May 19, 2017

Singapore’s submarines, particularly 218SG Propulsion


Originally TKMS broke a complacent Kockums' monopoly when Singapore ordered TKMS subs in November 2013This was the first batch of 2 x TKMS Type 218SGs (covered by Submarine Matters at the time). 

By September 3, 2015 enough details emerged on the 218s to write quite a long Submarine Matters’ description.

On May 15-16, 2017 Singapore announced the order of 2 more 218s.

The first two 218SGs (in 2021-2022) will replace the two ex-Swedish subs, renamed RSS Chieftain and RSS Conqueror of the Singaporean Challenger class

The second batch of the 218s (in the mid 2020s) will replace two more modern ex-Swedish subs, renamed RSS Archer and RSS Swordsman, of the Archer class.


Singapore has long maintained several advanced submarines to:

-  work with nearby sensor arrays, surface and aircraft and allies to monitor activities of non-state 
   actors (Islamic terrorists, drug and arms smugglers, pirates etc)
-  monitor Chinese SSNs and SSKs transiting the Malacca Strait
-  protect the small city-state of Singapore against much larger neighbours (Malaysia, Indonesia and
   Vietnam) that also own submarines, and
-  for intelligence gathering (electronic and special forces, etc)


Its interesting to guess what propulsion types the first and second batches of 218s will have.


All four 218s may feature more efficient, more available, Reformer fuel cell (FC)/Air Independent Propulsion (AIP). On this type of AIP see page 42Spain’s Sener company may be still helping TKMS develop this AIP. Sener indicates

“To solve this problem, and given that the general market trend is to build ever larger submarines, SENER has partnered with ThyssenKrupp Marine Systems (TKMS), the European leader in submarine construction, to develop an AIP based on the methanol reforming process, which allows the hydrogen needed to feed the fuel cell to be produced on board.” 

Or the first two 218s may begin with existing HDW PEM fuel cell AIP and be later retrofitted with Reformer FC/AIP. 

German battery companies may be working with US EnerSys and/or General Atomics to develop more efficient and advanced Lithium-ion Batteries (LIBs) for the 218s. EnerSys supplies batteries for diesel-electric (batteries are essentiall day-to-day) and nuclear subs (for backup). General Atomics  may be supplying the LIBs used by US Special Forces mini-subs.


The first two 218s may be fitted with MTU 16V396 SE (3.96 MW) diesels [1]. This would make it easier to retrofit more modern MTU 12V4000s. MTU 12V4000s may be fitted to the the second two 218s.

[1] In the spirit of some European companies sharing sensitive military equipment. "The beating hearts of [China's Yuan and Song submarines] are state-of-the-art diesel engines designed by MTU Friedrichshafen GmbH of Friedrichshafen, Germany." 

A Type 218SG model first displayed at IMDEX ASIA in Singapore, May 19-21 2015.

The 218's X-plane tale (Courtesy Coffee and Bullets)



MHalblaub said...

Dear Pete,
I guess the part of Sener is to get TKMS in Spanish submarine building process.
TKMS is developing a methanol reformer for quite a long time since 1995. Spain did set up its requirements for S80 in 2001.
Also did Germany already a lot of scientific work in that field and as you can see here the first steps to integrate a reformer into a submarine were done in 2010:

Therefor a reliable reformer should be available at time to integrate into Type 218. I doubt it would be very easy to exchange all the Hydrogen storage devices with tanks for fluid methanol.

According to the diesel engines I would guess the MTU 4000 should be ready for submarine use then. The Armidale-class patrol boat is already running on MTU 4000 diesel. In 2014 the submarine version was already tested:

Batteries are a secondary issue for a fuel cell submarine without the requirement of fast transit speeds.


Peter Coates said...

Hi MHalblaub [your 20/5/17 7:07 PM]

Very interesting.

I'll turn the information in your comment into an article for Tuesday 23 May, about 8am Berlin time.

If you have more information please send it before that date/time.



Anonymous said...

Any thoughts on this?

Would love to see a blog post about it. Seems pretty cool, I would guess it is aimed mainly at Poland.

How would the submarine change from such an insert? Would it be much different from the 10-12m AIP-plug that was inserted into the Archer class?

Since they have made it public Im assuming that they have gotten the permission from US and the blueprints for it.

As I said, would love to see a post about it.

Anonymous said...

Hi Pete

What is difference between 214 and 218 except X-rudder and hull length? Singapore should have requsted bigger beam like Israel and Holland.

By the way, President Trump should withdraw US military from NATO. Some of NATO core members, who donot pay well NATO expenditure, export weapons or related equipments to China at the expense of peace in Pacific area.


Anonymous said...

TLAM like plug will likely become a standard feature of SSK going forward. Time for Australia to update their specs. My guess, it will not be long before Russia will be offering a UKSK plug on its Kilo so you can put in Klub for ground attack and Brahmos for antiship.

France's prosecutor office is investigating possible corruption and briberies on the sale of SSKs to Brazil in 2009. There were similar suspicions with Malaysia as well.

Peter Coates said...

Hi KQN and Anonymous [at 22/5/17 12:21 AM]

I'll do an A26 TLAM plug post on Thursday 25 May if there is no time critical matter that bumps it to a latter date.

A thought - TLAMs can be fired through existing horizontal torpedo tubes. Why have dedicated vertical plugs for TLAMs?



Anonymous said...

Yes Pete. I don't get the hype about vertical launchers. Makes your SSK rather big and you will never have the number of missiles to do as much damage as the US Navy did at that Syrian airport (~50 missiles).
So it may only be to support special forces operations at relatively little defended positions.

koppen89 said...

I would guess capacity is the main factor, as it won't take away anything from the torpedo capacity. Also takes a rather long time to reload the torpedo tubes. Blowing out 18 missiles vertically in a few minutes is probably preferable. If you are gonna use cruise missiles on an SSK you might as well.

Gonna be interesting to follow this one.

Anonymous said...

The main advantage with verical launchers is the ability to salvo that you don't get with firing through torpedo tubes. Most SSK's have 4 - 8 tubes & as koppen89 indicated they are slow to reload. Also the biggest advantage a SSK has is its stealth & it has just blowen its cover by firing. If you want to land a dozen missiles on a target, especially if its mobile (or parts of it are such as planes on an airbase), then you want to fire them quickly. Also long range land attack missiles are of no value against attacking warships or submarines so every land attack missile you load in a torpedo tube is one less torpedo or anti-ship missile you can fire in a hurry.

The main disadvantage is they can't be reloaded at sea. This also means that whatever you have loaded is what you are stuck with unless you return to a major naval base. So there is little point in having the vertical launchers (they are not free) if you can't afford to fill them & TLAM (or SCALPN) are not cheap.