Modernization of Turkish Submarines

In a significant development for the Turkish Navy, the inventory of Preveze class submarines is undergoing a half-life modernization project.

The Preveze Class Submarine Half-Life Modernization Project, initiated by SSB in 2016 covers the submarines TCG Preveze, TCG Sakarya, TCG 18 Mart, and TCG Anafartalar was launched and formally approved in 2017. On 8 February 2019, the Turkish defense acquisition agency SSB awarded a contract to STM, Havelsan, Aselsan, and Asfat partnership.

The Turkish Naval Forces operate eight Type 209/1400 class submarines. The first batch of four submarines was commissioned between 1994 and 1998. These four submarines are also known as Preveze class and have differences in equipment configurations from the later four. The mid-life modernization program covers both replacements of the existing ISUS combat management system by the MÜREN-Preveze combat management system developed by TÜBİTAK BİLGEM and the replacement of the older sensors and hardware by contemporary ones made by local companies. Both projects are separately contracted.

The main components to be replaced, overhauled, or updated during the MLU are the inertial navigation system, salinity-depth-density measurement system, floating antenna, telescopic SATCOM antenna, attack and navigation periscope, emergency communications system, cold water system and static converter, and air filtration system.

In February 2022, STM successfully completed the sea acceptance trials of the inertial navigation, salinity-depth-density measurement, cold-water systems, and static inverters, of the Preveze class mid-life upgrade project. Furthermore, the acceptance activities for these systems were concluded on March 2, 2023.

As part of the Preveze MLU, a  second contract for the installation of the MÜREN-Preveze combat management system was signed between SSB and  TÜBİTAK BİLGEM in August 2017. The first submarine integrated with the MÜREN-Preveze CMS is the submarine TCG Preveze. According to TÜBİTAK BİLGEM, the CMS can integrate data from 20 different sensors and navigation systems and can manage sonar signal processing, target movement analysis, and ship navigation. Furthermore, the CMS will be able to launch and control modern heavy-class torpedoes including the first domestic heavy-class torpedo Akya, developed by Roketsan.

In 2020 a shore-based development laboratory for the MÜREN CMS was opened inside the Turkish Navy’s research and development facility ARMERKOM. In 2021 the CMS and its consoles were integrated onboard the Preveze. The harbor acceptance tests were completed in late 2021. The sea acceptance tests are continuing.

In another significant development, STM has been assigned the platform integration responsibility for the Advent-Müren Combat Management System on the Gür class submarines. Through a contract signed between TÜBİTAK Bilgem and STM, the project aims to enhance the combat capabilities of these submarines. The Gür class submarines will be equipped with the national torpedo firing capability, enhancing their role in the defense. The modernization of the combat management system with national capabilities highlights Turkey’s commitment to strengthening its maritime presence.

The ongoing modernization efforts for Turkish submarines demonstrate the nation’s commitment to advancing its defense industry and embracing national technological advancements. Turkish local companies like STM play a pivotal role in supplying critical systems and undertaking platform integration highlighting their expertise in submarine engineering. As Turkey strives to increase its naval deterrence and bolster its maritime strength, these projects will undoubtedly contribute to the country’s security and the capabilities of the Turkish Naval Forces Command.

New ESM Sensor For Burak Class Corvettes

The above photo, taken in March 2018 shows TCG Bartın with her original ESM sensor on top of her mast. The below photo, taken in January 2023, shows TCG Bartın with her new ESM sensor.

The above photo, taken in March 2018 shows TCG Bartın with her original ESM sensor on top of her mast. The below photo, taken in January 2023, shows TCG Bartın with her new ESM sensor.

TCG Bartın was spotted fitted with a new set of electronic support measures systems this week when this ship made a port visit in Istanbul.

This was the first time that the Burak, (ex-Aviso) class corvettes fitted with this new and unnamed system. These ships were procured from the French Navy in the early 2000s.

A close-up view of the new ESM system.

A close-up view of the new ESM system.

While there is no publicly available information regarding this new ESM system, it is safe to assume that it was a labor of a collaboration between the Turkish Naval Forces and Aselsan. This outside sensor does not look like the one installed on board Ada and Meko 200 T1 class warships. Thus it must be specially designed to fit on the mast of Burak class corvettes.

This is not the first time that Aselsan has replaced a legacy ESM system on board a Turkish warship. In 2017, Aselsan started to replace the Signaal Rapids/Ramses ESM suit with a locally made one. That system was made of a new ESM sensor, dedicated or shared multi-function operator consoles, and a decoy launching system.

The new system installed on board TCG Bartın, has a new ESM sensor, as it was recognizable from the outside. I believe there will be a new dedicated or shared multi-function operator console inside the combat management center to display the data received by the sensors. To shorten the reaction time the decoy launchers are probably connected to the new ESM suite.

Existing Aselsan ESM systems have the capability of detecting, intercepting, identifying, classifying, tracking,  direction finding, localizing, platform correlating, and recording electromagnetic emissions.

This new system will without a doubt increase the ship’s situational awareness and enable the crew to make more informed decisions.

Electronic Warfare Exercise With Unmanned Vessels

This week, Turkish Naval Forces conducted an electronic warfare exercise off the coast of Antalya.

The embedded short video shows ULAQ unmanned surface vessel with an EW suite and antenna. This version of ULAQ was made public when it was shown to the members of the Ankara Military Attache Corps.

The details of the new configuration have not been shared with the public. However, on the panel The Future of Unmanned Naval Systems and Turkey’s Potential held during the SAHA Expo last week, it was reviled that the Sefine Shipyard – Aselsan joint venture the Merlin USV was also in Antalya.

The Merlin took part in REPMUS 22 and Dynamic Messenger 22 exercises held at the Maritime Operational Experimentation Center (CEOM) in Troia, Portugal.

Besides the USV, there was one Yavuz class frigate, one Ada class corvette, and one Kılıç class fast attack craft participating in the exercise.

The presence of two especially for electronic warfare configured unmanned surface vessel indicates that the Turkish Navy is spending time learning the potential of these vessels closely and developing concepts to use these vessels in action.

One Ada class corvette in the background and one Yavuz class frigate off the coast of Antalya during the electronic warfare exercise. Photo: Mert Şekersoy. Used with permission.

Testing Of DÜFAS Sonar System Has Started

TCG Sokullu Mehmet Paşa. Note the Gökdeniz CIWS turret has been replaced with other equipment. Photo: Oğuz Eroğuz.

The detail equipment installed on board of TCG Sokullu Mehmet Paşa. Photo: Oğuz Eroğuz.

The detail equipment installed on board of TCG Sokullu Mehmet Paşa. Photo: Oğuz Eroğuz.

The Turkish Navy started to test a new towed sonar array on board of TCG Sokullu Mehmet Paşa.

Previously the Rhein class auxiliary ship was used as the test bed for the Aselsan made Gökdeniz CIWS system. Photos, recently taken show that the Gökdeniz CIWS turret was removed from the ship. The aft of the ship is now occupied with a metal shelter, one large cable spool a winch and some davits like metal construction.

It was previously reported that the testing of the DÜFAS towed array system would commence in 2022. While the initial reporting mentions the test would be conducted on board of a Gabya class frigate, it is possible that these tests are now conducted on board of TCG Sokullu Mehmet Paşa as the photographic evidence suggests.

DÜFAS is a towed low frequency active sonar project initial by the Research and Development department of SSB and being developed by Aselsan, Armelsan and Nanotech.

Mine Scare In The Black Sea

Mine damage on Musca class minesweeper Lieutenant Dimitrie Nicolescu. Photo: Dobrogea TV

On 8 September 2022, a Romanian ship reported a floating mine approximately 25 nautical miles northeast of Constanta harbour. The mine is believed to be one of the mines laid during the Russian invasion of Ukraine.

The Romanian Naval Forces deployed Musca class minesweeper Lieutenant Dimitrie Nicolescu to destroy the mine. However, when the minesweeper arrived at the site the weather and sea conditions worsened. With a wind speed of 10 – 12 m/s and wave height of 1.5 – 2 meters, the minesweeper was not able to deploy the RHIB with the EOD team on board. At night the mine swept through the storm and hit the ship on her astern port side.

According to Romanian Naval Forces, the detonation created a small hole, at the water line. The damage appears to be limited though there had been some ingress through the hole. the 75-strong crew on board has not suffered any injuries.

The minesweeper Lieutenant Dimitrie Nicolescu returned to her homeport Constanta with the help of the navy tugs Grozavul and Viteazu, that provided assistance and research against the mines.

Since the start of the Russian invasion of Ukraine 30 mines have been found and destroyed in the Black Sea. Here is the list of them

Date Mines Location Country Action
26.03.2022 1 Anchorage area Türkeli north of Bosphorus Turkey Turkish navy EOD teams dragged the mine to their Exercise area near the northern entrance of the Bosphorus and destroyed it.
28.03.2022 1 Off the shore of İğneada town Turkey Turkish navy EOD teams neutralised the mine in location.
28.03.2022 1 39 nautical miles off the Black Sea, across from Capu Midia Romania Romanian navy EOD teams neutralised the mine in location.
6.04.2022 1 Off the shore of Kefken town Turkey Turkish navy EOD teams neutralised the mine in location.
6.04.2022 1 Crimean shore Russia Mine washed ashore on an unspecified Crimean beach.
30.06.2022 1 27 nautical miles east of the mouth of the Kamchia river Bulgaria Bulgarian naval EOD team neutralised the mine in location.
31.07.2022 1 2 nautical miles off Eforie town Romania Romanian navy EOD teams neutralised the mine in location.
8.09.2022 1 25 nautical miles northeast of Constanta harbour Romania Romanian Navy mine sweeper Lieutenant Dimitrie Nicolescu was damaged when the mine could not be neutralised by EOD teams due to bad weather
1.07.2022 22 Ukrainian coast Ukraine 20 mines were destroyed by Ukrainian forces. Locations and dates are unknown.

As always any corrections or additions to the list above are welcomed.

New Sensors For Gabya Class Frigiates

A photo of TCG Gaziantep with the new electro-optic sensor. Photo: Oğuz Eroğuz. Used with permission.

The Turkish Navy started to upgrade the Gabya class frigates with a new electro-optic sensor.

The sensor was first observed on board TCG Gökçeada a couple months ago, the new electro-optic sensor appeared on board TCG Gaziantep this week. The ship was in overhaul. The E/O seems to be installed on a special pedestal on top of the bridge.

While there are no official announcements either from the Turkish Navy or Aselsan the system used on board seems to be the Denizgözü-Ahtapot version.

According to Aselsan Ahtapot is an E/O reconnaissance and surveillance system. The system has high-performance IR, HDTV and Spotter cameras, and an eye-safe laser range finder.

The sensor was specifically designed for naval use on board large ships. The first ship it was installed was on TCG Burgazada.

The lack of a dedicated E/O reconnaissance and surveillance system on board Gabya class frigates was an important shortcoming. With the installation of Ahtapot E/O, this shortcoming will be rectfied.

First Steel Cut For The New OPV


The first steel is cut for the Turkish Navy offshore patrol vessel Akhisar on 9 April 2022.

The OPV is being developed by Asfat and is based on the Milgem class corvettes. By using the hull of the Milgem class ships the OPV will be built in a shorter time and at a lower cost.

The OPV will have a very different main propulsion system from the Ada class corvettes. These ships will have a combined diesel-electric or diesel engine combination (CODELOD). This combination will give the ships a cruising range of 4500 miles and an economical speed of around 15 knots with very low fuel consumption. The crew will be 104.

According to Asfat these OPVs will be built with the fitted for but not with design philosophy, which will allow the integration of newly developed national weapon and sensor systems.

Dynamic Manta 2022 Has Started

The participating warships and submarines in one photo. Original photo by NATO Marcom, improvements by me.

NATO’s Submarine Warfare Exercise Dynamic Manta 2022 kicked on 21 February 2022, off the Sicilian coast, with ships, submarines, aircraft and personnel from 9 Allied nations.

According to the NATO press release, submarines from France, Greece, and Italy joined surface ships from Canada, France, Greece, Italy, Spain, Turkey, the U.K. and the U.S. for the exercise. Maritime patrol aircraft from Canada, France, Germany, Greece, Italy, the U.K. and the U.S. support the simulated, multi-threat environment during the exercise.

The aim of this exercise is to provide all participants with complex and challenging warfare training to enhance their interoperability and proficiency in anti-submarine and anti-surface warfare skills, with due regard for safety.

Aselsan Gökdeniz CIWS System Will Be Tested On Board TCG Sokullu Mehmet Paşa

Today the Rhein class auxiliary ship, TCG Sokullu Mehmet Paşa, left her homeport in Tuzla, İstanbul and headed to the Black Sea.

TCG Sokullu Mehmet Paşa and her sister TCG Cezarli Hasan Paşa have two 100mm gun turrets. The aft turet on board of TCG Sokullu Mehmet Paşa was removed in 2018. She was used as test ship for the Aselsan made close in weapon system Korkut-D in May 2018.

After the completion of these tests, the Korkut-D mount and the associated hardware was removed from the ship.

Today TCG Sokullu Mehmet Paşa was spotted with a new gun system installed. While the whole gun system and the associated radars and other sensors were under wraps the shape of the system is very distinguishable. The system to be tested is the Gökdeniz close-in weapon system.

Gökdeniz consists of one unmanned gun turret with two 35mm guns, an X band 3-D tracking radar and one fire control radar with electro/optical sensors. All subsystems of the Gökdeniz system are recognizable on board.

The gun turret has been remodelled from her initial version making it suitable to be retrofitted in place of the existing CIWS systems on board. The guns can use the ATOM 35mm airburst ammunition developed by ASELSAN. ATOM is a smart ammunition, having a base fuze increasing the effectiveness of the barreled guns. Thus such ammunition is an important option to fight against small and high-speed targets.

The X band tracking radar has a range of 100km. With its phased array, multi-beam antenna the radar can track multiple air targets simultaneously.

The Gökdeniz close-in weapon system will be installed onboard Barbaros class frigates during their mid-life upgrade, İ class frigates and in the future other ships.

Turkish Parliament Extends The Presence Of The Navy In Gulf Of Aden For One Year

On 2nd February 2022, The Grand National Assembly of Turkey, extended the presence of the Turkish Navy in the Gulf of Aden, Arabian Sea, and adjacent seas for one more year.

The first bill allowing the Turkish government to deploy Turkish Naval Forces for anti-piracy operations was accepted on 10 February 2009. It was extended in one year periods ever since.

Turkish warships are  tasked with:

  • Performing reconnaissance and patrol duties,
  • Calling on ships suspected of piracy/ armed robbery, on the radio, boarding them if their flag country approves and interfering by the international law if the ship is not showing any flag,
  • Escorting and protecting merchant ships,
  • Helping merchant ships under the attack of pirates/sea robbers,
  • Intervening, stopping, neutralizing, and confiscating any vessels used by pirates/sea robbers, and using proper force if necessary,
  • Arresting and detaining pirates/sea robbers and armed persons in these vessels,
  • Accepting the representatives of the countries that will prosecute pirates/ armed robbers on board, for the preparations of judicial proceedings, according to the UN resolution 1851.
  • Arresting and detaining, pirates/armed robbers on board until they are being handed over to the countries that will prosecute them,
  • Turning in, the suspects of pirates/sea robbers except for the case that these are Turkish citizens, to the authorities the nation where the pirates/sea robbers will be prosecuted,
  • Executing all kinds of policing duties including interrogation, collecting evidence.

Since 2009, the Turkish Navy took the helm of the multinational anti-piracy task force CTF-151, 6 times and made at least 21 deployments to the region in order to combat piracy.

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