Indian nuclear submarines

[Aniruddha Mulay]

The making of the "Ghost Submarines" of India - Alpha Defense

The submarines under project 75 Alpha for the Indian Navy are ghost submarines in the making. They are stealthy.

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The making of the “Ghost Submarines” of India


The Indian SSNs will be fast, Silent and Lethal with Pump jet propulsion.

The hunter-killer under the sea that can wreck carnage in minutes, if the need arises. Fast, Lethal, and silent, this underwater warrior can change the course of any war and shift the strategic balance in no time. Often termed as silent service, the submarine arm of any Navy is one of the prime deterrence against the enemy. The SSNs (Submersible Ship Nuclear) – nuclear-powered general-purpose attack submarine is designed to protect the surface combatants and missile submarines and sinking other submarines, surface combatants, and merchant’s vessels.

Indian nuclear attack submarine program:

The Indian Navy plans to construct six advance new nuclear-powered attack submarines (SSN) under Project 75 Alpha in the coming years. The project was approved by the Government of India in February 2015. It is believed that these boats will be 6000 tonnes or lesser, INS Arihant like hulls but will be faster, stealthier, and will have a capability to dive deeper than Arihant class.

These will be designed by the Navy’s in-house Directorate of Naval Design based on Arihant class the submarines. The project will require comparatively lesser research and development as most of the technologies associated are already proven.

Development of these Submarines:

Though the submarine will be based on the Arihant class sub but the purpose for which these submarines are built is completely different. Thus, its natural design will require modification and optimization. As the power requirement is larger in this faster submarine thus the reactor rating could be higher or this need may be mitigated by a brand-new type of propulsion system. The current Arihant class of submarines uses an 83 MW miniaturized pressurized water reactor.

The government of India allocated INR 100 crore in June 2019 for the initial phase of the project and the preliminary designs phase is now complete. The Directorate of Naval Design and DRDO will now start working on the detailed design and construction phase of the program (Which hasn’t started yet).


The DRDO is currently working on multiple projects which appear to be associated with this project. These projects provide a good sneak peek into the design of the most awaited SSN of the Indian Navy. Let’s have a look one by one:

Sneak-peek into the design of Indian SSN:

1. Pump Jet Propulsion:

The most significant change likely will be in the propulsion system as the submarine is expected to move faster. Though a larger power rating reactor was also studied.

What is Pump jet Propulsion?

A pump-jet is a system that produces a jet of water for propulsion. The system comes in various configurations, but the basic principle is the same. The propeller blades or vanes are shrouded by the cowling. This cowling introduces multiple advantages such as:

1. Higher speed before the onset of cavitation, because of the raised internal dynamic pressure.
2. High power density (with respect to volume) of both the propulsor and the prime mover.

These advantages make this an obvious choice for the stealth submarines used in the attack mode.

Project 75 Alpha will have Pump jet Propulsion?

DRDO is currently working on Super Conducting Synchronous Motor for a Pump jet Propulsor. The current requirement is to develop a Scale down model for the Electric Motor (525 kW) as a Technology Demonstrator. However, the plan is to scale up to the requirement “upto” 35 MW.

For comparison, the Virginia class submarines of the US Navy also use a pump jet propulsion, and to drive the boat the SG9 reactor is used. The reactor drives a 30 MW pump-jet propulsion built by BAE systems. The Virginia class of submarines is 7,900 tonnes boats.


The SSN which India is building are ~6000 tonne and thus this scaling up likely is for an application. Which likely will be on the Project 75 Alpha.


Why this system is not for S4 and S5 class of submarine?

The S4 class of submarine are already under construction and the design of pump jet is still under prototype phase. On the other hand, the S5 class of submarines will be massive boats and will require far more power than a 35 MW pump jet. The speculated displacement of the boat will be 13,500 tonnes with a 190 MW reactor. Thus, the only available project in which this system can be used is SSN. Also, the pump jet is an obvious choice for a SSN over a SSBN.

2. Material for the Submarine

Mishra Dhatu Nigam or MIDHANI a public sector metal and alloy manufacturer located in Hyderabad is making special alloys in partnership with NMRL for this requirement that will not have any ferro magnetic qualities and will stronger than the current hull material of Arihant class to allow the SSNs dive deeper in the sea.

The possible material could be

1. Bulk Metallic glass: Bulk Metallic Glasses (BMG) have been found to exhibit very high strength, high elastic modulus, high corrosion resistance and several unique physical properties not observed in conventional crystalline metallic materials. This makes a potential choice for the outer hull of the submarine.
2. High Vibration Damping Aluminium Metal Matrix Composites: NMRL has developed molten flux assisted reaction synthesis foundry technology to produce high vibration damping aluminium metal matrix composites. Ultrafine reinforcement of graphite and ceramic particles such as Titanium Diboride (TiB2), Titanium Carbide (TiC), Boron Carbide (B4 C), etc.

Currently the material is used for the torpedo nosecone application and likely be modified for parts of the internal hull of a submarine to further reduce noise.

3. Stealth Material (Acoustic Stealth Material):

Vibroacoustic Tile: Vibroacoustic tile is used in the sonar dome of submarines to isolate the sonar transducers from structural vibrations and acoustic noise. This tile is also having a multi-layered configuration with perforated layers in the core, which are attached to each other by a specialty adhesive.

Variant of these tiles are also used below the engine and crew space to further shield any noise sneaking out of submarine.


Epoxy Putty: Epoxy-based putty is used for the levelling of surfaces and filling the gaps between metal to metal joints and for adhering metal to rubber surfaces. It provides excellent metal to rubber adhesion and has a service life of more than 20 years and is primarily used to adhere to acoustic rubber tiles onto the underwater surface of marine vessels.

The second generation of acoustic coating materials: These materials will be used to damp the low frequency sound as its these frequencies that let the secrets out.

1. Acoustic Rubber Tile MK3
2. Reinforced Coating
3. Noise silencer

Overall, the submarines under project 75 Alpha are ghosts in making.

Can someone clarify whether Project 75A is going to funded by the PMO like the ATV program or by the Navy's budget allocation?

 

[Tridev123]

Can someone clarify whether Project 75A is going to funded by the PMO like the ATV program or by the Navy's budget allocation?

It is Project 75I where I stands for India. 6 subs.
Very delayed programme. Highlight is that all the subs will have AIP and VLS capable of firing Brahmos. Will be bigger than the Scorpene.
Would be from the regular Navy budget.

All nuclear subs form part of the Strategic Forces and their construction is funded by the PMO. The programme is supervised by the PMO. Like the Space programme.

 

[Indx TechStyle]

It is Project 75I where I stands for India.

Project-75I is for conventional submarines. Project-75A (Alpha) is the one for nuclear attack submarines.

 

[Tridev123]

Project-75I is for conventional submarines. Project-75A (Alpha) is the one for nuclear attack submarines.

OK. So it means that the official designation of our SSN programme will be
Project A or Project Alpha
Will L & T play a big part in the construction of the SSN 's. Many Indians have more faith in their competence than in our public sector. Which Russian subs use Pump Jet propulsion(PJP).The Borei class SSBN' s or the Yasen class SSN's.

We know that some US nuclear subs use PJP technology. What about the latest French Barracuda class SSN's. Are the French collaborating with us on the SSN programme. They have fairly advanced technology. They can also share the reactor technology.

On a different issue Why the hell are we not finalising the torpedo choice for the Scorpene subs Since the sub is of French design choosing the French F21 heavy weight torpedo makes sense as integration with the sub combat system will be smooth.
Or are we waiting for the Varunastra HWT submarine variant to mature and enter service. The ship launched version has already been handed over to the Navy. I believe work is in progress on the submarine launched variant. It has a minimum range of 40 km.

 

[Indx TechStyle]

Will L & T play a big part in the construction of the SSN 's.

It will.

Which Russian subs use Pump Jet propulsion(PJP).The Borei

P-75A is inspired from Vanguard class submarines with Indian experiences, not Russian systems or any other involvement. At least till now.

On a different issue Why the hell are we not finalising the torpedo choice for the Scorpene subs

Waiting for indigenous alternative as you told.

 

[Tridev123]

It will.

P-75A is inspired from Vanguard class submarines with Indian experiences, not Russian systems or any other involvement. At least till now.

Waiting for indigenous alternative as you told.

Glad to hear that good performance is being rewarded (L & T). They deserve more work based on their track record.

Vangard nuclear submarines are British and use PJP. Design must be good. Even the Russian Borei class use PJP. As do the latest Barracuda class of France.

I hope we build the SSN's in batches of two. One each in two different shipyards. Like the SBC, Vizag and at L & T's shipyard. We all know that it may take up to a decade to commission the first batch. We need the SSN's ASAP to accompany the SSBN's on patrols.

 

[Aniruddha Mulay]

Glad to hear that good performance is being rewarded (L & T). They deserve more work based on their track record.

Vangard nuclear submarines are British and use PJP. Design must be good. Even the Russian Borei class use PJP. As do the latest Barracuda class of France.

I hope we build the SSN's in batches of two. One each in two different shipyards. Like the SBC, Vizag and at L & T's shipyard. We all know that it may take up to a decade to commission the first batch. We need the SSN's ASAP to accompany the SSBN's on patrols.

I have read news reports that the original capacity of SBC, Vishakapatnam is being upgraded from construction of 2 nuclear submarines simultaneously to 4 nuclear submarines simultaneously.
So, it is likely the P75A SSN will be built alongside S5 class SSBN.
Construction time for the SSNs is said to be 8 years from the start to being comissioned in the Indian Navy.

 

[Tridev123]

I have read news reports that the original capacity of SBC, Vishakapatnam is being upgraded from construction of 2 nuclear submarines simultaneously to 4 nuclear submarines simultaneously.
So, it is likely the P75A SSN will be built alongside S5 class SSBN.
Construction time for the SSNs is said to be 8 years from the start to being comissioned in the Indian Navy.

If confirmed very welcome news.
I think being capable of simultaneously building 4 nuclear subs is sufficient for our present needs.
But one aspect bothers me. By concentrating all nuclear submarines construction at one place, the SBC Vizag, are we not making it vulnerable. An enemy can think of sabotaging the infrastructure there and hence paralyse our entire nuclear sub programme. It would be wise to have at least two locations /facilities where we can manufacture nuclear submarines.

I am sure that the facility will be on the radar of the ISI and the Chinese PLAN.This is not to say that we have not taken precautions or put in place safeguards.

 

[WolfPack86]

Indian Navy to get second ballistic missile submarine
The Indian Navy will receive a major boost with the deployment of its second ballistic missile submarine. The INS Arighat is in the final stages of sea trials and is likely to be commissioned into service in early 2021.

Arighat is the second of the indigenous Arihant-class nuclear-powered ballistic missile-carrying submarine (SSBN).

Sources in the defense and security establishment said the submarine has performed well during the sea trials so far, and added that the commissioning of the vessel was delayed due to the coronavirus pandemic, according to Indian online newspaper The Print.

Once Arighat enters service, India will be operating two SSBNs that are equipped with the 750km-range K-15 ballistic missile, designed for retaliatory strikes in case of a nuclear attack.

The Arighat was quietly launched in November 2017 by the then Defense Minister Nirmala Sitharaman.

Both INS Arihant, which is on operational deployment, and the Arighat have the capacity to carry four missiles each.

While the original plan was to have four Arihant class submarines, it was changed by the UPA government, sources in the know said.

Now, the two Arihant class submarines will have a displacement of 6,000 tons while two other SSBNs will be of a larger size (7,000 tons displacement).

A key differentiating factor will be that the two larger vessels under construction — S4 and S4 at the Ship Building Centre in Visakhapatnam — will have eight missile tubes instead of four.

India currently also operates a nuclear-powered attack submarine (SSN) INS Chakra II, which is under lease from Russia.

It was in March last year that India and Russia signed a $3 billion deal for the lease of a third SSN — Chakra III — that is likely to be in Indian waters by 2025 at the earliest.

Russian submarines are being leased to train crews for India’s own fleet of SSBNs.

In 2015, the Narendra Modi government gave the green light to build six indigenous SSNs. About two years later, in 2017, then Navy chief Adm. Sunil Lanba had confirmed that work on the SSNs had started.

It was in November 2018 that India completed its nuclear triad when PM Modi announced to the world the completion of the first deterrence patrol by Arihant.

With that, India joined an elite group of countries that have the capability to launch a nuclear weapon from land, air and underwater. The only other countries capable of this are the US, Russia, China and France.

INS Arihant was commissioned in 2016 by then Defense Minister Manohar Parrikar, but a formal announcement came only two years later.

Indian Navy to get second ballistic missile submarine

The Indian Navy will receive a major boost with the deployment of its second ballistic missile submarine. The INS Arighat is in the final stages of sea trials and is likely to be commissioned into service in early 2021. Arighat is the second of the indigenous Arihant-class nuclear-powered...

www.defencenews.in

 

[abingdonboy]

It is Project 75I where I stands for India. 6 subs.
Very delayed programme. Highlight is that all the subs will have AIP and VLS capable of firing Brahmos. Will be bigger than the Scorpene.
Would be from the regular Navy budget.

All nuclear subs form part of the Strategic Forces and their construction is funded by the PMO. The programme is supervised by the PMO. Like the Space programme.

I don’t think SSNs will be funded by the PMO or the project monitored by them.


SSBNs are obviously strategic assets but SSNs are hunter killers, the PMO doesn’t really have much input in them at all.

 

[Tridev123]

I don’t think SSNs will be funded by the PMO or the project monitored by them.


SSBNs are obviously strategic assets but SSNs are hunter killers, the PMO doesn’t really have much input in them at all.

Seriously doubt it. All nuclear powered platforms have very sensitive technologies and are strategic in nature. An SSBN is a lumbering giant compared to a SSN which is far more agile.

Sending SSBN 's on patrol without being accompanied by SSN's is putting them at risk from enemy SSN's(here Chinese SSN's).

The original ATV programme which was the precursor to the Arihant was an SSN. The Chakra 1 nuclear submarine that we leased from Russia was also an SSN and not an SSBN. The entire ATV programme was directly under the control of the PMO(Mrs Indira Gandhi was the PM when the ATV program was sanctioned. Somebody can confirm it). All funding was controlled by the PMO and information was classified.

If you have information to the contrary please provide source.

 

[Tridev123]

Indian Navy to get second ballistic missile submarine
The Indian Navy will receive a major boost with the deployment of its second ballistic missile submarine. The INS Arighat is in the final stages of sea trials and is likely to be commissioned into service in early 2021.

Arighat is the second of the indigenous Arihant-class nuclear-powered ballistic missile-carrying submarine (SSBN).

Sources in the defense and security establishment said the submarine has performed well during the sea trials so far, and added that the commissioning of the vessel was delayed due to the coronavirus pandemic, according to Indian online newspaper The Print.

Once Arighat enters service, India will be operating two SSBNs that are equipped with the 750km-range K-15 ballistic missile, designed for retaliatory strikes in case of a nuclear attack.

The Arighat was quietly launched in November 2017 by the then Defense Minister Nirmala Sitharaman.

Both INS Arihant, which is on operational deployment, and the Arighat have the capacity to carry four missiles each.

While the original plan was to have four Arihant class submarines, it was changed by the UPA government, sources in the know said.

Now, the two Arihant class submarines will have a displacement of 6,000 tons while two other SSBNs will be of a larger size (7,000 tons displacement).

A key differentiating factor will be that the two larger vessels under construction — S4 and S4 at the Ship Building Centre in Visakhapatnam — will have eight missile tubes instead of four.

India currently also operates a nuclear-powered attack submarine (SSN) INS Chakra II, which is under lease from Russia.

It was in March last year that India and Russia signed a $3 billion deal for the lease of a third SSN — Chakra III — that is likely to be in Indian waters by 2025 at the earliest.

Russian submarines are being leased to train crews for India’s own fleet of SSBNs.

In 2015, the Narendra Modi government gave the green light to build six indigenous SSNs. About two years later, in 2017, then Navy chief Adm. Sunil Lanba had confirmed that work on the SSNs had started.

It was in November 2018 that India completed its nuclear triad when PM Modi announced to the world the completion of the first deterrence patrol by Arihant.

With that, India joined an elite group of countries that have the capability to launch a nuclear weapon from land, air and underwater. The only other countries capable of this are the US, Russia, China and France.

INS Arihant was commissioned in 2016 by then Defense Minister Manohar Parrikar, but a formal announcement came only two years later.

Indian Navy to get second ballistic missile submarine

The Indian Navy will receive a major boost with the deployment of its second ballistic missile submarine. The INS Arighat is in the final stages of sea trials and is likely to be commissioned into service in early 2021. Arighat is the second of the indigenous Arihant-class nuclear-powered...

www.defencenews.in

Bit puzzled. The article states that both Arihant and the Arighat have four launch tubes.

Now it was mentioned before that the Arihant can carry 12 K15 Slbm's. Or 4 K4 Slbm's. So what exactly is the weapon load of the Arihant and the Arighat. K15 or K4 missiles.

An weapon load of K15 missiles mean it is a Pakistan specific deterrent.
K4 missiles can also target parts of China.

 

[Nationalist Manasvi Papa]

Guys do you think India is understating tonnage of Arihant class and INS Vikrant?

 

[Cruise missile]

Bit puzzled. The article states that both Arihant and the Arighat have four launch tubes.

Now it was mentioned before that the Arihant can carry 12 K15 Slbm's. Or 4 K4 Slbm's. So what exactly is the weapon load of the Arihant and the Arighat. K15 or K4 missiles.

An weapon load of K15 missiles mean it is a Pakistan specific deterrent.
K4 missiles can also target parts of China.

Arihant can carry both k15 and k4. Each VLS tube can carry 3 k15 or 1 k4.

 

[Tridev123]

Arihant can carry both k15 and k4. Each VLS tube can carry 3 k15 or 1 k4.

I feel that Arihant carries only K15, twelve in number. About Arighat one is not sure, but 4 K4 missiles for China is insufficient.

 

[no smoking]

Guys do you think India is understating tonnage of Arihant class and INS Vikrant?

How can India understate the tonnage when you get so many foreign companies and government organizations involved.
And for what? Understating couple of hundreds ton is meaningless. Over 1000 tones, that is really hard and waste of money to play that trick. People can easily figure it out by looking at the pictures.

 

[AUSTERLITZ]

Arihant and Arighat with 12 k-15s each will be pakistan specific.The 2 successor subs with 8 K-5/6S will be china specific.After that true mega SSBN will come.

 

[no smoking]

Arihant and Arighat with 12 k-15s each will be pakistan specific.The 2 successor subs with 8 K-5/6S will be china specific.After that true mega SSBN will come.

The so called K-5/6s is still on the paper.

 

[vampyrbladez]

The so called K-5/6s is still on the paper.

They are under construction with K-5 launched.

 

[Killbot]

They are under construction with K-5 launched.

K-5 is the name of the 5000km SLBM. It isn't a sub.