Arihant-class SSBN - News & Discussions

How? Chinese have been building nuclear subs since the 70s tho it was an attack sub but the reactor tech is mostly the same ig.

Nuclear subs doesn't mean that it's mechanical parts will also be silent acoustically. One example: Simple propeller needs to be designed and coated with some materials in such a way that both suction side and vortex cavitation don't damage the propeller fins and create noise. They are very very loud on passive sonar detection.
 
  • Like
Reactions: Kimjongun
View attachment 52784
Not sure if this is S5

Where is this pic from?

Yes, it's one of the known S-5 models.


Bro, look where the raised 'hump' ends on the S4 and where it ends on the model. See how little space there is after the raised section on the model compared to S4. Perspective cannot account for all of it.

The taper toward the stern begins almost immediately after the raised section ends on the model. But not on the S4.


Those white/grey tube-like things on the model are test fixtures that attach to a control rig designed to keep it steady at a particular depth or to assist in pitch/yaw movements, like this:

PMM test submarine .png

SUBPMM_Otter.png

^^ The 2nd pic is an AUV but the principle is the same. It's called captive planar motion testing.

Those fixtures do not correspond to missile tubes. You can see there's one even all the way at the back of the raised section, where the reactor is supposed to be.

Hmm not sure why everyone thinks this image is of new S5 design though

Cuz the geometry of the raised section & the part of the hull behind it do not match with any existing boat.

An SSN even with VLS would not require a raised section, let alone one of this length. Hence, has to be SSBN.

How many SSBN programs are we working on who's design would not match with existing boats? Just one - the S5.

The original S5 model was seen for the first time in 2019. It wasn't inconceivable that some evolution may have happened between then and the first time this newer model was seen (2023-24).

Additionally, we now have confirmation that K-5 is making a huge leap in diameter (2.4m) of the missile body compared to K-4 (only 1.3m). In fact we know the diameter is going to be even bigger than Agni-5 (2.0m). This points toward a major effort to keep the length of the missile in check.

That corresponds well with the newer model having a much more streamlined hump than the previous one. It was likely redesigned keeping developments in the SLBM program in mind.

Note that all this is just me trying to connect the dots to draw a picture (that's what analysis is, for the most part). I cannot say that I 100% know for sure if this model is the S5, or if even the previous model was S5. For all I know, these are all just generic variations that we've been testing so that our hydrodynamic facilities gain as much workflow experience as possible.

For all I know, the real S5 design has never been seen by public.

But that's no fun. You must understand how tightly controlled these ATV program office images are. The number of actual ground-level photos that exist of the Arihant-class after over a decade of being in operation can be counting on the fingers of one hand. So when this office decides to randomly release an image, you have to think that it was done with a purpose.
 
Where is this pic from?

Yes, it's one of the known S-5 models.



Bro, look where the raised 'hump' ends on the S4 and where it ends on the model. See how little space there is after the raised section on the model compared to S4. Perspective cannot account for all of it.

The taper toward the stern begins almost immediately after the raised section ends on the model. But not on the S4.



Those white/grey tube-like things on the model are test fixtures that attach to a control rig designed to keep it steady at a particular depth or to assist in pitch/yaw movements, like this:

View attachment 52818

View attachment 52819

^^ The 2nd pic is an AUV but the principle is the same. It's called captive planar motion testing.

Those fixtures do not correspond to missile tubes. You can see there's one even all the way at the back of the raised section, where the reactor is supposed to be.



Cuz the geometry of the raised section & the part of the hull behind it do not match with any existing boat.

An SSN even with VLS would not require a raised section, let alone one of this length. Hence, has to be SSBN.

How many SSBN programs are we working on who's design would not match with existing boats? Just one - the S5.

The original S5 model was seen for the first time in 2019. It wasn't inconceivable that some evolution may have happened between then and the first time this newer model was seen (2023-24).

Additionally, we now have confirmation that K-5 is making a huge leap in diameter (2.4m) of the missile body compared to K-4 (only 1.3m). In fact we know the diameter is going to be even bigger than Agni-5 (2.0m). This points toward a major effort to keep the length of the missile in check.

That corresponds well with the newer model having a much more streamlined hump than the previous one. It was likely redesigned keeping developments in the SLBM program in mind.

Note that all this is just me trying to connect the dots to draw a picture (that's what analysis is, for the most part). I cannot say that I 100% know for sure if this model is the S5, or if even the previous model was S5. For all I know, these are all just generic variations that we've been testing so that our hydrodynamic facilities gain as much workflow experience as possible.

For all I know, the real S5 design has never been seen by public.

But that's no fun. You must understand how tightly controlled these ATV program office images are. The number of actual ground-level photos that exist of the Arihant-class after over a decade of being in operation can be counting on the fingers of one hand. So when this office decides to randomly release an image, you have to think that it was done with a purpose.
Might be the SSGN design based on the S4 class
Generated Image July 11, 2026 - 1_57PM.jpg
ATVP working on a new SSGN series reported by Sandeep Unnithan (Link to the Article)
Screenshot 2026-07-11 140229.png

If the S5 went from thisG0laHxhaMAUwos-.jpeg
to this
HIGyvTyaMAAsXjO.jpeg
Then it would've resulted in great delays due detailed design and refinements and a total configuration change instead S5 got into active construction last year itself.
IMO the S5 design only evolved towards making the Turtleback/hump integrate more seamlessly with rest of the hull
GcBloghbwAAXzx7.JPG

Similarities between Dreadnought and S5
7kw5ihzglsvg1.JPG
 
Might be the SSGN design based on the S4 class
View attachment 52820
ATVP working on a new SSGN series reported by Sandeep Unnithan (Link to the Article)
View attachment 52822

If the S5 went from thisView attachment 52823
to this
View attachment 52824
Then it would've resulted in great delays due detailed design and refinements and a total configuration change instead S5 got into active construction last year itself.
IMO the S5 design only evolved towards making the Turtleback/hump integrate more seamlessly with rest of the hull
View attachment 52826

Similarities between Dreadnought and S5
View attachment 52827
IMO* K6 will most likely be a 4 stage Slbm (3 stages + PBV) needing tall missile compartment which led to this tall and wide Hump
 
Might be the SSGN design based on the S4 class
View attachment 52820
ATVP working on a new SSGN series reported by Sandeep Unnithan (Link to the Article)
View attachment 52822

Maybe, we'll see.

If the S5 went from thisView attachment 52823
to this
View attachment 52824
Then it would've resulted in great delays due detailed design and refinements and a total configuration change instead S5 got into active construction last year itself.

Well, just because a model was seen in a particular year doesn't mean that's when it was developed. If the older S5 model (with large hump) was seen in 2019, it must've been in design for years before that point. Same for the new model.

IMO the S5 design only evolved towards making the Turtleback/hump integrate more seamlessly with rest of the hull
View attachment 52826

There've been several such CFD models, not all of which agree with each other.

FJpE33pXsAACL9s.jpg

It's not possible to know which is the newer or older version, or what each configuration was being tested for. For example, a model that's testing for NEP+backup reduction gear config could have a propulsion compartment that requires a larger bulkhead, closer to the dimensions of the missile compartment and giving the impression of a more streamlined hump as a result.

A model that's testing a reduction gear-only config could have a smaller diameter of the propulsion compartment, inversely making the hump look more pronounced.
 
Where is this pic from?

Yes, it's one of the known S-5 models.



Bro, look where the raised 'hump' ends on the S4 and where it ends on the model. See how little space there is after the raised section on the model compared to S4. Perspective cannot account for all of it.

The taper toward the stern begins almost immediately after the raised section ends on the model. But not on the S4.



Those white/grey tube-like things on the model are test fixtures that attach to a control rig designed to keep it steady at a particular depth or to assist in pitch/yaw movements, like this:

View attachment 52818

View attachment 52819

^^ The 2nd pic is an AUV but the principle is the same. It's called captive planar motion testing.

Those fixtures do not correspond to missile tubes. You can see there's one even all the way at the back of the raised section, where the reactor is supposed to be.



Cuz the geometry of the raised section & the part of the hull behind it do not match with any existing boat.

An SSN even with VLS would not require a raised section, let alone one of this length. Hence, has to be SSBN.

How many SSBN programs are we working on who's design would not match with existing boats? Just one - the S5.

The original S5 model was seen for the first time in 2019. It wasn't inconceivable that some evolution may have happened between then and the first time this newer model was seen (2023-24).

Additionally, we now have confirmation that K-5 is making a huge leap in diameter (2.4m) of the missile body compared to K-4 (only 1.3m). In fact we know the diameter is going to be even bigger than Agni-5 (2.0m). This points toward a major effort to keep the length of the missile in check.

That corresponds well with the newer model having a much more streamlined hump than the previous one. It was likely redesigned keeping developments in the SLBM program in mind.

Note that all this is just me trying to connect the dots to draw a picture (that's what analysis is, for the most part). I cannot say that I 100% know for sure if this model is the S5, or if even the previous model was S5. For all I know, these are all just generic variations that we've been testing so that our hydrodynamic facilities gain as much workflow experience as possible.

For all I know, the real S5 design has never been seen by public.

But that's no fun. You must understand how tightly controlled these ATV program office images are. The number of actual ground-level photos that exist of the Arihant-class after over a decade of being in operation can be counting on the fingers of one hand. So when this office decides to randomly release an image, you have to think that it was done with a purpose.
Iirc, the earliest depiction of S5's hull design was shown in a DRDO/NPOL brochure showcasing its integrated sonar suite much earlier (Defexpo 2014?).

S-5-1.jpg

Back then it featured a pronounced hump with blended sail, not much different from Delta 3/Type 094 Jin class boats. So the design has seen some iterations but I do not expect it to be a teardrop shape like Dreadnought or even the Ohio.
 
Iirc, the earliest depiction of S5's hull design was shown in a DRDO/NPOL brochure showcasing its integrated sonar suite much earlier (Defexpo 2014?).

View attachment 52825

Back then it featured a pronounced hump with blended sail, not much different from Delta 3/Type 094 Jin class boats. So the design has seen some iterations but I do not expect it to be a teardrop shape like Dreadnought or even the Ohio.

This is actually the original Project 935 Borei class design (not the Borei that finally got built, which was a fully redesigned sub under Project 955).

Projekt_955_Juri_Dolgorukij.jpg

This early iteration was planned as a direct successor to the Delta-IV, as you see the lineage clearly shows. Our agencies just reused that old design as a placeholder as they needed a graphic to display that sonar suite.

And who knows...maybe this Pr. 935 design was transferred to us 🤷‍♂️
 
K4 is deployed
K5 is sitting in hangar because doesn't fit inside current ssbns due to massive 2.4m diameter (pop up test was conducted recently)
K6 is in development
So k5 is still in development , pop up test does not mean the missile is cleared and is stting in a hanger , SLBMs are tested a lot to ensure no problems occur , K6 is planned
 
So k5 is still in development , pop up test does not mean the missile is cleared and is stting in a hanger , SLBMs are tested a lot to ensure no problems occur , K6 is planned
Atleast 4-6 pontoon tests will be done just like k4, first full range test might happen this year as per reports

Development program was completed last year then successfull S2 motor test and successfull pop up test this year means the missile is ready or under integration for first flight testG5ZHw20bEAA-mZm.jpeg
 
  • Like
Reactions: Kimjongun
Atleast 4-6 pontoon tests will be done just like k4, first full range test might happen this year as per reports

Development program was completed last year then successfull S2 motor test and successfull pop up test this year means the missile is ready or under integration for first flight testView attachment 52832
TBH i really like DRDO when it publishes some details of its missiles , unlike us who apart from tests dont see anything , kudos to them .
Are these propellents different from ones used in older agni missiles?
 
TBH i really like DRDO when it publishes some details of its missiles , unlike us who apart from tests dont see anything , kudos to them .
Are these propellents different from ones used in older agni missiles?
Most of the democratic countries publish this in other to have support among political class who in any democracy just wanna win election irrespective of the future of country.

So it's necessity in country like india, while its not in pakistan to get political support.
 
  • Like
Reactions: Kimjongun
This is actually the original Project 935 Borei class design (not the Borei that finally got built, which was a fully redesigned sub under Project 955).

View attachment 52831

This early iteration was planned as a direct successor to the Delta-IV, as you see the lineage clearly shows. Our agencies just reused that old design as a placeholder as they needed a graphic to display that sonar suite.

And who knows...maybe this Pr. 935 design was transferred to us 🤷‍♂️
Possibly. Its also possible that Igorr Spasky might have came up w/S5's design after having worked on the Arihant's. Rubin DB has had a long association with the IN going back to the Chakra I SSN.
 
  • Like
Reactions: Parthu
Man.....some of you put too much effort into a project shrouded behind secrecy. Some are over-zealously commenting & coming to conclusions over a limited set of photos. Have y'all ever thought that there might be half a dozen other hydrodynamic models that were never revealed??? What if S5 design is not based on any of the photos you all have posted. Just wait for the sub to be revealed in 2035.

TBH i really like DRDO when it publishes some details of its missiles , unlike us who apart from tests dont see anything , kudos to them .
Are these propellents different from ones used in older agni missiles?
Are you pakistani??? Mate i have questions for you:

1. How's the Afghanistan strategic depth project going?? Is there any sense of regret & anger towards the masterminds behind that??
2. Does the Pakistani awam really believe that India is behind BLA and other rebel orgs??? If yes, how do they rationalise the fact that - India closed all its consulates in Afghanistan (in 2021) that pakistanis used to get so angry about, and then the attacks in balochistan actually increased. How does that logic work???