A Need!

-By Battle Machines

India has made massive strides in its nuclear submarine program in the last decade or so. This platform has been instrumental in keeping us posted about some of the very recent developments that are very interesting, below is the link to it. But as a country with a finite defense budget, it is difficult to go all in on nuclear powered submarines in the short term. They are excellent platforms but also impressively costly over their lifespan, thus conventional submarines or SSKs are still and will be the prime focus for fleet numbers for decades.

Nuclear Submarine Program details are here

Current Problem 1: All Diesel Electric Fleet Submarines

India currently operates three types of conventional submarines.

1.      Kilo class / Project 877EKM or Sindhughosh class


2.      Type 209-1500 or Shishumar class


3.      Scorpene class or Kalvari class

The problem is all these are the same type of submarine. They all are diesel electrics so they have to snorkel or surface to run their diesels to recharge their batteries and then spend a few days to a week submerged trying to use the battery as scantily as possible so as to extend time between snorkeling. A diesel electric submarine is 3rd placed when compared to AIP equipped submarines (2nd) or nuclear submarines for submerged endurance. They can at the most stay submerged for a couple of weeks with very light usage (sitting idle or 5kn transits) and a week or so with medium usage (10-15kn transits included). Time at high-speed 20+ kn is counted in minutes not hours or days like AIP submarines.

There is some respite though, India plans on equipping its Kalvari class submarines with a homegrown Fuel Cell AIP system. But this will be added in mid-life refits that are atleast a decade down the line. In the interim, new AIP submarines should be quicker to procure.

Current Problem 2: Too many types of Submarines!

The three classes I mentioned above share very little hardware and are thus very expensive to operate at the small fleet sizes India has. India has 7 active Sindhughosh class submarines, 4 Shishumar class and 6 planned Kalvari class. No new orders have been placed as of end of April 2023 for conventional submarines. The weapons these carry are different to and except torpedoes in Shishumar and Kalvari no submarine shares anything.

For example

1.      Sindhughosh class: Klub cruise missile and Type 53 torpedo

2.      Shishumar class: Harpoon cruise missile and  SUT/SST torpedoes

3.      Kalvari class: Exocet cruise missile and SUT/SST torpedoes

India needs to maintain 5 weapon types for its 3 submarines, although the surface fleet and P-8Is use Klubs and Harpoons but remember submarine launched missiles are different variants and require unique maintenance procedures.

Current Problem No. 3: Pakistan’s AIP fleet of Submarines.

Pakistan operates 3 MESMA AIP and 2 Diesel Electric variants of Agosta class which while old offer superior submerged endurance than diesel electrics. The plan is to buy 8 Type 039 based Hangor class which are Stirling engine powered AIP submarines as well. India is looking at upto 11 AIP equipped submarines in its backyard superior to its diesel electric fleet.

My Opinion: Here is what I as an armchair submarine lover recommends.

1.      Consolidate around Scorpene class and place follow on orders NOW!

2.      They should be AIP equipped from the onset.

3.      Sustained production with follow on orders at regular intervals atleast 16-24 boats over the next 20 years.


The writer has been blogging about mil-topics on their website battlemachines.org and Facebook page Battle Machines. For more Indian Navy articles from the writer visit battlemachines.org.
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By Alpha Defense

Alpha Defense initially a solo venture but now a defense group by people from various demographics of India covering defense news and updates. We believe in unbiased analysis of every subject in hand. Our mission is to provide simplfiied defense information to the public.

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