India's 5th S-4 Class SSBN, Armed With K-5 SLBM Missiles, Completes 50% Construction

In a significant boost to India's naval capabilities, the construction of the fifth S-4 class nuclear ballistic missile submarine (SSBN) is reportedly progressing steadily at the Ship Building Center (SBC) in Visakhapatnam. This new addition will elevate the Indian Navy's fleet of nuclear ballistic missile submarines to a total of five units, further solidifying the country's strategic deterrence.

The existing SSBNs, INS Arihant and INS Arighat, are sister ships with a submerged displacement of around 6,000 tons. While they share the same basic design, INS Arighat boasts significant internal upgrades, making it more advanced than its predecessor.

The S4 and S4* (Star), successors to the Arihant class, feature a stretched design and a submerged displacement of approximately 7,000 tons. Satellite images have captured these submarines at the outdoor fitment area at the SBC, offering glimpses into their development. Although this is the first official confirmation of a fifth submarine under construction, it is highly probable that its development is well underway.

Considering the S4's rollout from dry docks in 2022, it is estimated that the fifth submarine might already be over 50% complete. Nevertheless, it could still take a couple of years before it transitions from dry docks to the outdoor fitment area for further construction and sea trials.

The S4, S4*, and the unnamed fifth SSBN will mark a crucial milestone as the first Indian nuclear submarines equipped with the K-5 submarine-launched ballistic missiles (SLBMs). These missiles possess a range of 5000 kilometers, substantially bolstering India's nuclear deterrence capabilities.

In addition to these developments, the Indian Navy is also planning to develop the S5 Class of SSBNs, featuring a submerged displacement of around 13,000 tons. The S5 Class program is expected to gain momentum in the coming years, with the first submarine slated for induction in the mid-2030s. These submarines will reportedly be armed with K-6 SLBMs with a range exceeding 6000 kilometers and the highly classified K-8 missiles.

 

[SK]

This is a good news.

Indian-Govt should focus on developing SLBMs with a range of 10,000 Km as currently developing any ICBM with 10,000 Km range can lead to Major opposition from Western World.

Slowly & Steadily develop Strategic capabilities for:-
(1) Nuclear Energy & Weapons
(2) Space Launch Vehicles & Ballistic Missiless
(3) Space Program, Security & Warfare.
(4) Cybersecurity & Warfare

 

[sanket]

Very Good News indeed why not 6 instead of 5 , second S5 class of SSBNs of 13000 Tonne how much subs to b built ............?? Nice to know that S4 & S4* will b euipped with k-5 SLBM with 5000 kM Range & S5 class with SLBM k-6 with Range 6000 kM & super secret k-8

 

[Apocalypse gupta]

Put conventional warhead on these missiles as well, so these submarines can be used in conventional conflicts as well instead of just being weapons of last resort and used in nuclear conflicts. Too much money has been spent on them to just be paperweights until nuclear armageddon happens.

 

[Anant]

Very Good News indeed why not 6 instead of 5 , second S5 class of SSBNs of 13000 Tonne how much subs to b built ............?? Nice to know that S4 & S4* will b euipped with k-5 SLBM with 5000 kM Range & S5 class with SLBM k-6 with Range 6000 kM & super secret k-8

Three ships planned in the S5-class, atleast based on available information.

Also, I am not entirely sure if S4, S4*, and this unconfirmed fifth Arihant-class boat will carry the K5. By all indications based on available parameters, the K5 would be a larger (as in, wider and/or longer) missile than the K4, and therefore, unless the latter Arihant-class boats have a larger hull or larger missile tubes, I have a feeling the K5 wouldn't fit.

That said, whole larger tubes are definitely possible, bringing those in (leading to a larger hull) as well as doubling the number of missile tube would be expected to lead to a displacement increase that would be more than the 1,000 tons that we are seeing. Moreover, based on what I have been able to analyse from satellite footage of Visakhapatnam (footage that is somewhat old now), S4 doesn't seem to have larger missile tubes.

Regardless, I would be very happy if the Arihant-class can, in fact, carry the K5. It would be a much-needed boost to our nuclear deterrence and second strike capabilities, especially of China or Bhikaristan try something nonsensical.

 

[desigandu]

Three ships planned in the S5-class, atleast based on available information.

Also, I am not entirely sure if S4, S4*, and this unconfirmed fifth Arihant-class boat will carry the K5. By all indications based on available parameters, the K5 would be a larger (as in, wider and/or longer) missile than the K4, and therefore, unless the latter Arihant-class boats have a larger hull or larger missile tubes, I have a feeling the K5 wouldn't fit.

That said, whole larger tubes are definitely possible, bringing those in (leading to a larger hull) as well as doubling the number of missile tube would be expected to lead to a displacement increase that would be more than the 1,000 tons that we are seeing. Moreover, based on what I have been able to analyse from satellite footage of Visakhapatnam (footage that is somewhat old now), S4 doesn't seem to have larger missile tubes.

Regardless, I would be very happy if the Arihant-class can, in fact, carry the K5. It would be a much-needed boost to our nuclear deterrence and second strike capabilities, especially of China or Bhikaristan try something nonsensical.

Couple of thoughts - 1. If we get 5 SSBN boats in this phase, great but could mean S5s/13000 ton are being pushed back either because the 190mw reactors may not be ready in 3 years or to focus on SSNs (note both our ssbns and SSNs are of similar size 6/7000 tons difference being reactor size and VLS tubes for SLBMs which could be reduced for SLCMs…2. Once we have plans for 3 S5s starting 2035, the S2/3 could be converted for training/ or SSGNs, though they have limited VLS capacity…

By 2050 if our nuclear sub fleet can operate 6-8 SSBNs + 2-4 SSGNs + 6-8 SSNs plus 36 SSKs and other unmanned platforms we could dominate IOR…expensive but doable with 2 shipyard strategy in place by 2030 with the P76 program + SBC rolling out 1 nuclear boat/year from 2040…

 

[Sanjib Pathak]

Very Good News indeed why not 6 instead of 5 , second S5 class of SSBNs of 13000 Tonne how much subs to b built ............?? Nice to know that S4 & S4* will b euipped with k-5 SLBM with 5000 kM Range & S5 class with SLBM k-6 with Range 6000 kM & super secret k-8

When S5 class SSBN become operation we can convert the earlier Arihant clss subs into SSGN carring large number of cruise Missile.4 Operational S5 SSBN each armed with 12 K6 and K8 Missiles are sufficent for effective second strike capability against both China and Pakistan.

 

[Superpower Bharat]

Three ships planned in the S5-class, atleast based on available information.

Also, I am not entirely sure if S4, S4*, and this unconfirmed fifth Arihant-class boat will carry the K5. By all indications based on available parameters, the K5 would be a larger (as in, wider and/or longer) missile than the K4, and therefore, unless the latter Arihant-class boats have a larger hull or larger missile tubes, I have a feeling the K5 wouldn't fit.

That said, whole larger tubes are definitely possible, bringing those in (leading to a larger hull) as well as doubling the number of missile tube would be expected to lead to a displacement increase that would be more than the 1,000 tons that we are seeing. Moreover, based on what I have been able to analyse from satellite footage of Visakhapatnam (footage that is somewhat old now), S4 doesn't seem to have larger missile tubes.

Regardless, I would be very happy if the Arihant-class can, in fact, carry the K5. It would be a much-needed boost to our nuclear deterrence and second strike capabilities, especially of China or Bhikaristan try something nonsensical.

K4 can carry 2.5 ton warhead. With reduced weight around 1.5 ton and with slight modifications in missile the K4 can go beyond 5000 km... I think this new missile name k5 with same dimension

 

[op gupta]

There is so much misconception regarding pump-jet technology for upcoming ssn project although these are less noisy but only at high speed while at low these are just "Drag"- more noise, producing more cavitation and these are less fuel efficient. Besides it is not a new tech to be taken seriously it is a very old tech.

 

[Sandeep]

While it’s always good news that we will increase the number of the Arihant class of submarine we will make however, this should not come at the cost of reducing the number of the much larger S5 class SSBN we have been developing and we need. We need more larger submarines that can hold more and longer range missiles which the Arihant class can’t carry as these submarines will be needed against China primarily.

We also can’t afford to not construct these submarines and can’t delay them either because they are a critical necessity to ensure national security. Our security threat is changing and no matter what delaying what we essentially need will cost more later on and the technology will get older and may become outdated.

 

[Anant]

K4 can carry 2.5 ton warhead. With reduced weight around 1.5 ton and with slight modifications in missile the K4 can go beyond 5000 km... I think this new missile name k5 with same dimension

Let's see, boss. Considering the size escalation from the Agni I to the Agni III, I have a feeling the K-5 will be larger.

 

[Anant]

Couple of thoughts - 1. If we get 5 SSBN boats in this phase, great but could mean S5s/13000 ton are being pushed back either because the 190mw reactors may not be ready in 3 years or to focus on SSNs (note both our ssbns and SSNs are of similar size 6/7000 tons difference being reactor size and VLS tubes for SLBMs which could be reduced for SLCMs…2. Once we have plans for 3 S5s starting 2035, the S2/3 could be converted for training/ or SSGNs, though they have limited VLS capacity…

By 2050 if our nuclear sub fleet can operate 6-8 SSBNs + 2-4 SSGNs + 6-8 SSNs plus 36 SSKs and other unmanned platforms we could dominate IOR…expensive but doable with 2 shipyard strategy in place by 2030 with the P76 program + SBC rolling out 1 nuclear boat/year from 2040…

Sir, I have a feeling that the S5-class is also getting pushed a bit due to cost. SSBNs are extremely expensive assets. As it is, each Arihant-class submarine costs north of 3.5 billion USD, and even more once you factor in inflation.

Sir, 1 nuclear boat per year is outright impossible. We simply cannot place the quantum of orders needed for that.

 

[Anant]

Put conventional warhead on these missiles as well, so these submarines can be used in conventional conflicts as well instead of just being weapons of last resort and used in nuclear conflicts. Too much money has been spent on them to just be paperweights until nuclear armageddon happens.

Any missile carrying a nuclear warhead can also just as easily carry a conventional warhead. I have a feeling we would already be having some conventional warheads for these missiles.

 

[NSR]

S4,, S4* and S5 SSBNs would surely create a true nuclear triad.
S5 class submarine is the one India should be deploying against criminal china.

Way to go Indian Navy, my hats off to you.

 

[GMR]

13,000 tons ... wow for India.. go for pump jet

 

[Superpower Bharat]

Let's see, boss. Considering the size escalation from the Agni I to the Agni III, I have a feeling the K-5 will be larger.

Technology evolve many fold since Agni 3

 

[Tanishq Bafila]

Put conventional warhead on these missiles as well, so these submarines can be used in conventional conflicts as well instead of just being weapons of last resort and used in nuclear conflicts. Too much money has been spent on them to just be paperweights until nuclear armageddon happens.

They get a mix of weapons from conventional to nuclear warheads depending upon missions.. They are always on some missions assigned to them by Navy Officials..

 

[Man-ju]

13,000 tons ... wow for India.. go for pump jet

Pump jet is more for SSN, anyways the 13000 tonne subs might take a decade for induction. Maybe put on a back burner since we ordered the 5th SSBN.

 

[Sunil Choan]

Must be built in India with Full control no foreign influence

 

[Man-ju]

The current arihant class subs(with displacement 6000 tonnes) have a Pressurized water reactor with a output of 83MW developed by BARC. However BARC is working on fine tuning the same PWR on increasing the output to over 90MW so that S4 and S4*(with displacement 7000 tonnes) can be powered. It is believed same upgraded PWR will be used for our SSN program. So the next sub launch will be a big deal not this one as INS Arighat carries a few equipment upgrades compared to Arihant. I guess this is exactly what India is pushing for NSG membership(blocked by China) so that we can further improve our miniature pressurized water reactor to generate an output excess to 180MW to operate larger subs like UNSC permanent members. Even the Russians never allowed us to study the reactor of INS Chakra(Akula class).

 

[rtnguy]

There are already 2 deployed Arihant class submarines with Arighat being the 3rd . S4, S4* and another S4 will take India total nuke sub count to 5 before 2030 and with S5 joining post 2030, India will have 6 deployed nuke ballistic missile subs, Impressive, but ideally we should have double that number.

 

[M S Chatterji]

Where are we in the Attack submarine design and manufacture. The key item of this is 150-180MWe reactor. Is it ready or still under development?

 

[tipoo2]

Put conventional warhead on these missiles as well, so these submarines can be used in conventional conflicts as well instead of just being weapons of last resort and used in nuclear conflicts. Too much money has been spent on them to just be paperweights until nuclear armageddon happens.

The tricky thing is, when a boomer submarine pops up and lobs a missile at you that is potentially nuclear, how do you respond

The point of SSBNs is a very well hidden last strike capability, as in such a large scale war nuclear silos would be prime targets and our air portion of the triad is carried by old jets with only gravity bombs.

 

[Frank]

Pump jet is more for SSN, anyways the 13000 tonne subs might take a decade for induction. Maybe put on a back burner since we ordered the 5th SSBN.

What's the ssn capacity?? And any timeline given by navy??

 

[Rational Guy]

Put conventional warhead on these missiles as well, so these submarines can be used in conventional conflicts as well instead of just being weapons of last resort and used in nuclear conflicts. Too much money has been spent on them to just be paperweights until nuclear armageddon happens.

Make them carry sea launched hypersonic/ballistic conventional missile which can reach targets in Tibet when launched from Bay of Bengal

 

[Rational Guy]

This is a good news.

Indian-Govt should focus on developing SLBMs with a range of 10,000 Km as currently developing any ICBM with 10,000 Km range can lead to Major opposition from Western World.

Slowly & Steadily develop Strategic capabilities for:-
(1) Nuclear Energy & Weapons
(2) Space Launch Vehicles & Ballistic Missiless
(3) Space Program, Security & Warfare.
(4) Cybersecurity & Warfare

Also critical areas such as AI and semiconductor

 

[Rational Guy]

S4,, S4* and S5 SSBNs would surely create a true nuclear triad.
S5 class submarine is the one India should be deploying against criminal china.

Way to go Indian Navy, my hats off to you.

Even without S5 if we have 4000-5000 km SLBM in subs then it is easy to deter the bats.

 

[NSR]

Even without S5 if we have 4000-5000 km SLBM in subs then it is easy to deter the bats.

First two can only hold 4 3,500 kms SLBMs.
Perhaps if they improve these missiles propulsion system and size, it may be possible.

 

[desigandu]

Where are we in the Attack submarine design and manufacture. The key item of this is 150-180MWe reactor. Is it ready or still under development?

Anyone can give insights on the 190MW. B2/3 BARC reactor for alpha and potentially S5s?

 

[desigandu]

What's the ssn capacity?? And any timeline given by navy??

6000 ton, similar in size to Arihant, potentially the same shape with a bigger/ more powerful reactor of 190mw with either French/desi pumpjets, but adjustments in space elsewhere - either removal of VLS cells with missile capability via torpedo tubes like the French SSNs or larger size like S4s with VLS for LACMs,- all based on reading only, so no official repress release…but my sense is small displacement SSN given we don’t have powerful reactors…