INS Arihant (ATV) News and Discussion -2

merlin · Post by **merlin** » 02 Jun 2010 17:12

Gagan wrote:No no, the lighting inside the yard is like this onlee (As in we are like this onlee)
The image itself published by shiv aroor was probably a smaller image, which has been resized to a larger size, hence a lot of pixelization on the image.
I wonder if the photographer did a white balance of his camera to adjust for the sodium vapour lamps inside the yard.
Perhaps this has been taken from a consumer digicam, not a professional digital SLR?

IIRC cameras were not allowed inside. This one looks like a low end cell phone camera image upsized by quite a bit.

dinesha · Post by **dinesha** » 02 Jun 2010 17:23

No point discussing about the pic quality, lighting, camera etc..
Navy has released this picture to reveal as much as they want to reveal.. lot of thought, scuritiny and analysis might have been carried out before releasing this photo..

vardhank · Post by **vardhank** » 02 Jun 2010 17:32

Gagan, just one change I think you might make to your last illo... the upward/rearward curve from the sonar dome to the hump (whatever there is of it) ends at the front part of the sail, not behind the sail... i think the 'hump' flattens out (the line goes horizontal) from there already, so the sail is a perfect oblong, without a slanted line across the bottom.
Awesome job!

dinesha · Post by **dinesha** » 02 Jun 2010 18:05

Following is 1:1 scan of Arihant from the UPA report card.. it is not pixeleted hence some of the details are more prominent

For complete UPA-II report.. Arihant photo is under the "Security" section
http://pmindia.nic.in/english_report_01.06.10.pdf

tsarkar · Post by **tsarkar** » 02 Jun 2010 18:10

No vardhank, read my earlier post, it is indeed inclined from dome till hump.

nash · Post by **nash** » 02 Jun 2010 18:54

i am not the expert but after seeing gagan's last picture it look like very similar to graney class...

dimension and displacement is also very similar.

Singha · Post by **Singha** » 02 Jun 2010 19:46

yuk yuk yankee class http://perch-base.org/Glossary/Graphics ... marine.jpg

I think its most similar to yankee class among RuN subs.

in rough LOOKS only ofcourse and a better shaping on exterior.

abhijitm · Post by **abhijitm** » 02 Jun 2010 20:25

From outside it looks like a Los Angeles class SS to me.

More like an Ohio Class SSBN.

Looks like Amur

Yep Kilo family indeed

yuk yuk yankee class

To me it looks like an Arihant class submarine.

heard of some wet pants turning brown across the border...

Anoop. A. · Post by **Anoop. A.** » 02 Jun 2010 20:38

abhijitm wrote:To me it looks like an Arihant class submarine.

and really proud to call it our own....

abhijitm wrote:heard of some wet pants turning brown across the border...

Nice...

i couldnt have said it any better...

Misraji · Post by **Misraji** » 02 Jun 2010 21:32

Singha wrote:yuk yuk yankee class http://perch-base.org/Glossary/Graphics ... marine.jpg
I think its most similar to yankee class among RuN subs.
in rough LOOKS only ofcourse and a better shaping on exterior.

The best comparison done so far in terms of displacement and goals.
Yankee could be labelled as baby-boomer too. Built to be an SSBN with the performance of an SSN.

The technology at that time permitted only short-range ballistic missiles and
an unreliable reactor. But that should not be a problem now.

For the Arihant, its the acoustics that might be a problem given that we have a reactor inside a relatively small hull.
Though its not the Rubis class and thus the problem does not lie with the basic concept.

~Ashish

Hiten · Post by **Hiten** » 02 Jun 2010 22:16

the as-is size as extracted from the PDF document is slightly bigger

The "hump" turned out to be an interplay between a rope and the sun coupled with a shoddy camera work [possibly deliberate]
Torpedo tube doors visible above waterline

bhavani · Post by **bhavani** » 02 Jun 2010 22:50

Singha sir,

I agree it looks a bit similar to the yankee class. The yankee had a displacement of 7500 tons.

The yankee notch 667AT yankee notch was a modification of original to fire the SS-N-21 and SS-N-24 cruise missiles.

http://www.fas.org/nuke/guide/russia/sl ... 42_JPG.jpg

http://www.fas.org/nuke/guide/russia/slbm/667a_05.jpg

One really good thing i see about arihant is absence of flood holes.

Misraji · Post by **Misraji** » 02 Jun 2010 23:02

Gagan wrote:I had drawn one drawing like that for the arihant, essentially it starts to slope forwards from the missile tubes all the way to the sonar up front, and then drops into a smooth curve.
And there is likely another smooth curve aft of the missile tubes until it meets the aft section of the sub.

Gagan saar, you have depicted the hump(if you can call it that) as extending considerably behind the sail.
Almost with similar relative dimensions to any SSBN.

However, isn't the Arihant supposed to be armed with only 4 full-dia missile tubes.
So maybe the hump should not extend significantly behind the sail.

~Ashish

ramana · Post by **ramana** » 02 Jun 2010 23:31

It looks like the Arihant class. PERIOD.

Gagan · Post by **Gagan** » 03 Jun 2010 01:07

Misraji wrote:Gagan saar, you have depicted the hump(if you can call it that) as extending considerably behind the sail.
Almost with similar relative dimensions to any SSBN.

However, isn't the Arihant supposed to be armed with only 4 full-dia missile tubes.
So maybe the hump should not extend significantly behind the sail.

~Ashish

I don't know. I haven't actually seen the sub. This is more like an educated guess, or like 'a blind man trying to describe the elephant'

I still wonder, what's the need to be so secretive about a sub's outer shape? The real stuff is inside. GoI should release some good quality photos of the submarine. Not releasing the photos is more of a political decision, I guess 'out of sight, out of mind' thing applies here.

Gagan · Post by **Gagan** » 03 Jun 2010 01:27

tsarkar wrote:Gagan, your last picture is it.

Thanks for the tips tsarkar garu.

asprinzl · Post by **asprinzl** » 03 Jun 2010 07:20

Lots of distortions in the picture that was released. The people at the helm of UPA are not stupid. I am sure they must have sat with the IN brass and hammered out how to release and what to cover up.
One deception that is clear as daylight is the finish on the hull. It looks massively banged up or sloppily done. From the picture it looks like it is fodder for sonar. Come on. Do you really think that a force that can built a stealth ship like Shivalik is gonna produce a strategic platform like that?
I doubt if that is even the real Arihant. Probably the real Arihant is somewhere underwater still undergoing trials/tests while a mock-up or a well done photoshop ploy.
Avram

Singha · Post by **Singha** » 03 Jun 2010 07:52

what is the function of the drain holes in Jin class?
even U-boats had them.
http://www.fallingpixel.com/products/93 ... er%201.jpg

vavinash · Post by **vavinash** » 03 Jun 2010 08:30

If there is a factory recall on the reactor or other parts they can row it back to port.

Singha · Post by **Singha** » 03 Jun 2010 08:46

even delta class has it
http://upload.wikimedia.org/wikipedia/c ... rine_2.jpg
typhoon does not
http://www.military-today.com/navy/typhoon_class.jpg
borei does not
http://www.military-today.com/navy/borei_class.jpg
vanguard does not
http://www.fas.org/nuke/guide/uk/slbm/V ... 052197.jpg
le troimphant does not
http://www.webinfrance.com/wp-content/u ... rrible.png
and not the ohio
http://www.naval-technology.com/project ... /ohio2.jpg

Gagan · Post by **Gagan** » 03 Jun 2010 08:51

Avram,
That uneven surface that you see on the sub is due to the anechoic tiles pasted on the surface of the sub.

These are made of special rubber like material, and are about a square foot or so in size. These are then pasted on the surface of the outer hull of the submarine. Their purpose is to further reduce noise produced from within the submarine from coming out.

The americans initially laughed at the soviets for putting these on their subs. But today, nearly every sub manufacturer seems to be doing this., even the americans.

Vavinash,
The reactor is tested on the ground before the reactor section is welded into the submarine. Unless some major event occurs, naval reactors don't usually need to be majorly overhauled. The one on the Arihant needs refuelling with new fuel rods every 10 years or so, and for that the submarine will come into the dry dock, the reactor compartment will be cut aside, and the reactor removed, serviced and replaced. The option is to refuel the rods in the reactor, perhaps this can be done without cutting open the sub.
Depends on which design philosophy BARC adopted - A fully sealed reactor that needs replacement when the fuel runs out (requiring the reactor to be removed from the sub by cutting it up), or a reactor where fuel rods only can be replaced.

chackojoseph · Post by **chackojoseph** » 03 Jun 2010 12:17

What is the chance that its an SSN onleee? IIRC in 1990's the plan was 3 SSN's initially and 2 SSBN's. I don't see any humps on the sub.

tsarkar · Post by **tsarkar** » 03 Jun 2010 12:37

Not expecting this question from you, Chacko, of all people

From the horse’s mouth - http://www.hindustantimes.com/Arihant-t ... 09620.aspx

Philip · Post by **Philip** » 03 Jun 2010 12:41

Don't forget that after the missile silos comes the reactor compartment,which would also require a hull diameter of similar size,as the missiles on the ATV are not of ICBM size.where either the hull is even larger in size or a distinctive hump is featured.So extending the hull in plane form after the missiles explains why Gagan's drg. is so.There was also another sketch by a service officer afer the launch in the F-mag.Again slightly fudged but quite similar.

As for the SSGNs in the future,from the tiny drg. in an old issue of the F-mag,the 3+ SSGNs following on appear to be quite similar.

chackojoseph · Post by **chackojoseph** » 03 Jun 2010 13:01

tsarkar wrote:Not expecting this question from you, Chacko, of all people

From the horse’s mouth - http://www.hindustantimes.com/Arihant-t ... 09620.aspx

Things I ask to get stuff verified from my sources is even worse. Thanks for that and I have seen that.

Philip wrote:Don't forget that after the missile silos comes the reactor compartment,which would also require a hull diameter of similar size,as the missiles on the ATV are not of ICBM size.where either the hull is even larger in size or a distinctive hump is featured.So extending the hull in plane form after the missiles explains why Gagan's drg. is so.There was also another sketch by a service officer afer the launch in the F-mag.Again slightly fudged but quite similar.

As for the SSGNs in the future,from the tiny drg. in an old issue of the F-mag,the 3+ SSGNs following on appear to be quite similar.

See I too have similar info. But, I had this nagging feeling to ask. Especially the hump on Gagan's drawing started to shrink.
Journos had mentioned seeing an hump. Why is the hump not there now?

Added later....

IMO most people who saw the sub had appreciated the earlier photo by Gagan.

Austin · Post by **Austin** » 03 Jun 2010 14:00

Singha wrote:vanguard does not
http://www.fas.org/nuke/guide/uk/slbm/V ... 052197.jpg

There is good deal of Ingenuity in British Sub design both the Vanguard and the Astute have very unconventional design , they did not choose the tried and tested Albacore type we see in Western subs i.e US subs even very modern ones and the French types.

Singha · Post by **Singha** » 03 Jun 2010 14:13

the only other modern subs (non british) with that look of sail and tallboy hull design is the HDW U212 series.
http://airalex.homestead.com/files/U_212.jpg

the british-germans may have done some R&D together perhaps? or one stole / cloned from the other but U212, Astute SSN and vanguard SSBN feature the same look.

the older british trafalgar class / swiftsure class had the conventional look
http://www.royalnavy.mod.uk/operations- ... hms-torbay

looking at astute cutaway, the ballast tanks seem to be along the top of the ship accounting for its tall hull outside
the water. and it doesnt feature the house sized spherical bow sonar of the LA/nssn/seawolf class unless the drawing
is deliberately misleading. if its sphercial, is much smaller than the LA sphere.

http://www.royalnavy.mod.uk/upload/pdf/ ... _image.pdf

this slide indicates the thales 2076 in astute is a cylinder shaped, which fits in with the nose shape.
http://aviationweek.typepad.com/photos/ ... lide_2.png

the american sphere shape may not be the last word

Anshul · Post by **Anshul** » 03 Jun 2010 14:41

Some more Photoshopping.Front portion of the hull clearly reveals 2 torp tubes.Could't get it to do any more magic.
http://img707.imageshack.us/img707/6223/insarihant.png

Kersi D · Post by **Kersi D** » 03 Jun 2010 17:13

abhijitm wrote:
From outside it looks like a Los Angeles class SS to me.

More like an Ohio Class SSBN.

Looks like Amur

Yep Kilo family indeed

yuk yuk yankee class
To me it looks like an Arihant class submarine.
heard of some wet pants turning brown across the border...

Reminds me of our old school story of blond men and an elephant. One blindman feels the tail says the elephant is like a rope, another blindman feels the trunk says the elephant is like a snake. Perhaps we all are groping in the dark.

I only hope in gives wet pants to our neighbours in the west and east and ...

K

Austin · Post by **Austin** » 03 Jun 2010 17:41

Singha wrote:the british-germans may have done some R&D together perhaps? or one stole / cloned from the other but U212, Astute SSN and vanguard SSBN feature the same look.

Hmm not possible , Submarine technology specially Nuke submarine technology are jealously guarded by each country , even munna and khan do not share much in those area. Most countries have their own unique design based on their own R&D in those areas.

The Germans have their own unique sub design and can be attributed to their own R&D.

Yes Astute do have some attribute of Vanguard but the next gen of SSBN from Brits 3 such have been planned will derive greatly from Astute design to save on R&D cost associated with new SSBN design , hence the next gen of SSBN will have much more similarity to Astute design.

There are sub conference held time to time where informal exchange of ideas within Naval submarine communities take place. IMO the Vanguard and Borei design stand apart from the crowd.

the american sphere shape may not be the last word

American sub is as much about hype as about substance , a Russian Admiral was quoted as saying that facing British Submarine was much difficult challenge then American ones.

Aditya_V · Post by **Aditya_V** » 03 Jun 2010 17:54

Austin_ > Nuke technology MTCR is only applicable to SDRE's. Without American missiles and parts, Britain wont have nucler subs. Similarly look at how America, Australia and the WEST are turning away from the NPT, MTCR, NSG has been made defunct by China's transfers to Pakis. It seems all these rules apply to India only.

Gagan · Post by **Gagan** » 03 Jun 2010 18:34

Here is the latest rendition of the ATV: (click for larger image)

This is what the Journalists saw:

And this is the full sub:

chackojoseph, tsarkar, Austin, Philip, saars please give your feedback. Is this what its like?

negi · Post by **negi** » 03 Jun 2010 19:33

Austin wrote: American sub is as much about hype as about substance , a Russian Admiral was quoted as saying that facing British Submarine was much difficult challenge then American ones.

Austin bhai has to conclude with a boot up the Unkil's behind .

bhavani · Post by **bhavani** » 03 Jun 2010 19:35

Singha wrote:even delta class has it
http://upload.wikimedia.org/wikipedia/c ... rine_2.jpg
typhoon does not
http://www.military-today.com/navy/typhoon_class.jpg
borei does not
http://www.military-today.com/navy/borei_class.jpg
vanguard does not
http://www.fas.org/nuke/guide/uk/slbm/V ... 052197.jpg
le troimphant does not
http://www.webinfrance.com/wp-content/u ... rrible.png
and not the ohio
http://www.naval-technology.com/project ... /ohio2.jpg

Flood holes are present on the casing of the submarine and allow free flooding and allowing water to enter freely and trapped air to escape.

But flood holes increase noise and hydrodynamic drag. so the new submarines are doing away with the flood holes. Some boats like akula have a few still left.

More the number of drainage holes, More the noise. For Ex the 094 class of china has around 100 flood holes and in fact has the noise signature of a 1960 soviet SSBN. The chinese 093 SSn also has more noise than a 1970's Victor class.

http://www.armscontrolwonk.com/1579/how ... the-094-23

In the Arihant picture it is great that we don't see any flood holes till now. I hope it does not have any.

tsarkar · Post by **tsarkar** » 03 Jun 2010 19:58

Gagan, the incline from bow to missile launchers is gentle and uniform. I see inclination angle increase halfway from the sail, which is not the case. You have got the other parts quite accurate.

Added later - Also reduce the height of the missile deck by a milimeter. The hump is not prominent. It is diffused with the hull, like a belouga whale. http://en.wikipedia.org/wiki/File:Beluga_size.svg

Though the hump can be discerned. I suggest reducing height by one mm will have the desired results.

chackojoseph · Post by **chackojoseph** » 03 Jun 2010 20:03

Gagan,

The area immediate behind the conning is a concave surface. Its not light reflection issue IMHO, to start with.

Gagan · Post by **Gagan** » 03 Jun 2010 20:29

I thought so too, that looks concave, so I've put in that concavity there.

The closest representation is the Amur design with the Brahmos VLS tubes.
http://www.acig.org/artman/uploads/amur2.jpg

chackojoseph · Post by **chackojoseph** » 03 Jun 2010 20:38

I frankly don't see anything concave behind the conning in Amur. As I see, the conning is in the middle of a concave. But, in Arihant, the concavity starts after the conning. The front portion of Arihant is Half convex till the conning. The conning stands between the two focal surfaces.

Austin · Post by **Austin** » 03 Jun 2010 21:06

Aditya_V wrote:Austin_ > Nuke technology MTCR is only applicable to SDRE's. Without American missiles and parts, Britain wont have nucler subs. Similarly look at how America, Australia and the WEST are turning away from the NPT, MTCR, NSG has been made defunct by China's transfers to Pakis. It seems all these rules apply to India only.

Aditya_V I was referring about Nuke Sub Technology and the Sub itself ( Not NPT and MTCR ) its true UK subs uses US SLBM D-5 and US has helped them in validating their Nuke warhead , as far as Sub technology goes ( Design ,Reactor ,Sonars , C&C etc ) they are all developed by UK and thats equally true for all countries.

I think the concaveness is more smoother/streamlined for ATV compared to Amur because ATV is a larger/longer sub, the Amur under scanner is the smallest in all the Amur class family "Amur-950" hence the concave is quite apparent , steeper and shorter due to its size.

SNaik · Post by **SNaik** » 03 Jun 2010 21:11

Gagan, it seems that the bow part between the sonar cover and conn has some kind of narrow superstructure. So, there's a uniform rise from bow to hump, but on top of that uniform rise is a superstructure which provides for level deck in front of conn.
I'd also consider putting a sonar cover below torps, like in Kilo. It's highly unlikely that the sub is designed just with navigation sonar.