Türkiye Eyes Asian Submarine Deals as First MİLDEN Atılay Unit Enters Construction.

Türkiye has launched construction of its first fully indigenous air-independent propulsion attack submarine, marking a significant step toward sovereign underwater warfare capability. This development strengthens its ability to operate stealthily for extended periods, enhancing deterrence and survivability in contested maritime environments.

The Atılay-class under the MİLDEN program is designed to deliver long-endurance submerged operations without surfacing, enabling covert intelligence gathering and precision strike missions. This capability aligns with broader trends in naval modernization, where autonomy, low observability, and sustained underwater presence are critical to sea control and power projection.

Related Topic: Türkiye starts construction of first MILDEN national submarine for underwater deterrence

Mock-up of Türkiye’s MİLDEN Atılay-class submarine displayed at DSA 2026 in Malaysia (Picture source: Army Recognition)

The program builds on experience gained through the licensed production of the Reis-class submarines derived from the German Type 214TN, where the gradual integration of local systems formed the foundation for MİLDEN. The Turkish Ministry of National Defense and the Presidency of Defense Industries oversee the program, while Gölcük Naval Shipyard is responsible for design and construction, supported by STM for engineering. Several domestic defense companies are directly involved, including Aselsan for sensors and electronics, Roketsan for weapon systems, and Havelsan for combat management systems.

The transition to an industrial phase was confirmed in early December 2025 when the Ministry of National Defense announced, during a press briefing in Ankara, the start of steel cutting and assembly of the first submarine blocks at Gölcük Naval Shipyard. This step took place alongside the beginning of construction of the first TF 2000 air-defense destroyer blocks at Istanbul Naval Shipyard, as well as the signing of contracts valued at 6.5 billion dollars under the Steel Dome air and missile defense program. Taken together, these developments reflect an effort to anchor future fleet growth in domestic shipyards, sensors, and weapon systems.

Initial design work was completed in 2022 before the program moved into detailed design. Construction of a first test block began in 2024, followed in December 2025 by the official keel-laying and naming ceremony for the lead submarine. The name Atılay refers to an earlier Turkish submarine built in the 1930s, highlighting continuity in national naval development.

The submarine is designed with larger dimensions than the previous generation. With a surfaced displacement of approximately 2,700 tons and a length exceeding 80 meters, it aligns with modern medium-sized attack submarines. The crew is estimated at 40 to 50 personnel, reflecting partial automation and the integration of advanced onboard systems. It is described as a diesel-electric submarine incorporating an air-independent propulsion system intended to extend submerged operations without the need for snorkeling.

The propulsion architecture combines diesel-electric systems with air-independent propulsion. This configuration allows the submarine to remain submerged for extended periods, reducing acoustic signature and exposure to detection. The AIP solution is based on proton-exchange membrane fuel cells, supported by a methanol reforming system and lithium-ion batteries. This setup is intended to provide several days of submerged endurance while maintaining low acoustic output, a requirement in enclosed and heavily monitored maritime environments such as the Eastern Mediterranean and the Black Sea.

The onboard systems reflect an emphasis on technological autonomy. The combat management system, derived from national architectures such as GENESIS or ADVENT, enables data fusion and weapons control in complex underwater environments. The sonar suite developed by Aselsan includes a bow-mounted sonar, flank arrays, and a towed array sonar for long-range passive detection, allowing coverage against low-signature targets. A non-penetrating optronic mast replaces the traditional periscope, improving discretion while providing day and night observation capabilities.

Armament is based on eight 533 mm torpedo tubes capable of deploying the Akya heavyweight torpedo developed by Roketsan. This torpedo has a range of several tens of kilometers and uses both active and passive guidance, enabling engagement of surface vessels and submarines. The submarine is also designed to launch a submarine-launched version of the Atmaca anti-ship missile, already deployed on surface vessels. Atmaca has a range exceeding 220 kilometers, follows a sea-skimming profile, and combines inertial navigation, satellite guidance, and terminal active radar homing.

Over time, integration of the Gezgin cruise missile is planned to provide a land-attack capability against targets at long range. This addition would extend the submarine’s engagement spectrum to include anti-submarine warfare, naval interdiction, and selective deep-strike missions. Concept models displayed at defense exhibitions also suggest the possible integration of a MiDLAS vertical launch system, although this configuration remains to be confirmed for initial units.

Written By Erwan Halna du Fretay - Defense Analyst, Army Recognition Group
Erwan Halna du Fretay holds a Master’s degree in International Relations and has experience studying conflicts and global arms transfers. His research interests lie in security and strategic studies, particularly the dynamics of the defense industry, the evolution of military technologies, and the strategic transformation of armed forces.