Armoured Vehicles Discussion Thread

Austin
BRF Oldie
Posts: 23387
Joined: 23 Jul 2000 11:31

Re: Armoured Vehicles Discussion Thread

Postby Austin » 26 Apr 2010 12:04

I would assume the T-72/90 then cannot fire HESH round , is that a major disadvantage that comes along with T's ?

As far as rifled gun goes except for Chally , no other Western MBT has rifled gun all seem to have smooth bore as per DRDO chart in Ajai blog

As far as long rod goes there is a long rod ammo that T-90M can fire due to new autoloader as confirmed by d_berwal and a new gun as well that fires with higher muzzle velocity.

Anujan
Forum Moderator
Posts: 7007
Joined: 27 May 2007 03:55

Re: Armoured Vehicles Discussion Thread

Postby Anujan » 26 Apr 2010 12:11

Depends on the doctrine. HESH is considered to be the best for bunker busting. Unkil's combat engineer vehicle is designed to fire HESH and so is the Stryker with 105mm gun (itself a derivative of the centurion's gun). Bunker busting is done by these vehicles.

Austin
BRF Oldie
Posts: 23387
Joined: 23 Jul 2000 11:31

Re: Armoured Vehicles Discussion Thread

Postby Austin » 26 Apr 2010 14:16

^^^ Can HEAT round do the job of bunker busting equally well ?

Aditya_V
BRF Oldie
Posts: 12407
Joined: 05 Apr 2006 16:25

Re: Armoured Vehicles Discussion Thread

Postby Aditya_V » 26 Apr 2010 15:14

Regarding Avram-> I think given his Background he would have most probably served in the IDF as an infantryman along with Merkeva Tanks.

Surya
BRF Oldie
Posts: 5034
Joined: 05 Mar 2001 12:31

Re: Armoured Vehicles Discussion Thread

Postby Surya » 26 Apr 2010 15:28

I believe Avram served around the IDFs 1982 invasion of Lebanon.

aditp
BRFite
Posts: 447
Joined: 15 Jul 2008 07:25
Location: Autoland

Re: Armoured Vehicles Discussion Thread

Postby aditp » 26 Apr 2010 15:36

Austin wrote:^^^ Can HEAT round do the job of bunker busting equally well ?


Not sure, but possibly not. HEAT rounds work by generating an extremely high pressure but narrow stream of very high temp gas / plasma that punches a hole through the armour and cooks off the combustible stuff inside. Against a concrete barrier (read bunker) the hot stream after penetration through a neat small hole may find a very large empty volume of space inside and the rapid expansion may cool off the gas to a large extent. So although the blast damage would possibly still be significant, the round may not have the desired incendiary effect.

HESH on the other hand causes the plastic like explosive to spread on the bunker wall upon impact before being set off by the fuse. Surface detonation causes an extremely powerful mechanical vibration to pass through the structure. Generally the stress is well beyond the design limit, causing the structure to spall from inside if it is an armoured vehicle / collapse altogether if it is a concrete bunker.

Hence I believe HESH should be more effective against bunkers

SDRE Noobie dream onree, backed by some data as posted by Anujan

Rahul M
Forum Moderator
Posts: 17050
Joined: 17 Aug 2005 21:09
Location: Skies over BRFATA
Contact:

Re: Armoured Vehicles Discussion Thread

Postby Rahul M » 26 Apr 2010 18:05

Surya wrote:I believe Avram served around the IDFs 1982 invasion of Lebanon.

hmm, merk-I's that served in that war are supposed to have been the first in service tanks with ERA.

rohitvats
BR Mainsite Crew
Posts: 7734
Joined: 08 Sep 2005 18:24
Location: Jatland

Re: Armoured Vehicles Discussion Thread

Postby rohitvats » 26 Apr 2010 19:10

Viv S wrote:
Well maybe I've got my definitions wrong. I'm quoting Ajai Shukla here:-

When the first shots rang out as the tanks started zeroing, the crews came out and told the trial team that the LRFs were giving wonky ranges. Totally wonky. Like indicating 600 metres instead of 2400 metres. Switches were also tripping, for no accountable reason.


Well that doesn't sound like a calibration error to me(though I admit I could be wrong).


If you read the period mentioned in the Shukla Report about the tests and what I posted from the PSCD Report, it is obvious that it was caliberation issue.The PSCD Report explain this very incident.

Let me repost a section of excerpt that I had posted earlier from the PSCD Report -

<SNIP> What happens is that in the gun control system, there are power amplifiers which are used in the fire control system. Some temperature settings were not properly done by the parent company. These were tucked inside. As you know, now-a-days, the deck is packaged so densely even to get access to that you have to take out the whole module. So, when this type of settings get disturbed, the rule says that one has to go through the whole qualification process again. There is no change in the design. It is a temperature re-setting which was got done. That has been rectified. Now the tanks would be there by the middle of January

Viv S
BRF Oldie
Posts: 5303
Joined: 03 Jan 2010 00:46

Re: Armoured Vehicles Discussion Thread

Postby Viv S » 26 Apr 2010 20:39

rohitvats wrote:
If you read the period mentioned in the Shukla Report about the tests and what I posted from the PSCD Report, it is obvious that it was caliberation issue.The PSCD Report explain this very incident.

Let me repost a section of excerpt that I had posted earlier from the PSCD Report -

<SNIP> What happens is that in the gun control system, there are power amplifiers which are used in the fire control system. Some temperature settings were not properly done by the parent company. These were tucked inside. As you know, now-a-days, the deck is packaged so densely even to get access to that you have to take out the whole module. So, when this type of settings get disturbed, the rule says that one has to go through the whole qualification process again. There is no change in the design. It is a temperature re-setting which was got done. That has been rectified. Now the tanks would be there by the middle of January


:-o Hadn't read that before. Must have missed it. Would you mind posting the entire link. Cheers!

Its still guilty on the charge of miffing the brass, who had to sit the hot sun without any show put on.

chackojoseph
BRF Oldie
Posts: 4297
Joined: 01 Mar 2010 22:42
Location: From Frontier India
Contact:

Re: Armoured Vehicles Discussion Thread

Postby chackojoseph » 26 Apr 2010 20:52

Viv S wrote:Its still guilty on the charge of miffing the brass, who had to sit the hot sun without any show put on.


Army top brass is the most miffed category in the Armed forces. And no, they did not sit in the hot sun. They were also drinking "cold" lassi and munching nuts. Then they laughed and flew away in their choppers.

bhavik
BRFite -Trainee
Posts: 50
Joined: 26 Aug 2009 02:02

Re: Armoured Vehicles Discussion Thread

Postby bhavik » 26 Apr 2010 21:00

Rahul M wrote:
Surya wrote:I believe Avram served around the IDFs 1982 invasion of Lebanon.

hmm, merk-I's that served in that war are supposed to have been the first in service tanks with ERA.


I believe the drawbacks mentioned for ERA are still true even with new age ERA -
http://en.wikipedia.org/wiki/Reactive_a ... ive_armour
Also had seen this being described on a Discovery Channel Video.

Austin
BRF Oldie
Posts: 23387
Joined: 23 Jul 2000 11:31

Re: Armoured Vehicles Discussion Thread

Postby Austin » 26 Apr 2010 21:19

Thanks Anujan , Adip . Do they ever use HEAT or HESH rounds from tanks in indirect fire mode like they do with large caliber shell ( 155 mm etc ) to take out targets at long ranges than that possible via Direct Fire ?

Karan M
Forum Moderator
Posts: 19839
Joined: 19 Mar 2010 00:58

Re: Armoured Vehicles Discussion Thread

Postby Karan M » 26 Apr 2010 21:36

VivS: "So, the electronics were not in fact 'hardened' to operate in very hot conditions after the trial?"

No - they were meant to operate in very hot conditions before itself and the issue. Did even more ruggedization take place after the latest trials in the electronics, perhaps, improvements are part and parcel of the process. But the electronics performed well, and consistently even before that in high heat conditions. Hence the clearance was given for production and the program reached a stage where first five tanks were made, and were fitted with newly supplied systems direct from OEM which were improperly calibrated and hence failed.

Viv S
BRF Oldie
Posts: 5303
Joined: 03 Jan 2010 00:46

Re: Armoured Vehicles Discussion Thread

Postby Viv S » 26 Apr 2010 21:41

chackojoseph wrote:

Army top brass is the most miffed category in the Armed forces. And no, they did not sit in the hot sun. They were also drinking "cold" lassi and munching nuts. Then they laughed and flew away in their choppers.


Well it was still hot. How can you expect them to order the Arjun after putting them through such a harsh experience.


If indeed the tank was ready in 2005, CVRDE must have been frustrated as hell. I can almost imagine the next demo for the generals : CVRDE fellow whispering to gunner - 'aim for the generals' pavilion this time'.
Last edited by Viv S on 26 Apr 2010 21:49, edited 1 time in total.

aditp
BRFite
Posts: 447
Joined: 15 Jul 2008 07:25
Location: Autoland

Re: Armoured Vehicles Discussion Thread

Postby aditp » 26 Apr 2010 21:45

Viv S wrote:<snip>
Well it was still hot. How can you expect them to order the Arjun after putting them through such a harsh experience.


Is that a sarcasm :mrgreen: or a justification :eek: ?

Karan M
Forum Moderator
Posts: 19839
Joined: 19 Mar 2010 00:58

Re: Armoured Vehicles Discussion Thread

Postby Karan M » 26 Apr 2010 21:47

Austin wrote:As far as long rod goes there is a long rod ammo that T-90M can fire due to new autoloader as confirmed by d_berwal and a new gun as well that fires with higher muzzle velocity.


Again, there seems to be some confusion here and speculation. On asking a Russian gentleman aware of the T-90 program, as of yet there is no confirmation of any new autoloader in the latest Russian version of the T-90, maximum modification said to be made to the autoloader is that the arm feeding the round, tilts back so as not to hit the slightly longer FSAPDS on the breech of the gun. Also, muzzle velocity is misleading, one should look the velocity of the round, plus critical factors such as metallurgy. Why would T-90 require a higher muzzle velocity gun when the issue with the tank is one of ammunition.Also, the other improvements seem to be new form of ERA (explosive armour), and new sights and electronics. Long term, new engine is planned. It is not really any radical redesign of the tank and basic defects in terms of upgrade problems and ammunition storage remain.

Karan M
Forum Moderator
Posts: 19839
Joined: 19 Mar 2010 00:58

Re: Armoured Vehicles Discussion Thread

Postby Karan M » 26 Apr 2010 21:51

ViVS:"How come?"

Please read what Rohitvats has posted. How many times does one have to discuss/repeat the same thing, after all.

That is why I said this entire overheating business was being overhyped. This overheating business happened to a new batch of tanks brought out for a dog and pony show for the brass, which used systems calibrated for 50-55 deg versus 60 deg, whereas CVRDE people calibrated the trial tanks for 60 deg.

Viv S
BRF Oldie
Posts: 5303
Joined: 03 Jan 2010 00:46

Re: Armoured Vehicles Discussion Thread

Postby Viv S » 26 Apr 2010 21:53

aditp wrote:
Viv S wrote:<snip>
Well it was still hot. How can you expect them to order the Arjun after putting them through such a harsh experience.


Is that a sarcasm :mrgreen: or a justification :eek: ?


Hey they deserve a little comfort. Why do you think we're having air conditioners put in the T-90s? The brass does have to ride in them once in a while.

ArmenT
BR Mainsite Crew
Posts: 4239
Joined: 10 Sep 2007 05:57
Location: Loud, Proud, Ugly American

Re: Armoured Vehicles Discussion Thread

Postby ArmenT » 26 Apr 2010 21:55

Sanku wrote:Ok for Arjun, AFAIK, its not the electronics that themselves are hardened, but it is the tank design itself which ensures sufficient cooling (airflow, large spaces, special cooling?) for the electronics.

Basically a simple analogy would be, if you put a high end graphics processor in a lap top it will die, however in a large roomy desktop with a fan etc, it works well.

This was what JCage said if I am not wrong. Any opinions?

Bit of both actually. Some parts come in hardened versions that can tolerate wider temperature ranges, but cooling the environment around the board is needed as well. For example, consider the venerable IC 555 timer chip, beloved of electronics amateurs and professionals alike.
http://focus.ti.com/docs/prod/folders/print/se555.html
As you can see from the page, there are many versions of it. The datasheet lists 4 of them in a comparable format. The most common plastic version that you get at your local hobby store is the NE version (NE555) which has an operating temperature range between 0 and 70 C. The military hardened versions (SE) have an operating temperature of -55 to 125 C and the SE-555P is also radiation tolerant. Naturally, these hardened versions are more expensive that your standard NE version.

However even these hardened versions have an useful operating temperature change, so part of the design should ensure that the temperature is kept well within this range. The end goal is to make sure that the product works reliably under operating conditions. Whether this is done by adding parts that can handle wider temperature ranges or by providing more cooling or a mixture of both is left to the designers :).

Viv S
BRF Oldie
Posts: 5303
Joined: 03 Jan 2010 00:46

Re: Armoured Vehicles Discussion Thread

Postby Viv S » 26 Apr 2010 21:56

Mrinal wrote:ViVS:"How come?"

Please read what Rohitvats has posted. How many times does one have to discuss/repeat the same thing, after all.

That is why I said this entire overheating business was being overhyped. This overheating business happened to a new batch of tanks brought out for a dog and pony show for the brass, which used systems calibrated for 50-55 deg versus 60 deg, whereas CVRDE people calibrated the trial tanks for 60 deg.


I was just wondering why this it hadn't come up in the earlier successful hot weather trials. I see it was a fresh batch of tanks. You replied while I was still editing my post, but okay I get it, the problem was overhyped.

Rahul M
Forum Moderator
Posts: 17050
Joined: 17 Aug 2005 21:09
Location: Skies over BRFATA
Contact:

Re: Armoured Vehicles Discussion Thread

Postby Rahul M » 26 Apr 2010 22:28

bhavik wrote:
Rahul M wrote:hmm, merk-I's that served in that war are supposed to have been the first in service tanks with ERA.


I believe the drawbacks mentioned for ERA are still true even with new age ERA -
http://en.wikipedia.org/wiki/Reactive_a ... ive_armour
Also had seen this being described on a Discovery Channel Video.

that's why wikipedia is not the last word.

negi
BRF Oldie
Posts: 13112
Joined: 27 Jul 2006 17:51
Location: Ban se dar nahin lagta , chootiyon se lagta hai .

Re: Armoured Vehicles Discussion Thread

Postby negi » 26 Apr 2010 22:31

Austin wrote:Do they ever use HEAT or HESH rounds from tanks in indirect fire mode like they do with large caliber shell ( 155 mm etc ) to take out targets at long ranges than that possible via Direct Fire ?

I don't think so , there is a constraint in terms of elevation angle through which the main gun can be maneuvered within confines of the turret where it can be fed manually or by an auto loader.
As it is now that most of the modern MBTs have gone for smooth bore guns (Chally-2s too are moving to L55) using HESH is not an option.


rohitvats
BR Mainsite Crew
Posts: 7734
Joined: 08 Sep 2005 18:24
Location: Jatland

Re: Armoured Vehicles Discussion Thread

Postby rohitvats » 26 Apr 2010 23:40

Viv S wrote:<SNIP>

:-o Hadn't read that before. Must have missed it. Would you mind posting the entire link. Cheers! <SNIP>


Viv S, this is what I had posted:


rohitvats wrote:
Viv, as per the 11th Parliamentary Standing Committe on Defense Report - 14 Lok Sabha - 2006-07, the problem was as follows:

The Ministry in their subsequent note on latest position of the Arjun Tank further stated as under:

“Five production tanks (Nos 001 to 005) were subjected to comparative trials during June 2005 wherein some defects were reported by the User with regard to (a) fire control system and (b) gun control system. In view of these defects the tanks were withdrawn by DRDO to carry out extensive re-examinations, system defect analysis, carry out rectification work and re offer at a later date as and when these tanks are fully prepared for its readiness by conducting in – House (DRDO) revalidation trials to fully satisfy the user requirements. Accordingly, a plan of action was charted out to resolve all issues.

Broadly, the problems are comprising to OEM supplies only, viz. (a) OIP Sagem Belgium – France (for GMS/LRF), and (b) Rexrath, Germany (for Gun control system). Rest are all minor issues pertaining to quality and workmanship/assembly
integration which has already been resolved.

As regards current factual status of Arjun Tank the Ministry in their written note further stated as under:

“All tanks 001 to 005 at MFFR (IMO, this stands for Mahajan Field Firing Range) are updated with complete improvements duly in house validated in respect of (a) GCS (b)Automotive systems (c) FCS systems (except for the LRF meeting 60 C temp spec). Tank No. 002 to 005 are expected to be fitted with LRF meeting 60 temp Spec by 25th May, soon thereafter Army’s evaluation will start off.”


<SNIP>

The exact nature of the problem with GCS and LRF is further explained in the 14th Parliamentary Standing Committe on Defense Report - 14 Lok Sabha - 2006-07:

During oral evidence, on the production of MBT Arjun, the representative of the Ministry informed the Committee :—

<SNIP> (this section of reply has been ommitted by me)

Regarding the snag, he further stated :—

“Sir, we have driven them and for over 60,000 kms and fired more than 8,000 rounds. There was no problem. What happens is that in the gun control system, there are power amplifiers which are used in the fire control system. Some temperature settings were not properly done by the parent company. These were tucked inside. As you know, now-a-days, the deck is packaged so densely even to get access to that you have to take out the whole module. So, when this type of settings get disturbed, the rule says that one has to go through the whole qualification process again. There is no change in the design. It is a temperature re-setting which was got done. That has been rectified. Now the tanks would be there by the middle of January”.

During oral evidence, on the problems faced by MBT Arjun during trials, the representative of the Ministry apprised the
Committee :-

“In the Arjun, we got into a little bit of a problem because certain temperature-setting switches were not tuned properly. They had to be returned. Yes, this was a problem of the Defence Research Scientists who have not seen that 60 degree setting was not kept at 60, but at 55 which is a normal standard of that company which supplied those parts follow. But we had in the prototype modified that for the 60. so, this had to be done. Once this got done, now we are ready. So some of these productions hiccup if they do take place in the initial phase, they should not dispirit us because whenever we do new products like that, we may face these kinds of problems”.

Viv S
BRF Oldie
Posts: 5303
Joined: 03 Jan 2010 00:46

Re: Armoured Vehicles Discussion Thread

Postby Viv S » 27 Apr 2010 00:02

rohitvats wrote:
Viv S, this is what I had posted:


Thanks. Appreciate it.

chackojoseph
BRF Oldie
Posts: 4297
Joined: 01 Mar 2010 22:42
Location: From Frontier India
Contact:

Re: Armoured Vehicles Discussion Thread

Postby chackojoseph » 27 Apr 2010 08:01

Viv S wrote:
chackojoseph wrote:

Army top brass is the most miffed category in the Armed forces. And no, they did not sit in the hot sun. They were also drinking "cold" lassi and munching nuts. Then they laughed and flew away in their choppers.


Well it was still hot. How can you expect them to order the Arjun after putting them through such a harsh experience.


If so, we must ship the jenerails to Kuwait for air conditioned tents.

niran
BRF Oldie
Posts: 5426
Joined: 11 Apr 2007 16:01

Re: Armoured Vehicles Discussion Thread

Postby niran » 27 Apr 2010 09:46

chackojoseph wrote:
If so, we must ship the jenerails to Kuwait for air conditioned tents.

the correct way to go is
-issue a GSQR and make DRDO to design and produce
-in the interim order some imports minus the ac(to keep price low)
-order some ac units seperately
-smile and say "all izz wel" while getting their collective Thumbs cooked under non functioning ac.
- cook up silliest excuse to reject DRDO tents.

Sanku
BRF Oldie
Posts: 12526
Joined: 23 Aug 2007 15:57
Location: Naaahhhh

Re: Armoured Vehicles Discussion Thread

Postby Sanku » 27 Apr 2010 10:49

ArmenT wrote:
Sanku wrote:Ok for Arjun, AFAIK, its not the electronics that themselves are hardened, but it is the tank design itself which ensures sufficient cooling (airflow, large spaces, special cooling?) for the electronics.

Basically a simple analogy would be, if you put a high end graphics processor in a lap top it will die, however in a large roomy desktop with a fan etc, it works well.

This was what JCage said if I am not wrong. Any opinions?

Bit of both actually.

The military hardened versions (SE) have an operating temperature of -55 to 125 C and the SE-555P is also radiation tolerant.


Right, however in context of TIs on T 90 conking of sometimes as compared to the Arjun electronics less prone to the same, both the electronics would be in Military specification category (safe assumption) The French particularly are quite adept at Mil grade electronics.

http://www.thalesgroup.com/Portfolio/De ... /?pid=1568
• Spectral band: 8-12μm (LWIR – the proven
solution for the battlefield) or 3-5μm (MWIR)
• Cooled technology
• Full MIL Spec
• Compatible with AFV Fire Control applications

• Long range surveillance and target acquisition
• Day and Night + Adverse conditions
• Ability to see through barriers such as vegetation, camouflage netting…
• World leader outside US market for Thermal Imager for AFV
• The most complete range of Thermal Imagers


The difference primarily comes from the roomier space on Arjun's roomier space in this particular context I think.

Sanku
BRF Oldie
Posts: 12526
Joined: 23 Aug 2007 15:57
Location: Naaahhhh

Re: Armoured Vehicles Discussion Thread

Postby Sanku » 27 Apr 2010 10:54

negi wrote:
Austin wrote:Do they ever use HEAT or HESH rounds from tanks in indirect fire mode like they do with large caliber shell ( 155 mm etc ) to take out targets at long ranges than that possible via Direct Fire ?

I don't think so , there is a constraint in terms of elevation angle through which the main gun can be maneuvered within confines of the turret where it can be fed manually or by an auto loader.
As it is now that most of the modern MBTs have gone for smooth bore guns (Chally-2s too are moving to L55) using HESH is not an option.


This is one of the issues I suppose should be corrected in Arjun Mk II. The reason why Arjun was asked to have a rifled gun was the IA experience around Vijayanta's etc. in 1960s-70s.

With Arjun turning up 20 years after it was supposed to come online (mass production was by end of 80s) that requirement simply does not make sense any more.

I SUSPECT that the T 90 ToT especially for tank barrels was a important item because Arjun Mk II is going to go with smooth bore guns basically piggy backing on Russian tech for T 90 guns.

Karan M
Forum Moderator
Posts: 19839
Joined: 19 Mar 2010 00:58

Re: Armoured Vehicles Discussion Thread

Postby Karan M » 27 Apr 2010 11:17

As far as I know, there has been no requirement for a smoothbore gun. Depending on Russia would be particularly ironic given Russia reneged on TOT for the barrels which was solved only after some heavy negotiation (arm twisting). Further improvements on the 120mm are more likely based on inhouse experience.

Also, the Arjun has not turned up 20 years after it was supposed to in terms of specifications. The Arjun GSQR was set in 1984-85, aiming for a futuristic tank to be capable of operations in the 2000 plus timeframe. Some more things were added later according to CVRDE in 2008, so it has been constantly improved. It bears remarking that the features on the Arjun are superior to those on the T-90 today, and some are probably matched by improvements in the next T-90. But the Arjun will also improve in turn.

Ajai Shukla has mentioned 7 additions to the Arjun MK2 apart from the ERA and Commanders sight, but these will be iterative, and it is unlikely CVRDE will take some radical measures to change the tank design.

Sanku
BRF Oldie
Posts: 12526
Joined: 23 Aug 2007 15:57
Location: Naaahhhh

Re: Armoured Vehicles Discussion Thread

Postby Sanku » 27 Apr 2010 11:33

Mrinal wrote:As far as I know, there has been no requirement for a smoothbore gun. Depending on Russia would be particularly ironic given Russia reneged on TOT for the barrels which was solved only after some heavy negotiation (arm twisting). Further improvements on the 120mm are more likely based on inhouse experience.


Mrinal aren't you missing some basic stuff here.

The T 90 ToT HAS happened. IT HAS BEEN absorbed. Home made T 90s are rolling out NOW.

I am saying that past experience will be leveraged for future smooth bore guns.

What "dependence" on Russia are we talking of here? I am talking of past ToT.

Also Russia never reneged on ToT, ToT was held up till the contract was FULLY sorted out using IP protection clauses. BIG DIFFERENCE.

Also, the Arjun has not turned up 20 years after it was supposed to in terms of specifications. The Arjun GSQR was set in 1984-85, aiming for a futuristic tank to be capable of operations in the 2000 plus timeframe. \


Please Mrinal we have been over this 1001 times. The Arjun GSQR was redone in 85 because in 75 GSQRs and plan calling for induction by 80s were not met.

Spare me the history discussion, I am bored of revisiting it time and again.

Ajai Shukla has mentioned 7 additions to the Arjun MK2 apart from the ERA and Commanders sight, but these will be iterative, and it is unlikely CVRDE will take some radical measures to change the tank design.


How is a change in gun "radical"?

Given that the world is moving towards commonality, what sense does it make to keep rifled gun for pretty much the only tank in the world?

Austin
BRF Oldie
Posts: 23387
Joined: 23 Jul 2000 11:31

Re: Armoured Vehicles Discussion Thread

Postby Austin » 27 Apr 2010 11:39

So do Rifled Gun need a different ammo versus smooth bore 120mm Gun , say for eg most of the western MBT are smooth bore 120 mm , can we use Sabbot/HEAT 120 mm round from US ,Israel and fire it from Rifled Arjun gun without modification to ammo ?

chackojoseph
BRF Oldie
Posts: 4297
Joined: 01 Mar 2010 22:42
Location: From Frontier India
Contact:

Re: Armoured Vehicles Discussion Thread

Postby chackojoseph » 27 Apr 2010 11:43

Arjun gun required to fire all 3 types of ammo, hence the rifled.

Once speaking to to CVRDE, I mentioned the smoothbore gun. I was told, it doesn't matter, we can make what gun we want. We have the required expertise.

Non-CVRDE realted.

With T-90 (logically the Russian equipment), Russians use their "own standard" or "non standard" or would not divulge "which standard" they use for their equipment. Hence its difficult to copy their stuff to needed specs. So, they wanted to get hold of the Russian tech which was promised and budgeted.

===============

Just corrected some mistakes.
Last edited by chackojoseph on 27 Apr 2010 12:55, edited 1 time in total.

Boudhayan
BRFite -Trainee
Posts: 37
Joined: 10 Feb 2010 10:16

Re: Armoured Vehicles Discussion Thread

Postby Boudhayan » 27 Apr 2010 11:53

Sorry to distract everyone from the technical discussion but do we have any chaiwalla/paanwalla or official news about new orders for Arjun as well as the official result from MoD for the trials against T90 ? We do know that the T90 was "out-gunned and out-ran" by the Arjun but no official confirmation from the MoD yet :cry:

Surya
BRF Oldie
Posts: 5034
Joined: 05 Mar 2001 12:31

Re: Armoured Vehicles Discussion Thread

Postby Surya » 27 Apr 2010 11:59

I SUSPECT that the T 90 ToT especially for tank barrels was a important item because Arjun Mk II is going to go with smooth bore guns basically piggy backing on Russian tech for T 90 guns.


all speculation.

If Army wants smoothbore now AND if we need help there are better alternatives out there to go for assistance than the Russian stuff.

chackojoseph
BRF Oldie
Posts: 4297
Joined: 01 Mar 2010 22:42
Location: From Frontier India
Contact:

Re: Armoured Vehicles Discussion Thread

Postby chackojoseph » 27 Apr 2010 12:12

Boudhayan wrote:Sorry to distract everyone from the technical discussion but do we have any chaiwalla/paanwalla or official news about new orders for Arjun as well as the official result from MoD for the trials against T90 ? We do know that the T90 was "out-gunned and out-ran" by the Arjun but no official confirmation from the MoD yet :cry:


As per Antony's statement in parliament, the evaluation is still going on and the numbers will be based on that. Also the new General has principally agreed to buy more of Arjuns (and Akash).

Its a matter of time. Army needs time to figure out deployments and will take time. The alleged Arjun performance was unexpected development. We need to give them time to figure out next move.

Sanku
BRF Oldie
Posts: 12526
Joined: 23 Aug 2007 15:57
Location: Naaahhhh

Re: Armoured Vehicles Discussion Thread

Postby Sanku » 27 Apr 2010 12:22

Surya wrote:
I SUSPECT that the T 90 ToT especially for tank barrels was a important item because Arjun Mk II is going to go with smooth bore guns basically piggy backing on Russian tech for T 90 guns.


all speculation.

If Army wants smoothbore now AND if we need help there are better alternatives out there to go for assistance than the Russian stuff.


Two things

1) I wrote I SUSPECT in capital. So CLEARLY speculation, about Mk II.
2) The Russian assistance HAS already happened. As Chacko said, CVRDE needed the understanding of Russian systems which they got via ToT.
:mrgreen:

What I am saying is that CVRDE may be tasked with a smooth bore gun now for Mk II. I also think that IA+CVRDE were aware that this would come up, and this was one of the major requirements for understanding Russian systems in depth.

So they could attempt commonlity between ammunition.

vina
BRF Oldie
Posts: 6046
Joined: 11 May 2005 06:56
Location: Doing Nijikaran, Udharikaran and Baazarikaran to Commies and Assorted Leftists

Re: Armoured Vehicles Discussion Thread

Postby vina » 27 Apr 2010 12:25

Mrinal aren't you missing some basic stuff here.

The T 90 ToT HAS happened. IT HAS BEEN absorbed. Home made T 90s are rolling out NOW.


So were T-72s that were rolling out for nearly 2 decades. What "technology" was absorbed from the T 72s, that you suddenly managed to do with the T90

I am saying that past experience will be leveraged for future smooth bore guns.


Why do you need a smooth bore gun ?. They did exactly that with the rifled gun for the Arjun. Used "past" experience with the Royal Ordnance L-105 mm rifled main gun (widely considered one of the best tank guns ever made) and made a 120mm rifled gun . There is no great shakes in making a smooth bore gun if we wanted to. Heck all you need to do is remove the rifling in the existing gun and bore it smooth. In fact, easier to make I suppose than the rifled gun.

Also Russia never reneged on ToT, ToT was held up till the contract was FULLY sorted out using IP protection clauses. BIG DIFFERENCE


Err. Heard of the Cryogenic engine ?. What if the "IP Protection" clause actually is about putting in conditions that makes sure that you cant use equipment and design and whatever to make "derivative" / "new products" / reuse components in any other product ?. That is usually what those closes specify!.

vina
BRF Oldie
Posts: 6046
Joined: 11 May 2005 06:56
Location: Doing Nijikaran, Udharikaran and Baazarikaran to Commies and Assorted Leftists

Re: Armoured Vehicles Discussion Thread

Postby vina » 27 Apr 2010 12:37

Sanku wrote:Given that the world is moving towards commonality, what sense does it make to keep rifled gun for pretty much the only tank in the world?


What do you mean by "commonality" . It is like saying just because the AK-47 and the Insas and M-16 are ALL assault rifles, each should be able to fire the other's ammo! .

Likewise, the Russian standard is a 125mm bore, the western standard (the rest of the world , Nato, Unkil, Isreal, Korea, France, etc) practically standardized on the Rheinmetall 120mm gun. Now the only "outlier" was UK, because they had a design of their own.

If you want to be able to fire Nato/Unkil/Isreali ammo, you need the Rheinmetall like 120mm..And that is a make vs buy decision. Rheinmentall will be happy to give you full license (just like they did to Unkil, Isreal, So Ko , France etc) and you can make it here in India. Or if you want, we can make our own 120mm smoothbore, which given the availability off the shelf, makes little sense.

Dont get confused between the 125mm Russian standard and the Rest of the World /Nato 120mm standard. Nato standard gives wider choice. The Russian standard means, Russian,PRC and former eastern bloc countries (who anyways will junk the Russian systems and go to Nato Standards over due course).

Sanku
BRF Oldie
Posts: 12526
Joined: 23 Aug 2007 15:57
Location: Naaahhhh

Re: Armoured Vehicles Discussion Thread

Postby Sanku » 27 Apr 2010 12:54

vina wrote:So were T-72s that were rolling out for nearly 2 decades. What "technology" was absorbed from the T 72s, that you suddenly managed to do with the T90


Hmm, clearly Avadi+CVRDE was unable to manufacture tank barrels (and in general the sterling record of Indian Mil-Ind complex at manufacturing guns) with ToT.

So you ask them directly, may be they will tell you?
:twisted:

My understanding is probably metallurgy. Better gun performances.

There is no great shakes in making a smooth bore gun if we wanted to. Heck all you need to do is remove the rifling in the existing gun and bore it smooth.


Fine so you say. Perhaps there is more? Perhaps the tolerances have to be smaller? Perhaps the stress on metal and barrel heating is more since wearing out of rifling is not an option?

In short yes, its theoretically easy? But have we actually made it to the needed standards (of life weight etc?)

Err. Heard of the Cryogenic engine ?.


Amma that was a response to T 90 discussion saar. Where did Cryo come in? Why take the statement out of context?

What if the "IP Protection" clause actually is about putting in conditions that makes sure that you cant use equipment and design and whatever to make "derivative" / "new products" / reuse components in any other product ?. That is usually what those closes specify!.


Yes Sir, and that is why I am saying that they needed the smooth bore gun tech and Russians were chary of giving it to us.
:mrgreen:


Return to “Mil-Tech Archive”

Who is online

Users browsing this forum: No registered users and 2 guests