February 28, 2017

German, French, Spanish, Reformer Fuel Cell AIP, Japanese LIBs

Advanced French AIP proposal. “Simplified” Layout of Diesel Fuel Processing Equipment (Diesel Fuel Autothempermal Reformer – SOFC). Layout and description courtesy Bakst Engineering.


The following is the section on AIP within an excellent article The Driving Factor In The SEA 1000 Choice The Submarine Propulsion Chain by submarine expert Rex Patrick, from Sydney, Australia. This was on pages 40 to 44 of the October 2015 issue (Volume 41, Number 8) of the Asia-Pacific Defence Reporter (APDR). APDR is an excellent magazine provided by subscription.

It was written before the Australian Government’s 26 April 2016 SEA 1000 decision in favour of the French DCNS Shortfin – but the article's comments on AIP still appear accurate.

Significantly the article is also published on the Siemens' website here

Pete has bolded for emphasis some words in the following AIP section and also added footnotes [1] and [2]. The footnotes indicate that the AIP section is still current and accurate. Japan and Lithium-ion Batteries (LIBs) are also discussed towards the end.



The primary purpose of an AIP system is to convert stored reactant energy into electrical energy for the submarine’s main battery and to do so independently of the surface atmosphere. It provides little benefit during transits but is invaluable when operating slowly within an operational area.

TKMS will almost certainly offer Australia a reformer/ FC solution. Being a large submarine, it will demand two reformers and four 120 kW FCs.

The first element of TKMS’ AIP solution is a Methanol reformer that extracts hydrogen from methanol and feeds it directly into the FC. Methanol is selected because of its worldwide availability, high hydrogen content, low reforming temperature (250°C), reformation ease and high reforming efficiency (80 to 90%). LOX is also used in the reforming process. Sub-system waste is pressurised CO2 which can be discharged to sea down to full diving depth. The reformer is packaged in an enclosure with its own special ventilation system for cooling.

Each reformer is capable of producing enough hydrogen to supply two fully loaded 120 kW cells. It removes the need to store hydrogen on board, which is problematic from a supply availability and refuelling complexity perspective, and is also difficult on 2000+ tonne submarines because of the weight of the hydrogen’s metal hydride storage bottles.

The reformer has a two to three hour start-up time. Operationally, the idea is to start it up in the patrol area in block periods where AIP can be exploited, potentially for weeks on end, dependant on the amount of reactant stored on board.

The reformer has been in development since 1995 and a test site has been in operation for a decade, with FCs connected to it since 2010. A reformer suitably packaged for installation on board submarines is currently undergoing set-to-work in Kiel. Whilst the reformer has not been fielded on a submarine yet it is at the test bed state and therefore it attracts a low SEA 1000 project risk label.

Moving to the FC, TKMS will offer the second generation Siemens 120 kW Polymer Electrolytic Membrane (PEM) FC. The PEM FC works by feeding standard industry-grade LOX and high purity hydrogen into the cell which generate electricity in response. It does this silently and at a low temperature (80°C). It is different to a battery in that it stores no charge; it simply generates electrical energy so long as the reactants are fed into the cell. The cell is extremely (fuel burn) efficient at between 50 and 70%. Its ‘waste’ outputs are potable water, which is fed into holding tanks, and (1%) oxygen, which is fed into the submarine’s atmosphere to assist in maintaining breathable air during prolonged AIP dived periods.

The FC has been under development by Siemens since the early eighties. It was first trialled on a German Type 205 test submarine in 1988 and then contracted for supply into the German and Italian Type 212 program. The first production FC went to sea in 2002 and it is now a very mature system at sea on 24 submarines, meaning it is a minimal project risk component of the German SEA 1000 solution.

The reformer/FC system meets all of the fundamental requirements of an AIP system; high efficiency, silent, low magnetic signature, light and compact, generates no pollution or heat, reliable, relatively easy to maintain and requiring no additional operating personnel.

Public domain information shows DCNS have abandoned their MESMA AIP solution on the Pakistani Agosta 90s and will use a diesel reformer/FC solution on the Shortfin Barracuda. [No supporting detail seen to date.]

It is interesting that the German Defence Department funded TKMS starting in 2007 to conduct a methanol vs diesel reformer comparison, because the diesel reformer approach would negate the need for storage of an additional fuel, methanol, on board the submarine. TKMS built a small 10 kW diesel reformer to support the study. The study conclusions were instructive. The diesel reformer was less efficient because diesel has a hydrogen to carbon ratio of only two to one, whereas methanol has a hydrogen to carbon ratio of four to one. The diesel reformer also needs to run at around 850 degrees which implies heat inefficiency as compared methanol. The higher temperature also means a longer start-up time than the methanol reformer. Finally, unless the diesel carried by the submarine is sulphur free, and standard diesel is not, the required sulphur purifier at the reformer output would likely take up considerable space (as big as the reformer itself). The idea was abandoned.

As to the French FC, it appears as though two options are on the table; a PEM or Solid Oxide FC (‘SOFC’) type. If a SOFC is chosen, noting they offer good energy conversion efficiency, long life and operating cost advantages, other drawbacks need to be addressed. Most of these drawbacks relate to the high 600 to 1000°C operating temperature which brings hot exhaust issues and brittleness related shock resistance problems.

Novelty, complexity and uncertainty put this solution’s inclusion in the French package as high risk. Even if the technical challenges of the diesel reformer and FC are solved, the enemy of the DCNS development will be schedule. DCNS are believed to have started their reformer/FC work back around 2006/7 and announced it as a future solution in 2008 as part of their SMX 24 concept design. [1] It is instructive that the Germans have developed and perfected their reformer/FC solution over four decades. It is also worthy of note that the Spanish have had issues with their S-80 submarine ethanol reformer/FC solution and have announced that the first S-80 will now be fitted-for-but-not-with AIP.[2]

The Japanese will not offer up an AIP solution, rather fill any potential AIP space with additional Li-Ion batteries. It is believed this decision stems from their experience with the inefficiency of the Swedish origin Stirling AIP solution. All things considered with respect to reported Stirling engine maintenance overheads and the lack of differential between the Stirling energy density and the Li-Ion energy density, the decision is likely valid.

However, the energy-density differential between the DCNS and TKMS FC and the Japanese Li-Ion’s is large, giving the Japanese solution a poorer indiscretion ratio than the Europeans’ FC approach. It is known that the Japanese originally approached TKMS about adopting their FC AIP solution, but the adoption of the German technology was problematic for two reasons; firstly, the reformer necessary for the larger Soryu submarine was not mature at the time and TKMS/Siemens were not inclined to transfer knowledge of what they considered to be the ‘crown jewels’ of their submarine program. Whilst Li-Ion may have advantages in transit situations, which is why the French and Germans have Li-Ion as part of their solutions, the FC provides the advantage where it really counts; in the operational area. Whilst an all Li-Ion Japanese solution may have advantages with respect to transiting, it means little if the boat is then sunk upon arrival in its assigned patrol area.


[1] The possibility of French DCNS progress is recorded in a DCNS article of 13 October 2016 for Euronaval 2016: “FC2G AIP – Fuel Cell: Second-generation Air-Independent Propulsion. DCNS has developed the 2nd generation AIP system using fuel-cell technology. FC2G AIP provides the best possible dive autonomy in total safety and easy support.”

[2] Spain's problems are covered in IHS Jane’s article of 24 January 2017, which indicates: “Spain's first S 80-class submarine will not be fitted out with [AIP] as development of the system will not be ready in time, according to the admiral in charge of Maritime Action (Almart)...He also said he was not sure which of the four new boats would be the first to be fitted with the AIP system.”

February 27, 2017

Midlife Overhaul for Dutch Submarines - Operational to 2025

A Walrus class submarine moving quickly. At 2,450 short tons (surfaced), 2,800 tons (submerged), with a crew of 49 to 60 - in Europe the Walrus is a uniquely large SSK class.

A 25 February 2017 comment from Kevin has prompted me to write two updates on:
-  Dutch Walrus class submarine overhauls (below), and
-  later this week Dutch submarine replacement issues and requirements.

The issue of overhaul or replacement of the Netherlands 4 Walrus class submarines, launched between 1985 and 1992, has been long discussed in Dutch naval and political circles. Originally the Walrus class were designed to operate for just 25 years (until around 2015). 

But the Walruses have operated mostly in shallow coastal waters (shallow immersion cycles). Hence the physical demands (contraction and expansion of the steel hulls causing metal fatigue) have been less than originally expected. Possibly the Walruses have been mainly used for signals monitoring as they are too slow for hunter-killer duties, chasing SSNs, SSGNs and SSBNs. The Walrus class  operating life has therefore been increased to 35 years, allowing the subs to remain in use until at least 2025.

The Walrus mid-life overhaul is known as the Capability Upkeep Program (CUP) [in Dutch 1]. The CUP overhaul program began in mid 2014 starting with His Netherland Majesty's Ship (HNLMS) Sealion [1]. Overhauls will continue until 2020. The CUP has also been called the Life Extension Program (LEP).

The overhaul includes:

-  modernising sensors, such as:
   = new sonars allowing the sub to draw closer to the coast (aka “near shore”) to gather intelligence.
      The suite includes a Mine and Obstacle Avoidance Sonar by ELAC Nautik.
   = New optronics masts [1] from L-3 KEO permitting sub to quickly see 360 degrees around itself,
      with less risk of discovery tan a periscope or older optronic. The new optronics suite includes a
      thermal imaging camera [1] providing HD footage both day and night. Optronics allow very sharp
      images to be visible on a screen for most in the sub's command center (not just one viewer's old
      periscope eyeball).

-  upgraded weapons including new software and other equipment for the Mark 48 torpedos, moving
   and them from current mod-4 standard to mod-7 CBASS.

-  command and combat systems and communications,
   = including a super high frequency (SHF) satellite communications system allowing messages to
      the submarine from Dutch naval headquarters or NATO Defense Networks, and
   = improved operating software for most systems (likely much work will be by Lockheed Martin).

-  refurbishing, strengthening and de-rusting the pressure hull

Later this week I’ll comment on the Walrus replacement program (yet to be approved by the Dutch Parliament) and on likely requirements and builders of a Dutch future submarine.

[1] these sites are in Dutch. For a PC mouse - right click mouse - then you will see Translate to English - translation may take 20 seconds. 


February 24, 2017

Philippine Navy - Acquiring New Ships Armed With Missiles and Torpedos

A South Korean HHI HDF-3000 frigate which carries missiles and torpedos, The Philippines is buying two. (Photo courtesy rhk111's Military and Arms Page)

The Philippine Navy is gradually catching up to navies of its neighbours and resource competitors, Malaysia and Indonesia. Greater naval friction between these neighbours is likely as the potential prices of contested undersea oil-gas, and even fish prices and scarcity, rise.

The Philippine Navy’s (PN’s) recent interest in acquiring submarines from Russia (Kilos) or maybe China (S20s or S26s) should not be seen as a passing urge from a mere gun only second hand navy. Any future submarine purchase can be seen in the context of the PN’s new trend of paying serious money for new vessels armed with missiles.

In the last few years the PN has bought:

A.  3 x multi-purpose attack craft (MPAC) Mk. 3s, These patrol boats (coming from Israel around June 2017) are being armed with Spike-ER missiles with a 8 km range. The Spikes have roughly the weight and range of Hellfire missiles.

B.   much more substantially a contract (for a total of US$337 million) was concluded October 24, 2016 for 2 new frigates, which are derivatives of the HDF-3000 design. These are being built by Hyundai Heavy Industries, South Korea and are scheduled for delivery starting 2019. These frigates will carry (see and wiki's right sidebar) SAMs, Harpoon like SSM-700K Haeseong anti-ship missiles and lightweight torpedos.

C.  The PN will also mount Spike-NLOS missiles on its soon to be received AW-159 Wildcat naval helicopters. Also LWTs can be mounted. These helicopters could operate from:
-  the 3 old cutter-frigates
-  the new 11,583 ton, Tarlac class landing platform docks (LPDs) - see the photo below, or
-  air bases in critical places like Palawan Island which borders the highly contested Spratly Islands in
   the South China Sea.

The Philippine Navy's new 11,583 ton Tarlac class LPDs can carry helicopters armed with missiles and LWTs. (Photo courtesy Miguel de Guzman via philstar GLOBAL).  


February 22, 2017

China - foreign Submarines & UUVs transiting South China Sea Must Surface

China has, unilaterally claimed "water areas" or "territorial waters" of the South China Sea within its "Nine dash line". (Map courtesy GeoGarage).

In an excellent post that will create headaches for the US, Japanese and Australian navies, Chinese state media, Ecns.cn reports February 15, 2017 China may soon redraft its 1984 Maritime Traffic Safety Law to require:

“Foreign submersibles [ie. submarines and UUVs must] travel on the surface, display national flags and report to Chinese maritime management administrations when they pass China’s water areas”. Such waters are understood to include the South China Sea.

China’s Global Times adds:

“Foreign military ships that are approved to enter China's waters should apply for pilotage. Foreign ships that enter Chinese waters without approval will be fined 300,000-500,000 yuan ([US]$43,706-72,844) and those violating Chinese laws would be expelled, it said.”


China's $73,000 fines may be very reasonable compared to an SSK's or SSN's hourly running costs. Attention Commanders! Take wads of cash or don't leave home without your American Express cards.


February 21, 2017

Performance Table, Lithium-ion Batteries (LIBs) vs Lead-acid Batteries (LABs)

From Anonymous’s comments on February 12, 2017.

Thanks to Anonymous for estimating performance for a submarine that will have new Lithium-ion Batteries (LIBs) no AIP – see Table 1. The first such submarine can be called a “Soryu Mark 2” (see Table 2) and it is designated 27SS which is likely to be launched between October and December 2017.

Anonymous, in Table 1, then makes a traditional Lead-acid Batteries (LABs) only (no AIP) comparison. Japan’s Oyashio class (launched 1996 to 2006) were Japan’s last submarines that were LABs only. The Oyashios preceded the LAB-AIP Soryu Mark 1s (see Table 2).

LIBs/LABs Comparative Table 1.

LIBs only Soryu Mark 2, eg. 27SS
LABs only Oyashio class
Nominal voltage per unit battery-module [1]
Max submerged period at 4 knots [2, 3]
7 to 9 days
3 to 3.5 days
Standard submerged period at 4 knots [4]
6 to 8 days
1 to 1.5 days
Standard period at 18 knots (within a longer mission submerged)
3 to 4 hours
1 hour
Battery Recharge times over 60 day mission
8 to 10 times
40 to 60 times
Battery Recharge periods (surfaced or snorting)
1 to 2 hours
5 to 10 hours

[1] Values are based on various pieces of data for LIBs and LABs. LIB-modules and LAB-modules are connected in parallel and in series, respectively. Example: total voltage of 100 LAB-module (2V) connected in series is 200V = 2V x 100.

[2] Data for LABs is based on various simulations of submarine propulsion.

[3] Data for LIBs is based on comparison with data for LABs.

[4] As complete discharge shortens the life of batteries, I assume 90% of LIBs are discharged and 30% of LABs.

SORYU-Oyashio TABLE 2 (as at February 21, 2017)

Build No
MoF approved amount ¥ Billions & FY
Laid Down
5SS Oyashio
8105 Oyashio
SS-590/ TS3608
¥52.2B FY1993
LABs only
 Jan 1994
Oct 1996
Mar 1998
10 subs
¥52.2B per sub
LABs only
 15SS Feb
Mar 2008
Soryu Mk 1
¥60B FY2004
Mar 2005
Dec 2007
¥58.7B FY2005
Mar 2006
Oct 2008
¥56.2 FY2006
Feb 2007
Oct 2009
¥53B FY2007
Mar 2008
Nov 2010
¥51B FY2008
Mar 2009
Oct 2011
No 21SS built
¥52.8B FY2010
Jan 2011
Oct 2013
¥54.6B FY2011
Feb 2012
Oct 2014
7 Mar 2016
¥54.7B FY2012
Mar 2013
2 Nov 2015
Mar? 2017
¥53.1B FY2013
22 Oct 2013
12 Oct 2016
Mar? 2018
Mar 2019?
27SS First
Soryu Mk 2
LIBs only
Oct-Dec 2017
28SS  Second
Soryu Mark 2
¥63.6B FY2016
LIBs only
Mar 2021?
29SS First of
New Class
¥76B FY2018
LIBs only
Table courtesy of exclusive information provided to Submarine MattersLABs = lead-acid batteries, AIP=air independent propulsion, LIBs=lithium-ion batteries. ¥***B = Billion Yen.

Anonymous and Pete

February 20, 2017

Update on Australia’s SEA1180 Offshore Patrol Vessel (OPV) selection process

Damen's OPV 1800 (Artwork courtesy Damen) is a possibility for Australia's Offshore Patrol Vessel (OPV) competition. Damen also offers the OPV 1800 Sea Axe and the 90m Sigma class. Damen has been shortlisted by Australia  - as have Fassmer and also Lurssen.

Australia’s SEA1180 future Offshore Patrol Vessel (OPV) selection process continues to steam ahead.  It was first announced April 18, 2016A 30 November 2016 Media Release announced a Request for Tender (RFT). Government requirements have been stressing:

-  the three shortlisted designers should devise Australian Industry Capability Plans to team up with
   Australian shipbuilders. Hence the designers are teaming:
   =  the Netherlands' Damen with Civmec
   =  Germany's Fassmer, with Austal, and
   =  Germany's Lurssen (a report February 18, 2017 that Lurssen) may team up with BAE Systems)
-  use of Australian made steel for the hull is important
-  probable displacement may be up to 2,000 tonnes
-  main gun might be 57mm or 76mm.
-  probably no missiles initially, but they could be retrofitted.

The order is for 12 vessels, which will begin with two built in Adelaide from 2018 and ten in   Western Australia from 2020 (this looks messy!).

The OPVs will be used for border protection and other missions of greater range/endurance than the existing, smaller 300 tonne Armidale class patrol boats. The Armidales have suffered from aluminium hull cracking around the engine spaces, partly due to much greater use on illegal immigrant search than anticipated. Hence the new OPVs will have steel hulls.

Glorious photo (courtesy Cotecmar) of a Fassmer 80 OPV . Also a 90m OPV is a possibility.

A Lurssen (or Luerssen) OPV-80. Some are already in our region in the Royal Brunei Navy (Darussalam class). There are also Lurssen OPV 85s and OPV 90s (Photo courtesy pinterest).

The ambitiously tight selection and production deadlines may slip. Production in Adelaide (just two) and Western Australia (ten) also looks uneconomic and problematic.

New OPVs of up to 2,000 tonnes, replacing the old ones of 300 tonnes, will represent a major increase in RAN border protection capabilities. The emphasis will likely be on carrying illegal immigrants, over long ranges and a helicopter for reconnaissance/search and rescue, rather than carrying missiles for combat. 


February 17, 2017

Two types of Japanese Lithium-ion Batteries Being Considered

The video "Why Japan’s Soryu Class Submarines Are So Good "Black Dragon" was published on Oct 3, 2016. See it being launched in video, numbered SS-506. Good on Soryu specifications, modifications for Australia, and strategic value for Japan generally.

Submarine Matters is not the only website writing about Lithium-ion Batties (LIBs) for submarine. Gordon Arthur, Asia-Pacific Editor for Shephard Media, wrote an excellent article in Shephard Media “Japan leads way with Li-ion submarines”.

That article features LIB performance and comparative information provided by Vice Admiral (Retired) Masao Kobayashi (see photo and career biodata). He is the former commander Japanese Navy’s Fleet Submarine Force. He spoke at UDT Asia (Singapore, 18 January 2017). Kobayashi’s information confirms the superiority of LIBs information provided by Anonymous sources to Submarine Matters over the last two years. New information in Gordon Arthur’s article includes:


Japan's first LIB submarine, [that would be the first Soryu Mark 2, 27SS, under construction at MHI see SORYU TABLE] will be commissioned in March 2020 (no lead-acid batteries (LABs) or AIP.


Kobayashi believes that there is no clear single lithium-ion solution as a submarine main battery with future submarines being optimised with different power source. Two LIB types for Japanese submarine use are available:

Lithium nickel cobalt aluminium oxide ( LiNiCoAlO2 ) known as “NCA” manufactured by GS Yuasa. For main traits scroll quarter way down at. The JMSDF will use NCA-type batteries. es. Kobayashi advised for mobile operations, for example, NCA batteries and diesel may be ideal.


Lithium-titanate ( Li4Ti5O12 ) known as “LTO”, from Toshiba. For main traits scroll a third way down at,. Kobayashi believes LTO types were offered to Australia for its SEA 1000, Future Submarine proposal. an ambush submarine would operate better on fuel cells, LTO and diesel.

Kobayashi advised the lowest-cost option may be LTO and diesel.


Japan's LIBs research began in 1962. The first LIB for submarine was ready in 1974 but did not meet requirements (including cost). Fuel cell AIP technology was not yet mature so Japan turned to Stirling AIP. From 1991-97 (Stirling?) AIP was (land tested?) before being installed into a Harushio-class (probably JDS Asashio TSS-3601) submarine in 2000-01 for trials.

“Meanwhile, tests on Li-ion batteries continued to the point that the JMSDF asked for a Li-ion-powered Soryu-class boat [27SS] in its FY2015 budget request.”



March 9, 2016 Inside the Soryu Submarine, Rare Diagram, Photos and Translations http://gentleseas.blogspot.com.au/2016/03/we-all-live-in-black-gray-submarine.html