crew of 23–24.[2]

U-28 was armed with two 45 cm (17.7 in) bow torpedo tubes and could carry a complement of four torpedoes. She was also equipped with a 75 mm (3.0 in)/26 caliber deck gun and an 8 mm (0.31 in) machine gun.[2]

After intricate political negotiations to allocate production of the class between Austrian and Hungarian firms,[6] U-28 was ordered from Cantiere Navale Triestino (CNT) on 12 October 1915.[1] She was laid down by early 1916 at the Pola Navy Yard,[Note 3] and launched on 8 January 1917.[2]

After her completion, U-28 was commissioned into the Austro-Hungarian Navy on 26 June 1917 under the command of Linienschiffsleutnant Zdenko Hudeček.[3] Previously in command of U-17, Hudeček was a 30-year-old native of Theresienstadt (present-day Terezín in the Czech Republic).[9] Four days after the U-boat's commissioning, Hudeček achieved his first kill at the helm of U-28. On 30 June, while on patrol about 40 nautical miles (74 km) east of Malta, U-28 came upon the 4,809 GRT British steamer Haigh Hall. The turret hull ship was carrying wheat from Bombay to Naples when torpedoed and sunk by Hudeček.[10] Three days later, the British India passenger ship Mongara met the same fate. Even though escorted by an Italian destroyer and a trawler,[11] Mongara was torpedoed and sunk by U-28 just 1.5 nautical miles (2.8 km) from the breakwater at Messina.[12] The 8,205 GRT liner—the largest ship sunk by U-28[13]—was en route from Sydney to London when she went down, but was spared any loss of life in the attack.[12] In eight days in commission, U-28's tally was over 13,000 GRT,[13] already exceeding the totals of all four U-boats of the U-20 class.[4]

The following month, U-28 sank the 3,881 GRT collier Maston 35 nautical miles (65 km) from Cape Spartivento, Calabria, on 13 August, killing two men of the British ship's crew.[14] Three days after Maston went down, U-28 sank HMS Bradford City, a 3,683 GRT British Q ship in the Straits of Messina, with no loss of life.[15] HMS Bradford City, operating under the pseudonym Saros, had been particularly detached to the Straits to hunt U-28 and had ignored orders to proceed to port from officers unaware of her naval status. After the torpedo struck, the ship's "panic party" had taken to the boats in the hope of luring her attacker to the surface, but the arrival of the French naval trawler Hiver drove U-28 away before the gun crews aboard HMS Bradford City could engage the submarine. HMS Bradford City sank within 30 minutes off San Remo.[16] In October, U-28 closed out her 1917 list of victims with Bontnewydd, a British steamer sunk 60 nautical miles (110 km) north-northeast of Susa. The 3,296 GRT steamer was sailing in ballast from Marseilles for Karachi.[17]

In January 1918, U-28 sank an additional three ships. Bosforo, an Italian steamer of 2,723 GRT headed for Salonika, was sent to the bottom near Cape Spartivento on 12 January.[18] The following day, U-28 dispatched the British steamer Rapallo 1.5 nautical miles (2.8 km) south of Cape Peloro. One sailor aboard the one-year-old ship died in the attack, which occurred while the ship was headed to Messina in ballast.[19] On 21 January, West Wales, a collier headed from Barry to Alexandria, was sunk 140 nautical miles (260 km) from Malta, taking her load of coal and two of her crew to the bottom.[20]

On 8 March, U-28 attacked two ships, sinking one of them. The first ship, Mitra, a 5,592 GRT tanker was hit by U-28 but was able to make port in Malta with her cargo of oil.[21][Note 4] Later in the month, U-28 sank Uganda 32 nautical miles (59 km) from Linosa, killing one sailor in the attack. The 1905 British ship was carrying cotton and cottonseed from Alexandria for London when the attack occurred.[22] Three days later, Stolt Nielsen, a 5,684 GRT steamship, was sent to the bottom 38 nautical miles (70 km) from Malta. Carrying a general cargo for the Admiralty when she went down, the British ship turned out to be the final ship to be sunk by U-28.[13][23]

At the war's end, U-28 was surrendered to Italy at Venice in 1919. Later awarded to Italy as a war reparation, she was scrapped at Venice in 1920.[2] In her 18-month career, U-28 sank ten ships with a combined tonnage of 44,743, and damaged an eleventh.[13]