The ''D'Estienne d'Orves''-class avisos, also known as the A69 type avisos, is a

class Class or The Class may refer to: Common uses not otherwise categorized * Class (biology), a taxonomic rank * Class (knowledge representation), a collection of individuals or objects * Class (philosophy), an analytical concept used differently ...

aviso An ''aviso'' was originally a kind of dispatch boat or "advice boat", carrying orders before the development of effective remote communication. The term, derived from the Portuguese and Spanish word for "advice", "notice" or "warning", an ' ...

s, comparable in size to a light corvette, mainly designed for coastal anti-submarine defence, but are also available for high sea escort missions (notably in support missions with the FOST). Built on a simple and robust design, they have an economical and reliable propulsion system which allows them to be used for overseas presence missions. They were initially intended for use by the

French Navy The French Navy (french: Marine nationale, lit=National Navy), informally , is the maritime arm of the French Armed Forces and one of the five military service branches of France. It is among the largest and most powerful naval forces in th ...

, but have been ordered by the South African Navy (not delivered),

Argentinian Navy The Argentine Navy (ARA; es, Armada de la República Argentina). This forms the basis for the navy's ship prefix "ARA". is the navy of Argentina. It is one of the three branches of the Armed Forces of the Argentine Republic, together with t ...

and

Turkish Navy The Turkish Naval Forces ( tr, ), or Turkish Navy ( tr, ) is the naval warfare service branch of the Turkish Armed Forces. The modern naval traditions and customs of the Turkish Navy can be traced back to 10 July 1920, when it was establi ...

Design and description

The ''D'Estienne d'Orves''-class

s were primarily designed for

anti-submarine warfare Anti-submarine warfare (ASW, or in older form A/S) is a branch of underwater warfare that uses surface warships, aircraft, submarines, or other platforms, to find, track, and deter, damage, or destroy enemy submarines. Such operations are typi ...

(ASW) in coastal areas and colonial coastal patrol. They were ordered as replacements for the E 50 and E 52 type ''

escorteur The French term ''Escorteur'' (Escort Ship) appeared during the Second World War to designate a warship, of a medium or light displacement, whose mission was to protect ocean convoys and naval squadrons from attacks by submarines. This role was ...

s'' of the

. The ships are built austerely and have a

standard displacement The displacement or displacement tonnage of a ship is its weight. As the term indicates, it is measured indirectly, using Archimedes' principle, by first calculating the volume of water displaced by the ship, then converting that value into wei ...

of and at full load. The avisos are long overall and

between perpendiculars Length between perpendiculars (often abbreviated as p/p, p.p., pp, LPP, LBP or Length BPP) is the length of a ship along the summer load line from the forward surface of the stem, or main bow perpendicular member, to the after surface of the stern ...

with a

beam Beam may refer to: Streams of particles or energy * Light beam, or beam of light, a directional projection of light energy ** Laser beam * Particle beam, a stream of charged or neutral particles **Charged particle beam, a spatially localized g ...

of and a draught of . The avisos are propelled by two shafts turning

controllable pitch propeller In marine propulsion, a variable-pitch propeller is a type of propeller with blades that can be rotated around their long axis to change the blade pitch. Reversible propellers—those where the pitch can be set to negative values—can also ...

s powered by two

SEMT Pielstick SEMT Pielstick was a French company that designed and built large diesel engines. Its full name was (Company of Thermal Machines Studies). Founded in 1948, SEMT was bought by MAN Diesel in 2006 During its existence as an independent compa ...

12 PC 2 V400

diesel engine The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-ca ...

s rated at . The two engines are located in a single engine room mounted next to each other and controlled from a room abaft the machinery room. The two diesel engine system was selected due to the preference of endurance over speed. The ''D'Estienne d'Orves'' class has a maximum speed of and a range of at . All ships in the class are fitted with

fin stabiliser A vertical stabilizer or tail fin is the static part of the vertical tail of an aircraft. The term is commonly applied to the assembly of both this fixed surface and one or more movable rudders hinged to it. Their role is to provide control, sta ...

s except for and . The class was intended to be constructed in two groups, the A 69 and A 70 types, with the latter type fitted with two

Exocet The Exocet () is a French-built anti-ship missile whose various versions can be launched from surface vessels, submarines, helicopters and fixed-wing aircraft. Etymology The missile's name was given by M. Guillot, then the technical directo ...

MM38

surface-to-surface missile A surface-to-surface missile (SSM) or ground-to-ground missile (GGM) is a missile designed to be launched from the ground or the sea and strike targets on land or at sea. They may be fired from hand-held or vehicle mounted devices, from fixed ins ...

s (SSM) on either side of the

funnel A funnel is a tube or pipe that is wide at the top and narrow at the bottom, used for guiding liquid or powder into a small opening. Funnels are usually made of stainless steel, aluminium, glass, or plastic. The material used in its construc ...

, but in the end, all ships of the class were fitted with the SSMs. The ships are armed with a CADAM gun turret with Najir fire control system and CMS LYNCEA, a pair of modèle F2 guns and four machine guns. For ASW operations, the ''D'Estienne d'Orves'' class mounts four fixed catapults for L3 or L5 type

torpedo A modern torpedo is an underwater ranged weapon launched above or below the water surface, self-propelled towards a target, and with an explosive warhead designed to detonate either on contact with or in proximity to the target. Historically, s ...

es with no reloads carried and one remote-controlled sextuple rocket launcher, with 30 reloads carried in a magazine located beneath the aft deckhouse. The ''D'Estienne d'Orves'' class is equipped with one air/surface DRBV 51A sentry radar, one DRBC 32E fire control radar one Decca 1226 navigation radar and DUBA 25 hull-mounted sonar. The DUBA 25 is situated in a fixed dome with a retractable transducer, but is designed strictly for use in coastal waters. As countermeasures the avisos have one ARBR 16 radar interceptor, two Dagaie decoy launchers and one

SLQ-25 Nixie The AN/SLQ-25 Nixie and its variants are towed torpedo decoys used on US and allied warships. It consists of a towed decoy device (TB-14A) and a shipboard signal generator. The decoy emits signals to draw a torpedo away from its intended targe ...

countermeasure system, which was fitted in the mid-1980s. The ships have a complement of 90 and have space to accommodate 18 marines.

Modifications

Beyond the Nixie countermeasure system, the funnels aboard the avisos were heightened due to issues with the gases coming from them. had SEMT Pielstick 12 PA 6 BTC diesels with infrared suppression systems installed which led to delays into the vessel's entry into service. In 1993, and had their rocket launchers removed and a Syracuse II satcom terminal installed. Plans were drawn up to give the two ships a

hangar A hangar is a building or structure designed to hold aircraft or spacecraft. Hangars are built of metal, wood, or concrete. The word ''hangar'' comes from Middle French ''hanghart'' ("enclosure near a house"), of Germanic origin, from Frankish ...

and

flight deck The flight deck of an aircraft carrier is the surface from which its aircraft take off and land, essentially a miniature airfield at sea. On smaller naval ships which do not have aviation as a primary mission, the landing area for helicopt ...

for helicopters, but this was abandoned. From 2009, the remaining vessels in French service were reclassified as

offshore patrol vessel A patrol boat (also referred to as a patrol craft, patrol ship, or patrol vessel) is a relatively small naval vessel generally designed for coastal defence, border security, or law enforcement. There are many designs for patrol boats, and the ...

s (OPVs) and, as a result, had their surface-to-surface missiles and heavy anti-submarine weapons removed. All six remaining vessels in the class are planned to be withdrawn from service between 2024 and 2027. Replacement of these vessels in French service is currently planned from about 2025 by a new class of ocean-going patrol vessels.

Ships in the class

South African and Argentine navies

The

Argentine Navy The Argentine Navy (ARA; es, Armada de la República Argentina). This forms the basis for the navy's ship prefix "ARA". is the navy of Argentina. It is one of the three branches of the Armed Forces of the Argentine Republic, together with t ...

also operates three ''D'Estienne d'Orves''-class ships, locally known as the . The first two ships, originally named ''Lieutenant de vaisseau Le Hénaff'' and ''Commandant L'Herminier'' while under construction for the French Navy, were originally acquired by the South African Navy in 1976. In the French Navy they were replaced by new ships with the same names. The two ships were renamed ''Good Hope'' and ''Transvaal'', but due to UN sanctions against

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring count ...

, they were not delivered and were bought by the Argentine Navy on 25 December 1978. They were renamed and . A third ship of the class, , was ordered by Argentina and was delivered in 1981.

Turkish Navy

In October 2000, Turkey acquired six Type A 69 avisos. They were acquired for the

for coastal patrol in order to release more capable Turkish ships for frontline duty. Five of the six vessels were refitted at Brest before transfer.

Citations

References

* * *

External links

globalsecurity.org

Alabordache.com
French Aviso in activity
Alabordache.com
French Aviso disarmed *
Argentine Navy (ARA) official site – class specifications & pictures
{{French Navy Vehicle Corvette classes Frigate classes A69 type avisos Cold War frigates of South Africa Frigates of France Corvettes of the French Navy Ship classes of the French Navy