Undine 1939
| Name | No | Builder | Laid down | Launched | Comp | Fate |
| Undine | C48 | Vickers-Armstrong, Barrow | 2/1937 | 5/10/1937 | 8/1938 | sunk 7/1/1940 |
| Unity | C66 | Vickers-Armstrong, Barrow | 2/1937 | 16/2/1938 | 12/1938 | collision 29/4/1940 |
| Ursula | S65 - N65 | Vickers-Armstrong, Barrow | 2/1937 | 16/2/1938 | 12/1938 | to Soviet Union 5/1944 - 2/1949 (Â-4) (V-4), BU 5/1950 |
|
Displacement standard, t |
540 |
|
Displacement normal, t |
630 / 730 |
|
Length, m |
58.2 |
|
Breadth, m |
4.90 |
|
Draught, m |
4.62 |
|
No of shafts |
2 |
|
Machinery |
2 Paxman-Ricardo diesel-generators , 2 electric motors |
|
Power, h. p. |
615 / 825 |
|
Max speed, kn |
11.25 / 10 |
|
Fuel, t |
diesel oil 38 |
|
Endurance, nm(kts) |
4050(10) / |
|
Armament |
6 - 533 TT (4 bow, 2 ext bow, 10), 3 x 1 - 12.7/62 Ursula: 6 - 533 TT (4 bow, 2 ext bow, 8), 1 x 1 - 76/45 QF Mk I HA, 3 x 1 - 12.7/62 |
| Sensors | sonar |
|
Complement |
27 |
| Diving depth operational, m | 60 |
Ship project history: These submarines were originally reflected as unarmed targets for training of crews of escort ships. Already after design approval it was decided to arm them with TT. Construction of a fore end was changed for placing 4 TT in pressure hull and two more out of it, in a special fin. Single-hulled. Feature of this class that there on shafts only electric motors were and diesels used only in a role of generators. There were first British pure diesel-electric submarines.
New boats received a designation as "U" class, have appeared very successful, and better than boats of other types approached for actions in Mediterranean and Northern seas, however originally a series have limited to three units of the 1936 program.
Modernizations: about 1942 - 1943, Ursula: can carry 6 M2 mines instead of torpedoes
Naval service: Undine was sunk 7/1/1940 in North Sea by DCs of German minesweepers Ì1201, Ì1204 and Ì1207. Unity was lost 29/4/1940 at collision with s/s Atle Jarl in the North Sea.
Ursula 1940
© Ivan Gogin, 2008-10