The ships are crewed by 80 Royal Fleet Auxiliary personnel and 22 Royal Navy personnel.
Wave Knight, large fleet tanker for the UK Royal Navy, was commissioned in March 2003.
RFA Wave Ruler (A390) was commissioned in April 2003.
The Wave Class ships have a maximum speed of 18 knots and a range of over 8,000nm.
The Wave Class role is to provide Royal Navy and allied warships with replacement oil, aviation fuel and stores while at sea.
The ships have a double hull to keep the risk of pollution to a minimum in case of damage.
The vessels can transport up to 16,000t of fuel, 380t of fresh water and 150t of fresh food in eight refrigerated containers.
Launch of Wave Ruler at BAE's Govan yard on the Clyde.

Two large fleet tanker ships, the Wave Class, were built by BAE Systems for the United Kingdom Royal Fleet Auxiliary. The first, RFA Wave Knight (A389), was built at BAE Systems Marine Barrow yard and launched in September 2000.

The second, RFA Wave Ruler (A390), was built at BAE’s Govan yard and launched in February 2001. Wave Knight was commissioned in March 2003 and Wave Ruler in April 2003.

The 30,000t large fleet tankers replace the Olna and Olwen, two 36,000t displacement fast fleet tankers, built at Swan Hunter and Hawthorn Leslie in the 1960s.

The ships are crewed by 80 Royal Fleet Auxiliary personnel and there is also provision for 22 Royal Navy personnel for helicopter and weapons systems operations.

The Royal Fleet Auxiliary Service is the specialist front-line support force for the Royal Navy which replenishes warships at sea with fuel, stores, weapons equipment and munitions.

The fast fleet tankers are able to operate in support of amphibious forces, anti-surface and anti-submarine warfare operations and protection of vital sea areas and shipping.

The tankers support general purpose task groups, the CVSG groups and the Amphibious Task Group and may be deployed away from the United Kingdom for the complete period of its docking cycle, which at present is every 2.5 years. All the maintenance activities are being undertaken in theatre.

In September 2004, RFA Wave Ruler took part in hurricane relief operations in the Caribbean. In August 2008, it was again deployed in the Caribbean to support hurricane relief operations. It supported the hurricane relief efforts in the Cayman Islands in November 2008.

Cargo capacity

The ships have the capacity to transport 616,000m³ of issuable cargo fuel which has a minimum flash point temperature of 60°C. The ships have the capability to deliver fuel through an RAS (replenishment at sea) rig, either port, starboard or astern to other vessels.

“The ships are crewed by 80 Royal Fleet Auxiliary personnel and there is also provision for 22 Royal Navy personnel.”

For amphibious support, the ships can also deliver fuel to pillow tanks or dracones positioned alongside. The RASCON replenishment at sea equipment is supplied by Rolls-Royce (Clarke Chapman). The package of abeam and astern re-fuelling systems includes the RAS system, an ammunition handling crane specially fitted out for abeam re-fuelling, steering gear and rudder packages, thyristor-controlled winch/windlasses and double drum mooring winches.

The ship, equipped with onboard reverse osmosis equipment, has the capacity to manufacture 100³ of potable water per day, and is capable of carrying and delivering 380m³ of potable water. The ships can also transport and deliver other fluids in bulk tanks and in barrels.

The dry cargo capacity is 500m³ together with space, access and power for eight 20ft refrigerated container units.


The ship is armed with two 30mm cannons and can be fitted with two Raytheon Phalanx Mk 15 close-in weapon systems (CIWS). Phalanx has a 20mm/53-calibre six-barrel gun capable of firing 3,000 rounds/min to a target range of 1.5km.

The Block 1B upgrade fires up to 4,500 rounds per minute. The ship will be fitted with air/surface search and navigation radars.


The tanker has one spot flight deck with full hangar facilities to support the Merlin helicopter and is capable of operating a Merlin-sized helicopter in high seas up to Sea State 6.

Navigation and communications

The ship is equipped with an Integrated Bridge Navigation System (IBNS), supplied by Kelvin Hughes.

“In September 2004 and August 2008, RFA Wave Ruler took part in hurricane relief operations in the Caribbean.”

The IBNS has a Digital Programmable Primary Internal Communications System (DPPICS) and an Integrated Platform Management System (IPMS) including: machinery control and surveillance, damage surveillance and control, electrical power control and management and refuelling at Sea/Cargo Ballast Control (RASCON) functions.

The communications suite covers a very wide band, MF/HF and V/UHF, with external military and civil communications and a civil satellite communications system (SATCOM).


The ship’s diesel-electric propulsion system is based on a 14MW ALSTOM variable speed, bi-directional AC electric drive motor, controlled by a CEGELEC synchro-converter.

Four generators, supplied by ALSTOM and each providing 4.69MW, are driven by Wartsila V12 VASA32 (Lox Nox) diesel engines. The engines drive a single fixed pitch propeller and shaft.

The ship is equipped with an 18t thrust electric bow thruster and a 12t thrust electric stern thruster. The ship’s auxiliary diesel engine provides 1.6MW.

The ships propulsion system provides a maximum speed of 18 knots and a minimum sustainable speed of 4 knots for up to 12 hours, without detriment to the machinery. The range exceeds 8,000 nautical miles.