Durance-class tanker
The "Durance" class is a series of multi-product replenishment oilers, originally designed and built for service in the French Navy. Besides the five ships built for the French Navy, a sixth was built for the Royal Australian Navy, while the lead ship of the class currently serves with the Argentine Navy. Two ships of a similar but smaller design are in service with the Royal Saudi Navy as the s. In French Navy service the ships were used with the "Force d'action navale" (FAN, "Naval Action Force"). The last three French ships were built to a  modified design with increased space for command operations. The three ships are used as flagships for French naval forces in the Indian Ocean. In 2009, "Somme" repelled an attack by pirates off the coast of Somalia. In 2014, a second French ship was removed from service followed by a third in 2021. In 2019, the Australian ship was taken out of service. French Navy. Design and description. In French service, the class the first two ships were dubbed "Pétrolier Ravitailleur d'Escadre" (PRE, "fleet replenishment oiler"), and the final three, "Bâtiment de commandement et ravitailleur" (BCR, "command and replenishment ship"). In  addition to their role as a fleet tanker, the three dubbed BCR can accommodate an entire general staff and thus supervise naval operations. "Meuse", which had a superstructure that was one deck higher than "Durance", the lead ship of the class and the final three ships of the class, "Var", "Marne" and "Somme" all had superstructures that were extended aft by to accommodate the additional staff requirements. The first two ships carry two cranes abaft the bridge, while the final three only have one positioned along the centreline. The five ships are of similar design but different layouts. "Durance" and  Meuse had a standard displacement of and at full load. "Marne", "Var" and "Somme" have a standard displacement of and at full load. All five ships are long overall and between perpendiculars with a beam of and a draught of empty and at full load. All five vessels are powered by two SEMT Pielstick 16 PC2.5 V 400 diesel engines turning two LIPS controllable pitch propellers rated at . The vessels have a maximum speed of and a range of at . "Durance" was initially equipped with two landing craft for vehicles and personnel. Each ship has two dual solid/liquid underway  transfer stations per side and can replenish two ships per side and one astern. As built, "Durance" had capacity for of fuel oil, of diesel oil, of JP-5 aviation fuel, of distilled water, of provisions, of munitions and of spare parts. "Meuse" had capacity for of fuel oil, of diesel, of JP-5 aviation fuel, of distilled water, of provisions, of munitions and of spare parts. The final three ships of the class differed from "Meuse" by carrying of diesel fuel, of JP-5 aviation fuel, of munitions and of spare parts. These numbers changed with the needs of the fleet. The  Durance-class tankers all mount a flight deck over the stern and a hangar. The ships utilise Aérospatiale Alouette III and Westland Lynx helicopters but are capable of operating larger ones from their flight deck. For defence, "Durance" was armed with twin-mounted Bofors /L60 anti-aircraft (AA) guns. The other four ships initially mounted one Bofors 40 mm/L60 AA guns and two AA guns in a twin turret. They are equipped with two DRBN 34 navigational radars. The armament was later altered for the final four ships by removing the 20 mm guns and adding four M2 Browning machine  guns and three launchers for Simbad Mistral surface-to-air missiles. "Meuse" had only one launcher installed. The ships have a complement of 162 and are capable of accommodating 250 personnel. Ships in class. Five ships of the class were built for the French Navy: Three ships of the class ("Marne", "Somme", and "Var") were fitted out as flagships able to embark an admiral and his staff. The 2013 French White Paper on Defence and National Security planned to replace them with four new double-hulled tankers between 2018 and 2021. However, "Meuse" was decommissioned under budget cuts announced in  October 2014. They will be replaced under the FLOTLOG project by four derivatives of Italy's Vulcano Logistic Support Ship, scheduled to be delivered in 2023, 2025, 2027 and (subject to ratification of the next procurement plan) 2029. Construction and career. The first four tankers were constructed by the Arsenal de Brest at Brest, France between 1973 and 1987. The fifth and final ship was ordered in March 1984 as part of the 1984–1988 plan and was built by Normed at their yard La Seyne, France. The "Durance"-class ships began entering service in 1976 were assigned to the "Force d'action  navale" (FAR, "Naval Action Force"). One of the BCRs ("Var", "Marne" and "Somme") is assigned to Indian Ocean as flagship of the French naval forces in the region. In October 2009, "Somme" repelled an attack by Somali pirates. Royal Australian Navy. The Royal Australian Navy (RAN) ordered one vessel, HMAS "Success", of a modified design in September 1979. A second vessel was planned in 1980, but not optioned. Construction of "Success" was slow and costs increased. The modified "Durance"-class oiler is in length, with a beam of , and a draught of , with a full load displacement of . Propulsion machinery consists  of two SEMT-Pielstick 16 PC2.5 V 400 diesel motors, which supply to the ship's two propeller shafts. Top speed is , and the ship has a range of at . "Success" has a total capacity of 10,200 tonnes of cargo: 8,707 tonnes of diesel fuel, 975 tonnes of aviation fuel, 250 tonnes of munitions (including guided missiles and torpedoes), 116 tonnes of water, 95 tonnes of components and naval stores, and 57 tonnes of food and other consumables. Fuel and liquid stores can be transferred from four points (two on each side), allowing "Success" to replenish two ships simultaneously, while  solid cargo can be moved via vertical replenishment (with a hangar and helipad for a single Sea King, Seahawk, or Squirrel helicopter), or by boat (the RAN LCVP "T 7" is carried on a starboard forward davit). The ship is armed with seven 12.7 mm machine guns, and is fitted for but not with a Mark 15 Phalanx CIWS. The sensor suite includes two Kelvin Hughes Type 100G navigation radars. Ship's company is made up of 25 officers and 212 sailors. Argentine Navy. On 12 July 1999, Argentina acquired "Durance" from the French Navy and renamed the ship  ARA "Patagonia". The ship underwent a refit and has capacity for of fuel oil, 500 t of aviation fuel, 140 t of distilled water, 170 t of provisions, 150 t of munitions and 50 t of spare parts. The ship mounts only two Bofors 40 mm/60 guns and four 12.7 mm machine guns. The ship uses an Alouette III helicopter. The ship entered Argentine Navy service in July 2000. The ship was reported non-operational in 2020. Royal Saudi Navy. In October 1980, Saudi Arabia signed a contract for two replenishment oilers as part of the Sawari I programme. The  Boraida class have a full load displacement of , are long, have a beam of , and a draught of . They use two SEMT Pielstick 14 PC2.5 V 500 diesel engines driving two shafts. They have a top speed of and a range of at 15 knots. They have a complement of 140. The ship can carry of diesel, of aviation fuel, of freshwater, of ammo, and of supplies. The ship is armed by four Breda Bofors 40 mm/70 guns in two twin mounts. They have two CSEE Naja optronic fire control directors for the 40 mm guns. They have an aft  helicopter deck, and can carry either two Eurocopter AS365 Dauphin or one Eurocopter AS332 Super Puma helicopters. Both ships underwent upgrades in 1996–1998. They serve as training ships and depot and maintenance ships.