Not long ago, it was reported that the first steel plate cutting ceremony of Türkiye's domestic aircraft carrier, domestic submarine and TF-2000 destroyer was held at the Istanbul Naval Shipyard and the Gerjuk Naval Shipyard. The steel plate cutting ceremony is an important node in the ship construction process, marking the official launch of the new ship construction project. It is worth noting that this is the first time that Türkiye has designed and built a conventional submarine on its own.

  Türkiye's domestic submarine model. Data picture

  Since the 1950s, Türkiye has relied on purchasing and introducing American and German submarines to build its own underwater power, and it is difficult to get rid of its technological dependence on Western countries. In 2012, Türkiye launched the domestic submarine project. This year, the project has officially entered the construction stage. Türkiye's Ministry of Defense said that this is the first time Türkiye has designed and built a conventional submarine on its own, and the degree of localization of technology is "very high". In the future, after domestic submarines are put into service, the combat strength of the Turkish Navy will be enhanced.

  Procure and introduce advanced foreign submarines to build underwater combat forces

  Türkiye spans the Eurasian continent, and the Turkish Strait is the only channel connecting the Black Sea and the Mediterranean. It has been a must-fight for military strategists throughout history, and its strategic position is very important.

  In 1923, after the founding of the Republic of Türkiye, it attached great importance to naval development and successively introduced multiple submarines from Germany, Italy, Britain and other countries to enrich its underwater combat forces. In 1952, after Türkiye joined NATO, the United States sold submarines to support Türkiye. However, by the 1970s, these submarines were seriously aging and faced retirement.

  In order to maintain its underwater combat power, Türkiye ordered six submarines from Germany. The first three ships were built by a German shipyard, while the latter three were provided by Germany to be assembled at the Gerjuk Naval Shipyard, Türkiye.

  The Gerjuk Naval Shipyard has a long history and was originally a floating dock to meet the construction and maintenance of Turkish naval warships during World War I. The factory was built on the basis of a floating dock in 1926. After decades of development, the Gerjuk Naval Shipyard has become the second largest shipyard in Türkiye after the Istanbul Naval Shipyard. Assembling the submarine allowed the factory to accumulate a certain amount of submarine construction experience, and since 1980, it has been fully responsible for the maintenance of German submarines, realizing the localization of submarine overhaul.

  In 2007, the Turkish Navy issued a bid for the procurement of six new AIP conventional power submarines. The bidding products include the 214TN submarine from the German Horvaz Shipyard, the crocodile-class submarine from the French Shipbuilding Bureau, and the S80 submarine from the Spanish Navantia Company. In 2009, the German Horvaz Shipyard successfully bid and signed a contract to export six 214TN submarines to Turkey.

  According to the contract, Türkiye is qualified to build a 214TN submarine in the local area. But soon after, the relationship between the two countries was tense and the project was progressing slowly. Until 2015, the first ship, "Pili Reis", started construction at the Gerjuk Naval Shipyard. The first ship of the 214TN submarine was launched in 2020 and is planned to complete the construction of six submarines and be put into use by 2029.

  It is reported that Turkish companies participated in 80% of the workload of the 214TN submarine - the detection, communication, combat management and the development and integration of this batch of submarines, as well as most of the hull construction work. German companies mainly provide basic submarine structure, turbine propulsion system and AIP fuel cells. By participating in the 214TN submarine project, Turkish companies have accumulated experience in submarine design and construction, cultivated relevant professional and technical talents, laying a solid foundation for building domestic submarines.

  The first time to build a conventional submarine is no less difficult than building a domestic aircraft carrier

  As an underwater weapon platform, submarines have many unique advantages and are an important force in the military competition and confrontation of major powers. Building domestic submarines can intuitively reflect a country's manufacturing level in the shipbuilding industry.

  In 2012, Türkiye launched the domestic submarine project, and through independent development of new submarines, mastering core technologies such as submarine design, power system, weapon integration, etc., gradually getting rid of foreign technology and achieving independent national defense.

  After the domestic submarine project was launched, many local Turkish shipbuilding companies participated in the bidding. In 2019, a Turkish military-industrial company announced the submarine concept model TS1700 for domestic submarine projects. The TS1700 submarine can be regarded as a reduced version of the 214TN submarine, with an underwater displacement of 1,740 tons and a submersible depth of up to 300 meters. It can carry 31 personnel to sea for 90 days and carry up to 16 torpedoes, mines or missiles. It can support special operations and intelligence collection and surveillance missions.

  The Turkish Navy was not impressed by the TS1700 plan. In 2022, Gerjuk Naval Shipyard announced the progress of the domestic submarine project. The head of the factory said that the new submarine was approved by the Turkish Navy and the concept design has been completed. The new submarine is scheduled to begin construction in 2025, and the first ship is expected to be tested by the end of 2031 and will be delivered to the Turkish Navy immediately.

  In October 2024, Türkiye announced the new plan model of the Gerjuk Naval Shipyard for the first time. The boat's underwater displacement is 2,700 tons, nearly 1,000 tons more than the TS1700 submarine; it is equipped with air propulsion devices (AIP systems), and its endurance, submarine depth and weapon capacity are all higher than the submarines previously equipped by the Turkish Navy.

  The domestic submarine project is the largest submarine built in Turkey in history. Its structure is complex, cutting-edge technology and difficult to build, which is a great challenge to the Turkish shipbuilding industry. Some media commented on Turkey that it is no less difficult than building a domestic aircraft carrier.

  Overcome multiple technical difficulties and seize the initiative in military competition

  The emergence of submarines once subverted the style of naval combat and became an important weight on the strategic balance. However, behind the high value is the high investment in funds and the high threshold for technology.

  In the modernization of the Turkish naval, the construction of domestic submarines has attracted great attention. In synchronized with aircraft carriers and destroyers, the first new submarine ship was held at the Gerjuk Naval Shipyard. Türkiye's Ministry of Defense said that this is the first time Türkiye has designed and built a conventional submarine on its own, and the degree of localization of technology is "very high". In order to successfully build domestic submarines, they have overcome many technical difficulties.

  First, it does not rely on air propulsion technology. Modern conventional submarines generally use air-independent propulsion devices, with doubled underwater endurance, significantly reduced noise indicators, and significantly improved the combat effectiveness of submarines. In this regard, Türkiye once considered adopting Germany's fuel cell technology, but later moved to the development route of lithium batteries due to multiple factors. Lithium batteries have advantages such as high energy density, fast charging, and low maintenance costs, and are more suitable for small and medium-sized submarines. In 2023, Turkey's STM Company signed a cooperation agreement with a South Korean company, which is a global leading power battery company, providing Turkey with high-energy density lithium battery cells. Local companies will independently complete battery pack packaging, thermal management and system integration for AIP system research and development. In 2024, STM company showed off its domestic lithium battery AIP module in public testing, claiming that its submarine will last longer underwater.

  The second is low-noise pump jet propulsion technology. Pump jet propulsion technology is a technological leap in the development of submarine thrusters. It is better than traditional propellers in improving propulsion efficiency and reducing noise signals. It is the key to improving the submarine's underwater stealth capabilities and is also a complex system project. Türkiye's Defense Industry Bureau coordinates the technical planning and financial support of pump jet thrusters. The Turkish Science and Technology Research Council provides basic fluid mechanics and acoustic theoretical research, leads the development of thruster noise reduction algorithms, and optimizes the design through supercomputer simulation. Türkiye's Aselsan Company is responsible for the development of the core electromechanical control system of the propeller, while STM Company is responsible for the manufacturing and assembly of thruster components such as titanium alloy blades. In addition, companies in Germany, Sweden, Japan and other countries provide corresponding technical support.

  The third is advanced underwater weapons. The Turkish Navy requires new submarines to be able to perform various mission capabilities such as anti-submarine, anti-ship, land strike, and special operations. One of the main weapons of the submarine is the "Akaya" heavy torpedo developed by Locketsan Company. The company was founded in 1988 and is one of the core enterprises of Turkey's defense industry, focusing on the development of missiles, underwater weapons, etc. The "Akya" heavy torpedo it creates will completely replace the American and German heavy torpedoes used by the Turkish submarine forces. The submarine will also be equipped with domestically produced "Sparrow Eagle" anti-ship missiles. The missile is led by Türkiye's Locketsan Company, and Aselsan Company participates in the research and development. Locketsan Company provides stealth missile technology, and Aselsan Company is responsible for the development of seekers and control systems. In 2019, the missile completed its first maritime test launch, replacing the Turkish Navy's US-made "harpoon" anti-ship missile. In order to meet the requirements of strikes on land-based deep targets, Locketsan also developed a new missile vertical launch system for submarines for underwater launch cruise missiles, and overcome a series of technical difficulties such as sealing and impact resistance in high-voltage launch environments, missile water out-of-water attitude control.

  In addition, Aselsan Company has successfully completed the development of domestic sonar, combat management systems and other products. STM provides submarines with small special submarines and unmanned submarines.

  However, there are still many technical bottlenecks in Turkey's domestic submarine project, such as the efficiency and reliability of domestic AIP systems still need to be verified, the domestic production rate of lithium batteries does not reach more than 80%, and key components such as periscope optical systems still need to be imported.

  In general, the domestic submarine project shows the transformation of Türkiye's defense industry from technology introduction to independent innovation. It is understood that in order to achieve the independence of the submarine industry, Türkiye needs to establish 8 national laboratories and 3 special shipbuilding docks between 2025 and 2035. Through this project, Türkiye is expected to increase the localization rate of the national defense industry to more than 80%, and establish a full life cycle capability covering "design-construction-maintenance", driving the development of more than 300 military-industrial enterprises in China.

  Türkiye is one of the few countries in the Middle East that have a good industrial base. In recent years, Türkiye has accelerated its naval construction and its maritime strength has been continuously improved. Building new submarines is a major measure for Türkiye to seize the initiative in military competition. After the new submarine is successfully put into service, the Turkish Navy will be able to carry out military operations on a larger scale, and its influence on the security situation in the surrounding areas will be further enhanced, enhancing Türkiye's international status. (Wang Xiaomeng)

[Editor in charge: Wang Jinzhi]