Porpoise
| Type |
SS |
| Country |
UK |
| Displacement (t) |
2,450 |
| Length (m) |
88.0 |
| Beam (m) |
8.1 |
| Draft (m) |
5.5 |
| Height (m) |
8.1 |
| Max speed submerged (kn) |
17.0 |
| Max speed surfaced (kn) |
12.0 |
| Max safe depth (m) |
122 |
| Endurance (days) |
50 |
| Diesel-electric |
Yes |
| Titanium hull |
No |
| Class year |
1956 |
Individual hulls (8)
| Name |
Short name |
Country |
Commissioned |
Decommissioned |
Remark |
| S01 Porpoise |
HMS Porpoise |
UK |
1958-04-17 |
1982-01-01 |
|
| S02 Rorqual |
HMS Rorqual |
UK |
1958-10-24 |
1977-05-05 |
|
| S03 Narwhal |
HMS Narwhal |
UK |
1959-05-04 |
1977-02-10 |
|
| S04 Grampus |
HMS Grampus |
UK |
1958-12-19 |
1980-01-01 |
|
| S05 Finwhale |
HMS Finwhale |
UK |
1960-08-19 |
1988-01-01 |
|
| S06 Cachalot |
HMS Cachalot |
UK |
1959-09-01 |
1979-11-12 |
|
| S07 Sealion |
HMS Sealion |
UK |
1961-07-25 |
1987-01-01 |
|
| S08 Walrus |
HMS Walrus |
UK |
1961-02-10 |
1987-01-01 |
|