INS Arihant (ATV) News and Discussion -2

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Re: INS Arihant (ATV) News and Discussion -2

Postby Singha » 27 Jun 2018 07:48

Spherical sonar of a early virginia or late 688i

Is that chamber a air cavity or flooded at sea pressure?

http://www.mdc.idv.tw/mdc/navy/usanavy/E-Sonar2.htm

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Re: INS Arihant (ATV) News and Discussion -2

Postby Singha » 27 Jun 2018 07:51

Look at the last small pic also in above link
The spherical one is like a 2 storey building
There is a smaller one below perhaps to detect bottom mines or some other reason

Just gathering raw data is not enough one needs the compute resources onboard to use it in real time .

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Re: INS Arihant (ATV) News and Discussion -2

Postby Dileep » 27 Jun 2018 10:40

I can confirm that the hydrophone array is totally exposed to water. The cables connecting them are rated for the maximum depth, and enter the pressure hull via special connectors. The processing happens in racks inside the pressure hull.

What deep water pressure can do to material is phenomenal.

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Re: INS Arihant (ATV) News and Discussion -2

Postby prasannasimha » 27 Jun 2018 10:55

By its very definition the sonar or ultrasound transducer has to have no air fluid interface ( this is a limitation for eg in medicsl ultrasound and is also used to advantage in lung ultrasound ). The processing etc can be isolated obviously

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Re: INS Arihant (ATV) News and Discussion -2

Postby Dileep » 27 Jun 2018 11:05

In some of the applications, it goes Transducer->Some special Fluid->Solid Barrier->Sea Water. No air can be in the path in any case.

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Re: INS Arihant (ATV) News and Discussion -2

Postby JTull » 27 Jun 2018 13:10

So, when they say Chakra sonar dome was damaged, it means the actual hydrophone was damaged, and not some sort of hull casing?

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Re: INS Arihant (ATV) News and Discussion -2

Postby Singha » 27 Jun 2018 13:25

prasannasimha wrote:By its very definition the sonar or ultrasound transducer has to have no air fluid interface ( this is a limitation for eg in medicsl ultrasound and is also used to advantage in lung ultrasound ). The processing etc can be isolated obviously


thats why they put a KY jelly thing on the body when using that hand held sonar stick.

glad to have my submarine design theory validated.

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Re: INS Arihant (ATV) News and Discussion -2

Postby Singha » 27 Jun 2018 13:27

is the hull casing around the sonar made of composite rubber coated material or its just the submarine hull steel material? like the quartz radome thing on a fighter, it needs to pass through wideband sound cleanly without distortions or reflections. the interior buckhead and inside of the bow chamber is probably coated with anechoic material...so the sonar is a special huge "ear" placed in a water filled room with zero disturbance whose sole job is to listen keenly and feed raw signal back to the racks of processors and signal libraries. the quality of components would probably make bang n olufsen kit feel like walmart sale stuff.

if the pressure is equalized they could put a sheet of plastic and it would be fine I think. thats how very frail looking creatures live in the deep sea, and even certain larger animals like weddel seals and beaked whales dive 1 mile deep and feeding and hunting there for a hour. :-o fishes have superb systems for blood pressure & thermal profile management and absorbing O2 via flowing water through the gills and ballast tanks to manage their diving and buoyancy needs, all highly automated via evolution. one should study fishes, they are amazing creatures. they are also able to manage the light distortion and pressure of the water on their eyes.

a whale or shark would put a virginia/yasen class to shame in their highly integrated sensors and attack suite

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Re: INS Arihant (ATV) News and Discussion -2

Postby Singha » 27 Jun 2018 13:34

JTull wrote:So, when they say Chakra sonar dome was damaged, it means the actual hydrophone was damaged, and not some sort of hull casing?


the front dome would at best be soft metal or composite and would crumple .... the chakra might have ended up looking like that LA class sub I posted.

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Re: INS Arihant (ATV) News and Discussion -2

Postby prasannasimha » 27 Jun 2018 22:17

Or the hull may ahve a material with minimal transmission loss. (Same ultrsound jelly principle) Not sure what they do in a Submarine but the front bulbous end is mettallic for eg in Scorpene. They may be having some trasnducer ports just likd Flush air data systems look

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Re: INS Arihant (ATV) News and Discussion -2

Postby dinesha » 27 Jun 2018 22:47

This video shows the layout of DRDO developed USHUS-2 and other components of NPOL Sonar Suit comprising of a Passive, Active, Intercept and Obstacle avoidance Sonar. Probably same layout is employed is Arihant Class..



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Re: INS Arihant (ATV) News and Discussion -2

Postby Singha » 28 Jun 2018 09:30

the smaller active sonars on the nose and sail are for mine and obstacle avoiding, they are high frequency(good discrimination , short range) I think and mirror that on SSNs. the big one is mostly used in passive mode for locating targets and are the eye and ear.

we are getting there. all it lacks is a flank array (thales on scorpene has that)

its probably a lot better than the default OEM kit on the kilo class.

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Re: INS Arihant (ATV) News and Discussion -2

Postby Singha » 28 Jun 2018 09:36

what they label as intercept array on the sail of kilo and atlasE brochure below is mounted as a protruding horn on the foredeck of UK sub designs since mid 70s - its called parris or something like that. I am not sure what its use for other than navigating mined areas

Image

on the astute class its further forward
Image

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Re: INS Arihant (ATV) News and Discussion -2

Postby Singha » 28 Jun 2018 09:51

evolution always finds a way ...

Image
Image
Image
Image

Image

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Re: INS Arihant (ATV) News and Discussion -2

Postby Singha » 28 Jun 2018 09:55

the sharks sensor grid and level of integrated combat system puts a virginia ssn to shame.
coupled with its speed, strength and tactical acumen (attacks from below) it is a force of nature and apex predator.

dolphin is equipped with good sonar but not near the sharks 360' spherical attack suite :D

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Re: INS Arihant (ATV) News and Discussion -2

Postby Karthik S » 28 Jun 2018 10:24

Singha wrote:the sharks sensor grid and level of integrated combat system puts a virginia ssn to shame.
coupled with its speed, strength and tactical acumen (attacks from below) it is a force of nature and apex predator.

dolphin is equipped with good sonar but not near the sharks 360' spherical attack suite :D


Well, that title goes to orcas. Have you seen the video where the orcas hold a GREAT WHITE (of all sharks) upside down to induce tonic immobility? After orcas feasted on the great white, all other great whites fled the area.
It's about knowing your opponents' weakness and forming strategy to use that weakness.

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Re: INS Arihant (ATV) News and Discussion -2

Postby barath_s » 11 Jul 2018 12:53

Dileep wrote:I can confirm that the hydrophone array is totally exposed to water. The cables connecting them are rated for the maximum depth, and enter the pressure hull via special connectors. .


In block III virginiaclass, the passive bow sonar is modified so the individual cables no longer penetrate the pressure hull (water backed vs air backed). Fewer pressure hull penetrations makes for better safety(SUBSAFE).In any case, the hydrophone array is always exposed to water, see this foxtrot thread pics

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Re: INS Arihant (ATV) News and Discussion -2

Postby sum » 20 Aug 2018 05:25

X-post:
sum wrote:Lungi Dance time!!!!!!!!!!

First home-grown submarine launched, missile operationalised after 2 decades of development

Kept under wraps for several years and inducted in the Navy a couple of months ago, the SLBM, code-named B-05 was secretly test fired back-to-back from indigenously built nuclear-powered submarine INS Arihant off Visakhapatnam coast on August 11 and 12.

An official associated with the mission on Sunday told 'The Express' that three rounds of the world-class missile were tested during the first phase user trial and it was a roaring success. While two tests were conducted on August 11, one was put under trial the next day in full operational configuration.

"All three missiles were fired from the submarine positioned nearly 20-meter deep inside the sea, about 10-km off the Vizag coast. It perfectly followed the pre-designated trajectory before zeroing on the target with high accuracy reaching close to zero circular error probability,-" the official confirmed over phone from New Delhi.

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Re: INS Arihant (ATV) News and Discussion -2

Postby Singha » 20 Aug 2018 08:54

the birth of a new order ....

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Re: INS Arihant (ATV) News and Discussion -2

Postby prasannasimha » 20 Aug 2018 09:35

If B-05 was tested thrice thn guess that K4 would have also been tested.

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Re: INS Arihant (ATV) News and Discussion -2

Postby sum » 20 Aug 2018 09:52

Was there any NOTAM for these 3 tests?

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Re: INS Arihant (ATV) News and Discussion -2

Postby Singha » 20 Aug 2018 10:40

there is none logged here or in AAI sites i checked
http://www.hydrobharat.nic.in/downloads ... _force.pdf

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Re: INS Arihant (ATV) News and Discussion -2

Postby Indranil » 20 Aug 2018 11:55

Kurup did. He also guessed the missile right. But we expected it to be from a pontoon. Details on missile thread.

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Re: INS Arihant (ATV) News and Discussion -2

Postby sum » 20 Aug 2018 12:07

^^ Agree. I now remember that even a article ( mostly from HK Rout) mentioned that a pontoon launch was lined up and there were failures of previous 2 attempts.

It seems that the curtain is now being revealed that they all went through well and were from Arihant itself ( and not a pontoon) and were just willful disinformation fed to media

Edit:

Found the report:
India is preparing to conduct a crucial trial of its most ambitious submarine-launched ballistic missile (SLBM) from an underwater platform. Defence sources said the nuke-capable missile is likely to be test-fired from a pontoon (replica of a submarine) nearly 20 metre under the sea off Vizag coast on Thursday. While notice to airmen (Notam) has been issued, defence scientists are leaving no stone unturned for a successful mission as two consecutive attempts to launch the missile recently had reportedly failed.

Though earlier it was planned to test-fire the SLBM from indigenously-built nuclear-powered submarine INS Arihant, sources said the missile will now be fired from the pontoon as the submarine is not ready for live trials. :P “Elaborate preparations are on for the mission. The missile is ready while logistic arrangements are being put in place along with positioning of tracking systems. The test window has been kept for August 9, 10 and 11,” said a defence official.

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Re: INS Arihant (ATV) News and Discussion -2

Postby Philip » 20 Aug 2018 13:15

This validates submerged firing of BMs for our SSBNs.A huge milestone.Our sub-based leg of the nuclear triad has taken off. In future it will be the range and accuracy of the improved missiles,some on larger SSBNs planned that will be tested.Successfully inducting the first BM was the tough part.

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Re: INS Arihant (ATV) News and Discussion -2

Postby Prasad » 20 Aug 2018 13:29

Oooh now I want a SLBM launch video like those of our Agni. K-4 test would be next I suppose, if it hasn't been tested already that is.

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Re: INS Arihant (ATV) News and Discussion -2

Postby ks_sachin » 20 Aug 2018 14:19

Singha wrote:the birth of a new order ....

First lets get some decent assault rifles for the boys. Then world order...

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Re: INS Arihant (ATV) News and Discussion -2

Postby RKumar » 20 Aug 2018 14:22

Prasad wrote:Oooh now I want a SLBM launch video like those of our Agni. K-4 test would be next I suppose, if it hasn't been tested already that is.


Are you from AAP or Congress party :rotfl:? It will be out in due course, not just yet - let's wait for a few years. At least till we have longer-range missiles operational along with additional ATVs.

ABV left this world only after knowing that Triad is in place and his started work is completed.

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Re: INS Arihant (ATV) News and Discussion -2

Postby arshyam » 20 Aug 2018 19:52

^^ Well said. ABV's work is done, securing India for good.

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Re: INS Arihant (ATV) News and Discussion -2

Postby Prasad » 20 Aug 2018 21:30

RKumar wrote:
Prasad wrote:Oooh now I want a SLBM launch video like those of our Agni. K-4 test would be next I suppose, if it hasn't been tested already that is.


Are you from AAP or Congress party :rotfl:? It will be out in due course, not just yet - let's wait for a few years. At least till we have longer-range missiles operational along with additional ATVs.

ABV left this world only after knowing that Triad is in place and his started work is completed.

Not to cast doubts man. To loop it and watch it a few thousand times onlee.

Cannot imagine the number of points that a successful test like this ticks off. Would have proven many many things. Safe launch, behaviour of the submarine in the water, stability etc etc.

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Re: INS Arihant (ATV) News and Discussion -2

Postby kit » 20 Aug 2018 22:51

A salvo of mirv tipped sea-launched ballistic missiles can literally bring down any nation on earth !

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Re: INS Arihant (ATV) News and Discussion -2

Postby Singha » 20 Aug 2018 23:00

Without k4 and arighat aridaman 8 tube loadouts all is maya

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Re: INS Arihant (ATV) News and Discussion -2

Postby prasannasimha » 20 Aug 2018 23:23

^ without deployment of BO5 there would have been no K4

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Re: INS Arihant (ATV) News and Discussion -2

Postby Cain Marko » 21 Aug 2018 06:01

When is the follow on, arighat? being put to sea

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Re: INS Arihant (ATV) News and Discussion -2

Postby Aditya_V » 21 Aug 2018 07:07

We don t know the status of INS Arindham and INS Arighat .One of these is facing acceptance trials
Last edited by Aditya_V on 21 Aug 2018 10:20, edited 1 time in total.

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Re: INS Arihant (ATV) News and Discussion -2

Postby Singha » 21 Aug 2018 07:53

arihant will keep on proving technologies and tactics for the follow on subs to use.
it will turn out to be the most influential sub in our history like uss nautilus and uss albacore and serve for a long time.

#margdarshak - the pathfinder

the real "red in tooth and claw" deal will put to sea in arighat and aridaman to start with.

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Re: INS Arihant (ATV) News and Discussion -2

Postby Katare » 21 Aug 2018 19:52

Did any other news organization reported the news?

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Re: INS Arihant (ATV) News and Discussion -2

Postby SaiK » 30 Aug 2018 17:09

Is there a INS Vishal dhaaga?

Quick Q: is it home grown or import project? I'm confused after reading S Jha srticle.

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Re: INS Arihant (ATV) News and Discussion -2

Postby Rakesh » 31 Aug 2018 06:04

Time for a new thread....


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