[V.Narayan]

Originally Posted by ads11

Speaking of AIP - do the Swedes not export? I've never seen any of their boats in the conversation, which seems odd given the strong reputation they have from the infamous exploits of the Gotland class in operation and in exercises.

The Swedish AIP based on a closed cycle low revving Stirling engine has been a success in their Navy but not exported yet. I think that might have something to do with the Swedes rarely being able to sell their otherwise excellent weapons to anyone outside the Western fraternity. Also their boats are designed for the shallow confined waters of the Baltic. On the one occasion they attempted to build a large boat {Collins class} they did not exactly make a success of it.

Another thought I had is how many of the contenders for the Collins class replacement programme would fit the bill for Project 75I? I wonder how much overlap there is between the two prospective contests.

I suspect the overlap must be high! The Germans had offered the Type 216 as a replacement.

Originally Posted by aim120

Btw that article from Tyler at TWZ states that Pakistan has AIB in their french origin submarines.

Yes the Pakistani's it seems have with French help fitted the MESMA system AIP into their last three boats named the Khalid class. MESMA as many may know is a steam turbine run on ethanol and oxygen compressed to 60 atmospheres. It on the whole sounds complicated and has not been adopted by anyone else. I cannot speculate on its reliability.

[narmad]

Originally Posted by V.Narayan

MESMA as many may know is a steam turbine run on ethanol and oxygen compressed to 60 atmospheres. It on the whole sounds complicated and has not been adopted by anyone else. I cannot speculate on its reliability.

This is the reason supposedly provided by DCNS to pull out of the P75I project.
The Indian requirement was of a working Fuel cell AIP.
French do seem to have Fuel cell AIP program based on metal hydride storage, but it is not in production.
IN never did like MESMA and rejected the option to fit it in the currently inducted scorpenes.

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Odd bit of news: looks like a Shyena torpedo of Indian design has washed up on a beach in Myanmar

TLDR:

1. From the colouring - most likely a training round. Visible lettering seems to corroborate this.
2. Prevailing theory is it's a round used by the Myanmar Navy (India sold them some). Timeline matches up with an exercise held in Rakhine Bay by Myanmar Navy. Sea conditions were poor that time too, would make retrieval difficult.
3. Long shot is it was used by the IN in an exercise in the Bay of Bengal and somehow ended up in Myanmar.

In any case, article covers some details on this domestic light torpedo.

[dragracer567]

The Indian Navy has decommissioned the INS Sindhudhvaj - a Kilo class submarine after 35 years of service. This submarine had at one point, reportedly managed to track an LA Class SSN - the USS City of Corpus Christi during the 2015 Malabar exercises with the US Navy - no small feat.



With this decommissioning, the Indian Navy is left with just 15 conventional submarines - a mix of kilo class, scorpene class and type 209 class submarines. The Indian Navy originally had acquired 10 kilo class submarines out of which which only 7 remain with 1 having sunk in an accident and another one handed over to the Myanmar Navy (IMHO, should've gifted this sub to a friendlier country like Vietnam rather than the Pro-Chinese Burmese junta).

The Indian Navy is effectively losing more submarines than inducting at this point with only 2 more Scorpene submarines on the horizon, the latest of which will be inducted early next year. This is while Project 75i has been stuck in a dead-lock where all the potential contractors have pulled out due to issues ranging from the requirement for a proven AIP system, the requirement for the Indian partner to have a majority share though the OEM is responsible for the delivery, shortfalls etc (same reason why the original MMRCA Rafale contract sank). I understand we Indians are tough negotiators but why put demands that literally scared every contractor away?

There is a bit of an irony here that India can effectively build an SSBN by itself but is struggling to build a conventional submarine. India is also hoping to get some SSNs, possibly with French or even American help.

The problem is though, while South Block sits around debating the pros and cons, issuing tenders that no one wants to participate in etc, the Indian Navy's number will continue to deplete with both the Kilo and type 209 classes being decades old.

I know this is taboo but I am inclined to say that the defense procurement policy of the current administration in the Post-Parrikar era has been absolute doldrums and is about as bad as the AK Anthony era - the only difference is in the nationalist marketing. The fact that the economy has been in decline since 2017 and is only now starting to pick up could be a reason for this. I understand that it is important in a democracy to ensure that the tax-payer money is spent fairly but decision paralysis leading to the most severe depletion of numbers in the 21st century in the Navy and Air Force will on the one hand make our armed forces relatively weak when called to respond to Pakistani and Chinese misadventures while on the other hand make us a less useless ally to the west/anti-China alliance - something our current foreign policy is really counting on.

I somehow feel that if India had set about designing its own conventional submarine 10 years ago, it would've been ready for induction by now - anecdotally, such has been the competence of our naval builders (I mean, we literally just built an aircraft carrier). So, why not rely upon and build our indigenous expertise instead of bickering while losing valuable time, expertise and equipment? Why can't a nation that built its own SSBN and aircraft carrier manage to build a diesel-electric submarine?

[V.Narayan]

Belgograd - Russia's new giant submarine

https://interestingengineering.com/r...worlds-largest
https://www.newsweek.com/how-russias...ld-war-1727599

The Russian Navy has taken delivery of what is the world's longest known submarine. Experts say its design is a heavily modified version of Russia's Oscar II class guided-missile submarines, made longer with the aim to eventually accommodate the world's first nuclear-armed nuclear powered stealth torpedoes and underwater drones (called Underwater Unmanned Vehicles) for intelligence gathering. At more than 184 meters (608 feet), the Belgorod is the longest submarine in the ocean today -- longer even than the US Navy's Ohio class ballistic and guided missile submarines, which come in at 171 meters (569 feet). At an estimated 24,000 tonnes of submerged displacement it is second in size only to the Russian Typhoon class ballistic missile submarine.

TASS has reported that the sub will carry the in-development Poseidon nuclear-capable torpedoes, which are being designed to be launched from hundreds of miles away and to sneak past coastal defences by traveling along the sea floor. This nuclear 'mega torpedo' is unique in the history of the world. The Poseidon is a completely new category of weapon. It will reshape naval planning in both Russia and the West, leading to new requirements and new counter-weapons. The Poseidon, which is expected to be 2 meters in diameter and over 20 meters and weigh ~30 to 45 tonnes.

Both US and Russian officials have said the torpedoes could deliver warheads of multiple megatons, causing radioactive waves that would render swathes of the target coastline uninhabitable for decades.

It is also claimed that the Belgorod can carry underwater drones for surveillance – very probable. And a carry piggy back a midget nuclear powered recce submarine weighing 100 tonnes – confusing. If it is nuclear powered midget sub why does it need to be carried piggy back to the target area unless it is very slow?

The Poseidon bottom crawler nuclear warhead on a atomic powered torpedo is to provide an additional threat to the Americans over and above the silo/submarine launched ballistic missile and the aircraft/ship/submarine launched cruise missile.

From a ship gazers point of view this is an exciting new development and quite an amazing boat. From an ordinary human's point of view yet another way to kill and maim. It is amazing how much we collectively spend on defence - $ 2.1 trillion. The Russians are showing that their capacity to be innovative & to think out of the box is far from dead.

To pre-address a question some may raise. The quality or competence of the Russian submarine force cannot and should not be judged by the stalemate their army is facing in Ukraine. It is like saying the rout of the Americans in Afghanistan is a reflection of the competence of their submariners or worse their SSBN fleet on patrol!



Belgorod, all 24,000 tonnes of her


The stern showing the twin shafts


Infographic presentation

[Jeroen]

We have discussed other nation submarine on this thread before, so I thought I would share this.
This weekend was world harbour event in the Rotterdam harbour. A huge maritime event. The Dutch navy was out in force with amongst other one of their Walrus class submarines, Zeeleeuw. Sealion



It is quite a formidable boat but tiny in comparison. Seen from the other side as a huge ferry boat made its way in past the spectators. You can barely spot it right behind HMSS Rotterdam the Dutch navy Support and supply ship. Left early to help escort some Russian war shops along the Dutch coast.

All these ships are open to the public, great event



The walrus class was build here in Rotterdam quite some years ago and should have been replaced. But the Dutch gouvernement keeps postponing the choice of vendor.

Jeroen

[dragracer567]

Originally Posted by Jeroen

It is quite a formidable boat but tiny in comparison.

All these ships are open to the public, great event

Attachment 2354942

Jeroen

According to wikipedia atleast, this one's bigger than both the Scorpene class and Type 209 class submarines of the Indian Navy though smaller than the Kilo subs.

The walrus class was build here in Rotterdam quite some years ago and should have been replaced. But the Dutch government keeps postponing the choice of vendor.

That sounds familiar

Unrelated to subs but I had the fortune of viewing the HNLMS Groningen up close on the River Scheldt in Antwerp. Funny that the Dutch call it an offshore patrol vessel - at 3,750 tonnes, it's bigger than the corvettes of most navies and even frigates of some countries - even had what seemed like an AESA radar.

[comfortablynumb]

The Boomer booms:

https://www.ndtv.com/india-news/indi...-facts-3431760

This must be a significant milestone, for the reason given below (taken from the article).

India's nuclear ballistic missile submarine INS Arihant successfully test-fired a ballistic missile today, a major milestone as earlier test-firings were done from fixed underwater pontoons; this time the submarine itself launched the missile

[V.Narayan]

Originally Posted by comfortablynumb

The Boomer booms:

https://www.ndtv.com/india-news/indi...-facts-3431760

This must be a significant milestone, for the reason given below (taken from the article).

Most certainly landmark news and a milestone in the development and operationalization of India's strategic deterrent. One one level is the three way interface of submarine + nuclear propulsion + underwater launched missile. At the second level is the integration of launching a missile underwater + inertial/satellite navigation of the boat so that the missile 'knows' the exact starting reference co-ordinates from which it commences its long journey to the target + marrying the missile with a nuclear warhead. That we accomplished both sets of integrations deserves a salute to the men & women of ISRO, DRDO, the Indian Navy and L&T.

The news does not mention which missile was fired - the 750kms ranged K-15 or the 3500 kms ranged K-4? Guess we will not know for a while. Ideally one day we need a ~5500 kms SSBN launched missile to cover all of China while lying in the Bay of Bengal.

[saikarthik]

Originally Posted by V.Narayan

5th Scorpene of Project 75 goes for sea trials
INS Vagir, the 5th Scorpene commenced sea trials a short while ago. Nice to see the underwater fleet growing steadily but one despairs it is too slow keeping in mind that the rest of the diesel-electric fleet is over 22 years old.

INS Vagir, the 5th Kalvari class (Scorpene) was handed over to the Indian Navy yesterday after sea trials including weapons and sensors trials. The Indian Navy tweet also mentioned that, this is the third submarine to join the fleet in 24 months which is much needed boost. Though we need to accept the fact that the project is 4 years behind it's actual schedule, still a great effort by the Mazagon Dock Shipbuilders Limited (MDL).

https://www.thehindu.com/news/nation...le66284661.ece

Originally Posted by V.Narayan

TASS has reported that the sub will carry the in-development Poseidon nuclear-capable torpedoes ---break--- The Poseidon bottom crawler nuclear warhead on a atomic powered torpedo is to provide an additional threat to the Americans over and above the silo/submarine launched ballistic missile and the aircraft/ship/submarine launched cruise missile.

It is also claimed that the Belgorod can carry underwater drones for surveillance – very probable. And a carry piggy back a midget nuclear powered recce submarine weighing 100 tonnes – confusing. If it is nuclear powered midget sub why does it need to be carried piggy back to the target area unless it is very slow?


Attachment 2338334
Infographic presentation

Sir, it's slightly confusing when they say 'nuclear powered' torpedo. Due to it's diameter of just 2 meters, I assume it's not a conventional small reactor that's powering the torpedo and if it's not a new generation of miniature reactor then do they mean it's nuclear isotope thermo-electric generators with batteries? This technology is used in space, but cannot generate great power.

And for the 'piggy back', could it be because of the crew and operations related strategy?

[V.Narayan]

Where submarine construction goes we seem to be making the same mistake we did in the 1990s. With the 6th of the Kalvari class {Scorpene} about to join the fleet our submarine construction expertise developed for a second time at Maz Docks is at risk of getting dissipated if we do not have 2 or 3 more of the Kalvari’s ordered yesterday. It is not just the skill of the workers at stake but also the supply chain that has been developed. This looks headed to be a repeat of the 1990s where the abilities developed with the two Type1500 were lost at the altar of budget shortfalls, indecisive Governments and moralistic posturing to our own detriment.

Today we have on paper 18 boats including the 2 SSBNs – 7 new, 1 middle aged and 10 old boats. Boats over 30 years old are old given the rigours the pressure hull must cope with. And we have only 1 SSK scheduled to be added and maybe 2 more SSBns

Compare this with Pakistan a country with a GDP smaller than Maharashtra who will have 4 Chinese AIP* equipped Hangor {Type 039B} class 2800 tonne boats due to enter service over 2023-2024 to be followed by a further 4 to be built in Pakistan. This will significantly add to their current fleet of 5 Agosta class boats.

What we need is a collaboration to build in India 6 to 8 SSNs. Such a collaboration could be with France or maybe even Japan if that country chooses to go down the nuclear powered path.

Originally Posted by saikarthik

It's slightly confusing when they say 'nuclear powered' torpedo. Due to it's diameter of just 2 meters, I assume it's not a conventional small reactor that's powering the torpedo and if it's not a new generation of miniature reactor then do they mean it's nuclear isotope thermo-electric generators with batteries? This technology is used in space, but cannot generate great power.

And for the 'piggy back', could it be because of the crew and operations related strategy?

I do not know enough. Who knows some of this could be misinformation. Technically the Russians can design & make a miniature atomic power plant. In the 1950s the Americans very seriously contemplated a nuclear powered bomber that would stay aloft for days! https://en.wikipedia.org/wiki/Nuclear-powered_aircraft

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There was a valid concern amongst many of us that the skills acquired through building the Vikrant would be lost if no follow on order was placed. Thankfully it seems a follow on is indeed being greenlit. One can only hope that after a minor delay, here too, we eventually see the much needed follow on orders for the Scorpene type boats. Or better yet we see a decision on Project 75I and maybe the yards can get started on work related to that.
But fully agree with the above worry though.

[V.Narayan]

5th Scorpene to commission on 23rd January ‘23

https://www.hindustantimes.com/india...144696666.html
INS Vagir, the 5th Scorpene submarine, Kalvari class, will formally commission into the Navy on 23-1-23 after completing its builder and user sea trials. Only one more remains to be commissioned, INS Vagsheer which is expected in 2024.


Photo of INS Vagir during its first sea trials


Navy may repeat the Scorpene order. Or so says this news article! I hope it is true

https://www.hindustantimes.com/india...416531671.html

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.

With the 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.

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. 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.

Our submarine strength is low and old. Modern navies typically keep submarines in service for 25 or maximum 30 years. 8 of our 17 submarines are 30 or more years older. This sad state of affairs has come to pass by many actions not taken in the 1990s and 2000s - not purchasing more Klub equipped Kilo's in the late 1990s and early 2000s; delaying the decision making on the Scorpene's in the 2000s; not pursuing the HDW Type 1500 in the 1990s has led to this.

In 1994 our strength was 21 submarines of which 14 were new. Our strength and ageing is the worst it has been since 1990.

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Originally Posted by V.Narayan

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.

Really hope the above comes to pass. Much much easier to just get an add on order for a system/platform that's already cleared all the checkpoints of Indian procurement than to start afresh and jump through all the hoops again.

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.

I think this is a totally acceptable compromise if it came to pass. Going off memory the key differentiating requirements of the Project 75I spec were AIP and cruise missile launch capability right? If the Kalveri frame is adapted with that DRDO developed AIP plug in module, that ticks off one key requirement, I guess the only omission is that land attack capability and IIRC the ability to have special forces operate off the boats. Considering the pressing need to have more hulls at sea to counter increasing under sea threats, surely some of those 75I wish list items will have to take a back seat in terms of the bigger picture, as well as keeping the shipyard ticking over with the skills that have been built up over the Kalvari class build.

I remember a few years ago seeing that DRDO AIP plug in module get some press/discussion but not heard anything since. Any news on how far along that project is?

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.

Has development on this started concurrent to the building of the remaining Arihant class boats or will it commence in a sequential order? Trying to get an idea of what sort of time frame is envisioned for the first boat of this class hitting the water. Also 3 boats seems a bit of a strange number, unless the plan is to follow the same rotation scheme as 1-1-1 of underway-refit-training.

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Guess I have my answer on how far along DRDO is with their AIP project. Seen this in a tweet.

https://www.livefistdefence.com/indi...ene-submarine/

The 1st boat INS Kalvari is going to be retrofitted with the AIP module. This'll change things I guess when it comes to how the IN proceeds with Project-75I, hopefully pushing towards a follow on build of a B-spec Kalvari-class.

Article raises a good point about the massive sunk cost at the yard for this 6 boat construction run and how even if 75I is greenlit, the orders wouldn't necessarily go to the same yard.