Swordfish 1939
| Name | No | Yard No | Builder | Laid down | Launched | Comp | Fate |
| Sturgeon | S73 - N73 | Chatham DYd | 1.1931 | 8.1.1932 | 2.1933 | to Netherlands 10.1943 - 9.1945 (Zeehond), BU 1.1946 | |
| Swordfish | S61 | Chatham DYd | 12.1930 | 10.11.1931 | 11.1932 | sunk 11.1940 | |
| Seahorse | S98 | Chatham DYd | 9.1931 | 15.11.1932 | 10.1933 | sunk 7.1.1940 | |
| Starfish | S19 | Chatham DYd | 9.1931 | 14.3.1933 | 10.1933 | sunk 9.1.1940 |
|
Displacement standard, t |
640 |
|
Displacement normal, t |
730 / 927 |
|
Length, m |
61.7 |
|
Breadth, m |
7.32 |
|
Draught, m |
3.63 |
|
No of shafts |
2 |
|
Machinery |
2 Admiralty diesels / 2 electric motors |
|
Power, h. p. |
1550 / 1440 |
|
Max speed, kn |
13.75 / 10 |
|
Fuel, t |
diesel oil 44 |
|
Endurance, nm(kts) |
3800(10) / |
|
Armament |
Sturgeon, Swordfish: 1 x 1 - 76/45 20cwt QF Mk II (HA), 1 x 1 - 12.7/62, 6 - 533 TT (bow, 12), Seahorse, Starfish: 1 x 1 - 76/45 20cwt QF Mk II, 1 x 1 - 12.7/62, 6 - 533 TT (bow, 12), |
| Sensors | type 120 sonar |
|
Complement |
38 |
| Diving depth operational, m | 60 |
Project history: In 1930, according to the plan of submarine forces modernization, Admiralty has made a decision to start building submarines for replacing of the outdated "�" class. New boats should have medium dimensions, speed, armament and endurance, exceeding corresponding "�" class indicators, but at the same time comparable with latter on manoeuvrability and a diving time. The design of new "S" class had approved the same year and building of 4 boats was started under 1929 and 1930 Programmes.
Submarines were saddle-tank type, with fuel tanks arranged inside pressure hull, designed diving depth was 95m. Diving time was 25-30sec. Swordfish and Sturgeon differed by original folding into special "well", 76mm gun mounting. Latter had appeared unsuccessful and was soon been replaced by standard not retracted one.
Modernizations: 1942-1943, Sturgeon: + type 286W or type 291W radar
1/1946, Sturgeon: 1 x 1 - 76/45 CP Mk V, 6 - 533 TT, type 286W or type 291W radar, type 120 sonar
Naval service: Seahorse was lost on a mine in the North Sea (possibly 7.1.1940). Starfish was sunk 9.1.1940 by DCs of German minesweeper �7 in the North Sea. Swordfish was lost 16.11.1940 on a mine in the North Sea.
Sturgeon 1933
� Ivan Gogin, 2008-10