Submarine class 212 A

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Italian boat Salvatore Todaro
Class details German Navy Marina Militare Sjøforsvaret
Submarine type Conventional hunting submarine
construction time Since 2003
Number of units GermanyGermany Germany : 8 planned, 6 of which are in service.

(As of February 2017) Italy : 8 planned, of which 4 in service (as of November 2018)
ItalyItaly 

NorwayNorway Norway : 4 planned.

(As of February 2017)

Technical specifications
length 56 m
width 7 m
Draft (surfaced) 6 m
Height above tower 11.5 m
displacement 1450 t surfaced
1830 t submerged
drive Electric motor (1700 kW)
diesel generator (1050 kW)
fuel cells (306 kW)
battery system
speed 12 kn surfaced (≈ 22 km / h)
20 kn submerged (≈ 37 km / h)
Diving depth ≤ 400 m,
destruction diving depth ≈ 700 m
crew 28
Armament 6 × 533 mm torpedo tube
radar Kelvin Hughes 1007 marine radar
Sonar system Atlas Electronics DBQS-40FTC
Electronic warfare
  • EADS Systems & Defense Electronics and Thales Defense FL1800U
  • Torpedo Defense System (TCM) HDW / WASS (Whitehead Alenia Sistemi Subacquei) C303 / S with 40 decoys

The class 212 A submarines are the most modern submarines of the German Navy and the Italian Marina Militare . They are the first boats in the world that are independent of the outside air whose propulsion system for diving trips is based on fuel cells . Because of this propulsion system, the submarines, together with those of export class 214, are considered to be the quietest in the world. They are the only submarines in the German Navy since the last class 206 A submarines were decommissioned in March 2011.

history

Germany

Planning and construction

U 32 at the equipment quay

The tactical-operational demand for boats that are independent of the outside air was already given in the Navy , but failed in the implementation due to technical problems. After the Second World War , nuclear propulsion prevailed as a technical solution in some navies. Until 1980 Germany was restricted in the field of warship development by Protocol No. III on Arms Control of the WEU Treaties .

The class 212 was developed by a working group ( ARGE U 212) of the German companies Howaldtswerke-Deutsche Werft Kiel (HDW) and Nordseewerke Emden (NSWE). A consortium of HDW, Ferrostaal and IKL undertook attempts to drive with fuel cells independently of the outside air in the early 1980s; the first HDW land test system with 104 kW was built in 1983 in Kiel. In 1986 a test facility with the same performance was installed on board the U 1 and tested from 1988.

In the same year, the German Navy undertook to cooperate with Norway to install a Norwegian integrated computer guidance system on its new class 211 submarine . In the spring of 1987, this class was canceled and therefore the plans for the successor class 212 were brought forward, for which the tactical requirements were then determined in December 1987. Components already developed for the 211 class and the contract with Norway were adopted for the new class. The military-economic-technical requirement (MWTF) was established in May 1994, and the construction contract for four class 212 boats was signed on July 6, 1994 between the Federal Office for Defense Technology and Procurement and ARGE U 212. After Italy joined the program in 1996 , the draft was revised to meet the Italian requirements and the class was renamed 212 A. A class 212 boat (without A) has never existed. The changes to the design mainly affect the greater depth of the boats.

During the development of the 212 A class, there were synergy effects with the development of Dolphin class submarines , which has been ongoing since 1986 , and which were intended for the Israeli Navy . Not only could the shipyards be used to capacity until the class 212 A was built, but individual components for the future class could also be tested. There were also synergy effects for the German vehicle industry, which had great hopes for the fuel cell (→ fuel cell vehicle ).

The start of production for the type boat began on July 1, 1998 when the former Federal Minister of Defense Volker Rühe switched on the frame welding machine . U 31 was baptized on March 20, 2002. The proof of operation began in August 2002 in the port and from April 2003 at sea. Testing began in March 2004 with the German Navy. U 31 forms the first construction lot with three other boats of the class ( U 32 , U 33 and U 34 ) . The development of the class cost Germany around 150 million euros, the construction of the four boats for the German Navy a good 400 million euros each.

In order to be able to measure the magnetic signatures of the new, larger boats and thus ensure their difficult magnetic response behavior to magnetic sea ​​mines , a new geomagnetic field simulator was built from 2001 to November 2005 in Borgstedter Enge for around 40 million euros .

On April 25, 2006, U 32 set a new record for non-nuclear powered submarines with two weeks of uninterrupted diving without snorkeling. This happened during a relocation from Eckernförde to Rota in Spain.

On September 22, 2006, the Federal Office for Defense Technology and Procurement ordered another lot consisting of two class 212 A boats, the delivery of which was planned for 2012 and 2013 respectively. Originally the second lot should also consist of four boats. In the future, the German Navy will need twelve boats of the class in order to fulfill their operational tasks and to replace the predecessor boats that were decommissioned in 2011. The boats in the second batch have a unit price of around EUR 500 million. The armaments concept adopted in October 2011 as part of the realignment of the Bundeswehr confirmed that there will be no further new acquisitions.

On February 3, 2017 a cooperation with Norway was announced. Thereafter, both countries together procure six submarines based on the Class 212 A, two of which are intended for the German Navy.

Modifications

The somewhat longer U 35 with the bulkier tower cladding of the second construction section on land next to the original U 33 design in the water

The second construction lot for the German Navy does not show any profound structural changes compared to the first four boats, but these boats received modifications. The capabilities for worldwide operations, for the use of special units and for covert reconnaissance have been expanded . For this purpose, a new Indra satellite communication system ( X-band ) with an output of 128 kB / s for voice or data transmission in periscope depth was integrated. The computer systems have been improved; instead of the Kongsberg MSI-90U mission control system, Atlas Elektronik's integrated underwater sensor system is used. The sonar was revised (replacement of the flank base with a planar antenna), one of the periscopes was replaced by an OMS-100 optronics mast from Carl Zeiss with a SERO-400 periscope, a four-man lock for combat swimmers was installed and the air conditioning system is designed for use in the tropics. The centerpiece of the improved communication capabilities is the Callisto antenna buoy from Gabler Maschinenbau , which, attached to the top of an extending mast, serves as a normal antenna system. Unplugged from the towing cable, it allows the submerged boat to communicate terrestrially and with satellites on all frequency bands .

Since the boats that will be procured together with Norway are to be identical, some modifications will also be made in the third construction lot for the German Navy. For reasons of industrial policy, Norwegian companies will also receive shares in the manufacture of the boats.

Italy

After Italy got into the until then exclusively German project in 1996, a construction lot of two class 212 A boats was realized for the Italian Navy. The executing shipyard was Fincantieri in La Spezia , the fuel cell system came directly from HDW. The two boats are called Todaro and Scirè and differ slightly from the German boats in that Italian suppliers are taken into account, for example with the extension devices and the steering position. The great diving depth of class 212 A is based on Italian requirements in the development phase. There was an option for two more boats, which the Italian Navy had built. The delivery should be completed in 2016, but the second unit was not yet put into service until February 5, 2017. The modifications for the second lot of the German Navy, which are primarily intended to improve the capabilities for international missions, will not be received by the Italian boats. Technically, the boats of the second Italian construction lot almost match the boats of the first construction lot in both countries. With the arrival of the two new units, the two older ones - Salvatore Pelosi and Giuliano Prini  - of the four Sauro- class submarines still in service will be taken out of service. Due to the high level of commitment, the Navy is also working on the procurement of four more boats of the improved NFS ( Near Future Submarine ) variant , some of the systems of which will come from Italian companies.

Norway

On February 3, 2017, a cooperation between Germany and Norway was announced. This provides for the joint procurement of six submarines based on class 212 A by Norway and Germany, four of which are intended for Norway and are to replace the older boats of the Ula class there . However, the boats will have modifications compared to the other boats in the class. There will also be cooperation in training, maintenance and the procurement of spare parts. For this purpose, one in October 2017 joint venture of the companies ThyssenKrupp , its subsidiary Atlas Elektronik and Kongsberg established, at which the two companies ThyssenKrupp and Kongsberg each hold 50%. The name of the company is kta naval systems . The aim is to jointly develop class 212 CD submarines, where CD stands for Common Design.

technology

Hull of a 212 A.

The overall concept of the class brings together the characteristics of the German post-war submarines of the class 206 with those of the - in the meantime built - larger export submarines of German shipyards.

Elements of the Nordseewerke type TR 1700 are decisive . Like this, the ship is considerably larger than previous German boats and allows two decks in the front area. The control center of the boat is thus free of disruptive "through traffic" when in use. The comfort for the crew was also increased by the larger space available; For the first time there are two wet rooms (each with a sink, shower and toilet), dishwasher, microwave oven and multifunctional sports equipment. As in all of the previously built German Navy boats, most of the crew share a bunk .

Class 212 A also complies with the criterion that was decisive for all submarines in the German Navy during the Cold War , namely being able to sail in 17 m water depth in order to pass the shallowest part of the Cadet channel . Compared to those of other navies, the boats are still relatively small.

Development and construction of the class were geared towards the lowest possible noise emissions by means of a constantly running "acoustic management". As with other conventionally powered boats also accounted for boats powered by fuel cells, unlike nuclear submarines heat radiation and pump noise, which at crawl speed makes it difficult to locate passive.

hull

The hull is streamlined with a cylindrical nave and therefore designed for high underwater speed. The organic shape of the tower is more reminiscent of Soviet designs than other western designs. The front subscripts are mounted on the tower. This reduces the flow noise on the hull, which improves sonar conditions. The aft rudders are designed diagonally (as X-rudders ); this has a number of advantages, such as lower water resistance overall, lower minimum water depth when diving and a lower risk of oar damage near the bottom.

Like the older class 206, this type has an outer shell made of non-magnetizable steel . This makes it more difficult to track down the submarine with electromagnetic detectors , and it also makes it safer in mined sea areas. To make it even more difficult to locate it, the boat is planked with a special plastic.

drive

In addition to the conventional system consisting of a lead-acid battery (EnerSys double-decker cells from the EnerSys-Hawker plant in Hagen ) and a diesel generator (engine: MTU 16V396, generator: Piller , 1050 kW), an HDW fuel cell system is installed, which is operated by the Outside air can supply electricity independently. The nine water-cooled polymer electrolyte membrane fuel cell modules are manufactured by Siemens and have a combined output of 306 kW. They are fed with liquid oxygen from pressure tanks and hydrogen from metal hydride storage tanks ; The only waste product is chemically pure water that is used as service water. Both the two cylindrical oxygen tanks and the tubular hydrogen storage tanks are located outside the pressure hull. The cooling water of the fuel cells is used to vaporize the liquid oxygen and drive the hydrogen out of the metal hydrides.

The diesel generator is mounted in double decoupling on a "floating deck" in order to emit as little sound as possible to the hull and above it to the water. The propulsion system allows driving with lead-acid batteries or (surfaced or snorkeling) only with the diesel generator. The fuel cell only acts on the batteries.

The boat is driven in each driving mode via a mounted directly on the propeller shaft, manufactured in Berlin Siemens - synchronous motor 1FR6134 with permanent magnet excitation ( "Permasyn"), which compared to conventional submarine DC machines more compact and lighter fails. The new type of motor is controlled by frequency converters, which are arranged in the form of wedge-shaped modules inside the bell-shaped motor rotor to save space. It can also be continuously regulated through all speed ranges without switching noises and voltage peaks, produces low electromagnetic emissions and little waste heat. Active noise cancellation reduces low-frequency sound. Since the engine delivers more torque in the low speed range than conventional machines, it allows a particularly large and efficient propeller to be used. The seven-bladed sickle propeller should cause particularly low driving noise. As is usual with current propeller designs for submarines, its shape is kept secret; In the photos, the propeller is either covered or a replacement propeller has been installed.

Armament

The main weapon of the boat are torpedoes of the standard caliber 533 mm. These are shot from six torpedo tubes , whereby, in contrast to earlier boats, no drainage pipes, but discharge pipes are used. The torpedo is not started in the tube, but is ejected from the tube with pressurized water and does not start up until a short time later. This prevents the location of the boat when the weapon is fired. The torpedo tubes are, which is unusual, arranged asymmetrically for reasons of space; four tubes are offset to port , two tubes to starboard of the center line.

A total of 13 heavyweight torpedoes of the type DM2A4 hake can be carried. After the shot, the torpedo is directed via an optical fiber (glass fiber) and powered by silver-zinc batteries via an electric motor. Alternatively, up to 24 pipe mines can be carried; two mines each replace a torpedo. Class 212 is the first German post-war class whose pipes can be second-shot according to NATO criteria.

The TAU 2000 decoy ejection system (anti-torpedo submarine) is installed as a torpedo countermeasure. The four discharge containers, each with ten decoys, are located in front of the tower in the free-floating upper ship, i.e. outside the pressure hull. This system is not yet installed in the boats in Lot 1, it was implemented in Lot 2.

The installation of the IDAS weapon system is possible in the future ; This light waveguide-guided light missile can be ejected while submerged and attack air targets such as ASW helicopters or land targets from the surface of the water . A revolver magazine with four IDAS can be loaded into a torpedo tube.

The Italian submarines use the A 184 torpedo as their main armament.

electronics

Several sonar systems are installed as the main sensors (cylinder base, flank base, drag sonar , passive distance measuring sonar, interception sonar for hostile sonar signals, navigation sonar). The complex is referred to as CSU 90 by the manufacturer Atlas Elektronik , and DBQS-40FTC by the German armed forces. Periscopes from Cassidian Optronics (formerly Carl Zeiss Optronics) are installed as optical systems ; The observation telescope SERO 14 is equipped with a thermal imaging camera , GPS antenna and antenna for electronic support measures , the attack telescope SERO 15 with a laser range finder , both with optical range finders. Unlike the previous boats, the optical equipment is suitable for night-time reconnaissance of land targets.

All sensors and weapon systems of the boat are linked by an integrated computer system of the type MSI-90U Mk1 + from the Norwegian manufacturer Kongsberg . In the parlance of the Bundeswehr this is called FüWES (command and weapon deployment system). It is operated via 20 color screens. The boats of the 2nd lot will receive a system from Atlas Elektronik (see section on modifications).

Problems

In January 2015 revealed the mirror details of the classified information classified report from the Navy about the submarine class 212 A. In January 2015 were only U 31 and U 33 ready to use, while U 32 and U 34 were in the yard. U 35 and U 36 were still not in service. With the U 35 and U 36 there were massive problems with the wave system, the drive battery, the radar and the Callisto radio buoy , all of which were not operational. The naval report also notes that the hood on the stove is too small and therefore acrid smoke spreads in the galley as the sausages are roasted. According to the Ministry of Defense, the problems were largely resolved in January 2015.

After an accident on October 22, 2017 in Norway, in which the X-rudder of U 35 was damaged, none of the six boats was operational. As early as July 2017, the U 32 was brought back to Kiel early from a training trip to Norway because the batteries had been damaged on board. Four of the six German submarines were located at ThyssenKrupp Marine Systems in Kiel, including the U 31, which had failed since 2014. Spare parts are missing, there are no reserves. As of November 2018, at least three of the six German submarines were operationally available again. When procuring the boats, the usual spare parts package was dispensed with, which immediately reduced the cost per boat by around 250 to 300 million euros.

In April and May 2018, the U 31 and U 36 were returned to normal service after extensive repairs. For the time being, however, these should not be used on emergency trips, but primarily serve to train staff.

units

Type 212 A of the 1st submarine squadron in Kranzfelder Hafen , Eckernförde
Type 212 A

GermanyGermany (naval war flag) Germany

The boats of the class 212 A of the German Navy were procured in two lots of four and two copies respectively.

Identifier Surname Construction lot Keel laying Launch Commissioning unit Whereabouts
S181 U 31 1. 0July 1, 1998 March 20, 2002 October 19, 2005 1st submarine squadron in Eckernförde active
S182 U 32 1. July 11, 2000 November 2003 October 19, 2005 1st submarine squadron in Eckernförde active
S183 U 33 1. April 30, 2001 August 2004 June 13, 2006 1st submarine squadron in Eckernförde active
S184 U 34 1. December 2001 May 2005 0May 3, 2007 1st submarine squadron in Eckernförde active
S185 U 35 2. August 21, 2007 November 15, 2011 March 23, 2015 1st submarine squadron in Eckernförde active
S186 U 36 2. August 19, 2008 0February 6, 2013 October 10, 2016 1st submarine squadron in Eckernförde active

A third lot with two boats of an improved version is planned.

ItalyItaly (naval war flag) Italy

The boats of the class 212 A of the Marina Militare were procured in two lots of two copies each. A third lot is planned.

Identifier Surname Construction lot Keel laying Launch Commissioning unit Whereabouts
S526 Salvatore Todaro 1. 0July 3, 1999 0November 6, 2003 March 29, 2006 Submarine Forces Command in Taranto active
S527 Sciré 1. July 27, 2000 December 18, 2004 February 19, 2007 Submarine Forces Command in Taranto active
S528 Pietro Venuti 2. 0December 9, 2009 0October 9, 2014 July 6, 2016 Submarine Forces Command in Taranto active
S529 Romeo Romei 2. 04th July 2015 May 11, 2017 Submarine Forces Command in Taranto active

A third and fourth batch of a further developed version of two boats each is planned.

Other classes

Export class 214

The submarine class 214 is intended exclusively for export and goes back to the submarine classes 209 and 212 A. These are conventional hunting submarines with an external air-independent propulsion system, which HDW and shipyards in South Korea, Greece and Turkey have built since 2001.

Class 216

The shipyard HDW has presented its own ideas for a further developed variant under the designation Class 216 , which should have a greater range and a longer duration of use with a boat length almost 40 percent larger than the Class 212. The displacement increases to 2000 or 2200 tons submerged.

The submarines have a permanent crew of 33. Instead of the outdated lead-acid batteries of the previous classes, lithium-ion batteries are used here. ThyssenKrupp Marine Systems offered boats of this class from Australia, but was defeated in the bidding competition by the French state shipyard DCNS Group .

Class 218 SG

For the Navy of Singapore , based on the U 212 A class, the HDW 218 SG class was further developed with a design tailored to customer requirements, of which two boats were also ordered in December 2013. The boats will have an air-independent propulsion system and a tailor-made command and control system that the Singapore-based ST Electronics is developing together with Atlas Elektronik. In May 2017, Singapore ordered two more boats in the class to be built by 2024.

units

The boats of the Invincible class bear, as before units of other classes of ships of the Singapore Navy, some names that were also used by warships of the British Royal Navy , the former colonial power.

The Republic of Singapore Navy uses the prefix RSS, which stands for Republic of Singapore Ship , for all of its ships .

Identifier Surname Keel laying Launch Commissioning unit Whereabouts
S. Invincible February 18, 2019 planned for 2021 under construction
S. Impeccable
S. Illustrious
S. Inimitable

See also

literature

  • Ulrich Gabler: Submarine construction. Fourth edition. Bernard & Graefe, Bonn 1996, ISBN 3-7637-5958-1 .
  • Peter Hauschildt: Fuel cells for class 212A submarines. In: Stephan Huck (Ed.): 100 years of submarines in German navies. Events - technology - mentalities - reception. With the collaboration of Cord Eberspächer et al. Small series of publications on military and naval history , Volume 18. Dr. Dieter Winkler Verlag, 2011, ISBN 978-3-89911-115-6 , pp. 131-139.
  • Eberhard Rössler : The new German submarines. Bernard & Graefe, Bonn 2004, ISBN 3-7637-6258-2 .
  • U33: Until the food runs out . In: Focus , No. 50/2007
  • On a dive trip with U-33 . In: Stern , No. 27/2008

Web links

Commons : Submarine Class 212 A  - Collection of pictures, videos and audio files

Individual evidence

  1. ↑ Holger Naaf: The fuel cell on U 212 A. (PDF, German; 3.0 MB) (PDF) Federal Institute for Hydraulic Engineering, Defense Technical Center for Ships and Naval Weapons Eckernförde, 23 September 2008.
  2. ↑ a b submarine class 212 A. In: marine.de. Federal Ministry of Defense , accessed on August 19, 2013.
  3. ↑ Günther Stiller: The target photo that made a US admiral angry. In: Hamburger Abendblatt of August 8, 2007, accessed on April 5, 2017.
  4. ^ Protocol No. III on arms control. Retrieved February 8, 2013.
  5. ↑ Hans Pommer, Peter Hauschildt, Randolf Teppner, Werner Hartung: Outside air-independent propulsion system for submarines. (PDF; 8.7 MB) In: techforum issue 1 - 2006. ThyssenKrupp, 2006, pp. 65–69 , archived from the original on March 7, 2016 ; accessed on April 16, 2018 . ISSN 1612-2763  
  6. ↑ Hans Pommer: Use of fuel cells and their energy storage for underwater use. ( Memento from April 25, 2005 in the Internet Archive ) (PDF; 1.3 MB) Marine Research 2000 plus, 1st North German Symposium, GEOMAR, Kiel, January 13, 2000
  7. ↑ a b Start of construction of the 1st class 212 submarine. In: Hansa , 1998, No. 9, p. 216
  8. ↑ a b c d e Raimund Wallner In: MarineForum. No. 4, 2006, pp. 10-18, ISSN  0172-8547 .
  9. ^ A b c Henrik Goesmann: New submarine technology.  ( Page no longer available , search in web archives ) (PDF) In: Strategy and Technology. October 2005, pp. 56-60, ISSN 0038-0989@1@ 2Template: Toter Link / www.soldat-und-technik.de  
  10. ^ Otfried Nassauer, Christopher Steinmetz: Armaments cooperation between Germany and Israel.
  11. ↑ Oliver Puggé: The BWB and the departments in the transformation. (PDF) Brochure from the Federal Office for Defense Technology and Procurement, August 2004
  12. ↑ Navy puts new ships into service. ( Memento of October 22, 2013 in the Internet Archive ) Press release of the Federal Government of April 26, 2006, accessed April 17, 2018
  13. ↑ The Lübeck Waterways and Shipping Authority inaugurates the Earth's magnetic field simulator. (PDF; 57 kB) Press release from the Lübeck Waterways and Shipping Office dated November 7, 2005
  14. ↑ Alexander Anthon: U 32 demonstrates its operational capability. Press release of the German Navy from April 25, 2006
  15. ↑ a b Federal Office for Defense Technology and Procurement:  ( Page no longer available , search in web archives ) Contract signing for two U 212 A submarines. Press release of the German Navy from September 22, 2006@1@ 2Template: Dead Link / www.marine.de
  16. ↑ a b Gordon Repinski, Marcel Rosenbach , Gerald Traufetter: Das Boot . In: Der Spiegel . No. 4 , 2015, p. 40-42 ( online ).
  17. ^ Bettina Berg: Minister de Maizière approves conversion. bmvg.de, October 21, 2011, accessed on October 25, 2011 .
  18. ^ A b Ministry of Defense: Germany chosen as strategic partner for new submarines to Norway. February 3, 2017, Retrieved February 3, 2017 (UK English).
  19. ^ Ag: Norway wants German submarines (addendum: BMVg): eyes straight ahead. Retrieved February 3, 2017 .
  20. ↑ Dieter Stockfisch: Second lot of the U-Boats class 212A - improvements and further developments. (PDF; 400 kB) In: European Security & Technology , February 2010; accessed on April 17, 2018
  21. ^ Italy matches French naval tie-up with German sub partnership. Defense News, July 22, 2019
  22. ↑ ThyssenKrupp Marine Systems selected as supplier. Norway is procuring submarines with Germany. hartpunkt.de, The Monitor for Defense and Security Policy, February 3, 2017, accessed on April 22, 2018 .
  23. ^ Tino Fritsch: German-Norwegian partnership: Kongsberg and thyssenkrupp establish joint venture. thyssenkrupp press release, October 31, 2017, accessed April 16, 2018 .
  24. ↑ a b c Gerd Kebschull: Silent and invisible. In: Die Welt.de. December 17, 2005
  25. ↑ TV show: ARD Planet Wissen - The history of the submarines. Broadcast on September 16, 2009.
  26. ^ A. Binder: Permanent magnet synchronous machines. (PDF) Lecture notes, TU Darmstadt
  27. ↑ Siemens AG: Sinavy CIS Permasyn. (PDF)
  28. ↑ dagbladet.no
  29. ↑ Alexander Kovacev: Testing of the IDAS guided missile. Press release of the German Navy from November 15, 2006
  30. ↑ Lutz Panknier: U 212A. Role and perspective in the range of tasks of the Bundeswehr.  ( Page no longer available , search in web archives ) (PDF) In: Strategy and Technology. March 2006, pp. 58-63, ISSN 0038-0989@1@ 2Template: Toter Link / www.soldat-und-technik.de  
  31. ↑ Frank Behling: Bottleneck in German submarines. In: kn-online. October 18, 2017. Retrieved October 22, 2017 .
  32. ↑ Konstantin von Hammerstein: Ghost Fleet . In: Der Spiegel . No. 15 , 2018, p. 38-40 ( online ).
  33. ^ Yannick Kitzinger: U-Boats under new leadership . In: Eckernförder Zeitung . July 3, 2018, p. 9 .
  34. ↑ U 35. U-boat squadron gets reinforcements. Retrieved March 23, 2015 .
  35. ↑ Achim Winkler: "U 36" handed over to his element. bmvg.de, February 13, 2013, accessed on February 13, 2013 .
  36. ↑ Ministry: Navy will receive two more submarines by 2030. October 10, 2016, accessed October 10, 2016 .
  37. ↑ German Navy puts submarine "U36" into service. October 5, 2016, accessed October 5, 2016 .
  38. ^ Italian MoD approves initial funding for evolved Type 212As. Janes, February 9, 2018
  39. ↑ Italian Navy receives final Type 212 submarine from Fincantieri. Retrieved May 11, 2017 .
  40. ^ Italian MoD set to launch submarine, rescue ship, and anti-ship missile upgrade programs, Janes, November 2, 2018
  41. ^ Peter Hauschildt: Germany - Class 216: Submarines for worldwide use. In: globaldefence.net. February 14, 2012, accessed April 22, 2018 .
  42. ↑ Singapore further details of Invincible-class submarines, Janes, February 19, 2019
  43. ↑ Dieter Stockfisch: Euronaval 2012. (PDF) In: esut.de. European Security & Technology, January 2013, p. 102 ff.
  44. ↑ France and Australia sign submarine deal. December 20, 2016, accessed February 5, 2017 .
  45. ↑ Singapore orders from ThyssenKrupp . ntv.de; Retrieved December 9, 2013.
  46. ↑ ThyssenKrupp Marine Systems receives a major submarine order from Singapore. ThyssenKrupp press release; Retrieved December 9, 2013.
  47. ↑ ndr.de Singapore is buying submarines from Kiel again. Retrieved December 9, 2013.
  48. ↑ Record submarine christened in Kiel, NDR, February 19, 2019
  49. ↑ Germany's TKMS holds launch ceremony for Singapore's first Type 218SG submarine, Janes, February 19, 2019
This version was added to the list of articles worth reading on January 1, 2007 .