NAVYPEDIA

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Severn 1939

Ships

Name	No	Yard No	Builder	Laid down	Launched	Comp	Fate
Thames	F71 - N71		Vickers-Armstrong, Barrow	1.1931	26.1.1932	9.1932	sunk 23.7.1940
Severn	F57 - N57		Vickers-Armstrong, Barrow	3/1933	16.1.1934	1.1935	BU 7?/1946
Clyde	F12 - N12		Vickers-Armstrong, Barrow	5/1933	15.3.1934	4/1935	BU 7.1946

Technical data

Max speed, kts, kn	Thames: 22.5 / 10 others: 22 / 10
Displacement standard, t	Thames: 1830 others: 1850
Displacement normal, t	Thames: 2165 / 2680 others: 2206 / 2723
Length, m	105.2
Breadth, m	8.62
Draught, m	Thames: 4.76 others: 4.85
No of shafts	2
Machinery	2 Admiralty supercharged diesels / 2 electric motors
Power, h. p.	10000 / 2500
Fuel, t	Thames: diesel oil 216 - 224 others: diesel oil 202
Endurance, nm(kts)	6260(12.4) / 115(4)
Armament	Thames: 1 x 1 - 120/45 QF Mk IX, 2 x 1 - 12.7/62, 6 - 533 TT (bow; 12) others: 1 x 1 - 102/40 QF Mk XII, 2 x 1 - 12.7/62, 6 - 533 TT (bow; 12)
Electronic equipment	type 120A sonar
Complement	61
Diving depth operational, m	60

Standard scale images

Graphics

Project history

Fleet submarines, designed for replacement of out-of-date "K" class. For achievement of the 22kts speed (speed of battleships), special 5000hp diesels were designed. Big size of the latter have compelled to refuse from stern TTs originally provided by the specification. In addition to main diesels 2 more 400hp diesel-generators for battery charging were installed. Double-hulled submarines, operational diving depth was 60m, maximal 95m. Fuel tanks, arranged out of a pressure hull, were welded.

Lead Thames was built under the 1929 Programme. It was originally supposed to built large series of similar ships, however Admiralty had soon refused the concept of fleet submarine and only three were completed instead of 20 planned. Two serial-built boats, Clyde (1931 Programme) and Severn (1932 Programme), differed from the lead ship a little: so, ballast tanks have been taken out in a hull superstructure to improve stability, and there was 102mm gun instead of 120mm.

Modernizations

1935, Thames: - 1 x 1 - 120/45; + 1 x 1 - 102/40 QF Mk XII

1942 - 1943, Severn, Clyde: + 1 x 1 - 20/70 Oerlikon Mk II/IV, they also received ability to carry 12 M2 mines instead of torpedoes, + type 286W or type 291W radar

1/1946, Severn, Clyde: 1 x 1 - 102/40 S Mk I, 1 x 1 - 20/70 Mk IIA S/M, 6 - 533 TT, type 286W or type 291W radar, type 120A sonar

Naval service

Thames was lost on a mine off Norwegian coast 3.8.1940.