View source for River-class submarine

{{Short description|Type of British submarines in service during WWII}}
{{For|other naval ship classes of the same name|River class (disambiguation)}}
{{Use dmy dates|date=January 2018}}
{{Use British English|date=January 2018}}
{|{{Infobox ship begin}}
{{Infobox ship image
| Ship image = HMS Thames.jpg
| Ship caption = HMS ''Thames''
}}
{{Infobox ship class overview
| Name = ''River''-class
| Builders = Vickers-Armstrong
| Operators = {{navy|United Kingdom}}
| Class before = [[British S-class submarine (1931)|S class]]
| Class after = {{sclass|Grampus|submarine|4}}
| Subclasses = 
| Cost = circa £500,000 (in 1931-1933)
| Built range = 1931-1934
| In service range = 1934-1945
| In commission range = 1934-1945
| Total ships planned = 20
| Total ships completed = 3
| Total ships cancelled = 17
| Total ships active = 
| Total ships laid up = 
| Total ships lost = 1
| Total ships retired = 2
| Total ships preserved = 
}}
{{Infobox ship characteristics
| Hide Header
| Header caption = 
| Ship type = [[Submarine]]
| Ship ordered = 1931
| Ship displacement = *2,206 tons surfaced (''Thames'' 2,165 tons)
*2,723 tons submerged (''Thames'' 2,680 tons)
| Ship length = {{convert|345|ft|m|abbr=on}}
| Ship beam = {{convert|28|ft|3|in|abbr=on}}
| Ship height = 
| Ship draught = {{convert|4.85|m|ftin|abbr=on|order=flip}}
| Ship draft = 
| Ship power = 
| Ship propulsion = *2 shaft diesel electric
*2 supercharged diesels {{convert|10,000|hp|kW|abbr=on}} max
*2 electric motors {{convert|2,500|hp|kW|abbr=on}}
| Ship speed = *{{convert|22|kn|km/h|0}} surfaced
*{{convert|10|kn|km/h|0}} submerged
| Ship range = {{convert|12000|nmi|abbr=on|lk=on}} at {{convert|12|kn|abbr=on}} surfaced
| Ship fuel load = <!--"Ship fuel load" seems to not exist and "tons" is not a valid unit: {{convert|210|tons|imp gal|abbr=on}} -->
| Ship endurance = 
| Ship complement = 61
| Ship sensors = [[ASDIC]]
| Ship EW =
| Ship armament = *6 × [[British 21 inch torpedo|21-inch (533 mm)]] [[torpedo tube]]s (bow)
*1 × [[QF 4 inch naval gun Mk IV, XII, XXII|QF {{convert|4|in|mm|adj=on|sigfig=4}} Mk XII deck gun]]
| Ship aircraft = none
| Ship aircraft facilities = 
| Ship notes = Last fleet submarine design adopted by the Royal Navy
| Ship test depth = *{{convert|300|ft|m}}, entered into records as max depth
}}
|}

The '''River class''', or '''''Thames'' class''', were a class of [[submarine]]s built for the [[Royal Navy]]. Operating during the [[Second World War]], the three boats of the class comprised {{HMS|Thames|N71|2}}, {{HMS|Severn|N57|2}} and {{HMS|Clyde|N12|2}}. All the submarines were named after rivers in the [[United Kingdom]]. One was lost during the war and the rest taken out of service following it.

==Design==
The River class was the last attempt by the [[British Admiralty|Admiralty]] to produce "[[fleet submarine]]s", submarines fast enough to operate as part of a fleet, which at the time meant being able to manage somewhere around {{convert|20|kn|km/h|0}} while surfaced. The previous attempts had been the steam powered [[British K-class submarine|K-class submarines]] and the large {{convert|12|in|mm|0|adj=on}} gunned [[British M-class submarine|M-class submarines]]. The M class were K-class [[Hull (watercraft)|hulls]] re-engined with diesels and modified to take a single {{convert|12|in|mm|abbr=on|0}} naval gun directly forward of the [[conning tower]].

A design was drawn up in the late 1920s and three vessels were built by [[Vickers]] in Barrow: ''Thames'' in 1932, and ''Severn'' and ''Clyde'' in 1935. The latter two were a little larger than ''Thames''. Initially 20 were planned, but changes in thinking and cost-cuts limited the building to just the three.

The design compromised on diving depth to keep weight down and speed up. They had a safe diving depth of some {{convert|300|ft|m|-1}} compared to the {{sclass|Odin|submarine|4}} before them which had managed {{convert|500|ft|m|-1}}. They were powered by two [[diesel engine]]s delivering {{convert|8,000|bhp|kW|lk=in|abbr=on}}. Two [[Ricardo plc|Ricardo]] engines drove generators that supercharged the diesels up to {{convert|10,000|bhp|kW|abbr=on}}. This gave them a surface speed of {{convert|22|kn|km/h|0}}. A rather unfortunate fault with the River-class was a tendency for engine trouble after several long journeys. Another alarming fault, although this was confined to ''Clyde'' was the hydroplanes failing, causing the submarine to bottom. This would put a great stress on the hull of the submarine, as it was of riveted construction, rather than the welded construction of other British submarines.

==Operational history==
During the Second World War, they initially operated in the [[North Sea]] and [[Mediterranean]], then moved to the Far East in the latter stages.

''Clyde'' and ''Severn'' set sail from Gibraltar heading to take up station in Freetown on 31 August 1939, just four days before the outbreak of hostilities. On their arrival, they joined South Atlantic Command and were tasked with convoy defence duties.<ref>[https://uboat.net/allies/warships/ship/3411.html HMS Clyde Service History for Second World War]</ref> They arrived on September 7, with ''Clyde'' departing on her first war patrol the following day.

''Thames'' was lost off [[Norway]] on 23 September 1940 during an operation to sink the German Battlecruiser ''Gneisenau''. It failed to do this, but sank the escorting torpedo boat ''Luchs''.<ref>[https://uboat.net/allies/warships/ship/3409.html HMS Thames Service History for Second World War]</ref> The wreck of the ''Thames'' is yet to be found. When it is discovered, it is highly likely that it is to be left alone, because like all ships lost in wartime, it is considered to be a war grave.

''Clyde'' was used on six occasions to deliver supplies to the besieged island of [[Malta]] in September 1941. ''Severn'' was used as part of the escort for Convoy SL16F in January 1940, along with the Armed Merchant Cruiser HMS Cheshire and the destroyers HMS Hardy and HMS Hostile. Convoy duty was not something that was alien to ''Severn'' and ''Clyde'', as they would carry out this duty on a regular basis due to their long range. ''Clyde'' and ''Severn'' would both go through an extensive refit in the USA

''Severn'' had the most colourful service out of all three. It would be used in the aftermath of the [[Battle of the River Plate]] to hunt for German Surface Raiders and their support ships. April 5, 1940 would see Severn join the northbound convoy FN139. It would also be put on standby for potential involvement in the hunt for the Bismarck, but the Bismarck was sunk before the Severn was called into action. It would be used for part of [[Operation Hawthorn]] during June - July 1943. ''Severn'' and ''Clyde'', whether it was by choice or accident, would often be stationed together. ''Severn'' and ''Clyde'' were in service in the Far East (operating out of [[Trincomalee]]) when they were taken out of service - ''Severn'' in December 1944 and ''Clyde'' in July 1945. Both ships were believed to have been scrapped by the end of 1946.

==Boats==

* {{HMS|Thames|N71}} - accounted for 1 enemy vessel
* {{HMS|Severn|N57}} - accounted for 4 enemy vessels
* {{HMS|Clyde|N12}} - accounted for 6 enemy vessels

==References==
<references />

==Bibliography==
* {{cite journal|last1=Caruana|first1=Joseph|year=2012 |title=Emergency Victualling of Malta During WWII|journal=Warship International|volume=LXIX |issue=4 |pages=357–364 |issn=0043-0374}}
* Conway's All the World's Fighting Ships 1922–1946
* D.K. Brown - Nelson to Vanguard, Chatham Maritime Press {{ISBN|1-86176-136-8}}
* {{cite book|title=Jane's Fighting Ships of World War II|year=1998 |page=63 |isbn=1-85501-994-9}}

==External links==
{{Commons category|River class submarines}}
* [http://rnsubs.co.uk/boats/subs/river-class.html - RN Subs 1929 - 1945: River Class]
* [http://uboat.net/allies/warships/class.html?ID=48 - page from Uboat.net]

{{River class submarine}}
{{WWII British ships}}

[[Category:River-class submarines| ]]
[[Category:Submarine classes]]