Porpoise 1958
| Name | No | Yard No | Builder | Laid down | Launched | Comp | Fate |
| Porpoise | S01 | Vickers-Armstrong, Barrow | 15.6.1956 | 25.4.1956 | 16.4.1958 | for disposal 1983, sunk as target 1985 | |
| Rorqual | S02 | Vickers-Armstrong, Barrow | 15.1.1955 | 5.12.1956 | 24.10.1958 | BU 5.1977 | |
| Narwhal | S03 | Vickers-Armstrong, Barrow | 15.3.1956 | 25.10.1957 | 4.5.1959 | scuttled 3.8.1983 | |
| Grampus | S04 | Cammell Laird, Birkenhead | 16.4.1955 | 30.5.1957 | 19.12.1958 | harbour TS 1976 | |
| Finwhale | S05 | Cammell Laird, Birkenhead | 18.9.1956 | 21.7.1959 | 19.8.1960 | harbour TS 1979 | |
| Cachalot | S06 | Scotts, Greenock | 1.8.1955 | 11.12.1957 | 1.9.1959 | sold 11.1979 | |
| Sealion | S07 | Cammell Laird, Birkenhead | 5.6.1958 | 31.12.1959 | 25.7.1961 | sold 7.1988 | |
| Walrus | S08 | Scotts, Greenock | 12.2.1958 | 22.9.1959 | 8.2.1961 | sold 1987 |
|
Displacement standard, t |
1565 |
|
Displacement normal, t |
1975 / 2303 |
|
Length, m |
73.4 pp 88.5 oa |
|
Breadth, m |
8.10 |
|
Draught, m |
5.60 |
|
No of shafts |
2 |
|
Machinery |
2 16-cyl ASR 1 diesels / 2 English Electric electric motors |
|
Power, h. p. |
3680 / 6000 |
|
Max speed, kts |
12 / 17 |
|
Fuel, t |
diesel oil 258 |
|
Endurance, nm(kts) |
9000(12) / |
|
Armament |
8 - 533 TT (6 fwd, 2 aft, 30) |
|
Electronic equipment |
type 1002 radar, type 186, type 187, type 2007 sonars, UAH ECM suite |
|
Complement |
71 |
|
Diving depth operational, m |
200 |
Project history: Apart from the experimental Explorer class these were the first British postwar submarines and they incorporated experience gained from wartime operations, trials with surrendered U-boats and the 'T Conversions"; the first batch was ordered in April 1951. They proved a great success (mainly because they were very quiet) and only started to go out of service because the 1975 Defence Review cut back the operational strength of the RN and because the new nuclear boats were making demands on manpower.
The two sets of batteries were linked in series to give 880V for short bursts of high speed. They had a range of 9000nm on the surface, sufficient for world-wide deployment. Mk 8 and Mk 20 torpedoes were carried. Sealion and Walrus were ordered to the Oberon design on 11 February 1954, and the rest on 19 April 1951.
Modernizations: None.
Naval service: No significant events.
Porpoise 1966
© Ivan Gogin, 2015