NAVYPEDIA

Photo

Bonita

Ships

No	Name	Yard No	Builder	Laid down	Launched	Comm	Fate
SF4, 7.1931- SS163	V1, 3.1931- Barracuda		Portsmouth N Yd	10/1921	17.7.1924	10.1924	sold 11.1945
SF5, 7.1931- SS164	V2, 3.1931- Bass		Portsmouth N Yd	10.1921	27.12.1924	9.1925	stricken 3.1945
SF6, 7.1931- SS165	V3, 3.1931- Bonita		Portsmouth N Yd	11.1921	9.6.1925	5.1926	stricken 3.1945

Technical data

Displacement standard, t
Displacement normal, t	2119 / 2506
Length, m	99.1 wl 102.0 oa
Breadth, m	8.41
Draught, m	4.62
No of shafts	2
Machinery	2 Sulzer diesels + 2 Sulzer diesel-generators / 2 electric motors
Power, h. p.	6200 / 2400
Max speed, kts	18.7 / 9
Fuel, t	diesel oil 364
Endurance, nm(kts)	12000 (11) / 10 (8)
Armament	1 x 1 - 127/51 Mk 9, 6 - 533 TT (12, 4 bow, 2 stern)
Electronic equipment	SC sonar
Complement	85
Diving depth operational, m	60

Standard scale images

Graphics

Project history

Ocean-going submarines, project was developed from last series of S class. Submarines were built within the limits of the program of 1916.

Double-hulled. Machinery was of combined type: besides main propulsion diesels with a direct drive there were also two diesels-generators, used both for battery recharge, and for cruise speed using electric drive.

Despite appreciable high endurance and a high speed, in comparison with S class submarines, these ships because of bad manoeuvrability were considered mediocre enough. In a beginning of war it was supposed to rebuild them to transports, however this project remained.

Modernizations

1928, all: - 1 x 1 - 127/51; + 1 x 1 - 76/50 Mk 17/18

1940, all: Sulzer diesel-generators were replaced by more powerful MAN; - SC sonar; + WBA sonar

1943, all: - 1 x 1 - 76/50; + 2 x 1 - 20/70 Mk 4, SD, SJ radars

Naval service

Bass in August, 1942 was badly damaged as result of fire in engine room.