Artillery: News & Discussion

Sagar G
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Re: Artillery Discussion Thread

Postby Sagar G » 18 Oct 2013 21:16

negi wrote:my question was does OFB screen out candidates based on GATE ? If it is their internal selection process it is going to be a case of a bad apple selecting another .


I have already answered this.

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Re: Artillery Discussion Thread

Postby Victor » 18 Oct 2013 21:18

Karan M wrote:Shri Antony has presided over the (dis)armament of the Indian services..

Hence the question: to what end? I truly doubt that keeping his lungi unsullied is the answer.

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Re: Artillery Discussion Thread

Postby agupta » 18 Oct 2013 21:26

Karan_M's synopsis sounds about right from what I recall in those days in the DRDO circles...

They got caught screwing up. The Hyd orgs helped figure out the root cause. They claimed it was not a screw-up, but a deliberate decision that was sanctioned by the Russkies. Then the Russkies denied it - washed their hands off . Then they said they had limitations.

The problem in this scenario is not money , or cost of facilities. Its the repeated lying and lack of accountability and competence. ... its like Homer Simpson... "I didnt do it - nobody saw it - you cant prove anything". I know several good people from Hyd who went on to do lots of impactful stuff who went to the OFBs on deputation and came back shaking their heads in disbelief at the levels of that AND corruption in the OFBs - and these are not shrinking violets but wizened folks very used to standard MoD/DPSU "levels" of chalta hai.

More recently you had the OFB head who was claiming he'll have import content down from some large number (80%?) to a low number (30%?) in 3 months for the Howitzer when the base version hasn't even passed all of its minimum reliability and performance trails. Cart before horse ! Reminded me of the HAL chief (or was it GTRE) Narayanan, who promised in 2006 that the Kaveri would be flying on the LCA in what, 6 or 9 months ! Anybody who is so wrong at such a short time-scale of a complex system is either incompetent or lying... and everyone even in upper-mid management in GTRE/DRDO/ADA/HAL knew that was not going to happen when that statement was made.

All of these guys belong to VSA school of shabda-yogis... thank god DRDO has had a bunch of karma-yogis (Kalam, Agarwal, Chander) who've put their lives towards repairing the damage caused by him and his kind... its fantastic to hear Chander talk about ensuring reliable bread n butter products like Guns and Ammo for the Armed Forces - really tells you his heart is in serving the soldier and country, not in getting glamor, fame and political currency in N Delhi !

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Re: Artillery Discussion Thread

Postby Karan M » 18 Oct 2013 21:33

Sagar G wrote:
Karan M wrote:Actually CAG mentions that DGQA rejected the barrels but OFB claimed that it had permission from the Russians to do the tempering at a lower temperature. Subsequently, the Russians noted that the original designer/manufacturer had not been consulted and hence the OFB method was wrong. OFB claims it did it because it did not have the machinery to temper at higher termperatures.


CAG say's

The responsibility for quality assurance of items manufactured in Ordnance factories rests with the manufacturing factory. Director General Quality Assurance and Inspectorates under him are responsible for surveillance, quality audit and final acceptance inspection. In surveillance check of barrels during manufacture in Field Gun Factory, Kanpur in 1990, when one of the barrels broke in the straightening operation, the Quality Assurance Establishment (Field Gun), notified the Factory that to avoid such breakage, the heat treatment should be carried out at 520�C-570�C as provided by designer. The Field Gun Factory Kanpur however, continued tempering the forgings at reduced temperature even below 430�C, on the plea that the protocol signed by it with Russian team in 1985, permitted the heat treatment at lower range.


Either OF is lying about this "Russian team" or they have what they claim and since I don't see the CAG saying that they don't have that signed protocol then we can they that they had the same. So if it wasn't the original designer then who the hell were these Russians ??? DGQA must have asked for the same document as well since they had also asked OF to follow the original specification and I don't think that a mere verbal assurance from OF might have sufficed them regarding heat treatment at low temperature.


Exactly. That is what is also indicated in the article by RSundaram - combining what RS and CAG say, OFB took a very risky (and IMHO incorrect) way out by asking for relaxed specs to match whatever they had in terms of machinery (OFB is usually rushing to get things into production to meet quota, QA be darned) and got "some Russians" to sign off on it. They then used this as a counter to get DGQA guys to agree to it. Apparently though, the Russian guys whom OFB cites were not the right folks (and did not include the actual designers/manufacturers of the gun barrels) and the whole mess escalated. Or the protocol was hazy on tempering temperatures (which I doubt since otherwise how would DGQA have the data) and OFB played it fast and loose. Eitherways, this is one more of a long series of OFB mess ups in QA in their rush to meet production schedules exacerbated by the Russian's and their reluctance to assist unless pushed (per RSundaram).

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Re: Artillery Discussion Thread

Postby Sagar G » 18 Oct 2013 21:54

Karan M wrote:Exactly. That is what is also indicated in the article by RSundaram - combining what RS and CAG say, OFB took a very risky (and IMHO incorrect) way out by asking for relaxed specs to match whatever they had in terms of machinery (OFB is usually rushing to get things into production to meet quota, QA be darned) and got "some Russians" to sign off on it. They then used this as a counter to get DGQA guys to agree to it. Apparently though, the Russian guys whom OFB cites were not the right folks (and did not include the actual designers/manufacturers of the gun barrels) and the whole mess escalated. Or the protocol was hazy on tempering temperatures (which I doubt since otherwise how would DGQA have the data) and OFB played it fast and loose. Eitherways, this is one more of a long series of OFB mess ups in QA in their rush to meet production schedules exacerbated by the Russian's and their reluctance to assist unless pushed (per RSundaram).


Note that the CAG report is from 1999 and from the report itself

Army Headquarters decided in December 1997 to withdraw all barrels tempered at 460�C and below. As of June 1998, 454 such barrels valued at Rs 44 crore from stock were identified and rejected and remaining 305 barrels fitted on tanks were under investigation. Tempering of barrels were now being done at temperatures above 500�C.


So everything is as per spec. now and there must not be any problem no right ??? But see what Kanson has posted

MINISTRY OF DEFENCE DEPARTMENT OF DEFENCE PRODUCTION AND SUPPLIES
RAJYA SABHA UNSTARRED QUESTION NO 900
TO BE ANSWERED ON 02.08.2006
DEFECTIVE BARRELS USED IN T TANKS

(c) During the last three years, 26 cases of barrel burst (14 with imported barrels and 12 with indigenous barrels) have occurred.


So the time frame now is from 03 to 06 and yet the problem persists and don't forget that the tempering is now being done as per the "original designer" specification as noted by CAG itself. Also note what R. Sundaram says,

Another important aspect highlighted by the retired General was the incident of bursting of gun barrels of T-72 tanks. Although these have been produced in the erstwhile USSR and East European countries since early eighties in huge quantities, the problem dogged this product for long. In India, too, this occurred in barrels of both foreign and indigenous origins. Getting inputs from Russia to make improvements as implemented over there took more than half a dozen delegation-level meetings between the two countries. Although after valiant efforts some details of heat-treatment processes were obtained and implemented, there is no knowing that the problem has, indeed, been licked, since Russia does not share ‘know why’.


So it's not that OFB acted independently went ahead signed documents with Russians waltzing on their streets and claimed to have protocols signed by them. Even after the heat treatment process has been implemented the problem has persisted so it would be false to think that CAG/Russkies nailed the problem and everyone lived happily ever after.

Arjun tank barrel is also produced by us but that doesn't burst (touch wood), so what supaah dupaah tech is in the tin can barrel that even after implementing their recommendation the barrels still burst ???

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Re: Artillery Discussion Thread

Postby ramana » 18 Oct 2013 22:01

If the barrel broke during straightening operation then it was too hard and not tampered right.

Steel has to be hardened by heating to the Rc temperature for that alloy and then quenched.
It then has to be tempered by heating to a particular temperature(500 deg C per above CAG report) for that alloy it varies for a particular time(to enable complete soak and not just the skin) to enable transformation to pearlite + cementite or ferrite based on its eutecticness (hyper or hypo). So by heating to a lower temperature(460 deg C) some of the hardened crystals are still present and could cause the defect upon pressurization during.


Google books:

Steel Metallurgy for the Non Metallurgist from American Society of Metals (ASM)

iron-iron Carbide Diagram:

http://www.sv.vt.edu/classes/MSE2094_No ... imcon.html


I could draw this from memory on a paper napkin in the shops in my early days.

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Re: Artillery Discussion Thread

Postby Sagar G » 18 Oct 2013 22:13

^^^ Even after implementing the heat treatment process as specified the barrels (both indigenous and imported) have bursted what do you make of that ????

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Re: Artillery Discussion Thread

Postby Karan M » 18 Oct 2013 22:23

Sagar G wrote:
Karan M wrote:Exactly. That is what is also indicated in the article by RSundaram - combining what RS and CAG say, OFB took a very risky (and IMHO incorrect) way out by asking for relaxed specs to match whatever they had in terms of machinery (OFB is usually rushing to get things into production to meet quota, QA be darned) and got "some Russians" to sign off on it. They then used this as a counter to get DGQA guys to agree to it. Apparently though, the Russian guys whom OFB cites were not the right folks (and did not include the actual designers/manufacturers of the gun barrels) and the whole mess escalated. Or the protocol was hazy on tempering temperatures (which I doubt since otherwise how would DGQA have the data) and OFB played it fast and loose. Eitherways, this is one more of a long series of OFB mess ups in QA in their rush to meet production schedules exacerbated by the Russian's and their reluctance to assist unless pushed (per RSundaram).


Note that the CAG report is from 1999 and from the report itself

Army Headquarters decided in December 1997 to withdraw all barrels tempered at 460�C and below. As of June 1998, 454 such barrels valued at Rs 44 crore from stock were identified and rejected and remaining 305 barrels fitted on tanks were under investigation. Tempering of barrels were now being done at temperatures above 500�C.


So everything is as per spec. now and there must not be any problem no right ??? But see what Kanson has posted

MINISTRY OF DEFENCE DEPARTMENT OF DEFENCE PRODUCTION AND SUPPLIES
RAJYA SABHA UNSTARRED QUESTION NO 900
TO BE ANSWERED ON 02.08.2006
DEFECTIVE BARRELS USED IN T TANKS

(c) During the last three years, 26 cases of barrel burst (14 with imported barrels and 12 with indigenous barrels) have occurred.


So the time frame now is from 03 to 06 and yet the problem persists and don't forget that the tempering is now being done as per the "original designer" specification as noted by CAG itself. Also note what R. Sundaram says,

Another important aspect highlighted by the retired General was the incident of bursting of gun barrels of T-72 tanks. Although these have been produced in the erstwhile USSR and East European countries since early eighties in huge quantities, the problem dogged this product for long. In India, too, this occurred in barrels of both foreign and indigenous origins. Getting inputs from Russia to make improvements as implemented over there took more than half a dozen delegation-level meetings between the two countries. Although after valiant efforts some details of heat-treatment processes were obtained and implemented, there is no knowing that the problem has, indeed, been licked, since Russia does not share ‘know why’.


So it's not that OFB acted independently went ahead signed documents with Russians waltzing on their streets and claimed to have protocols signed by them. Even after the heat treatment process has been implemented the problem has persisted so it would be false to think that CAG/Russkies nailed the problem and everyone lived happily ever after.

Arjun tank barrel is also produced by us but that doesn't burst (touch wood), so what supaah dupaah tech is in the tin can barrel that even after implementing their recommendation the barrels still burst ???


Good points.

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Re: Artillery Discussion Thread

Postby Karan M » 18 Oct 2013 22:26

ramana wrote:If the barrel broke during straightening operation then it was too hard and not tampered right.

Steel has to be hardened by heating to the Rc temperature for that alloy and then quenched.
It then has to be tempered by heating to a particular temperature(500 deg C per above CAG report) for that alloy it varies for a particular time(to enable complete soak and not just the skin) to enable transformation to pearlite + cementite or ferrite based on its eutecticness (hyper or hypo). So by heating to a lower temperature(460 deg C) some of the hardened crystals are still present and could cause the defect upon pressurization during.


Google books:

Steel Metallurgy for the Non Metallurgist from American Society of Metals (ASM)

iron-iron Carbide Diagram:

http://www.sv.vt.edu/classes/MSE2094_No ... imcon.html


I could draw this from memory on anapkin in the shops in my early days.


Thanks for the details.

Judging by the points made by SagarG - the problem does persist.

I wonder whether it is also an ammunition compatability issue. Need to dig up the chamber pressures for the respective ammo's, fielded by India.

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Re: Artillery Discussion Thread

Postby Sagar G » 18 Oct 2013 22:28

All credit to Kanson he did the data mining.

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Re: Artillery Discussion Thread

Postby chackojoseph » 18 Oct 2013 22:33

^^^^^ + 1.

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Re: Artillery Discussion Thread

Postby Karan M » 18 Oct 2013 22:33

Now the big question is why was Project Maple dropped and why are we running back to Russia for new gun barrels. One step forward (attempt towards fault rectification), three steps back.

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Re: Artillery Discussion Thread

Postby Sagar G » 18 Oct 2013 22:38

Really Karan you don't know the answer to that :wink:

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Re: Artillery Discussion Thread

Postby Karan M » 18 Oct 2013 22:45

I would hesitate to ascribe everything to the usual .."could be corruption" angle - could simply be that the barrel explosions continued with Maple.
By 2006, last time it was reported, two Maple barrels were already sent to Israel for propellant development and 2 more were planned to be made by year end.
Also, a T-90 barrel was to be made, to be combined with the imported/Russian breech.. no reports on what happened to that program either.

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Re: Artillery Discussion Thread

Postby member_27862 » 18 Oct 2013 22:53

Karan M wrote:
sameerjoshi wrote:Gents, while all the smoke on our 125mm smooth bore ammo import is settling down, do we have any other option beside the BM42 FSAPDS AT round which as per you all is the mainstay of our Armoured formations now. Yes ARDE has something of a Mk2 version of the same, which I suspect is the desi version of the BM42M penetrator developed by the Ruskies sometime in mid 90s. But is there no better option for us ?


The BM42 APFSDS is the only one available from a non sanctioned supplier. Both IMI and Rheinmetall have been blacklisted by the MOD.
The MK2 round is not based on the BM42M (where would we ever get that from?) but an improved version of the earlier MK2, which was originally designed to match the IMI CL3254M which was introduced by OFB around 2005.

I recall reading sometime back that majority of Iraqi BM42 rounds fired by Iraqi T72s in the first gulf war, failed to even dent the Abrams frontal Chobham armour. Yes the Tungsten penetrator was blamed and the BM42M may have a better penetrator, but seriously guys, with the 125mm gun going to be the mainstay of our armoured formations in the T90 and the T72S, we need a better round than that


The Iraqis did not have the BM42. Lets be clear here - the BM42 is not a bad round, its just that its been superceded by newer rounds since the Russians effectively plateaued in their ammo development through the 90's-early 2000s due to economic troubles. Their newer rounds remain in trials and have not gone into series production.

The Iraqis had the much earlier 3BM-17/18 rounds.
http://fofanov.armor.kiev.ua/Tanks/ARM/apfsds/ammo.html

.....we need to bugger the Ruskies for a better round if we can't make one.... And please let's forget the Israelis and their economically attractive packages......or if nothing works lets call the boys from Ludhiana, they can even reverse engineer the moon :)


First, the 125mm round is in advanced stage of development. Please look at this:
viewtopic.php?p=1518429#p1518429

FSAPDS ammunition is the most lethal kinetic energy ammunition, capable of destroying all known tank armour up to direct shooting range. The 125 mm FSAPDS (soft core) ammunition has been successfully designed and developed for enhancing the fire power of existing T-72 tank. For T series tanks FSAPDS. DRDO has developed a soft core FSAPDS Mk I for For T72 Russian tanks. Technical trials for Mark II have been done and user trials are on. Production should begin by 2015. After 2015 we will be able to reduce import dependency. For Arjun FSAPDS is totally developed by ARDE.


Second, you are severely underestimating how complex FSAPDS design and development, and finally manufacture is. It requires the most complex design ability, plus advances in metallurgy, composite materials and finally, production is another kettle of fish altogether. HAPP was set up at Trichy by DRDO to manufacture the KE projectile assemblies and even that went through a lot of challenges in getting the tech ready. Then there are challenges in propellants, casings etc and even the sabot. Net - getting FSAPDS production up and running is a non trivial task, and in fact India is one of the few countries even attempting such an effort on its own and with its own FSAPDS program, as versus merely license producing


OK point taken and I stand corrected on the BM42 mixup by the Iraqis in the Gulf war....and no I do not underestimate the complexities of a FSAPDS.....but I am unable to fathom why did we not pester the Ruskies for the composite sabot BM46 (or the likes of the newer gen rounds) and decided in for the supply of the older BM42 from Russia.......Yes the DRDO is busy developing a new penetrator for the 125mm smooth bore (and has one in place for the Arjun 120mm Rifled gun -although I feel what we need in the next Arjun variant is a longer and better FSAPDS round on the lines of German DM-53), but is it worth having a 'not so superior' round as a stopgap till the time the production starts at DRDO to fill the void...beats me!

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Re: Artillery Discussion Thread

Postby ramana » 18 Oct 2013 22:58

Sagar G wrote:^^^ Even after implementing the heat treatment process as specified the barrels (both indigenous and imported) have bursted what do you make of that ????



Propellent over charge?

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Re: Artillery Discussion Thread

Postby Sagar G » 18 Oct 2013 23:04

Karan M wrote:I would hesitate to ascribe everything to the usual .."could be corruption" angle - could simply be that the barrel explosions continued with Maple.
By 2006, last time it was reported, two Maple barrels were already sent to Israel for propellant development and 2 more were planned to be made by year end.


Haah sounds so familiar, just like that indigenization programs cease to exist.

Karan M wrote:Also, a T-90 barrel was to be made, to be combined with the imported/Russian breech.. no reports on what happened to that program either.


Shook law reported back in 28th Nov 11

Then HVF officials discovered that Russia had withheld key T-90S technologies without valid reason. This included technology for crucial components like the tank’s main gun and a key section of the turret armour. When New Delhi demanded those technologies, Moscow blandly responded that they were secret. To this day, Russia has not transferred full technology for building the T-90S in India.

The MoD has not responded to emailed questions about this issue. But when Business Standard asked MSN Rao, General Manager of HVF Avadi, how the T-90S was being built without these technologies, he confirmed: “We developed the tank gun indigenously in Central Ordnance Depot, Kanpur, and the turret armour component in CVRDE (Combat Vehicles R&D Establishment), Avadi. This is still a sticking point between India and Russia.”

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Re: Artillery Discussion Thread

Postby Sagar G » 18 Oct 2013 23:11

ramana wrote:
Sagar G wrote:^^^ Even after implementing the heat treatment process as specified the barrels (both indigenous and imported) have bursted what do you make of that ????



Propellent over charge?


No saar, two points supporting my argument first the CAG doesn't mention it and second again quoting from Kanson's link

(d) Cases of premature failure/barrel burst have been thoroughly investigated, and the opinion of Russian experts was also sought by Ministry of Defence. The suggested improvements in manufacturing process have been implemented. Some barrels, which were suspected to be defective were segregated and utilized for proof of ammunition only.


The barrels were still bursting due to poor technical input from Russians who were either doing it on purpose or had no clue about it.

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Re: Artillery Discussion Thread

Postby Sagar G » 18 Oct 2013 23:19

Now to remind ourselves of the current "fix"

India to replace bursting T-72 tank barrels under Rs 1,500 cr deal with Russia

NEW DELHI: Seeking to address the issue of bursting barrels of Army tanks due to ammunition, the government is planning to replace them with canons of T-90 tanks in collaboration with Russia.

T-72 tanks, the mainstay of the Indian armoured fleet, are facing problems with their ammunition as they sometimes burst in the barrel and 200 such cases have been reported causing concern in the Army.

The Defence Ministry is planning to replace the barrels of the T-72 tanks with the ones fitted in the T-90 tanks. Under the plan, around 800 barrels are to be procured from Russia under a deal expected to be worth around Rs 1,500 crore, government sources told PTI here.

The issue is expected to be taken up for discussion during the high-level talks between India and Russia during the visit of Defence Secretary Radha Kant Mathur to Moscow next week, they said.

Earlier this year, the Army told a Parliamentary panel that barrels burst sometimes due to ammunition and wondered whether its troops will be "afraid" to fire even after seeing the enemy.

"It (the T-72 ammunition) used to burst in the barrel. If it bursts in the barrel, then the firer is afraid to fire his own gun, which is not a correct thing. If he is afraid to fire his own gun, then even if he sees the enemy he will not fire," the Army had told the Standing Committee on Defence.

The Army informed the government and the Parliamentary Committee that over a period of time, there have been 200 such accidents involving the ammunition and "it brings down the confidence of the firer, especially, with regard to tank ammunition".

In terms of the numbers, the T-72 tanks are the backbone of the Indian armoured fleet and have undergone several upgrades since their induction to be able to fight effectively in the battlefield.


Huh what ??? So the T-90 barrel is strong enough to withstand an ammunition burst within it !!!!! Can anybody confirm this ???

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Re: Artillery Discussion Thread

Postby negi » 18 Oct 2013 23:43

We deserve all these barrel bursts, Ru and others have basically posed a question to us that we are like this onlee , what are you going to do about it ?
No one parts with IP at a level of detail which we expect people to share with us; hell we ourselves do not like to spoonfeed kids/colleagues or anyone for that matter .
The idea is to enable the seeker of knowledge to do research the fruits are something which no one promises , this is not Treta yuga where one will extend his hand , close eyes and whisper a mantra or two and Brahmastra will get materialized from thin air.

As for the ammo woes one never knows if it was a case of the shell being stored under GOI issued tarpaulin mats in a open field exposed to elements for years and then ending up at the site of testing , such shells either don't go off or go off in barrels.

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Re: Artillery Discussion Thread

Postby rohitvats » 19 Oct 2013 00:02

Sagar G wrote: Either OF is lying about this "Russian team" or they have what they claim and since I don't see the CAG saying that they don't have that signed protocol then we can they that they had the same. So if it wasn't the original designer then who the hell were these Russians ??? DGQA must have asked for the same document as well since they had also asked OF to follow the original specification and I don't think that a mere verbal assurance from OF might have sufficed them regarding heat treatment at low temperature.


I would request you to please read this part of the same CAG Report as well:

DDPS placed order on MIDHANI for supply of 774 barrels

Department of Defence Production and Supplies placed an order on Mishra Dhatu Nigam Limited., Hyderabad in October 1989 for supply of 774 barrels to be fitted in T-72 tanks, at a cost of Rs 67.73 crore.

Mishra Dhatu Nigam Limited, in turn, placed a letter of intent in March 1990 on Director General Ordnance Factories for converting black forging hot rolled bars i.e. input raw materials into finished, machined and tested barrels. The letter of intent envisaged that the tempering of barrels would be carried out in two stages viz. in first stage in the temperature range of 520-550°C and in the second stage in the temperature range of 530-570°C. The barrels were to be supplied by the Director General Ordnance Factories to Central Ordnance Depot Jabalpur only after testing by Controllerate of Quality Assurance (weapons) Jabalpur.<SNIP>


Now, what would be the answer to these questions:

- MDNL LOI to OFB specifically mentioned the temperature at different stages of process for the barrel - So, on what authority did OFB deviate from the process?

- If MDNL knew about the temperature requirement and specifically mentioned the same, on what basis is the claim being made that the process for manufacturing barrels was obtained only after rounds of consultations with Russians?

- If the barrel was found to be faulty on inspection of manufacturing process by QA team, why did OFB continue with the same process? And this when the BUYER had mentioned a particular temperature range?

As I said earlier, the author of Hindu article was being economical with facts.

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Re: Artillery Discussion Thread

Postby rohitvats » 19 Oct 2013 00:07

Karan M wrote:<SNIP>

Exactly. That is what is also indicated in the article by RSundaram - combining what RS and CAG say, OFB took a very risky (and IMHO incorrect) way out by asking for relaxed specs to match whatever they had in terms of machinery (OFB is usually rushing to get things into production to meet quota, QA be darned) and got "some Russians" to sign off on it. They then used this as a counter to get DGQA guys to agree to it. Apparently though, the Russian guys whom OFB cites were not the right folks (and did not include the actual designers/manufacturers of the gun barrels) and the whole mess escalated. Or the protocol was hazy on tempering temperatures (which I doubt since otherwise how would DGQA have the data) and OFB played it fast and loose. Eitherways, this is one more of a long series of OFB mess ups in QA in their rush to meet production schedules exacerbated by the Russian's and their reluctance to assist unless pushed (per RSundaram).


Well, the funny thing in this case is that the BUYER - Mishra Dhatu Nigam Limited - asked in Letter of Intent (LOI) to use 500+ degree temperature for the barrels.

Here is the excerpt from the same 2001 CAG report:

The letter of intent envisaged that the tempering of barrels would be carried out in two stages viz. in first stage in the temperature range of 520-550°C and in the second stage in the temperature range of 530-570°C


So, on what authority did OFB not follow BUYERS instructions? And why are Russians being blamed?

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Re: Artillery Discussion Thread

Postby Karan M » 19 Oct 2013 00:14

sameerjoshi wrote:OK point taken and I stand corrected on the BM42 mixup by the Iraqis in the Gulf war....and no I do not underestimate the complexities of a FSAPDS.....but I am unable to fathom why did we not pester the Ruskies for the composite sabot BM46 (or the likes of the newer gen rounds) and decided in for the supply of the older BM42 from Russia.......Yes the DRDO is busy developing a new penetrator for the 125mm smooth bore (and has one in place for the Arjun 120mm Rifled gun -although I feel what we need in the next Arjun variant is a longer and better FSAPDS round on the lines of German DM-53), but is it worth having a 'not so superior' round as a stopgap till the time the production starts at DRDO to fill the void...beats me!


The BM46 is clearly not in series production.
The DRDO is not merely developing a new penetrator for the 125mm, it will be a new round. One change means changes elsewhere as well.
The original Arjun 120mm rifled round is actually behind even the 125mm ARDE MK2 that was developed (the same 125mm that is being modified further).
The 120mm round was developed around the late 90's and entered production around 2000-01, its a decade old by now and is clearly to be replaced by a new round being developed in parallel (with minimum publicity).

The IA is getting around the lack of a truly modern round on the T series fleet via massive import/license production of INVAR (3UBK-20) missiles.

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Re: Artillery Discussion Thread

Postby Sagar G » 19 Oct 2013 00:20

rohitvats wrote:Now, what would be the answer to these questions:

- MDNL LOI to OFB specifically mentioned the temperature at different stages of process for the barrel - So, on what authority did OFB deviate from the process?

- If MDNL knew about the temperature requirement and specifically mentioned the same, on what basis is the claim being made that the process for manufacturing barrels was obtained only after rounds of consultations with Russians?

- If the barrel was found to be faulty on inspection of manufacturing process by QA team, why did OFB continue with the same process? And this when the BUYER had mentioned a particular temperature range?


Let's assume that you are right and OF is totally at fault in here so all this is before 2000 by which they were doing the heat treatment as per the documents now as I said earlier this should have solved the problem no but between 03-06, 26 cases of barrel burst occurred (14 with imported barrels and 12 with indigenous barrels) as replied by Rao Inderjit Singh minister of state for defence production (link given by Kanson). So why even after heat treating as per specs were the barrels bursting.

Before you say that it was due to faulty ammunition let me point out as well what was done to fix the same,

(d) Cases of premature failure/barrel burst have been thoroughly investigated, and the opinion of Russian experts was also sought by Ministry of Defence. The suggested improvements in manufacturing process have been implemented. Some barrels, which were suspected to be defective were segregated and utilized for proof of ammunition only


There is no mention of defective ammo causing barrel burst.

Even the recent "1500 Cr. fix" is being sold on the line that due to faulty ammo T-72 barrel bursts and hence we will be buying T-90 barrel. Please point me out to any open trustable source that the T-90 barrel is strong enough to withstand an internal ammo burst. How come changing the gun barrel will solve faulty ammo problem ???

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Re: Artillery Discussion Thread

Postby Karan M » 19 Oct 2013 00:24

rohitvats wrote:
Karan M wrote:<SNIP>

Exactly. That is what is also indicated in the article by RSundaram - combining what RS and CAG say, OFB took a very risky (and IMHO incorrect) way out by asking for relaxed specs to match whatever they had in terms of machinery (OFB is usually rushing to get things into production to meet quota, QA be darned) and got "some Russians" to sign off on it. They then used this as a counter to get DGQA guys to agree to it. Apparently though, the Russian guys whom OFB cites were not the right folks (and did not include the actual designers/manufacturers of the gun barrels) and the whole mess escalated. Or the protocol was hazy on tempering temperatures (which I doubt since otherwise how would DGQA have the data) and OFB played it fast and loose. Eitherways, this is one more of a long series of OFB mess ups in QA in their rush to meet production schedules exacerbated by the Russian's and their reluctance to assist unless pushed (per RSundaram).


Well, the funny thing in this case is that the BUYER - Mishra Dhatu Nigam Limited - asked in Letter of Intent (LOI) to use 500+ degree temperature for the barrels.

Here is the excerpt from the same 2001 CAG report:

The letter of intent envisaged that the tempering of barrels would be carried out in two stages viz. in first stage in the temperature range of 520-550°C and in the second stage in the temperature range of 530-570°C


So, on what authority did OFB not follow BUYERS instructions? And why are Russians being blamed?


Thats the thing. OFB claims that it had a waiver from the Russians based on the revised protocol agreement. MIDHANI would have asked for the data per the original agreement. OFB then went and got the clearance from the Russian side because it lacked the machinery.

R Sundaram indicates that the Russians had to be armtwisted to provide more details and Agupta's recollection is another data point.

OFB is clearly to be blamed for taking the easy way out. But the Russians are also infamous in the entire DPSU/OFB sector (talk to anyone for umpteen such cases) of withholding information &/or washing their hands off of anything that doesn't quite work out.

As matter of fact, this method suits them because the more such issues occur, the more local production intent suffers and orders get placed back on Russian houses.

As matter of fact, I can confirm that the TOT for the T-72M1 itself never quite went through completely. Whether it was the SU breakdown or the agreement itself did not have TOT - but things like rubber assemblies (vital for the tank) and tracks - these were still sought to be indigenized locally - and we had no tech transfer from Russia to cover them either.

So did Russian intransigence worsen the situation/ happen for sure in this case? That I don't know. But R Sundaram is an authoritative source & judging by past behaviour of the Russian side, its plausible.

Of course, OFB has a history of seeking such "easy work arounds" e.g. tempering at less temperature etc to meet production quotas and then usually finds itself in hot water. So its a systemic issue at their end as well (and that at other DPSUs like HAL as well - read the recent IAF report of last moment/financial year end rushed work syndrome). The IMI round issue also shows that even before the faults in the first batch were rectified (which should have been IMI responsibility as well), OFB rushed to order further assemblies to meet production goals.

That is the biggest driver of this problem. Their tendency to get things done, irrespective of what the end result is.

Another thing - in this case, at least the DGQA was the certification/quality audit authority. Another "wise" idea that has been implemented in recent years to speed up production is "self certification" at the OFB factory level itself (as i remember). Keeping this event in mind, I can only wonder what will happen when the TOT provider is sitting in Russia and cannot enforce QA at the shop floor itself. Or won't.

For instance - lets see the recent T-90 story. With TOT holdups impacting production and hence induction. IA went and purchased more CKD/SKD tanks direct from source.

Russia is hence laughing all the way to the bank.

So, this event is actually a microsm of all that is wrong with our DPSU-TOT story. A manufacturer with misplaced priorities (produce fast versus produce right), obsolescent infrastructure (can't even temper at the right temperature), a TOT provider who is reported to be hard to deal with, and a system which does not provide transparent information about lessons learnt or measures undertaken to solve the problem (e.g. Project MAPLE what happened to it)..
Last edited by Karan M on 19 Oct 2013 00:29, edited 1 time in total.

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Re: Artillery Discussion Thread

Postby ramana » 19 Oct 2013 00:27

Was there confusion due to different raw steel suppliers? MDNL and the unnamde Russian?

The process ToT would be for the Russian steel supplier and using MDNL steel with those specs would not be correct.

BTW second heating is called 'drawing the temper'.

Looks like OFB was using MDNL steel with Russian TOT instructions.

And MDNL had no clout to enforce its LOI to OFB as some other agency was the enforcing agency.

Now a crucial question what are the inspection process at MDNL to supply high quality defect free hot rolled rods? Do they do vaccum arc remelt the steel and then roll only the mid-section of the ingot and UT inspect the bars for inclusions prior to shipping to OFB?

Reason is slag inclusions can ruin the day.

When alloy steel is remelted even in vacuum furnace, the refractory walls flake off and get into the melt. However they float to the top and usually are near the walls. So the fix is take the ingot and slice it to get the core section and saw off the top and bottom and inspect for inclusions. And then roll it.
Quite expensive but needed.

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Re: Artillery Discussion Thread

Postby Sagar G » 19 Oct 2013 00:27

rohitvats wrote:So, on what authority did OFB not follow BUYERS instructions? And why are Russians being blamed?


Since when did T-72 tank barrel became indigenous ??? The heat treatment process was supplied by Russians but OF said that

the protocol signed by it with Russian team in 1985, permitted the heat treatment at lower range.


Nowhere in the report has CAG contradicted this and said that there was none. Also the same was said to DGQA and they haven't as well said that OF was lying.

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Re: Artillery Discussion Thread

Postby Karan M » 19 Oct 2013 00:53

Actually, seeing this case, and the IMI round case (both of which are clearly the tip of a very large iceberg IMO) it makes sense that the MOD is insisting upon Dassault being responsible for the quality of the aircraft produced under TOT at HAL as well, and why Dassault is seeking to wriggle out of it. Dassault will be forced to get its hands dirty and ensure every process at the HAL side is checked out and maintain quality.
In the past, hard to make items revert back to OEM (making a farce out of TOT).
And if the OEM is forced to be involved at every stage (and corresponding enforcement is done at the DPSU end), the TOT situation may actually improve. Hitherto, it seems we have been reverse engineering items which we don't understand or cannot make.

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Re: Artillery Discussion Thread

Postby Karan M » 19 Oct 2013 00:57

Sagar G wrote:Now to remind ourselves of the current "fix"


This news report is mixing up too different things - the journo added 2+2=5:

India to replace bursting T-72 tank barrels under Rs 1,500 cr deal with Russia

NEW DELHI: Seeking to address the issue of bursting barrels of Army tanks due to ammunition, the government is planning to replace them with canons of T-90 tanks in collaboration with Russia.

T-72 tanks, the mainstay of the Indian armoured fleet, are facing problems with their ammunition as they sometimes burst in the barrel and 200 such cases have been reported causing concern in the Army.

The Defence Ministry is planning to replace the barrels of the T-72 tanks with the ones fitted in the T-90 tanks. Under the plan, around 800 barrels are to be procured from Russia under a deal expected to be worth around Rs 1,500 crore, government sources told PTI here.

The issue is expected to be taken up for discussion during the high-level talks between India and Russia during the visit of Defence Secretary Radha Kant Mathur to Moscow next week, they said.


So because the latest Russian barrels are better OR Maple didn't come through. Even if Maple was a failure, it doesn't explain why we are doing this if we already have our local T-90 barrel.

Curiouser and curiouser.

Earlier this year, the Army told a Parliamentary panel that barrels burst sometimes due to ammunition and wondered whether its troops will be "afraid" to fire even after seeing the enemy.

"It (the T-72 ammunition) used to burst in the barrel. If it bursts in the barrel, then the firer is afraid to fire his own gun, which is not a correct thing. If he is afraid to fire his own gun, then even if he sees the enemy he will not fire," the Army had told the Standing Committee on Defence.

The Army informed the government and the Parliamentary Committee that over a period of time, there have been 200 such accidents involving the ammunition and "it brings down the confidence of the firer, especially, with regard to tank ammunition".
.
[/quote]

This is a reference to the rounds which had leaking propellant and which became unstable when stored in heat. As matter of fact, those 200 such incidents were not merely barrel bursts, a propellant leak means that the propellant could spill anywhere within the fighting compartment of the T-72 and as it lacks separation of ammo and crew, that means entire turret can go up. I remember reading that, we lost a tank or two like this.

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Re: Artillery Discussion Thread

Postby rohitvats » 19 Oct 2013 01:01

Karan M wrote:<SNIP>

Thanks for the details.

Judging by the points made by SagarG - the problem does persist.

I wonder whether it is also an ammunition compatibility issue. Need to dig up the chamber pressures for the respective ammo's, fielded by India.


Karan - quite a coincidence that you should mention Chamber Pressure issue and ammunition compatibility.

The same article by RS in the Hindu states that 'Army feels' the barrel bursts in 2003-2006 period happened due to indigenous ammunition - this is what he said:

Meanwhile, the Army appears to believe that one of the causes may be the strength of explosives in the ingenuously produced high explosive ammunition


The good author does not even want to inquire about this line of reasoning - that may be there is truth in it. But doing so would mean that OFB screwed up in another department after the initial barrel fiasco.

Now - if the Army feels that T-90 barrel is the solution - then IMO it can mean that this gun can withstand the higher chamber pressure of rounds - especially the AFPSDS.

--------------------------------------------------------------------------------------------------------------------------------

However, there is an interesting stat I discovered:

(from Fofanov)
T-72B - Gun 2A46M: Chamber Pressure - 5100 bar
T-90A - Gun 2A46M-5: Chamber Pressure - 6500 bar

(from tank net)
IMI CL-3254 APFSDS - Chamber Pressure (nominal) - 570 MPa or 5700 bar.

Interesting, no?

--------------------------------------------------------------------------------------------------------------------------------

http://articles.economictimes.indiatimes.com/2013-08-28/news/41538730_1_t-72-tanks-tank-ammunition-t-90-tanks

The ET report confuses the matter - for example:

T-72 tanks, the mainstay of the Indian armoured fleet, are facing problems with their ammunition as they sometimes burst in the barrel and 200 such cases have been reported causing concern in the Army.


Well, if the ammunition burst is causing the problem, then how will replacing original canon with T-90 ones solve the issue?

IMO - this is a case of DDM and the issue is with respect to ammunition compatibility with the canon at hand.

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Re: Artillery Discussion Thread

Postby Sagar G » 19 Oct 2013 01:05

Karan my first thoughts as well that it's plain old DDM. Forget about why we are doing this when we have developed local T-90 barrel but why the hell we are doing this when we have developed an entire bloody tank around the barrel ???

Who is making those leaking ammo by the way ???

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Re: Artillery Discussion Thread

Postby rohitvats » 19 Oct 2013 01:08

Sagar G wrote:
rohitvats wrote:So, on what authority did OFB not follow BUYERS instructions? And why are Russians being blamed?


Since when did T-72 tank barrel became indigenous ??? The heat treatment process was supplied by Russians but OF said that

the protocol signed by it with Russian team in 1985, permitted the heat treatment at lower range.


Nowhere in the report has CAG contradicted this and said that there was none. Also the same was said to DGQA and they haven't as well said that OF was lying.


I asked a simple question - How come the BUYER who placed an indent mentioned the right temperature and process?

And what is the standing of OFB on signing protocol with someone who was proved to NOT be the OEM?

After all, the so called protocol which OFB signed proved to be faulty and led to the whole issue - and they persisted with this faulty process even when the sample product proved to not meet the requirement.

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Re: Artillery Discussion Thread

Postby Karan M » 19 Oct 2013 01:10

1. This clearly shows that a protocol was signed in 1985 and somehow, it "missed including the original designer"... seems a perfect case of right hand not knowing what the left hand was doing at both OFB and Russian end. Who exactly signed off on this protocol then from the Russian side?

2. Be as it may, it also shows the chalta hain attitude of FGF Kanpur - when a barrel cracked during straightening process, should they not have explored the matter further and determined the cause? No, they went ahead post haste. Why? Its pretty clear, because: Ordnance Factory Board stated in August 1998 that reduced band of heating during tempering was a modification in the technological process to suit Indian conditions of available plant and machinery

So basically get the production done, irrespective of how the outcome is.

I think its high time, the DPSU complex is firmly made to understand that just to meet production quotas and get their "overtime"/meet yearly quota, they cannot take the easy way out.

The Russian bait and switch as seems evident from above (1) and RSundaram's points - is another case entirely, and cannot be solved easily. We have to play hardball with them, and perhaps even drop deals with them, if TOT is not properly transferred.

Big question here. If TOT envisages transfer of process and BOM for both manufacturing equipment and raw materials, how did OFB not have the proper gear to make these barrels? Seems yet another case of TOT on paper or underinvestment on Indian side in proper infrastructure.


20. Rejection of barrels manufactured for T-72 tanks

Director General Ordnance Factories deviated from manufacturing technique without consulting the original designer. This resulted in defective manufacture of barrels valued at Rs 45.07 crore affecting the performance of T-72 tanks.

Director General Ordnance Factories manufactured 770 barrels for T-72 tanks deviating from critical heat treatment schedule for tempering of barrels without consulting the original designer. This resulted in manufacture of defective barrels. 11 barrels burst in firing from tanks causing accidents. 454 defective barrels valued at Rs 44 crore were held in stock and the remaining 305 barrels fitted in the tanks were under process of investigation as of June 1999. The case is as under:
DDPS placed order on MIDHANI for supply of 774 barrels

Department of Defence Production and Supplies placed an order on Mishra Dhatu Nigam Limited., Hyderabad in October 1989 for supply of 774 barrels to be fitted in T-72 tanks, at a cost of Rs 67.73 crore. Mishra Dhatu Nigam Limited, in turn, placed a letter of intent in March 1990 on Director General Ordnance Factories for converting black forging hot rolled bars i.e. input raw materials into finished, machined and tested barrels. The letter of intent envisaged that the tempering of barrels would be carried out in two stages viz. in first stage in the temperature range of 520-550�C and in the second stage in the temperature range of 530-570�C. The barrels were to be supplied by the Director General Ordnance Factories to Central Ordnance Depot Jabalpur only after testing by Controllerate of Quality Assurance (weapons) Jabalpur.
MIDHANI placed a letter of intent on DGOF for converting forgings into barrels

The responsibility for quality assurance of items manufactured in Ordnance factories rests with the manufacturing factory. Director General Quality Assurance and Inspectorates under him are responsible for surveillance, quality audit and final acceptance inspection. In surveillance check of barrels during manufacture in Field Gun Factory, Kanpur in 1990, when one of the barrels broke in the straightening operation, the Quality Assurance Establishment (Field Gun), notified the Factory that to avoid such breakage, the heat treatment should be carried out at 520�C-570�C as provided by designer. The Field Gun Factory Kanpur however, continued tempering the forgings at reduced temperature even below 430�C, on the plea that the protocol signed by it with Russian team in 1985, permitted the heat treatment at lower range.

One barrel broke in FGF, Kanpur
QAE(FG) pointed out that heat treatment should be at 520�C -570�C
FGF Kanpur continued tempering the forgings at temperature below 430�C

Field Gun Factory supplied 770 barrels to the Central Ordnance Depot Jabalpur between 1992 and 1996. The Quality Assurance Establishment had, however, passed these barrels despite their tempering at reduced temperature, as fit for use. Department of Defence Production and Supplies paid Rs 74.67 crore inclusive of price escalation to Mishra Dattu Nigam Limited.
11 barrels cracked/ burst during firing causing accidents
Foreign specialists attributed accidents to deviation in tempering temperature
Army decided in December 1997 to withdraw all the barrels

During firing in September 1992, from a T-72 tank, the barrel cracked causing an accident. Further in 35 more accidents occurred till March 1998, ten more barrels cracked/burst. Russian specialists, who investigated the cause(s) of the accidents, observed that the deviation from prescribed tempering temperature was the direct cause of such breakages, and that the protocol signed in 1985 was without consulting the original designer.

Army Headquarters decided in December 1997 to withdraw all barrels tempered at 460�C and below. As of June 1998, 454 such barrels valued at Rs 44 crore from stock were identified and rejected and remaining 305 barrels fitted on tanks were under investigation. Tempering of barrels were now being done at temperatures above 500�C.

In response to Audit observation, Ordnance Factory Board stated in August 1998 that reduced band of heating during tempering was a modification in the technological process to suit Indian conditions of available plant and machinery. The reply is not acceptable since the modification was done without consulting the original designer and subsequent accidents had been directly ascribed to this.

The matter was referred to the Ministry in September 1999; their reply was awaited as of December 1999.

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Re: Artillery Discussion Thread

Postby Sagar G » 19 Oct 2013 01:18

rohitvats wrote:I asked a simple question - How come the BUYER who placed an indent mentioned the right temperature and process?


Reading about Midhani only confuses the situation more I mean why did DDPS place an order for 774 barrels on Midhani ??? AFAIK Midhani doesn't manufacture barrels it only supplies raw material which it did and mentioned the heat treatment process but T-72 tank barrel isn't of indigenous origin so how come they are supplying the raw material and mentioning the heat treatment process ???

rohitvats wrote:And what is the standing of OFB on signing protocol with someone who was proved to NOT be the OEM?


"Proved" ??? Without any substantial evidence you are using that word the CAG report states that

Russian specialists, who investigated the cause(s) of the accidents, observed that the deviation from prescribed tempering temperature was the direct cause of such breakages, and that the protocol signed in 1985 was without consulting the original designer.


So it's the Russians only who are saying that and OF doesn't have the authority to go ahead and sign defence deal with any tom dick and harry without the MoD nodding it.

rohitvats wrote:After all, the so called protocol which OFB signed proved to be faulty and led to the whole issue - and they persisted with this faulty process even when the sample product proved to not meet the requirement.


And for that OF is totally at fault nobody argues that but take a look at what happened later and now please answer my simple questions regarding the 03-06 time frame barrel bursts.

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Re: Artillery Discussion Thread

Postby Sagar G » 19 Oct 2013 01:22

But Karan even after doing all what the Russians said we are only going to pour 1500 cr. more to fix the damn t-72 barrels, WTF ???

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Re: Artillery Discussion Thread

Postby Karan M » 19 Oct 2013 01:28

rohitvats wrote:Karan - quite a coincidence that you should mention Chamber Pressure issue and ammunition compatibility.

The same article by RS in the Hindu states that 'Army feels' the barrel bursts in 2003-2006 period happened due to indigenous ammunition - this is what he said:

Meanwhile, the Army appears to believe that one of the causes may be the strength of explosives in the ingenuously produced high explosive ammunition


The good author does not even want to inquire about this line of reasoning - that may be there is truth in it. But doing so would mean that OFB screwed up in another department after the initial barrel fiasco.

Now - if the Army feels that T-90 barrel is the solution - then IMO it can mean that this gun can withstand the higher chamber pressure of rounds - especially the AFPSDS.

--------------------------------------------------------------------------------------------------------------------------------

However, there is an interesting stat I discovered:

(from Fofanov)
T-72B - Gun 2A46M: Chamber Pressure - 5100 bar
T-90A - Gun 2A46M-5: Chamber Pressure - 6500 bar

(from tank net)
IMI CL-3254 APFSDS - Chamber Pressure (nominal) - 570 MPa or 5700 bar.

Interesting, no?


It is interesting and could be a good reason for the shift to T-90 gun barrel.

So basically we have the "perfect storm" of multiple drivers causing a single issue (barrel explosions).

1. Circa 1990's-1999:
Ammo in IA service - Russian rounds/ ARDE MK1 FSAPDS/Hybrid ARDE/OFB FSAPDS
ARDE MK1/Hybrid FSAPDS leak in service - explosions in tank/ barrel burst
Barrel bursts of T-72 even otherwise
Rounds withdrawn from service circa 2000
Barrels: Improper heat tempering ----> rectified @ 1999

2.1999-2001 - IA inducts IMI CL3254

3. 2003-06:
Meanwhile imported/ new local barrels continue to burst.
Ammo in service: IMI CL3254, Russian BM42 (around 2005, IMI rounds begin assembly at OFB)

4. 2006 - Maple program - 2 T-72 barrels to IMI for round checking/propellant modification (indicates round compatibility issue is being addressed)

5. 2011 - OFB reports has its own T-90 barrel (ref: Shukla). Interestingly (somewhat OT) T-90s can only use BM42 (as original BallComp is not compatible with CL3254)

6. 2012 - reports of IA inducting T-90 barrels from Russia for T-72 (so what the heck are T-90s using?)

So would round incompatibility be overlooked by the IA or even OFB. Because in 2006, Project Maple supplied 2 barrels to IMI exactly for propellant development. Could it be that they too figured this out and hence intended to move to newer barrels? And Maple didn't work out, so it made sense to simply standardize on the latest T-90 level barrel..

So India will have to do all the testing and validation for ensuring CL3254 (which is anyways going to be retired one day, 46K rounds will last only so long) will work with latest 2A46M variant to be fitted on T-72.

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Re: Artillery Discussion Thread

Postby Karan M » 19 Oct 2013 01:38

This is what MAPLE notes:

Circa 2006

Indigenisation of 125mm t-90 ordnance

1 No. indigenous T-90 barrel is under assembly with OEM breech mechanism. It is proposed to subject this barrel to life cycle test (250 rounds) for ascertaining the suitability of indigenous steel. The article 2A46M will be offered for life cycle test at PXE Balasore by end of July 2006. Further 2 Nos of T-90 ordnance will be produced with GOST specification steel during 2006-07.

125MM MAPLE Barrel ((MATERIAL ADDED AUTOFRETTAGE PROCESS LEADING TO ELASTIC RELEASE)

This barrel is offered as alternative to 125mm SB T-72 barrel. Combining the benefits of auto-frettaged and shrink fit designs, it offers various advantages over OEM T-72 barrel.

These include higher maximum safe pressure (800 MPA as compared to 670 MPA in
T-72 barrel), higher fatigue life of barrel (1700 EFC as compared to 250 EFC for T-72 barrel).
It is planned to manufacture and supply 2 Nos. of these barrels by Sept 2006 for trial and evaluation.

STATUS :
2 barrels successfully proven and issued to imi israel for fsapds propellant development. 2 more barrels are expected to be ready by sept 2006 for user trial at ACCC&S Ahmednagar.


Find it surprising that the MPA mentioned is higher than that of the tank gun for the T-90..
Ah darn, now to dig out Russian sources..

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Re: Artillery Discussion Thread

Postby Sagar G » 19 Oct 2013 01:52

These include higher maximum safe pressure (800 MPA as compared to 670 MPA in T-72 barrel), higher fatigue life of barrel (1700 EFC as compared to 250 EFC for T-72 barrel).


Beats the 2A46M hands down.

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Re: Artillery Discussion Thread

Postby Karan M » 19 Oct 2013 01:56

This indicates that starting 1981, T-72 tank guns could sustain 650MPA, 6500 bar. Note this is chamber pressure max, and rounds can be at lower pressures.
http://fofanov.armor.kiev.ua/Tanks/ARM/2a46.html

So the MAPLE snippet above could be accurate. We procured T-72s over the 90's.

Interestingly, the Arjun gun can take upt 612MPA (6120bar), but the (older) round is only upto 510MPA

Round (note 125mm MK1 and MK2 as well)
http://img846.imageshack.us/img846/8168/scan0078q.jpg

Gun
http://drdo.gov.in/drdo/pub/techfocus/feb02/arjun.htm

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Re: Artillery Discussion Thread

Postby rohitvats » 19 Oct 2013 02:01

Karan M wrote:<SNIP>Find it surprising that the MPA mentioned is higher than that of the tank gun for the T-90..
Ah darn, now to dig out Russian sources..


I have been wanting to do a detailed article on tank ammunition situation in India - guess now is the good time. Have been collecting some data...your posts will be of great help. Will send you draft for inputs once it is ready.


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