Project 75 India Diesel-electric Submarine Programs (SSK) : Updates and Discussions

[randomradio]

What specifically, in your mind, makes a submarine obsolete. Because working with underwater systems has shaped for me a different view.

That's because you are talking about upgrading old subs. Whereas the discussion is about purchasing a new class of subs.

Old subs can comfortably continue to operate within the constraints of their design through upgrades. When it comes to new subs, it's all about new materials, new designs, greater performance. We want our new sub to move faster, farther and deeper, carry more etc, which is not all possible with existing designs.

New sub classes, in certain cases, come with the advantage of a higher level of funding than normal. For example, the SMX Ocean was a product of France's nuclear program. So the benefits are passed on to the conventional version, like pumpjet propulsion.

Right now, the navy has the option of either splurging on our future SSK or being more conservative with the SSK purchase because of the SSN program and the urgency to have more new subs. While the other 3 competitors do not have as many options to offer, depending on how it pans out, the French can either choose to participate with the SMX Ocean or a bigger Scorpene. But, rest assured, older designs are not going to make the cut, hence obsolete.

 

[advaidhya]

Our officers have various opinions. The navy is split between using proven Russian the while the French subs have more modern man-machine interfacing. So, indeed, the Russians have lost a lot in that front.

But both sides agree that the Russian sub is more versatile. Primarily because the Russian sub will come with an 8-cell VLS for Brahmos whereas all other competing subs will come with torpedo-fired Brahmos.

There's also the option of using a DRDO supplied AIP for the Russian sub, since that's really the only aspect we should be worried about. We are doing that already with the Scorpene. And it will likely be the case that the Russian sub will come primarily with Indian sensors and CMS, like the upgraded Kilos.

So it's not an easy choice.

Compared to the advantages of VLS, and the possibility of Indian AIP and sensors on the Russian sub, the French advantage is that the Scorpene is already in production in India and will come with an Indian AIP.

The 6th scorpene is 50% indigenised and as more production comes in, it will be fully indigenised. The advantage of being able to continue the manufacturing line and even expand it rapidly makes scorpene a much better option. Russian Amur class is not yet designed for Indian need and will take more development time.

What India gets from scorpene is ability to make fully indigenous submarine in India over short duration of time. India can then modify some design element to maintain stealth and upgrades once it gets hold of the process of making submarines.

We should really consider US asks, and must ask them to provide US submarine at Russian costs.

USA does not have diesel submarines. Even France sells diesel submarines to everyone but does not have it itself

The way procurement works in this country, as far as I understand, is that you need to simply meet the set technical requirements. If you meet them, you are shortlisted for the price bidding process where L1 and L2 are determined.

Whether you score any points over and above what the requirements call for has no effect on the shortlist or on the bidding process.

And AFAIK, the IN has no express intent to procure SSKs with VLS, it is not a requirement. So the fact that Russia offers an Amur model with VLS is not likely to get them placed any better with regard to the process. And as for VLS itself - it is unnecessary in my opinion. VLS only made sense if:

• The BrahMos-NG which can fit inside of 533mm torpedo tubes was not being developed.
• If the Nirbhay would not fit inside the same tubes.
• If IN had an outstanding requirement for sea-based land attack capability which no current or future surface combatants are capable of fulfilling.
• If we had not thought of converting the Arihant-class boats into SSGNs once the bigger SSBN class comes online and takes over deterrence patrols.

So there you have it - we don't need the VLS and the Russian sub is quite frankly inferior to Scorpene in most other parameters, including those that deal with reliability, life cycle cost, and allowing the customer to outfit customized equipment now or in future (where France is on par with Russians).

And one more thing - If France or UK with scope for global operations have no need of VLS on their attack subs, neither do we. Come to think about it, even the Russian Navy itself has no interest in procuring SSKs with VLS. The diesel subs which they used to attack targets in Syria fired Kalibrs from torpedo tubes.

Procuring additional Scorpenes (improved variants with MAREEM AIP, and incorporating Indian-made ASCMs and LACMs) makes every bit of sense, to me and to the IN from the looks of it. So if India buying Russian subs has US worried, I'd say they need not be cuz we're not buying any. Last one we bought was around 20 years ago and there doesn't seem to be any real scope for the future either.

Except of course the SSN leases, but technically that's not buying.

The most important part is that the next batch of scorpene will be the last one as P76 will be indigenous project based on the experience gained from P75 and P75I. VLS is not something that SSK will need. It is quite silly to make SSK armed with VLS. That will seriously harm operational ability. The diesel submarines are meant to be small submarines which are difficult to detect and do sneak attacks, not carry missiles!

So there you have it - we don't need the VLS and the Russian sub is quite frankly inferior to Scorpene in most other parameters, including those that deal with reliability, life cycle cost, and allowing the customer to outfit customized equipment now or in future (where France is on par with Russians).

And one more thing - If France or UK with scope for global operations have no need of VLS on their attack subs, neither do we. Come to think about it, even the Russian Navy itself has no interest in procuring SSKs with VLS. The diesel subs which they used to attack targets in Syria fired Kalibrs from torpedo tubes.

It's not a good idea at all to make PSUs take part in SPM contests, it defeats the entire purpose of the SPM. If the objective is to save money, then MDL must be chosen. And if the objective is to build capability for the future of the country, then MDL should not get the contract.

We will know what the IN wants once the RFP is out.

PSU or not, the existing infrastructure has to be maintained and that requires production. Capability build up in private sector by ruining capability of PSU is not reasonable

This is a problem for small navies in richer countries where labour is very expensive, not for us. We are not restricted by the number of types, so don't think of trying to save money for strategic systems, it's pointless to think of these things. Even as far back as the 90s, the IN always planned to operate 3 different SSKs.

And since we import, our operation prices will be very similar, regardless of how many types we operate. It doesn't matter to us if we buy 12 German engines or 6 German and 6 French engines, all 12 subs will come with pretty much the same offer price. And any savings by going for one supplier for all 12 will only benefit the supplier, not us. The supplier will give you a tiny discount for the bigger order and then shaft you later on, so you won't have any savings in the end. What we have been doing throughout our history has always been the smart move.

Very bad idea. Why should our new sub be a re-hash of what will be an obsolete submarine by 2030, whether it be the Barracuda or the Scorpene? The P-76 should reflect its time. By the time the P-76 begins construction, the Scorpene and Barracuda will be 30+ year-old designs.

The point here is that scorpene is planned to be indigenised, not kept on importing. So, why keep importing one type of submarines or other type instadof manufacturing scorpenes in India with some design changes using the available infrastructure? A submarine does not become obsolete just like that. Scorpene has seen lot of upgrades. Just like Ak47 is not obsolete, submarines don't go obsolete that quickly. Some indigenous upgrades can always be done

Imagine how much money could have been saved if we hadn't ever bought the Kilo and just license built more Type 209s. And make no mistake - the reason why we bought Kilos was Soviet pressure, and IN was forced to adjust their outlook accordingly. Same reason why IAF was forced to buy so many different types of MiGs instead of additional Mirages which is what they wanted.

Gross waste of capital. Sure this is according to plan...according to Soviet plan. Not our's. We get no advantage with such disparity in operating types - and especially when there is no difference with regard to the role being fulfilled by said types.

Russia was in deep problem and they gave India submarines at lower price and also helped India in many ways in technology. The MiG21 was not forced by Russia but they gave full technology to India and India made 657 in HAL as a cold war era ally. MiG29k was bought because that is the only plane that can take off from carrier. Mirages can't fly from carrier. Su30 from Russia also came with significant technology transfer.

The intent in getting imports must always be in getting technology to manufacture these items in the future within the country. In the case of submarines, scorpene already has 50% indigenous content and will go up in the next 3-6 submarines to even 100% after which some design modifications can be done to hide the stealth features from French (who in turn will tell all NATO allies) to avoid any problems from espionage or unnecessary weakness towards foreign countries

 

[Kvasir]

We want our new sub to move faster, farther and deeper, carry more etc, which is not all possible with existing designs.

Of course they're possible with existing designs. Just use newer materials when building new submarines, that allow them to dive deeper, not that that's even necessarily a good thing anyway (the deeper you dive the longer it takes to safely get back to the surface, changes in weapons and sensor performance as water temperatures change and topography alters, subs can already dive and operate deep, but operationally don't, etc.). A design is just a blueprint. They can always be revised.

Here's a question for you Randomradio, a basic question; how do you quiet a submarine? I'm not looking for generalities here, but specific design features.

es not have diesel submarines. Even France sells diesel submarines to everyone but does not have it itself

Not true entirely. The US doesn't operate DE or AIP submarines, yes, but they have designs. These designs are being upgraded frequently as newer technologies and tactics come online. While they don't use the designs themselves, or have shipyards with experience building DE or AIP subs, they do consulting work with foreign partners on submarine design, such as with Taiwan, Japan and Norway.

The designs aren't on paper strictly, there are a number of hull designs that have been tested at subscale.

Non-submarine designs too, to validate various signatures and the hull designs themselves.

The last DE submarine in service with the US was the Barbel class, though variants are still in service with the Netherlands and Taiwan

USS Blueback is well worth the tour if you ever find yourself in the US state of Oregon. It's moored at the OMSI museum.

 

[randomradio]

Of course they're possible with existing designs. Just use newer materials when building new submarines, that allow them to dive deeper, not that that's even necessarily a good thing anyway (the deeper you dive the longer it takes to safely get back to the surface, changes in weapons and sensor performance as water temperatures change and topography alters, subs can already dive and operate deep, but operationally don't, etc.). A design is just a blueprint. They can always be revised.

Um.... If you revise an existing design, with say, an extra plug for AIP, and then an extra plug for a VLS, and then an extra plug to carry more fuel, and then you upgrade the engine to lug all that weight, then you basically have a new class.

Here's a question for you Randomradio, a basic question; how do you quiet a submarine? I'm not looking for generalities here, but specific design features.

I know only the general stuff.

Say, all electric propulsion system, so that you can eliminate the reduction gearbox.
Sound dampners to absorb the vibrations from engines. You can have isolation materials running along the inside of the sub hull. You can place equipment on rubber mats. Join pipes using flexible materials. Anechoic rubber tiles on the outside to absorb sonar generated sounds.
Scewback propellers on most SSKs. Pumpjet on bigger subs which can generate more electricity.
Deperm to remove the hull's permanent magnetic signature by wrapping it with solenoid coils and isolating it. And then, continuous degaussing with a counteracting magnetic field to reduce external magnetic influence using onboard electro-magnets while the sub is in operation.
Low noise lighting for use inside the subs.
Better production techniques so that gears and other moving parts connect more seamlessly.

Then basic tactics:
Move slowly.
Crew being more discrete.
Stay below the thermal layer, at least in warmer regions.
The deeper you go, the less cavitation from propellers.

Although I don't get the point of raising this. It has nothing to do with the discussion.

 

[randomradio]

The 6th scorpene is 50% indigenised and as more production comes in, it will be fully indigenised. The advantage of being able to continue the manufacturing line and even expand it rapidly makes scorpene a much better option. Russian Amur class is not yet designed for Indian need and will take more development time.

What India gets from scorpene is ability to make fully indigenous submarine in India over short duration of time. India can then modify some design element to maintain stealth and upgrades once it gets hold of the process of making submarines.

How does that help in setting up a second production line?

Just buy 3 more Scorpenes and then buy a new class of submarine with a new company.

 

[advaidhya]

How does that help in setting up a second production line?

Just buy 3 more Scorpenes and then buy a new class of submarine with a new company.

After 3-6 more scorpenes, India will try to get completely indigenous ones. The additional scorpenes are to gain further indigenisation to eventually get full capability towards indigenous manufacturing scorpenes. There will be some modifications to submarine signatures to avoid anyone else from detecting, including France who already have scorpene signatures. So, there will be no question of importing after that.

So, even if second production facility is set up, there is every reason to produce indigenous submarine rather than get new submarine like Amur with high import content. There is another drawback with imports - the key signatures of the submarines are known to the supplier and the supplier may tell that to other countries. So, we can't afford to have unnecessary imports and unnecessary security risks

 

[Proud_Indian]

Security Scan - Project 75: Scorpene Class Submarines

 

[Ashwin]

An L&T-Russian partnership

Embattled by the controversy over the procurement of 36 Rafale fighters from France, the defence ministry is initiating a slew of defence acquisitions, worth almost Rs 400,000 crore (Rs 4 trillion). These would take years to fructify, but would allow the Bharatiya Janata Party to claim while campaigning for elections that it was safeguarding India’s defence. These include the procurement of 110 fighter aircraft worth about 125,000 crore (Rs 1.25 trillion), 57 naval fighters worth 75,000 crore (Rs 750 billion), S-400 air defence systems worth Rs 40,000 crore (Rs 400 billion), artillery guns worth Rs 15,000 crore (Rs 150 billion), rifles worth Rs 10,000 crore (Rs 100 billion), warships worth Rs 35,000 crore (Rs 350 billion) and two naval helicopter purchases for an estimated 25,000 crore (Rs 250 billion). All these are, while urgently needed, potentially controversial. But there is low-hanging fruit: Project 75-I -- a Rs 40,000 crore (Rs 400 billion) purchase that is operationally vital, relatively non-controversial and which includes a sizeable component of “Make in India”. This involves building six submarines in the country, with an Indian vendor taking essential technology from a foreign original equipment manufacturer (OEM).

The tendering process has already begun. Global submarine OEMs were issued a “request for information” (RFI) in June 2017 and responses received in October. The navy chief has revealed that four global vendors had responded: Rosoboronexport from Russia, ThyssenKrupp Marine Systems (TKMS) from Germany, Kockums from Sweden, and Naval Group from France – which is already partnering Mazagon Dock Ltd, Mumbai (MDL) in building six Scorpene submarines in India. Japan’s Mitsubishi Heavy Industries was asked whether it would offer its vaunted Soryu-class submarine but, surprisingly, given Tokyo was willing to supply submarines to the Australian navy, declined to participate.To partner the four OEMs in the fray, the Navy has launched the process to select an Indian “strategic partner” (SP), which would, under the new SP model of procurement, receive technology from the OEMs to build the submarine in India. The procurement process involves selecting the right combination of OEM and SP, evaluating technical capability, technology on offer and the price quoted.

While Admiral Lanba breezily stated he was hopeful “we’ll be able to make progress on this case by the end of 2018”, he did not define “progress” and the complexity of this procurement seems likely to delay it interminably. Given India’s need to counter China’s growing presence in the Indian Ocean, many more submarines are urgently needed. China will soon operate 60 submarines and, with the Indian Navy down to barely 15 submarines, even the neglected Pakistan Navy poses a daunting submarine threat. India’s 30-year plan, made out in 1999, to build 24 submarines has so far yielded just one boat (submariners quaintly refer to their lethal vessels as “boats”) with five more in the pipeline. It is essential, therefore, to kick-start Project 75-I.

Instead of wasting another five years toing-and-froing on the procurement (a conservative time-frame, given the defence ministry’s contracting record), Indian interests demand that Project 75-I must be awarded immediately on “nomination” basis. The winners select themselves: Larsen & Toubro with Russia’s Rosoboronexport as the technology partner. The two must work together to build six Amur-class boats, driven by air independent propulsion (AIP) developed recently by the Defence R&D Organisation (DRDO). The defence ministry must mandate indigenous content of 50 per cent for the first boat and 60 per cent for subsequent vessels. Tight timelines must be laid down, with financial penalties for infringements.

It is essential to spell out the logic for this bold recommendation. First, the selection of a Russian partner would conform to India’s 30-year submarine plan, in which the Union cabinet has mandated that if the first six boats are of western origin, the second six be of eastern origin, with the last 12 of Indian design, incorporating the best of east and west. The Navy has had a positive experience with its Foxtrot-class and Kilo-class Russian submarines, and with the two nuclear-powered boats taken on lease. The Amur class, a vast improvement on the Kilo-class vessels the Navy currently uses, promises to continue the Russian tradition of sturdy, economical, relatively silent boats. Continuing with the Kilo-based logistics infrastructure would save money. Fitting the BrahMos cruise missile, which the Navy wants on Project 75-I submarines, would be far easier on a Russian boat. The Russian Navy is buying four Amur-class vessels under the Russian Armament State Programme for 2018-2025, with the builder, Admiralty Shipyard, having already built two prototypes as the Lada-class.

L&T selects itself even more forcefully. Amongst Indian private sector shipyards, it is the only one with both infrastructure and credentials to build a line of submarines. Its new Kathupalli Shipyard, near Chennai, compliments its Hazira facility in Gujarat. While building hulls and machinery for the Arihant-class nuclear submarines, L&T has accumulated extensive experience of working to Russian designs and with Russian metallurgy, both of which find a prominent place in our indigenous warship design and construction traditions. The DRDO-developed AIP system that is required to be integrated into Project 75-I submarines, has L&T as its principle integrator. A senior L&T engineer says the company already has 85 per cent of the technology needed for fabricating a Russian-designed boat for Project 75-I. Besides L&T, only the Pipavav Shipyard, belonging to Anil Ambani’s Reliance Naval and Engineering Ltd, has the infrastructure to build submarines, but its abysmal record of delivery – it is years late in delivering five naval offshore patrol vessels, a far more simple warship than a submarine – makes it a dubious choice. Further, the continuing political uproar over offset-related orders placed on Reliance Defence by Dassault after the Rafale deal would give the government pause.

The other contender is MDL, which is pitching strongly for Project 75-I, arguing that its experience gained while building six Scorpene submarines under Project 75 should not be wasted and a follow-up submarine construction order be urgently placed. Even if the public sector MDL were to be allowed to bid as an SP (the model is actually intended to bring the private sector into defence manufacture), it would be hard pressed to match L&T on price. MDL has the infrastructure, but would need to pay more for technology transfer. MDL has absorbed French manufacturing practices in the Scorpene programme, but building Russian is another game.

Further, MDL has submarine work aplenty even after delivering all six Scorpenes. The Navy’s four German-origin Shishumar-class submarines – which were commissioned between 1986-1994 and have completed 24-32 years of service – are overdue for their life cycle extension overhauls, which would take until 2030 to complete. At the same time, the Scorpene submarines are already becoming due for mid-life upgrades and for retrofitting the AIP system during the upgrade. The first boat, INS Kalvari, commissioned last year, will fall due for an upgrade in 2023, followed by the other five. With MDL having built both the Shishumar-class and the Kalvari-class, it would be logical to entrust it with their upgrades.

That leaves only the question: What would Washington, already riled over India’s purchase of the S-400 from Russia, have to say about an equally strategic submarine purchase from Moscow. Here the US has a weak case, given that it has steadfastly refused to share submarine technology with India. If threatened with sanctions under the Countering America’s Adversaries Through Sanctions Act, New Delhi has only to reply: Let us co-manufacture the Virginia class nuclear attack submarine instead, and we will drop the Amur immediately. After all, that is what defence partners do!

 

[BMD]

How did you guys send a rocket to Mars when you can't build your own submarines and fighter jets?

 

[Ashwin]

How did you guys send a rocket to Mars when you can't build your own submarines and fighter jets?

We make nuclear submarines chap.

How do you guys make submarines but can't build rockets to put small satellites?

https://twitter.com/x/status/1040248413412093952

 

[Arvind]

Off topic posts are moved here

A Little Banter - Thread

Thread reopened !!

Please discuss the subject P75 here only.

 

[BMD]

 

[Kvasir]

The only problem is that B-586 Kronshtadt isn't AIP equipped. Laid down 13 years ago, it was planned to be a cheap, small, Kilo-type submarine with air independent propulsion, but as of now its DE, not AIP.

B-586 will be assigned to the Baltic fleet where she'll be subjected to significant NATO and non-NATO anti-submarine countermeasures in what are relatively shallow waters.

She's to replace older Kilos assigned to the same fleet.

 

[Angel Eyes]

The only problem is that B-586 Kronshtadt isn't AIP equipped. Laid down 13 years ago, it was planned to be a cheap, small, Kilo-type submarine with air independent propulsion, but as of now its DE, not AIP.

B-586 will be assigned to the Baltic fleet where she'll be subjected to significant NATO and non-NATO anti-submarine countermeasures in what are relatively shallow waters.

She's to replace older Kilos assigned to the same fleet.

What do you think of Scorpenes...Are they any good??

 

[Kvasir]

What do you think of Scorpenes...Are they any good??

They're pretty darn good, comparing favorably with the Lada-class (AIP, not the current DE designs), Type 214 and S-20 (with the optional AIP module). Similar design (length, beam, draught), stern plane arrangement, tower design, torpedo tube numbers, propulsion type. Nothing that sets them apart, though their really, really quiet owing a lot to their internal systems and stores mounting arrangement (rafting), but they're among the best submarines around today.

I had a chance to review their design during contract negotiations between the French and Norwegian governments, as we'd (meaning me) would have major contracting work on any potential Type 210 replacement and found them to be a great option, though ultimately we decided to go another route. There are two problems I found with the Scorpene during the design review, and keep in mind the actual results are classified, sorry, so you're only getting generalities from me based on my assessment during review.

1. The Type 212A is simply a superior design when it comes to signature suppression and maneuverability at slow speed, which is ideal for an DE or AIP design. More hydro-dynamically streamlined, X-stern plane versus cruciform allowing for superior shallow water maneuverability, non-magnetic hull and interior machinery, quieter.

1a. Where the Scorpene came out ahead was in endurance, range and diving depth, duration and frequency, and the AIP design, which is more reliable and less dangerous versus fuel-cells. It's also very reliable and has quick turn around during maintenance, owing to high levels of automation, allowing for more days at sea and carries a tad more torpedoes, mines or missiles, which is nice. Scorpene is basically a small SSN hull (in terms of materials used, shaping, etc.)

2. France is a crappy partner to work with.

Other then that the Scropene are pretty much the best around today.

I can't wait to get my hands on the A26.

...

*I should add that the Type 212 I reviewed isn't the Type 212A of today but a submarine design called Type 212CD (common design), formerly known as Type 212NG (next generation/Norway-Germany). I used the Type 212A as a comparison owing to the classified nature of Type 212CD design elements. Sorry, but not even breadcrumbs about its design. I've got work to do on the Type 212CD so my lips are shut.

 

[randomradio]

They're pretty darn good, comparing favorably with the Lada-class (AIP, not the current DE designs), Type 214 and S-20 (with the optional AIP module). Similar design (length, beam, draught), stern plane arrangement, tower design, torpedo tube numbers, propulsion type. Nothing that sets them apart, though their really, really quiet owing a lot to their internal systems and stores mounting arrangement (rafting), but they're among the best submarines around today.

I had a chance to review their design during contract negotiations between the French and Norwegian governments, as we'd (meaning me) would have major contracting work on any potential Type 210 replacement and found them to be a great option, though ultimately we decided to go another route. There are two problems I found with the Scorpene during the design review, and keep in mind the actual results are classified, sorry, so you're only getting generalities from me based on my assessment during review.

1. The Type 212A is simply a superior design when it comes to signature suppression and maneuverability at slow speed, which is ideal for an DE or AIP design. More hydro-dynamically streamlined, X-stern plane versus cruciform allowing for superior shallow water maneuverability, non-magnetic hull and interior machinery, quieter.

1a. Where the Scorpene came out ahead was in endurance, range and diving depth, duration and frequency, and the AIP design, which is more reliable and less dangerous versus fuel-cells. It's also very reliable and has quick turn around during maintenance, owing to high levels of automation, allowing for more days at sea and carries a tad more torpedoes, mines or missiles, which is nice. Scorpene is basically a small SSN hull (in terms of materials used, shaping, etc.)

2. France is a crappy partner to work with.

Other then that the Scropene are pretty much the best around today.

I can't wait to get my hands on the A26.

...

*I should add that the Type 212 I reviewed isn't the Type 212A of today but a submarine design called Type 212CD (common design), formerly known as Type 212NG (next generation/Norway-Germany). I used the Type 212A as a comparison owing to the classified nature of Type 212CD design elements. Sorry, but not even breadcrumbs about its design. I've got work to do on the Type 212CD so my lips are shut.

The likely options for us seem to be larger versions of the Scorpene, Type 214, A26 and a Russian sub (likely Project Kalina).

 

[Angel Eyes]

Thanks for sharing your insights...
So, scorpene data that was leaked last year, could it compromise the submarines?.
Assuming it could compromise the submarine, is there any way to alter the design of submarine internally so that data that was leaked would be useless?

They're pretty darn good, comparing favorably with the Lada-class (AIP, not the current DE designs), Type 214 and S-20 (with the optional AIP module). Similar design (length, beam, draught), stern plane arrangement, tower design, torpedo tube numbers, propulsion type. Nothing that sets them apart, though their really, really quiet owing a lot to their internal systems and stores mounting arrangement (rafting), but they're among the best submarines around today.

I had a chance to review their design during contract negotiations between the French and Norwegian governments, as we'd (meaning me) would have major contracting work on any potential Type 210 replacement and found them to be a great option, though ultimately we decided to go another route. There are two problems I found with the Scorpene during the design review, and keep in mind the actual results are classified, sorry, so you're only getting generalities from me based on my assessment during review.

1. The Type 212A is simply a superior design when it comes to signature suppression and maneuverability at slow speed, which is ideal for an DE or AIP design. More hydro-dynamically streamlined, X-stern plane versus cruciform allowing for superior shallow water maneuverability, non-magnetic hull and interior machinery, quieter.

1a. Where the Scorpene came out ahead was in endurance, range and diving depth, duration and frequency, and the AIP design, which is more reliable and less dangerous versus fuel-cells. It's also very reliable and has quick turn around during maintenance, owing to high levels of automation, allowing for more days at sea and carries a tad more torpedoes, mines or missiles, which is nice. Scorpene is basically a small SSN hull (in terms of materials used, shaping, etc.)

2. France is a crappy partner to work with.

Other then that the Scropene are pretty much the best around today.

I can't wait to get my hands on the A26.

...

*I should add that the Type 212 I reviewed isn't the Type 212A of today but a submarine design called Type 212CD (common design), formerly known as Type 212NG (next generation/Norway-Germany). I used the Type 212A as a comparison owing to the classified nature of Type 212CD design elements. Sorry, but not even breadcrumbs about its design. I've got work to do on the Type 212CD so my lips are shut.

 

[Bon Plan]

France is a crappy partner to work with.

??? why?

 

[Kvasir]

??? why?

There's a reason the tender for a Type 210 replacement was cancelled and exclusive government-to-government negotiations with Germany were established - France is too inflexible. Unwilling to meet our requirements for joint development. Unwilling to meet our requirements for joint production. Unwilling to meet our requirement for alternative subsystems. France offered the Scorpene and basically said "take it or leave it". We left it due to their inflexibility.

So, scorpene data that was leaked last year, could it compromise the submarines?.

No. The info leaked - internal rafting arrangement, propeller design, performance, acoustic dampening means, etc. - it's all bad to have leaked, but it's not damning to the submarine. And why? Because these data points aren't static. Noise generation, frequency and harmonics are unique to a given submarine and only known after the submarine hits water, and stored locally in the submarine's Ship Data Book, not on a corporate power point.

Shown here is a baseline acoustic signature test. The noise levels of the submarine will change at different thermocline grades will at sea as sonar and sound travel differently through alternate thermal layers.

Likewise noise levels will change based on speed. Not just because machinery gets louder the faster the boat goes, but due to increased cavitation, which as the bubbled produced pop, gives of a highly noticeable sound signature.

Knowing the frequency of the submarine's sonar or electronic signals gathering equipment isn't helpful either, since these are mainly passive. A submarine can use active sonar, but that betrays their position to anyone with a hydrophone really quickly. In 30 years of service with the Norwegian Navy, the number of instances where a Type 210 has used active sonar are in the single digits.

Submarine range, endurance at sea and diving depth are all pretty much public domain and anyone with Google or Wikipedia could find that. No big intelligence coup here.

Info on the combat management system could give away interesting tidbits, such as what loadout the submarine will operate with and what sensors they have to support them, but again, it's nothing special as far as data points go.

The data leak shows corporate baselines, not specifics to individual submarines. It's general info which is still bad to have leaked, but nothing damning to a Scorpene fleet.

Assuming it could compromise the submarine, is there any way to alter the design of submarine internally so that data that was leaked would be useless?

Sure. As I recall India is putting its own indigenously developed AIP design on the P-75 class submarines, so that in of itself would invalidate many noise metrics. A new propeller could easily be designed, another sonar chosen, a different combat management system added or the current one coded differently.

Most of the data can be counteracted through superior helmsmanship though, which is where a submarine gains its advantage anyway. Knowing the topography, where the thermal layers are, ocean depth and current. That's all more important then a submarines own signatures because once at sea they'll be making the more impact.

 

[Angel Eyes]

As I recall India is putting its own indigenously developed AIP design on the P-75 class submarines,

Yes , we will be retrofitting them with DRDO developed phosphoric acid based fuel cells