Anonymous on August 6, 2021 kindly provided the following information :
This is a latest information on South Korea’s 3000 ton-class (aka KSS-3 or Dosan Ahn Changho-class) submarines [1]. Its air independent propulsion (AIP) consists of 4 x PH1 PEM Fuel Cells each generating 150kW. This AIP is produced by South Korea's Bumhan Industries [2]based on GS Caltex’s fuel cell technology. The AIP uses single-stage or multi-stage fuel cell stack technology [3].
How the key fuel cell hydrogen supply and storage system technologies work is not clear. Siemens provides hydrogen storage using a metal hydride cylinder system to TKMS designed submarines. But Siemens does not provide it for KSS-3s. So another system (such as pure hydrogen cylinders) may be used fro the KSS-3s.
The submarine is presumably powered by 4 x MTU16V-396 (3.96 MW) diesels, with the permission of MTU and TKMS. But South Korea's DSME, which builds the KSS-3s, does not provide details of TKMS licencing (eg. for the diesel mounting sysytem) or that of German component makers (eg. diesels designed by MTU)?[4]
First DSME KSS-3 named Dosan Ahn Changho (SS 083)
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[1] Excellentwebsite from South Korea with many KSS-3 "Dosan Ahn Changho" details. Also see Wikipedia.
[2] Highly detailed South Korean Bumhan Industries media release.
[3]Patent of Bumhan.
[4] MTU submarine diesels are protected by many of patents. TKMS has a patent for the diesel mounting system.
Pete Comment
As South Korea’s DSME exported 3 whole TKMS designed Type 209 variants (aka Improved Jang Bogos) to Indonesia DSME must have a legal licence from TKMS to export TKMS designed submarines. This is probably only to Indo-Pacific regional countries. The Improved Jang Bogos DSME exported to Indonesia also have 4 x MTU 12V 493 diesels and 1 x Siemens electric motor. So DSME must also have, at least, a regional licence from MTU and Siemens to export.
Also Indonesia may have separate MTU and Siemens licences for its DSME built submarines. See "mtu SUBMARINE ENGINES" brochure which says “Globally, over 20 naval forces have equipped their submarine fleets with mtu diesel engines.” At the website mtu "GLOBAL LOCATIONS" clickon "North East Asia without China" - see MTU (which is part of Rolls-Royce) has an office at "Busan, South Korea". Busan is a South Korean Naval Base port city. For separate Indonesian licencing of mtu diesels for submarine click on "South East Asia with India" which reveals MTU Indonesia [at] Balikpapan on Kalimantan (was Borneo). Balikpapan hosts an Indonesian naval base.
TKMS is competing to export submarines to India in the Projecy-75I (for India) competition. DSME is also a competitor and a certain level of DSME's offer (which is reportedly a KSS-3) was invented by TKMS. So DSME may have bought regional licence approvals from TKMS to export to India.
By Anonymous and Pete