August 31, 2017

INS Aridhaman's (probably) Symbolic Launch late 2017

Artist's rendering of the future INS AridhamanDiagram courtesy Indian Defence Research Wing (IDRW)

The following is partly based on Ghalib Kabir's comments of 28 to 29 August 2017 mixed with Pete’s research.

India's future SSBN INS Aridhaman has been under construction at the Ship Building Centre in Visakhapatnam since 2011.  Aridhaman might be symbolically launched in late 2017. Actual  launch (into the water for fitting out) may be in 2018. Then would follow harbor trials and sea trials for 2 years with commissioning expected sometime in 2020 or 2021.

Aridhaman is the second in the Arihant class and is larger than INS Arihant. While Arihant only has 4 large launch tubes Aridhaman has 8 making Aridhaman more useful as an SSBN. Each launch tube will be able to  carry 3 K-15 Sagarika missiles (total of 24) with a range of 750 km or a total of 8 future K-4 missiles (with a range of 3,500 km)
Aridhaman length and displacement will increase due to the 4 extra launch tubes, a longer more powerful reactor, extra crew, more powerful sonars and other mission critical equipment. Aridhaman  may be 125m long and 7,000 tonnes (surfaced) larger than INS Arihant’s 111m and 6,000 tonnes (surfaced). Aridhaman's dimention would be very similar to the no longer operating US Ethan Allan class (at 125m long/7,000 tonnes). 
Aridhaman will have one seven-blade propeller powered by a PWR reactor. INS Arihant has a 83 MWt (12 MWe, 16,000 shp) reactor while Aridhaman may have a 100 MWt reactor (approx 16 MWe or 20,000+ shp)

The increase in power of Aridhaman's 100 MWt reactor may be achieved by many means including:
-  larger size 
-  higher HEU than the usual 40% for Indian nuclear subs (see page 67 of this pdf) and
-  higher steam pressure

If the reactor heavily relies on Russian design assistance then Russia’s VM-4 reactor (70-90 MWt) may be an influence. Alternatively India's advanced nuclear complexes (especially that at Kalpakkam) might have allowed India to develop the 100 MWt reactor without Russian help. 

Another INS Aridhaman image (courtesy Defense News).

Ghalib Kabir and Pete


Nicky K.D Chaleunphone said...

Hi pete,
I am shocked that Russia didn't offer to give them the design of the Delta-class submarine. It would fit India very well.

GhalibKabir said...

Thanks for the credit Pete. Some more points for interested people,

1. The imminent launch has been a strong rumor since April 2017 at least (not surprising considering the construction work since 2011). I would wager that the 'proper' launch is likely in early 2018 with sea trials by early 2020 and commission by late 2021.

2. I hope they stick to the 8 VLS 3,500 km range K-4 SLBM layout. The K-15 has no value any longer. I am also hearing that the K-5 SLBMs might have 3 MIRVs per missile, so initially the K-4 missiles might carry a single warhead only (like a Pu boosted fission device)

See page 5 of 6:

3. The VM reactor: It was the VM-5 used on the 661 class SSNs that formed the test bed 83 MWt reactor near Chennai (till the assistance allegedly stopped in 2015-16) and probably formed the basis for some improvement by India on its own to uprate the Aridhaman.

According to Indian scientists more than 'Know-how' it was Russian 'Show-how' that was more useful. I think thats the key here. to be 'showed how' makes for the actual breakthrough.

See Page 135 of this book:

Peter Coates said...

Hi Ghalib Kabir

Thanks for the extra information in your Comment of 31/8/17 11:29AM at Points 2. and 3.

I'll use that information
and information on Indian SSBNs and SLBMs at pages 130 to 138 of long (20MB) US OPEN SOURCE source intelligence PDF file
for an article tomorrow (1 Sept)



Nicky K.D Chaleunphone said...

HI Pete,

You may want to take a look at this

Saab Expands its A26 Submarine Offer with now Three Variants to Choose From

Peter Coates said...

Thanks Nicky K.D Chaleunphone [at 1/9/17 3:26 AM]
is an interesting description of two A26 concepts and the baseline 2,000 t (surfaced) A26 that the Swedish Navy is buying.

Saab's claim that the A26 is unique due to its modularity has been preempted for years by the multi-sized TKMS Type 209s, the Type 214 vs 218, and the Dolphin 1 vs Dolphin 2.