Project 75I - It Begins

[Aditya G]

Considering how big Brahmos is, I find it hard to see an SSK equipped with Brahmos... leave alone 16 missiles in it.

Brahmos-M/NG seems to be the only viable alternate in the Brahmos family for integration with P75I subs.

Then why have P-75I at all? Why not continue building Project 75 Scorpenes?

No VLS => scrap the programme.

[member_23370]

Because the SSK's only carry 18 torpedos why waste space for missiles if you can put them in VLS tubes.

[Ankit Desai]

Looks like it is going to private ship yards.

Navy to MOD: Avoid Mazagon Docks for Project-75I

Indian Navy in its recommendation to Ministry of defence (MOD) has asked to avoid giving any orders to State-owned Mazagon Docks for local construction of new Conventional submarines under Project-75I.

Recommendation highlights major mistrust between Indian navy and Countries only State-owned Shipyards with any experience in building submarines in India. Experts say recommendation by India navy will not be easy to be ignored by MOD.

Navy observation says shipyard is overflowing with orders and does not have the capability to stick to deliveries. 6 Scorpène submarine under construction at Mazagon Docks is already behind schedule by four years, one of the major reason reported was due to Mazagon Docks inability to build capacity in house which lead to delays . recently Defence minister Manohar Parrikar in Rajya Sabha also confirmed that delays under Project-75 was due to Mazagon Docks inabilities to absolve TOT .

Indian navy is also against any order to be given to Hindustan Shipyard located at Vishakapatnam. Hindustan Shipyard has also come under heavy criticism for last few years after it botched up mid-life upgrade of a kilo class submarine INS Sindhukirti which has been under mid-life refits in shipyard from 2006 onward and even after 9 years Shipyard has not been able to deliver the submarine to Indian navy Delivery schedule is already delayed by 6 years from the original estimate of 3 years.

-Ankit

[Yagnasri]

Good that IN is speaking up. Public Sector Shipyards, OFB and others like HAL needs to be reformed immediately to stop dependency on imports. Hope MP will do something in this regard.

[srin]

So, what are we going to do with MDL's hard-gained expertise in building submarines now ? Remember, one of the reasons for delay in Scorpene project was the re-skilling of the MDL's workers (after HDW construction stopped).

Looks like we're going to repeat the same thing again.

[abhik]

^^^
It a lifafa article. AFAIK the public sector shipyards are headed by ex Navy officers nominated by the IN. Which is probably why there is very little acrimony unlike say IAF and HAL. And MDL sub line will close down in around 2020.

[Singha]

Mdl could move to building modules or whole of the n_subs once scorpenes are done

[arshyam]

^^ Can't we have MDL build another set of 6 Scorpenes once the initial order is filled? It will help build numbers, make the most of hard earned skills, and since the latter part of P75 will have the DRDO developed AIP, the next 6 will also have them from the out set. Also, as a follow on order, I am guessing the MoD need not float global tenders, etc. and save time in getting started with the new order. So, we could be looking to have 6 P75, 6 P75I, and 6 from the follow on order, which means a healthy diesel sub fleet.

It depends on what the Navy wants. Anyone know what the IN is thinking?

[pankajs]

IIRC, the idea behind Project 75I was always to get a second submarine building facility in India for strategic reasons. This does not take into account the nuclear powered sub building. That by itself excludes MDL from playing any part in Project 75I. Moreover, the down select has made it clear that MDL is not in the picture for Project 75I.

MDL will *eventually* get more orders for Scorpenes or a modified Scorpenes but GOI will wait for deliveries on the current order before initiating any fresh proposals.

[Philip]

Apart from delivery on time and of the required quality,the fact remains that the Scorrpene cannot carry much of the newer weaponry developed in the last decade particularly BMos.Israeli Dolphins have two sizes of TTs,the larger ones for their N-tipped cruise missiles.The non-AIP SCorpenes that the IN is acquiring are also prohibitively expensive.One can buy approx. two Kilos/Amurs for that price.

Given the IN's visionary masterplan for its subs for the future,with the emphasis on N-subs,where about 7 SSBNs and at least 6 SSN/SSGNs apart from the 2 Akula SSGNs planned,for true bluewater ops,the N-subs will do the business admirably. 2 SSNs are being earmarked to protect each carrier task force (3 planned).The remaining 18 or so conventional AIP boats will be used for littoral warfare mainly.The Scorpene's MESMA AIP system is also a bit long-in-the-tooth,and some say inferior to fuel-cell with newer improved fuel-cell AIP modules of the second gen. in the pipeline.Thus there is no need to acquire/build very expensive conventional subs,mirroring N-subs in capability which non-nuclear navies are attempting to do like Japan,SoKo,Oz,etc.

Having the pvt. sector to build subs for us would be great as MDL and the other DPSU yards have ample orders.HSL's N-sub facility at Vizag will be busy for two decades with the N-subs on order! Why are they complaining? To maintain MDL's sub building capability,another 2 Scxorpenes may be ordered after the first batch of 6 are commissioned. There are also midget subs,UUVs,etc. whioch the IN needs,plenty of work in the future.

[Philip]

A v.good video clip of the new Israeli Dplphin,the Tanin here,plus the German fight to win the 75I contract...not to mention the Japanese throwing their hat into the ring with the Soryus. The fight is going to be intense when you add the Russians into the IOR undersea war for the Indian contract!

1.http://www.israelnationalnews.com/News/News.aspx/193350

Take a Sneak Peak at Israel's Secret Submarine Fleet

Israel's nuclear-capable INS Tanin able to operate deep within enemy territory - to lethal effect.

By Uzi Baruch

First Publish: 3/29/2015,
New footage from the Israeli Navy showcases the most advanced submarine in the IDF's arsenal: the Dolphin-class INS Tanin (Crocodile).

The nuclear-capable submarine boasts an array of sophisticated weaponry, as well as the latest in intelligence-gathering technology.

It stands at a whopping 68 meters long, compared to 57.3 meters on average for other submarines.

"The submarine will receive more long-term missions, and for a greater amount of time, than submarines" the IDF possesses, one navy officer explained, adding that as a result the Navy had "extended by several days our ability to operate silently and secretly in enemy territory."

The submarine's commander, Lieutenant Colonel "G", echoed those sentiments, adding that as a result of the sensitive nature of the missions it will be undertaking only the most elite navy personnel will be operating it.

"Even the smallest mistake by a soldier could foil the mission in the best-case scenario, and in the worst case reveal the submarine and leave it vulnerable to attack," he said.

Sailors worked closely with the defense ministry, intelligence agencies, the air force and other elite IDF units, he added.

Commander of Haifa naval base General David Salamah explained the importance of Israel's submarine fleet to national security.

Israel's submarines regularly operate "deep within enemy territory", he noted.

"We are talking about a major upgrade to the navy and the entire IDF, in the face of the challenges posed to the State of Israel."

2. http://www.marinelink.com/news/submarin ... 88468.aspx
Germany Fights for Indian Submarine Contract
By Aiswarya Lakshmi

German giant ThyssenKrupp Marine Systems (TKMS), the parent company of leading submarine builder HDW, will offer India its HDW Class 214 vessel, with an eye to huge project of Indian Navy for six submarines, reports PTI.

TKMS is also in talks with leading shipyards in the country for a tie-up and promising a no-hold barred transfer of technology in line with the Narendra Modi government's 'Make in India' push.

The Indian Defence Ministry is expected to issue the P-75I RFP for which TKMS is planning to offer the Type 214 submarine, which combines best-in-class underwater endurance and diving depth, Gurnad Sodhi, Managing Director of TKMS India) said.

The HDW Class 214's "proven" fuel-cell based Air Independent Propulsion (AIP) system is the best available on the market, he said. He claimed that the submarine is highly regarded for anti-surface and anti-submarine operations, intelligence, surveillance, and reconnaissance capabilities.

The company has shortlisted Indian shipyards for a tie-up and discussions are on. It is awaiting the report of the special committee set up by the Defence Ministry.

3.http://www.japantimes.co.jp/news/2015/0 ... Rk9UMv9ljo

India interested in buying Japan’s Soryu-class submarines
Mar 29, 2015

NEW DELHI – Indian Defense Minister Manohar Parrikar has expressed his readiness to consider acquiring Soryu-class diesel-electric submarines used by the Maritime Self-Defense Force.

“We are very much interested in Japan’s technologies,” Parrikar said in an exclusive interview ahead of his visit to Japan from Monday.

The issue may be taken up at his meeting with Defense Minister Gen Nakatani the same day, according to Parrikar. “Everything is on agenda. We can discuss that issue,” he said Saturday.

India’s navy has a fleet of 15 submarines, but more than half are not equipped to respond quickly to contingencies due to aging. In view of the growing activity of Chinese submarines in the Indian Ocean, New Delhi has put a high priority on arms buildup to strengthen maritime security.

Japan’s Soryu-class submarines are seen as among the most advanced nonnuclear attack submarines in the world.

Parrikar noted that Japan had strict regulations on the export of defense technologies but that the rules are changing. “We are looking at all kinds of defense cooperation with Japan in all fields,” he said, signaling intention to acquire Soryu-class submarines if the amended conditions are met.

Australia is also in talks with Japan on buying Soryu-class submarines.

In the interview, Parrikar suggested that India is not likely to make a decision anytime soon on whether to purchase US-2 amphibious rescue aircraft used by the MSDF. Tokyo and New Delhi are holding talks on the export of US-2 aircraft to India and a possible joint venture to produce them on Indian soil.

“It will not be decided in Tokyo,” Parrikar said. “I have directed the (Indian) Navy and Coast Guard to come up with a clear-cut report on their operational necessities. First we need to define details.

“Without that report, we cannot go forward,” he said.

[Hitesh]

I do not understand India's SSK procurement policy. If you already got the Scorpenes and need 6 to 12 more, why can't you just make 6-12 more Scorpenes and save yourself the hassle of dealing with 2-3 different types of sub and only deal with one type of sub, especially if you are also dealing with nuclear subs as well. Sometimes, I just want to bang my head at the wall whenever I hear of MoD's procurement policies. It is like watching a bunch of monkeys clowning around in the office as part of that tv ad.

[pankajs]

The Navy/MOD policy has been for some time (15+ years)to have two lines of conventional submarines being built in India. The latest RFP (or whatever it is called) is in line with that policy.

The Navy knows it business and the rest of us are like monkeys clowning around as you have put it quite well.

[member_28722]

No... he speaks sense
2 lines of conventional subs make sense when you don't have nuke boats.
We will have Scorpene, 75I, Arihant production and also facilities capable of maintaining Kilo & Akula class.
Is 75I with VLS a signal that there will be no SSN only limited SSBN?

[pankajs]

I will go by the words on the Navy. Kilo and Akula, etc don't count for the requirement was to have 2 line of conventional sub *building* in India.

[Hitesh]

The Navy/MOD policy has been for some time (15+ years)to have two lines of conventional submarines being built in India. The latest RFP (or whatever it is called) is in line with that policy.

The Navy knows it business and the rest of us are like monkeys clowning around as you have put it quite well.

That policy made sense when there were no nuke subs on the horizon. Now you are dealing with two Akula subs and 5 Arihant subs, two different designs of nuke subs. And you are dealing with Kilos who just underwent a midlife upgrade which tells me that they will be used for 20 more years. So that is one line of conventional subs. Add in the Scorpene and then throw in the Project 75I. Now you are talking about 5 different types of subs!!! Not even the US Navy is so stupid to go through that hassle. At the most they were willing to deal with was one conventional sub and two nuke subs. They are phasing out the 688Is and made the Virginia subs as the successor subs to the 688Is, meaning that there are some commonality between the two subs and the Seawolf subs which they capped at 3 which also shared some commonality with the Virginia class subs.

So I stand by the monkeys clowning around remark.

[pankajs]

ATV was on the anvil when the plans were made. I will defer to the Navy any day on Naval defense than armchair admirals. The requirement was and is to have 2 line of conventional sub *building* in India.

I too support your clowning remarks except for a different crowd (armchair admirals).

[Hitesh]

ATV was on the anvil when the plans were made. I will defer to the Navy any day on Naval defense than armchair admirals.

Well I am not. Navy is in charge of naval warfare and prosecuting the goals and aims of India and its maritime policy but civilians are in control of the overall strategy picture and meeting its needs. There are times where you have to tell the Navy to make do with what they have and be realistic.

And I am telling you that no other navy would do what the IN would do - create 5 different lines of subs at the same time. It is not strategically feasible because you need to account for the infrastructure and the supporting industry that comes with it to support those subs. India doesn't have that much of money that Uncle Sam has so as the saying goes, "We must cut our coat according to the cloth"

From a budget standpoint, there is no way in hell that India can support 5 lines of subs. It is not just possible.

[pankajs]

The Navy is not creating 5 lines of sub *building* but is working on 3 lines , 2 conventional and 1 nuclear lines. By the time the 3 lines get up to speed, the HWDs and Kilos will start retiring and new iterations of indigenous design will start appearing. The same as with the Surface combatants.

The past civilian/military leadership(s) and the current civilian/military leadership are in agreement for I have not heard one murmur against the plans till date in 15 years. They obviously must have done the budgeting.

[Hitesh]

You left out the Kilos and the Akula class. They need year round maintenance to keep them running smoothly.

[Gyan]

Navy should release Tot and drawings of Scorpene and HDW subs to PVT sector and ask them to make follow up versions for indigenous series

[pankajs]

Just have to look at the various versions of the surface combatants that are being induced into the Navy. Every decade we have a new design being churned out by the same shipyards for the major ships (Destroyers and Frigates).

The same will happen with the subs as the Kilos, HDWs retire and the Akulas go back after 10 years. Scorpene and P75is are by no means the end. Give it a decade at max after P75i contract is awarded to the next sub design being proposed.

[member_28722]

Just have to look at the various versions of the surface combatants that are being induced into the Navy. Every decade we have a new design being churned out by the same shipyards for all kinds of ships.

The same will happen with the subs with time as the Kilos, HDWs retire and the Akulas go back after 10 years. Scorpene and P75is are by no means the end. Give it a decade at max after P75i contract is awarded to the next sub design being proposed.

Cain't compare surface fleet to Navy
Essentially we have a single line of destroyers and 2 lines of frigates which have (or will have) very similar weapon payload
Scorpene is very different from Kilo
P75I is different from both
With Arihant and Akula we have 2 nuke subs
In the next decade we will be have 5 lines of subs. No single nation has done that since WW2. I don't see the logic behind having both P75I and SSN

[Philip]

Look at Russia,or even China for that matter.They have several types and classes of subs. However,much of the eqpt./components are the same,not forgetting weaponry.Russia and China operate both N-subs,SSBNs,SSGNs and conventional types. Out ATV programme has developed components and eqpt. which will be common for both the SSBNs and SSNs.These have also been according to some sources based upon detailed drawings given to them by the Russian design bureau which was the consultant for the ATV programme. Some sources also say that there is commonality with Akula eqpt. too.

The Kilos and U-209s will within 10+ be phased out,perhaps a few remaining as reserves or for training purposes.That is a total of 13 subs.These will be replaced by just 6 Scorpenes,4 non-AIP. . At least another 6-8 conventional AIP subs are required as replacements,one-for-one.18 conventional subs is the optimum minimum number that the IN should possess. The Scorpenes are obscenely expensive and armed with inferior Exocets.Hence the need for the 6 SSN/SSGNs,which will have VLS silos apart from the std TTs,with perhaps two sizes of TTs.Eventually,we may have two lines of N-subs,SSGNs and SSBNs and two lines of conventional AIP subs,one western and one of eastern origin to stay abreast of the best from east and west until we are able to master sub tech and design ,develop and build our own conventional AIP subs.

[Hitesh]

Even 4 lines are too much, even for America and Russia. Russia is struggling and barely able to put in 6 -8 subs in sea at one time and they are downsizing the number of sub lines to make the cost of the submarine arm go lower. If I was the MoD, I would go with one line of nuke sub and one line of conventional sub. Make the Project 75I as the indigenous program and merge the Scorpene sub program with Project 75I. Phase out the Akulas as you get more Arihant subs online and subsequent newer designs. This way, you get all the machinery and support structure within the country.

[arshyam]

Hitesh sir, maybe the idea is to disperse our capabilities in order to serve as backup in case one or more facilities are taken out during war? Having only MDL for diesels and Vizag (L&T + HSL?) for nukes means that in the event of hostilities, our capabilities will be crippled if either of these are damaged. I am not considering HSL as a player in diesels for now, given their experience with Sindhukriti, we will have to wait and see. Plus, being in Vizag means HSL could also be damaged in this scenario. Anyway, such actions will have a direct impact on MRO for subs.

See what we are doing for shipbuilding - MDL, GRSE, now CSL all have built up some capability, soon to be followed by Pipavav and Kattupalli (hopefully). Granted, they are now sort of specialized in destroyers, frigates/corvettes, and carriers respectively, but the experience gained by each can be used to do at least some amount of MRO and keep the fleet going during a crunch.

I think the idea behind different Scorpene + P75I is to eventually hedge against such risks, and to have 2 different diesel sub lines in the long run (and 1 nuke line). Our littoral sub requirement will likely be revised upwards of the 24 subs-by-2020 plan, given the aggressive Chinese threats, the need to show the flag in neighbouring areas like SL, Maldives, etc., and the need for nukes to go longer and farther away from the home land. So reliance on diesels will increase in order to secure the coastline, and leave the nukes to do the strategic stuff.

Two diesel lines make sense if we think of having 30-40 diesel subs eventually. That number will mean around 5-10 subs in refit at any time, plus new sub construction, which requires more capacity than MDL can provide currently. Also, these sub numbers are not too far fetched, given the 51 SSKs the PLAN has to defend a ~14000KM coastline. Our coastline is only 7516KM (per Wiki) so we may not need that many SSKs, but we definitely need more than what we have today. Finally, our requirement is different in that we will need more SSNs to secure our IOR region, so a sub fleet of 40 SSKs + 15 nukes (attack or boomer) seems plausible in the next 30 years.

Given this, the non-MDL P-75I plan makes perfect sense. I just hope MDL gets some follow-on orders for more Scorpenes soon after commissioning the first few in the next 2-3 years.

[Prem Kumar]

That policy made sense when there were no nuke subs on the horizon. Now you are dealing with two Akula subs and 5 Arihant subs, two different designs of nuke subs. And you are dealing with Kilos who just underwent a midlife upgrade which tells me that they will be used for 20 more years. So that is one line of conventional subs. Add in the Scorpene and then throw in the Project 75I. Now you are talking about 5 different types of subs!!!

Make it 6 (possibly 7) types of subs, counting both conventional and nuclear!

1) Akula (refit/maintenance)
2) Kilo (refit/maintenance)
3) Arhant-class subs, to be completed by 2023 (4)
4) Larger, 10K tonne Arihant class boomers with 12 K-5s to be built by 2025 (3)
5) SSNs, which may or may not reuse the 83 MW reactor of the Arihant class. To be built in parallel & completed by 2025 (6)
6) Scorpene
7) Project 75I

Nice article in India Today about nuclear submarine building plan http://indiatoday.intoday.in/story/india-china-relations-modi-government-indian-ocean-naval-expansion/1/425929.html

[Philip]

Russia is not "struggling" to build and put to sea N-subs ,pl read US and independent reports. They are also building apart from the Yasen SSGN and Borei SSBN N-subs,both Kilo 636.3s and Amur/Ladas for their own navy and exports.A new conventional class is also rumoured to be in the works.In addition,legacy Soviet N-subs are also being upgraded and modernized as these double-hulled subs have 30-40 years of life in them.The Sierra-2 SSGNs are being modernized as well. At one time the In was reported to have been interested in this design.

Our SSBN/SSNs are expected to have many similar featurese main difference being the weaponry carried and extra speed for the SSN/SSGN.We will have only 2 lines of conventional subs being built,Scorpenes will be over within 5-6 years,unless we add a couple more which may happen to keep MDL's sub building capability alive. The 75I line will be moving along ,plus upgrades,etc. to the existing fleet of modernized Kilos and U-209s. These should last us at least another decade. Remember that in the past the In operated 3 types of conventional subs,Kilos,Foxtrots and U-boats as well as a Charlie-2 class SSGN. What is essential is that we have the shore based support facilities up and running (on both seaboards) to maintain our subs so that their operational capabilities are not affected in any way.

[Kakkaji]

I don't think the Japanese will offer their submarines for the Project 75I. I think it is a bridge too far for them coming out of their pacifist policies on arms export.

I think the competition is going to be between the Russians and the Western Europeans. The Russins will likely win out on price.

I don't think India can afford a second line of submarines at Western European prices. If the Amur fulfils the minimum specs from the Navy, it will be selected. L&T will probably get the contract to build it

JMT and speculation

[member_28526]

As in the past, the P75I project cost will probably include payment for tech that has been clandestinely transferred to India so I also think that the contract will go to the Russians.

[pankajs]

Rory Medcalf ‏@Rory_Medcalf Mar 30

Defence Minister Andrews says something like 300 submarines will operate in Australia's wider region by 2030s #FSFleet15

IOR region is going to be swarming with Subs.

[Philip]

Kaiz,not that easy methinks,The Russian tech will definitely be there for the N-sub programmes,SSBNs and SSNs.The German U-boats are also excellent subs,look at the Israeli Dolphins,but may cost much more than a Russian equivalent. If a Russian boat also has a VLS compartment with 8-10 extra missiles like Klub/BMos apart from the usual 18 torpedoes/missiles ,it would give these subs an advantage. The remaining lifespan of our existing U-209s,some being upgraded could be a factor. Some reports say that they will be equipped with sub-Harpoon anti-ship missiles.peculiar decision as the Scorpenes will have Exocet missiles and Russian subs Klubs! The IN appears to be the navy with the fullest "menu" of anti-ship missiles available.

[vishvak]

Rory Medcalf ‏@Rory_Medcalf Mar 30

Defence Minister Andrews says something like 300 submarines will operate in Australia's wider region by 2030s #FSFleet15

IOR region is going to be swarming with Subs.

This is also why we need more and more sub-hunters; and also, to have an understanding with the Chinese not to bother us. Better reduce risks right away.

[Singha]

the russians have had no export success with the Amur class, unlike the U214 which has been sold to turkey, greece, south korea et al and so might be more willing to adapt the design to our need and let us fit all the equipment we want. fitting of brahmosM and nirbhay whether TT or vertical will not be an issue.

with the germans you never know they might deny help on fitting offensive LR weapons like nirbhay >300km range! these are the same clowns that would not export beretta pistols to the BSF on Cashmere HR issues while giving production license of G3 and MP3 to TSP which murdered million bangladeshis in 1971 alone not to speak of af-india ops thereafter.

[Cosmo_R]

I do not understand India's SSK procurement policy. If you already got the Scorpenes and need 6 to 12 more, why can't you just make 6-12 more Scorpenes and save yourself the hassle of dealing with 2-3 different types of sub and only deal with one type of sub, especially if you are also dealing with nuclear subs as well. Sometimes, I just want to bang my head at the wall whenever I hear of MoD's procurement policies. It is like watching a bunch of monkeys clowning around in the office as part of that tv ad.

Because we are interested in the means rather than in the end. We love the process. The more interminable it is, the longer we can put off a decision. And then just as we are ready to decide, someone will identify some 'cheap' subs from the Qataris/Ethiopians/Greeks that only need a minor upgrade from Sevmash whatever.

I am just as bewildered at why we need another line when you'd think that existing tools and experience on building scorpenes, training sailors and MRO could be amortized over a larger run.

BTW, I also don't get why we can build nuke subs but can't build conventional ones ourselves.

[pankajs]

Nothing bewildering about wanting a 2nd and possibly even a 3rd line for conventional subs. It allows you to churn them out faster on multiple lines in parallel.

The 2nd question is if all the lines be with MDL or should they be spread over multiple yards. GOI/Navy in their wisdom believed in having one facility on the east coast and one on the west coast. Don't know if the east coast/west coast logic is still prevalent but having more than one separate sub facility is still desired. A single facility can have multiple lines. This has been the thinking across all governments in the last 15-20 years.

The 3rd question is do we want the same design on all lines or different design on different lines. The original plan was and remains to have at 2 different designs to start with. So we have the project P75 and P75i. Later on an Indian design is supposed to evolve from our experience in building P75 and P75i.

Even when the original plan was devised the ATV was on the horizon and had been factored in separately per reports. The number of conventional vs nuclear will however be adjusted based on the changing threat perception and the Navy mandate.

[Rahul M]

pankaj, that is not a valid argument IMHO. you can always make a 2nd line of the same sub.

[pankajs]

I have noted that *same design on all lines* is an option. The decision to go for multiple sub design has been made by the GOI (Adhering to the original plan). That of-course can be contested.

[VijayN]

I think pankajs is right when he refers to the "Building" local subs here. Hitesh - I think you are referring to the existing line of subs and then arriving on the 5 lines of subs (Correct but not right in terms of "Building"). I just put a rough list of the current inventory/under construction/planned on same lines: I am sure the numbers can be corrected:

Start End
Scorpene 1 2015 2045
Scorpene 2 2016 2046
Scorpene 3 2017 2047
Scorpene 4 2018 2048
Scorpene 5 2019 2049
Scorpene 6 2020 2050
HDW Class 1987 2017 Start dates could be off.
Kilo 1-12?? 2012 2022 Start date as in Refit date
Akula 1 2012 2022 Lease Period Ends
Arihant 1 2015 2045
Arihant 2 2018 2048
Arihant 3 2022 2052
Arihant 4 2024 2054
Arihant 5 2026 2056
Arihant 6 2028 2058
I have taken an avg. life span of 30 years for each new sub and 10 years for refit.
Akula again is leased
HDW is at the end of it's journey

From above, it could be argued that at the end of 2022 (give and take a few yrs), we have have just the Scorpene and Arihant class boats. So it does make sense to introduce the a new line now by above depiction.

[Hitesh]

Vijay,

the Kilos just underwent an expensive midlife upgrade and refit. Obviously they are gonna be around much longer than 2022. Otherwise we are just pissing away money and IN is not known for that. That means the kilos are around for another 20 years. Add Scorpene to that plus P75i. Now you have the Arihant class which I understand the need for it. But then we have two Akula class submarines. Are we planning to keep them only for 10 years until more Arihant subs come online? if so, then we are back to one nuke sub line.

Are we keeping the U212 for much longer? Or are they expected to retire by the time P75i comes online?

What does P75i bring that Scorpene cannot? If there are any, why can't modifications be made to the Scorpene line? The money invested in the modifications would be the same for initially investing into a new line of sub.

If I were the IN, I would stick with Scorpene and build 12 more of them in addition to the 6 to bring it to 18 and then work on the Arihant and produce 12 of them. This way you get 30 subs and only two lines.

Other conventional subs such as the Japanese design and German design bring nothing that two line of subs that India is currently producing and cannot have. Those two subs are enough to make up and counter whatever other sub designs bring.

In the process, we gain the advantages and benefits of amortizations as Cosmo alluded to and simplify the logistic chain and maintenance process and also simplify the training process necessary for operating all of the subs.