April 24, 2015

Soryu - Lithium-ion battery Revolution from 2022?

The following is mainly drawn from discussions between "S" and Pete on the Comments thread for Air Independent Propulsion (AIP) Issues of April 23, 2015. A big thankyou to S for doing the estimates and providing other comments. 

S advises that originally Stirling AIP was unpopular in the Japanese Navy, because of its low power (2.5knots) and complicated operation. For Japan AIP was only a temporary measure on the Soryu until Lithium-ion batteries (LIBs) became a more mature technology.

Looking at the Table at the bottom of this article you will see the first tranch/group of what may eventually be 12 Soryu submarines are known as “16SSin red. 16 is the last two digits of the Soryu’s first of class’s “Building no. 8116” and “SS” means conventional submarine. The “Soryu” 16SS was commissioned in 2009. 16SS is diesel-electric with lead-acid batteries and Stirling AIP.

Published figures for 16SS range/speed (see sidebar of Wiki) would most likely be for semi-submerged snorkel/snorting mode. 16SS fully submerged (no snorkel use) figures are classified but S’s estimate for submerged speed and endurance is 6 knots for 3 days.

The aim of S's input is to give an estimate for the fully submerged range/speed of the second tranche of Soryu’s further down the Table, known as 28SS in red. The first of class 28SS may be commissioned in 2022. It will not have AIP but instead will have new Lithium-ion batteries (LIBs).

As a yardstick for comparision the Collins submarine, has lead-acid batteries totalling 400 tonnes. Its range/speed is 480 nautical miles at 4 knots

S estimates 28SS submerged speed/range and duration may be 5,040 nautical miles at 7 knots for  30 days.


This 28SS estimate is based on a Japanese Navy (Japan Maritime Self-Defense Force (JMSDF)) estimate 10 years ago that LIBS have 1.5 times to twice the capacity and power (or is that twice the capacity and 1.5 times the power?) of lead-acid batteries.

While 16SS has AIP space and can carry only 500 low capacity lead-acid batteries (cells?) the 28SS will probably have five times more battery space = 500 LIBs + 2,000 LIBs in the space that used to house the AIP = 2,500 LIBs.

On the assumption that the submerged speed for 16SS is 6 knots and knowing power is proportional to the cube of velocity. Submerged speed for 28SS = 6 knots x 1.15 (cubic root of 1.5) = 7 knots.

Assuming the submerged duration for 16SS is 3 days the submerged duration for 28SS = 3 days x 2 (capacity ratio of 28SS/16SS) x 5 (batteries ratio of 28SS/16SS) = 30 days

Submerged range for 28SS = 30 days x 7 knots x 24 hours = 5,040nm.


One must remember that the above are estimates based on several assumptions. Still, it indicates much greater submerged performance for the second tranche of Soryus (28SS) that will come into service from 2022.

Australia would want a transit speed (Fremantle to around Darwin and alternatively Freemantle to Sydney) of perhaps 12 knots. After that an Australian sub may rely on much more fully submerged LIB use in order to stay out of view of Chinese satellites (keeping away from Chinese undersea sensor arrays is another problem).

Variables that are difficult to predict are whether the next tranche of Soryus (28SS) is larger or smaller than 16SS or whether Japan may build an Australia-only version.

LIBs may well surpass expectations ever considered for AIP. But they still will not compare to the performance of nuclear propulsion. 

S used the following two web documents when doing the estimations:

-  http://en.wikipedia.org/wiki/Drag_(physics) , “Drag at high velocity”“Power” (in fluid dynamics 6 knot/h is high velocity).

-  https://samueldavey.files.wordpress.com/2013/04/fluid-dynamics-submarine-report.pdf an Australian Maritime College paper of 30 pages. This is especially interesting. It draws on Australian Defence Science and Technology Organisation (DSTO) findings. It explains why submarines are shaped as they are and what modifications can make them move more efficiently.

For further information on LIB issues and other Soryu issues see many more articles on Submarine Matters, including:

MHI and KHI not at Australia's Future Submarine Summit, Adelaide, March 24-26, 2015 of March 24, 2015.



        Building no.Pennant no.Name/NamesakeLaid downLaunchedCommissionedBuilt By
16SS 8116SS-501Sōryū (そうりゅう) / Blue Dragon31 March 20055 December 200730 March 2009Mitsubishi
   8117SS-502Unryū (うんりゅう) / Cloud Dragon31 March 200615 October 200825 March 2010Kawasaki
8118SS-503Hakuryū (はくりゅう) / White Dragon6 February 200716 October 200914 March 2011Mitsubishi
8119SS-504Kenryū (けんりゅう) / Sword Dragon, Stegosauria31 March 200815 November 201016 March 2012Kawasaki
8120SS-505Zuiryū (ずいりゅう) / Auspicious Dragon16 March 200920 October 20116 March 2013Mitsubishi
8121SS-506Kokuryū (こくりゅう) / Black Dragon21 January 201131 October 2013(March 2015) Kawasaki

8122SS-507Jinryū (じんりゅう)/ Benevolent Dragon14 February 20128 October 2014(March 2016) Mitsubishi

8123SS-508 ?2013?2015? 2017?) Kawasaki

8124SS-509 ? 2014?2016?  2018? Mitsubishi?

8125SS-510 ? 2015?2017? 2019? Kawasaki
28SS   8128      SS-513     ?                                           2018?          2020?          2022?            Mitsubishi?  

Again thankyou S for doing most of the work :)



April 23, 2015

Air Independent Propulsion (AIP) Issues


On the Comment thread https://www.blogger.com/comment.g?blogID=19245896&postID=5077212490045962874 Anonymous on April 9, 2015 asked:

"I have few questions to ask you about submarines, what is actually air independent propulsion system of non nuclear submarine. There are many types of AIPS technology in the world and few are under development too so can you tell me which is best among these. And is it possible for a submarine with AIPS system to perform same like a nuclear submarine. I heard recently in a article talking about future diesel submarine will be capable like nuclear submarine with support of latest AIPS system."

On Comment thread https://www.blogger.com/comment.g?blogID=19245896&postID=6049042900970745217&page=1&token=1429705517253 another Anonymous on April 21, 2015 asked: ""why would you want the AIP removed from TKMS Type 214 for Australia?"

"S" has provided useful comments, included in the text and Comments thread


At some stages-usually a submarine will draw air/oxygen (while near the surface) through its snorkel to power its diesel engines. The submarine's batteries can then be recharged. For a limited time Air Independent Propulsion (AIP) technology makes snorkel air/oxygen drawing unnecessary.

AIP provides diesel-electric submarines with greater submerged endurance (several weeks as opposed to just several days (on existing lead-acid batteries)) and very quiet operation. This enhances a submarine's survivability and mission flexibility. AIP systems use limited amounts of stored (chemically, liquid or compressed) oxygen or hydrogen fuel.

AIP involves chemical changes and sometimes moving parts. My article Air Independent Propulsion (AIP) Technologies and Selection of August 5, 2014 which has diagrams, addresses questions on how AIP systems work. Basically the most developed AIP systems were/are made by 3 Western European countries centred around the North Atlantic and Baltic Seas. These are:

- German fuel cell AIP offered in German TKMS-HDW's latest submarine designs (214s, KSS-IIs, Dolphin 2s, probably 218s, offered for the future 216).
- Swedish Stirling AIP submarines (in Swedish Kockum's designed Gotland, Södermanland and Archer classes, Japan's Soryu class and China's Yuan class)
- French MESMA AIP (just on 3 French DCNS designed Agosta 90B submarines operated by Pakistan). Offered for France's newer Scorpene submarines (no takers?). MESMA and a second generation AIP are probably being offered to Australia within a offered SMX Ocean/conventional Barracuda. It is unclear whether Brazil's 4 future Scorpenes will have AIP.

Based on sales numbers and different countries buying them, Germany's fuel cell AIP and Sweden's Stirling AIP have been the most successful.

Countries that have recently announced plans to develop AIP include: Russia, Spain, India (DRDO) and France indicates it may develop a "second generation AIP". Possibly Japan and South Korea may develop indigenous AIP systems.

Different countries and different submarines builders will claim that their AIP is best. But these are  commercial claims. It depends what the customer country wants, what they actually need - all dependent on their typical mission profiles. Technological advances (such as Lithium-ion batteries and evolving anti-submarine sensors) also influence the value of AIP products. 

Any comparison/claim that AIP is like nuclear propulsion is a commercial or government/Navy sales pitch. It is like comparing a conventional high explosive bomb with a nuclear weapon. Nuclear propulsion can drive a submarine continuously at 30 knots for 3 months (only limited by food stocks for the crew). In comparison AIP technologies might only move an operational submarine (with full warload) at slow speed (4 knots?) for 3 weeks (?). Higher performance AIP systems may be possible but there might be major downsides eg. their stored explosive hydrogen and/or oxygen might make them too unsafe to be a usable weapon system.

Additional discussion of AIP issues comes by way of my response to Anonymous April 21, 2015 question "Why would you want the AIP removed from TKMS Type 214 for Australia?":

Australia might not want AIP because: 

-  AIP is not a standard inclusion for all new diesel submarines. Inclusion of AIP depends on a customer navy's typical mission profiles. Within the Type 214 a fuel cell AIP seems to be a compulsory sales inclusion that many countries don't need.

- AIP is ideal for countries with mission profiles that value 2 to 3 week submerged-slow or zero speed (sitting on the sea bottom). Some countries, like Sweden or Germany, when in the Baltic Sea, (or Singapore near its area) might have only 2 to 3 day missions when AIP alone may be sufficient. 

Australia's mission profile is very long distances, warm water, fast transit, then perhaps mainly medium speed patrolling. This places more value on efficient conventional diesel-electic operation which would not be at the expense of weighty AIP inclusion.

Also technological advances are trending toward submarines using Lithium-ion batteries (LIBs). Issues of relative energy efficiency AIP - batteries compared to LIBs - and LIBs compared to other batteries are very complex. See page 6 of this publication http://navyleague.org.au/wp-content/uploads/2012/06/The-Navy-Vol_70_No_4-Oct-2008.pdf for a brief discussion of the relative capacity. 

The newest batch of Soryus are believed not to have Stirling AIP but instead have LIB to cover slow-medium, prolonged, submerged operation. See S's calculations in the Comments thread

AIP's other possible downsides include:

- it is very expensive to incorporate into new build submarines or to retrofit - often amounting to one third of the submarine's price.

- non-replenishable during a mission

- very unsafe, flammable, even explosive, "S" reported, April 22, 2015 that "I agree about weak points of hydrogen fuel cell system for submarine. Submarines of this type are safe under the ordinary or non battle situation, but most important thing is safety under the battle situation with strong vibration or shock. Even if hull is not damaged, if slight hydrogen leakage is caused by tiny damages of piping system including valves, pressure gauges and joints, the submarine becomes perfectly dysfunctional. Because concentration of explosion limit for hydrogen is very low, you must avoid any kinds of stimuli as such heat or electrical ignition which cause explosion. And in the case of accident with hydrogen leakage, perhaps you cannot rescue the submariners by hull cutting with ignition."

- AIP involves weight tradeoffs. The weight taken up by AIP may in an Australian submarine be considered better used for extra batteries or diesel fuel.

- can break down (especially if it has moving parts like Stirling AIP)

- may be more efficient in cold water rather than Australia's mainly warm operating areas

For all these and other reasons AIP was never placed in the Collins sub - even though the Swedish-Kockums designers specialised in AIP subs.


April 21, 2015

Vietnam's (Russian speaking) Kilo Submarine Service at Work and Play

An unintentionally funny submarine article!? They are rare. This article is very interesting concerning the perceived importance of Russian language training and importance of instilling group feeling in Vietnamese Kilo submarine crews. I wonder if it would be true to say that the Vietnamese are natural soldiers and sailors - given all the wars-threats they've had to face. With Russian and Chinese help Vietnam beat the US and Australia and other Coalition allies by the early-mid 1970s (though few here will admit it). Russia, the US and India are now all involved in establishing closer relations with Vietnam - for economic reasons and as part of a wider contain China strategy. The following article is a rare gem.

http://tuoitrenews.vn/ ("The News Gateway of Vietnam") reports, April 21, 2015  http://tuoitrenews.vn/features/27604/life-at-kiloclass-submarine-brigade-in-vietnam


Life at Kilo-class submarine brigade in Vietnam
UPDATED : 04/21/2015 08:58 GMT + 7

Tuoi Tre (Youth) newspaper contributor has expressed her marvel at the wholehearted dedication, rigorous training, and diligent study of the Russian language among the sailors stationed at a submarine base in central Vietnam after a recent visit.
The Tuoi Tre contributor narrated her memorable experiences during her trip to Submarine Brigade 189 under the Vietnam People's Navy.
The brigade is based in the Cam Ranh Military Port, which is situated in Khanh Hoa Province.
Before the brigade was founded in June 2011, selected soldiers joined a training course in Russia in October 2010 prior to passing on what they had learned to their colleagues and juniors at home.
However, rigorous training began well before that.
Over 30 years ago, Submarine Regiment 196 came into being and boasted well-qualified human resources.
Many members of the regiment's force were later transferred to the current Submarine Brigade 189.
Younger recruits to the brigade all excel in technical training, have good physique and stamina, and cope well under pressure.
One of the initial challenges involved newcomers spinning over 100 times and they were requested to regain balance shortly after the spinning came to a stop.
They also took on an immense challenge which required them to stay in a compressed air chamber with its pressure equivalent to that at a depth of 50 to 70 meters.
Such strenuous challenges now become their everyday routines.
[Training in dispute management aboard the sub!]
Submarine sailors are pictured during their everyday routines. Photo:Tuoi Tre
However, the sailors' arduous physical training did not surprise theTuoi Tre contributor as much as their single-minded devotion to honing their professional skills and command of Russian.
During her trip to the Russian-supported Submarine Training Center, which is located inside the Cam Ranh Military Port, she was amazed at the perplexingly intricate simulations, diagrams, and annotations written in Russian.
The center is one of Southeast Asia's most state-of-the-art facilities.
An officer affirmed that the sailors and staff there all have an adequate grasp of Russian.
The sailors’ eagerness to learn the Russian language was confirmed after the Tuoi Tre contributor met Team 7, which was once trained in India.
On Friday evening, the members did not watch films or sing together.
The 40-year-old team leader and his juniors as young as 24 years old were totally engrossed in their Russian studies.
Trained in Russia, the Tuoi Tre contributor sought permission to join their learning session.
Her keen observations showed that even those who just took up the language a few months back and mostly learn by teaching themselves are surprisingly proficient in the language.
The Russian experts who the Tuoi Tre contributor briefly talked to earlier during the trip gave them profuse compliments on their diligence, brightness, and willingness to learn.
The brigade received two Kilo-class submarines 182-Hanoi and 183-Ho Chi Minh City over one year ago but the officers and sailors have been in full control of the vessels.
They do not need accompanying Russian experts during their trips that last several days under the sea.
Vietnam signed a contract to buy six Kilo-class subs from Russia during Prime Minister Nguyen Tan Dung’s visit to Moscow in 2009.
Officers and hands on the 184-Hai Phong Submarine also manoeuvered the ship with relative ease thanks to their adequate grasp of the Russian language.
Apart from taking classes in professional skills, the sailors spend 3.5 hours from 7:30 pm to 11:00 pm every day but they still can get up at 6:00 the next morning for a three-kilometer run.
The officers insist only Russian be used in many of their internal meetings.  
Submarine sailors and an officer are pictured during a drill. Photo:Tuoi Tre
No room for errors
Safety and teamwork are the utmost priority among submarine sailors.
“There’s no room whatsoever for errors, as they may cost lives,” the head of Submarine Brigade 189 stressed.
One of the stories which the Tuoi Tre contributor found most compelling was the sonar radar operators’ keen sense of hearing to detect all passing ships of various sizes.
During highly authentic emergency exit drills, whenever some problem arose in a chamber, instead of getting out, the sailors inside that chamber were required to lock themselves tight in and work on the problem in order not to affect other chambers.
The sailors and their special work thrive on their mutual understanding, trust, and willingness to sacrifice for their comrades.
More surprises in store
The Tuoi Tre contributor went from one surprise to another during her stay with Submarine Brigade 189.
One of them was how the male officers and sailors managed to keep their all-white uniforms speckless and crease-free, which is quite a challenge for many housewives [thems fighten words!].
The Tuoi Tre contributor also kept pondering over why all the naval soldiers boast such flawlessly white teeth.
According to Dau Van Hoang, captain of the 184-Hai Phong Submarine, the first priority for submarine sailors is having decay-free teeth.
“Inside the submarines, where oxygen is such a scarcity for several days on end, the entire crew members stay alive on a mixture of air, of which oxygen makes up a mere 29 percent or even a lower percentage,” he explained.
“The exhaled air is always recycled to be inhaled again. If one has decaying teeth, the air would be rendered unusable,” Hoang said with a beaming smile, showing off his immaculately white teeth.
In one of the intriguing stories the Tuoi Tre contributor was told during her trip, Lieutenant Vu Van Dung, of Team 7, was prepared to get married, with his marriage date fixed.
However, he was sent to India for a task right before the wedding.
The two families decided to proceed with the wedding anyway, and Dung’s bride and her family agreed to carry out the bridal ceremony through Skype, a chatting program.
On the wedding day, the bride, the two families, their relatives, and friends celebrated the big day in Vietnam, while the groom attended the ceremony and party through Skype.
[The Sun sinks slowly onto the tranquil Kilo] A submarine docks proudly at the Cam Ranh Military Port in Khanh Hoa Province. Photo: Tuoi Tre
Russian-made Kilo-class submarines, dubbed “black holes in the ocean” for its astonishing ability to vanish into the depth of the ocean, were built on a pilot basis during the mid-1990s.
Four electric-diesel Kilo-class subs have been handed over to Vietnam.
The fifth one, Khanh Hoa, left the Admiralty shipping yard in Russia on a trial run on April 1, 2015.
The sixth, Vung Tau, whose building began in May last year, is expected to be transferred to Vietnam next year.

April 20, 2015

Indians duped by Pakistani Rumour of Sale of 8 Submarines from China?

As Chinese President Xi Jinping visits Pakistan today and tomorrow an 8 submarines for Pakistan deal is supposed to be signed. I suspect no firm deal will be signed because expectations in the Indian and international press are based on a Pakistani rumour campaign.

Pakistan has been trying to extract free or reduced price submarines from China for years. Pakistan has used an information loop rumour strategy over the last few weeks to try to pressure China to sell. 

How can Pakistan, with a naval budget of around $750 million(?) per year afford to buy, crew and maintain the 8 for wildly different amounts:
- $250 million to $325 million each to 
- equivalent o$500 million to 625 million each?

The specific aim is to pressure Chinese President Xi Jinping to sign a deal when he visits Pakistan April 20 and 21, 2015. If Pakistan claims a deal has been made then it would need to prove it with details, including:
- numbers of subs sold?
- type of subs? (ie. old Ming or newer Yuan class submarines, not vague "Project" "S-26" of "S-30" designations)
- delivery or building schedule? (when is the first submarine and last to be delivered?)
- are the submarines used or new-build according to Pakistani specifications?


- March 9, 2011 The Hindu “Pak plans to acquire 6 submarines from China” Obviously didn’t happen.

- March 1, 2014  Times of India story  - quoting a Pakistani official proved groundless with no deal made "by end 2014." China didn't sign.

Pakistan times its latest rumour campaign in preparation for President Xi vist:

- March 31, 2015 Dawn article  "ISLAMABAD:  [Pakistani] Naval officials informed the Standing Committee on Defence Monday that the federal government has endorsed a summary to get eight submarines from China." -No Chinese promise.

- April 2, 2015  Discussion board insert - referring to speculative Dawn article No Chinese promise. 

- April 2, 2015 Reuters article  - - Pakistani Prime Minister Nawaz Sharif has approved a deal "years in the making" [but has China approved?] to buy eight submarines from China, a Pakistani government official said on Thursday, in what could be one of China's largest overseas weapons sales once it is signed. The [Pakistani] official...said the deal to buy the diesel-electric submarines would likely be signed by Chinese President Xi Jinping when he visits, "but that is still not final".
"...Asked about the submarines, Chinese Foreign Ministry spokeswoman Hua Chunying [only said] China and Pakistan were friendly neighbors and that the two sides had normal military exchanges. "I can tell you, relevant cooperation does not violate international convention and accords with China's three principles on military exports," she told a daily news briefing." No Chinese promise.


President Xi has now departed Pakistan and, in line, with my earlier prediction there has been no Chinese mention (that I've seen) of Chinese submarines for Pakistan http://tribune.com.pk/story/873354/chienese-president-xi-jinping-to-address-joint-session/ . The usual Pakistani speculation remains.

Pakistan’s has five medium sized submarines but needs newer submarines to counter India. Pakistan’s flotilla is:

- two Agosta 70s (PNS Hashmat and PNS Hurmat) completed in 1979-1980 – past the usual 30 year in water use-by date - hence probably semi or non-operational, and

- three Agosta 90Bs with completion dates (PNS Khalid (1999), Saad (2002) and Hamza (2006)) As they are AIP, Exocet capable/equipped and the last two built in Pakistan this is quite an achievement.

As Pakistan is more than $60 Billion in debt and has a naval budget of around just $750 million it may not even be able to crew or maintain 4 to 8 extra submarine even if China donated them.

Pakistan has been talking about converting Babur cruise missiles for submarine use but China already has small SLBMs like the JL-1  that might be more appropriate.  

Pakistan may be able to put nuclear warheads on its Exocets.

I think China considers Pakistan too unstable, and uneconomic to give it second strike submarine platforms. Pakistan is also a source of Islamic militancy but China has Islamic terrorism problems. They are not natural allies other than in their joint effort to partially surround India.


April 18, 2015

Australian Naval Shipbuilding 30-40% pricier. Submarines Unmentionable.

A Virginia SSN being completed in a massive Newport News shed. Will Australia ever build such submarines efficiently?
On April 16, 2015 Australia's Minister for Defence [Media Released] a RAND Corporation Report Australia’s Naval Shipbuilding Enterprise – preparing for the 21st centuryProbably the most significant finding is that “The cost of building naval ships in Australia is 30-40 per cent greater than United States benchmarks,…”. In contrast to South Korea's shipbuilding success Australia's shipbuilding industry has long been afflicted with the higly unionised British disease. Responsibility averse government and private sector management is another major failing.

Even with this defacto 40% tariff protection Australia cannot compete because ships and submarines  routinely completed 1 or 2 years late - often with subsequent modifications necessary. 

For Submarine Matters the absence of any discussion of Australia’s future submarine build in the Report compromises the whole report. It is akin to taking Future Frigates out of the equation.

The RAND Report, in part, found that:

·     "Australia could sustain a naval ship building industrial base by carefully managing a continuous ship building strategy in the longer–term, with a regular pace of delivering the new ships. But this would need to be premised on reform of the Australian naval ship building industry and significant improvement in productivity.

·       Australian naval ship builders can sustain an 18-24 month pace of large ship construction starts if Defence carefully manages its acquisition program and keeps the Future Frigates operational for 25 to 30 years [ie. needlessly shorter period than usual].

·       The gap between the completion of the Air Warfare Destroyer project and the start of the Future Frigate – Labor’s valley of death – cannot be overcome, but the impact could be lessened.

·       The cost of building naval ships in Australia is 30-40 per cent greater than United States benchmarks, and even greater against some other naval ship building nations. Australia is currently one the most expensive places to build naval vessels. This premium can be reduced by improved productivity through:

o  -  Establishing a consistent production and build demand.
o  -  Selecting a mature design at the start of the build and limiting the amount of changes once production begins.
o  -  The necessity of ensuring a well-integrated designer, builder and supplier team.
o  -  Matching the industrial base structure to demand.
o  -  Ensuring there is visionary leadership provided by company management.

The RAND report is a critical input into the Defence White Paper and the Naval Shipbuilding Plan. The Government will now carefully consider the report’s analysis and findings in preparation for the release of these documents later this year."


“But the report strikingly left the future submarine project out of its calculations, concentrating instead on surface warship such as new frigates and patrol boats.

When asked why, lead researcher John Birkler told reporters submarines had been "specifically excluded" from RAND's terms of reference by the Abbott government. "We were asked not to include submarines," he said.

Mr Birkler went on to indicate that RAND had been told by the government last year that Australia planned to build its submarines offshore.” His remarks, backed up by a table in the report that places the future submarine project in the "build offshore" column, is clearly at odds with the government's repeated insistence that it had at no point decided to have Japan build the new fleet of up to 12 submarines.

[In unconvincing contradiction] “A spokesman for Mr Andrews said that at "no stage were RAND Corporation informed by the government or the Department of Defence that an offshore submarine build was the only option being considered".” See WHOLE SMH ARTICLE


The Report's productivity improvement recommendations are US best practice. This is understandable given the US authorship. The recommendations, however, appear to be technologically and economically unsustainable for Australia. Australia cannot cover all the design and development functions unlike the output of Soryus at the MHI-KHI shipyards and unlike output of the Virginia class at Newport News and General Dynamics Electric Boat.