Artillery: News & Discussion

srai · Post by **srai** » 22 Jul 2017 05:29

^^^
The way this whole Dhanush saga is unfolding doubt it will be inducted anytime soon or in the quantities planned. Similar fate for ATAGS?

suryag · Post by **suryag** » 22 Jul 2017 05:34

What do you think will happen different with ATAGS? User exploitation trials followed by division exploitation trials followed by brigade exploitation trials and so on

ramana · Post by **ramana** » 22 Jul 2017 05:44

Did the shell explode in this recent trial?

Any data?

ArjunPandit · Post by **ArjunPandit** » 22 Jul 2017 05:45

OFB has close to 1,40,000 employees (wiki). That's a huge no.. while not a good comparison but many fortune 100 companies will not be having this employee count. This is where having a full time defence minister like MP would help.

ramana · Post by **ramana** » 22 Jul 2017 06:13

We have an OFB and DPSU thread .
Let's focus on Dhanush.
Being engineers will learn a lot.

srai · Post by **srai** » 22 Jul 2017 07:56

suryag wrote:What do you think will happen different with ATAGS? User exploitation trials followed by division exploitation trials followed by brigade exploitation trials and so on

If this happened to the imported ULH during exploitation phase (meaning contract already signed and deliveries have begun), would the IA have the authority to tell BAE to make changes and stop production before further can be inducted? Don't think so. They will have to induct all and work with the limitation. Down the road, they will need to pay for modifications.

Singha · Post by **Singha** » 22 Jul 2017 08:17

Adour 804->Adour 811 saga of jaguar.
200 JSF are flying all over today with various limitations and updates still due.
identify the problem, find the soln, make sure its not life threatening to the crew but we'd be shooting ourself in the head if we delay Dhanush by years over this.

why exactly would a 61m fuse be needed for a indirect fire howitzer except a last ditch 'fire over open sights' to prevent infantry attack on their position? that is more a direct fire mode for field cannons .

deejay · Post by **deejay** » 22 Jul 2017 08:37

srai wrote:
suryag wrote:What do you think will happen different with ATAGS? User exploitation trials followed by division exploitation trials followed by brigade exploitation trials and so on
If this happened to the imported ULH during exploitation phase (meaning contract already signed and deliveries have begun), would the IA have the authority to tell BAE to make changes and stop production before further can be inducted? Don't think so. They will have to induct all and work with the limitation. Down the road, they will need to pay for modifications.

The answer is - Yes. If the contracts are properly drafted.

However, this a very interesting post. It goes into a hypothetical situation...

would the IA have the authority to tell BAE to make changes and stop production before further can be inducted?...

and then gives a definitive answer...

... Don't think so. They will have to induct all and work with the limitation. Down the road, they will need to pay for modifications.

Brilliant.

Singha · Post by **Singha** » 22 Jul 2017 08:46

considering our track record of weak contracts ranging from jaguar 804 saga, TOT for T90 , talwar ship radar problems and umpteen russi systems that needed time/money/lives for us to fix, you should excuse him for lungi shivering.

the one instance where it seems full and final TOT was given - Bofors - OFB sat on it for 20 years

deejay · Post by **deejay** » 22 Jul 2017 08:56

I am not here to fault the individual but there is something missing in these discussions. Since the news came, I was hoping for one post to say something like this " Shite!, a 155mm 45 cal arty shell exploded near at least 10 men. Hope they are ok."

The experience of an arty shell exploding in close proximity is quite something people. If the gun has a problem let it be rectified. Given that none of us control the system which will decide, we will have to wait and watch what happens.

shiv · Post by **shiv** » 22 Jul 2017 09:08

deejay wrote:I am not here to fault the individual but there is something missing in these discussions. Since the news came, I was hoping for one post to say something like this " Shite!, a 155mm 45 cal arty shell exploded near at least 10 men. Hope they are ok."

The experience of an arty shell exploding in close proximity is quite something people. If the gun has a problem let it be rectified. Given that none of us control the system which will decide, we will have to wait and watch what happens.

We need a separate dedicated thread or forum for people who know versus the people who have information.

Karan M · Post by **Karan M** » 22 Jul 2017 09:44

deejay wrote:I am not here to fault the individual but there is something missing in these discussions. Since the news came, I was hoping for one post to say something like this " Shite!, a 155mm 45 cal arty shell exploded near at least 10 men. Hope they are ok."

The experience of an arty shell exploding in close proximity is quite something people. If the gun has a problem let it be rectified. Given that none of us control the system which will decide, we will have to wait and watch what happens.

I believe they will be firing the gun with a long lanyard with the men located behind the gun a bit far away, so hopefully, they should be ok. That's standard practise AFAIK with all these systems in trials. But even so, a 155mm airburst is what this is amounts to, very dangerous and scary.
Regarding barrel bursts, OFB, T-72s also had those, because OFB did not temper the barrels properly.

Karan M · Post by **Karan M** » 22 Jul 2017 09:49

As long as OFB is not involved as the key player in ATAGS that gun should do ok. OFB makes the 155mm ammo and even that should ideally be moved to private sector or even BDL.

ramana · Post by **ramana** » 22 Jul 2017 11:14

deejay wrote:I am not here to fault the individual but there is something missing in these discussions. Since the news came, I was hoping for one post to say something like this " Shite!, a 155mm 45 cal arty shell exploded near at least 10 men. Hope they are ok."

The experience of an arty shell exploding in close proximity is quite something people. If the gun has a problem let it be rectified. Given that none of us control the system which will decide, we will have to wait and watch what happens.

Deejay, Yes first concern should be safety of the artillerymen. Fortunately the press did not report any injuries. I think the gunners also have ear protection but only for gun firing and not shell burst. Yes the shock must have been severe.

ramana · Post by **ramana** » 22 Jul 2017 11:50

I read about dozen reports on Fuze, barrel design and failure reports from the web.

The Fuze Point Detonation (PD) M 572 is a US design and is derived from a WWII fuze called M48A.
The fuze has super quick mode and delay action mode. During World War I looking at battlefield casualties, they realized that the shell should burst as it hits the ground to fragment. Hence this Super Quick mode. When set in this mode it overrides the delay action which is to give a short delay for penetration. M572 has safing and arming features. Its safe and wont fire unless the spin rate is minimum 2000 rpm. It has mechanical segmented rotors which disengage and arm it above that spin rate. It has detents to prevent them from unlocking in case of deceleration. Generally this occurs at a distance of 61 m or 200 feet. However the scribd document linked by tsarkar says that 45 caliber barrels sometimes get armed by the time they emerge from the barrel. Don't know why? Could be more acceleration developed in the longer barrel? Point of all this is the fuze could be sensitive.
BTW OFB is not the only maker of the fuzes in India.

Barrel burst phenomena

Barrels are like extra thick pressure vessels subject to dynamic pressures from the charge being set off. This causes a tension stress wave to develop in the hoop direction of the barrel. This tension stress wave should be less then the yield and ultimate strength of the materials. The Germans, figured out if there is pre-stress of compression then the charge could be increased to propel the shell farther. This process is called auto-frettage. Initially it was done by high pressure oil that creates a plastic deformation stress which on relieving the hydro pressure creates a compression stress field in the barrel. Think of this as a a wire rope or hoops around the barrel. A process improvement was a mechanical rotary hammers which set up the compression stress field more consistently.
The repeated firings cause fatigue in the barrel material and after a certain number it could fail catastrophically. Again any stress concentration aggravates the situation. E.g change in barrel diameter between chamber and the straight portion. Periodic over-stress could set up micro-cracks which could grow eventually and shatter the barrel. Here the material fracture toughness and the critical crack length are important. So the material has to be high yield and ultimate strength, high fracture toughness which comes from high ductility to prevent cracks from shattering the barrel. Machining has to be very good to prevent surface finish crack starters, the auto-frettage perfect to give it adequate strength. Above all design to ensure high rate of fire. You can Google for reports on 175mm guns failure and see how the barrel shatters under high rate of fire. To me the fascinating thing is the relation off low cycle fatigue from high stress levels. We see this in aircraft structures.

Trikaal · Post by **Trikaal** » 22 Jul 2017 11:55

http://www.firstpost.com/india/cbi-find ... 42579.html

Real reason of gun failure. When u hv traitors like these GCF officials, who needs enemies ? With such people incharge of our weapon manufacturing, I am afraid even preparation for 2.5 fronts isn't enough

archan · Post by **archan** » 22 Jul 2017 12:18

^^ please select a human sounding username and let us know. We will change your user ID and later remove these OT posts from the thread.

niran · Post by **niran** » 22 Jul 2017 12:55

Singha wrote:considering our track record of weak contracts ranging from jaguar 804 saga, TOT for T90 , talwar ship radar problems and umpteen russi systems that needed time/money/lives for us to fix, you should excuse him for lungi shivering.

the one instance where it seems full and final TOT was given - Bofors - OFB sat on it for 20 years

OFB received full blueprints 20 years later sir not their fault

niran · Post by **niran** » 22 Jul 2017 13:02

deejay wrote:I am not here to fault the individual but there is something missing in these discussions. Since the news came, I was hoping for one post to say something like this " Shite!, a 155mm 45 cal arty shell exploded near at least 10 men. Hope they are ok."

The experience of an arty shell exploding in close proximity is quite something people. If the gun has a problem let it be rectified. Given that none of us control the system which will decide, we will have to wait and watch what happens.

total 13 personal injured
A-all 13 suffered blown Tympanic membrane(the membrane inside ears )
B-11 Brain concussion out of which 2 are still under observation and treatment
C-2 pulmonary concussion the 2 in "B"
D- 2 suffered ruptured intestines (thank Mahadev for small mercies it was not Liver or other such organs) the 2 in "B"
so 2 are serious 11 discharged

ashish raval · Post by **ashish raval** » 22 Jul 2017 13:06

Third Dash wrote:http://www.firstpost.com/india/cbi-find ... 42579.html

Real reason of gun failure. When u hv traitors like these GCF officials, who needs enemies ? With such people incharge of our weapon manufacturing, I am afraid even preparation for 2.5 fronts isn't enough

They should be tried in military court and corporal punishment to sabotage defense preparedness and working for enemy subject should be lodged to put dagger of dear into whoever Feb remotely thinks about doing such thing again.

Karan M · Post by **Karan M** » 22 Jul 2017 13:15

niran wrote:
deejay wrote:I am not here to fault the individual but there is something missing in these discussions. Since the news came, I was hoping for one post to say something like this " Shite!, a 155mm 45 cal arty shell exploded near at least 10 men. Hope they are ok."

The experience of an arty shell exploding in close proximity is quite something people. If the gun has a problem let it be rectified. Given that none of us control the system which will decide, we will have to wait and watch what happens.
total 13 personal injured
A-all 13 suffered blown Tympanic membrane(the membrane inside ears )
B-11 Brain concussion out of which 2 are still under observation and treatment
C-2 pulmonary concussion the 2 in "B"
D- 2 suffered ruptured intestines (thank Mahadev for small mercies it was not Liver or other such organs) the 2 in "B"
so 2 are serious 11 discharged

this is horrible news. so for all practical purposes, an entire section has been gravely wounded.

so literally like an airburst , but no shrapnel injuries, thank God.

now with what rationale can OFB claim all iz well????

Karan M · Post by **Karan M** » 22 Jul 2017 13:18

so those 2 people in B were nearest to the gun?? after this please tell me how can anyone state OFB does not need severe reorganization. issues with QA are very well known.

Trikaal · Post by **Trikaal** » 22 Jul 2017 13:30

niran wrote:
deejay wrote:I am not here to fault the individual but there is something missing in these discussions. Since the news came, I was hoping for one post to say something like this " Shite!, a 155mm 45 cal arty shell exploded near at least 10 men. Hope they are ok."

The experience of an arty shell exploding in close proximity is quite something people. If the gun has a problem let it be rectified. Given that none of us control the system which will decide, we will have to wait and watch what happens.
total 13 personal injured
A-all 13 suffered blown Tympanic membrane(the membrane inside ears )
B-11 Brain concussion out of which 2 are still under observation and treatment
C-2 pulmonary concussion the 2 in "B"
D- 2 suffered ruptured intestines (thank Mahadev for small mercies it was not Liver or other such organs) the 2 in "B"
so 2 are serious 11 discharged

GCF and the Delhi company people should be made to give life support compensation to these soldiers. We need to make an example out of this that nation cannot be held hostage to vested interests. Saari duniyaa mein naak katta dii hai inn logon ne. If this wasn't discovered, people would have found yet another reason to push for imports.

JayS · Post by **JayS** » 22 Jul 2017 13:33

niran wrote:
deejay wrote:I am not here to fault the individual but there is something missing in these discussions. Since the news came, I was hoping for one post to say something like this " Shite!, a 155mm 45 cal arty shell exploded near at least 10 men. Hope they are ok."

The experience of an arty shell exploding in close proximity is quite something people. If the gun has a problem let it be rectified. Given that none of us control the system which will decide, we will have to wait and watch what happens.
total 13 personal injured
A-all 13 suffered blown Tympanic membrane(the membrane inside ears )
B-11 Brain concussion out of which 2 are still under observation and treatment
C-2 pulmonary concussion the 2 in "B"
D- 2 suffered ruptured intestines (thank Mahadev for small mercies it was not Liver or other such organs) the 2 in "B"
so 2 are serious 11 discharged

Thats serious. The way reports came, impressions was no injuries to talk of as such.

Singha · Post by **Singha** » 22 Jul 2017 13:56

is it known what nakli part is the CBI enquiry problem or is that a separate issue?
pic of wire race roller bearing indicates it probably is not related to the shell issue

negi · Post by **negi** » 22 Jul 2017 13:59

Dumb question aren't there equivalent of wooden rounds for trials where a dummy sabot is fired instead of a shrapnel filled air-burst round ? A gun should be qualified for live ammo only after firing at least a couple of hundred such rounds right ?

Singha · Post by **Singha** » 22 Jul 2017 14:01

negi wrote:Dumb question aren't their equivalent of wooden rounds for trials where a dummy sabot is fired instead of a shrapnel filled air-burst round ? A gun should be qualified for live ammo only after firing at least a couple of hundred such rounds right ?

dhanush protos must have fired 1000s of rds already between them. there is no logic to have each barrel wear out half its life firing 200 wooden rounds before going live.

also user exploitation battery trial means the real shell effects on target will be studied.

Pratyush · Post by **Pratyush** » 22 Jul 2017 14:32

Ramana has been quite focused on the fuse related matter. That the fuse arms after 200 rotations.this brings up a few questions that I would like to have answers for.

1 do these shell rotate 200 times in the gun barrel it self.
2 aren't these shells supposed to detonate on impact. So in the absence of an impact. How did the Detonation happen.

srai · Post by **srai** » 22 Jul 2017 16:47

niran wrote: total 13 personal injured
A-all 13 suffered blown Tympanic membrane(the membrane inside ears )
B-11 Brain concussion out of which 2 are still under observation and treatment
C-2 pulmonary concussion the 2 in "B"
D- 2 suffered ruptured intestines (thank Mahadev for small mercies it was not Liver or other such organs) the 2 in "B"
so 2 are serious 11 discharged

Any source for this? Haven't seen it reported yet.

Singha · Post by **Singha** » 22 Jul 2017 17:01

Pratyush wrote:Ramana has been quite focused on the fuse related matter. That the fuse arms after 200 rotations.this brings up a few questions that I would like to have answers for.

1 do these shell rotate 200 times in the gun barrel it self.
2 aren't these shells supposed to detonate on impact. So in the absence of an impact. How did the Detonation happen.

Many are airburst using rf radio altimeter

srai · Post by **srai** » 22 Jul 2017 17:20

Dhanush fails at the tip again

21 Jul 2017
...
However, sources say a number of similar incidents have happened in the original 155mm Bofors guns too, despite the higher diameter in it. Even the Israeli 130mm gun upgraded to 155mm indigenously has seen similar problems. The muzzle brake in this gun has a smaller diameter as compared to Dhanush.
...
Even the guns by Soltam, an Israeli firm, has seen such problems, the source said.
...
Muzzle breach is not a new problem in artillery systems but it is certainly not desirable. There are higher chances of shell hitting the muzzle in a gun with a longer range as more power is added to the ammunition. But Bofors, which has lower range as compared to Dhanush, too was susceptible to muzzle hits. Once it happens, the shell cannot travel full range, explained a source.
...

Shell hitting muzzle impacts range from the 21 July article above. It doesn't mention shell bursting because of it. So that burst event seems to be different matter like Ramana pointing out it could be shell fuse issue.

BTW, Shell burst event happened in 27 May 2017.

Indian Bofors misfires during trials

27 May 2017
...
In the second such incident, one of the Indian guns was damaged due to an accident during test fires. Nearly a fortnight ago, as battery trials of Dhanush — the Indian gun were under way at Pokhran — the shell burst soon after ejection from the barrel, said sources.
...
This incident has pushed the process back by a month. It happens when the GCF was in the last stage of trials. The firing was part of user exploitation, which was conducted for the first time for any weapon system.

Usually, once a system is cleared through user-trials, it is inducted. "For Dhanush, user exploitation was included after user trials were over," said the sources. This means the army wanted to further use guns to get accustomed to it. Any changes required were also supposed to be suggested.
...
"A court of inquiry has been instituted into the matter after which the reasons will be ascertained. However, this has delayed the process by one more month, otherwise all the stages of trials were over. It was for the first time a batter trial was held in which six guns are fired at a time. The problem occurred in one of the guns," said the source.

The next battery trials are planned to be held in June at Pokhran. ...

People seem to be confusing two separate un-related events. They have already moved on from that May 27 premature burst event for this July trials. That event delayed next trials by one month.

Manish_Sharma · Post by **Manish_Sharma** » 22 Jul 2017 18:59

----Pooof ---

Kakarat · Post by **Kakarat** » 22 Jul 2017 19:09

Manish_Sharma wrote:
srai wrote: Any source for this? Haven't seen it reported yet.
I am sending this to Sudhir Chaudhary of Zee and Arnab Republic Channel chiding the MSM not reporting it. Maybe they we I'll acknowledge maybe not.

I urge fellow BRFites to do same.

First what is the source of information? From where did 'niran' get these details?

Manish_Sharma · Post by **Manish_Sharma** » 22 Jul 2017 19:29

Dr. Niran ji himself is the reliable source.

Indranil · Post by **Indranil** » 22 Jul 2017 20:01

You shouldn't have. Even if this is true, let GoI reveal what it needs to reveal. If IA or GoI have not spoken about it, there may be reasons.

On a different note, accidents may happen. But, criminal proceedings should become a norm for criminal neglect. If these injuries are true and if CoI comes out saying that it was because somebody's chai or lunch was getting late, OFB would have find a motivated denouncer in me.

chetak · Post by **chetak** » 22 Jul 2017 20:04

Isn't the very act of using fake cheeni made parts evidence of sabotage and anti-national activities, given the national importance of this project??

The concerned SOBs should be booked under the Sedition law.

chetak · Post by **chetak** » 22 Jul 2017 20:09

Indranil wrote:You shouldn't have. Even if this is true, let GoI reveal what it needs to reveal. If IA or GoI have not spoken about it, there may be reasons.

On a different note, accidents may happen. But, criminal proceedings should become a norm for criminal neglect. If these injuries are true and if CoI comes out saying that it was because somebody's chai or lunch was getting late, OFB would have find a motivated denouncer in me.

there is something known as the OSA (official secrets act) If someone posting here is subject to this act, the consequences can be catastrophic.

The OSA remains effective for 10 years after someone signs it or becomes subject to its provisions.

It would be my understanding that many, including civilians, would come under the provisions of the OSA for this project.

ramana · Post by **ramana** » 22 Jul 2017 20:52

Deejay and Niran, Am very sorry the entire section got injuries. This was not reported by the fake press for their own reasons. Again hope they recover and IA gives proper hearing/ear protection for the crew at-least for trials,

Guys take a look at the bearings. They are probably trunnion bearings for tilting the barrel for different elevations. In any case outside the barrel and chnaber area. So while they are a case of spurious parts or fraud they are not a contributor.

Negi Yes there are wooden rounds called practice rounds, Usually filled with flash and smoke powder to register the hits and active fuze.

Also if you look in detail at the shell it has a non-ferrous (not iron) driving band at the bottom and that engages the barrel inner diameter or bore. So the shell has a line contact along the driving band. The center of gravity is above somewhere about 40% from the base due to it being an approximate cone. When the charges behind the shell are fired this conical body held along the driving band sees a moment and it strikes the barrel sides. This is called "side slap". Now envision the side slap happening as the shell travels along the barrel. And happening at the muzzle brake as it exits the barrel.

All guns will have side slap. And you can't get rid of that as its from the driving band. What you can do is make the band thinner but that is a new shell. I think barrel wear increases the side slap consequences as there is more clearance. Further a longer barrel like 45 calibers will see more probability of side slap hitting the muzzle brake.

Chetak the fake bearings were a case of fraud. Also no state secrets were being revealed. After POK tests similar arguments were brought to muzzle discussion. (Pun intended.)

Pratyush, The fuze is M572 PD. It has two modes super quick and delay. It comes in super quick mode from factory. Super Quick mode will be primary mode over the delay function. Super quick functions in 0.05 seconds after impact.

The arming mechanism arms the fuze at minimum 2000 rpm. The 45 caliber barrel travel is most likely arming the fuze. That is my inference and putting on my thinking hat. The M572 has a graze function in the delay mechanism, that is it functions when it hits an object at an angle. Now the shell hitting the muzzle brake due to side slap could have enabled the graze mode in the May incident. Recall it was the last firing during the User Exploitation Trials where some 300 rounds were to be fired per a March report in this very thread. I don't know what was the barrel life per design and at what charge levels. Was it at highest charge? And were the firings using different charges for the shells. All this could have worn the barrel,

Side slap due to wear could have been the cause for this July incident. Why didn't the shell go off?

Singha I have seen no reports of the proximity fuze being used on these trials. Should be but no confirmation.

Rahul M · Post by **Rahul M** » 22 Jul 2017 20:58

chetak ji, IIRC OSA stays valid lifelong, it is the dept. specific acts that have a limited period valifity.

tsarkar · Post by **tsarkar** » 22 Jul 2017 21:08

srai wrote:
suryag wrote:What do you think will happen different with ATAGS? User exploitation trials followed by division exploitation trials followed by brigade exploitation trials and so on
If this happened to the imported ULH during exploitation phase (meaning contract already signed and deliveries have begun), would the IA have the authority to tell BAE to make changes and stop production before further can be inducted? Don't think so. They will have to induct all and work with the limitation. Down the road, they will need to pay for modifications.

For both Talwar and Vikramaditya, delivery was deferred until defects from trials were rectified. In the first case, financial penalties were levied and adjusted against next batch.

Suryag - did you read my earlier post on exploitation being common for every system inducted?