U3 1915
| Name | No | Yard No | Builder | Laid down | Launched | Comp | Fate |
| U3 | 135 | Germaniawerft, Kiel, Germany | 3/1907 | 20.8.1908 | 9/1909 | sunk 13.8.1915 | |
| U4 | 136 | Germaniawerft, Kiel, Germany | 3/1907 | 20.11.1908 | 8/1909 | to France 1920 |
|
Displacement normal, t |
240 / 300 |
|
Displacement full, t |
|
|
Length, m |
42.3 wl 43.2 oa |
|
Breadth, m |
3.65 |
|
Draught, m |
2.80 |
|
No of shafts |
2 |
|
Machinery |
2 Körting kerosene engines / 2 electric motors |
|
Power, h. p. |
600 / 340 |
|
Max speed, kts |
12 / 8.5 |
|
Fuel, t |
kerosene |
|
Endurance, nm(kts) |
1200(6) / 45(3) |
|
Armament |
2 - 450 TT (bow, 3) |
|
Complement |
21 |
| Diving depth operational, m | 30 |
Project history: Built by Germaniawerft at Kiel and towed to Pola via Gibraltar, they were of a double-hull type with internal saddle tanks. Although the German designers had evaluated the best hull-shaped in extensive model trials, these boats had constant troubles with their diving planes. The fins were changed in size and shape, and finally the bow planes were removed and a fixed stern flap was installed. Because of their greater displacement these boats had better seakeeping qualities and living conditions than their competitors. Considering that this was one of the first Germaniawerft designs, produced without extensive practical experience, these boats showed a high degree of effectiveness, and U4 had the longest operational history of all Austrian submarines.
Modernizations: 4.1915, U4: + 1 x 1 - 37/20 SFK L/23 H
1917, U4: - 1 x 1 - 37/20; + 1 x 1 - 66/24 G. L/26 K.15 BAK
Naval service: Both saw action during the war. U3 made an unsuccessful attack on the Italian armed merchant cruiser Città di Catania, was rammed and damaged, and when surfacing was hit by the French destroyer Bisson and sunk 13.8.1915. U4 was ceded as a war reparation to France and scrapped in 1920.
U4 1909
Many thanks to Wolfgang Stöhr for additional information on this page.
© Ivan Gogin, 2014