HMCS Waskesiu
Class overview
Operators	World War II:  Royal Navy  Royal Australian Navy  Royal Canadian Navy  Free French Naval Forces  Royal Netherlands Navy  South African Navy  United States Navy Post–World War II  Argentine Navy  Royal Ceylon Navy; (later, the Sri Lanka Navy)  Chilean Navy  Royal Danish Navy  Dominican Navy  Egyptian Navy  Indian Navy  Israeli Navy  Royal Malaysian Navy  Royal Moroccan Navy  Myanmar Navy  Royal New Zealand Navy  Royal Norwegian Navy  Pakistan Navy  Peruvian Navy  Portuguese Navy
Succeeded by	Loch class
Subclasses	RN group I, RN group II, RAN group I, RAN group II, RCN group
In commission	1942
Planned	30
Completed	151
Cancelled	2
Active	1 as training ship 1 converted to yacht
Lost	5World War II 2Suez Crisis 10 expended
Preserved	4
General characteristics
General characteristics (RN group II)
Range	646long tons (656 t) oil fuel; 7,500 nmi (13,890 km; 8,631 mi) at 15 knots (27.8 km/h; 17.3 mph)
Notes	Other data per RN group I
General characteristics (RCN group)
Displacement	1,445 long tons (1,468 t) 2,110 long tons (2,144 t) (deep load)
Range	646 long tons (656 t) oil fuel; 7,500 nmi (13,890 km; 8,631 mi) at 15 knots (27.8 km/h; 17.3 mph)
Complement	157
Armament	2 ×QF 4-inch (101.6 mm) XVI guns on twin mountHA/LA Mk.XIX 1 ×QF 12-pdr 12 cwt (3-inch (76.20 mm)) Mk. V gun on mounting HA/LA Mk.IX (not all ships) 8 × 20 mm QF Oerlikon A/A on twin mounts Mk.V 1 × Hedgehog 24 spigot A/S projector Up to 150depth charges
Notes	Other data per RN group I
General characteristics (RAN group I)
Displacement	1,420 long tons (1,443 t) 2,020 long tons (2,052 t) (deep load)
Range	500long tons (508 t) oil fuel; 5,180 nmi (9,593 km; 5,961 mi) at 12 knots (22.2 km/h; 13.8 mph)
Complement	140
Armament	2 ×QF 4-inch (101.6 mm) Mk.XVI guns, single mounts HA/LA Mk.XX 8 × QF 20 mm Oerlikon, single mounts Mk.III,later; 3 ×QF 40 mm Bofors, single mounts Mk.VII 4 × QF 20 mm Oerlikon, twin mounts Mk.V 1 × Hedgehog 24 spigot A/S projector Up to 50depth charges
Notes	Other data per RN group I
General characteristics (RAN group II)
Displacement	1,545 long tons (1,570 t) 2,185 long tons (2,220 t)
Complement	177
Sensors & processing systems	SC radar
Armament	4 ×QF 4-inch (101.6 mm) Mk.XVI guns, twin mounts HA/LA Mk.XIX 3 ×QF 40 mm Bofors, single mounts Mk.VII 4 × QF 20 mm Oerlikon, twin mounts Mk.V 1 × Hedgehog 24 spigot A/S projector Up to 50depth charges
Notes	Other data per RAN group I

TheRiver class was aclass of 151frigates launched between 1941 and 1944 for use asanti-submarineconvoy escorts in theNorth Atlantic. The majority served with theRoyal Navy andRoyal Canadian Navy (RCN), with some serving in the otherAllied navies: theRoyal Australian Navy (RAN), theFree French Naval Forces, theRoyal Netherlands Navy and, post-war, theSouth African Navy.

The Royal Navy placed the first orders in 1940, and the vessels were named after rivers in theUnited Kingdom, giving the name to the class. In Canada, they were called after towns and cities, although they retained the same designation.^[1] Originally called a "twin-screw corvette", the name "frigate" was suggested by Vice-AdmiralPercy W. Nelles of the Royal Canadian Navy.^[2] Canada originally ordered the construction of 33 frigates in October 1941.^[1][2] The design was too big for the locks on theLachine Canal so it was not built by the shipyards on theGreat Lakes and therefore all the frigates built in Canada were built in dockyards along the West Coast or along theSt. Lawrence River below Montreal.^[2] In all, Canada ordered the construction of 70 frigates, including ten for the Royal Navy, which transferred two (USS Asheville andUSS Natchez) to theUnited States Navy.^[1] These served as the basis of the US NavyTacoma class frigate series. Twelve were built in Australia for the RAN (four to a modified design).

AfterWorld War II, they found employment in many other navies the world over; several RCN ships were sunk asbreakwaters. One,HMCS Stormont, was purchased byAristotle Onassis and converted into theluxury yachtChristina O.

The River-class ships were designed by naval engineerWilliam Reed, ofSmith's Dock Company of South Bank-on-Tees, to have the endurance and anti-submarine capabilities of theBlack Swan-classsloops, while being quick and cheap to build in civil dockyards using the machinery (e.g.reciprocating steam engines instead of turbines) and construction techniques pioneered in the building of theFlower-classcorvettes. Its purpose was to improve on the convoy escort classes in service with theRoyal Navy, including the Flower class.

Improvements over the corvette design included markedly better accommodation. The twin engines gave only 3 knots (3 mph; 6 km/h) more speed but extended the range of the ship to nearly double that of a corvette to 7,200 nmi (13,300 km; 8,300 mi) at 12 kn (22 km/h; 14 mph).^[2] Among other lessons applied to the design was armament better designed to combatU-boats, including a twin 4 in (100 mm) mount forward and 12-pounder [76 millimetres (3.0 in)]aft.^[1] Fifteen Canadian frigates were initially fitted with one 4 in (100 mm) gun forward but with the exception ofHMCS Valleyfield, they were all eventually upgraded to the twin mount.^[2] For underwater targets, it was equipped with aHedgehog anti-submarine mortar,depth charge rails and four side-mounted throwers aft for a 10-charge pattern (some had 8 throwers for a 14-charge pattern for a brief period until this was abandoned).^[1]

River-class frigates were the first Royal Canadian Navy warships to carry the 147B Sword horizontal fan-beam active sonar transmitter, in addition to the regularASDIC. This allowed the ship to maintain contact with targets even while firing, unless a target was struck. Better radar and radio direction-finding equipment enhanced the RCN's ability to locate and track enemy submarines over previous classes.^[1] The River-class design was used as the basis for theUnited States NavyTacoma class (which served in the Royal Navy as theColony class); the hull design was later elaborated into theLoch class and subsequently theBay class.

Two hundred and forty-three frigates were built in Britain, Canada and Australia for seven navies during World War II.

On display inBrisbane,Australia isHMAS Diamantina, the last complete River-class frigate, preserved at theQueensland Maritime Museum.

HMCS Stormont served as a convoy escort during theBattle of the Atlantic and was present at theD-Day landings.^[3] In 1947, Greek shipownerAristotle Onassis purchased her for scrap value and converted her into a luxurioussuperyacht namedChristina O, after hisdaughter. The vessel is now owned by John Paul Nicolaou, who lets the yacht for elite charters and cruises.

SLNS Gajabahu, formerly HMCSHallowell served as a convoy escort during World War II and later transferred to the Israeli Navy and then the Royal Ceylon Navy, which later became the Sri Lankan Navy. She was withdrawn from active duty in 1980 and is now used as a training ship by Sri Lanka.

UBS Mayu, formerlyHMS Fal, is preserved inSeikkyi,Myanmar.

"HMSSaltash" was a fictional River-class frigate inNicholas Monsarrat's 1951 bookThe Cruel Sea. (In the 1953Jack Hawkinsfilm version she is called "HMSSaltash Castle", and was played by the corvetteHMS Portchester Castle.)

HMCS New Glasgow played the fictional frigate "HMSRockhampton" in the 1955John Wayne filmThe Sea Chase. (She had just been recommissioned as aPrestonian class upgrade of the Canadian River-class frigate, after ten years in reserve.)

"HMSNairn" was a fictional River-class frigate inAlistair MacLean's 1955 bookHMS Ulysses.

• List of Escorteurs of the French Navy
• List of patrol vessels of the United States Navy

• Colledge, J. J.; Warlow, Ben (2006) [1969].Ships of the Royal Navy: The Complete Record of All Fighting Ships of the Royal Navy from the 15th Century to the Present (Rev. ed.). London: Chatham Publishing.ISBN 978-1-86176-281-8.OCLC 67375475.
• Lavery, Brian (2006).River-Class Frigates and the Battle of the Atlantic: A Technical and Social History. London: National Maritime Museum.ISBN 0-948065-73-7.
• Lenton, H. T. (1998).British & Empire Warships of the Second World War. Annapolis, Maryland: Naval Institute Press.ISBN 1-55750-048-7.
• Marriott, Leo (1983).Royal Navy Frigates 1945–1983. Ian Allan.ISBN 0-7110-1322-5.

Wikimedia Commons has media related toRiver class frigates.

• Convoy escort movements for River-class frigates

• River-class frigates
• Battle of the Atlantic
• Frigate classes
• North Atlantic convoys of World War II
• Ship classes of the French Navy
• Ship classes of the Royal Navy
• World War II frigates of the United Kingdom

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