Sunday, 27 November 2011

Improving the Arjun's already great suspension





With Dr P Sivakumar, CVRDE's director, a formidable suspension systems specialist. Here's a brief on the Arjun Mark II's improved running gear...



by Ajai Shukla

One of the distinctive features of the Arjun tank is its hydro-pneumatic suspension, distinct from and far more advanced than the "torsion bar" arrangement that conventional MBTs (including the T-90) feature. The Arjun's suspension provides a smoother ride, making the tank a more stable gunnery platform that permits more accurate engagement of targets whilst on the move.

The Arjun Mark II features an enhanced version of the Arjun's well-proven hydro-pneumatic suspension, with the new one designed for a 70-tonne load. This is part of an improved "running gear", including the road wheel mountings, the road wheels, axle arms and shock absorbers.

The new suspension has already been tested in the recent trials and run for 1,300 kilometers. In order to obtain an accurate comparison with the earlier suspension, the trial tank was fitted with both: the old suspension on the left side and the new one on the right. The photographs --- in which the new suspension still looks new while the old suspension looks somewhat the worst for wear (not surprising; 1,300 km is a lot of running!) --- point to a successful upgrade.

The Arjun's suspension will be practically all-Indian. The road wheels, which continue to be built by Sundaram Industries, have been improved with better manufacturing and bonding processes for the rubber. Tractor Engineeers Ltd (TENGL), an L&T company, is doing parallel development of the Arjun track (imported so far), including development of one of the most difficult running gear technologies: the track pins.

I am amused at the many who appear to believe that the Arjun is "built entirely of foreign components" that are "hammered together in India". This kind of view is rooted in a deep lack of understanding of the processes of indigenisation. It is true that almost 60% of the cost of the Arjun goes on imported components. Practically all of that goes on just three components --- the power pack; the gunner's main sight (GMS); and the gun control equipment (GCE). Almost all the Arjun's other 10,000-odd component are sourced from Indian industry, which is rising to the challenge. More support from the government, in terms of better procurement procedures, would accelerate this.

There will be more on this particular issue in Broadsword. Stay tuned...

In ---

23 comments:

Nikhil said...

Excellent report and series Colonel Shukla. Please email these reports to DGMF officers and IA top brass. Can you also do a similar fact-finding series on the Bhisma and it's roadmap for ToT and import substitution, considering the large orders that it has bagged.

Anonymous said...

our dependence on foreign maal is deep rooted due to our colonial past!!! nice to see HAL calender in the office room of Mr. sivakumar!!!Good Luck!!!

Philip said...

I am a novice in the field but I see that several Arjun contemporaries have a skirt protecting the tracks. I see this lacking in Arjun. Is this an oversight ?

Broadsword said...

@ Nikhil

Reports on T-90S also coming up. Hold your peace...

@ Philip

It's called a skirting plate and the Arjun very much has it. I've posted an additional photo in which it is visible.

The skirting plate provides armour protection to the upper part of the running gear... including the top rollers on which the upper track runs. It cannot be extended further downwards for fear of it fouling with the ground in deep sand or slush.

Rahul said...

I am disappointed at the level of protection offered to wheels and most importantly SUSPENSION in MK-2 (considering the Graphic Image of MK-2 as final looking MK-2). DRDO should increase armour protecting by area so that much of suspension and if possible wheels gets covered.

Hari said...

Excellent article sir. I am still not sure why the IA is so skeptical about the Arjun. Is it just the fact that it is produced in India that is stopping them. Would love to hear your view point as to why IA was having reservations. And BTW nice laptop :)

DHRUV said...

this report seems to me as a new year gift,
Your style of writing binds the reader

Mr. Ra said...

With so many problems in the past, now Arjun has started showing the positive signs of development.

Anonymous said...

Please also mention some details on Bharat Power Pack, we do know that it wont be used on Arjun MKII, still if say the development is in final stages it might be introduced in the later 248 Arjun MkII which will roll out of Avadi from 2018 onwards as per Mr. sivakumar.

Anonymous said...

Wow Ajai, your forearms still reflect your army background, pushups going on eh?

Guru said...

Ajai,

Great article and a very detailed analysis of the Arjun.

One critical component development news that is so far absent from your reporting is the status of the development of the 1500HP indigenous engine by DRDO. The wiki article on the Arjun has this mentioned for the last 3 yrs but for some reason the DRDO link to it is now dead.

"http://en.wikipedia.org/wiki/Arjun_MBT#cite_note-27

A new 1500 hp engine is being developed that will eventually replace the present engine. An allocation of 40 crore (US$8.1 million) has been allocated for the project which is expected to be completed within five years"

What happened to this? Is this dead or has met the fate of the Kaveri?

I think the indigenous engine, if it comes alive would be a real boost to this programme.

Waiting for your response to this.

Rahul said...

Ajai Sir

Your logic regarding not extending skirting plates further downwards is reasonable and i also had similar idea(guess). But following pic says they are in use anyway. Since i am no expert (far from it) i can't comment on effects and consequences in relation with battle terrain. If i am not bothering you too much please throw some light.

http://dover.idf.il/NR/rdonlyres/30AF0C75-AB8D-4A74-88BC-4DD2210A797B/0/06s_cropped_big.jpg

http://upload.wikimedia.org/wikipedia/commons/f/fc/Challenger_II,_main_battle_tank_prepares_to_fire_its_main_gun_on_a_target.JPG

arun said...

most of the comments attacking india, drdo and on indigenization come from pakistanis who are adept at using indian names, and attacking indian programs and projects. this is common on the internet and on blogs. the average indian is proud of what his nation has achieved, its only the amazing number of insecure trolls from across the border who think otherwise, bar a few souls who sitting in their air conditioned cabins, doing basic IT jobs think that gives them knowledge of engineering. all said and done, expect more attacks on you and your blog, and on drdo/india because you are doing such an amazing public service and shows how far ahead india is.

G.one said...

Sir! why Indian army asking to reduce the weight of Arjun although the most most of MTB around the world have weight aprox 60 to 65 ton and they also face almost same condition in field like Indian condition ? even leopard, challenger, abrams , merkava have same weight as of Arjun..

Anonymous said...

It is worrisome to see the person in such critical post using windows. I hope he doesn't store anything confidential on that particular system.
Full marks to you though :)

Nayan said...

Hi Ajay,

A very nice article. You have an amazing power to convince your readers! No, that's a complement.

May I answer Hari's question..“I am still not sure why the IA is so skeptical about the Arjun”. The word “sceptical” used by Hari is the least offensive. I have heard People using the word “unpatriotic” for not accepting an indigenous product and that was very painful. Here are my feelings and am not a Pakistani haha hehe.

The IA has fought all its war since independence with inferior equipment in comparison to its adversary. Tell me it’s a fact or not? If our soldiers won the battle at the end of the day it was inspite of government's efforts to let them down all along the way!

The frustration of the IA comes from one singular fact. The DRDO has always over promised and under delivered. There is no exception to this statement. They have directly come in the way of modernisation of the IA. If you were to analyse why the IA is ill equipped even today to survive in the modern day battlefield, it is the DRDO. They were not able to solve the problem as they were part of the problem. They have not been held accountable for sinking billion of dollars into the rabbit hole. If DRDO were to function with corporate efficiency the IA would have been in a different level.

On a different note may I also express my views on Arjun's suspension. The hydro pneumatic suspension of the Arjun MBT is both a bane as well as a boon The main advantages of a torsion bar suspension are durability, easy adjustability of ride height, and small profile along the width of the vehicle. It takes up less of the vehicle's interior volume. And what is more it is easiest to maintain and its MTBF is very high.

Compare this with much touted hydro pneumatic suspension. It requires a specifically trained mechanic, Hydro-pneumatic suspension systems can be expensive to repair or replace. Failure of the hydraulic system will cause braking power to decrease as the accumulator is the same and can result in a catastrophe. It will make the tank that much vulnerable. A fluid valve leaks, jams or malfunctions and you are a sitting duck! Sometimes more sophistication does not get translated to more success.

Anonymous said...

Thanks a lot Ajai sir. Now pls post some updates on IAC carrier, PDV missile and P-15A destroyer. Thanks. :) Lookin forward to you.

Anonymous said...

Liked these words sir...

"I am amused at the many who appear to believe that the Arjun is "built entirely of foreign components" that are "hammered together in India". This kind of view is rooted in a deep lack of understanding of the processes of indigenisation. It is true that almost 60% of the cost of the Arjun goes on imported components. Practically all of that goes on just three components --- the power pack; the gunner's main sight (GMS); and the gun control equipment (GCE). Almost all the Arjun's other 10,000-odd component are sourced from Indian industry, which is rising to the challenge. More support from the government, in terms of better procurement procedures, would accelerate this."

Anonymous said...

So we are going to use indigenous engine?. Also why not order 1000 arjun mk2 which will bring down the cost too?.Please can you explain it to us?

Anonymous said...

Nayan, Usually it's the Pakistanis who make wild accusations. Now advantages and disadvantages of Hydro pneumatic suspension from Wikipedia.
http://en.wikipedia.org/wiki/Hydropneumatic_suspension#Advantages

jj said...

Nice series of articles. Was hoping to see something on the gun and armour too.

Anonymous said...

Ajai Sir, you have some great photos of the T-90 assembly line showing incomplete tanks and including hull without the turret installed.

http://1.bp.blogspot.com/-eUYEa4syp9k/TtOQcF1fFiI/AAAAAAAACCY/vDSV1qvzJRw/s1600/T-90%2Bline2.jpg

http://2.bp.blogspot.com/-4NQKLIuN9iU/TtOQMrXazCI/AAAAAAAACCM/Gxqsh4HCKmk/s1600/T-90%2Bline1.jpg

But why no such pictures of our Arjun? :(
Were you not given access to the assembly line and did they bar you from taking photos of the Arjun's assembly line?

Please more photos of the Arjun's assembly line. You can also have another article based on photo description on how our Arjun is produced. It would be simply awesome.
Please more photos of Arjun MK1 & MK2.

Anonymous said...

Hi there Ajai,
The blog post at trishul-trident.blogpost.com have a completely different version to yours on their story about Arjun MBT MkII. They say that MkII will: "have a higher imported content than its predecessor". Have a read and see if you can negate their claims.

Thank you,
Aj