STM TCG Karadeniz (F-520)

History

TCG Karadeniz (F-520) is an Istanbul-class multirole guided-missile frigate built for the Turkish Naval Forces. It is the sixth ship of the class and forms part of Türkiye's MILGEM national warship program.

Sedef Shipyard launched TCG Karadeniz on 27 July 2026. The ship subsequently entered the fitting-out and integration phase and had not yet been commissioned.

The frigate combines anti-surface, anti-aircraft and anti-submarine capabilities. Its reported equipment includes the ADVENT combat management system, a 16-cell MiDLAS vertical launching system and 16 Atmaca anti-ship missiles.

Development of the Istanbul class

The Istanbul class originated as the second major surface-combatant phase of MILGEM. The design was developed from the smaller Ada-class corvette with a longer hull, greater displacement, increased endurance and additional space for weapons and combat systems. The class is also known as the Istif class, I class and TF-100.

Development of the lead ship, TCG Istanbul (F-515), began during the 2010s. Its ceremonial steel cutting took place in January 2017, it was launched on 23 January 2021 and it entered service on 19 January 2024. Information about the early program and its original requirements was reported by Defense News.

Serial construction

A December 2023 agreement expanded serial construction through cooperation between STM and the TAIS shipyard consortium. Anadolu, Sedef and Sefine shipyards received ships for parallel construction. This arrangement allows several hulls to progress through assembly, fitting out and trials at the same time.

Sedef Shipyard built TCG Karadeniz as the sixth Turkish ship of the class. Its launch on 27 July 2026 followed the launch of TCG Akdeniz earlier that year. A contemporary account of the ceremony and program status was published by Army Recognition.

Launching did not represent entry into naval service. TCG Karadeniz still required the installation, connection and testing of propulsion, electrical, sensor, communication and weapon systems before acceptance by the Turkish Naval Forces.

Design

The Istanbul-class hull is 113.2 m long, approximately 14 m longer than the Ada-class design. The increased hull volume supports a larger missile armament, expanded combat-information spaces, additional accommodation and machinery compartments, and greater fuel and electrical capacity.

Propulsion

TCG Karadeniz uses a combined diesel and gas propulsion arrangement. Two MTU diesel engines and one General Electric LM2500 gas turbine drive two controllable-pitch propellers. The diesel engines support economical patrol and transit, while the gas turbine supplies additional power for high-speed operation.

Combat systems and sensors

The ship's combat systems are integrated through Havelsan's ADVENT combat management system. ADVENT combines information from navigation, surveillance, sonar, electronic-warfare, communication and weapon-control systems into a common tactical picture.

The reported sensor fit includes the Aselsan CENK-series active electronically scanned array surveillance radar, the ALPER low-probability-of-intercept surface-search radar and the AKREP fire-control radar. A FERSAH hull-mounted sonar provides an organic underwater-detection capability. The ARES-2N electronic-support suite detects and classifies radar emissions, while HIZIR provides torpedo warning and countermeasure functions.

Armament

The frigate carries 16 Atmaca anti-ship missiles in four quadruple launchers. Its 16-cell MiDLAS vertical launching system is intended to support different surface-to-air missile configurations. The reported options include one SİPER Block 1 missile per cell or as many as four HİSAR-D RF missiles per cell. A mixed operational load would depend on mission requirements.

Gun armament consists of an MKE 76 mm main gun, a twin-barrel Aselsan GÖKDENİZ 35 mm close-in weapon system and two Aselsan SMASH 25 mm remote weapon stations. Two twin 324 mm torpedo launchers provide an onboard anti-submarine weapon capability and can employ Orka or Mk 46-series lightweight torpedoes.

Aviation and boats

The stern contains a flight deck and hangar for an S-70B Seahawk helicopter and compatible rotary-wing unmanned aircraft. The helicopter can extend the ship's surveillance and anti-submarine reach beyond the coverage of its hull-mounted sensors. The frigate also carries two rigid-hulled inflatable boats.

Program status

As of its July 2026 launch, TCG Karadeniz was undergoing fitting out at Sedef Shipyard. No commissioning date or confirmed operational deployment was provided by the available sources.

The Turkish program covers eight Istanbul-class frigates. TCG Istanbul was already in service when TCG Karadeniz was launched, while the remaining ships were at different stages of trials, fitting out or construction. The class is intended to occupy the multirole layer between the smaller Ada-class corvettes and the planned TF-2000 air-defense destroyers.

Operators

• Türkiye: TCG Karadeniz is being built for the Turkish Naval Forces and remained in the fitting-out phase following its July 2026 launch.

Specifications (TCG Karadeniz)

General characteristics

• Type: Multirole guided-missile frigate
• Class: Istanbul class
• Pennant number: F-520
• Designer and prime contractor: STM
• Builder: Sedef Shipyard
• Displacement: Approximately 3,100 to 3,200 tonnes at full load
• Length: 113.2 m
• Beam: 14.4 m
• Draft: 4.05 m
• Complement: 123
• Boats: Two rigid-hulled inflatable boats

Propulsion

• Arrangement: Combined diesel and gas
• Gas turbine: One General Electric LM2500
• Diesel engines: Two MTU diesel engines
• Propellers: Two controllable-pitch propellers

Performance

• Maximum speed: More than 29 knots
• Economical speed: 14 knots
• Range: Approximately 5,700 nautical miles (10,600 km) at 14 knots
• Endurance: At least 15 days without replenishment

Armament

• Main gun: One MKE 76 mm gun
• Close-in defense: One twin-barrel Aselsan GÖKDENİZ 35 mm system
• Remote weapon stations: Two Aselsan SMASH 25 mm systems
• Anti-ship missiles: 16 Atmaca missiles in four quadruple launchers
• Vertical launching system: 16-cell MiDLAS for compatible surface-to-air missiles
• Torpedoes: Two twin 324 mm launchers for lightweight torpedoes

Aviation facilities

• Facilities: Flight deck and hangar
• Supported aircraft: S-70B Seahawk helicopter and rotary-wing unmanned aircraft

Related equipment

• Ada class: Turkish corvette design from which the Istanbul class was developed.
• TF-2000: Planned Turkish air-defense destroyer intended to provide greater air-defense capacity than the Istanbul class.