Saxony class (2001)

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Saxony class
The Hessians at Portsmouth Naval Base
The Hessians at Portsmouth Naval Base
Ship data
country GermanyGermany (naval war flag) Germany
Ship type frigate
Shipyard * Blohm + Voss
Construction period 1999 to 2005
Launch of the type ship January 20, 2001
Units built 3
period of service Since 2004
Ship dimensions and crew
143 m ( Lüa )
width 17.44 m
Draft Max. 6.0 m
displacement 5800  t
crew 255 soldiers
Machine system
machine RENK CODAG-Cross Connect
1 GE LM 2500 gas turbine
2 MTU 1163 diesel
performanceTemplate: Infobox ship / maintenance / service format
38,300 kW (52,074 hp)
29 kn (54 km / h)

The class 124 ( also called the Sachsen class after the type ship ) is a warship class of the German Navy consisting of three frigates , which was primarily designed for association flight reconnaissance. The Sachsen entered service on November 4, 2004. It was followed by Hamburg (commissioning December 13, 2004) and Hessen (commissioning April 21, 2006).

Since the Sachsen class can meet the operational contracts under the naval war alone without further support, is in the ships despite the official classification as a frigate de facto to destroyers , although current destroyers as the Arleigh Burke-class destroyer of the US Navy or the Daring class of the British Royal Navy via a u. a. Much larger number of long-range anti-aircraft missiles such as the Raytheon Standard Missiles (SM) 2 to SM 6 , or the European MBDA Aster 30 . Accordingly, some specialist books classify the Saxony class. The three ships of the class replaced the destroyers of the Lütjens class , which were decommissioned between 1998 and 2003, in a ratio of 1: 1.


The name Sachsen was first borne by the tank corvette Sachsen of the class of the same name , the names Hamburg and Hesse last by destroyers of the 101 / 101A class .


In the early 1980s, Germany took part in the NATO Frigate Replacement for 90s (NFR-90) project, the aim of which was to develop a uniform frigate design for all eight participating NATO countries. Because of the great differences between the needs of the individual navies, the project had to be stopped in 1989. The USA built the Arleigh Burke class on a national basis , while Great Britain, Italy and France decided on a new joint project, the Horizon Common New Generation Frigate (Horizon CNGF) . The remaining four countries, Spain, Germany, the Netherlands and Canada, had feasibility studies carried out on a national basis. Finally, Spain, Germany and the Netherlands were able to agree on a basic design to be developed on a trilateral basis, which would be built and designed nationally. As part of this Trilateral Frigate Cooperation , or TFC for short, the F124 class was built in Germany, the Álvaro de Bazán class in Spain and the De Zeven Provinciën class in the Netherlands .

Similar to the Bremen class being the sister class of the Kortenaer class , the Saxony class is therefore the sister class of the De Zeven Provinciën class. Although both ships are externally similar, they have a number of differences: The De-Zeven-Provinciën -class has 40 cells for the VLS ( Sachsen -class 32 cells) for 32 SM-2 and 32 ESSM, only one on-board helicopter ( Sachsen -Class two), two gas turbines ( Sachsen -class one), a 127/54 Compact as a gun ( Sachsen -class 76/62 Compact) and the AN / SLQ-25 Nixie for torpedo defense.

The first unit in Saxony (F 219) was completed in January 2001. During the first test drive in August 2001, it was able to prove its efficiency. The tests were successful - apart from the usual minor problems. The highlights of the program were the acoustic measurement of the Saxons off Eckernförde at the beginning of September 2001 and dynamic testing of the radar systems with, among other things, tornadoes and helicopters from the German Navy. The frigate then moved the technical tests to the Skagerrak for a further week to continue before returning to Blohm + Voss on September 13th. In particular, the new developments CDS software as well as SMART-L and APAR were subjected to initial tests. Since there is no comprehensive onshore test facility within the scope of the corresponding development project, but only various subsystems, there was for the first time the opportunity to test the facilities in their final series configuration in interaction and under sea conditions and to record corresponding data for the further development of the systems. On the frigate Sachsen in the Skagerrak on September 18, 2002, the proof of capability for the new generation of sonar systems was provided and it was shown that the sonar can deliver good results even at high speed levels.

According to information from the Schleswig-Holstein newspaper on Sunday in 2006, the frigates were allegedly unable to defend themselves adequately against attacks by aircraft or missiles due to software errors in the command and control system. However, the frigates could be used in the context of the UN Lebanon mission . In his closing speech at the 48th Historical-Tactical Conference of the Fleet in January 2008 in Warnemünde, the fleet commander said that full operational capability could only be expected in the first half of 2010.

In September 2011 the Sachsen completed a missile test in the Overberg Test Range off the coast of South Africa , in which an Exocet anti -ship missile fired on the Saxons by the frigate Schleswig-Holstein was successfully intercepted. Several drones were also destroyed in this maneuver . This enabled the operational capability of the air defense systems to be demonstrated.

In December 2012 the Defense Committee of the Bundestag approved 75.1 million euros for the modernization of the three ships of the class, which will be carried out by the companies Atlas Elektronik and Thales Group until 2017 . Specifically, it is about replacing the obsolete console computer, the data recording module and various network components with the latest generation of components. The ability to supply critical CDS shares is thereby also established. A deliberate side effect is that, after the hardware has been regenerated, the computer systems will in future offer sufficient capacity for the integration of new subsystems and future CDS functionalities.


A possible conflict with the Warsaw Pact in the North Atlantic , the GIUK gap and in the European Arctic Ocean was already practiced by NATO in 1957 in Operation Strikeback. Operation Strikeback was the largest peacetime naval operation, with 200 warships, 650 aircraft, and 75,000 people, and assembled the largest fleet since World War II. Together with NATO exercises running at the same time, 250,000 people, 300 ships and 1,500 aircraft were set in motion on a front from Norway to Turkey in order to simulate the war against the Soviet Union. To simulate the REFORGER convoys, more than 200 merchant ships were involved in the exercise, including the Queen Mary and Ile de France , both of which were marked as target ships. After a brilliant "sea battle" in which the two nuclear submarines Seawolf and Nautilus were involved on the "opposing" side and 8,000 marines - who were landed in the Dardanelles after a simulated tactical nuclear weapon deployment in order to recapture them (Operation Deep Water ) -, NATO occupied the Norwegian bases occupied by the “opposing” side with simulated tactical nuclear weapons and was thus able to win the “war”.

The Warsaw Pact conducted exercise Okean in 1970 , the largest naval exercise in the world since World War II. Over 200 ships and several hundred aircraft simulated the war against NATO in the Baltic Sea, the Barents Sea, the Atlantic, Mediterranean, Northern and Pacific, in the Philippine Sea and the Sea of ​​Japan. Bombers flew simulated attacks against Soviet task forces in the Atlantic and Pacific, which were US carrier combat groups . In 1981, amphibious warfare with the landing of troops was rehearsed with Syria . In 1983, in a large naval exercise, in addition to the usual attacks on "US carrier combat groups", combat with convoys was also practiced with 40 Soviet merchant ships .

The Hamburg escorted the Dwight D. Eisenhower

All ships of the NFR-90 were ultimately designed to escort REFORGER convoys across the Atlantic. The Soviet Navy would have tried to sink these convoys by backfire attacks with Raduga Ch-22 and Ch-26 and submarines. As a result, emphasis was placed on combined air and submarine defense, with the main focus being on air defense against mass attacks in regimental strength, for which the Combat Direction System (CDS) of the Sachsen class was developed. After the end of the Cold War , new challenges such as those encountered with Operation Southern Cross became apparent . The increasing proliferation of tactical ballistic missiles with the potential of mass destruction is also one of them. There are now a number of proposals - partly from the Bundeswehr, partly from industry - to further develop the Saxony class:

  • By upgrading the APAR to 4096 modules per area and software updates for the SMART-L, the SM-3 missile could be integrated to destroy targets outside the Earth's atmosphere, for example tactical ballistic missiles or low-flying satellites. The costs - estimated at around 60 million euros for the radar adaptation and around 800 million euros for full qualification - are high. The SMART-L is upgraded with the Extended Long Range software update (ELR). At the end of 2006, the Dutch Navy carried out tests for the location of ballistic missiles with the US Navy using the Tromp and the ELR update.
  • With a software update, the APAR can also be used as an artillery reconnaissance radar to give "counter-battery fire" with the turret. Another APAR software update would enable the gun to fire control against land targets. In this case, it would also make sense to arm the 127/64 Lightweight , which, like the other guns, comes from Oto Melara . The De Zeven Provinciën class already has a 127 mm gun. With the MONARC concept, the German Navy was also researching into the direction of a heavy artillery.

The ships of the Sachsen- class are also used in their original task for air defense by escorting US aircraft carriers. In 2010 the Hessen was used with the carrier Harry S. Truman for interoperability tests. After the results were positive, Hamburg became part of the American aircraft carrier group around the Dwight D. Eisenhower in early 2013 and was responsible for its air defense. This is the first time that a foreign ship has been fully integrated into a US carrier combat group.



The heart of the F124 is the command and weapon deployment system Combat Direction System (CDS). For the first time in the history of the German Navy, this integration is being carried out by industry - the members of ARGE F124 and their sub-suppliers. The computer capacity is distributed over 17 computers that are connected to a multiple redundant ATM bus . The frigate is thus able to capture more than 1000 air targets at the same time. The system was explicitly designed as the German counterpart to the Aegis combat system. Without exception, the system brings together all of the ship's sensors and effectors to form a network, so that air defense, surface combat, submarine hunting, EloKa , navigation and communication are carried out by one computer network. APAR and SMART-L take over the task of AN / SPY-1 D, AN / SPS-67 (V) 3 and three AN / SPG-62 , while the DSQS-24B sonar the task of AN / SQQ-89 ( V) 6 takes over.

The 17 computer cabinets of the CDS, which serve as network nodes for the sensors, effectors, links, etc. via the ATM bus, are also connected to the ATM bus by a bus interface unit (BIU) with each other and to the ship's multi-purpose consoles via a local one Network connected. Each network node consists of a number of SPARC / RISC processor cards . As a result, the computing power is distributed over several CPUs instead of being limited in number and space. An operator can log into any console in order to perform any task. A network node has two tasks: firstly, to adapt the interface and the communication protocol of the incoming raw data to the data processing scheme, and secondly, to execute commands that were specified by the “Computed Software Configuration Items” (CSCI). The CSCI are node-specific, but the computer cabinets can load and start any program. Since the application software does not know from where it is being executed, a dynamic, automatically controlled reallocation of data processing capacity is possible. If a network node fails, the applications are distributed within the framework of the available computer resources and restarted. In order for the process to be possible, the temporary data must be specially saved. The advantage is that if a number of network nodes fail, this has no effect on the performance of the system. However, the high demand for computing power is a disadvantage.

The sensor fusion works with hybrid fusion. While the fusion of the raw data would require too much computing power and a merger of the tracks were lost too much information that is fused to the hybrid fusion as a compromise the track and their associated raw data. In addition, the sensors send non-kinematic data such as identity and IFF. Navigation radar, FL 1800, Target Designation Sight (TDS) and sonar only send tracks. All data is then merged into tracks using multiple hypothesis tracking , adaptive interactive maneuver models and Kalman filtering . Through the Association Point / Bearing process, the angle information is linked to the tracks via a link .

In principle, APAR does not pursue all goals. When a target is located and fused by a sensor, a threat analysis ultimately decides whether the computer sends a target tracking request to APAR. The angle information of the Target Designation Sight (TDS) - it is the multi-sensor platform (MSP) 500, which is operated manually by the operator - always triggers a search query to APAR.

The fused tracks obtained are then subjected to a tactical analysis by the computer, which is divided into the areas of air, surface and submarine. The contacts are now classified by a freely configurable database which contains kinematic and non-kinematic entries. If no clear determination is possible, an IFF request is sent. If a contact is classified, it is passed on to other units via link 11 and link 16 . The following Action Plan Synthesis creates attack plans against targets according to their threat, the doctrine and the available weapons. The plan created in this way can either relate to your own ship or the entire combat group. In the latter case, all available weapons of the combat group are used for attack planning of the system. The battle is conducted in the operations center (OPZ). Around three dozen soldiers use the 17 consoles to create an overall picture of the situation that the commander uses as a basis for decision-making when carrying out his assignment. To be on the safe side, most of the posts in the OPZ are staffed twice.

All frigates of the Sachsen -class are additionally equipped with the MAIGRET from EADS to eavesdrop on enemy communications. The system uses a number of additional antennas to intercept and target signals from 1 MHz to over 1 GHz. An emitter database enables automatic identification. The system can scan 50 channels per second in the high-frequency range, 3300 channels per second in the V / UHF band (each linear, i.e. without frequency hopping ) or up to a billion channels per second in adaptive mode (i.e. with frequency hopping). The heading bearing can be viewed on a PPI or A-scan. The characteristic properties of incoming signals are statistically recorded and evaluated. The results will be fed into the Local Area Network to be merged there.


White areas of the APAR; the rectangular matrix is ​​not (yet) completely filled out. The protruding boxes above are the ESM antennas of the FL 1800 S.

The APAR is an Active Electronically Scanned Array with four fixed antenna surfaces, which is used for fire control and limited volume search. The radar was designed to ward off mass attacks by maneuverable anti-ship missiles with stealth properties. Each antenna surface consists of 3424 transmitter and receiver modules (TRM) based on GaAs, which are arranged in a 64 × 64 matrix as MMIC quad packs. The antenna area is divided into four quadrants and designed for 4096 TRM per area, which can be retrofitted for missile defense in the course of an increase in combat value in order to increase the effective radiation output. As a special feature, the TRMs work very broadband in the 7–13 GHz range, so that the edges of the C and K u bands can also be covered in addition to the X band . Each antenna surface can form more than 500 thin signal lobes per second and swivel them by ± 70 °. The pulse repetition frequency and transmission frequency are continuously adapted to the target, the optimal parameters are calculated for all targets in real time. Detected targets are scanned with special waveforms to detect a missile launch. A non-cooperative target identification through High Range Resolution (HRR) is possible. Since the SM-2 and ESSM missiles are dependent on target lighting on the final approach, the APAR takes on this task. Due to the four quadrants per antenna surface, each can theoretically steer four missiles into targets at the same time. The Interrupted Continuous Wave Illumination method (ICWI) makes it possible to use the antenna in the time-sharing method in order to direct even more missiles into targets at the same time per antenna surface. The APAR also takes over the fire control for the turret. The radar has a displayed range of 150 km and can track 250 air and 150 sea targets at the same time.

FL 1800 S

The FL 1800 is the standard EloKa system of the German Navy; it was developed to repel mass attacks with anti-ship missiles in the Baltic States or in the North Sea. The system consists of four ESM boxes , each of which contains two combined antenna areas. The antenna surfaces cover a frequency range from 0.5 to 18 GHz, with ten spiral antennas available for each band . The system can precisely determine the elevation and azimuth angle to an emitter through the seven computer racks below deck and calculate out the multipath reception. There are four additional antenna surfaces to interfere with the opposing radars, which carry out electronic countermeasures using passive phase-controlled signal cones with eight traveling wave tubes in the frequency range from 7.5 to 18 GHz . Each signal lobe can disrupt a single target or a radar together. The effective radiated power is sufficient to cover the radar cross section (RCS) of the frigate. In addition to hardware improvements and the ability to generate pulsed noise interference, variant S also has a feature for distance estimation based on amplitude, for example to be able to fire RAM missiles in anti-radar ship-to-air mode at anti-ship missiles and aircraft.


SMART-L from Hessen

The SMART-L is a rotating long-range radar with phased array antenna from the former Dutch manufacturer Hollandse Signaalapparaten (Signaal), now Thales Naval Nederland . The radar, which is passive phase-controlled in the elevation angle, was developed specifically to locate stealth aircraft . The antenna with the dimensions of 8.2 m × 4 m consists of 24 rows of receiving modules stacked on top of each other. Of these, 16 rows can both send and receive, the rest can only receive. The radar uses the chirping D-band (1-2 GHz) solid-state transmitter (D-SSTX) on the LW-09 radar to transmit. The transmitter module, made up of 16 units connected in parallel, generates a peak power of 4 kW, which is then amplified in 32 power amplifier modules to 100 kW pulse power. These systems are located in the deck structure under the radar; the signal then travels through a waveguide to the antenna. There it is emitted via digital phase shifters. The phase control of the transmission energy achieves both vertical beam pivoting and antenna stabilization.

Since the SMART-L is supposed to locate stealth targets, the antenna is so sensitive that practically every radar echo contains a Doppler shift . In addition, there is the problem that, in addition to the disturbance data, mainly birds are located at great distances. To avoid overloading the plot extractor with false targets, 1000 air targets, 100 surface targets and 32 jammers can be tracked simultaneously. The target correlation to tracks is carried out from scan to scan via the distance and radial speed of the contact using Multiple Hypothesis Tracking (MHT). The MHT filter calculates all plausible traces of flight on the basis of the contacts, the most likely hypotheses are passed on to the ship's combat system. Once the target position and course have been determined, friend-foe recognition according to STANAG 4182 can be carried out. Since this also takes place in the L-band, no separate antenna is required. If the friend-foe identification is negative, the SMART-L can determine the type of air target through non-cooperative target identification.


The Saxons in the dock. The bow sonar is covered.

The DSQS-24B from Atlas Elektronik, known in-house as ASO 95, is installed as the bug sonar. Modern bow sonars usually have piezo-based sound transducers in polyvinylidene fluoride which, like active electronically scanned arrays, can form and swivel virtual signal beams. The cylinder base of the ASO 95 has a diameter of 1.88 m and can form 32 to 64 virtual signal lobes, which are stabilized against 25 ° rolling and 8 ° pounding by electronic beam pivoting. The antenna covers the frequency range from 2 to 11 kHz when the system is operated purely passively, and 6–9 kHz in active mode, with a bandwidth of 1 kHz then being used for purely passive reception. Two different CW frequencies can be used during a ping . Sending still takes place in the same way. The pulse length can be between 5, 50 or 300 ms. Either CW, FM or a combination of both can be sent, for example 50 ms CW followed by 50 ms FM. The received data from CW and FM are processed in parallel to achieve faster results. The CW component is used to calculate the Doppler effect in order to determine the radial speed of the target, the FM component profiles the target lengthways and thus outputs the course angle and body length of the target. The computer outputs the speed of the target based on course angle and Doppler, and a rating as to whether the contact is a submarine. Several CM50 / FM50 pulses or one CM300 / FM300 pulse are required for this. The transmission modes are: Omnidirectional (ODT), omnidirectional with three active signal cones (TRDT), each with any combination of 5 ms and 50 ms pulses; omnidirectional search in a sector (S-ODT), S-TRDT as a combination of both, and SDT as a sector search for fire control solutions, where only 300 ms pulses are used. Different frequencies are used depending on the target size, required resolution and location range. The problems of active location at high speeds can now be largely neutralized with computer sonar systems.


In addition to the listed primary armament the vessels of the lead axes class two revolver cannon of the type MLG 27 for speedboat Defense, six mark 36 srboc for firing chaff - and infrared missile (by four throwing turbines of the type MASS of Rheinmetall be replaced) and a number of handguns .

Gun turret

76/62 Compact from Hamburg

The OTO Melara 76 mm gun is located on the foredeck in front of the RAM launcher. The weapon 62 caliber lengths verschießt a wide range of ammunition with a cadence of up to 100 / min and a muzzle velocity of 925 m / s. The effective range against ground targets is 16,000 m, against air targets as anti-aircraft guns up to 7,800 m. The gun barrel can be moved 35 ° / s in elevation in a range of + 85 ° / -15 °. The rotation speed of the tower is 60 ° / s. The mass is reduced through the use of light metal, the housing is made of GRP . The small muzzle brake reduces the recoil from 11 t by 10% to 9.9 t, which is absorbed by hydraulics.

The gun works as follows: Below deck is the double loading ring with a capacity of 70 cartridges, which are moved from the outer to the inner ring by the rotary movement of the loading device. On the left-hand side, the cartridges move into a screw conveyor in the rotation axis of the tower, which guides the ammunition vertically upwards. Once at the top, the floors are picked up by pendulum arms. These two pendulum arms swivel alternately (one moves upwards, the other swings downwards) and deliver the cartridge to the feed drum in the tube axis. The cartridge falls onto the loading shell, is attached, the slide rises and the shot can break.

Vertical take-off system

The Sachsen fires an SM-2 from the vertical take-off system

The Raytheon Mark 41 (Mk. 41) was chosen as the vertical take-off system. The system is located behind the RAM launcher and in front of the bridge and consists of 4 × 8 (= 32 cells), which are arranged in two rows on the port and starboard sides. The “cells” consist practically only of a frame with a plenum at the end and a lid at the head. The gas duct, which is also covered to protect against water, is located between the two rows of four of a unit. On the frame, which requires more than two decks, there are three devices: On the top deck a “Launch Sequencer” (LSEQ), which establishes a connection between the ship and the missile and monitors the system status. The “Motor Control Panel” (MCP), which is connected to the LSEQ via Ethernet, is located on the deck below . The MCP controls the flaps and valves as well as the drainage of the plenum. One deck below, at the lower end of the Mk. 41, there are two “Programmable Power Supply” units (PPS), which supply the VLS with energy and are controlled by the LSEQ via Ethernet.

The weapons are delivered in square canisters that are inserted into the vertical take-off system from above and connected to the system using standard 145-pin connectors. The canisters protect the missile from environmental influences and enable the LSEQ to recognize the type of weapon. The starting sequence is as follows: The cover of the cell and the gas duct (uptake) are opened and the drainage valves of the plenum are closed. Then the rocket motor fires, which punctures the canister's tailgate. The missile accelerates and pierces the front cap of the canister. The flaps are then closed and the plenum drain valve opened again.

The 32 cells can be equipped with surface-to-air missiles of the type SM-2 Block IIIA and ESSM. The SM-2 has a range of 167 km and a speed of Mach 3.5. At medium range, ESSMs are fired, which reach a range of 50 km and Mach 4. The ESSM are housed as a quad pack, i.e. four ESSM per cell. Both missiles are dependent on the APAR for target lighting on the final approach, as these are guided by semi-active radar target search. In the course of the study "Capability expansion F124 TBMD", the integration of the SM-3 was found to be feasible. The SM-3 can destroy targets outside the atmosphere, such as tactical ballistic missiles or low-flying satellites. It is planned to replace the ESSM with the modernized version ESSM Block 2 from 2025.

Close-range defense system

RAM launcher on the hangar above the flight control tower, SMART-L in the back

The Close-In Weapon System Mark 31 consists of the missiles RIM-116 Rolling Airframe Missile, which are placed in transport canisters of the type EX-8. The combination is again referred to as EX-44. The rotating launcher with 21 cells of the Mark 49 type consists of the start box and a mount, which was taken over from the Phalanx CIWS and is known as the Mark 144. For the sake of simplicity, the entire system is simply referred to as RAM, after the "Rolling Airframe Missile" missile. The Sachsen class has two RAM starters - one between the gun turret and the vertical take-off system and one on the hangar. The main task of the short-range defense system is to intercept enemy anti-ship missiles.

The RIM-116 missile is based on an old AIM-9 Sidewinder , the viewfinder was taken over from the FIM-92 Stinger . The advantage is the low cost, the disadvantage is the typically short range of older Sidewinder versions, which is only 9 km with the RIM-116. The Mach 3 fast missile has an RF / IR dual viewfinder, which means that the target can be controlled as an anti-radar surface-to-air missile. The RF part is integrated next to the imaging IR viewfinder in the form of four antennas, two of which form “horns” pointing forward. The IR viewfinder in the tip consists of a linear 80-pixel array which, due to the rolling movement of the missile , carries out a rosette scan in flight. In the vicinity of the target, additional guidance is provided by the viewfinder’s intelligent image processing, but shooting is only possible using RF guidance. The RAM missile can be used against both air and ground targets. The advantage is that the ship can fire at an emitter purely passively via the FL 1800 S. The fire-and-forget missile automatically searches for the target after it has been fired; an approach is not necessary.

Anti-ship missile

Two four-starters for RGM-84 Harpoon , which are located between APAR and the funnels, are equipped as anti-ship missiles . The Harpoon is powered by a Teledyne turbojet model J402-CA-400 with a thrust of 3.0  kN and started with a booster that provides an additional thrust of 53 kN over 2.9 seconds. The missile has a WDU-18 / B warhead with 221 kilograms of high explosive. The navigation to the destination is carried out with an inertial navigation system , while the Harpoon navigates around 15 meters above the water to the destination during the approach phase. A kink can be built into the flight path in order to approach the target area from a certain direction. As soon as the missile is within a predetermined distance from the suspected target, it switches on its on-board K u band radar to find the target. Alternatively, the radar can be activated immediately after the start or intermittently. As soon as the target is captured, the missile approaches it at an altitude of 2 to 5 meters until the impact. The warhead does not ignite directly on impact, but with a time delay, so that the explosion takes place inside the ship and causes considerably more damage than a contact-igniting weapon. The range is over 140 km.

Torpedo tubes

Torpedo tubes on the Hessen

The Mark 32 torpedo tube triplets are located amidships level with the funnels , on both port and starboard sides, and are shielded by the superstructure. Through the longitudinal opening in the outer skin, the treble hook can be turned outwards in order to eject torpedoes with compressed air. Depending on the setting, this takes place at 10–126 bar. The tubes of the launcher are made of GRP, the mass of one unit is about one ton. The Sachsen -class carries the MU90 torpedo, which, in addition to being fired from the triplets, can also be dropped from the on-board helicopter.

The MU90 torpedo with a diameter of 323 mm and a length of 2.8 m can achieve speeds of over 50 kn with a range of more than 12 km and over 25 km at 29 kn. The maximum diving depth is over 1000 m. The acoustic viewfinder works at over 10 kHz, consists of 30 piezoelectric sound transducers, can form several transmit and receive lobes at the same time like an active electronically scanned array and search actively and passively at the same time. In a space of 120 ° in azimuth and 70 ° in elevation, 33 reception lobes are formed, 15 of which receive four frequencies simultaneously. Together with 47 transmission lobes, which transmit with FM, CW, BSK and BPSK , up to ten targets can be pursued simultaneously if the acoustic counter-counter-measure properties (ACCM) are good. The viewfinder also looks down to sound out the bottom and can also capture small submarines that are pounding. The 32 kg shaped charge uses insensitive explosives and is detonated on impact. The Pumpjet is powered by silver oxide aluminum batteries with seawater and a low-noise, brushless Permasyn motor. The power control of the battery is based on the energy requirement of the motor and is adjusted via an electronic lye management.



With a bundle of measures, the stability of the Saxony class was increased, which describes the ability of the ship to remain buoyant even after damage and to continue the battle if possible. In addition to a signature reduction, in which the superstructures are alternately inclined towards the water surface (X-shape) in order to reduce the radar signature , the concept of modularization of the MEKO series has now also been extended to ventilation and air conditioning: there is a departmental self-sufficiency for spray water , Fire extinguishing and electrical energy supply systems as well as other ship operating systems available. On the F124, the structural stability is significantly improved by six double transverse bulkheads (at the level of the bridge / VLS, bridge / APAR, APAR / Harpoon, chimneys, in front of SMART-L, hangar / helipad) and three box girders running in the fore and aft direction. The box girders go level with the upper deck from the VLS to the helipad on the port and starboard sides of the ship and in the middle of the hull. These additional stiffeners and coffer dams mean that the gas hammer and the fragmentation cloud can only expand to a limited extent in the ship after a shell or missile impact and that the longitudinal strength is maintained. In this way, the hull can largely be prevented from breaking apart.

Department-independent sea water fire extinguishing, automation, ventilation and electrical distribution systems are further features of the F124. The departmental self-sufficiency leads to a change from the horizontal laying of pipelines and cable trays in the ship over several departments with numerous bulkhead openings to vertical arrangement with central risers, air and cable ducts in each department. In the event of damage, only one or two departments are down, the other departments, including ventilation, remain intact. The possible horizontal spread of smoke and heat through the ventilation system is largely eliminated. Combating damage is therefore less hindered, and the ship and crew remain operational for longer.

The coordination of measures to combat damage and impacts occurs with the support of the "Integrated Monitoring and Control System" (IMCS) from the ship's technical control center and associated command posts distributed on board. The new IMCS is a data bus-based automation system, via which all ship technical systems and facilities on board are monitored and operated with the help of around 7000 measuring points distributed throughout the ship. This system also has extensive operator assistance and a fully automatic damage analysis in the event of malfunctions and damage. This enables the commander to see the technical status, performance and availability of individual sub-systems at any time. In addition, automatically generated "kill cards" also indicate possible consequences of the loss of performance and / or availability. All conceivable operating and damage scenarios can be simulated in the system for training purposes for the crew.

Propulsion system

The Hessen collects fuel from the carrier Dwight D. Eisenhower

The drive is a combination of two diesel engines and a gas turbine as a CODAG drive . A GE 7-LM2500 gas turbine from General Electric and two drive diesel engines 20 V 1163 TB93 with 7,400 kW each from MTU act on the two shafts with variable-pitch propellers via a cross-connect gearbox from Renk . Thus a total output of 38,000 kW is available. The drive diesels with a mass of 22.8 tons each, a displacement of 232.7 liters and a consumption of 1998.8 L / h at nominal load are located next to each other between the shafts and feed the respective main gearbox further forward. The drive works as follows: The torque of the diesel engine is introduced into the starboard or port side main gear via two flexible couplings one behind the other. There the power is delivered via a fluid coupling and through a gearbox to a two-stage gearbox with 2 gears, the transfer case of the gas turbine also delivering its torque to the second shaft of the reduction gear. The output gear of the reduction gear is in turn connected to the propeller shaft. The gas turbine with a nominal output of 25 MW without inlet and outlet losses generates a pressure ratio of 18: 1 with a 16-stage compressor. After the annular combustion chamber, there is a two-stage air-cooled turbine that drives the compressor. This is followed by a six-stage turbine, which generates the drive power in the form of torque. The turbine weighs around 22 t including elastic bearings, the consumption is around 0.227 kg / kWh. The shaft of the gas turbine transmits the torque to the transfer case of the gas turbine, which drives a reduction gear with an overrunning clutch , the gears of which are connected to the gear of the reduction gear of the main gear on the port and starboard side via membrane and friction clutches. In contrast to the propulsion systems of the predecessor ships of the Brandenburg class , this configuration not only saves a gas turbine, but also achieves cruising speed more economically with just one diesel engine, which lowers life cycle costs.

To what extent the acoustic signature of the diesel engines was reduced is unknown. Presumably, in keeping with the times, the diesel engines are mounted with double elasticity and are surrounded by a sound capsule. Between the shafts behind the drive diesels there are two more Deutz 16/628 diesel engines with 1 MW each for power generation on board, which are supplemented by two more behind the gas turbine. The Saxony class is qualified for sea ​​supply ; the fuel is taken over through refueling openings on the structure of the front RAM starter.

Board helicopter

Flight deck of the Hessen

As with the frigates of Bremen - and Brandenburg class, the two serve aboard helicopters of attacking sea targets, which are outside the weapon range of the frigate itself and for submarine hunting . Two Sea Lynx helicopters are carried. The on-board helicopters are automatically moved from the helipad to the hangar and vice versa with the help of an on-board helicopter moving system . The on-board helicopters can be armed with four light anti-ship missiles of the Sea Skua type ; Two modern MU-90 torpedoes can be carried for submarine hunting. In contrast to the Bremen and Brandenburg class, the MH90, which is the sea-based version of the NH90 , fits into the hangar of the Saxony class, but the hangar doors would have to be enlarged. To start flight operations, the flight deck railing must be folded down and the flight control tower must be occupied. During the submarine hunt, one Sea Lynx carries the diving sonar ("Dipper"), while the other is ready with torpedoes ("Pony"). There is no fixed deployment scheme in the anti-ship role.

Ship list

In total, only three units were procured, the option of a fourth ship was not taken. The unit price is around 700 million euros.

Identifier Surname Callsign shipyard Keel laying Launch delivery Commissioning home port
F 219 Saxony DRAA Blohm + Voss , Hamburg February 1, 1999 January 20, 2001 November 29, 2002 November 4, 2004 Wilhelmshaven
F 220 Hamburg DRAB Howaldtswerke-Deutsche Werft , Kiel September 1, 2000 August 16, 2002 September 2004 December 13, 2004
F 221 Hesse DRAC North Sea Works , Emden September 14, 2001 July 26, 2003 December 7, 2005 April 21, 2006
(F 222) Thuringia Option not taken

Web links

Commons : Saxony class  - collection of images, videos and audio files


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