Germany Upgrades Brandenburg-class F123 Frigate FGS Bayern to Keep It Operational Until 2035.

Germany is modernizing the anti-submarine warfare frigate FGS Bayern (F217) under a multi-year overhaul that will extend the Brandenburg-class warship's service life until at least 2035. The investment strengthens the German Navy's surface fleet by renewing critical combat systems, sensors and propulsion while preserving a key NATO maritime capability.

The German Ministry of Defense has awarded Rheinmetall a contract worth several hundred million euros to carry out the comprehensive modernization of FGS Bayern (F217) at the company's Neue Jadewerft shipyard in Wilhelmshaven. Work is scheduled to begin following the contract award at the end of the second quarter of 2026 and continue through 2029, ensuring one of Germany's principal anti-submarine warfare frigates remains operational for another decade.

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Designed primarily for anti-submarine warfare at the end of the Cold War, F123 frigates continue to represent an important component of the German Navy's blue-water capabilities. (Picture source: US DoD)

The Brandenburg class comprises FGS Brandenburg (F215), commissioned in 1994, FGS Schleswig-Holstein (F216) in 1995, FGS Bayern (F217) in 1996 and FGS Mecklenburg-Vorpommern (F218), also commissioned in 1996. Designed primarily for anti-submarine warfare at the end of the Cold War, these frigates continue to represent an important component of the German Navy's blue-water capabilities. Extending Bayern's service life therefore helps preserve fleet strength while future naval programs are introduced.

According to information released by Rheinmetall on July 30, 2026, the contract includes the replacement of the Combat Management System, the complete overhaul of the ship's principal engineering systems, modernization of the radar suite, refurbishment of the propulsion system, and upgrades to its anti-submarine warfare capabilities. The objective is not only to restore the vessel's material condition after nearly three decades of service but also to adapt its performance to current operational requirements. The ship is already at Neue Jadewerft, where the removal of major onboard equipment is underway before it enters dry dock.

Displacing approximately 4,900 tonnes at full load, the F123 frigates measure 138.85 meters in length with a beam of 16.7 meters and carry a complement of approximately 236 personnel. From the outset, the design incorporated radar signature reduction measures that reportedly reduced the ships' radar cross section to roughly one tenth that of the Bremen-class frigates they replaced. These characteristics, combined with substantial endurance and a balanced weapons suite, have enabled the class to remain operational despite its age.

Propulsion is based on a Combined Diesel or Gas (CODOG) configuration integrating two General Electric LM2500 gas turbines producing a combined output of approximately 38 MW with two MTU 20V 956 TB92 diesel engines driving two controllable pitch propellers. This arrangement allows speeds in excess of 29 knots while providing a range of approximately 4,000 nautical miles at 18 knots, supporting extended deployments in the North Atlantic, Baltic Sea and Mediterranean.

The combat system modernization represents one of the central elements of the program. The Combat Management System integrates information from onboard sensors, tactical data links and weapon systems into a single operational picture, reducing engagement times and improving battlefield awareness. The F123 class had previously undergone the Fähigkeitsanpassung FüWES modernization program, which introduced the SABRINA 21 combat management system derived from Thales TACTICOS, together with an upgrade to the MSSR 2000 I identification friend or foe system. The latest modernization is expected to further improve data fusion, information processing and interoperability with NATO naval forces.

Although Rheinmetall has not disclosed the exact configuration of the new sensor suite, the original system includes the Thales LW08 long-range air surveillance radar, the SMART-S three-dimensional surveillance radar and two STIR 180 fire control radars. Modernization programs launched in recent years also envisaged integrating Saab's Sea Giraffe 4A, Sea Giraffe 1X, CEROS 200 fire control radar and 9LV combat management system, illustrating the scale of the technological renewal planned for the class. Below the waterline, Bayern remains the only ship of the class equipped with the experimental Atlas TASS 6-3 low-frequency towed array sonar in addition to the standard DSQS-23BZ bow sonar, providing enhanced long-range submarine detection capability.

Despite its age, the F123 retains a balanced weapons configuration. Its air defense is centered on a 16-cell Mk 41 Vertical Launching System, capable of carrying either RIM-7 Sea Sparrow missiles or up to 64 Evolved Sea Sparrow Missiles (ESSM) through quad-packing, providing an engagement range of more than 50 kilometers. Anti-ship capability is provided by eight RGM-84 Harpoon missiles, while close-range defense relies on two Mk 49 Rolling Airframe Missile (RAM) launchers and two remotely operated MLG27 gun systems. Anti-submarine warfare is supported by two twin 324 mm Mk 32 torpedo launchers firing Mk 46 torpedoes, complemented by facilities for two Sea Lynx Mk.88A helicopters, extending the ship's submarine detection and engagement envelope.

This modernization will keep one of the German Navy's principal anti-submarine warfare platforms in service at a time when undersea warfare has again become a priority in the North Atlantic and Baltic Sea. The integration of an updated combat management system, together with renewed sensors and refurbished propulsion systems, will improve the ship's ability to detect, track and engage multiple threats while operating within multinational naval task groups. Enhanced command and control functions will also improve interoperability with other NATO navies during escort missions, maritime surveillance, anti-submarine warfare and integrated air defense operations in the Baltic Sea, the North Sea and the North Atlantic.

Beyond Bayern itself, the modernization forms part of Germany's broader naval capability renewal effort. Berlin is simultaneously advancing the introduction of the F126 frigates, the modernization of other F123 and F124 class ships, the acquisition of P-8A Poseidon maritime patrol aircraft, and the development of the future Type 212CD submarines in cooperation with Norway. By extending the operational service life of the Brandenburg class until at least 2035, Germany maintains continuity in its surface combat capabilities during this transition period and avoids a capability gap before its next generation of naval platforms enters full service.

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.

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