Indian Nuclear Attack Submarine (Project 77) - Updates & Discussions

[Gautam]

I thought the CLWR-B2 was still sometime away from being ready. But almost all publications are saying the reactor will be 150/190 MWth. I guess they won't make a land-based reactor this time.

With all this talk of the SSN being Akula based; I can't help but think that an Arihant (S4) based attack sub would be the best option for us:

Our cruise missiles (Brahmos & Nirbhay) are smaller in diameter than the K-15. So those launch tubes on the Arihant class should be able to house at least 4 missiles per silo. The hump behind the sail will also disappear as the cruise missiles are shorter than the beam of the submarine (8.5 m vs. 11m).

8 launch tubes & 4 missiles per tube. 32 missiles in VLS. 6 torpedo tubes with 30 round magazine capacity. This adds up to a total of 62 torpedoes & missiles. The Virginia class Block V is said to carry a total of 65 torpedoes & missiles. The Navy is probably using the Virginia Block V & SSN-AUKUS as the benchmark for their SSN.

Some 5 years ago the Navy was building a prototype pumpjet propulsor.

https://twitter.com/x/status/1320175768438190080

The major challenge in this project was that Indian industry had never built a 35MWe PMSM motor. BHEL was picked to develop the motor, if I remember correctly. Looking at the configuration of the pumpjet, it is clear that the Navy will be going for a nuclear electric propulsion setup.

So, this SSN will be a ~10,000-ton submarine propelled by a 190 MWth PWR powering a 35 MWe PMSM motor based pumpjet. The Virginia class Block V is a 10,200-ton submarine propelled by a 210 MWth PWR powering a 30 MWe motor based pumpjet.

Size wise the Arihant (S4) & the Virginia Block V compare as follows:
Length: 130 m (S4) vs 140 m (Block V)
Beam: 11 m (S4) vs 10 m (Block V)
Displacement: 7000 ton surfaced (S4) vs 10,200 tons submerged (Block V)

It would be much better to use the S4 as base design, replace the B1 reactor with the B2, get the new pumpjet, modify the hull shape as needed etc., then to go for Russian or French hull design where we have little to no control over the IP & know how/why.

 

[RISING SUN]

At the end of the Cold War, the Russians scrapped several dozen N-subs with US funding (nuclear radiation hazard). However, they have since rebuilt their submarine arm into a world-class force.

Even at the cost of large surface ships (no replacement for Kirov/Moskva class in sight), their N-sub production lines continue to hum. They are already planning a 5G SSN design called Husky.

H I Sutton - Covert Shores

Unlikely they will share cutting-edge tech with anybody, including India. These are their crown jewels.

Rumours say that the IN wanted to lease a Yasen for Chakra-3 but the request was turned down by the Russians.



I'd be glad if that were possible. To me, a 10,000t hull suggests a large, double-hulled sub of the Russian mould. A bigger hull means better quieting, more weapons and better crew facilities so no complaints. The Yasen is a more refined design than Akula.

Scaling a Suffren hull to 10,000t would not be practical (unless France wanted to share insights on their next-gen SNLE-3G missile sub - bigger boat based on Suffren) or cost-effective.

I wouldn't be surprised if the basic design for our SSN had been frozen already.

I meant on technologies only and India's first SSN (in house built) will not be 10K tone logically speaking. It seems to be error in reporting.

 

[_Anonymous_]

10,000 tons displacement
190 MW LWR
10-12 years

Seems we obtained blue prints of Akula.

In that case India'd be the only country to run SSNs with a bigger displacement than SSBNs

 

[Ankit Kumar]

Rumours say that the IN wanted to lease a Yasen for Chakra-3 but the request was turned down by the Russians.

Russians gave us option of leasing any 1 of 3 Akula hulls. We signed the deal. God knows how much we paid. When Indians went to inspect in 2021, all the 3 were found to be unfit for refurbishment. Recommendations were for scrapping them instead.

So yes, all hail Russian shipbuilding in the current times.

In that case India'd be the only country to run SSNs with a bigger displacement than SSBNs

It's 12 years away. We will have S5 before that in water.

 

[Speedster1]

I meant on technologies only and India's first SSN (in house built) will not be 10K tone logically speaking. It seems to be error in reporting.

Could be. But one reason why the CCS cleared 2+4 SSNs is likely because Project 77 is much more ambitious than the previous Project-76A. The focus seems to be on building a qualitative edge given that we can't match the PLAN on numbers.

Tech wise, I think we are pretty well placed on most aspects (with 90-05% IC) only design consultancy is being sought for some elements as per Rajat Pandit's report.

 

[Speedster1]

Russians gave us option of leasing any 1 of 3 Akula hulls. We signed the deal. God knows how much we paid. When Indians went to inspect in 2021, all the 3 were found to be unfit for refurbishment. Recommendations were for scrapping them instead.

Chakra-3 cost us $3b (refurb+ customization with Indian sensors, comms, etc). The Russians even proposed 3 'used' Kilo-class to make up numbers so they were/are clearly out to make a quick buck off us.

But no denying that they are investing heavily in N-subs and Yasen is off limits to even close allies.

 

[RISING SUN]

The focus seems to be on building a qualitative edge given that we can't match the PLAN on numbers.

I have observed this defeatist mentality in Indians generally speaking when it comes to compete against China, why?

Chinese SSN or SSBN fleet isn't so large quantitatively speaking that we can't match them in a decade or 2 if we commit to it early.

 

[Speedster1]

I have observed this defeatist mentality in Indians generally speaking when it comes to compete against China, why?

A few days ago, the new ACM himself used that infamous line, 'We will fight with whatever we have' to describe our situation vs the Chinese. During Kargil, it was Gen. Malik who said the same thing.

It's a question of priorities, more than anything else. China is single-minded in its focus towards building tech superiority over everybody else with the stated goal of Taiwan reunification and they have deeper pockets than we do.

To be fair, China is an authoritarian top-down regime that hands out capital punishment to those convicted of corruption. India, on the other hand, is a democracy with competing socio-political interests and all the compromises it entails. You can get away with a life sentence for corruption.

 

[Ankit Kumar]

Chakra-3 cost us $3b (refurb+ customization with Indian sensors, comms, etc). The Russians even proposed 3 'used' Kilo-class to make up numbers so they were/are clearly out to make a quick buck off us.

But no denying that they are investing heavily in N-subs and Yasen is off limits to even close allies.

Russians need subs in Baltic badly. The fact that they are not refurbishing those 3 Kilos for their own use shows how real the offer for those 3 Kilos were.

 

[RISING SUN]

A few days ago, the new ACM himself used that infamous line, 'We will fight with whatever we have' to describe our situation vs the Chinese. During Kargil, it was Gen. Malik who said the same thing.

It's a question of priorities, more than anything else. China is single-minded in its focus towards building tech superiority over everybody else with the stated goal of Taiwan reunification and they have deeper pockets than we do.

To be fair, China is an authoritarian top-down regime that hands out capital punishment to those convicted of corruption. India, on the other hand, is a democracy with competing socio-political interests and all the compromises it entails. You can get away with a life sentence for corruption.

All of these are my concern also. I refer you to Jeff statement that soft power (economy) didn't make or brought America the superpower status, it was the hard muscle and brute military strength which allowed America to gain business opportunities everywhere.

When are Indian policy makers going to get this common sense?

 

[South block]

Why not made this whole submarine out of titanium alloy.... India has one of the biggest reserve on earth & I am sure cost won't be much of a factor since 95% of submarine will be indigenous only. Think out of box & surprise your adversaries & World.

 

[mamiam23]

Why not made this whole submarine out of titanium alloy.... India has one of the biggest reserve on earth & I am sure cost won't be much of a factor since 95% of submarine will be indigenous only. Think out of box & surprise your adversaries & World.

Why bother when there are alloys with better performance?

 

[marich01]

Why not made this whole submarine out of titanium alloy.... India has one of the biggest reserve on earth & I am sure cost won't be much of a factor since 95% of submarine will be indigenous only. Think out of box & surprise your adversaries & World.

We still import the large part of titanium sponge from outside.

 

[South block]

Why bother when there are alloys with better performance?

Like what ?..... Using titanium alloys has long term benifits from low maintenance if done properly to making submarine lighter, faster with higher depth ratings........Very High corrosion resistance ( necessary for tropical rust furnace region of earth we live in & where our submarines going to operate for the most part )....helps in maintaining low acoustic & non-magnetic signature even as submarine Ages.

We still import the large part of titanium sponge from outside.

Scaling should not be a problem.... It's all about finding the right alloy & will.

 

[mamiam23]

Like what ?..... Using titanium alloys has long term benifits from low maintenance if done properly to making submarine lighter, faster with higher depth ratings........Very High corrosion resistance ( necessary for tropical rust furnace region of earth we live in & where our submarines going to operate for the most part )....helps in maintaining low acoustic & non-magnetic signature even as submarine Ages.



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Scaling should not be a problem.... It's all about finding the right alloy & will.

Read why US Navy doesn't use it. Note that they went as far as establishing shell companies for SR-71 Titanium Material. For the same US Navy with gigantic budget didn't opt for it. Neither did the UK Navy. There is plenty of material available for reading on r/submarines.

 

[South block]

Read why US Navy doesn't use it. Note that they went as far as establishing shell companies for SR-71 Titanium Material. For the same US Navy with gigantic budget didn't opt for it. Neither did the UK Navy. There is plenty of material available for reading on r/submarines.

They didn't adopted it because titanium was very hard to work with in past + manufacturing cost increase multiple folds due to economic system there....... not saying use titanium but at least consider it as an option. Why not build a mini test bed to test future technologies.

 

[marich01]

Scaling should not be a problem.... It's all about finding the right alloy & will.

Scaling is actually quite a large problem as the volume needed for these Ti alloys were always small compared to other steel grades, hence cost more if produced domestically and you won't be able to compete with the imported material pricing. Midhani themselves buy the sponge from Rus and other sources. The DMRL plant is for own consumption, very small capacity with little recycling of the Ti waste. Other than PTC Midhani there are not much good source as there was very little demand for such alloys. With more aerospace industry growth maybe the situation would change.

 

[marich01]

They didn't adopted it because titanium was very hard to work with in past + manufacturing cost increase multiple folds due to economic system there....... not saying use titanium but at least consider it as an option. Why not build a mini test bed to test future technologies.

The wastage were high and recycling the scrap metal to extract the Ti , such plant or facility were not present before. Ti is already brittle in room temp and needs really mature processing to recoup from the waste part. So high scrap volume + less volume demand meant higher pricing, aka it is far cheaper to import. Now all govt contracts you need mandatory quoting the indi % value addition be it tier 1 source >50 or tier 2-3 msme 20% , still need more domestic demand first.

 

[Speedster1]

Why not made this whole submarine out of titanium alloy.... India has one of the biggest reserve on earth & I am sure cost won't be much of a factor since 95% of submarine will be indigenous only. Think out of box & surprise your adversaries & World

Not a bad idea imo. Titanium is non-magnetic. Non-mag alloy tech is closely guarded. (Iirc only German and Italian Type 212/A have non-mag hulls. Export Type 214s do not. It's likely we won't get non-mag either, if we go with TKMS) But the cost is definitely a factor.

I think the Soviets, with their huge reserves, were the only ones to ever build Ti-hulled Sierra class SSNs but quickly gave up.

 

[Ankit Kumar]

Not a bad idea imo. Titanium is non-magnetic. Non-mag alloy tech is closely guarded. (Iirc only German and Italian Type 212/A have non-mag hulls. Export Type 214s do not. It's likely we won't get non-mag either, if we go with TKMS) But the cost is definitely a factor.

I think the Soviets, with their huge reserves, were the only ones to ever build Ti-hulled Sierra class SSNs but quickly gave up.

Titanium hulls like those used by Soviets also help the subs to dive deeper.

While the Type 212s have a limitation on diving depth. I think their non magnatic hull comes from different inspiration.