Capitan O'Brien-class submarine (1928)

Capitan Simpson
Class overview
Name	Capitan O'Brien class
Builders	Vickers
Operators	Chilean Navy
Built	1928–1929
In commission	1929–1958
Completed	3
Retired	3
General characteristics
Type	Submarine
Displacement	Surfaced - 1,540 long tons (1,560 t) Submerged - 2,020 long tons (2,050 t)
Length	260 ft (79 m) pp
Beam	28 ft (8.5 m)
Draught	13 ft 6 in (4.11 m)
Propulsion	2 shaft diesel-electric Vickers diesel engines: 2,750 bhp (2,050 kW) Electric motors: 1,300 hp (970 kW)
Speed	Surfaced: 15 knots (28 km/h; 17 mph) Submerged: 9 knots (17 km/h; 10 mph)
Complement	54
Armament	8 × 21 in (533 mm) torpedo tubes (6 bow, 2 stern 14 torpedoes) 1 × 4.7 in (119 mm)/45 deck gun

The Capitan O'Brien class were three submarines built for the Chilean Navy in the late 1920s. Designed and built in the United Kingdom, they were a modified design of the contemporary British Odin-class submarines. The lead boat, Capitan O'Brien, was launched on 2 October 1928 and the other two on 15 January 1929. All three submarines entered service in 1929. The three vessels remained in service until being discarded in 1957–1958.