September 1, 2017

India's New SSBN, INS Aridhaman, and its Nuclear Missiles

INS Arihant (4 vertical missile tubes) is acting as a missile testbed for some missiles that INS Aridhaman (8 tubes) will eventually deploy (Graphic courtesy DRDO, H I Sutton and The Diplomat via several publications, eg. the Dhaka Tribune).

Following INS Aridhaman's (probably) Symbolic Launch late 2017 Ghalib Kabir has provided additional comments . When added to Pete's research based mainly on footnote [1] this yields:


The imminent (symbolic "soft"[2]) launch of INS Aridhaman has been a strong rumor since April 2017 at least (not surprising considering the construction work since 2011). Ghalib would wager that the 'proper' ["hard"] launch is likely in early 2018, then sea trials by early 2020, with commissioning by late 2021. 

Nuclear Tipped Missiles

Ghalib hopes India retains the 8 vertical launch tube format for the 3,500 km range, 17t, 12m long K-4 SLBM layout. [Pete estimates the K-15 "Sagarika" may be used on Aridhaman for several years (to 2025?) before the K-4 is a mature missile system.] But the K-15 has many deficiencies including a short 800km range useless [against the city of Islamabad and China] with a light (up to 800kg) warhead. [Pete - Even India's Nirbhay cruise missile has a longer range of 1,500km.] Ghalib hears that the current concept of the K-5 SLBM might have 3 MIRVs per missile [3]. [Pete - However some doubt India is trying to develop MIRVs at thiis stage] [4] Initially the K-4 missiles might carry a single warhead only (like a Pu boosted fission device) [Pete - or 2 stage mainly fusion?].

Submarine Reactor Development

Russia's VM-5 [5] reactor (used on Russia's one and only Project 661 class test SSN (K-222) formed the on land (at Kalpakkam near Chennai) testbed for Ariahant's 83 MWt reactor. Russian assistance allegedly stopped in 2015-16. The VM-5 design probably formed the basis for some Indian submarine reactor improvements resulting in Aridhaman's reactor being uprated to 100 MWt.

Ghalib comments - according to Indian scientists more than 'Know-how' it was Russian 'Show-how' [of a submarine reactor and other nuclear submarine technology] that was more useful. I think thats the key here. To be 'shown how' makes for the actual breakthrough. See Page 135 of this book talks of Russia and Arihant's 83 MWt reactor:

Further reading on the special Russian-Indian nuclear submarine relationship is at [6] and [7] below.


[1]  Information on Indian SSBNs and SLBMs are on pages 130 to 138 of Peter Lobner’s “60 Years of Marine Nuclear Power: 1955-2015 – Part 4 – Other Nuclear Marine Nations”, dated August 2015, large PDF (around 20MB)

[2]  "soft launch" is when a submarine under construction stays on dry land after the "launch" ceremony or is launched into the water but is then returned to dry land for further construction. 
A well documented example of a soft launch was when  HMAS Collins was launched into the water on August 28, 1993 to meet a political schedule. When launched Collins was incomplete with the design not even finalised. At “launch” on August 28, 1993 important internal pipes and fittings were not installed, the components of the combat system had yet to be delivered, and some hull sections were actually sheets of timber painted black so the submarine would appear complete in photographs of the launching ceremony.  Within weeks of the “launch”, Collins was removed from the water, and it was not until June 1994 that the submarine was completed then really “hard” launched.]

[3] If the K-5 is closely based on the Agni V then the K-5 may eventually have 3 to 10 MIRVs per missile. Also the follow-on K-6 may have 10 MIRVs (See Agni VI wiki and right sidebar).

[4] Hans M. Kristensen and Robert S. Norris “Indian nuclear forces” in Bulletin Of The Atomic Scientists, 2017 Vol. 73, No. 4 page 5 (208) argue that India has to prioritise given the limited payloads/range of Agno V and VI missiles. India may prefer to at least be capable of hitting distant targets (read targets in northeast China eg. Beijing) with a single warhead per missile rather than having MIRVs which would prevent Agni V/VI's hitting Beijing. 

[5] Pete is puzzled the right sidebar for K-222's VM-5m records:
"2 × VM-5m type pressurised water reactors, 177.4 MW (237,897 hp)
2 × steam turbines, 2 shafts
80,000 shp (60 MW)"
How can that data be converted to one reactor of 100 MWt?

[6] Verghese Koithara, Managing India's Nuclear Forces, link.

[7]  Rakesh Krishnan Simha in “Arihant: How Russia helped deliver India’s baby boomer” Russia & India Report, 26 October 2015 “As India’s first nuclear powered submarine prepares for its maiden missile launch, a look at the extent of Russian assistance in the Arihant project.”

Ghalib Kabir, Pete and the Authors cited


GhalibKabir said...

The lyncean data dates to 2015 for Indian missiles. the table is still accurate largely for the K-4 and K-5, for the Brahmos and Nirbhay there are substantial changes esp. post MTCR

The Indian SSNs might have a VLS and Torpedo tube launched combo of

1. Brahmos Extended Range: post MTCR range tested to 450 km and upgrades to 600 km (full range of the Oniks) underway incl.both anti-ship and LACM.

2. Nirbhay: At 1000-1500 km, the Nirbhay should form the mainstay of the SSN fleet for longer range strike. the only drawback is the nuclear capacity is in all likelihood restricted to around 10-15 kT yield warhead owing to the small diameter of the missile.

With the Varunastra torpedo, this should round out the main armaments of the Indian SSN.

India not choosing to MIRV is a nod to Washington since the Vajpayee administration (circa 2000 onwards). a mistake in my opinion in the face of brazen arms proliferation by beijing to its client pakistan (plus washington is the worst 'friend' to have)

Anonymous said...

[Unclear if the author wants to be identified. So comments below are anonymous]

Just wanted to say India does not have a verified thermonuclear weapons capability as the 1998 test was a fizzle. So no fusion device in the K series missiles or Agnis.

What it does have and successfully tested in 1998 was a boosted fission device ( tritium acting as a booster in a Pu core) that gives yields up to 150 kT.

I do read that after the new carbon centrifuges installation at Chitradurga in Karnataka, India is making Weapon Grade Uranium (WGU),
[ ]. However the original design problem still stands and in a way is irrelevant as a 3 MIRV carrying boosted fission devices will deliver nearly 0.5 MT ... With added radiation poisoning from the decaying radioactive elements.

Another choice in a boosted fission device is cobalt 60 used as a contaminant to deliver long term economic punishment esp as part of a second strike.


PS: Bharat Karnad claims in his blog security wise dated August 25 that Aridhaman will be fueled and be going for trials soon . I doubt the speed he seems to suggest. You might want to read it.

Peter Coates said...

Thanks Anonymous

The blog entry to which you refer Is title/date: "10 days to fueling the Aridhaman" August 25, 2017

Which begins: "The second indigenous Arihant-class SSBN, INS Aridhaman, is completely outfitted, all inside of 7 years from the time when its keel was laid at the Vizag special projects facility [in or near Visakhapatnam Naval Base, Indian east coast]. It took less time to produce than the Ohio-class SSBN rolling out of the General Dynamics Electric Boat facility at Quonset Point, Rhode Island, and Groton, MA, which complex has by now manufactured over a hundred SSBNs and SSNs for the US Navy."

Pete Comment: These alledged Aridhaman timings (with a near new reactor) seem an implausible rush compared to the years of Arihant took (from "launch" to commissioning). This is probably more national pride/achievements talking than a conservative project timelines estimate.