January 15, 2018

INS Arihant's Temporary Sinking Explains Arighat's Launch & Aridhaman's Delay

It seems the Indian Navy and broader government thought it wise to launch INS Arighat on November 19, 2017 in the then secret knowledge that INS Arihant has sunk at its moorings during a test in February 2017. The Arighat (very similar to Arihant in size and design) launch can be seen as a means of deflecting the political embarrassment and recriminations of the Arihant sinking.

INS Arihant.
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Arihant sank at India's major east coast naval base of Visakhapatnam . The cause - allegedly a hatch left open during an Arihant submersion test.

Given the apparent lack of such a hatch on Arihant (reports India's Economic Times, Jan 12, 2018) and likelihood of sensors to avoid major accidents the official "hatch left open" explanation seems suspicious. Maybe instead, sabotage by a disgruntled or bribed crewman or technician? Even Chinese or Pakistani agent involvement?

India's Visakhapatnam east coast naval base. Naval vessels can be seen halfway up the harbour. This is to the right of what looks like the submarine repair and SLBM loading shed that INS Arihant will need to use, or is already under repair at. 
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Repairing, or if need be, replacing Arihant's reactor is likely to be a Billion dollar exercise. Involving Arihant being placed in drydock, moved to Visakhapatnam repair shed then being vertically cut open, basically in half.

The Arihant accident not only involves major repair costs but delays India's SSBN and broader indigenous nuclear submarine technical modification/learning program. It also delays training of the  officers and crew who will transition to a full size Aridhaman SSBN around 2020(?).

Compounding the problems is subsequent damage to India's other nuclear submarine, INS Chakra, in early October 2017. Russian built Chakra (ex Nerpa) has been 10 year leased to India. Chakra is used by India as a training platform and technology transfer (including its nuclear reactor) asset.

In fact these negative impacts (repair cost, technical improvements and training program) of the Arihant accident may have delayed Aridhaman's launch by a year or two.

Pete

6 comments:

Parth said...

1.Aridhaman was renamed to Arighat- two names, same boat.
2. Arihant was made operational by the time news surfaced (incident happened in 2016)

Peter Coates said...

Thanks Parth

On Aridhaman being renamed Arighat.

So when is India launching a true SSBN?
ie not a test boat like INS Arihant?

Regards

Pete

Parth said...

Hi, Arighat has already been launched. She will head out to sea trials next year.
Arighat(S-3) carries 8 K-4 and 24 K-15(Arihant- 4 K-4, 12 K-15), it is a fully fledged SSBN. S-3/S-4 are under construction.
A new class of SSBNs known as S-5 is under development. S-5 boats will be similar to French Tiomphant class in terms of displacement and armament.

Peter Coates said...

Hi Parth

Given Arihant and Arighat are both reputed to be 6,000 ton (surfaced) sister ships (each with an 83 MW reactor) the ability of Arighat to mount 8 x K4 sized vertical tubes compared to Arihant's 4 x K4 is truely impressive.

This must have involved many trade-offs?

Are you sure Arighat is only 6,000 ton surfaced or is it significantly larger than Arihant?

- with a 5 meter hull plug?

Regards

Pete

Parth said...

Arihant follow-on was supposed to be longer, heavier(~1000ton) and powered by an uprated reactor. Arihant turbine is powerful(it has to be because there is no other way to Arihant could reach 24kts) enough but it's the reactor that can't sustain high-speed dash.

Peter Coates said...

Hi Parth

Thanks for the extra info.

So I'm guessing Arighat (at approx 7,000 tons) would require a reactor of around 95MW and assume it has the same beam/diameter as Arihant?

Regards

Pete