Tide-class tanker

Tiderace in August 2017
Class overview
Name	Tide class
Builders	DSME
Operators	Royal Fleet Auxiliary
Preceded by	Leaf class and Rover class
Cost	£452 million (eventually £550 million) for 4 RFA vessels (hull build only) £137.5 million per RFA unit final (hull build only) NOK 1.32 billion for HNoMS Maud (FY 2013)
In service	2017
Planned	4 (RFA), 1 (Norway)
Completed	4 (RFA), 1 (Norway)
Active	3 (RFA), 1 (Norway)
Laid up	1 (RFA) in extended readiness (uncrewed reserve)
General characteristics [1]
Type	Fast fleet tanker
Displacement	39,000 t (38,000 long tons; 43,000 short tons)
Length	200.9 m (659 ft 1 in)
Beam	28.6 m (93 ft 10 in)[2]
Draft	10 m (32 ft 10 in)
Propulsion	Combined diesel-electric or diesel (CODELOD)
Speed	20 knots (37 km/h; 23 mph)[3]
Range	18,200 nautical miles (33,700 km; 20,900 mi)
Capacity	Tanks for diesel oil, aviation fuel (19,000 m³) and fresh water (1,400 m³) Lubrication oil stored in drums Stowage for up to 8 ft × 20 ft containers
Complement	63 plus 46 non-crew embarked persons (Royal Marines, flight crew, trainees)
Sensors and processing systems	Kelvin Hughes Integrated Bridge System Servowatch IPMS System 3 × SharpEye radar[4]
Armament	2 × Phalanx CIWS (fitted for, depending on deployment)[5] 2 × DS30B Mk 1 30 mm guns (fitted for, depending on deployment)[6]
Aircraft carried	1 × Wildcat or AgustaWestland Merlin
Aviation facilities	Enclosed Merlin-capable hangar Large Chinook-capable flight deck

The Tide-class tanker (formerly the Military Afloat Reach and Sustainability (MARS) project) is a class of four fast fleet tankers that entered service with the British Royal Fleet Auxiliary from 2017. The 37,000 t ships provide fuel, food, fresh water, ammunition and other supplies to Royal Navy vessels around the world. Norway ordered a similar 26,000 t version with a 48-bed hospital and greater solid stores capacity, but reduced liquid capacity; it was delivered in November 2018 as HNoMS Maud two years after originally planned. The two classes are very similar but are not directly comparable due to large variance in capabilities delivered.

The two variants are both based on the AEGIR design from Britain's BMT Defence Services but were built by Daewoo in South Korea with final outfitting in the UK and Norway respectively. Britain ordered four ships in February 2012 at a cost of £452m for the building of the hulls, but in the end became £550m. The Royal Norwegian Navy ordered HNoMS Maud in June 2013 for NOK1,320m (~£140m).