Indian nuclear submarines

Aniruddha Mulay

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When will they lay S5 class?
Also why S4 and S4* haven't been named yet?
I guess the construction of S5 class SSBN will start sometime in 2023 once S4* is moved to a drydock.
Since much of the details of the ATV project remain highly classified, we may never know the names of the 2 subs until they are in active service with the Indian Navy.
 

Aniruddha Mulay

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Guys , if Vizag SBC is occupied with SSN, then when will they build S-5 class boats?
SBC currently can handle construction of 2 nuke boats simultaneously.
A few years back, Sandeep Unnithan in his article had stated SBC was going to be upgrades to build 4 nuke boats simultaneously.
So 2 S5 class SSBN + 2 P75A SSN is entirely plausible
 

FactsPlease

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Gessler

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Surely France (DCNS) now is more than eager to assure Brazil SN-BR project will succeed.

Some old posts (admit I'm too lazy except some keyboard searching)
Brazil nuclear submarine postpone to 2025
Brzail PROSUB project
I have little faith in the Brazilian program succeeding. And all that for 1 sub?

Doesn't seem like a practical program for the long run, at least the Aussies have a plan in place for 8 boats.

Canada (it really need SSN or least nuclear-powered patrol for that huge arctic area)?
If Canada needed N-subs, it would have been in the Cold War. In today's time or in foreseeable future RCN would only need N-subs if Russian Navy becomes hugely resurgent (beyond what can be managed by USN+RN), with their economy down the drain doesn't seem likely.

Australia is only having to go for N-subs now because of the ever-increasing Chinese threat in the region.
 

pipebomb

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I have a few questions/observation

- Is 83mw power of barc naval reactor inadequate for ssn or the way it delivers power that makes it inadequate.(i only ask this because rubis ssn's reactor has even smaller capacity)

- Is the 83mw actual power generated by ins Arihant or is it reactor's theoretical capacity

- If barc naval reactor is adequate for ssn then can we say that IN in not in a hurry(for whatever reasons) to induct ssns that its willing to wait for 150-180 mw reactor.

- Is barc naval reactor a heu design. If so, does that mean it didn't need to be refueled for its whole operational life. If it does need to be refueled than what's the point of heu.
 

Haldilal

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I have a few questions/observation

- Is 83mw power of barc naval reactor inadequate for ssn or the way it delivers power that makes it inadequate.(i only ask this because rubis ssn's reactor has even smaller capacity)

- Is the 83mw actual power generated by ins Arihant or is it reactor's theoretical capacity

- If barc naval reactor is adequate for ssn then can we say that IN in not in a hurry(for whatever reasons) to induct ssns that its willing to wait for 150-180 mw reactor.

- Is barc naval reactor a heu design. If so, does that mean it didn't need to be refueled for its whole operational life. If it does need to be refueled than what's the point of heu.
Ya'll Nibbiars

1 . The INS Aright has a more powerful reactor. Don't believe the same reactor power as the INS Arihant.

2 . A 190 MW reactor is in development when will be in service don't knew.
 

Gessler

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I have a few questions/observation

- Is 83mw power of barc naval reactor inadequate for ssn or the way it delivers power that makes it inadequate.(i only ask this because rubis ssn's reactor has even smaller capacity)
Broadly speaking, yes. But it depends on a lot of other things.

How big is your SSN? How much power does it need to move? To use the example you gave (Rubis), its the smallest nuclear submarine in world - only about 2,500 tons, just a tad bigger than Scorpene and actually smaller/lighter than double-hulled Kilo.

- Is the 83mw actual power generated by ins Arihant or is it reactor's theoretical capacity
The Arihant's CLWR-B1 PWR generates 83 mwt (megawatt thermal) - and approx 16-20 mwe (megawatt electric) of usable power (drawing a blank on the exact figure).

These figures (mwt or mwe) are the rated safe operating limits. But a sub doesn't always operate at that level - the power output is slowly increased/decreased according to mission needs (high speed transit/evasion or just providing for hotel load if just parked on sea floor).

All reactors are theoretically capable of going above the safe limit in emergencies, but unlikely to sustain that for long.

- If barc naval reactor is adequate for ssn then can we say that IN in not in a hurry(for whatever reasons) to induct ssns that its willing to wait for 150-180 mw reactor.
There is no official information on what reactor will find use on either SSN or S-5.

There is, however, a rumour that an 'improved' version of CLWR-B1 with higher enrichment & slightly bumped up power output (about ~100mwt) could find application on SSN.

- Is barc naval reactor a heu design. If so, does that mean it didn't need to be refueled for its whole operational life. If it does need to be refueled than what's the point of heu.
Yes all our PWRs are HEU-based. But HEU is not a blanket statement - there are various levels of HEU. Our models are believed to use about 40% enriched uranium - which means at least 1 refueling will be necessary over the sub's service life.

US, UK & Russian reactors use above 90-95% enrichment - they don't need to be refueled at all.

French use LEU which of course requires to refuel at least twice in lifetime, which makes them the most inefficient & expensive to maintain. But they have the benefit of requiring less upfront cost thanks to avoiding of fuel enrichment, plus lot more commonality with civilian reactor designs. AFAIK China also uses LEU...or relatively low-grade HEU (not up to a 100% on that, know very little about chinese sub programs).
 

Gessler

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Broadly speaking, yes. But it depends on a lot of other things.

How big is your SSN? How much power does it need to move? To use the example you gave (Rubis), its the smallest nuclear submarine in world - only about 2,500 tons, just a tad bigger than Scorpene and actually smaller/lighter than double-hulled Kilo.



The Arihant's CLWR-B1 PWR generates 83 mwt (megawatt thermal) - and approx 16-20 mwe (megawatt electric) of usable power (drawing a blank on the exact figure).

These figures (mwt or mwe) are the rated safe operating limits. But a sub doesn't always operate at that level - the power output is slowly increased/decreased according to mission needs (high speed transit/evasion or just providing for hotel load if just parked on sea floor).

All reactors are theoretically capable of going above the safe limit in emergencies, but unlikely to sustain that for long.



There is no official information on what reactor will find use on either SSN or S-5.

There is, however, a rumour that an 'improved' version of CLWR-B1 with higher enrichment & slightly bumped up power output (about ~100mwt) could find application on SSN.



Yes all our PWRs are HEU-based. But HEU is not a blanket statement - there are various levels of HEU. Our models are believed to use about 40% enriched uranium - which means at least 1 refueling will be necessary over the sub's service life.

US, UK & Russian reactors use above 90-95% enrichment - they don't need to be refueled at all.

French use LEU which of course requires to refuel at least twice in lifetime, which makes them the most inefficient & expensive to maintain. But they have the benefit of requiring less upfront cost thanks to avoiding of fuel enrichment, plus lot more commonality with civilian reactor designs. AFAIK China also uses LEU...or relatively low-grade HEU (not up to a 100% on that, know very little about chinese sub programs).
Yeah, Chinese PWRs are LEU

Too bad for them :cool3:
 

Aniruddha Mulay

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Broadly speaking, yes. But it depends on a lot of other things.

How big is your SSN? How much power does it need to move? To use the example you gave (Rubis), its the smallest nuclear submarine in world - only about 2,500 tons, just a tad bigger than Scorpene and actually smaller/lighter than double-hulled Kilo.



The Arihant's CLWR-B1 PWR generates 83 mwt (megawatt thermal) - and approx 16-20 mwe (megawatt electric) of usable power (drawing a blank on the exact figure).

These figures (mwt or mwe) are the rated safe operating limits. But a sub doesn't always operate at that level - the power output is slowly increased/decreased according to mission needs (high speed transit/evasion or just providing for hotel load if just parked on sea floor).

All reactors are theoretically capable of going above the safe limit in emergencies, but unlikely to sustain that for long.



There is no official information on what reactor will find use on either SSN or S-5.

There is, however, a rumour that an 'improved' version of CLWR-B1 with higher enrichment & slightly bumped up power output (about ~100mwt) could find application on SSN.



Yes all our PWRs are HEU-based. But HEU is not a blanket statement - there are various levels of HEU. Our models are believed to use about 40% enriched uranium - which means at least 1 refueling will be necessary over the sub's service life.

US, UK & Russian reactors use above 90-95% enrichment - they don't need to be refueled at all.

French use LEU which of course requires to refuel at least twice in lifetime, which makes them the most inefficient & expensive to maintain. But they have the benefit of requiring less upfront cost thanks to avoiding of fuel enrichment, plus lot more commonality with civilian reactor designs. AFAIK China also uses LEU...or relatively low-grade HEU (not up to a 100% on that, know very little about chinese sub programs).
Members of the other defense forum, Strategic Front say that development of CLWR-B2, a 190MW reactor is complete as per documents released by BARC and that they are currently underway with the fabrication process
 

pipebomb

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Broadly speaking, yes. But it depends on a lot of other things.

How big is your SSN? How much power does it need to move? To use the example you gave (Rubis), its the smallest nuclear submarine in world - only about 2,500 tons, just a tad bigger than Scorpene and actually smaller/lighter than double-hulled Kilo.



The Arihant's CLWR-B1 PWR generates 83 mwt (megawatt thermal) - and approx 16-20 mwe (megawatt electric) of usable power (drawing a blank on the exact figure).

These figures (mwt or mwe) are the rated safe operating limits. But a sub doesn't always operate at that level - the power output is slowly increased/decreased according to mission needs (high speed transit/evasion or just providing for hotel load if just parked on sea floor).

All reactors are theoretically capable of going above the safe limit in emergencies, but unlikely to sustain that for long.



There is no official information on what reactor will find use on either SSN or S-5.

There is, however, a rumour that an 'improved' version of CLWR-B1 with higher enrichment & slightly bumped up power output (about ~100mwt) could find application on SSN.



Yes all our PWRs are HEU-based. But HEU is not a blanket statement - there are various levels of HEU. Our models are believed to use about 40% enriched uranium - which means at least 1 refueling will be necessary over the sub's service life.

US, UK & Russian reactors use above 90-95% enrichment - they don't need to be refueled at all.

French use LEU which of course requires to refuel at least twice in lifetime, which makes them the most inefficient & expensive to maintain. But they have the benefit of requiring less upfront cost thanks to avoiding of fuel enrichment, plus lot more commonality with civilian reactor designs. AFAIK China also uses LEU...or relatively low-grade HEU (not up to a 100% on that, know very little about chinese sub programs).
Thanks for your response, it was very enlightening. I completely overlooked thermal power vs electrical power. Also i mistakenly consider heu close to weapons grade. I agree with you that we should continue with heu, maybe our next class of naval reactors doesn't need to be refueled during life time. LEU seems like a dead end.

Do you think double hull design is expensive or does it worth the hassle ?

Also why do you think our previous naval chief was showing interest in French leu ?
 
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werewolf

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Thanks for your response, it was very enlightening. I completely overlooked thermal power vs electrical power. Also i mistakenly consider heu close to weapons grade. I agree with you that we should continue with heu, maybe our next class of naval reactors doesn't need to be refueled during life time. LEU seems like a dead end.

Do you think double hull design is expensive or does it worth the hassle ?

Also why do you think our previous naval chief was showing interest in French leu ?

Chack this out.Might be helpful
 

Gessler

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Members of the other defense forum, Strategic Front say that development of CLWR-B2, a 190MW reactor is complete as per documents released by BARC and that they are currently underway with the fabrication process
I'm aware (am a mod on that forum), but personally I choose to limit my analysis to known facts, and where necessary, make the shortest possible leap into hypothesis. It has served me well in order to stay planted, if I'm right, I'm comfortable in staying in the 'facts' I already knew, if I'm wrong, then it comes as a pleasant surprise.

Something I've honed over last nearly ~10 years of being on forums & thirsting over every could be/should be thesis.

:yo:

Do you think double hull design is expensive or does it worth the hassle ?
Just like for previous answer - it depends on lot of other factors. A Russian or Chinese double-hulled can be much cheaper than a Western single-hulled boat.

As of is it worth it - way I look at it, if you can get away with single hull, best to do so. The concept of double hull is usually a way to 'tide over' design inefficiencies on the inner hull which make it not very hydrodynamic (i.e. compartments of varying diameter necessitated by inability to miniaturize certain components etc.), by just encasing them all in a hydrodynamic outer hull.

If you can make the inner hull strong enough & hydrodynamic enough, then a outer hull is quite frankly not needed. Look at the French Triomphant-class SSBN for example - look how seamlessly the missile compartment is integrated, you cannot even see a HINT of a 'hump'. If not for the size & scale, no one could tell this was even an SSBN and not SSN.



Now that's great submarine design.

But thanks largely to extensive Russian involvement in India's N-sub program, all of our nuclear boats (Arihant, S-5 & SSN) are going to be double-hulled. I'm not worried though...considering our main threat vector (China) is no better in that regard. They also rely entirely on double-hulled N-boats.

Also why do you think our previous naval chief was showing interest in French leu ?
He was showing interest in Barracuda-class, which incorporates a lot more than just the reactor. Namely, advanced sonars, pumpjet propulsion, optronic masts, etc.

Whereas cooperation with regard to reactor techs (in submarine context) goes beyond LEU/HEU debate - namely about how to quieten/isolate the reactor operation (which has to run non-stop). That is likely to have been the area of cooperation if any.

There is absolutely no indication IN has any plans for LEU at this stage, it would make no sense.
 

pipebomb

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Again sir extremely grateful for replying & your interest, this has been very informative
But thanks largely to extensive Russian involvement in India's N-sub program, all of our nuclear boats (Arihant, S-5 & SSN) are going to be double-hulled.
Why do you think india wants to persist with double hull in future submarines, i ask this because one of the two submarine types built in India, i.e. scorpene, is single hull design.( i am not sure about 209 weather its a single hull or not)
 

Gessler

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Again sir extremely grateful for replying & your interest, this has been very informative
You're welcome - no need for 'Sir', I'm a 25 yr old dude. :tongue:

Why do you think india wants to persist with double hull in future submarines, i ask this because one of the two submarine types built in India, i.e. scorpene, is single hull design.( i am not sure about 209 weather its a single hull or not)
209 is also single-hulled.

The only 'double-hulled' Western sub in recent times has to be that new Type-212CD that's under development. But the reason for its design is different (active sonar stealth with angular surfaces, while using same U212 inner cylindrical pressure hull which is more optimum for countering pressure).

As of why we will stick with double-hulled, that's the design language we've been taught and its going to cost a lot of money & lot of time to change that now. In the grand scheme of things, I guess we must have weighed the pros & cons and decided changing to single-hull is not worth it - at least not at this point.

For a post-2040 design (which we will inevitably build, the P75A/P76 & S5 won't be the last N-subs we build) we might or might not decide to switch to single-hull.

The designs of diesel subs are entirely different whereas our N-subs were specifically created with Russian help, and even Arihant is about 3-4 times larger than Scorpene/U209.
 

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