Project-75I class SSK Submarines

[Blademaster]

Advantage to cost ratio of an AIP equipped SSK will always be far better than an SSN.

Not to mention the costs of disposal at the end of the life cycle of the sub. Nuclear sub decommissioning is one of the biggest expenses in the lifecycle of a nuclear sub.

 

[Abdus Salem killed]

Advantage to cost ratio of an AIP equipped SSK will always be far better than an SSN.

AIP ssk will be cheaper yes ?

 

[SilentlAssassin265]

Anything else?

Speed is almost twice, unlimited power, more depth, no need of fuel, ssk comsumes lot of fuel on full speed

 

[SilentlAssassin265]

SSKs are inherently much more silent then SSNs. AIP increases the underwater endurance of SSKs.

No not like that
In ssk you can turn off the engine to go completely silent and reduce IR signature drastically but in ssn IR signature will always be high.
But that doesn't mean all ssk will be quiter than ssn, seawolf class is one of the most silent sub even being ssn

 

[Arjun Mk1A]

Well we asked too much in RFI and most of the bidders does not everything ready. At least some sanity strikes and now Navy is going with Kalvari class. In coming years we can try to build indigenous one with all features we required in P75I.

This is another LCH saga where no helicopter available to do operations at that altitude which results in HAL working their ass to build an product. I hope simillarly Naval Shipyards will come with suitable product in this decade

 

[Chinmoy]

No not like that
In ssk you can turn off the engine to go completely silent and reduce IR signature drastically but in ssn IR signature will always be high.
But that doesn't mean all ssk will be quiter than ssn, seawolf class is one of the most silent sub even being ssn

inherently
adverb

UK

/ɪnˈher.ənt.li/ /ɪnˈhɪə.rənt.li/ US

/ɪnˈhɪr.ənt.li/

in a way that exists as a natural or basic part of something:
There's nothing inherently wrong with his ideas.
She felt that the system was inherently unfair and unequal.

https://dictionary.cambridge.org/dictionary/english/inherently

 

[Indx TechStyle]

AIP ssk will be cheaper yes ?

Yes
The role of SSK was to be used for seas around shores while SSN submarines for very long endurance missions.

Development of AIP has boosted endurance of SSK and thinned the gap of operational capabilities with SSN capabilities. Regardless of it, SSN being enormously durable dur to nuclear fuel, will remain a bigger tool of power projection.

 

[johnj]

IN wants everything in P-75I. The problem is no present submarine fulfills their criteria. They have to settle for less because no manufacturer is actively participating in this tender due to its requirements and clauses.

South Korea

 

[SilentlAssassin265]

South Korea

Drdo aip can't be retrofitted in this sub as hull needs to be cut open

 

[johnj]

Drdo aip can't be retrofitted in this sub as hull needs to be cut open

Unfortunately, only south korea offering submarine to IN.
South Korean sub comes with aip, li-ion batteries and vls [if required] and meet IN needs. No need for drdo aip.

 

[SilentlAssassin265]

Unfortunately, only south korea offering submarine to IN.
South Korean sub comes with aip, li-ion batteries and vls [if required] and meet IN needs. No need for drdo aip.

Yes but thats not the only issue .
Navy has given very strict timeline for 1st submarine delivery and has added penalty for delays, hence all bidders are opting out

 

[Javelin_Sam]

I think some work in Naval HQ happening towards scorpene/or a derivative of scorpene in partnership with French that uses desi AIP. There will not be smoke without some fire. Last year, Navy was replacing lead acid batteries of one Kilo sub with Li-ion batteries. DRDO NTSL Vishak had developed a high capacity Li-ion battery technology and was scouting for industrial partners to manufacture and test 25 numbers of this. If it succeeds, then there is no logic in going for DRDO's fuel cell AIP which will have very slow cruise speeds. The same space that it takes can be better utilised with Li-ion batteries. Better speed, better range.
The latest Teigei class sub by Japs also follows the same concept.

Laid down in 2018,
Launched in 2020,
Commissioned in 2022

 

[johnj]

Yes but thats not the only issue .
Navy has given very strict timeline for 1st submarine delivery and has added penalty for delays, hence all bidders are opting out

In that case. navy can say goodby to new ssk - both foreign & local.
Maybe IN want foreign yard to build submarines or hate ssk and only want ssns, lol.

 

[johnj]

I think some work in Naval HQ happening towards scorpene/or a derivative of scorpene in partnership with French that uses desi AIP. There will not be smoke without some fire. Last year, Navy was replacing lead acid batteries of one Kilo sub with Li-ion batteries. DRDO NTSL Vishak had developed a high capacity Li-ion battery technology and was scouting for industrial partners to manufacture and test 25 numbers of this. If it succeeds, then there is no logic in going for DRDO's fuel cell AIP which will have very slow cruise speeds. The same space that it takes can be better utilised with Li-ion batteries. Better speed, better range.
The latest Teigei class sub by Japs also follows the same concept.

Laid down in 2018,
Launched in 2020,
Commissioned in 2022
View attachment 189281

Then why not new hybrid kilo with li-ion batteries ? it saves 3 years or more and HSL having additional space to build subs

 

[BON PLAN]

What's the advantage of diesel electric with AIP as compared to nuclear attack
Is it just the endurance?

SSK are more silent, far less costly, but less max speed and far less average speed.
And the support cost of a SSN is also more important.

 

[BON PLAN]

AIP increases the underwater endurance of SSKs.

Yes, but only at a very small speed (ie 3 weeks at 4 to 5 knots, more or less).
A SSN can travel at +/- 25 knots for weeks (but at those speed it is probably blind due to hydrodynamic noise).

 

[BON PLAN]

Advantage to cost ratio of an AIP equipped SSK will always be far better than an SSN.

Yes and no. If you need a sub able to track a carrier cruising at 20 knots without clear datas on its position, a SSK even with AIP will be short, so not cost effective.

The best solution is probably to have the two.... Russia and China chose that, but not USA. Note that USA has the best experience in the field.

 

[Javelin_Sam]

Then why not new hybrid kilo with li-ion batteries ? it saves 3 years or more and HSL having additional space to build subs

Whats the reason to persist with a soviet era design? Also the kilo is small and there will not be much space to carry large number of batteries

 

[Indx TechStyle]

Yes and no. If you need a sub able to track a carrier cruising at 20 knots without clear datas on its position, a SSK even with AIP will be short, so not cost effective.

The best solution is probably to have the two.... Russia and China chose that, but not USA. Note that USA has the best experience in the field.

Off course a special case but given how many countries have carriers and how they use it, SSK with AIP is suitable most of likely scenarios (unless you are dealing with USA).

USA operates all N submarines. Given its immense experience with nuclear subs, it would have worked out some tech to compensate for SSK advantages.

 

[WolfPack86]

Indian Navy may repeat Kalveri class submarine order
Indian Navy is all set to bury fresh acquisition under Project 75 I and may go for repeat Project 75 order to MDL with DRDO proven and tested air independent propulsion system fitted into the new submarines under “Aatmanirbhar Bharat.”

New Delhi: When visionary Manohar Parrikar was the Defence Minister of India, he had suggested to then Navy Chief Admiral Robin K Dhowan that Indian Navy should exercise the option of three more Kalveri (Scorpene) class rather than go for fresh acquisition of six of Project 75 I, air independent propulsion equipped, submarines. Admiral Dhowan did not agree because of which the options clause for Project 75, which was approved by Atal Behari Vajpayee government way back in 2003, was cancelled in September 2016.

On July 20, 2021, the Ministry of Defence floated a request for proposal (RFP) for AIP equipped six Project 75 I class submarines at the cost of ₹40,000 crore. Since it is normal for Indian military-civilian bureaucracy to take at least 10-15 years to complete any big acquisition, it means that the current Scorpene submarine line at MDL will go to seed with the next set of 75 I class being built in late 2030s with a fresh massive investment on submarine line. All this appears to be set for a change.

In the meantime, the AIP equipped submarines have been superseded by the latest Soryu class Japanese submarines with higher endurance lithium-ion batteries with faster re-charge capabilities. The lithium-ion batteries have double the storage capacities of traditional lead acid batteries because of which the range of the submarine increases considerably. Given that the French have moved to nuclear propulsion and the German to lithium-ion technology ahead of AIP submarine technology, the Modi government most likely will end up with a single vendor option with South Korea being the only country building AIP submarines. Simply put, this means that by the time the Indian bureaucracy finalizes the vendor, the technology will be outdated and outclassed by the rapidly advancing Chinese PLA Navy.

With PLA Navy rapidly advancing into Indo-Pacific and the QUAD preparing to meet the challenge, the Indian Navy’s leadership is rethinking on its submarine options and may ask the Modi government to repeat the order of Kalveri class submarines with DRDO proven and French Naval Group tested AIP system fitted into the next six submarines. The Indian Navy’s big picture plan for the next 25 years includes design, development, and construction of three nuclear power conventionally armed submarines or what is called nuclear attack submarines or SSNs.

India currently has two nuclear powered ballistic missile fir8ing submarines or SSBNs with the third one under fitment.

The repeat order of Kalveri class submarines will ensure that Indian submarine building and machine tooling skills do not die after the last of Kalveri class submarines is commissioned this year and MDL later exports the same submarines to other countries in Southeast Asia like Indonesia and in Africa. The way out is to give a quiet burial to Project 75 I and build on existing Project 75 with indigenous DRDO developed AIP. The same AIP can be later retrofitted into Kalveri class submarines during mid-term life upgrade. Given that China is launching six to ten warships including submarines each year, India has no other option of meeting the Indo-Pacific challenge.

Indian Navy may repeat Kalveri class submarine order

Indian Navy is all set to bury fresh acquisition under Project 75 I and may go for repeat Project 75 order to MDL with DRDO proven and tested air independent propulsion system fitted into the new submarines under “Aatmanirbhar Bharat.”

www.hindustantimes.com

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