April 10, 2015

Pace of India's nuclear submarine program, Arihant, Chakra.

Perhaps a minimally doctored August 2014 photo of INS Arihant. It shares similarities with Russia's latest, minimally humped, Borei class SSBN and the preceding very humped, sail planed, Russian Delta SSBN.
Minimally humped, Borei class SSBN 
A very humped Delta II class SSBN with sail planes like Arihant.


On April 5, 2015 I was tasked by "lachit" to assess India's nuclear submarine state of play:

"India needs to get her nuclear subs SSBN & SSN & SSGN up running pronto. Can you guess which subs will ultimately take over the role of SSGN? I would surely like to know your personal opinion on the capabilities of Arihant sub. Thanks

On April 8, 2015 (and in the same thread) Biswajit Pattanaik augmented my tasking with the preamble:

@"lachit" my bet will be on S2/ARIHANT,S3 &S4 SSBNs that they will be converted into SSGNs. This will happen when in the future the better & the bigger SSBNs i.e. S5,S6 & S7 comes into service.

Hi Pete,
Just want to add something about Future Indian SSNs. According to me either Indian Navy could go with a Barracuda based SSN or even a Scorpene based SSN just like the Brazilians Sn-BR SSN. What's your take on this?"


To which I respond:

You entrust me with grave responsibilities :) My personal response, is:

I've followed INS Arihant's publically available information since it was launched in June 2009. At the launch ceremony (then) Prime Minister Singh thanked the Russians implicitly for their ongoing assistance on the submarine reactors on "S-1" and S-2.

S-1 is the half submarine reactor test rig at Kalpakkam (India's southeast coast, just south of Chennai)
S-2 is INS Arihant itself (undergoing trials - may never be operational).
S-3 is INS Aridhaman (under construction at the Shipbuilding Centre Visakhapatnam (India's east coast)) probable launch perhaps late 2015 or in 2016 - will be the defacto first of class SSBN initially with K-15s.
S-4 no name yet (under construction Shipbuilding Centre Vadodara prior to launch perhaps in 2017)

Arihant was/is only intended as a technology demonstrator (particularly for the reactor) a bit like the USS Nautilus rather than a serious first of class. Unlike the Nautilus there has been no list of Arihant's nuclear sub achievements eg. long submerged range or endurance. This makes me suspicious that Arihant has had major problems with its reactor functioning - the major new piece of technology. The need for security - away from prying Pak or Chinese craft - may be another reason for avoiding long semi-public sea voyages.

The delays in Arihant seem to have increased unrealistic expectations that it could be an operational submarine design.

The distinction between SSN's and new-build SSGN's (G for guided missile) is largely historical and decidedly Russian. The distinction mainly rested on the first SSN's being only horizontal torpedo tube armed and very much orientated to torpedos and mines with few or no missiles. 

Over the last 20 years SSN-SSGN distinctions have become clouded  as horizontally launched missiles have become a major component of an SSN's armament. An even more fundamental structural change has been Vertical Launch Systems for most new build SSNs (be they Akulas, Yasens, later Los Angeles and Virginia class). Therefore new build SSGN's have been merged into "SSN" or in the case of the Yasen "multi-purpose". I think India will be building "multi-purpose SSNs" in the direction of the Chakra class (Akula II) rather than separate SSN and SSGN designations. However, Arihant may evolve into the only SSGN and specialising in missile tests, rather than being an actual new build SSGN.

Advances in missiles' range mean that even SSN fired cruise missile have (or will have) the range to hit anywhere in Pakistan while land launched Agni IIIs (with a light warhead load) can hit anywhere in China. Agni III's will be supplemented by K-4 SLBMs in around a decade. 

It would be tidy for India to have a firm build schedule for nuclear subs S3 through S7 but I think India's build schedule is still under development and heavily dependent on Russian advice - in exchange for India paying excessive amounts for Russian arms (effectively subsidization). Also India has unique geography and needs that submarine types can be iteratively evolved around. India is not the US or Russia than can afford 10 new SSBNs and 20-40 new missile armed SSNs. Multi purpose Indian designs may become a substantial component.

The initial Indian SSNs, if they stay at the Arihant class' displacement of 6,000 tons (surfaced) will be underpowered unless they have an uprated reactor (maybe 130 MW). This may take some years to achieve. The reactor in the Chakra/Akula is an obvious item to study. As the study of reactor safety takes decades I suspect that Russian advisers are on hand towards the rear of the Chakra and Arihant.

An SSBN version of the Arihant appears to have the right sized reactor if the speed specifications are accurate.

Rather than Arihant and follow on subs being influenced by French nuclear submarines (like the Barracuda) I think Russia's Delta class and Borei subs are already a strong influence. India was, and I assume still is, extraordinarily committed to two Chakra/Akula IIs. India appeared to cross subsidise Russia nuclear sub building program in the long years Chakra/Akula was being built when Russia was crying out for defence money.

Much patience is needed tracking India's nuclear sub program. Unlike the 10+% of Russian and US GDP's that resulted in rapid nuclear sub program gains in the 1950s-60s India is only spending around 2.5% GDP on defence (according to Stockholm SIPRI stats). This is not a breakout amount for rapid increases in numbers or models. India's nuclear sub program also faces competition from the probably highest priority Agni IRBM-ICBM program and from India's conventional military priorities.

The launch of INS Aridhaman, perhaps later this year, will be the next major step.

Please connect with India's Rising Nuclear and Conventional Submarine Force, May 21, 2015 http://gentleseas.blogspot.com.au/2015/05/indias-rising-nuclear-and-conventional.html .



lachit said...

well sir when i saw the post "Pace of India's nuclear submarine program, Arihant, Chakra"
i was very much touched.u certainly care about ur readers.

the delay in ARIHANTS deep sea trials may be due to the fact that the indians are waiting for the arrival of DSRV(deep sea rescue vessels)from britain.

and ur right about ur conclusions that the arihant will serve as a technology demonstrator.And maybe if everything works out all right it will be used as a testbed for validating SLBM technologies and miscellaneous technologies like underwater communications,VLF communications,command and control protocols for missile launch,SOPs for deep sea patrol etc

as for the bigger SSBNs s5,s6,s7
i have a photo from a drdo presentation where the indian SSBN looks almost like the delta iv.i will not be surprised if SEVMASH is providing consultancy work on the design and fabrication of these SSBNs but the finished product might end up different from the deltas.

and now that u mention it, the arihant sure looks like a cross between delta and borei.albit a clever and seamless integration of the bow,sail and hump if i may say so.

the last deal for 42 su 30mki was way over priced guess now we know where the extra money went. hehehe

also i think u have a point in saying that india might go for hybrid SSGN and SSN aka multipurpose SSN.

as for the SSNs i have a feeling the indians will take the help of france.
modi yesterday made a deal for 36 off the shelve rafales in a G to G deal.
and india will use the G to G route for future rafale acqusitions as a bait to acquire french SSN design for the indian SSNs.it makes sense too since after building the scorpenes india already has the infastructure in place to build a nuclear super-scorpene or barracuda type SSN.

and again thanks a lot.
u just became my 2nd best australian after Nicole Kidman (aussie or no aussie, nobody beats her)hehehe.

Biswajit Pattanaik said...

Hi Pete,
Nice work Mr.Pete your assessment regarding India's nuclear submarine program provides a nice way foward.
Want to add some more (useful ;-) ) info regarding this;DCNS has been regularing showing Barracuda N-Sub at India's DefExpo (something is cooking behind those door for surely).
Plus you point that " I think India will be
building "multi-purpose SSNs" in the direction of the
Chakra class (Akula II) rather than separate SSN and
SSGN designations. However, Arihant may evolve
into the only SSGN and specialising in missile tests,
rather than being an actual new build SSGN" can't be ignored as India need to have some sort of standardization across her nuclear platforms.
You could be quite right when u say that S2/Arihant could be used as a test platform for future Nuclear underwater weapon platform.
In past there were some report emanting from IN navy that they prefer single hull SSN (which i believe Akulas' r not thet r twin hulled).
"The initial Indian SSNs, if they stay at the Arihant
class' displacement of 6,000 tons (surfaced) will be
underpowered unless they have an uprated reactor
(maybe 130 MW). This may take some years to
achieve. The reactor in the Chakra/Akula is an
obvious item to study."
Well Mr.Pete you are quite an Intelligent person to say d least ;-) :-).
Indeed there is some work being done toward this requirement as well.
It was in 2010 that Admiral (Ret’d) Arun Prakash
went public by stating that the IN has asked the DAE to
develop a 190mW PWR first for the projected IAC-2, &
use this very same design for the planned S-5, S-6 &
S-7 SSBNs.
Its very interesting bcoz as you had said " The reactor in the Chakra/Akula is an
obvious item to study" an obvious choice would be 190 MW OK-650B/OK-650M PWR.
Plus. The PWR for the S-2/Arihant uses only 44%
enriched uranium (LEU) & will therefore not be useful
at all for SSNs. Since the IN’s SSN will be single-hulled( can't be sure about it,but it could well be turned out as well)
& much smaller in size, the reqmt is for a smaller PWR
using more than 60% enriched uranium, i.e. HEU. Laws
of physics state that the higher the level of enrichment
of the HEU, the smaller the reqd size of the PWR.
Once again nice work done Mr.Pete.
(sshhh......this blog is generating so much info on sub that Chinese will be eavesdropping on this blog plus the Japs,swedes,Ger & P5, maybe Aus Gov. as well)

Biswajit Pattanaik said...

Well,well Mr.Lachit looks like I also have the photo of that SSBN from DRDO-NPOL presentation, named something like SSSI-12 or SSBN S-12 or SSBN S-5 (maybe 12 could indicate 12,000tonnes or 12 SLBMs carring capability not sure what it is)
And indeed it looks like a DELTA IV SSBN to me.
And thank goodness atlast GoI is taking right approach towards procurement for Rafale Jets.

lachit said...

i tried to collect additional info.hope u find it informative.

Indias tryst for nuclear submarine began when US sent its Enterprise aircraft carrier to support Pakistan during the 1971 Bangladesh Liberation War,then Moscow sent a nuclear submarine to the Bay of Bengal in support of india. The PM Mrs Indira Gandhi, realised the importance of nuclear submarines and decided to build this capability indigenously.

The Half Submarine

US and France trained atomic scientist Dr Anil K Anand studied zircaloy joints and tubes and calandria ends in France’s Pressure Water Reactors (PWR) at the Centre Energy Atomique at Scalay near Paris in Section des Advances, for the French EL-4 PWR reactor at Brennilis and learnt the techniques that helped him at BARC.
eventually the BARC team under Dr Anand designed and built the half submarine with a miniature reactor (S-1) for training at the Indira Gandhi Centre for Atomic Research (IGCAR) at Kalpakkam. This went critical on November 11, 2003 and operational on September 22, 2006. Its replica is the Arihant’s 80(85??) MW pressured Uranium, U-235 light water reactor.

i believe this is the S 1

India's Arihant has an 85 MW PWR using 40% enriched uranium driving one or two 35 MW steam turbines. It has 13 fuel assemblies each with 348 fuel rods, and was built indigenously with some russian input.

i remember having read that the russian help came in the form of rather limited blue prints of the reactors of icebreaker Lenin.

(this was done to circumvent russian obligation to NPT, the chinese had adopted a similiar Modus operandi, they had access to the West German reactor used on the Otto Hahn and the Soviet reactor used on the Lenin like the indians)

the Lenin initially had three 90 MWt OK-150 reactors which used 5% enriched fuel. In 1970 they were replaced by two 171 MWt OK-900 reactors with 45-75% enriched fuel providing steam for turbines which generated electricity to deliver 34 MW at the propellers.
my guess is that the indians got designs inputs for the OK-900 reactors and they scaled it down to produce around 85 MW.

In a nuclear-powered vessel, an onboard reactor produces steam that is used to generate electricity and power the ship's propulsion system. Since the reactor must be small enough to fit in the confined space of a ship at sea, most naval reactors have relied on highly enriched uranium (HEU) for their fuel, which can generate more energy by volume than low-enriched uranium as a result of the greater density of fissile uranium-235 present in HEU.
Four navies are known to utilize HEU to fuel their nuclear-powered submarines and surface ships: those of the United States(either 97% uranium-235 produced specifically for naval reactors, or 93% uranium-235 extracted from surplus nuclear weapons),the United Kingdom(UK uses a similar enrichment level like that of US),Russia and Indi(approximately 40% uranium-235). Though some of France's earlier generation submarines utilized HEU, its newer submarines and the aircraft carrier Charles de Gaulle utilize fuel enriched to less than 10 percent uranium-235.China's submarines are believed to use approximately five-percent enriched LEU.

lachit said...

continuing from the above.....

however it remains to be seen whether india decides to use highly enriched uranium-235(>90%) to increase the lifespan of its reactor core thus allowing the submarine to operate at long intervals—perhaps even over the lifetime of the vessel—without the need for refueling.
as of now the present reactor core of arihant (using 40% enriched uranium) will have to be changed once every 10 years, and this is quite an expensive proposition.

india did face problems in the design of certain safety features.one of them worth mentioning is the control rod insertion and withdrawal mechanism.

(Rod Worth Minimizer RWM is an engineered safeguard system which prevents selection of control rod patterns having individual rods with a high reactivity worth within the core and an uneconomical use of reactor fuel. RWM accomplishes this by forcing adherence to an established control rod selection, withdrawal and insertion pattern during reactor operation.)

however its sale to india was denied by US.

The control rod technology for use with the rod worth minimizer has long since been developed by India. The reactor controlled by the CRDM--Controlled Rod Drive Mechanism, has got neutrons seperated from the fissionable material by cadmium rods, which are removed when the reactor is to be started, and thus the reactor or the heart of the submarine begins,thereby beginning the electricity, and all other operations of the submarine.

also HY-80 steel was chosen as the material of choice for the construction of the submarine pressure hull by india.however considerable problems were encountered during the welding and construction process.The welding problems were traced to the presence of nonmetallic inclusions, particularly sulfide stringers. In addition hydrogen-induced cracking was a continual problem. A detailed study was performed to solve these problems. Alternative steels were studied as replacement for HY-80, but in the end it remained the material of choice. The problems encountered with this steel were responsible in large amount for the large cost overrun.

Though in late December 1995 it was reported that DRDO had made considerable progress in the fabrication of the pre-test capsule (PTC) which was fabricated in 1994 at Hazira in Gujarat. From there it was transported to Kalpakkam. The PTC fabricated into the final shell is reported to be made of titanium steel and has a hull diameter of 10 meters.The use of a titanium steel hull enables the submarine to dive to deeper depths.

"The starboard side consists of two rectangular vents that draw in water when the submarine submerges into sea."
this qoute is from http://www.naval-technology.com/projects/arihant-class/

@peter in the first photo of arihant posted in this thread u can see 2 rectangular vents which have a series of circular holes one underneath the sail and another farther away from it,if the naval-technology.com are referring to it then they might have made a mistake because it could be the launchers for the anti torpedo decoys either the C-303/S anti torpedo countermeasure system or the RAFAEL SHADE torpedo defense suite for submarines

video of arihant as it navigates the harbour


Peter Coates said...

Hi lachit and Biswajit Pattanaik

Thankyou for all your comments and information.

It will take me time to digest it all.

Using it:
- I will respond on this thread in more detail tomorrow
- amend the current article of April 10, 2015, and
- write new articles.

Two things:

If Aus, US or Indian security bodies see any information as going too far beyond the public domain they can contact me using my email. We should be ever mindful that Pak and China-Hong Kong read the blog. I don't want to cause authorities to be concerned - also balancing with media freedoms.

Thankyou for the corroborating links (Time of India, Youtube etc). The more public record references the merrier - particularly as the launch of INS Aridhaman gets closer.

Kind Regards


Peter Coates said...

Hi lachit

Yes I care about my readers especially readers so knowledgeable. Thankyou for all the information.

The deep sea rescue vessels (DSRV) does seem plausible as one of the reasons for delay in Arihant testing.

Agree Arihant can be used for many other technology trials in addition to reactor functioning and missiles.

It occurred to me that Arihant's sale-fin-conning tower looks also like China's 094 Jin Class SSBN http://en.wikipedia.org/wiki/Type_094_submarine. INS Aridhaman and subsequent SSBNs may well look like the 094s. With Russia and China using what externally looks like a (Delta/094) pattern this must give India greater confidence that India is walking a sound technology path.

Extra Indian money to buy French nuclear sub technology and advice may have also come for several years through India's purchase of the six Project-75 Scorpenes as well as a future Rafale buy (if the Rafale buy actually happens).

I'm unable to find direct evidence of French NUCLEAR sub assistance to India however:

- The latest French-Indian nuclear agreements signed 2 days ago - Agreement 1 and 2 at http://ibnlive.in.com/news/list-of-agreements-signed-between-india-and-france/539126-3.html - involves French nuclear company Areva conducting extensive reactor building in India. Significantly Areva is intimately involved in French sub reactor design - eg. the Barracuda's reactor. http://en.wikipedia.org/wiki/Areva#Other_activities

For a 6,000 ton (surfaced) SSN derivative of the Arihant the Barracuda's Areva K15 reactor appears appopriate. It is rated at 150 MW (10 year refuel).

Russia's "Chakra/Akula" reactor (the OK-650B/OK-650M) rated 190 MW (http://en.wikipedia.org/wiki/Akula-class_submarine) is designed for the much larger 8,000 ton (surfaced) Akula. This makes the Russian reactor too heavy and powerful for the Arihant and likely derivatives.

The French track record also provides indicators that French assitance could occur for Indian nuclear subs:

1. France assisting Brazil to build a nuclear sub (SN-BR) http://gentleseas.blogspot.com.au/2015/03/brazil-new-submarine-prosub-program.html

2. possible joint French-Brazilian
development of the 2131-R PW submarine reactor,

3. that France (unlike other Western countries) did not condemn India over India's 1998 nuclear tests.

India may well use the advance on missile only VLS. That advance being Vertical Multi-Purpose Lock (VMPL) - already slated for Arihant's weapons evolution and a sound muli-purpose submarine solution. see diagram http://gentleseas.blogspot.com.au/2014/05/indias-march-2014-k-4-slbm-pontoon-test.html .

Thanks regarding Nicole Kidman - she is definitely richer and prettier :)

More to follow on your and Biswajit Pattanaik's comments.



Peter Coates said...

Hi Biswajit Pattanaik

Thanks also for all the information. Drawing from your comments I've come up with the following scenarios.

I think India can build an SSGN or multi-purpose sub using increasingly advanced Vertical Multi-Purpose Lock (VMPL) technology - already used for the 4 US Ohio class SSGNs. VMPLs seem already intended for Arihant according to Wikipedia with 12 K-15s (in theory being replaced by 4 K-4 missiles). http://en.wikipedia.org/wiki/Arihant-class_submarine#Description

On the Arihant the length of the K-4 (12m) may prevent mobile tests - instead just stationary tests.

If INS Aridhaman (as an SSBM) has the hump indicating a draft around 13m it should then be able to accomodate 12m K4 missiles. If http://en.wikipedia.org/wiki/INS_Aridhaman is correct it will carry eight K4 (more than the Arihant very theoretical four).

With the extra draft and length (more than Arihant) required for Aridhaman I would estimate Aridhaman would weigh around 8,000-9,000 tons (surfaced).

This would clearly require a more powerful reactor for Aridhaman than Arihant's 83 MW. One of 130-150 MW for around 23 knot submerged would probably be ideal. The Chakra/Akula reactor of 190 MW may be helpful but too powerful for a SSBN (though of course right for a SSN/SSGN (like Chakra/Akula)).

I'd venture the chances of French assistance - handing over its 150 MW Barracuda reactor (see my comment to lachit above) increases the more weapons India buys from France:

- completing the 6 Project-75 Scorpene build
- buying the 36 Rafales http://zeenews.india.com/news/india/pm-modi-in-paris-india-to-buy-36-rafale-jets-france-to-invest-2-billion-euros_1576832.html AND
- significantly, buying 6 Project 75-I advanced AIP Scorpenes

Concerns that France is proliferating nuclear military technology to India can be countered:
- noting the US-UK deal of the 1950s, and
- that India already has a nuclear sub, submarine reactor and, of course, nuclear weapons.

India always seeks diversity in its arms purchasing as part of its non-aligned status. It has relied to Russia for much of its nuclear propulsion but France can provide another, possibly competing, source.

France's 150 MW reactor could drive a 6,000 ton (surfaced) SSN/SSGN already evolving from the Arihant and

Drive a 8,000 to perhaps 10,000 ton SSBN.

It will be interesting if a MW figure for Aridhaman's reactor is eventually published? It will depend on how complete a design Arihaman is.



Anonymous said...

I believe the French K15 only powers their SSBN so I highly doubt France will be sharing SSBN acoustic signature to others. French SSN including the Barracuda os powered by smaller reactors 50MW.
One tends to build upon one's nuclear reactor operating experiences, so in my view the most likely upgrade path for India is a localized version of the OK-650.

Peter Coates said...

Hi Anonymous

Thanks for your input. Most of the references I've looked at either mention "modified" "developed from" and "based on" the K15 or Barracuda actually uses the K15.

For example http://www.naval-technology.com/projects/barracuda/ indicates "The power plant will be based on technologies developed for the 150MW K15 pressure water reactor installed in the Triomphant Class submarine and the Charles de Gaulle aircraft carrier."

On "50MW" perhaps the K15 consists of 3 x 50MW units?

We may all be right if "K15" is a generic expression for reactor "K" rated at "15" = 150 MW - with much leeway for the technical specifics of the reactor.

You may well be right "in my view the most likely upgrade path for India is a localized version of the OK-650." India has examined the Russian 190 MW OK-650B/OK-650M PWR in detail because it is using it in the Chakra/Akula.

As the French-Indian reactor relationship deepens then India might develop its own version of the "K15" or similar.



Peter Coates said...

Hi Lachit

Thankyou for your information and links of April 12.

I tend to think low claims like 5% U-235 are hard to believe being more for public relations and international relations. 5% being more "legal" as it is below the 20% HEU proliferation no-no.

Politicians, and lawyers can accept "5%" but navies and engineers will point out that 5% would make for a very inefficient reactor in:
- power to size or weight ratio, and
- produce submarines that are forever in dock being refueled.

I suspect 5%-20% might be what the U was at an early enrichment stage only to be further enriched by countries, like Brazil, to a more efficient reactor level like 60%.

"Controlled Rod Drive Mechanism" sounds quite possible.

HY-80 for Arihant's hull looks plausable. Although I suspect India will go for higher HYs with later subs for the tactical advantages of deeper diving.

India using titanium would have the advantage of Russian experience and perhaps low Russian prices if bought from Russia.

Thanks for the info "anti torpedo decoys either the C-303/S anti torpedo countermeasure system or the RAFAEL SHADE torpedo defense suite for submarines"

Here are good descriptions of the:
- German developed 303S http://www.aiad.it/aiad_res/cms/documents/WASSC303S.pdf and
- Israeli developed Rafael SHADE http://www.rafael.co.il/Marketing/291-1566-en/Marketing.aspx .

What with these decoys as well as UUV, UAV, sub launched AA missiles, Seal Delivery Vehicles and comms buoys, submarines have too many choices!



lachit said...

thanks for the reply and links to the torpedo decoy/countermeasure systems

Biswajit Pattanaik said...

Hi Pete,
Thanx for all the replies & info u have provided.
Keep up the fabulous work Mr.Pete;keep going.

Peter Coates said...

Thanks Biswajit

I sure will and appreciate your comments.

Feel free to comment on the latest South Korea article. Korea seems to be putting the necessary elements together to build a submarine reactor if need be.