CAPTAS-4
Towed array sonar
From Wikipedia, the free encyclopedia
The CAPTAS-4 is a towed array sonar developed by Thales Underwater Systems to equip first-rank surface combatants. Manufactured in Brest, France, it represents the high-end and most powerful system of the company's CAPTAS (Combined Active and Passive Towed Array Sonar) line of products[1] and equips several first-rank warships of the French Navy as well as those of various export customers. A British variant, known as Sonar 2087, equips anti-submarine warfare frigates of the Royal Navy.
Description
The CAPTAS-4 system comprises a UMS-4249 ultra-low-frequency active sonar with four ceramic rings, integrated into a towed variable-immersion body.[2][3] Capable of diving up to 300 meters (980 ft), it covers a very large volume of water over an extremely long range. In addition to the UMS-4249 variable depth sonar, a towed multi-functional linear antenna equipped with hydrophones is used to capture radiated noise and reflected signals: it picks up the feedback of Very Low Frequency (VLF) emissions from the UMS-4249 to locate, classify and track a target, while at the same time providing passive detection that only listens when active sonars are not being used. It is also designed to detect the specific noise of torpedoes, providing an early warning to deploy countermeasures in the event of a submarine attack on the vessel.[2]
The great attribute of the CAPTAS-4, which separates the transmitting and receiving instruments, is its ability to detect submarines at long range (up to 150 km, 93 mi)— allowing the formation of a "safety bubble" around a carrier battle group for example— and instantly determine where the noise is coming from (port or starboard), which is an advantage on the high seas, but also in coastal areas, where the number of signals is very high.[2][3] Thanks to variable immersion, the sonar can be positioned at the best spot to avoid the non-detection troughs that form in the sea as a function of temperature, salinity and water pressure; troughs where submarines can hide.[2]
The CAPTAS-4 equips the French, Italian, Egyptian and Moroccan FREMM frigates, Spanish F110 frigates, and was ultimately selected by the US Navy to equip the Constellation-class frigates after initially favoring a rival system — the DART (Dual-mode Array Transmitter) — whose development had been entrusted by Raytheon but whose performance failed to live up to expectations.[1][4][2][3]
Variants
Sonar 2087
Manufactured at various Thales Underwater Systems' sites in the United Kingdom, the Sonar 2087 is a British variant of the CAPTAS-4. It equips the Royal Navy's Type 23 frigates and will also be integrated on the succeeding Type 26 frigates in construction.
CAPTAS-4 Compact
The CAPTAS-4 compact has been developed to maintain the same detection performance as the CAPTAS-4, while reducing its overall weight by 20% and its footprint by almost 50%.[5][6] This allows medium-size first-rank frigate such as the 4,000-ton French FDI to have the same collaborative anti-submarine warfare capabilities as larger frigates and destroyers. The CAPTAS-4 Compact can also be containerized, making it the only sonar in its class interchangeable from one vessel to another according to Thales.[5] The new system will equip the French FDI frigates expected to enter operational service in 2025 as well as those purchased by Greece.[6]
Operators
Egypt- Three sonars are used by the Egyptian Navy:
- Former French FREMM frigate: [7]
- Former Italian FREMM frigates:[7]
France- 8 sonars are used by the French Navy, 5 additional will enter service:
- French FREMM frigates: [8]
Greece- The Hellenic Navy operates one ship with the SAPTAS-4 sonar, 5 additional are on orders, and more are expected to be ordered.
- Kimon class frigates (the Hellenic FDI frigate variant):
- Kimon
- To be delivered: Nearchos
- To be delivered: Formion
- To be delivered: Themistokles
- Italian FREMM frigates: the Italian Navy will purchase two Italian FDI and are expected to be received in 2029:[9]
Italy- The Italian Navy operates FREMM frigates in multiple variants:
- Carlo Bergamini (to be sold to the Hellenic Navy)
- Virginio Fasan (to be sold to the Hellenic Navy)
- Carlo Margottini
- Carabiniere
- Alpino
- Luigi Rizzo
- Federico Martinengo
- Antonio Marceglia
- Spartaco Schergat
- Emilio Bianchi
- The Italian Navy ordered two FREMM EVO frigates:
- Bersagliere
- Aviere
Morocco- Three sonars are used by the Royal Moroccan Navy:
- Former French FREMM frigate: [7]
Spain- The Spanish Navy ordered 5 frigates of the Bonifaz class (F110 class):[10]
- Bonifaz
- Roger de Lauria
- Menéndez de Avilés
- Luis de Córdova
- Barceló
Potential sales
Belgium- The Belgian Navy is looking for alternatives to the Damen ASW frigates that is having delays, and could order one FDI.[11]
Denmark- Naval Group is pitching its FDI frigate to replace the current frigates in service with the Danish Navy.[12]
- Egypt
- The Egyptian Navy is in talks for the acquisition of the F110 frigates.[13]
- Greece
- The Hellenic Navy is planning to purchase additional new frigates:
- Italy
- The Italian Navy will need at least two additional FREMM EVO to compensate for the two FREMM sold to the Hellenic Navy.[16]
Portugal- The Portuguese Navy selected the FREMM EVO to replace its current frigates. There should be three frigates ordered.[17][15] The contract remains to be signed.
Sweden- The FDI frigate is one of the option retained by Sweden in its selection of the future light frigate (programme Luleå). Four ships are expected to be purchased.[18]
Cancellations
United States- The US Navy ordered 10 Constellation-class frigates, based on the Italian FREMM. They would have been equipped with the CAPTAS-4 sonars.[19][20]
- The programme was cancelled in November 2025. The initial contract was for two sonars with an option for 8 additional ones.[21]
