Japan's Soryu Class Submarine : Collins Replacement Prime Contender

The Collins Class Submarine

 

HMAS Sheean SSG-77 conducting air sea safety assessment with a Seahawk helicopter from HMAS Adelaide off Garden Island, Western Australia. RAN Photo.

 

The Royal Australian Navy (RAN) currently has a fleet of 6 Collins class diesel-electric hunter-killer submarines (SSK) in its arsenal. They were designed in collaboration with Kockums AB of Sweden and largely built in New South Wales, Australia, by the then newly formed Australian Submarine Corporation. They are essentially enlarged versions of the original ( non-AIP )Vastergotland class submarine which then served the Royal Swedish Navy. The RAN classifies them as " Guided Missile Submarine, Diesel-Electric " or SSGs, obviously referring to the Sub Harpoon missile launching capability. The are named after distinguished former members of the Australian Navy. They have pennant numbers from SSG-73 to SSG-78.

At 3100 tonnes surfaced and 3400 tonnes submerged, they were then the world's largest modern non-nuclear submarines. Among the first to be totally designed with computer-aided techniques, they were supposed to be highly automated, have long endurances, quiet, fast and pack a powerful punch. From the RAN webpage "Designed to be as quiet as advanced technology can achieve, Collins Class submarines have been developed from five generations of submarines designed and built by the Swedish Navy."

However, the reality was that the entire Collins project was fraught with problems and delays right from day one and even to this day. The Aussies made the fundamental mistake of taking a completely new submarine design and having it built domestically at a new boat yard with no prior history or experience of submarine construction.

First of class HMAS Collins was laid down in 1990 and commissioned in 1996 while the 6th boat HMAS Rankin was laid down in 1995 and commissioned in 2003. Shortly after that in 2005 the boats were to undergo extensive upgrades to the combat control system just to remain operational, although they also gained additional weapons capabilities like the Mk 48 ADCAP torpedoes.

With availability between 0 to 2 boats at any one time in the past few years, the RAN's submarine force only exist on paper. It is no wonder that the planning for the Collins replacement started as early as 2009, barely 6 years after the last boat HMAS Rankin was commissioned.



SSG-78 HMAS Rankin, the newest of the six Collins class SSK. Royal Australian Navy Photo.

 

 

 

 

 

Ship's Crest of all six Collins boats according to seniority from top to bottom. Source : RAN

Australia's SEA1000 Future Submarine Project




Boldly sailing into the sunset? HMAS Waller SSG-75 off the Fremantle coast in preparation for submarine escape and rescue exercise. RAN Photo

 

The SEA1000 Collins replacement project, otherwise known as the コリンズ級潜水艦更新計画 to the Japanese, aims to have the 6 troubled Collins Class conventionally powered submarines replaced by 10 to 12 boats by the year 2030 - 2040. It is expected to cost the Australian Government an estimated A$36 to A$44 billion. The four broad options they have would include :

- Buying military off the shelf designs. Though safest might not meet RAN requirements.
- Buying military off the shelf designs modified to Australian specifications and built in the country of origin. This mitigates some of the risks relating to both the design and the construction.
- Buying military off the shelf designs modified to Australian specifications and built in Australia. Deja vu.
- Commissioning a completely new design solely for the RAN built anywhere. Synonymous with kamikaze.

With the Collins fiasco still fresh in their minds, the Aussies naturally would want to focus on a proven design this time round. To have made the same mistake twice would be really moronic and unforgivable. So the most likely option to be selected would be the modified off the shelf design built elsewhere.

 Like I have mentioned in my previous article, there are not many options when shopping for a submarine as there are only a handful of exporters worldwide. In the past 20 years since the commissioning of HMAS Collins, the submarine's designer Kockums AB had become part of the German ship building conglomerate ThyssenKrupp Marine Systems (TKMS) through a series of mergers and acquisitions. The submarine's builder the Australian Submarine Corporation which initially started out as a joint venture between Kockums AB, the Australian Industry Development Corporation and 2 other private companies was also nationalised and is currently known as ASC Pte Ltd.

TKMS actually has a design that is supposedly catered for Australia's special needs in its subsidiary Howaldtswerke-Deutsche Werft's (HDW) Type 216 diesel-electric submarine. Although its design is somewhat based on the existing Type 212A used by the German and the Italian navies, the Type 216 is substantially bigger ( 4000 tonnes versus 1800 tonnes ) and has yet to be built. That alone would make it much lass palatable to the Aussies.



Artist's impression of the TKMS HDW Type 216 SSK Source : TKMS

To sum it up, Australia needs a conventional diesel-electric submarine (SSK) with almost the size of a nuclear powered submarine (SSN), this to enable it to have the range and endurance to patrol her vast coastline. Australia also needs it fast, like yesterday. Ok I exaggerate, by 2025 or thereabouts, when the first Collins boat are due to retire, not a lot of lead time by naval procurement timelines actually. Lastly Australia is looking for a proven design, and that sole candidate came from an until recently unexpected source - Japan with her Soryu class ocean going fleet submarine with air-independent propulsion (AIP), quiet, big, lethal, in operation since 2009.

As an added bonus to the Aussies, the Soryu class SSKs have onboard the Sterling AIP engine made by Kockums AB / TKMS so in that sense there would be some continuity with the Collins class should the Soryu be chosen. Japanese? Hey, these guys were building fleet carriers during our grandfather's time.

The History of Submarine Building In Japan

Japan has a long history in submarine construction which started as far back as 1904 when 5 Holland  Class submarines were bought from the United States of America. They were originally built at the Fore River Ship and Engine Company in Quincy, Massachusetts and shipped to Yokohama in knock-down kit form from Seattle. They were assembled at the Yokosuka Naval Arsenal (横須賀海軍工廠), then Japan's largest naval shipyard, with the assistance of an American naval architect Arthur Leopold Busch.



The first Japanese submarine of the Holland Class, aka Type 1 Submarine ( 第一型潜水艦 Daiichi Gata Sensuikan ). Photo : Wikipedia

 

That same year, the Kawasaki Dockyard Company or Kawasaki Zosensho (川崎造船所) as it is known in Japanese, purchased modified plans of the Holland Class submarine from the designer John Philip Holland directly and went on to build 2 boats with the help of 2 American engineers who had been Holland's assistants.

The following year, Japan bought 2 British C class submarines from the shipbuilder Vickers, Sons and Maxim and went on to assemble another 3 from kits at the Kure Naval Arsenal, Kure Kaigun Kosho (呉海軍工廠),, as it is known in Japanese. By 1909, Japan had launched her first submarine tender ( support / supply ship ) and had built a sizeable fleet of ocean going submarines before World War I had ended.

As one of the Allied victor countries at the end of World War I, Japan not only took control of the numerous German territories in the Southern Pacific like the Caroline Islands ( modern day Micronesia and Palau ) as mandated by the League of Nations, she was also given several captured German submarines as the spoils of war. This greatly accelerated her submarine design and building efforts and by the outbreak of World War II, the Imperial Japanese Navy (IJN) would have the greatest variety of submarines available for all sorts of mission. From fleet submarines that could cross oceans to transport and supply submarines, mine laying submarines, even aircraft carrying monsters like the 6500 tonne I-400, midget submarines that are designed to infiltrate naval bases and harbours and eventually to suicide submarines like the Kaitens towards the end of the War.



Kaiten Type 1 human torpedo displayed at the Yasukuni War Memorial Museum in Tokyo. Kaiten (回天) literally means return to heaven but the name actually originated from an older man-of-war of the Edo era, a wooden steamer known as the Kaiten Maru (回天丸). Photo : Wikipedia 

  

The I-400 sea plane carrier submarine. Note the aft deck gun and the crane for lifting the Aichi M6A Seiran seaplane (see below). Photo : Wikipedia

  

The Aichi M6A1 Seiran (晴嵐) seaplane. The I-400 can carry 3 of these seaplanes internally. One of the M6A actually carried out a bombing raid on continental US, attempting to start a forest fire in Oregon by dropping incendiary bombs. Photo : Wikipedia

 

Following her defeat in World War II, the naval yards in Sasebo, Kure and Yokosuka were either converted to commercial entities or became facilities to support and maintain the ships of the US Navy and the newly formed Japan Maritime Self Defense Force (JMSDF), also known as the Kaijojieitai (海上自衛隊) in Japanese. There was a lapse of more than ten years where Japan did not build any submarines. That changed in 1957 when the first generation Oyashio (おやしお) class submarine was constructed by the Kawasaki Heavy Industries in Kobe based on the old IJN I-200 design and some US innovations.

 

SS-511 JDS Oyashio ( first generation ) : The first post war Japanese built submarine. Source : Wikipedia

 

Since then, there had been several successive generations of diesel-electric submarines constructed by Japan, including the Oshio class (1963), the Arashio class (1964), the Uzushio class (1968), the Yushio class (1976), the Harushio class (1987), the new generation Oyashio class (1994) and of course the latest Soryu class (2005) with air-independent propulsion.




The new generation Oyashio Class SSK currently in service with the JMSDF. Photo : JMSDF




The new generation Oyashio Class SSK performing the emergency main ballast blow maneuver. Photo : JMSDF 

The Soryu Class SSK

The Soryu class submarine is the latest generation of conventionally powered hunter killer submarine with air-independent propulsion built for the JMSDF. It has a displacement of 2900 tonnes surfaced and 4200 tonnes submerged, the largest displacement of any submarine used by post war Japan. Although all previous generations of JMSDF submarines have been named after ocean currents ( 潮 shio in Japanese means current ), the Soryu class breaks away from this half a century old tradition by being named after auspicious mythical creatures, some of which might include the dragon, the phoenix, the pheasant and the kirin. In this case, the entire class is named after dragons (竜 ryu).

SS-501 Soryu ( そうりゅう, in kanji 蒼竜 ) Blue Dragon
SS-502 Unryu ( うんりゅう, in kanji 雲竜 ) Cloud Dragon
SS-503 Hakuryu ( はくりゅう, in kanji 白竜) White Dragon
SS-504 Kenryu ( けんりゅう, in kanji 剣竜) Sword Dragon
SS-505 Zuiryu ( ずいりゅう, in kanji 瑞竜) Auspicious Dragon
SS-506 Kokuryu ( こくりゅう, in kanji 黒竜) Black Dragon
SS-507 Jinryu ( じんりゅう, in kanji 仁竜) Humane Dragon
SS-508 Sekiryu ( せきりゅう, in kanji 赤竜 ) Red Dragon  ( named on 2nd Nov 2015 )

SS-509 is under construction and yet to be named. SS-510 and SS-511 are planned. Now I am no naval historian or ship naming expert but if I were to hazard a guess, likely names for these future boats may include Shoryu (翔竜) Flying Dragon, same pronunciation but in different kanji character, Shoryu (祥竜) Blessed Dragon, Hiryu (飛竜) Soaring Dragon, Tenryu (天竜) Heavenly Dragon, Kairyu (海竜) Sea Dragon.

Update 7th Jan 2017 - SS-509 had been launched on 12th Oct 2016 and is named the Seiryu ( せいりゅう, in kanji 清瀧, after 清瀧権現 Seiryugongen, the guardian goddess of a Kyoto temple ). The character 清 means clear but could also mean pure. So Pure Dragon be it. Note that 竜 and 龍 both mean dragon and could be pronounced as ryu. With three additional dots used to denote something to do with water, 瀧 could mean water dragon but is much more commonly used in everyday life to mean a waterfall ( 瀧 or 滝 pronounced taki ). Confused? Nevermind, that's Japanese for you.

Update 8th Nov 2017 - SS-510 had been launched on 6th Nov at KHI's Kobe facilities. It was named Shoryu, blessed dragon. Shoryu is expected to enter service with the JMSDF in 2019.

Note that the name Soryu had previously been used on 2 predecessors, including the World War II Imperial Japanese Navy fleet carrier the IJN Soryu, which took part in the Pearl Harbour Raid in Dec 1941 and was sunk during the Battle of Midway in Jun 1942.



The Soryu Class SSK underway. It has a conning tower with a shape resembling that of the Virginia Class SSN, minus the hydroplanes. JMSDF Photo.



Third of class SS-503 JDS Hakuryu arriving at Joint Base Pearl Harbour - Hickam, Hawaii for RIMPAC exercises.

Photo : USN / Wikipedia

 

Soryu Class Characteristics

Length : 84m
Beam : 9.1m
Draught : 8.5m
Displacement : 2900 Tonnes Surfaced
                         4200 Tonnes Submerged
Propulsion : 2 x Kawasaki 12V 25/25 SB-type diesel engines
                    4 x Kawasaki Kockums V4-275R Stirling engines ( air-independent propulsion )
                    producing 3900hp surfaced and 8000hp submerged

Speed : 13 knots Surfaced
             20 knots Submerged

Range : Unpublished but estimated at 6100 nautical miles at 6.5knots with AIP

Operational Depth : Unpublished but estimated at 500m.

Complement : 65 ( 9 officers 56 enlisted )

Radar : ZPS-6F Navigation / Surface Search Radar

Sensors : Hughs/Oki ZQQ-7B Sonar Suite with
               1x Bow Array
               4x Low Frequency Flank Array       
               1x Towed Array

Countermeasures :

ZLR-3-6 electronic support measures (ESM) system
2x 3 inch Underwater Countermeasure Launcher Tubes for acoustic device countermeasures (ADCs).                      
Torpedo Countermeasure System (TCM) for SS-508 and later

Communications :

X-band High Speed Satellite Communications Device for SS-507 and later

Armament :

6 HU-606 21 inch ( 533mm ) torpedo tubes with 30 reloads for the following
     
Boeing UGM-84C Submarine Launched Harpoon SSM
Mitsubishi Heavy Industries Type-89 Heavy Weight Torpedo
Mines

Construction :

Kawasaki Ship Building Industries, Kobe (川崎造船 神戸工場)
Mitsubishi Heavy Industries, Kobe (三菱重工業 神戸造船所)



SS-502 JDS Unryu being launched. JMSDF Photo.

The Soryu Class SSK in ceremonial light-up. JMSDF Photo. 

Soryu Class : A Formidable Naval Deterrence

The Soryu Class submarine is the world's largest submarine equipped with air-independent propulsion, and it has been in serial production since 2005, in other words, a well proven design. This represents a tremendous leap in capability for the JMSDF as they never had such AIP capable boats before. Collaborating with Kockums AB to licence produce the Stirling AIP engine was a smart move that allowed immediate access to a relatively risk-free proven technology. Kockum's proprietary Stirling Engine is a silent and vibration-free external combustion engine that had already been installed on the Gotland Class SSK and was also later retrofitted on the older Swedish Navy Vastergotland Class and Singapore Navy Archer Class SSK. The air independent propulsion system drastically reduces the need for frequent battery charging with the air breathing diesel generator which requires the submarine to be either surfaced or in snorkeling mode. It effectively increases the submerged endurance of the submarine and makes its detection much more difficult.

Its large displacement translates to having an extremely long range of close to 11000km, exactly what the JMSDF needs to patrol the vast open ocean between the Ryukyu Island Chain ( Okinawa ) and mainland Japan. For littoral operations, like patrolling the shallow Seto Inland Sea, the Soryu is fitted with an X rudder to provide high manoeuvrability to the submarine when operating very close to the seabed. This X rudder configuration was initially developed by Kockums for the Swedish A-19 Gotland Class SSK.




The X Rudder of SS-505 JDS Zuiryu seen clearly in this JMSDF photo.



Close-up view of the X rudder. Photo : Wikipedia

The quietness of the air-independent propulsion and the advanced sonar suite would allow the Soryu to stalk Chinese ballistic missile boats and SSKs with relative ease.

They are armed with Japan's Type 89 torpedo which is wire-guided with both active and passive acoustic homing modes and has very similar characteristics as the USN's Mk 48 ADCAP ( Advanced Capability ) heavyweight torpedo. With a diameter of 533mm, a length of 6.25m and a weight of 1760kg, this torpedo has a 267Kg High Explosive warhead. The effective range is said to be 27 nautical miles (nm) at 40 knots (kts) or 21 nm at 55 kts. The maximum speed is in the range of 70 kts and the operational depth is up to 900m.

These very same torpedo tubes can also launch the Boeing UGM-84L Harpoon Block II all weather, over the horizon, submarine launched anti-ship missile which also has a land attack capability. So the Block II Harpoon is essentially a cruise missile in disguise. It has a range of 124km and will post a serious threat to any Chinese or North Korean surface ship or land installations. It is guided by a GPS/INS unit and also has active radar terminal homing. The Block IIs being available to the USN since 1998, I am assuming that Japan has already either bought the newer version or had already upgraded her Block I Harpoons to Block II standard by now. South Korean certainly had!

The only glaring deficiency of the Soryu Class is the lack of Tomahawk tactical cruise missile launching capability. This is most likely a self-imposed limitation as the Post War Constitution forbids Japan from arming herself with offensive weapons.



RGM-84 the surface launched version of the Harpoon anti-ship missile being fired from the decks of the USN Arleigh Burke Class destroyer USS John S.McCain ( DDG-56). USN Photo

The First Post War Major Weapon System Export?

The 1947 Japanese Constitution is most famous for its renunciation for the right to wage war contained in Article 9. Its recent reinterpretation by the Abe government also allowed an easing of the self imposed blanket ban for arms export which had been enforced since 1976. It made possible the July 2014 agreement between Japan and Australia to partner on marine hydrodynamics ahead of a replacement for the Collins-class boats which quickly morphed into what might become an outright buy of 10 to 12 submarines from Japan.  If this export deal is realized, it would the first and most significant post war foreign military sales by Japan and is said to be worth about 20 billion dollars, hard cash which Japan desperately needs for rebuilding after the Tohoku earthquake and reforming to cater to a rapidly ageing population. It would also be a devastating blow to the Australian ship building industry who in my opinion really deserves losing the deal.

Although the Abbott government had previously said that the Collins replacements would be domestically built, consistent poor performance by the state-owned ASC on not only the entire Collins project and its subsequent upgrade works but also on the current Hobart Class air warfare destroyer project which is suffering from delays and huge cost overruns ( A$600 million over budget and 3 years late ), makes it much easier for them to justify an outright purchase from Japan.

Also, to have the Soryu built in Australia would incur a much higher cost, with some estimates at AS80 billion, almost double the original estimate of A$36 to A$44 billion. As Prime Minister Tony Abbott puts it, "The most important thing is to get the best and most capable submarines at a reasonable price to the Australian taxpayer". It would be really tragic if all that money is paid and the RAN gets another 12 Collins II instead. With the quest for precision and quality being almost a national obsession, you can be assured that anything that is made in Japan is nothing short of perfection. The Soryu Class will be no different. The Japanese worker takes tremendous pride in his work. The Aussies shall not regret that decision should Tony Abbott make that announcement by year end.

But all is not lost for the ASC. With the projected savings from buying directly rather than building domestically, there may be plans to fast track the Australian ship building industry by getting ASC to build new "super" frigates using the hull design of the 6500 tonne Hobart Class destroyer. ASC will likely get service and maintenance contract for the upkeep of the new boats.

The extra money saved could also be used to fund further purchase of the F-35 joint strike fighter which the Australian government had already pledged to buy. Another likely development could be the creation of a new submarine base, possibly at HMAS Coonawara in Darwin, New Territories, though I really do not know how *. With 12 boats projected, the current submarine base at HMAS Stirling in Perth, Western Australia will be swarmed. Having a northern base in Darwin will greatly reduce the transit time to the area of operations in South East Asia and the Australian East Coast.



Aerial view of HMAS Coonawara. Darwin City's CBD can bee seen in the background 2km away. RAN Photo.

* HMAS Coonawara is currently a small naval base supporting 8 Armidale Class patrol boats, within walkable distance of Darwin's central business district and close to the famous Doctor's Gully fish feeding attraction. The seabed will have to be dredged, the Larrakeyah Barracks and the marina next door will possibly have to be relocated to make way for the submarine pens.

Possible Modifications of the Soryu for SEA 1000

The operating range of the Collins Class SSK is in the region of 11830 nm (21000km) at a speed of 10.5 kts while that of the Soryu Class is about 6100 nm at 6.5 kts. The Aussies will likely want a bigger boat with longer range. The magnitude of increase may well be determined by whether a new submarine base is going to be built in Darwin.

The Aussies will also want "inter-operability" with their greatest ally the US Navy. So sensors and weaponry will have to be as identical as possible. The Type 89 torpedoes may have to give way to Mk 48 ADCAPs which the Americans use and which the RAN already has a stockpile of.



A Mark 48 ADCAP heavyweight torpedo being offloaded from the Los Angeles Class nuclear attack submarine USS Oklahoma SSN-723. USN Photo.

 

The ability to fire torpedo tube launched (TTL) Tomahawk Block IV cruise missiles on the Collins replacement could also be a likely modification. Unlike the Los Angeles Class Flight II boats and the follow-on improved Los Angeles Class boats which all have a 12 tube vertical launch system (VLS) for launching Tomahawk cruise missiles, the Soryu Class lacks such a capability. It would be expensive to integrate a VLS into a mature design if not technically difficult. Fortunately the TTL version exist and is currently used on the Royal Navy's Astute Class SSN.



Model of the Tomahawk Block IV tactical cruise missile. USN Photo.



Vertical Launch System (VLS) in the fore section of the Los Angeles Class nuclear attack submarine USS Santa Fe (SSN-763) Photo : USN

 

 

Final Words

The Collins project and the resulting 6 boats are a blemish to the proud reputation of Australian Navy and a disgrace to the entire ship building industry of Australia. It is a sad chapter in the long and illustrious history of the RAN that is best forgotten. The Australians should learn from their numerous mistakes committed in the past 2 decades and simply move on to the next chapter without making the same mistakes again. 12 boats sound like a huge fleet but I assure you it is not. Australia is Big, and the surrounding seas even BIGGER.

To Tony, please buy from the Japs, because if anything were to go wrong this time, it will be their problem, not yours.

To Abe the travelling salesman, you have done the sales pitch, please deliver well when the first order arrives, hopefully by Christmas. And may there be many more new orders for you to fulfill in the future.

Singapore Navy's New Submarines - HDW Type 218SG

*** Please read the latest on the Type 218SG here. ***

RSN's Silent Service

The Republic of Singapore Navy (RSN) had been operating conventional diesel-electric submarines since 1995. Initially, as it was a completely new capability for a small navy, the RSN opted to purchase 5 decommissioned / used submarines from Sweden. These were the A-11 Sjöormen class submarines first commissioned in the late 1960s. Four of these boats were re-commissioned as the Challenger class and the fifth was to be salvaged for parts. They were extensively refurbished and upgraded by Kockums for use in tropical climate and came with personnel training agreements with the Royal Swedish Navy. They form the 171 Squadron based at Changi Naval Base.

The Challenger class submarines enabled the RSN to learn the trade of undersea warfare in an accelerated timeframe but they had one glaring shortcoming - they were not equipped with air-independent propulsion (AIP). AIP is simply an advanced underwater propulsion system in a non-nuclear submarine that did not involve access to atmospheric oxygen, eliminating the periodic need to surface or snorkel to recharge the batteries. ( see my previous blog AIP submarines for RSN )

In 2005 an opportunity to buy another 2 decommissioned submarines from Sweden came in the form of  two A-17 Vastergotland class boats. These were a generation newer than the Challenger class boats, having been launched in 1986 and 1987. They were extensively modified  and had their hulls sliced and lengthened to accommodate a proprietary Stirling AIP engine. They were eventually commissioned as the RSS Archer and RSS Swordsman.


 

RSS Archer during her launching ceremony in Sweden in June 2009. Source : Peter Nilsson Kockums AB.

 

 

The Stirling Conversion : From Vastergotland to Archer. Kockums picture

 

Submarine Shopping

Now that the submariners have honed their skills with AIP, it is time for the RSN to consider buying more potent and newer platforms. On 2nd Dec 2013 MINDEF made public the acquisition of 2 customized AIP capable submarines from ThyssenKrupp Marine System GmBH (TKMS). From the MINDEF press release " These submarines, together with the Archer class submarines, will replace the ageing Challenger class submarines. The Challenger class submarines were built in the 1960s and will be progressively retired from service. The replacement submarines will have significantly improved capabilities and be equipped with Air Independent Propulsion systems." With some background information, it would not be of too much a surprise that this time it would no longer be a Swedish design.

Boat Supplying Nations

There are not many countries that have the capability to design and build submarines. The United States have not looked back on conventional diesel-electrics ever since they commissioned the world's first operational nuclear submarine the USS Nautilus (SSN-571) in 1954. The Royal Navy similarly disposed off their Upholder class SSKs and are and all-nuclear force. What's left will be Germany, with their U-209s and U-214s, probably the largest exporter of conventional submarines in the free world, France, the supplier of Scorpenes, Spain, exporting their S-80 Scorpene variant, Sweden, with their ill-fated Collins-class project but enjoying better domestic success and in exporting to Singapore, and finally Russia, with the Project 636 improved Kilo class. Japan is just beginning to come online as a potential supplier, after ditching their post WWII pacifist Constitution. South Korea builds U-209s and U-214s under licence and exported a couple to Indonesia, and China builds but hardly exports. All said, if you are buying U-boats ( presumably non-nuclear ), your options are somewhat limited. If you are sourcing for nuke boats then your choice is simple, go to Uncle Putin, but be warned, you can get badly mauled like India did with its yet to be delivered INS Vikramaditya ( ex-Admiral Gorshkov ) carrier.

The Boote Yards

Kockums AB's Karlskrona shipyard has been producing first rate submarines for Sweden since the 1912. Apart from the A-11 Sjöormen class and the A-17 Vastergotland class SSKs already mentioned above, they also constructed three A-19 Gotland class submarines with air-independent propulsion for the Swedish Navy in 1990. Their next generation offering is the A-26 submarine, originally scheduled to replace the Vastergotlands as they are retired in 2020.

In a series of miscalculations by the Swedish government, the fortunes of Kockums began to change around the turn of the century (1999 to be precise) where, in a complicated web of industrial merger and acquisition, Celsius AB sold its subsidiary Kockums AB to German ship builder Howaldtswerke-Deutsche Werft GmBH (HDW) in an all-share swap for 25% of HDW, with an option to exit the business with a lump sum. The following year, SAAB bought over most of Celsius AB and opted to be paid and exited. And so Kockums become a part of HDW and then HDW was itself acquired by ThyssenKrupp Marine System GmBH (TKMS) in 2005.

HDW is of course most famous for submarines - their U-205, U-206 and U-209 series conventional diesel-electric submarines are in active service in many navies all around the globe, not to mention the Dolphin Class variant for the Israeli Navy. Their latest offering is the U-212A and its export version the U-214.

TKMS is a huge German conglomerate and in addition to Kockums which it acquired through HDW, owns several other shipyards in Germany and Greece. It now has two competing lines of submarines to sell in a limited post-cold war global market and the number of submarine exports are just not enough to keep the yards busy. It does not help when many customers also insist on local construction and technology transfer. It just not possible to maintain both the German HDW and Swedish Kockums to compete against its rivals like DCNS of France and Rubin Design Bureau of Russia. Understandably TKMS would favour its German shipyards over the other foreign ones.

So when the time came for Singapore to replace her Challenger class submarines, Kockums, the exclusive supplier of submarines to the Republic of Singapore Navy for the past 18 years saw its monopoly broken and was prevented from submitting a bid by its parent company. Instead, TKMS offered HDW's U-218SG, to be built in its Kiel shipyard in northern Germany.

On a separate note, TKMS had also successfully stalled Kockum's next-gen A-26 AIP offering to the Swedish government which industrial insiders believe is delayed by contract negotiations between Kockums and Sweden's Defence Materiel Administration. The two parties simply cannot come to a price agreement.

Fortunately, this impasse may be about to change as Singapore's HDW purchase had finally whipped the Swedes into action to ( forcefully? ) buy back Kockums and regain control of their submarine building capability and put the A-26 acquisition back on tract. In what has come a full circle, on 29th Jun 2014 SAAB announced that it will buy Kockums back from ThyssenKrupp for SEK 340 million ( about USD 50.5 million) in a deal that is probably subsidized by the Swedish government. Still, the U-218SG purchase is a done deal and the A-26, severely undermined by ThyssenKrupp, will never be ready by 2020 even for its domestic client, the RSwN.





The Kockums next generation submarine the A-26 AIP that the RSN
was never meant to have in a computer generated image showing
 special forces deploy through the Multi-Mission Portal. Source : SAAB Kockums

 

 

The Mysterious U-218SG

All that we know about this submarine is that it is a customized design for Singapore. It is a conventional diesel-electric hunter-killer submarine with air-independent propulsion based on HDW's current designs, due for delivery in 2020. No other information is available in the public domain about this new boat. Unless you have insider information, right now everything is speculation.

Still, there is nothing to stop anyone from making an intelligent guess as to what this new submarine would turn out to be. A good start will be to understand Singapore's operational requirements and the currently available HDW U-boats designs.

The U-218SG will likely be involved in the following :

Anti-surface and anti-submarine operations

Special forces deployment

Unmanned vehicle deployment ( UUV and UAV )

Land attack missions with cruise missiles

Intelligence, surveillance, target acquisition and reconnaissance ( ISTAR )

Carrier battle group ( CVBG ) escort - future Endurance-160 type large helicopter / F-35B carrier

Singapore's existing Challenger and Archer class SSKs are in the 1200 to 1400 ton range and are really too small to cope with all of the above functions. Even the existing HDW options, the Type 212A built for the Deutsche Marine ( German Navy ) and the Marina Militare ( Italian Navy ), as well as the export version the Type 214 are all in the 1500 to 1700 ton range.

Unlike European navies who operate in the relatively smaller and shallower Baltic Sea, the Mediterranean Sea, North Atlantic Ocean and the North Sea, those in the Indo-Pacific region including Japan, South Korea, India and Australia would probably require bigger submarines with much longer range. The main role of the U-218SG will surely not be to play cat and mouse with the RMN in the narrow Straits of Malacca. It might have a bigger role in maintaining the SLOC open in the South China Sea and beyond, given the aggressive behavior of China in recent years. So it has to be bigger with a longer range and endurance. It also has to be faster, at least as fast as the carrier task group that it is supposed to protect. A bigger submarine will also have more space for more comfortable crew accommodation.

Fortunately HDW has exactly such a design concept in the form of the Type 216 AIP weighing in at 4000 ton. This is a double hulled two decked ocean-going monster was designed to fulfill the requirements for the Australian SEA 1000 Collins replacement project. However, it would be too big for the RSN if the design is adopted at face value. It would never safely transit the congested waters of the Straits of Singapore without being observed ( or bumped into )! So perhaps 2500 to 3000 tons would be a good compromise. A scaled down U-216 while retaining all the original bells and whistles. There is precedence in the Project Delta frigates - the Formidable class being an improved but smaller version of the La Fayette class stealth frigate.






The HDW U-216 SSK Source : ThyssenKrupp Marine Systems

 

 

This is the original U-216 technical specifications :

Length : approximately 90m

Pressure Hull Diameter : approximately 8.1m

Surface Displacement : about 4000 tons

HDW Fuel-cell Air-Independent Propulsion System

Lithium-Ion Polymer Battery Technology

HABETaS rescue system for personal rescue / free ascent at 300m

Endurance : 80 days at sea. 4 weeks without surfacing.

Range : 10000 nautical miles

Compliment : 33 officers and ratings. Extra capacity for divers and attached personnel

IDAS fibre-optic guided missile system for defense and attack against aerial targets ( ASW helos included )

Weapon Tubes : 6 x 533mm ( torpedoes, anti-ship missiles, mines, UUV? )

Vertical Launch System : Vertical Multi-Purpose Lock for launching cruise missiles

Torpedo Countermeasure System

Special Forces Swimmer Delivery Vehicle ( SDV )

In other words - the works. All that anybody could ask for in a submarine short of SLBM launch capability.

The innovative Interactive Defence and Attack System for Submarines (IDAS) is a

lightweight fibre-optic guided missile for submarines against aerial threats.
Photo : ThyssenKrupp Marine Syatems

                                

 

 

The MdCN ( Missile de Croisiere Naval ) or naval cruise missile can be

launched from the torpedo tubes of a submarine. Source : MBDA

 

 

The MdCN, aka naval SCALP, can also be launched from the
A70 Sylver vertical launch system of France's FREMM frigates. Source : MBDA

 

Whatever the final specs are, it will be a huge step forward for the RSN. Retirement of the Challenger class submarines will transform RSN's silent service into an all-AIP force, just like the Swedes and the Germans. No ship lasts forever. If all goes well, tranche one will be followed with a subsequent order to eventually replace the Archer class possibly by the year 2025 - 2028. This article may be updated as more information is forthcoming.

AIP Submarines For RSN



The New Archer-Class ( ex-Vastergotland Class ) Submarine



HMS Sodermanland was a Vastergotland-class SSK that was upgraded in 2003 with AIP.
Seen here in a 2010 photo. Photo via Wikicommons




In case you do not know, RSN stands for the Republic of Singapore Navy. The RSN has been operating submarines since 1995, when a total of 5 ex-Swedish Navy A-11 Sjöormen Class SSKs ( Diesel-electric Attack Submarines ) were acquired when they were being retired by the Swedes. These old boats were all launched between the years 1967 to 1968 making them more than 25 years old when they were sold to Singapore.

However, they were extensively refurbished and modernised by Kockums AB of Sweden ( now SAAB as of 2015 ) for operations in tropical climate before being re-commissioned for the RSN as the RSS Challenger Class submarines. Four of these boats form the backbone of the 171 Squadron while the fifth boat is cannabilised for spares.

The RSN subsequently acquired another 2 submarines from Sweden in late 2005, the A-17 Vastergotland Class SSK, which had been retired from service by the RSwN ( Royal Swedish Navy ). Again, Kockums AB was engaged to refurbish these submarines. At that time little else was announced about the deal, especially whether the refurbished boats will have Air-Independent Propulsion (AIP) technology*. Today, 16th Jun 2009, the public learnt from the daily newspapers and MINDEF releases that these two boats are the RSS Archer and RSS Swordsman. RSS Archer has been launched at Kockums AB yard at Karlskrona by Mrs Teo Chee Hian, wife of the DPM / Minister for Defense.

Swedish newspapers reported that the Vastergotland deal was worth SEK 1 billion, then equivalent to US$135 million.
 



Launch of the RSS Archer at Kockums Shipyard in Karlskrona 16th Jun 2009.
Photosource : Kockums AB Photographer : Peter Nilsson 

What is Air Independent Propulsion?

AIP is simply a non-nuclear submarine propulsion system that works without requiring an external supply of air. It allows a conventional ( non-nuclear ) submarine to remain submerged for a longer period of time compared with their diesel-electric cousins as the AIP engine negates the need for an external supply of air / oxygen.

 

Diesel-electric submarines have batteries that need to be recharged by their diesel engines every now and then when they are depleted. Running the diesel engines require air / oxygen that can only be supplied when the submarine is either on the surface or when it is snorkeling. When snorkeling, the submarine stays submerged just beneath the surface but sticks its snorkel mast up to suck in air and expel diesel exhaust.

These activities put the submarine at increased risk of being detected by visual or infra-red sighting, radar reflection from the snorkeling mast or conning tower, magnetic anomaly disturbances or by the acoustic signature of the noisy diesel engines.

With AIP, all of the above risks normally associated with battery recharging will be eliminated. It allows the submarine to remain submerged for 2 weeks or more and makes the AIP submarine much stealthier than its diesel-electric counterpart.

The AIP Integrator

Kockums AB is the Swedish shipyard owned by Germany's ThyssenKrupp Marine Systems after a series of mergers and acquisitions starting from 1999. They have been building quality submarines for Sweden since 1912 and were the first in the world to produce a purpose-built AIP submarine the A-19 Gotland-class. While the RSwN retired the HMS Vastergotland and her sister ship HMS Halsingland, it chose to upgrade the newer two ships, the HMS Sodermanland and the HMS Ostergotland to being AIP capable using Kockum AB's proprietary AIP Stirling Engine. Kockums basically cut the submarines into two at mid section and lengthened the hull to accommodate the new Stirling Engine. The Stirling AIP uses diesel and oxygen in a closed system. The upgrade is so radical that the 2 boats are considered a new class of their own - the Sodermanland Class.

 

 

Royal Swedish Navy : All AIP Fleet

 

With the completion of the Sodermanland-class upgrade, the Royal Swedish Navy became the only navy in the world to have an entirely AIP capable submarine fleet. Nobody else could have that claim. Who else better to turn to when you need AIP submarines than the Swedes? They are the experts!

The A17 HMS Vastergotland ( left ) and the more advanced
A19 Gotland-class HMS Uppland  along side at Malmo, Sweden.
Photo taken in 2003 before the Vastergotland was sold to Singapore. Wikicommons



HMS Sodermanland and the submarine rescue ship A-214 HMS Belos in 2003. Wikicommons

 

Blue Water vs Brown Water

The US Navy commissioned the world's first operational nuclear submarine the USS Nautilus (SSN-571) in 1954 and never looked back. Their last batch of conventional diesel-electric submarine, the Barbel-class, was ordered between 1955 to 1956 and all had been retired by 1990. They now have an exclusively nuclear underwater fleet which is extremely effective for blue water ( open ocean ) operations which require long endurances. The Swedes however, have vastly different requirements where they have huge swaths of coastlines with deep narrow fjords to patrol. The salinity and temperature of the Baltic Sea are also very different from that of the open oceans and therefore the Swedes have long settled with conventionally powered submarines.
 

Singapore is a littoral state with plenty of shallow, murky waters and busy, noisy sea lanes. The small Swedish SSKs are well suited for this kind of underwater environment. Besides, modern diesel-electric submarines, like the Russian Type 636 improved Kilo Class SSK, can be extremely quiet especially when they are drifting or moving very slowly ( less than 5 Knots ). In fact, the RSwN HMS Gotland was "leased" to the USN for 2 years between 2005 to 2007, complete with crew, for bilateral anti-submarine exercises. Uncle Sam will not need to practice ASW with HMS Gotland if it was not quiet!

Growth of RSN's ASW Capabilities

The Anti-Submarine Warfare (ASW) capabilities of the RSN has grown in leaps and bounds ever since its early days of operating the Seawolf-class missile gunboats ( since retired ). In the 80s came the Victory Class missile corvettes with their variable depth sonar and Whitehead Alenia torpedoes. The 90s saw the addition of the Fearless Class ASW Patrol Vessels and of course, the best ASW platform, the Challenger Class SSKs.
The missile corvettes and the patrol vessels are both too small to accommodate any ASW helicopters. That glaring deficiency has since been rectified with the purchase of the Formidable Class stealth frigates which will carry the Sikorsky S70B Seahawk ASW helicopter, assumingly with magnetic anomaly detectors and towed array sonars plus offensive weapons like the mk46 torpedoes.
With the commissioning of the RSS Archer and Swordsman due in ?2010/2011, the RSN will have AIP technology among its submarine fleet and significantly increase its reach.
We must also not forget the aerial assets of the RSN, the Fokker F50 maritime patrol aircraft, in operation with the 121 Squadron since 1993, which acts as a force multiplier when dealing with naval threats.




What Singapore's Neighbours Have or Are Acquiring

The Malaysians have received their first of 2 Scorpene Class SSK earlier this year, the KD Tunku Abdul Rahman. These Scorpenes are not AIP endowed, unlike their more capable Spanish S-80 / S-80A cousins with the MESMA AIP engine which uses ethanol and compressed oxygen. They have another older Agosta B SSK based in France for training purposes. Since these were bought in 2002 during Malaysia's M-Era, the officially stated RM3.4billion package came with certain landing rights at the Charles de Gulle Airport for MAS as well. Maybe they could have had 3 scorpenes for the same price ( or 2 scorpene basic-AIPs ) had they not insisted on those landing rights, or having to pay the hundred over million ringgit of brokerage fees, or.... I digress. The second boat KD Tun Razak is due to be commissioned later this year.

The Indonesians have 2 ageing Type 209 / 1300 Cakra Class SSK since 1981. They have been recently upgraded by the South Koreans who also operate the Type 206 / Type 209 submarine. The Type 209 is one of the most widely exported submarine from the West. They have made an agreement with Putin in 2007 to buy among other things, 2 Type 636 Kilo Class SSK plus options for another 8 more. These orders have yet to be fulfilled.

Thailand has no submarine fleet but are eager to acquire one. Earlier efforts by Sweden to sell them the A19 Gotland Class submarine have failed to materialise. Most of the money could have gone into financing their purchase of the 12 SAAB JAS-39 Gripen fighters and the 2 SAAB S-1000 Erieye AEW. Air Force 1 Navy 0.

Vietnam has 2 ex-Yugoslav minisubs for special forces operations and has recently ( Apr 09 ) agreed in principle to buy 6 Russian Type 636 Kilo Class SSK. Pegged at USD1.8Billion these are said to be originally the ones ordered by Venezuela, but with Hugo Chavez's falling oil fortunes are now going to Vietnam.

Australia has 6 Type 471 Collins Class Diesel-electric SSK designed by Kockums AB. These are among the world's largest non-nuclear submarines displacing 3350tons submerged suited to patrolling the vast coastlines of Australia. They are quiet and capable boats with a large weapons load including the Boeing Sub-Harpoon anti-ship missile and the Mk48 ADCAP torpedoes. They can be retrofitted with AIP engines. Following a bad start with lots of delays and deficiencies, these boats have been upgraded with a combat control system from Raytheon similar to the one in the Virginia Class SSN of the US Navy.

The New Zealanders are on good terms with the Aussies and do not have any perceived threats in their immediate vicinity. The Helen Clarke Government retired the last of their 1950 era McDonnell Douglas A-4Ks without any replacement. Their air force now only operates helicopters and transports. The RNZN does not own any submarines.

The Future

What next after the RSS Archer? The RSN will probably retire part of its Challenger Class fleet upon arrival of the RSS Archer and RSS Swordsman. They can be mothballed or be used as a training submarine or be cannibalized for spare parts. Once its AIP operational experience has been gained, it can either look to acquire the A-19 Gotland Class when the Swedes are ready to retire them or consider other advanced options like the German HDW U212 / U214 AIP SSKs or the Russian Amur 1650 / Amur 950 / Kilo SSKs or God forbid, the DCNS / Navantia Scorpene SSK.

Update 2013

RSS Archer and Swordsman have both been commissioned. The 4 older Challenger Class submarines are still operational. There are now rumours that RSN could be interested in the latest Swedish A26 Class submarine.

The Collins Class SSKs of Australia is still plagued by generator and sonar problems. Only one out of six ship is currently operational. The RAN is looking to acquire 12 new enhanced-Collins type submarines as their replacement.

Indonesia bought 3 Type 209 / 1400s from South Korea.

Malaysia has received Exocet missiles with land attack capabilities for their Scorpene submarines, range about 180km .....

Update 3rd Dec 2013

In the Straits Times : The Republic of Singapore Navy will be acquiring 2 customized Type 218SG AIP submarines from HDW Kiel. They are likely to be ready by 2020. Two of the older Challenger class non-AIP submarines will be retired.