Project-75I class SSK Submarines

[Gessler]

Seems that inclusion of Lithium-Ion Batteries (LIB) technology is going to be a mandatory requirement under P-75I, alongside AIP.

https://mazagondock.in/images/pdf/investor-update-call-transcript-29062021.pdf

 

[Covfefe]

Seems that inclusion of Lithium-Ion Batteries (LIB) technology is going to be a mandatory requirement under P-75I, alongside AIP.

View attachment 114811

https://mazagondock.in/images/pdf/investor-update-call-transcript-29062021.pdf

Navy tilting towards Korean KSS? Proven AIP, Li-ion batteries, VLS tubes

 

[Gessler]

Navy tilting towards Korean KSS? Proven AIP, Li-ion batteries, VLS tubes

VLS not a requirement - in fact the version of KSS that's being offered in P75I will not have any VLS according to the Koreans:

MADEX 2021: DSME Sheds Light on Submarine Offer to India for P-75I - Naval News

At MADEX 2021, the naval defense exhibition held in Busan last week, local shipbuilder Daewoo Shipbuilding and Marine Engineering (DSME) was pitching its 3,300 ton (surface displacement) submarine, dubbed the DSME 3000, to India for the country’s Project 75I-class (P75I) programme.

www.navalnews.com

The AIP & LIB packages will have to be comparatively evaluated. Not impossible for the others to come up with LIB packages via some sort of sub-contract to another company, even from another country. What will ultimately matter is the reliability, power density & price of the package they offer.

Same goes for AIP. Doesn't matter if its already in use or not.

 

[MonaLazy]

version of KSS that's being offered in P75I will not have any VLS

That's a June 2021 article from naval news. There is a more recent one from 3 days ago:

The 4 Submarines Competing For The Indian Navy's P-75I Program - Naval News

The Indian Navy's P-75I submarines will be larger and much more potent than the Kalvari Class now entering service. They will be the bedrock of India's submarine fleet at a time when the strategic focus is leaning towards China as well as the traditional adversary, Pakistan. There are 4 contenders.

www.navalnews.com

Specifically on the DSME-3000

DSME-3000, South Korea’s Missile Submarine
South Korea has recently spread its wings and entered the submarine export game, selling boats to Indonesia. They are understood to be proposing an export version of their home-grown KSS-III design. This is a relatively large non-nuclear boat, likely second only to the Barracuda.

The type comes with German based fuel-cell AIP. The layout, with a hull section essentially dedicated to AIP, suggests that it would not be too challenging to swap it for the Indian alternative.

And South Korea is ahead of most countries in the race to fit lithium-base battery technology to submarines. This promises to extend the endurance of submarines when running on batterie. Naturally this may be attractive to the Indian Navy, even potentially diminishing the importance of AIP.

Its differentiating feature is that it already comes with a six or ten round VLS. In South Korean service this is expected to carry the Hyunmoo 4-4 missile, which is roughly equivalent to India’s K-15 Sagarika but without a nuclear option. While exact dimensions and weights are not available, this at least implies that it could accommodate the similarly sized Brahmos.

Carrying a VLS in such a small submarine likely needs some trade-offs, like fewer weapons slots in the regular torpedo room. But overall the South Korean design seems balanced and highly capable.

Please see this post also:

Project-75I class SSK Submarines

Govt issues formal tender for 6 submarines under strategic partnership model Along pending project of the Indian Navy for building of indigenous submarines is finally set to kick off as the Ministry of Defence has issued Request for Proposal (RFP) for its mega submarine programme. The RFP...

defenceforumindia.com

The above infographic does show a Brahmos ejecting from the VLS!

 

[Gessler]

That's a June 2021 article from naval news. There is a more recent one from 3 days ago:

The 4 Submarines Competing For The Indian Navy's P-75I Program - Naval News

The Indian Navy's P-75I submarines will be larger and much more potent than the Kalvari Class now entering service. They will be the bedrock of India's submarine fleet at a time when the strategic focus is leaning towards China as well as the traditional adversary, Pakistan. There are 4 contenders.

www.navalnews.com

Specifically on the DSME-3000





Please see this post also:

Project-75I class SSK Submarines

Govt issues formal tender for 6 submarines under strategic partnership model Along pending project of the Indian Navy for building of indigenous submarines is finally set to kick off as the Ministry of Defence has issued Request for Proposal (RFP) for its mega submarine programme. The RFP...

defenceforumindia.com

View attachment 114950

View attachment 114951

The above infographic does show a Brahmos ejecting from the VLS!

That is interpretation of HI Sutton.

The VLS requirement is not mentioned anywhere. Show me a single official document requiring it?

There's no indication that this was added in the RFP (which is only available for SP/OEMs btw, so HI Sutton couldn't have seen it even if it was) either.

 

[Covfefe]

@MonaLazy @Gessler
Wouldn't the availability of VLS make it more attractive for the IN? Something like the twin engine option for IA's LUH. And do we have any of our own horizontally launched cruise missile?

Also for the AIP issue, wasn't the DRDO AIP rejected due to lack of a proof of concept on a working platform, leaving behind only two suppliers in the competition- German ThyssenKrup and Korean Daewoo? (The German company pulled out later due to ToT and localisation demands)

 

[Gessler]

@MonaLazy @Gessler
Wouldn't the availability of VLS make it more attractive for the IN? Something like the twin engine option for IA's LUH. And do we have any of our own horizontally launched cruise missile?

The way Indian procurement system works - you meet the requirement, you get full marks. You don't meet the requirement, you get zero marks. Going above & beyond the requirement does not give you any extra marks.

Unless required, nobody will offer VLS because adding another module will increase cost, and make their offer less competitive in the cost negotiations, potentially losing out the contract.

Also for the AIP issue, wasn't the DRDO AIP rejected due to lack of a proof of concept on a working platform, leaving behind only two suppliers in the competition- German ThyssenKrup and Korean Daewoo? (The German company pulled out later due to ToT and localisation demands)

The DRDO AIP was never really meant for P-75I, but only for Scorpene refit. The intention was that the AIP could be ready by the time INS Kalvari comes in for its first major refit. I don't know for sure when that is scheduled.

I have heard something to the effect of having to be Operational-at-Sea, but we'll see what transpires. We aren't anywhere close to selecting an offer yet. That will only happen by around ~2025 or later.

Who knows how many changes could be introduced by then. Or even scrapping the whole thing and going back to square one. Wouldn't be the first time we did that in a deal of this scale.

 

[MonaLazy]

A detailed look at Ozzie submarine experience starting with the Oberon class to Collins, the SEA-1000 cancellation & finally AUKUS.


Notables:

1. Australia's first class of submarines the O boats were maintenance intensive - complete refit every 5 years- huge manhours, sustainment costs (manufactured and supported from UK)
2. Essentially rebuild the submarine on every docking- crippling cost and availability by having to rely on foreign suppliers
3. Why local manufacture for Collins class? Over and above the jobs from local manufacture of subs sustainment becomes easier- so direct imports are a strict no-no even with lower upfront costs
4. Indiscretion rate- How often a DE (diesel-electric) submarine has to surface and recharge its batteries. DE subs spend a majority of their time running off electric propulsion- inherently quiet making the sub stealthy but batteries hold charge only for so long. As they are depleted the sub has to snorkel- putting its tube above the water & running diesel engines to recharge the batteries. Very visible & vulnerable time for the sub as the diesel engine is loud making it much less discreet and the sub has to remain at periscope depth. Over 4 hours for the Oberon class if the batteries were dead flat.
5. Ideally, a sub must stay submerged longer and recharge its batteries faster
6. Australian subs need to transit 6000 kms just to reach their patrol area in Andaman Sea, South China sea and Philippine sea- typically a job for larger subs with nuclear propulsion. So DE was an odd choice as they are small short-range vessels that are designed to be operated in a nations near seas.
7. Endurance of the crew- less crew in more space is always better
8. What made the Collins class unique was its size- 3500 tonnes. During its design period it was among the largest conventional subs ever made- substantially greater displacement than the Russian Kilo
   1. Increased internal volume which helped with endurance and indiscretion rate
   2. 50% greater displacement allowed a far larger number of batteries to be installed greatly improving the Collins submerged endurance- 3 or 4 days between snorkelling if the boat is being frugal
   3. The submerged performance of the Collins is over 4x greater than its predecessor the Oberon simply because of its volume and the size of its battery bank
   4. The boat's size allowed for much larger diesel generators- 4,2 MW electricity generation capacity allowing her to rapidly recharge batteries- again a 4x improvement over the Oberons
   5. Going at speed the Collins can recharge its batteries from depletion to full charge in 1 hour
   6. During initial sea trials HMAS Collins demonstrated that under typical patrol conditions when the boat was moving slowly & conserving energy she was able to run an energy cycle that required her to snorkel for just a couple of minutes every 24 hours
   7. In mid-1990s DSTO tested 2 AIP technologies one of which was the Sterling system used today by Kockums however the submerged performance of the Collins class was so good that these were immediately dropped- space, weight & cost penalty for oxidizer tanks etc did not offer a marked improvement over the baseline capability
   8. Capt Paul Greenfield of RAN remarked- "Sea trials of the first-of-class have proven that the Collins as it is now can stay submerged for such a long time, and have such a low rate of indiscretion, that a refit of an AIP system is not really needed and would simply have no cost-benefit."
   9. By building a boat as large as Collins and focussing the design around submerged endurance Oz had been able to produce a sub that had such a low indiscretion rate that AIP was not worth the installation
   10. By mid-2010s completely sustained by an Australian supply chain - for much higher availability and much lower sustainment costs than the Oberons. No more month-long delays waiting for international part suppliers during refits
   11. Capable of 90-day patrols remaining on station for 7 weeks at a range of 2500 nm and giving them submerged performance so good that contemporary AIP systems were simply not worth utilizing
   12. American BYG1 combat system + large and advanced sonar suite + Mk 48 torpedo gave the Collins a level of lethality and combat effectiveness that approached nuke subs- in their ability to detect, track and classify and engage stealthy targets
9. Interesting to note that the French offered the nuclear barracuda to the Australians in 2015-16 but the Ozzies themselves rejected nuclear propulsion because it was not viable-
   1. Only LEU tech was on offer which required refuelling every 10 years- which is complicated as you have to complete the nuclear fuel cycle- Oz has no civilian nuke industry so the costs of establishing & running enrichment, conversion, fuel manufacture and spent fuel handling and storage just for the nuke subs are so high that it was never a realistic option
   2. Even if the fuel is imported Oz does not have the specialized infra and personnel to handle spent fuel- further increasing cost
   3. Having another nation refuel Oz subs posed unacceptable vulnerabilities - there is no guarantee Franco-Australian relations would be good for 50 years. Paris could refuse to refuel Ozzie barracudas if there was a conflict of interest- rendering them impotent. Even the threat of ceasing such support gives France immense leverage over Australia. Risk for sovereignty.
   4. Extremely poor submarine availability sailing them to France for full-cycle docking
10. 4200 tonne Soryu Class
    1. Details are sketchy but in range and endurance Soryu is worse than the barracuda and Collins both
    2. The first 10 platforms were equipped with an AIP system (4x Kockums sterling engines) in addition to a DE system for a submerged endurance of 6000 nm without surfacing- very close to a nuke sub
    3. AIP systems require large oxidizer tanks which eat up space for batteries and fuel- significantly lower patrol range despite being larger than Collins
    4. Penalty on internal space for the crew- crew amenities are inferior to the Collins class
    5. The final two boats in the Soryu class use a diff propulsion layout beginning with Oryu the AIP system has been completely removed- Only diesel generators and Li-Ion batteries- significant improvement in performance over lead acid systems providing a level of energy density that essentially makes AIP redundant
    6. Onboard electricity generation capacity is 70% of Collins- so Collins can recharge her batteries faster
    7. Serious concerns about the safety of Li-Ion batteries in subs- in 2008 a Li-Ion equipped mini sub exploded and was completely destroyed- will be total loss of vessel at depth
    8. Japanese only require a 20 year life in their subs rather than the 30+ by RAN- has implications o the design from the grade of steel used to the quality of the welds
    9. Japanese consortium has no experience of constructing a vessel internationally
    10. Highly problematic option because of above reasons
    11. A former sub engineer Paul Greenfield noted- "Australia's future sub would require over 100,000 cells in some 500 modules and the life of 100,000 cells & a fleet of 12 subs- there is likely to be a failure that cannot be stopped or controlled with a catastrophic outcome."
11. 4300 tonne Type 216 - essentially an enlarged Type 212 in service with Germany & Italy
    1. Good on paper but the largest sub TKMS ever produced was the 2200 tonne Dolphin class for Israel. This was to be the largest sub they had ever designed or manufactured. Brand new platform- Risk!
    2. Hybrid DE and AIP (methanol + liquid oxygen to drive a hydrogen fuel) could remain submerged for 2600 nm at 4 knots
    3. Equiped with Li-Ion batteries the DE drive gave the boat an additional 10400 nm range
    4. Indescretion rate 20%
    5. TKMS had to scale up the Type 212 to more than double it's size
12. 5000 tonne Conventional barracuda (Short-fin Barracuda block 1A)
    1. Proven hull design of the Suffren, but use DE propulsion- required a complete redesign of the sub as all the internal spaces had to be modified
    2. No AIP, No Li-Ion but lead-acid batteries. But these were clearly not critical technologies for RAN. A large enough battery bank combined with a large enough electricity generation capacity can make the indiscretion rate so small that the advantage of AIP systems is minimal in real-world operations- How important is your ability to avoid snorkelling when this only takes a few minutes every 24 hours. Is it worth the substantial penalties you pay in range and endurance?
    3. By having a larger submarine and keeping the propulsion conventional the design had a massive range 18000 nm
    4. Generous crew amenities increasing effective endurance
    5. only design equipped with a pump jet instead of a propeller- higher top speed and a higher speed without cavitation
    6. 28 weapons on board for max fire power
    7. Tech challenge of converting nuke design to conventional remained substantial

SEA-1000 proposal- features like AIP, Li-Ion batteries, pump jet propulsion were not mandatory

For the Collins class even with old fashioned lead-acid batteries the size of the submarine alone provides substantial advantages in submerged performance if the indiscretion rate is prioritized. Li-Ion batteries can always be retrofitted at a later time when the risks were better understood. Safety concerns is why NG (Naval Group) chose lead-acid batteries. Short fin barracuda had the best range, endurance, kinematic performance and firepower. It would also be manufactured in Australia. One of the largest conventional subs ever built like the Collins for substantial performance advantages.

This still born attack class sub had the potential to be the most lethal and capable conventional sub ever created. The brains of a Virginia class SSN in a sleek and stealthy French body driven close to the speed of a nuke sub via pump jet propulsion but then why did the attack class program flounder?

Short answer: The deteriorating Sino-Australian relationship & the American decision to transfer nuke reactors to Australia.
Long answer:
Substantial advantages of nuclear propulsion which RAN prioritized as operational requirements. Chinese satellite intelligence is increasingly getting stronger. The Yaogan satellite constellation contains 30+ active EO imaging and SAR systems arranged in a staggered series of polar orbits. These sats make passes over the Western Pacific every hour or so playing a key part in PLA's wide area ocean surveillance system in their A2AD complex. They will pose a threat to any hostile (to China) sub operating near the surface- makes DE subs vulnerable to detection while they are snorkelling. In the wide open areas Ithe Pacific or Indian oceans it is not critical as by the time a Chinese asset is in the area the sub would have vanished but in heavily defended areas like SCS this will be an increasingly dangerous vulnerability- even AIP will not fundamentally address this issue. A nuke sub can stay deep throughout its entire 90 day patrol when an AIP sub would still have to regularly snorkel. The indiscretion rate for a nuke sub is 0.

From a legal angle:
The NG was never given a contract to build 12 subs! The contracts were structures in a way that they progressed from one stage to the next. SPA (strategic partnering agreement) was the framework for issuing actual contracts in various stages. Only once one program contract was completed would the next be issued to NG. Allowed the Ozzie Gov to keep its options open providing several off ramps if they no longer wanted to proceed for any reason. No guarantee that the govt would move to the next phase once one phase was over.

One of the other major advantages nuclear propulsion provides a submarine is the colossal amount of electricity a nuke reactor produces- 10x or more a DE sub, called the hotel electric power this is the spare electricity a sub has to use other than to move the vessel- sonars, computers. fridges, lights. In a conventional sub everything runs off the battery bank- it impacts submerged endurance. New systems of sub warfare will need more and more electric power. USN is developing a high energy laser for the Virginia class sub fired from the photonics mask what used to be a periscope this laser will be able to target drones and anti sub helis, to support underwater drone ops. In the very near future, a single sub may act as the mothership to a fleet of drones that will act as the boat's eyes and ears extending its sense of footprint dramatically- these will all require electrical power.

Australia needs bigger, more powerful boats than the attack class. Astute displaces 3000 tonnes more while surfaced while Block 5 Virginia is 2x the size of the attack class- carry more weapons, can steam faster, transit greater distances much more quickly and therefore remain on station longer. Pump jet equipped HMAS Attack could have reached 20+ knots top speed but doing so would have rapidly drained its batteries while a Virginia or Astute can steam at 30+ knots indefinitely. Both vessels have room for at least 10 additional weapons- more credible land attack capability.

Why were these advantages of nuke subs not realised in 2016 when the attack class was selected?
Canberra and Beijing relations have nose dived only recently and little hope of reversing trend. The problem of the nuclear fuel cycle from 2015-6 is now addressed by AUKUS. The reactor will arrive in a sealed steel box made in US (or UK) ready to be installed in the sub, it does not need to be refuelled until the sub is de-commissioned (single largest cost of operating a nuke sub). GE developed a HEU fuelled SG-9 reactor with a life of 33 years- the core will remain sealed throughout it's entire operational life. No Oz personnel will have to handle HEU fuel ever. After the life of the sub the still sealed box of the reactor will be transported to the US for disposal. With the American reactor tech Australia does not need to have a nuclear fuel cycle in order to have a nuclear submarine. Sits well with the NNPT as, under article 3, the use of fissile material for military reactor fuel by non-nuclear weapon states is not prohibited.


Fuel cycle:

Based on this understanding what are the implications for choices being made in P75I?

Ozzie experience clearly shows a large bank of lead-acid batteries with powerful diesel generators can be more effective than AIP. AIP provides close to nuke sub submerged range but comes at the cost of patrol range and crew comfort. Is IN simply suffering from brochuritis to be harping on AIP? I think not. They are targeting P-75I for defensive ops and are maximizing stealth (against an intruding Chinese sub) via long submerged operations close to India's shores while SSNs will go up to SCS and be the offensive arm of IN. Also longer submerged endurance will keep INs DE subs hidden from Chinese satellites.

The possibly explosive Li-Ion batteries are de-risked to some extent by insisting on it being operational in a submarine & the higher power density will also add to submerged endurance in a very compact form factor again aiding stealth. P75I could provide an exceptionally low indiscretion rate with the quietness of DE propulsion. However, a couple of questions remain:

1. At 20+ knots top speed & draining batteries fast while being chased they will not be able to outrun 30+ knots with unlimited endurance Chinese SSNs (even if noisier reactor & badly cavitating)- only relying on stealth to save the day but no recourse other than weapons once the cover is blown. How wise a choice is that?

2. With the mothership concept of operations how will a DE sub provide electricity for all collaborating manned/unmanned vessels & laser weapons? Is it future proof from a power generation point of view? The recent USS Connecticut collision with probably a Chinese XLUUV is only an indicator of a continually increasing threat of under sea drones.

 

[MonaLazy]

The first 10 platforms were equipped with an AIP system (4x Kockums sterling engines) in addition to a DE system for a submerged endurance of 6000 nm without surfacing- very close to a nuke sub

1. AIP systems require large oxidizer tanks which eat up space for batteries and fuel- significantly lower patrol range despite being larger than Collins
2. Penalty on internal space for the crew- crew amenities are inferior to the Collins class
3. The final two boats in the Soryu class use a diff propulsion layout beginning with Oryu the AIP system has been completely removed- Only diesel generators and Li-Ion batteries- significant improvement in performance over lead acid systems providing a level of energy density that essentially makes AIP redundant

This Japanese choice of removing AIP & sticking with only diesel generators & long-lasting Li-Ion batteries (LIBs) carries on to the next-generation 29SS class submarines


Maybe something IN should consider in light of point 1 above.

NMRLs PAFC also requires large oxidiser tanks reducing space for fuel & LIBs.

The Naval Materials Research Laboratory of Indian Defence Research and Development Organisation in collaboration with Larsen & Toubro and Thermax has developed a 270 kilowatt phosphoric acid fuel cell (PAFC) to power the Kalvari-class submarines, which are based on the Scorpène design. All six Kalvari class submarines will be retrofitted with AIP during their first upgrade. It produces electricity by reacting with hydrogen generated from sodium borohydride and stored oxygen with phosphoric acid acting as an electrolyte

Air-independent propulsion - Wikipedia

en.wikipedia.org

Features of 29SS worth copying:
- X shaped rudders
- inclined bow & conning tower squashed downward blending into hull
- diving planes moved from sail to front of hull (like Astute class)
- pump jet propulsor
- conformal sonar systems

improved aqua dynamics, stealth, lower drag resulting in increased speed and range

 

[swapcv]

Features of 29SS worth copying:
- diving planes moved from sail to front of hull (like Astute class)

You sure? Looks like still on the sail for now.

 

[MonaLazy]

You sure? Looks like still on the sail for now.

Yes! It was revealed by submarine manufacturer Mitsubishi Heavy Industries only in June 2019 via a presentation & will begin development only in 2025-28, and is targeted for entry into service in 2031. Finding a photograph of the real sub is an impossibility at this point.

Translation- New submarine concept model for Mitsubishi Heavy Industries JMSDF

As the next-generation submarine of 29SS, the integrated control system adopted in 30FFM is adopted for the submarine.
All the information was collected on one large monitor inside the ship, and labor saving was taken into consideration.
A new concept submarine that is completely different from conventional submarines.

H I Sutton - Covert Shores

Further reading-

Meet the 29SS: Japan's New Stealth Submarine

Watch out China.

nationalinterest.org

The 29SS appears to be a further evolution of the LIB-powered Soryu, retaining its same essential hull form and its X-shaped rudder, which improves maneuverability and resilience. However, the Soryu’s bow has been inclined and its tall sail (conning tower) squashed downwards and blended into the hull of the 29SS. Diving planes formerly located on the sail are moved to the front of the hull.

These modifications appear intended to improve aquadynamics, thus enhancing acoustic stealth and decreasing drag, which could result in increased speed and range. A “floating floor structure that can mitigate vibrations and shocks” may also make the 29SS quieter.

The 29SS’s shrouded propulsion system configuration suggests a heavier pump jet propulsor system instead of a conventional propeller. Pump-jets are unlikely to produce noisy cavitation, and allow quieter running at higher speeds. One source claims a “thirteen-blade” pump-jet would be 20 decibels (two orders of magnitude) quieter than the seven-bladed propeller on the Soryu. The incorporation of pump jets suggests the 29SS may be designed to cruise at higher speeds for longer than is typical of a diesel-engine submarine.

The 29SS’s bow sonar will reportedly be optimized for discretion, long-distance detection, and also function better in shallow coastal waters. This last is particularly a concern in the rocky shallows off the Korean peninsula, in which North Korea operates dozens of small submarines that could prove difficult to detect.

The 29SS’s side-array hydrophones will reportedly use a fiber optic sonar which “senses sound not by the pressure of sound waves but by the interference effect of light.” This sensor may also be effective for detecting electromagnetic emissions.

There will also be a towed sonar array for long-distance, omnidirectional tracking, a reverse-search sonar array, and a broadband transmission array.

Returns from multiple sonars will reportedly be integrated into a synthetic sensor picture on the submarine’s new combat system, which can perform target-motion analysis and suggest firing solutions.

So far, there’s no evidence the 29SS includes vertical launch cells for missiles. While submarines can deploy missiles like the UGM-84 Harpoon out of their torpedo tubes, vertical cells allow ripple-fired salvoes that are more likely to overwhelm a target’s air defenses.

Here's the part I'm most interested in:
Propulsion: Lithium-Ion Batteries, New Diesel Engines and “High Power Snorkels”

The SS-29 class will be built around the extraordinary battery capacity offered by lithium ion batteries (LIB). At the blog Submarine Matters, analyst Peter Coates speculates the new design might boast up to ten days cruising submerged.

However, ditching the Stirling air-independent propulsion system used in earlier Soryu boats involves a tradeoff.

LIBs may allow a submarine captain more flexibility in aggressively using battery power—and a submarine running purely on battery with its diesels off can be quieter than a nuclear powered-submarine.

But once a LIB-only sub exhausts its battery, it must surface or use its snorkel to suck in more air to run its diesel engines—during which time it will be much more vulnerable to attack. By contrast, AIP-equipped submarines can sustainably run for a few weeks confined to low speeds before surfacing, and nuclear-powered boats can operate underwater indefinitely even at high speeds.

As Japanese submarines are likely to go on patrols closer to port, this tradeoff may be deemed acceptable. Still, the 29SS will incorporate technologies designed to minimize the length of “indiscretion” time at or near the surface, including a “more compact, quiet and powerful” “Snorkel Power-Generating System” which presumably will allow the submarine to snort air and generate electricity more efficiently.

Japan has already studied optimizing the snorkel for the diesel engines on the Soryu class. Though LIBs are faster charging, given the SS-29’s huge planned battery capacity, the improved snorkel may be necessary to avoid taking longer than the claimed 100-minute charging time for the LIB-equipped Soryu.

Technically, LIBs could be combined with the AIP system, and indeed Japan reportedly studied possibly developing a Fuel-cell AIP, which is quieter and enables longer endurance than the Stirling AIP on the Soryu. However, the Japanese defense ministry decided this would be excessively expensive and time-consuming to develop.

So it's really about speed and endurance when submerged and here's a classic hare vs tortoise choice:

LIB only + pump jet propulsor = hare - travel much faster & quieter (2 orders of magnitude quieter) than regular DE subs but only for 10 days
AIP + propeller = tortoise - travel slower but do so for weeks, picking up pace causes cavitation. LIB bank being smaller (to accommodate AIP oxidizer tanks) DE subs cannot afford to burn through battery with sustained high-speed cruising.

But we all know where this is heading; IN not wanting any tradeoffs will want everything & shoot an RFP for DE sub with LIB + pump jet propulsion + AIP + vertical launch cells for missiles (allow ripple-fired salvoes that are more likely to overwhelm a target’s air defenses). That in a nut shell is P75I!

 

[MonaLazy]

You sure? Looks like still on the sail for now.

I see now, you are right! Sorry about the confusion. Those images from 2019 were just speculation, but hey even Popular Mechanics fell for it and they have still not pulled the article from their website!

Taking a Closer Look at Japan's Futuristic Attack Submarine

The sleek underwater warship will ensure the country is defended by the best non-nuclear submarines around.

www.popularmechanics.com

Setting the record straight..

Japan Launches New Submarine Class

JS Taigei is first of a larger, quieter class to face increasingly assertive Chinese warships.

thediplomat.com

But the logic of doing away with AIP like the Japanese to be a fast and quiet attack boat with just LIB+pumpjet still stands! Ambush your prey in his waters and move out fast before you are detected (& killed) from having fired the first shot. It is an offensive mindset.

AIP+propeller helps with endurance at the cost of speed which is better only for tailing a slow-moving enemy sub (Chinese DE subs only, as their nuke boats will be much faster & easily outrun) for a long period of time or lying in wait for enemy assets close to own shores (& hoping they cross paths with you). The moment such a sub picks up pace, it will break cover- so is a sub-optimal utilization of the asset & is a defensive strategy.

 

[MonaLazy]

Looks like the IN is already pursuing the idea..

The Indian Navy was seeking a system that could potentially revolutionise the performance of its conventional (non-nuclear) submarines. The Indian Navy's RFI document envisages the development of a 'high-capacity' lithium-ion battery system. The Indian Navy wants the system to be capable of being refitted to in-service submarines that use lead-acid batteries.

The Indian Navy has specified a 20-month deadline for the lithium-ion battery project from the date a contract is awarded.

Since retrofitment is also sought- may be the Scorpenes can switch from LABs to LIBs in refit & junk the idea of plugging in any AIP & if the propellors could be replaced with pumpjets from France that would be a deadly combo.

Why is Indian Navy eyeing lithium-ion batteries for its submarines?

The Indian Navy has specified a 20-month deadline for the lithium-ion battery project

www.theweek.in

 

[MonaLazy]

Report: Russia pulls out of Indian Navy's P-75I submarine tender, due to lack of functional AIP system.
Germany too will take part, only if changes are made in the tender.



#Russia says it won't bid for #IndianNavy P75I #submarine plan, offers upgraded #kilo class . Essentially leaves #SouthKorea as the only real participant left.
Imho the P75I is dead in the water now.

Russia says it will not bid for Indian Navy's new submarine plan, offers upgraded kilo class

The Russian side has offered India upgraded Kilo class submarines - the type that forms the bulk of the current conventional fleet - but has decided to withdraw from the contest citing technical reasons.

economictimes.indiatimes.com

Russia has said that it will not take part in the Indian Navy's ongoing procurement plan for new submarines, confirming that the Indian government has been formally notified of the decision. The Rs 43,000 crore plan to acquire six new submarines under Project 75I has also hit delays early in the process, with other foreign contenders and Indian partners seeking additional time to formulate their proposals.

The Russian side has offered India upgraded Kilo class submarines - the type that forms the bulk of the current conventional fleet - but has decided to withdraw from the contest citing technical reasons.

"The Russian side has previously confirmed its interest in participation in this programme and suggested a platform based on the design of Project 677E submarine Amur-1650. However, after receiving and studying the RFP finalising terms and conditions of the tender, the Russian side has decided not to participate in the tender for technical reasons," a Rosoboronexport spokesperson told ET.

As reported earlier, the German side, too, has written to the government citing inability to take part in the contest due to technical reasons, including liability clauses and an inadequate budgetary allocation. The German side, however, has now indicated it can take part if changes are made to the tender requirements. South Korea, another contender, is also believed to have concerns about technology transfer.

Pointing to the long legacy of Russian origin submarines in the Indian naval fleet, the Rosoboronexport spokesperson said offers have been made to supply upgraded Kilo class submarines. "To reinforce the Indian submarine fleet, the Russian side has offered both supply of new diesel-electric submarines of time-tested Project 636, and supply of Project 877 submarines after their withdrawal from service with the Russian Navy and upgrade," the spokesperson said.

The Navy's ambitious plan to build six submarines in India under the Strategic Partnership model has hit choppy waters in its early stages, with the condition of a functional Air Independent Propulsion (AIP) spelled out in the technical documents ruling out most foreign collaborators from the project, a move that was followed by sharp protests.

 

[HariPrasad-1]

Report: Russia pulls out of Indian Navy's P-75I submarine tender, due to lack of functional AIP system.
Germany too will take part, only if changes are made in the tender.



#Russia says it won't bid for #IndianNavy P75I #submarine plan, offers upgraded #kilo class . Essentially leaves #SouthKorea as the only real participant left.
Imho the P75I is dead in the water now.

Russia says it will not bid for Indian Navy's new submarine plan, offers upgraded kilo class

The Russian side has offered India upgraded Kilo class submarines - the type that forms the bulk of the current conventional fleet - but has decided to withdraw from the contest citing technical reasons.

economictimes.indiatimes.com

Russia has said that it will not take part in the Indian Navy's ongoing procurement plan for new submarines, confirming that the Indian government has been formally notified of the decision. The Rs 43,000 crore plan to acquire six new submarines under Project 75I has also hit delays early in the process, with other foreign contenders and Indian partners seeking additional time to formulate their proposals.

The Russian side has offered India upgraded Kilo class submarines - the type that forms the bulk of the current conventional fleet - but has decided to withdraw from the contest citing technical reasons.

"The Russian side has previously confirmed its interest in participation in this programme and suggested a platform based on the design of Project 677E submarine Amur-1650. However, after receiving and studying the RFP finalising terms and conditions of the tender, the Russian side has decided not to participate in the tender for technical reasons," a Rosoboronexport spokesperson told ET.

As reported earlier, the German side, too, has written to the government citing inability to take part in the contest due to technical reasons, including liability clauses and an inadequate budgetary allocation. The German side, however, has now indicated it can take part if changes are made to the tender requirements. South Korea, another contender, is also believed to have concerns about technology transfer.

Pointing to the long legacy of Russian origin submarines in the Indian naval fleet, the Rosoboronexport spokesperson said offers have been made to supply upgraded Kilo class submarines. "To reinforce the Indian submarine fleet, the Russian side has offered both supply of new diesel-electric submarines of time-tested Project 636, and supply of Project 877 submarines after their withdrawal from service with the Russian Navy and upgrade," the spokesperson said.

The Navy's ambitious plan to build six submarines in India under the Strategic Partnership model has hit choppy waters in its early stages, with the condition of a functional Air Independent Propulsion (AIP) spelled out in the technical documents ruling out most foreign collaborators from the project, a move that was followed by sharp protests.

Leave all these Chutiyapa and give additional orders of scorpenes with latest technologies. We have spent a long long time in this Chu***a process of tendering. We would have rather designed an ultra modern submarine instead in this time frame. Rather than going for outright purchase, buy required technologies instead if don't have it.

 

[Lonewolf]

Report: Russia pulls out of Indian Navy's P-75I submarine tender, due to lack of functional AIP system.
Germany too will take part, only if changes are made in the tender.



#Russia says it won't bid for #IndianNavy P75I #submarine plan, offers upgraded #kilo class . Essentially leaves #SouthKorea as the only real participant left.
Imho the P75I is dead in the water now.

Russia says it will not bid for Indian Navy's new submarine plan, offers upgraded kilo class

The Russian side has offered India upgraded Kilo class submarines - the type that forms the bulk of the current conventional fleet - but has decided to withdraw from the contest citing technical reasons.

economictimes.indiatimes.com

Russia has said that it will not take part in the Indian Navy's ongoing procurement plan for new submarines, confirming that the Indian government has been formally notified of the decision. The Rs 43,000 crore plan to acquire six new submarines under Project 75I has also hit delays early in the process, with other foreign contenders and Indian partners seeking additional time to formulate their proposals.

The Russian side has offered India upgraded Kilo class submarines - the type that forms the bulk of the current conventional fleet - but has decided to withdraw from the contest citing technical reasons.

"The Russian side has previously confirmed its interest in participation in this programme and suggested a platform based on the design of Project 677E submarine Amur-1650. However, after receiving and studying the RFP finalising terms and conditions of the tender, the Russian side has decided not to participate in the tender for technical reasons," a Rosoboronexport spokesperson told ET.

As reported earlier, the German side, too, has written to the government citing inability to take part in the contest due to technical reasons, including liability clauses and an inadequate budgetary allocation. The German side, however, has now indicated it can take part if changes are made to the tender requirements. South Korea, another contender, is also believed to have concerns about technology transfer.

Pointing to the long legacy of Russian origin submarines in the Indian naval fleet, the Rosoboronexport spokesperson said offers have been made to supply upgraded Kilo class submarines. "To reinforce the Indian submarine fleet, the Russian side has offered both supply of new diesel-electric submarines of time-tested Project 636, and supply of Project 877 submarines after their withdrawal from service with the Russian Navy and upgrade," the spokesperson said.

The Navy's ambitious plan to build six submarines in India under the Strategic Partnership model has hit choppy waters in its early stages, with the condition of a functional Air Independent Propulsion (AIP) spelled out in the technical documents ruling out most foreign collaborators from the project, a move that was followed by sharp protests.

Navy won't budge on TOT terms if they don't wanna participate then they can leave it , they have their own reasons we have our own , neither we can budge , nor they have a functional Aip .
It would be a competition between South Koreans and french

 

[MonaLazy]

Leave all these Chutiyapa and give additional orders of scorpenes with latest technologies. We have spent a long long time in this Chu***a process of tendering. We would have rather designed an ultra modern submarine instead in this time frame. Rather than going for outright purchase, buy required technologies instead if don't have it.

That's true, but now 10+ years have passed with no work on a local design. Some pertinent tweets on why scorpenes may be unsuitable and also agree with IDDM (supplemented with tech bought from overseas where there is a gap) being the way forward as opposed to SPM. IN like the other two services is risk averse and cash strapped for P75I to get anywhere unless SoKo pulls a rabbit out of the hat because of being a newcomer and if GoI seriously pursues it with them- coughing up the money & buying out their AIP, LIB & VLS tech/design & pumpjet propulsors from French and MII in a public or private yard.

P75 uses DRDO's AIP which will not be operational till c2026 & even then, will not power the larger boats of P75I. P75 subs are smaller and therefore lack land attack capability. P75I demands much more tech transfer & localisation than P75.


Basic facts Kanchan da is missing! Defence is a seller’s market not buyer’s market! Speaking “national interest” doesn’t get anyone anywhere here. We can keep sitting on that hill & not induct any new sub until 2040. The tender requirements & the budget are on different planes! Navy is looking for a shrink wrapped custom designed product for its RFP and also the IP so that it can keep making design iterations. But such a customisation ofcourse costs a lot of money and also is new. So obviously both risks and costs zoom. Expecting such a customised product that involves Billions of $$ in new design costs and testing and also the IP for it, at the cost of a 40 year old submarine design is self delusion and ignorance to say the least. And almost all of these require the buyer to take on risks. Navies world over partake in the technological journey pay for the costs and failures and get the product they want. This RFP makes me think that the Navy and MoD wants to keep a hands distance off the manufacturing and only want a final product. That’s not how business works. Technically, we want a 3000T sub with an AIP and a VLS. I'm labeling this Medium Multirole Combat Submarine(MMRCS). We want a product with "India specific enhancements" to be made locally on a new mfg line + the IP @ cost of a base model built at their shipyard in 2010 prices!! India's MMRCS saga continues! Formulate tender such that no OEM would be interested in & see how they all opt out from competing! Will Indian Navy & MoD learn?

Russia says it won't bid for Indian Navy's new submarine plan, offers upgraded kilo class.With this kind of risk and liability offloading, no Indian pvt sector SP partner or foreign OEM would want to compete. Only DPSU shipyards can take on these kind of liabilities.

Navy wants P-76 to be indigenous, that’ll come from the learning’s of P-75I. But the gap is just too large. Going the consultant route also cost Atleast $3-5 Billion just for the consultation. Is India ready to cough up such money?

The ask excludes most OEMs from the competition and will not result in competitive price or a deeper ToT than we got in the past from the Germans ,French or Russians ? Only IDDM can meet our specific requirements.


Are we again moving towards quashing of RFP?
God knows why the Navy/MoD wants a ToT if they never build on it. What will you do with the know-how/why absorbed during the P75 project? Again P75I has ToT clause but after 10 yrs they will start scouting for different class of subs If this continues then we surely will never be where South Korea is. Not even after 50 years.


This might just be a #tejas moment for the #IndianNavy which now has no reason to go in for a new #import design given nobody is ready to meet it's lofty requirements . We should take this as a sign & double down on domestic #Subamrine construction with additional Scorpenes .


Every single one of the mega deals pursued under SPM (NUH, NMRH, MRFA, P75I) has fallen apart and zero results 8 years later can be seen

Yet to the services all is well

Generations of officers come and go handing over junk from one to another

 

[HariPrasad-1]

That's true, but now 10+ years have passed with no work on a local design. Some pertinent tweets on why scorpenes may be unsuitable and also agree with IDDM (supplemented with tech bought from overseas where there is a gap) being the way forward as opposed to SPM. IN like the other two services is risk averse and cash strapped for P75I to get anywhere unless SoKo pulls a rabbit out of the hat because of being a newcomer and if GoI seriously pursues it with them- coughing up the money & buying out their AIP, LIB & VLS tech/design & pumpjet propulsors from French and MII in a public or private yard.

P75 uses DRDO's AIP which will not be operational till c2026 & even then, will not power the larger boats of P75I. P75 subs are smaller and therefore lack land attack capability. P75I demands much more tech transfer & localisation than P75.


Basic facts Kanchan da is missing! Defence is a seller’s market not buyer’s market! Speaking “national interest” doesn’t get anyone anywhere here. We can keep sitting on that hill & not induct any new sub until 2040. The tender requirements & the budget are on different planes! Navy is looking for a shrink wrapped custom designed product for its RFP and also the IP so that it can keep making design iterations. But such a customisation ofcourse costs a lot of money and also is new. So obviously both risks and costs zoom. Expecting such a customised product that involves Billions of $$ in new design costs and testing and also the IP for it, at the cost of a 40 year old submarine design is self delusion and ignorance to say the least. And almost all of these require the buyer to take on risks. Navies world over partake in the technological journey pay for the costs and failures and get the product they want. This RFP makes me think that the Navy and MoD wants to keep a hands distance off the manufacturing and only want a final product. That’s not how business works. Technically, we want a 3000T sub with an AIP and a VLS. I'm labeling this Medium Multirole Combat Submarine(MMRCS). We want a product with "India specific enhancements" to be made locally on a new mfg line + the IP @ cost of a base model built at their shipyard in 2010 prices!! India's MMRCS saga continues! Formulate tender such that no OEM would be interested in & see how they all opt out from competing! Will Indian Navy & MoD learn?

Russia says it won't bid for Indian Navy's new submarine plan, offers upgraded kilo class.With this kind of risk and liability offloading, no Indian pvt sector SP partner or foreign OEM would want to compete. Only DPSU shipyards can take on these kind of liabilities.
View attachment 137899

Navy wants P-76 to be indigenous, that’ll come from the learning’s of P-75I. But the gap is just too large. Going the consultant route also cost Atleast $3-5 Billion just for the consultation. Is India ready to cough up such money?

The ask excludes most OEMs from the competition and will not result in competitive price or a deeper ToT than we got in the past from the Germans ,French or Russians ? Only IDDM can meet our specific requirements.


Are we again moving towards quashing of RFP?
God knows why the Navy/MoD wants a ToT if they never build on it. What will you do with the know-how/why absorbed during the P75 project? Again P75I has ToT clause but after 10 yrs they will start scouting for different class of subs If this continues then we surely will never be where South Korea is. Not even after 50 years.


This might just be a #tejas moment for the #IndianNavy which now has no reason to go in for a new #import design given nobody is ready to meet it's lofty requirements . We should take this as a sign & double down on domestic #Subamrine construction with additional Scorpenes .


Every single one of the mega deals pursued under SPM (NUH, NMRH, MRFA, P75I) has fallen apart and zero results 8 years later can be seen

Yet to the services all is well

Generations of officers come and go handing over junk from one to another

If we can not finalize a tender in 10 years, this means that we could have made an excellent design and realized critical technologies in this time. If we take toooooo long time in even purchase, we may get a n indigenous product in mean time. If we start MMRCA today, we can get MWF by the time MMRCA arrives. So better to go for indigenous product rather than going for purchase. Since we have made Scorpene here and bought Rafale after a lots of efforts, it is better not to do this tiresome exercise again. Either repeat the order or make it ourselves.

 

[BON PLAN]

If we start MMRCA today, we can get MWF by the time MMRCA arrives.

Or not.
Unfortunately no indian weapon program end in the estimated time.
I don't know if MMRCA will be inked, but at least some more Rafale will be ordered, because IAF is very happy with it, and because you pay for special features. It would be a scrap not to spread this amount on more than 36 jets.
My estimation is a final quantity between 72 and 108.

And don't forget the 2 bases accomodated to Rafale can easily host 36 birds each.... (Saint Dizier air base in france hosts more than 45 jets).

 

[MonaLazy]

Or not.
Unfortunately no indian weapon program end in the estimated time.
I don't know if MMRCA will be inked, but at least some more Rafale will be ordered, because IAF is very happy with it, and because you pay for special features. It would be a scrap not to spread this amount on more than 36 jets.
My estimation is a final quantity between 72 and 108.

And don't forget the 2 bases accomodated to Rafale can easily host 36 birds each.... (Saint Dizier air base in france hosts more than 45 jets).

Saurav Jha of Delhi Defence Review says the 114 MRFA will happen & Rafale makes a lot of sense.