The F124 Sachsen class, also known as the F124 class, was among the most important air defense frigates of the German Navy.
After the Cold War, the Germans had their own challenges in strategy and force structure to create frigate classes different from those previously built. The First Gulf War was a prime example of post-Cold War operations, showing that larger, longer ranged, and more capable surface combatants would be required to operate alongside their American counterparts to support activities along the Eurasian littoral against hostile states. A smaller number of these more capable ships also met the requirements of European parliaments, thereby reducing the level of the defense force and budget.
Along with other European warships such as the Dutch De Zeven Provincien, the Franco-Italian multipurpose frigate FREMM ships, the German Sachsen-class represents the development of today’s frigate design. Compared to past frigate ships, these ships are a quantum improvement over their Cold War predecessors. The Sachsen-class occupies a special place in the structure of the German navy, which is closer to the United States Arleigh Burke-class destroyer than the previous frigate designs.
The Sachsen class, also known as the F124 class, was among the most important air defense frigates of the German Navy. The class is based on the F123 Brandenburg predecessor, but emphasizes advanced stealth capabilities, designed to deceive the opponent’s radar and acoustic sensors. Although it carries the “F” symbol, which is in the frigate segment, but Sachsen is actually a destroyer with a full displacement of 5,800 tons. The ship is 143m (469 ft) long, the beam is 17.44m (57.2 ft) and the draft is 6m (20 ft).
The Sachsen air defense frigate class consisted of three ships, ordered by the German government in 1996 at a cost of € 2.1 billion, or € 700 million each. The three frigates include the lead ship F219 Sachsen, followed by F220 Hamburg, and the third, F221 Hessen. The Sachsen F219 was commissioned in 2003, the other two were in 2004 and 2006, respectively. The Sachsen class is considered one of the most advanced warships, fitted with a variety of advanced American and European weapons and equipment, and it is also one of the most expensive German shipbuilding programs.
Sachsen’s hull design is inherited from the previous Brandenburg class. The advanced stealth technology has been applied to reduce radar signatures significantly, helping to hide themself from the enemy radar. The ships were built using the MEKO modular construction and incorporate seven watertight compartments, allowing for easy maintenance and flexibility to add new weapons and sensors in the future. To operate, the frigates need a crew of 230 sailors and can accommodate additional 13 aircrews as part of a squadron commander’s staff. They can operate continuously for 21 days at sea without supply ships.
The F124 class is equipped with a combined diesel and gas propulsion system, driving two shafts, controllable-pitch propellers. These include two MTU V20 diesel engines producing 7.4 MW each, combined with one General Electric LM2500 gas turbine. The ships can reach a maximum speed of 29 knots (54 km/h), a range of up to 4,000 knots (7,400 km) at a fuel economy speed of 18 knots.
Like other new-generation frigates, the Sachsen class also has a flight deck and a hangar to accommodate two Sea Lynx Mk.88A or 2 NH90 helicopters. To increase anti-ship warfare, helicopters can be equipped with torpedoes, air-to-surface missiles Sea Skua, and heavy machine gun.
The Sachsen’s combat system revolves around APAR and SMART-L multi-function radars. APAR is the first Active Phased Array Radar for warships developed by Thales Nederland. Its structure consists of 4 radar arrays fixed on 4 sides, similar to the AN/SPY-1 of the Aegis system, providing 360-degree coverage and no latency. Each radar array has 324 transceivers operating on the X band, simultaneously tracking 200 aerial targets from 150 km and 75 km with surface targets, guiding 32 semi-active radar homing missiles in flight simultaneously, including 16 in the terminal guidance phase.
Meanwhile SMART-L is a long-range air and surface surveillance radar based on the D band, working in passive mode with 16 transmitters and 8 receivers. It was also developed by Thales Nederland to support APAR. The SMART-L radar has a maximum range of 400 km with aerial targets and 65 km for stealth missiles. An upgraded software later expanded to 480 km and identified intercontinental ballistic missiles from 1,000 km, simultaneously tracking 1,000 air targets or 100 surface targets.
These ships were optimized for the anti-air warfare role. The primary anti-air weapons are the 32-cell Mk 41 Mod 10 vertical launching system, equipped with twenty-four SM-2 Block IIIA missiles and thirty-two Evolved Sea Sparrow missiles. Point-defense against cruise missiles is provided by a pair of 21-round Rolling Airframe Missile launchers. The ships are also equipped with two four-cell RGM-84 Harpoon anti-ship missile launchers. In 2013, the German Navy considered modifying the ships’ long-range search radar to allow the SM-2 missiles to be used in an anti-ballistic missile capacity.
For defense against submarines, the frigates carry two triple-launchers for the 324mm (12.8 in) MU90 Impact torpedoes. The ships also carry a variety of guns, including one dual-purpose 62-caliber 76mm (3 in) gun manufactured by OTO Melara. They are also armed with two Rheinmetall 27mm (1.1 in) MLG 27 remote-controlled autocannons in single mounts.
The ship’s electronic countermeasures suite includes an EADS Systems and Defence Electronics FL1800 SII ECM system and six Sippican Hycor SuperRBOC launchers which fire chaff and flares. The ship is equipped with a Thales Nederland Sirius IRST long-range infra-red surveillance and tracking sensor. STN Atlas MSP 500 electro-optical fire control system provides target acquisition and tracking for the main gun. The bow sonar is the STN Atlas Elektronik DSQS-24B.
The Sachsen-class air defense destroyer has two variants: De Zeven Provinciën and Iver Huitfeldt, serving in the Dutch and Danish Navy. The displacement of these variants increased to 6,000 tons and 6,600 tons, armed with 32 SM-2 Block IIIA missiles and 32 RIM-162 Evolved SeaSparrow Missiles.
Compared to the Aegis destroyers and cruisers currently serving in the US Navy, the Arleigh Burke and Ticonderoga, the Sachsen frigates are more highly regarded in the surveillance radar, their weapons are also much more diverse.