The big sister - U212A 2nd batch

Capability gain or expansion of existing capabilities in the execution of submarine operations

The U212A 1st batch submarines have now been in service for over ten years and are still the most modern conventional submarines in the world. Air independent propulsion (AIP), impressive sensor technology, a high degree of automation and extensive integration of the command and weapon deployment system (FüWeS) are the key characteristics of this type of submarine.

The long sea endurance allows largely self-sufficient and remote operation, and with the DM2A4 heavyweight torpedo the Submarine equipped with one of the most modern weapons against surface and underwater targets currently available on the global market. In addition to these technical details, the design of the first batch U212A The new submarine class fulfils the highest operational requirements and continues to set standards in conventional submarine construction. The compact design and comprehensive signature reduction predestine the boats in this class for operations in shallow waters and for covert operations.

The decision to increase the number of available units is based on the needs of the navy. The two new units are necessary in order to be able to fulfil the numerous tasks within the framework of national obligations and operations within the Alliance. With the realisation approval U212A 2nd lot of 30 May 2006 was accompanied by the decision to change the design of the U212A and adapt it to current requirements.

The boats of the second batch (U35 and U36) are currently being added. The following section describes how these new units differ from their "little" sisters and what opportunities and consequences result from this.

Key elements of the "new" design are:

• increased mobility,
• significant changes in the sensor technology and in the command and weapon deployment system (FüWES),
• drastic changes in the area of communication,
• an increased ability to support Special Operation Forces (SOF),
• the completely redesigned extension unit configuration,
• a new steering position, and
• a pre-swirl rudder that optimises the propeller wake.

The characteristic features for the entire boat class U212A (such as AIP and signature poverty) remain largely unchanged.

Operational mobility

Christening of U 35, the 5th boat of this class for the German Navy at HDW in Kiel (Photo: PIZ)

Even if this feature may appear to be of secondary importance at first glance, increasing the operational mobility of the boats in the second batch is a key aspect. The significantly increased fuel supply means increased deployability and a much greater radius of action. This not only makes it more difficult for a potential adversary to predict the potential deployment area of the boats, but also allows the creation of a strategic overweight with a corresponding early deployment order, which can be of decisive importance for initial operations in particular. Enemy Anti Submarine Warfare (ASW) units are thus tied up for much longer and have to monitor a much larger area, which at the same time leads to wear and tear on these forces in terms of endurance and alertness. Of course, this does not mean that the boats of the 1st batch are not capable of achieving comparable strategic and/or operational effects, but the reduced operational mobility goes hand in hand with the need for earlier deployment decisions and operational planning. U212A 2. lot can thus increase the flexibility for political and strategic decision-making processes.

The accompanying tropicalisation on the boats of the second batch, which is achieved by a more powerful air conditioning system, is only stringent. It emphasises the worldwide operational capability of the weapon system Submarine U212Awhich has already been impressively demonstrated by the boats of the first batch on the east coast of the United States.

New boat - new sensors

The Flank Array Sonar (FAS) and the Towed Array Sonar (TAS) form the core of the acoustic sensor configuration in the boats of the first batch with the Cylindrical Array Sonar.

The boats in the second batch are the first to use an Enhanced Flank Array Sonar (EFAS), which has already delivered promising results in the initial tests. Compared to the FAS of the first batch, the EFAS has a significantly increased antenna length, which significantly increases the sensitivity of this sensor and the sonar system as a whole. Experience from future deployments and exercises will show whether the EFAS will be able to replace the non-equipped TAS. Should the need arise to retrofit the TAS, the technical possibilities for this are provided ("not equipped but fitted for").

In addition, the active sonar on the boats in the second batch is from the Submarines of the U206A class. This means that U212A 2nd batch has an active component that is not shown on the boats of the first batch. The active sonar is not a classic submarine sensor in view of the covert mode of operation, but it provides reliable target data in a very short time in submarine hunting scenarios and can be used in combat with very modern, silent Submarines be a decisive advantage.

There are also changes to the periscopes in that one periscope is replaced by an optronic mast, which in turn is complemented by a periscope. This is the first time that an optronic mast has been used on German Submarines which can be seen as a kind of departure from the usual periscope tradition. The main difference is the fully electronic image transmission, which makes a conventional pressure body feed-through obsolete. The experience of partner nations proves the impressive effectiveness of this sensor.

The high-quality periscopes, which are scaffolded on the first batch, will be retained by mutual agreement between the BAAINBw and the Navy until further notice. Whether they are to be replaced by optronic masts in the long term will depend on the German Navy's experience with this sensor.

In addition to these changes to the sensor configuration, the operational centrepiece of the Submarine a different decision was made compared to the boats in the first batch. The FüWES ISUS 90-40 as an integrated sonar and weapon control system "marries" the information from navigation, radar, the EloUM system, the periscope and optronics, the integrated radio communication system, the torpedo system and the sonar and makes it available to the maximum of eight operators. The ISUS 90 thus offers complete integration of position and weapon information, which is based on the proven principle of the SLW83 on the U206A boats.

The decision in favour of the FüWES ISUS 90-40 should not be an abandonment of the excellent and proven German-Norwegian cooperation with regard to the operation of the Kongsberg system in the first batch. Here, too, it will have to be decided in future which system should be given priority.

As a positive side effect of this situation, the submarine training centre in Eckernförde now has the opportunity to train submarine crews at both facilities, which meets the great interest from the international environment in high-quality training.

Improved telecommunications connection

In the area of command and control capability, the two boats in the second batch took the logical step of further development and, with the installation of SHF SATCOM capability, global command and control capability was guaranteed with the connection to IP-based services and the transmission of high-bandwidth data. This enables participation in networked operations management and takes account of the increased need for information exchange among military and political leaders. It remains to be seen to what extent the capacities of the German armed forces with regard to SHF satellite communication will also fulfil the needs of the military and political leadership. Submarines can be made accessible. Whether a corresponding capability adjustment of the Submarines of the first batch remains questionable in view of the investment costs. The ability to participate in IP-based services such as NSWAN and JCHAT is crucial for future multinational operations.

Another key distinguishing feature compared to the Submarines of the first lot is the CALLISTO telecommunications buoy, which enables communication from the depths. The CALLISTO specifications include a specially customised telecommunications spectrum and represent an ambitious project overall. CALLISTO still has to prove its operational readiness.

Furthermore, the Submarines of the second lot for the first time a LINK authorisation, which for German Submarines is also a novelty. By utilising the Tactical Data Link System (TDLS), the data rate is increased while the communication time is reduced at the same time. This fulfils today's higher requirements for integration into tactical data links. By using the TDLS, it is possible to participate in a standardised exchange of information across armed forces within a closed unit. In addition to interoperability between the different branches of the armed forces, the focus is also on cooperation between the different armed forces in NATO and EU-led operations.

The integration of a Submarine into a LINK network will pose an interesting challenge in terms of information processing on board and the provision of relevant information, as it will hardly be possible to clean up the situation picture by screening and vetting the telecommunications traffic beforehand. However, against the background of far-reaching sub-hunting sensors and the development towards a three-dimensional ASW network, this connection compensates for the existing deficits with regard to a far-reaching and timely exchange of situational awareness and can thus establish itself as a key capability for this network.

Diver's lock

The sixth boat in the 212A class is christened at the HDW shipyard in Kiel - the sponsor city is Plauen. (Picture: PIZ)

The Submarines U212A Lot 2 will have a diver lock for the embarkation and disembarkation of up to four special forces soldiers. The diver lock will be a significant improvement for the covert transfer of special forces. Until now, it has only been possible to transfer these forces via the torpedo tubes, which places considerable restrictions on the equipment these forces can carry. For the equipment of the special forces, therefore U212A 2. a set of transport containers accessible from the outside, which are intended to cover the need for additional space for material and equipment. Apart from the aspect of mission optimisation, which the diver lock will undoubtedly bring with it, the lock also opens up more intensive cooperation with allied special forces that do not have the "torpedo tube" method in their portfolio. Against the background of increasing co-operation in the area of special forces and in particular due to the high level of agility even at shallow water depths U212A 2. Los thus offers a very attractive option for intensive co-operation with the special forces of allied partners.

Summary and evaluation

Even if the changes to the second batch are hardly recognisable from the outside (1.2 m longer turret structure and pressure hull), the boats in this batch represent a stringent and consistent development step. The experience gained from operating the boats U212A 1st lot were consistently implemented. In addition, the design of the second lot contains sustainable development prospects.

The positive effects resulting from the increased operational mobility are reflected in the improved relocatability of the Submarines to distant regions and therefore less logistical effort for deployments and manoeuvres over long periods and distances. This independence simplifies operational planning and increases flexibility during deployment. Even if relocation is still associated with the Submarines typical speeds, this feature may make it possible to dispense with time-consuming and complicated re-supplies.

The consistent further development of U212A is also evident in the significantly improved telecommunications configuration such as SHF SATCOM and the TDLS connection. The exchange of information between the unit commander and the deployed unit is significantly improved, as SHF SATCOM enables rapid data transmission with a simultaneous reduction in vulnerable times at periscope depth. This "real-time capability" can be decisive for the execution of military operations, particularly for reconnaissance operations and when supporting special forces. The connection of the submarine to TDLS will be a key factor in the establishment of three-dimensional ASW networks in order to ensure the exchange of extensive and complex situation pictures.

With all this positive assessment, however, it must be borne in mind that the human resources on board Submarines remain limited in the future. In order to counteract information overload for the crew, the sender of the information must be aware of the relevance of the message for the commander and the command personnel on the ground. It remains to be seen to what extent the high expectations of the optronic mast will be met and whether this will allow tactical procedures to be adapted for the use of the periscope. The experiences of the alliance partners have so far been promising and unanimously positive.

With regard to the ability of the CALLISTO telecommunication buoy to communicate from the depths, it remains to be seen how this technologically sophisticated approach will prove itself in operation. It must be experienced in the truest sense of the word; this explicitly includes possibilities and limitations.

The integration of the ISUS as described promises many advantages over the first batch. However, the Kongsberg system has proven to be extremely robust and reliable in recent years. Over the next few years, parallel operation of the two systems will allow direct comparisons to be made in terms of operation, performance and stability.

The fitting of the diver's lock is very promising. It significantly simplifies the covert deployment and reception of special forces and considerably increases the possibility of multinational cooperation. Even though most special forces missions have so far been carried out under exclusively national command, a clear trend towards cooperation is nevertheless recognisable. The exclusive combat swimmer role with the torpedo tube as a means of transport places the highest demands on the training and experience of the special forces in order to minimise the risks of this procedure. In addition, the space available limits the special forces' ability to carry material and equipment. These restrictions are compensated for by the diver lock and the transport container. In connection with the increased operational mobility, this aspect in particular provides a highly interesting option for action.

Overall, the project U212A stringently planned and implemented: Major risks in terms of armament technology were avoided, and systems that have been tried and tested for over ten years were used for the most part. As a result, U35 was the first boat of the second batch to go into operation without any major delays or problems - something that is not a matter of course when looking at other defence projects of this size.

In addition, systems and equipment were adapted and made fit for the future where current and future deployment scenarios require it. The key aspects here are command and control capability and mobility - significant progress has been made in both areas without any major risks, which more than does justice to the "age difference" between the boats in the first and second batches.

The development step that began with the boats in the U212A 2nd lot is stringent and logical. Consequently, the expectations for this system are high. It is not only the submarine community that is eagerly awaiting the first operational experience reports from its big sister.

Author: Tim Hullmann

Corvette Captain Tim Hullmann is a member of the Naval Command in the Planning/Concept Department, Head of Undersea Warfare - USK