Characteristics of the German-Norwegian Type 212CD Submarine

The above Youtube is from Poland's Balt Military Expo 2018. At 1 minute in the Type 212CD is introduced by a senior ThyssenKrupp executive. (Youtube courtesy Xavier Vavasseur, Chief Editor, Navy Recognition). 
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Following Anonymous’s December 20, 2017 advice thanks Anonymous for providing comments of February 12, 2019 further translated below by Pete.

According to recent information [1], [2] and [3] the TKMS Type 212CD (for Common Design) will be equipped with Lithium-ion Batteries (LIBs), two MTU diesels, a new generation PMSM (Siemens Permasyn motor) and new generation fuel cell (FC) AIP (utilising Siemens' metal hydride).

In the new generation FC, the metal hydride as a hydrogen source makes it safer than a more flammable hydrogen cylinder. A downside of metal hydride is its heavy weight, so an overall increase in submarine buoyancy is needed.

TKMS and Spain’s SENER are developing a more advanced methanol reforming FC technology. A weak point of methanol reforming FC is its limited diving depth due to the physical need to expel carbon dioxide against countervailing water pressure. Such a limitation has already been identified in Kockums Stirling AIP technology.

Like the preceding Type 212A, the 212CD’s hull is made of non-magnetic steel.

Judging by the ease of design, efficiency of production and common use of parts, the 212CD is presumably a larger version of the existing 212A owing to the extra diesel and larger crew quarters on the 212CD . This is in the same way that SAAB A26 Pelagic series can be stretched (with a hull plug addition) into Oceanic and Oceanic ER versions.

The hull diameter/beam of the 212CD may be the same (at 6.8m) as the 212A. This is because any change to the diameter would require a total rearrangement of 212 structure and parts. L (length) to D(diameter) ratio for the 212A is 8.23 (L=56m, D=6.8m) within the maximum L/D ration of a modern submarine of 10.5.

If L/D ration for the 212CD is 10.5, then this may point to a theoretical Length of 71.5m for the 212CD. Furthermore this may point to a 212CD displacement increase of around 20% (maybe 2,200 long tons submerged) compared to the 212A’s 1,830 long tons submerged.

Noting this caution, the 212CD’s LIBs will very likely be SAFT made lithium iron phosphate (LFP) which is stable at low temperature making the 212CD suited to operation in below zero Celsius Baltic Sea or Arctic Ocean conditions.

A simple exchange of the 212A’s Lead-acid Batteries (LABs) for LIBs is not feasible because LIBs operate at significantly higher voltages than LABs. This means many of the components and electrical junctions for the 212CD will need to be new.

Use of the 212CD for the Netherland’s Walrus replacement is difficult, because the likely Dutch diameter/beam requirement is 8.4m, which is considerably larger than the 212CD’s possible 6.8m diameter. This means if TKMS does not offer a large Type 216 (once offered to Australia) TKMS may lose a Walrus replacement decision in the early 2020s. Instead a large SAAB A26  (and see) or a small Naval Group Shortfin may win the Walrus replacement competition.

[1] https://www.tu.no/artikler/norges-nye-ubater-kan-fa-nyutviklede-litiumion-batterier-fra-thyssenkrupp/449338 [right-click mouse translate from Norwegian.] Norway's new submarines can receive newly developed lithium ion batteries offered by ThyssenKrupp.

[2] https://www.tu.no/artikler/norges-nye-ubat-kan-bli-forst-med-litiumionbatterier-eller-sist-med-blybatterier/427238 [in Norwegian] Norway's new submarine can be first with lithium-ion batteries - or last with lead-acid batteries.

[3] https://www.defence24.com/pdf/?article=orka--the-german-way-will-the-polish-navy-submarines-be-built-in-szczecin [PDF about 5MB, in English] “ORKA – The German Way: Will The Polish Navy Submarines Be Built In Szczecin?” page 5. There is a scarcity of information available on the 212CD submarines. Even the dimensions remain confidential. The vessel is going to be derived from the 212A submarines. As the representatives of the shipyard admit, the [212CD] will be fitted with two MTU diesels, while the older [212As] use a single [diesel]. Also see more on Poland’s future submarine competition.

COMMENT

As will be seen next week there is uncertainty over the Type 212CD’s 2 x MTU diesel arrangement, which may make it more suitable as a Walrus replacement than originally thought.

Mostly Anonymous and a bit Pete