River-class offshore patrol vessel

Batch 1 River-class vessels HMS Severn, HMS Tyne and HMS Mersey exercising off the coast of Cornwall, 2012
Class overview
Name	River class
Builders	Batch 1: Vosper Thornycroft[nb 1] Batch 2: BAE Systems Maritime – Naval Ships
Operators	Royal Navy  Brazilian Navy  Royal Thai Navy  Royal Bahrain Naval Force
Preceded by	Castle class
Subclasses	Krabi-class patrol vessel Amazonas-class corvette
Built	2001–present
In commission	2003–present
Planned	14
Completed	14
Active	8 (Royal Navy) 3 (Brazilian Navy) 2 (Royal Thai Navy) 1 (Royal Bahrain Naval Force)
General characteristics
Type	Offshore patrol vessel
Displacement	Batch 1: 1,700 t (1,700 long tons)[2][1] Batch 2: 2,000 t (2,000 long tons)[5][4]
Length	Batch 1: 79.5 m (260 ft 10 in)[1][3] Batch 2: 90.5 m (296 ft 11 in)[2][5][4]
Beam	Batch 1: 13.5 m (44 ft 3 in)[2][1] Batch 2: 13.5 m (44 ft 3 in)[2][5]
Draught	Batch 1: 3.8 m (12 ft 6 in)[1]
Propulsion	Batch 1: 2 × Ruston 12R270 diesel engines, 8,250 kW (11,060 hp), 2 shafts 2 × controllable-pitch propellers Batch 2: 2 × MAN 16V28/33D diesel engines, 14,700 kW (19,700 hp), 2 shafts 2 × controllable-pitch propellers
Speed	Batch 1: 20 knots (37 km/h; 23 mph)[2][1][3] Batch 2: 25 knots (46 km/h; 29 mph)[2][5][4]
Range	Batch 1 & 2: 5,500 nmi (10,200 km; 6,300 mi)[2][3][4]
Endurance	Batch 1: 21 days[2] Batch 2: 35 days[2][5][4]
Boats & landing craft carried	Two Pacific 24 RIBs;[4] Batch 2: Small Unmanned underwater vehicles may be embarked for mine countermeasures[18][19][20]
Troops	Batch 1: c. 18[2][1][8] Batch 2: up to 50[2][4]
Complement	Batch 1: 28-30[1][8] Batch 2: 34-45[9][8][10][11]
Sensors and processing systems	Batch 2: Kelvin Hughes Ltd SharpEye navigation radar[12] Terma Scanter 4100 2D radar[13] BAE CMS-1[4][14] Shared Infrastructure operating system[4]
Armament	Batch 1:[1] 1 × Oerlikon 20 mm cannon 2 × General purpose machine guns[15] Batch 2:[5][4] 1 × Bushmaster 30 mm cannon 2 × Miniguns (replaced by Browning .50 caliber heavy machine guns as of 2023)[16] 2 × general purpose machine guns[15]
Aviation facilities	Batch 2: Merlin-capable flight deck;[5][4] small UAVs may be embarked[6][7]
Notes	Batch 1: 25-tonne crane[17] Batch 2: 16-tonne crane[4]

The River class is a class of offshore patrol vessels built primarily for the Royal Navy of the United Kingdom. A total of nine were built for the Royal Navy (RN), four Batch 1 and five Batch 2. One Batch 1 (HMS Clyde), which was the Falklands guard ship, was decommissioned and transferred at the end of its lease to the Royal Bahrain Naval Force.

The three remaining Batch 1 ships perform fisheries security and border patrol tasks in UK waters. The five new Batch 2 ships provide overseas forward presence, performing maritime security duties and disaster relief operations, often supported by a Royal Fleet Auxiliary vessel.

The Batch 1 ships of the class replaced the seven ships of the Island class and the two Castle-class patrol vessels.

HTMS Krabi was the first of two ships adapting the River design for the Royal Thai Navy and built in Thailand. The three ships of the Amazonas-class offshore patrol vessel in service with the Brazilian Navy were developed from the Batch 1 River-class design, and the Royal Navy's Batch 2 ships were in turn based upon the Amazonas design.

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