Artillery: News & Discussion

ramana · Post by **ramana** » 25 Feb 2018 22:30

Prasad, It's posted already. No worries.

RKumar · Post by **RKumar** » 26 Feb 2018 00:26

IA should open new front for napaki army. PA should not choose places to escalate. South Cashmir is perfect place to start artillery fire and test our new guns

Gagan · Post by **Gagan** » 26 Feb 2018 01:41

Yaa,
Test all the Nag, Helina, Guruthma versions on the Packee posts, best form of field trials

Singha · Post by **Singha** » 26 Feb 2018 13:44

this leaked report from MOD on the procurement mess quantifies the vast delays and mess that it is
https://www.ndtv.com/india-news/defence ... -topscroll

with procurement a mess, the only way forward is internal development

srai · Post by **srai** » 26 Feb 2018 18:37

Gagan wrote:Yaa,
Test all the Nag, Helina, Guruthma versions on the Packee posts, best form of field trials

Then can be exported with slogan “proven in combat” like other exporting nations do.

Gagan · Post by **Gagan** » 27 Feb 2018 00:10

I shouldn’t give the Army Leadership any ideas, but they could include yet another hoop to make the indiginous defence products jump through to delay procument - Live Combat Field Trials

Live Combat Field Trials, tests a weapon systems effectiveness in field conditions that very closely resemble actual warlike situation and is meant to provide a most realistic assessment of a weapon system’s suitability for field deployment. The trial is also meant to provide hands on training to the Jawans who are expected to be end users and to obtain feedback

Feedback from the target area or the targetee is not mandatory, but may be obtained if so desired by the manufacturer

However feedback in the form of audio-visual recordings of the use will be gathered. This may be disseminated for wider viewing at the discretion of the ministry of defence

Weapon systems qualifying in such trials will be designated “Combat Proven” and will be given a total of 02 points towards the overall assessment score

Gagan · Post by **Gagan** » 27 Feb 2018 00:15

Why can’t DDM send some reporters across the LOC to talk to the Paki Jawans and ask stoopid questions like “Aapko kaisa lag raha hai, aapki post bharatiya anti tank missile se tabah kar di gayi.”
“Kya mehsoos kar rahe hain is waqt?”

ramana · Post by **ramana** » 27 Feb 2018 04:24

Last week I had some time to spare and spent a lot of midnight oil trying to read up on shell balloting phenomenon. Its not like only OFB shells and India Army guns have this problem. Except since we don't understand it we whine to half baked reporters.
Many of the reports I read are quite mathematical but I will keep it qualitative and at high level to make the points. I will refer to reports available online to make the points for further reading.

Background:

Over past five years Indian press has reported numerous instance of 155mm shell burst and muzzle strikes in barrels. Many of these are documented in this thread on earlier pages and can be searched for details. Number of occurrences per press reports is Bofors (40 times), upgraded M-46 130mm guns, Dhanush (3 times), and now M777 (1 time).These incidents have happened in Bofors 39 calibers, Soltam 45 caliber, Dhanush 45 caliber and M777 BAE guns. And have happened with imported NASCHEM and OFB made shells. The only data we have is the shells have burst after many rounds have been fired. We know for the M777 incidents the shells were ERFB/BB and BT units. We don't know about the other shells as the sources were not forthcoming. However in most likelihood it could be the ERFB types of shell as the IA wants maximum range for the artillery.

Discussion:

Shell burst in barrel and muzzle strike are all phenomenon related to internal ballistics of the gun. They relate to interaction of shell and gun barrel after the charge is ignited. We can ignore all other types of ballistics as not being germane to this topic.

Lets talk about the barrel. The barrel is designated as 155mm x 39, 155mmx45 from breech end to muzzle exit. This means the barrel is 39 x 155 equals 6045mm and 45x 155 equals 6975 mm. The muzzle is not rifled.

The barrel can be considered as a long thick wall pressure vessel and has a muzzle brake at one end to reduce forces of recoil. After the charge ignition, the barrel develops circumferential tensile stresses (hoop stress) which are prominent. Hence the barrels are made of high strength steel and are heat treated and a compressive pre-stress by auto-frettage to overcome the high tensile stresses. There could be micro cracks developed in the manufacturing process and occasional high charge ignition. Repeated firings induce fatigue and could cause barrel to fail. Part of development testing is to find the fatigue life and change barrels before barrel failure.

Another phenomenon is barrel wear. The shell is a tight fit in the barrel at the driving band and the bourrelet. The charge ignition causes the shell to move forward and the rifling of the barrel imparts spin to the shell. Usually the rifling is 1 in 20 for the 155mm gun. That means the rifling twist is 1 in 20*155mm i.e. 3100 mm. This means the shell makes one revolution in a travel of 3100 mm.
(note the barrel length including muzzle is about 6045mm. In other words the shell hardly makes less than 2 turns inside the barrel!)This causes friction wear. In addition due to the high temperature gases and chemical compounds in the shell propellant there is erosion wear. Studies have shown the erosion wear is higher than the friction wear as the shell driving band is made of copper or other softer metal than the steel used for the barrel. Part of development testing is to find out the barrel wear life and determine when the barrels need to be changed. Gun barrel wear is measured after numerous firings and the population divided into four quartile. 1st quartile would be like zero to little wear and 4th quartile would be maximum wear and near to replacement.

Comparing the barrel fatigue life to the barrel erosion life the latter is found to be more predominant for determining gun barrel life. In other words a barrel will wear out before It burst unless there is an accident.

Lets talk about the shell. The shell at macro level is a long cylinder with an ogive nose for aerodynamic shape. In order to resist the firing pressure the base of the shell is thicker and hence the cg is closer to the base. The center of pressure is forward of the cg and will lead to static instability, like a top will rest on its side when not spinning.

The ogive portion has the fuze cavity and houses the fuze. Early 155mm shells like the M107 were made from low carbon steel and were stubbier. The search for longer range and for fragmentation effects led to developing the ERFB/BB shells which are long and made from manganese steel which can fragment easily. Then to sum up these two type of shells are shaped differently and made from different materials but both are fired from same gun barrel with constant 1 in 20 rifling which imparts same spin. The charge determines how quickly the shell gets spun. Now both shells are manufactured by forging from steel blanks and are machined on lathes, driving band shrunk fit and explosives filled. This process ensures the shells are quite defect free as the forging process subjects them to large forces and machining ensures they are concentric. However there could be manufacturing tolerances that are inherent in the process. The driving band could be installed slightly closer to the base or farther from the base. The center of gravity could be offset from the axis of the shell and at an angle due to manufacturing and assembly.

Analysis:

Earlier I had proposed looking at the shell as a spinning top from our childhood. Usually there are short and squat tops (SQT) or long, thin tops (LTT). A SQT needs less spin and is more stable in the sense it wont be disturbed when it gets a side load. The LTT needs more spin and is less stable as it gets disturbed easily when it gets a side load. And both tops spin true when they are axisymmetric. If you recall there is a brass nail that's driven into the top of the wooden top to give more mass to the large end. This makes it more balanced and stable during spinning. When the top is slowing down the cg point moves in a rosette pattern called nutation. This shows up as wobble. Balloting is the shell wobble in the gun barrel.

During World War I it was noticed that shells when they emerge from the barrel would hit it at exit and sometimes catastrophically. This was called 'side slap'. Not much was understood. During WWII, British mathematicians studied this and described the forces due to slide slap could be around 20,000 gs and sometime break off the fuze while the shell still travels as a dud to its full range. After WWII, US army started studying this phenomenon and produced numerous papers. During Vietnam war it was noted that 175mm barrels were bursting way before their 4th Quartile life. Analysis showed that due to cg offset (only 0.1") and barrel wear the shell was hitting the barrel sides and exploding in it. During the recent decades the phenomenon was called balloting and more studies have been undertaken as the shell fuzes are upgraded to electronic components which are fragile. Now with PGK fuzes there is a need to study the forces and not have failures.

Of these one relevant study for our purposes is "Characterization of the Parameters That Affect Projectile Balloting using FEA" Phd Thesis by Kelly Laughlin in 2008 (Ref 2). Laughlin modeled the 155mm barrel and shell and calibrated it to test data prior to changing different parameters that affect balloting. He looked at barrel wear by running two models to represent 1st and 4th quartile and at zero and 70 degree elevation. Next he varied the location of the driving band with respect to the base of the shell. He also moved the CG axially forward and aft of its theoretical location and offset it from the shell axis by a set number. He also varied the distance between the rear and forward bourrelet (wheel base), and finally the total shell length within the drawing tolerances.

The barrel 1st and 4th quartile and the two elevations did not produce any differences in axial accelerations. The higher elevation had slightly less balloting but both had some degree of balloting and prominent as shell moves closer to the muzzle exit. As the CG moves forward, balloting at muzzle exit increases to almost double of the nominal case. As CG moves closer to base it reduces the balloting effect. The wheel base (distance between the bourrelets) variation effect of the balloting is similar to the CG variation as it increases with increase from the base and decreases with reducing the distance. The driving band location is also similar to the CG and wheel base variation. He found that installing the driving band towards the base reduces balloting. The body length variation is similar in that a short body has reduced balloting while a longer body has more balloting (ERFB note is long body)

The most interesting thing happens when the CG is offset at a distance (0.148") from the shell axis. The balloting frequency is higher than all other variations and very high magnitude of up to 5,000gs and up. This trend is same for all four gun tube variations. i.e. 1st and 4th quartile and zero and 70 degree.

Analysis Discussion.

Analysis shows that CG offset from centerline causes extreme radial accelerations due to the unbalance nature of the shell even in nominal barrels. The magnitudes show it could result in muzzle strike while emerging from the barrel.

We know from various reports that Dhanush development trials had barrel burst due to shell wobble.
And this gun fired 3000 rounds before the barrel burst.

The Dhanush prototype suffered a barrel burst during firing trials at Pokhran in August last year, which has since been resolved.

An official with knowledge of the matter said. “It's true that the trial at Pokhran didn't go well. There was a barrel burst. However, it was later confirmed that the burst was not due to a defective barrel, rather the ammunition wobbled out-of-axis to exert additional pressure on the barrel, causing the accident”.

The M777 gun had a shell break up at the 1164th round

viewtopic.php?p=2230473#p2230473

I don't know the barrel life for these at max charge. I suspect its close to 1100 rounds.

On page 57, the forward shift from the base of the CG gives 5K gs for even nominal barrel.
Further on page 115, 4th quartile with CG offset shows the large radial accelerations at muzzle exit.

IA Board of Inquiry should look at barrel dimensions as part of the investigation.

Most likely firing the guns at max charge quickly puts them in the 4th quartile.

It would definitely show the muzzle strike severity.

Conclusion:

Muzzle strike happens with CG offset. And will worsen with barrel wear.
Most of the IA field trials having barrel burst are likely after barrel wear which makes even small CG offset into a big problem.

Also IA should consider going to eight gun batteries is they desire a high volume of fire and not subject the guns to beyond normal usage which causes barrel wear that in turn magnifies any shell imbalances even within tolerance.

Reference:

1) Hindu : Dinaker Peri No Dhanush for Army

2) https://en.wikipedia.org/wiki/M107_self-propelled_gun

3) Characterization of the Parameters that Affect Projectile Balloting using Finite Element Analysis: PhD thesis

ashish raval · Post by **ashish raval** » 27 Feb 2018 05:08

Singha wrote:this leaked report from MOD on the procurement mess quantifies the vast delays and mess that it is
https://www.ndtv.com/india-news/defence ... -topscroll

with procurement a mess, the only way forward is internal development

We should have started at least 15 years back on these and if this had happened, we would have been producing state of the art by now (not that current ones are inferior but they would have been thoroughly tested and enhanced).
First batch of objects are always of inferior quality and any and every major weapons producing nation will tell you that. It takes few decades to master complex weapons systems development and our armed forces really wants Mercedes from Day 1 while we are just designing Maruti's.

I must say that forces will have their limit on how much they can wait and get away with slightly less capable weapons. We have lost too much time.

DO NOT RELY ON ANY FOREIGN FIRMS TO INVEST and GIVE AWAY THEIR GOOSE LAYING GOLDEN EGGS, JUST PASS TECHNOLOGY TO DESI PRIVATE PLAYERS WITH CLAUSES and THEY SHALL DO THE REST IN ONE DECADE.

JTull · Post by **JTull** » 27 Feb 2018 18:48

DRDO 155/52 mm ATAGS howitzers in high altitude trials in Sikkim, Jan 2018.

Bharat Forge’s G-2 prototype (L), Tata Power SED’s G-1 (R).

JTull · Post by **JTull** » 27 Feb 2018 19:01

INDIA TODAY: Bang for the buck?

A key indigenous breakthrough-a sophisticated high-strength barrel made by Bharat Forge using autofrettage technology-is used in both prototypes.

Manish_P · Post by **Manish_P** » 28 Feb 2018 12:49

^^ A lovely photo.Thanks for sharing!

Akshay Kapoor · Post by **Akshay Kapoor** » 01 Mar 2018 19:27

sum wrote:Shatrujeet reporting 155mm pounding pak positions in last couple of days and the first 155mm firing since 2003.

Good news if correct. I was under the impression only 105 mm were used and that too sparingly.

Akshay Kapoor · Post by **Akshay Kapoor** » 01 Mar 2018 19:36

ramana wrote:Ever since Babur at Panipat, artillery has been a weakness for Indians. In fact Brirish Indian Army was allowed to raise artillery formations only just before WWII.

After initial 75mm pack and 105mm howitzer, IA has ensured no Indian development of artillery with their attitude. You can't innovate what you don't design and make.

US adopted the French 75, 105 and 155mm during world war I and continusouky developed them. Even now US is learning the 155mm intricacies. The advent of electronic fuzes has made tube ballistics were important to learn.

It's sad the IA wants to keep importing.

I think the COI are a farce for they resume trials and things fall apart. They don't know what they dont know.
One simple table listing all the shell and gun failures will.show a pattern.
Date, Type of gun, calibers, shell, Fuze, charge, barrel diameter, how many rounds already fired from that gun, Comments.
They can't do even this simple table and have jokers talking to media with humanities background.

Ramana,

I am very surprised at your comment. What is this bs 'humanities background'. I am leaving this comment here to show how even seasoned posters and moderators have a severe attitude problem and superiority complex. I suggest you review your post and edit it or I will do so.

I was away for sometime and I see that this thread has started its degeneration. I am back now and no more of this nonsense.

ramana · Post by **ramana** » 02 Mar 2018 00:39

The media with humanities background.

kit · Post by **kit** » 02 Mar 2018 00:57

sum wrote:Shatrujeet reporting 155mm pounding pak positions in last couple of days and the first 155mm firing since 2003.

wonder if there are air burst FAE rounds for 155 guns

.. would be interesting to see what a 100 155mm guns firing simultaneously FAE rounds can do to the paki border

sohamn · Post by **sohamn** » 02 Mar 2018 02:29

ramana wrote:The media with humanities background.

I think what Ramana might have meant is that defence media in India are mainly obsessed with language skills instead of defence tech skills. i.e. lack of relevant experience. Not that humanities is a bad profession for journalists but it might not be the most suitable background for defence journos.

But I will let him clarify.

Philip · Post by **Philip** » 02 Mar 2018 03:33

The IA which has been starved for arty for so long should support these desi efforts which have such great potential, record beaters too, so that they can be inducted asap even in initial MK-1 batches so that the production flow can be established with key improvements made in later batches.This would also come in at lower costs.Key factor though is the ammo production, as our DPSUs, OFB in particular have produced faulty duds in the past wasting thousands of crores.

ramana · Post by **ramana** » 02 Mar 2018 05:17

Philip read my post above. Its the system.

ramana · Post by **ramana** » 02 Mar 2018 05:30

Krasnopol M is with Indian Army.

https://twitter.com/reachanshul/status/ ... 97857?s=19

Apparently costs Rs. 15 lakhs per round.

Look at Chinese GP1. Doesnt look like that costly.

ramana · Post by **ramana** » 02 Mar 2018 07:12

Chinese GP-1 LDR based on Krasnopol

http://armamentresearch.com/chinese-gp1 ... -in-libya/

ramana · Post by **ramana** » 02 Mar 2018 22:24

I found an internet reference to the M-77 barrel requirements.

The objective is 800 firings and the threshold is 900 firings.

The IA user trials had the ERFB round break up at 1164th round.
In other words 364 rounds over the objective and 264 rounds over the threshold for the M 777 barrel.

Make up your own mind.

Neilz · Post by **Neilz** » 02 Mar 2018 23:20

#ATAGS in action. Desert, mountain. #MakeInIndia.

https://twitter.com/SandeepUnnithan/sta ... twterm%5E3

Shameek · Post by **Shameek** » 03 Mar 2018 02:25

The BB round from Pokhran looks like a rocket launch! The Sikkim round seems to have very little recoil. Looks promising!

brar_w · Post by **brar_w** » 03 Mar 2018 02:38

ramana wrote:I found an internet reference to the M-77 barrel requirements.

The objective is 800 firings and the threshold is 900 firings.

The IA user trials had the ERFB round break up at 1164th round.
In other words 364 rounds over the objective and 264 rounds over the threshold for the M 777 barrel.

Make up your own mind.

Objective would be 900 and threshold 800 i.e. the min. they would be able to accept but that would be for system aborts.

3.2.5.3.1 Cannon Tube Fatigue Life The cannon tube shall have a
fatigue life of at least 2,650 equivalent full charge (EFC)
rounds, based on firing M549A1 or M864 projectiles with M203A1
propelling charge. The cannon fatigue life shall exceed the wear
life. - https://fas.org/man/dod-101/sys/land/do ... 5-spec.pdf

ramana · Post by **ramana** » 03 Mar 2018 04:42

So there was no wear life specified?
Only that fatigue life should exceed wear life.

Where could I have seen it?

Some articles on M777 barrels

M777 Artillery

Chrome plating barrel increase wear life

OK here is a number when firing high charge.

Sustained Fire At Extreme Range In Syria

....
A Marine Corps battery (six guns) of M777 155mm howitzers was sent to Syria in early 2017 to support the SDF Kurdish militia as it advanced towards and took the ISIL (Islamic State in Iraq and the Levant) capital of Raqqa. The marines fired mostly M1156 GPS guided shells and did so at extreme ranges. In doing so they wore out the barrels on two of their howitzers. Normally the M777 barrel can fire up to 2,500 shells before wearing out but barrel life depends on what type of shell your fire. If you fire the longer range shells (which the marines did) barrel life is much reduced (to about a thousand rounds). ....

So at high charge they wear out at around 1000 rounds..

I will still look for the 800/900 O/T numbers.

Philip · Post by **Philip** » 03 Mar 2018 05:15

Answer to problem.More guns with lesser firing rates and rounds, spread the load.This does then require more guns! Chicken and egg situ.

ramana · Post by **ramana** » 03 Mar 2018 06:00

They used to have 8 gun batteries.
This chrome plating the barrels adds costs and fouls up the barrels.

But adding two more adds people to the Arty regiments.

ramana · Post by **ramana** » 03 Mar 2018 07:25

Got it.

Link:

https://www.globalsecurity.org/military ... /lw155.htm

The LW155 Mean Rounds Between System Abort (MRBSA) shall be no less than 800 rounds (threshold) to 900 rounds (objective), to be demonstrated with an 80% confidence, when employed IAW with the LW155 Design Reference Mission Profile.

I might have not understood this MRBSA.

brar_w · Post by **brar_w** » 03 Mar 2018 07:40

This was what I was saying. The info on MRBSA is in the requirements document i shared earlier. Often, not all the the specific requirements are explicitly stated in the scrubbed/unclassified version of these documents.

pravula · Post by **pravula** » 03 Mar 2018 08:23

ramana wrote:Got it.

Link:

https://www.globalsecurity.org/military ... /lw155.htm

The LW155 Mean Rounds Between System Abort (MRBSA) shall be no less than 800 rounds (threshold) to 900 rounds (objective), to be demonstrated with an 80% confidence, when employed IAW with the LW155 Design Reference Mission Profile.
I might have not understood this MRBSA.

Do note the 80% confidence.

brar_w · Post by **brar_w** » 03 Mar 2018 08:30

pravula wrote:
Do note the 80% confidence.

This is taking a weapon system with a specified requirement for reliability and seeking that it be demonstrated via finite testing, hence this 80% confidence value has become the standard when it comes to systems where reliability drives mission effectiveness and Operational cost over life-time. Some background. Requirements are created for a particular reason and they must specify what needs to be demonstrated during developmental, and operational testing.

Most system performance requirements can be
demonstrated with high confidence through testing (such as
weight or speed). However, since reliability is a probabilistic
value it cannot be demonstrated by a simple (or short) test.
We must resort to accepting some level of “confidence” that
the requirement will be achieved based on limited testing. In a
simplistic sense, this confidence is a function of the required
reliability value, the number of failures experienced during the
test, and test duration. While we know the requirement (from
the system specification) and we can plan for realistic test
duration, the number of failures experienced is a function of
the “true” reliability of the system and, to some degree,
random chance. In other words, we could be “lucky” and
experience fewer failures during a test than the “true”
reliability would predict or we could be “unlucky” and
experience more failures than we would expect.
Fundamentally, the longer the test duration, the less likely the
results will be influenced by luck, but there are practical
limitations on the test time. Since our test duration cannot be
infinite, we are resigned to accepting some level of confidence
less than 100%. A confidence value of 80% is generally
accepted for demonstration of reliability requirements. The
challenge is to demonstrate a reliability objective with 80%
confidence. This often requires extending the test to allow
collection of sufficient data to achieve confidence in the
results.

The other major contributor to the required test duration
(besides desired confidence levels) is the “true” or inherent
system reliability. The more the true value exceeds the
required value, the less test time is needed to provide 80%
confidence. This leads to establishing a “goal” or “design to”
target reliability that may be as much as 50% to 100% greater
than the required value in some cases. While it may seem like
the best approach to reduce the risk of not demonstrating
compliance with 80% confidence is to design above the
requirement, in reality designing and producing a system that
exceeds the required value adds significant development and
production cost.

ramana · Post by **ramana** » 04 Mar 2018 09:28

I am looking for accounts and books on artillery usage in 1965 and 1971 war.

And would like to know the rationale for Gen.Sunderji deciding to standardize on 155mm guns in mid 1980s.

nam · Post by **nam** » 05 Mar 2018 15:25

Tata version of ATAGS. Very TFTA.

https://twitter.com/IndiaToday/status/9 ... 3196529664

JTull · Post by **JTull** » 05 Mar 2018 22:12

US blames Indian ammo for gun snag, test today

INDIAN AND US officials will jointly test the American-made M777 ultra-light howitzer Monday after its muzzle broke during tests at a firing range in Pokharan six months ago, The Indian Express has learnt.

The tests will be conducted in Pokharan by a joint investigation committee (JIC) comprising US and Indian officials. US officials have blamed the accident on ammunition indigenously manufactured by the Ordnance Factories Board (OFB) — the Indian side has denied the charge.

India signed a deal in November 2016 with the US to procure 145 M777 ultra-light howitzers for deployment on mountainous terrain in the northern and eastern borders. It was the first such induction of artillery guns since the Swedish Bofors guns in the late-1980s, which got embroiled in political controversy. As part of the Rs 5,070-crore deal, with delivery to be completed by 2021, two M777 guns were brought to India last May for field firing with Indian ammunition to compile “firing tables” that provide data such as range and elevation.

The accident, on September 2, 2017, involved one of these two guns when a projectile, the fifth in a series, exited in multiple pieces, damaging the barrel and breaking the muzzle.

The JIC, including OFB and Army officials, and representatives of the US Defence department and BAE Systems, the manufacturer, was formed to investigate the causes. But the two sides could not agree on the reasons in five meetings of the JIC held so far. The US officials claimed that the ammunition did not have explosive of the right consistency, which was denied by Indian officials.

The sixth meeting of JIC will be held on Tuesday and Wednesday, after “instrumented firing” with specialised equipment from the US to check the differential pressure in the barrel while firing Indian ammunition.

Speaking to The Indian Express, official sources said, “All the team members will freely and frankly share their point of view during the JIC meeting. We will know more about the cause of the accident after the data from instrumented firing is analysed and presented to us.”

If the JIT reaches a conclusion this week, further testing to complete the firing table would be scheduled. According to the earlier schedule, the table was to be compiled by the end of September.

Official sources, however, were not willing to speak about whether the accident would lead to a delay in induction of the M777 howitzer guns.

Under the contract, 25 M777 guns will be inducted directly with the rest to be assembled at the BAE Systems facility in Maharashtra in partnership with Mahindra Group.

I wish this order gets cancelled or gets accused of corruption by Pappu. Like Tejas, only then Dhanush and ATAGS order will come.

ramana · Post by **ramana** » 05 Mar 2018 22:27

JTull I don't think so. For IA does need these guns in the mountain regions.

This gun is different and is for MSC. Dhanush and ATAGS are for the plains.
So both are needed.

The instrumented shell they talk about is the instrumented fuze that measures radial and longitudinal accelerations and transmits with patch antennas. Read the PhD thesis I had linked before. It describes this gadget.

This technology DRDO can benefit from also. I hope some off the best scientists are put in this JIC and not just the OFB types.
Its a science problem not a mfg problem.

M777 had barrel burst earlier so they must have done root cause on those incidents.

The US charge that

The US officials claimed that the ammunition did not have explosive of the right consistency, which was denied by Indian officials.

Means they say the explosive had lumps in it that cause a CG offset when it solidifies.
Plausible but not probable as 1164 shells were fired from the gun that suffered from the shell break up.
If CG offset was there as a systemic issue it would have shown up or manifested earlier.

The phrase "Shell exited muzzle in pieces' is a result and the cause is shell break up.
Wish the briefing and press reports accurately.

ramana · Post by **ramana** » 05 Mar 2018 22:39

Love those comments in that article.. As ill informed as can be.

I had said many times the Panchatantra folk tale "Brahmin and the Tiger' is quintessential Indian tale. These comments are similar to the first two witn(l)ess statements in that folks talk from the tree and the buffalo. Have nothing to do with the situation at hand.

ArjunPandit · Post by **ArjunPandit** » 05 Mar 2018 23:05

ramana wrote:Love those comments in that article.. As ill informed as can be.

I had said many times the Panchatantra folk tale "Brahmin and the Tiger' is quintessential Indian tale. These comments are similar to the first two witn(l)ess statements in that folks talk from the tree and the buffalo. Have nothing to do with the situation at hand.

I wonder if these are indians or chinese 10centers or paki 1 roti/boti guys

ramana · Post by **ramana** » 05 Mar 2018 23:11

No RNI= Resident Non Indians. But do read or watch the folk tale especially Ben Kingsley narration on Youtube.

ramana · Post by **ramana** » 06 Mar 2018 07:40

Vidur,

The shell balloting thesis I linked above in its conclusions says

It is evident that the CG radial offset variation is the most significant
contributor to balloting. This is followed by the CG axial variation and the
projectile body variation, followed by the wheel base length and lastly the band
location.

So all these are shell based parameters and OFB should look at their mfg processes and do a statistical measurement of these parameters.
The CG offset variation gets magnified in worn gun tubes.

I think you should have OFB look into these as a safety issue as servicemen are injured by this.