These boats were built with a double hull in an attempt to improve on the saddle
tank design. Apart from an additional displacement of 50 tons and a stern
torpedo tube, they were very similar to the V Class submarines
Only three of the class were built, the first F1 being built at Chatham.
All three of the class survived the war and ended their service as training
boats at Campbeltown. F1 and F3 were scrapped in 1920, F2 was sold in 1922.
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| F Class: Information | |||
| Commissioned | 1915 to 1917 | ||
| Length (feet): | 151ft | ||
| Beam (feet): | 16ft ¾" | ||
| Surface Displacement (tons): | 353 | ||
| Submerged Displacement (tons): | 515 | ||
| Speed (knots): | Surface: 14.5 Dived: 8.75 | ||
| Armament: | 2 x 18" Bow Tubes; 1x 18" Stern Tube | ||
| Propulsion: | 2 x 900 hp Diesel Engines 2 x 400 hp Electric Motors |
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| Range | 3000 nm | ||
| Complement | 18 | ||