Submarines of the 210mod Class
A new Development of the Submarine Division of ThyssenKrupp
Marine Systems for the International Submarine Market

Hans Karr

A lready in the mid 1970s was an agreement reached between the NATO partners Norway and the Federal Republic of Germany on the cooperation in a submarine project to be jointly developed. These subs were to be employed at NATO’s maritime northern flank that is west of Norway . While Norway indeed implemented the project with the construction of six boats of the ULA Class (Project 6071, Shipyard “Nordseewerke Emden“; commissioning from 1989 to 1992), the project which was already designated Class 210 by the German side was not realized. In the course of the definition phase it turned out that the requirements of the two navies were not possible to be harmonized. While the specific Norwegian operations requirements were based on the coastal waters characterized by the many fjords, the German Navy had to consider a considerably longer approach route to the planned area of operations. The ULA Class with its approximately 1,100 tons of displacement did thus not satisfy the German requirements.
A concept phase of the Germany Navy for an enlarged follow-on project, the Class 211, which succeeded this cooperation ended in mid 1987 already. The cause for breaking off the project was the tight budgetary situation. This, however, lead to an early engagement with the already planned Class 212 whose special feature was to be the air-independent propulsion in form of the fuel cell. But this procurement project was, for the time being, implemented only sluggishly and postponed several times, inter alias also for financial reasons. Only in October 2005 were the first boats of the Class 212A, the “U31” and “U32” commissioned, after the Italian Navy had, at the beginning of 1996, also decided in favour of this type of submarine with a displacement of approximately 1,450 tons. The “U 33” and “U 34” subs followed in June 2006 and May 2007. In the meantime, a second modified batch of this class comprising two units has been ordered. Their delivery is expected in the years 2012 and 2013. With the introduction of the Class 212A, the German Navy has now at its disposal not only very advanced, but also extremely sophisticated platforms equipped with innovative technology.
Although it was originally a “pet project” of the Cold War and designed for other scenarios, the Class 212A submarines nevertheless optimally cover with their sensors and effectors the bulk of the mission spectrum required of the Navy today. Within the scope of conflict prevention they contribute thus significantly to the fight against international terrorism and crisis management. But the Class 212A shows also very clearly the trends in the construction of conventional submarines that can be observed all over the worlds:

Increasing size
With its improvement in performance it is getting a more sophisticated technology
Concomitantly with that a cost increase both in the construction and in the subsequent operation.
Submarines are mobile, sustainable, and efficient weapon systems with a high survivability and long seagoing endurance. Just the suspicion that submarines might be present in the area triggers off countermeasures already. Submarines thus contain enemy forces and deny the unhampered use of sea areas or sea lines of communication.

Originally the engagement of surface and underwater targets and mine-laying were the main tasks of submarines, today the main emphasis is placed on other things. Due to their low detectability submarines are particularly suited for covert operations in collecting information, for surveillance, reconnaissance, the delivery of frogmen, the preparation of amphibian missions and mine detection. Peacekeeping measures from sea, engagement of shore targets as well as specialized missions are additional special capabilities. New weapon systems, which are currently under development, will make it possible to also engage air targets in future.
It is thus not astonishing that this type of ship has internationally still a high priority in procurement measures. Quite some countries in the Arabian area and in Southeast Asia are planning the new build-up of a submarine component. At the same time, many navies find themselves compelled to replace their older units by new constructions or to modernize the existing boats. Budgetary constraints often inhibit or prevent the implementation of such projects, however.

New Development on a well-tried Basis

The Submarine Division of “ThyssenKrupp Marine Systems AG” (TKMS) under the lead management of the “Howaldtswerke-Deutsche Werft GmbH” (HDW) offers a future-oriented solution with the Class 210mod for especially the target group of newcomers as well as for navies, which are not able to implement complex submarine classes for budgetary reasons and also as an alternative to an expensive modernization. The Class 210mod, a designation meanwhile officially acknowledged by the Fed­eral Ministry of Defence, is based as a further development on the aforementioned Norwegian ULA Class. It is a compact conventional diesel electric submarine with excellent manoeuvre characteristics, heavy armament, and performance capacities for both the old and new naval warfare scenarios.
On the one hand the concept considers a steadily increasing shifting of submarine mis­sion scenarios to the navigable, but difficult coastal waters with their partly extremely shallow water depths, but on the other hand the Class 210mod is also possible to be employed in conventional submarine scenarios outside of littoral waters. With regard to the geographical operational area this Class is equally suited for both the use in temperate and tropical climatic zones. The preparatory work for the definition phase of the Class 210mod is presently carried out collaboratively at the locations in Kiel , Emden , and Malmoe/Sweden. After its completion the boat is then said to be ready for tendering in 2008. The goals of the Class 210mod design are as follows:

Compact conventional submarine with diesel electric propulsion
Preferred exploitation of already tested and known concepts and systems
Consideration of customer experiences
Alternative to complex and expensive modernization of existing submarines.

The design of the Class 210mod is to stand up to international competition from both the East (RUBIN, AMUR 950) and the West (DCNS, SMX 23). As to this, the performance data need not to be afraid of a comparison, not even with modern versions of the Class 209.

In conformity to the design philosophy of Professor Gabler to build the boat as small as possible, the Class 210mod is laid out as a single-hull submarine. With a length of about 56 m and a pressure hull diameter of 5.30 m the ship displaces about 1,000 tons. It is thus clearly smaller than the other currently offered domestic and foreign submarine classes. HY-80 steel will be the shipbuilding material to be used for the pressure hull.
With a two-watch system only 15 persons are necessary as a crew. “Warm bunks”, that is the alternate occupancy by several persons of one sleeping berth, can be avoided here. More accommodations exist for additional personnel. If the crew strength is increased to 21 personnel, the boat can also be run in a three-watch system. The planned employment endurance is 30 days. Automation is used only in those cases where it is really conducive and leads to a saving of crew personnel. Comfort functions are being dispensed with.
A variant of the Siemens-Permasyn motor of the Class 212A serves as an electric propulsion system for cruising. This permanent magnet-energized synchronous motor was particularly designed as propulsion for submarines. Its out­standing features are, among other things, a very low noise level, high-efficiency, lightweight, high availability, high shock resistance, compact design, and low maintenance. The electric motor gets its electric energy from the battery, which also supplies the boat’s power system. It consists of two partial batteries with 216 cells each. Charging is done by two upgraded MTU diesel engines of the 12V 396 types, which power one charging aggregate each. In combination with the generator of the Piller Company it is possible to realize a higher charging capacity than on the older 209 Class subs with four diesels.
As this compact submarine is particularly employable in coastal areas, the proven X-rudder configuration was chosen for a high manoeuvrability. The rudders are laid out in a way that they press a preswirl on the propeller inflow which homogenizes the wake flow field and increases the propeller efficiency on the one hand and reduces the noise signature on the other hand. The propelling power is provided by a Skewback propeller whose extremely low rotation speed prevents cavity and which generates thrust silently even at high speeds.

The Class 210mod is equipped with eight 533mm torpedo tubes. The missile launch and mine laying capability is feasible if so requested by customers. Six weapons of which four are in a quick reloading position can be carried along as reserves. The loading is performed in the harbour via the two upper tubes. The distribution to the individual tubes and to the reloading system will then be made inside the boat.
Commensurate with Class 212A the sail is kept small in order to achieve a low target di­mension with optimised values of resistance. Glass fibre material is being used for coating the sail. A two-men airlock hatch for the delivery of Special Forces is available in the sail access hatch. Planned as hoistable equipment are periscope, snorkel, radar, and communication masts. There is sufficient extra space for additional devices. Communication means and sensors are primary equipment components within the scope of network enabled warfare. The boat has therefore modern base functionalities of today’s state of technology in the field of communication and navigation as well as an advanced combat direction system. The sonar equipment planned for in the basic design in­cludes a circular base, intercept sonar, passive ranging sonar and own noise analysis. A flank array and an obstacle avoidance sonar can be integrated as an option.

Summary

The Class 210mod is a compact, seaworthy submarine with proven technologies. It has low crew strength and can be employed in a two-or three-watch system. With the aid of the enormous experience of the Submarine Division of TKMS a new submarine type has now been made available with the Class 210mod, which meets the demands of present and future operational requirements. The Class 210mod is a future-oriented solution for navies all over the world, especially for newcomers and as an alternative to expensive modernization measures of older submarines. In addition to the modern Class 214, the portfolio of the TKMS Submarine Division is rounded down with a further contemporary and modern submarine type, the Class 210mod.    
         

By Hans Karr, as a free journalist.