TCG Hızırreis (S-331)

TCG Hızırreis is a new-generation Reis-class submarine built at the Gölcük Naval Shipyard Command for the Turkish Naval Forces. As the second vessel of the New Type Submarine Project, Hızırreis is among the most advanced platforms added to Türkiye’s submarine fleet, equipped with an air-independent propulsion (AIP) system, a modern combat management infrastructure, and indigenous software-integrated subsystems. Critical sections of the submarine, particularly the torpedo launch system and command and control block known as Section 50, were entirely developed and integrated domestically through a collaboration between STM and Gürdesan. This approach has ensured a high level of local contribution to Hızırreis’s internal systems and mission management.

Construction and Integration Process

The construction of TCG Hızırreis began in the late 2010s under the New Type Submarine Project. At the Gölcük Naval Shipyard, a modular construction method was employed, whereby hull blocks were manufactured separately and then assembled. This technique enabled more planned production scheduling and enhanced flexibility for maintenance and modernization activities.

Launched in 2022, Hızırreis entered the integration phase following its launch. During this phase, the integration of internal and external systems, installation of electronic components, and testing of energy and propulsion systems were carried out. The integration phase is the most critical stage between launch and commissioning. The integration of original software and hardware developed by Türkiye’s national defense industry companies played a vital role during this period. Furthermore, the domestic production and integration of Section 50 significantly enhanced the reliability and operational effectiveness of Hızırreis’s critical mission systems.

First Voyage and Dive

According to an announcement by the Ministry of National Defense on 18 September 2024, TCG Hızırreis successfully completed its first voyage and dive between 17 and 18 September 2024. This activity was regarded as one of the most important steps in the submarine’s sea acceptance trials.

During the first voyage, surface navigation, propulsion system performance, rudders and depth control surfaces, and navigation safety systems were tested. During the first dive, the submarine’s pressure resistance, maneuverability, ventilation, and safety systems were evaluated. The successful completion of these tests has paved the way for TCG Hızırreis to join the Turkish Naval Forces inventory according to the planned schedule.

The successful execution of Hızırreis’s first voyage and dive has also been viewed as a demonstration of Türkiye’s defense industry engineering capabilities. This is because not only the physical construction of the vessel but also its electronic infrastructure, command and control software, and mission systems were developed using domestic resources. In this context, Hızırreis’s mission systems and multi-weapon capability directly enhance the strength of the Turkish Navy.

Technical Equipment and Systems

TCG Hızırreis stands out due to its technical specifications. Its forward section, known as Section 50, was domestically produced to house torpedo launchers and critical command and control systems. As a result, Hızırreis is equipped with eight 533 mm torpedo tubes and offers multi-weapon capability, enabling the use of torpedoes, missiles, and naval mines. The crew capacity is estimated at approximately 27 to 30 personnel.

Its most notable feature is the air-independent propulsion (AIP) system. This system allows Hızırreis to remain submerged for weeks, unlike conventional diesel-electric submarines. Its silent cruising capability makes detection by enemy forces significantly more difficult and enables prolonged covert missions. The AIP system also enhances the platform’s strategic and long-range operational capabilities.

Submarine Information Distribution System (SIDS)

One of Hızırreis’s most important indigenous technological components is the Submarine Information Distribution System (SIDS), developed by HAVELSAN. SIDS collects data from sensors and control units onboard the submarine and distributes it via a centralized network. Additionally, its primary functions include recording mission data and ensuring mission continuity through a redundant architecture.

HAVELSAN began developing SIDS in 2011 and started delivering the system from 2020 onwards. As a result, Hızırreis’s information infrastructure is fully supported by indigenous software and hardware. This system operates in integration with the submarine’s combat management system, assuming a central role during combat operations.

Combat Management and Warfare Systems

The combat management system of Hızırreis has also been integrated by HAVELSAN. The submarine’s sonar, torpedo systems, electronic warfare, and communication equipment are coordinated through this system, enabling it to generate effective responses to various threat scenarios.

The weapon systems include 533 mm torpedo tubes capable of launching heavyweight torpedoes, anti-ship guided missiles, and naval mines. This capability transforms Hızırreis into not only a defensive platform but also a credible offensive weapon system.

Strategic Importance

TCG Hızırreis is one of the most critical platforms for enhancing the operational capacity of the Turkish Naval Forces. With its AIP technology enabling prolonged underwater operations, Hızırreis will significantly increase Türkiye’s effectiveness in its maritime zones in the Mediterranean, Aegean, and Black Seas, as well as in open ocean areas.

The submarine’s indigenous systems reduce Türkiye’s external dependencies and support the maturation of its national defense industry. In this regard, TCG Hızırreis is not merely a submarine but a tangible example of strategic technological advancement.