Flotsam – December

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Search for the lost ARA San Juan continues

The search for survivors of the San Juan crew was ended on 30 November, but the search for the submarine continued with international support. In this search also one followed many hints, which turned out as wrong tracks later. The Argentinean Navy also had to revise some of its statements, which is why the chronology of events begun in Flotsam Edition November is to be continued.

Friday, 1 December

The relatives of the crew of the San Juan met with the Argentinean Defence Minister, while the crew had not yet been officially declared dead. At the meeting, which took place in a tense atmosphere, the relatives demanded clarity about the fate of the crew.

Saturday, 2 December

The Argentinean Navy expressed understanding for the situation of the relatives. Four sonar contacts at a depth of approx. 500 m were examined in detail. None of these contacts turned out to be the remains of the San Juan.

Monday, 4 December

The Argentinean Defence Minister officially confirmed on television for the first time that the 44 crew members of the San Juan were dead and admitted that one might never know what exactly happened.

Tuesday, 5 December

The Argentinean Navy confirmed that on 15 November, San Juan established 8 data links via the Iridium satellite communications system, as evidenced by the records of the South American telecommunications provider Tesacom. So the satellite signals, which were mentioned on 19 and 20 November, came from the San Juan after all. In addition to conventional terrestrial radio equipment, the San Juan was also likely to have satellite communication equipment. It is not a particular technical challenge to install them in submarine masts, so San Juan likely did not even have to surface for satellite communications.

A fixed Iridium ship antenna on a passenger ship. Photo: Lilpop,Rau&Loewenstein, CC BY-SA 3.0

Especially in terms of data throughput rate, satellite communication is superior to any kind of terrestrial radio communication. Iridium’s satellite coverage is guaranteed at all points on the earth’s surface, including the polar caps and also in the most severe of seas. Since the Argentinean navy could hardly launch its own communication satellites into space, it must inevitably use the services of a civil telecommunications provider to communicate with its units at sea by satellite.

The San Juan‘s latest message, presented by the Argentinean Navy on 27 November, is quite obviously a traditional radio message that is only a few hundred bytes in size as digital data. But Tesacom charged a total of just over 50 minutes of data connections on November 15. The upload rate of the Iridium data connection is 512 kBit/s. So if San Juan has used only a few minutes of these connections to transfer data, the volume of this data is likely to have been a few dozen MB. However, the Argentinian Navy did not provide any further information on the content of this data.

Wednesday, 6 December

The Argentinean navy claimed that the satellite connections were not emergency calls, but attempts to access the Internet.

Thursday, 7 December – Fading media interest

An Argentinean spokesman for the Navy announced that Iridium had not stored the data from the San Juan satellite links and therefore had no knowledge of their possible content. Against the backdrop of issuing an arrest warrant against the Argentinean ex-president Fernandez de Kirchner, only 3 journalists showed up for this press conference, which was not broadcast live on television as it was in the past.

Friday, December 8 – A cigarette on a football field

After the search area had already been searched twice without success, the spokesman of the Argentinean Navy affirmed that the search for the submarine would continue until all resources were exhausted. He added that the search for the San Juan is like finding a cigarette on a football field.

Sunday, September 10

After having analysed the first important documents, the Argentine Federal Judge Marta Yunez could not yet say whether someone could be held responsible. First relatives of the San Juan crew turned to politics for support.

Tuesday, 12 September

In order to ensure the transparency of the investigations, two naval officers were suspended from service on the orders of the Argentinean government as a precautionary measure, and another one applied to retire. The Argentinean Navy cancelled two scheduled press conferences on short notice. The last photo of the crew of the San Juan before their loss was published.

Wednesday, 13 September

A group of the crew´s relatives approached the Argentinean Congress with a request for the establishment of an independent commission of inquiry. They were received by members of the government and the opposition. Meanwhile, the Argentinean Navy confirmed that there was no date for the end of international cooperation in the search for the San Juan.

The American research vessel Atlantis with a mini-submarine of the Woods Hole Oceanographic Institution. Photo: US National Oceanographic and Atmospheric Administration (NOAA)

Thursday, 14 December

The Argentinean Navy confirmed that 3 clues that were investigated by the American research vessel Atlantis of the research organization Woods Hole Oceanographic Institution had no connection to the San Juan. Crew members gathered at the Mar del Plata submarine base assured that they would not leave until the lost submarine was found.

The Argentinian submarine ARA San Juan, missing since mid-November, is an export submarine from Germany of the type TR 1700, which is why background information on this extremely innovative submarine of Thyssen Nordseewerke (TNSW) in Emden is to be provided below.

The two TR-1700 boats ARA Santa Cruz and ARA San Juan at the submarine base Mar del Plata in 2007. Photo: Martín Otero, CC BY 2.5

Type TR 1700
ARA Santa Cruz, ARA San Juan = 2 submarines

Submarine type developed and built by Thyssen Nordseewerke in Emden for export with high underwater speed, diving depth and range.


ARA Santa Cruz, ARA San Juan


Thyssen Nordseewerke in Emden


10/12/1984 and 11/19/1985


2,140 t, 2,336 t submerged


67.3 m


8.36 m


7.34 m

Engine Power

6.600 kW (electric engine)


15 kn / 25 kn submerged



Diving Depth

250 m


6 bow torpedo tubes



The submarine type TR 1400 was developed from 1974 onwards by the TNSW submarine design bureau, which was set up in the early 1970s. After a smaller submarine type of approx. 500 t, developed here on the basis of designs by Ingenieurkontor Lübeck (IKL), had not found a buyer and after Germany had been permitted by the Western European Union, to build an unlimited number of submarines of a size of up to 1,800 tons, they started to develop completely new submarine types for export based on their own ideas, which were given the designation TR 1400 and TR 1700. As a result, the TNSW submarine design office became the first domestic German competitor for the IKL, which otherwise dominated the market for submarine development in Germany. IKL was based at the Howaldtswerke-Deutsche Werft (HDW) in Kiel, Germany, until it was taken over completely by HDW in 1994.

Since many innovative approaches had been pursued in the development of the types TR 1400 and TR1700, the designs differed considerably from those of the IKL, such as the submarine type 209, which had already been exported in the 1970s and which, with more than 60 units built to date, was to become the best-selling type of submarine worldwide.

The submarine type TR 1700 is a diesel-electric submarine with a drive shaft driven by a powerful Siemens main electric enginge. Power is generated by four diesel generators from MTU Friedrichshafen, which is stored in 960 battery cells. The armament consisted of 6 torpedo tubes, two less than in comparable IKL designs, with a torpedo magazine for 16 reserve torpedoes. The torpedoes could be reloaded in less than 15 minutes. Wired-guided torpedoes of the German type SST-4, the export version of the German Navy’s long-standing standard torpedo against surface targets and modifications of the American Mk 37 torpedo for combating submarines are carried. Instead of torpedoes, the submarine can also be equipped with mines. The access to the tower above the operation centre (OPZ) is designed as a diver’s airlock and enables the deployment of special forces.

The TR-1700 boats were equipped ex works with the most modern sonar systems of the German company Atlas at that time. The masts, such as the snorkel, also corresponded to the state of the art at that time. The size of the submarines made it possible to carry large quantities of fuel and provisions, and to divide the boat’s interior into two decks in the front half of the pressure hull. This created more space and comfort for the crew to allow longer ventures of up to 70 days. This interior design influenced the later development of the submarine type 212 as well as the export types 214 and Dolphyn. Another important advantage of the division into two decks is that there is no transit traffic through the OPZ.

There are no details on the range of the submarine type TR 1700. When the ARA Santa Cruz docked at her future base Mar del Plata after its transfer from Germany to Argentina in 1985, the Argentinean Navy reported that it still had sufficient fuel reserves to return to Europe. With an underwater speed of 25 knots, the TR 1700 is one of the fastest conventional submarines of all times and has already attracted international attention during its tests in Germany due to its outstanding performance. It is also relatively easy to control and relatively inexpensive in purchase and maintenance.

At the beginning of the 1970s, the Argentinean Navy, like some other navies, was looking for replacements for their now hopelessly outdated submarine stocks, which were mainly taken over from the USA. After the Argentinean government under Perón in his second term of office had sought offers for submarines worldwide, only HDW with its type 1500 and TNSW with its submarine types TR 1400 and 1700 remained in the shortlist. TNSW was finally awarded the contract and in early 1978 a contract for the construction of six submarines was signed. The type ship was to be built in Emden and the remaining five boats were to be built at an Argentinean shipyard still to be set up with the help of TNSW. Two of these submarines were to be of the smaller type TR 1400.

In 1981 the Treaty was then amended. All six boats should now be of the larger type TR 1700. Two vessels were to be built at TNSW and the remaining four in Argentina. The construction of the submarines should be carried out in the well-proven construction in sections. Construction of the sections for the first submarine started on 10 December 1978. The assembling of the sections began on 26 December 1981 in TNSW’s large assembly hall. The 90% completed vessel was pulled out of the assembly hall into a floating dock on 20 September 1982 and then completed and equipped. During the subsequent tests, the boat showed excellent performance, but the petty acceptance practice of the Argentinean Navy delayed the payment of approximately 330 million DM for the submarine. On 12. October 1984 the first Argentinean submarine, the ARA Santa Cruz, was ceremonially commissioned in Emden. In mid-November, the Santa Cruz departed for her transfer trip to Argentina. On 14. December 1984 she was received with military honours at her future base Mar del Plata. The submarine travelled the approx. 6,500 nautical miles submerged with an average speed of just over 10 knots. The second Argentinian submarine, the ARA San Juan followed one year later on 19 November 1985 with an average speed of 11 knots and a 10% reduction in fuel consumption.

While the two submarines destined for Argentina were still under construction in Emden, a state-owned submarine yard was set up in Buenos Aires with the help of TNSW under the name Astillero Ministro Manuel Domecq García for the construction of the 4 remaining TR 1700 boats, the construction of which began immediately. To date, none of these 4 boats have been completed. One submarine, the Santa Fe, is about 70% finished and could still be completed according to an Argentinean feasibility study. Another one, the Santiago del Estero is 30% ready. The construction of the two remaining boats was abandoned at an early stage and the parts delivered from Germany were used as spare parts for the two active submarines.

The Santa Cruz and the San Juan were overhauled after a period of service in Argentina of 20 and 25 years respectively at the Argentinian submarine yard. For this purpose, the submarines were lifted out of the water by means of a syncrolift, a ship lifting system for larger ships and initially freed from incrustations. The paint was removed comparatively gently by means of an ultra-high pressure water jet. The four MTU diesel generators were replaced by four from the 1982 TNSW delivery for the Argentinian submarine construction project, which eventually did not take place. Like all 960 battery cells, the electric motor was also removed from the pressure hull and completely remanufactured. All technical systems were disassembled and completely overhauled. After the re-installation of all removed components, the two halves of the pressure hull had to be aligned exactly to each other and then welded by hand, as is common practice with TNSW. The welder cannot set down but has to weld in one pass. This work took 12 hours for the ARA San Juan. The metal was heated to the temperature required for welding by means of heating devices. The welding process itself took place under a special tent in order to avoid even the slightest draught of air that could cool down the metal, whereby the welders had to use breathing apparatus.

Afterwards, the weld seams were sanded and subjected to a meticulous examination by X-ray and ultrasound. The 10 m long propeller shaft, which was reworked in a special lathe, was fitted again exactly. Finally, the boats were painted with their traditional black paint and could be returned to their element.

These major overhauls took place for ARA Santa Cruz between September 1999 and 2001, for ARA San Juan between 2008 and 2013 due to financing difficulties. According to the Argentine Ministry of Defence, approximately 500,000 man-hours and 240 million pesos (approx. 22 million euros) were spent on the overhaul of the San Juan.