Arjun Main Battle Tank (MBT)

[Dejawolf]

I need not understand any dejawolf work,

In fact I corrected his faulty works to reflect the true picture like above,

for which he has no answers, So I assume he accepted it.




So the distance between the yellow and green line is 800 mm.

And that is the thickness of the only one armour block after FCS (main sight) in Arjun Mk.I

and what exactly did you base this baseless "correction" on?
it doesn't compare with any pictures i've seen of the arjun.
also, how can you make measurements off of this? i thought you said it was completely dimensionless.....

 

[ersakthivel]

and what exactly did you base this baseless "correction" on?

There in the picture above and if you can't understand read the last 40 pages.

http://upload.wikimedia.org/wikipedia/commons/6/61/HeadAnthropometry.JPG

As per the above head measurement table the height from chin to head top for 50 percent of humans is 23 mm.

in the picture-2 above the ratio for the height of the Tc's head divided by the head rest height is about 2.

So 23/2= 115mm is the height of the head rest.

In the picture 1 above the ratio of the width of the photo(the distance between the Tc seat head rest and the roof top vision block opening ) divided by the height of the head rest is 10.

[project the Tc seat headrest to photo's right side edge to get the ratio at the photo's edge.
In my screen the photo width is 20 cm

and the projected headrest's height at the photo's right side edge is 2 cm, So the ratio is 10.]

So 10 x 115 mm is 1150 mm.

So the the distance between the Tc seat head rest and the roof top vision block opening is 1150 mm ,
Correct? or not?

 

[Dejawolf]

There in the picture above and if you can't understand read the last 40 pages.

that's not enough, and you can read the last 300 pages to see why you are wrong.

 

[ersakthivel]

that's not enough, and you can read the last 300 pages to see why you are wrong.

See the above post no 5524

The rough draw may not be upto scale, it is a rough and ready alteration of what militarista posted to communicate my point of view.

1. A ----------the distance between gun mantlet plate front tip and the back edge of the main sight cutaway= 700mm according to your previous posts.

2. B ----------- The distance between the back edge of the main sight cutaway and the opening for roof top vision block inside Arjun turret (the back edge of the main gunner's sight block is in vertical line with roof top vision block opening inside Arjun turret) = 800 mm(LOS for composite armor)


3. C ---------- the distance between the back edge of the main gunner's sight block and the gunner's seat back head rest=500 mm.

4. D ------------the distance between the gunner's seat back head rest and the vertical standing crew hatch cover in the line drawing posted below = 500mm. gunner's seat back head rest is in vertical straight line with the front arc edge of the round crew hole.

So A + B + C + D = 700 + 800 + 500 + 500 = 2500 mm.


1.The red rectangle marked measurement A starts at the gun mantlet plate tip and ends at the main sight cutaway back side edge.

2. The blue rectangle signifying B starts at the where A ends and stops at back edge of the gunner's main sight bloc back edge.


3. The yellow rectangle C starts at the point where B ends and stops at the back side of the gunner's seat headrest's back edge.


4.The green rectangle D starts at where C ends and stops at the swivel or the base of the vertical standing crew hatch cover base in the only line drawing dimensions posted in this post above.


1. the length of A-------The red rectangle's length is 700 mm.

2.The length of B-------The red rectangle's length is 800 mm.

3.The length of C-------The red rectangle's length is 500 mm.

4.The length of D-------The red rectangle's length is 500 mm.

A + B + C + D =2500 mm.

The end of the green rectangle D is exactly at 2500 mm from the front tip of the gun mantle plate according to the drawing with dimensions from where you supposedly took you measurements for your 3D model.

The following photo validates my measurement of the length of the green (D) and yellow(C) rectangle.

1.The Tc seat edge the ending point of the yellow rectangle is situated at 2500 mm behind the gun mantle plate tip according to the line drawing with scale measurements.

2.The gunner's seat , the ending point of the yellow rectangle is locate at at 2000 mm from gun mantle plate tip according to the line drawing with scale measurements.

3.Since the Tc himself has just 500 mm seat breadth the gunner too will have the same 500 mm. So the ending point of the blue rectangle is at 1500 mm from gun mantle plate tip according to the line drawing with scale measurements.

And the photo above is a clear proof that the roof top vision block brings light into the Arjun turret in a slanting rectangular channel at the point of the end of the blue rectangle i.e a point in vertical line with the back side of the gunner's main vision block with binocular like eye pieces.

4.Also since the main sight cutaway stops at 700 mm from the gun mantle plate tip ,

according to the line drawing with scale measurements the ending point of the red rectangle , is locates at 700 from the gun mantle plate tip according to the line drawing with scale measurements.


So 1500 mm- 700 mm =800 mm is the LOS armor thickness behind the main sight without any doubt.

And the roof top vision block brings light to the gunner's main vision block through a slating rectangular channel.

If the main sight is pushed up like the latest model LEOs the Arjun can have 300 mm more LOS behind the main sight than any LEO model, because it's turret is longer and lower than LEO.

So any 380 mm LOS or 300 mm LOS behind the main sight is pointless according to the photo proofs
So all the four consistent continuous measurement marking arrow lines will give you undeniable evidence of very strong protection behind Arjun main sight back side contrary to your views based on faulty 3 D model is my opinion based on the line drawing and the photographs in this page,

But I have never seen the Arjun tank . So I don't claim it is the concrete truth from my first hand experience of arjun. but the measurement leaves no doubt , especially Arjun turret is not only shorter and wider , but longer than Leo- 2 as well. it is this small crucial detail you omit

 

[Damian]

We do not need to waste our time and our health on to endless debate

Kunal Biswas talked with one of engineers, engineer more or less confirmed at least one feature of Arjun Mk1 turret that we were capable to observe and point out, which preaty much means our observations are correct

What is more important, me and Militarysta preaty much presented the results to tank enthusiasts community, and as far as I know, most of them (if not all), that have good knowledge and understanding of tank designing, agrees with these conclusions.

 

[militarysta]

more od less truth is here:





And this what Kunal posted is very important and really consist whit above estimatous. There is no composite Armour behind FCS[. Answer is simple - LOS after main sight is so small (thin) that there was no point to put there multilayer armour - becouse LOS is small nececcery was to put there something what shoud achive as big as it's possible protection in relation to thickness and mass. So SHS or HHS or RHA plates. And it's really logical - LOS after main sight is smaller (in Arjun Mk.I) then gun mantled mask LOS, etc.

So in other way - Kunal had wrote very importand thnk about lack of the composite Armour behind FCS in Arjun Mk.1 - this fact give us conclusion that LOS there just must be really small (in othar way mass of pure SHS, HHS, or RHA protection will be to big)

 

[militarysta]

http://defenceforumindia.com/forum/land-forces/208-main-battle-tanks-armour-technology-369.html


here you have about CAWA armour on tank

 

[ersakthivel]

We do not need to waste our time and our health on to endless debate

Kunal Biswas talked with one of engineers, engineer more or less confirmed at least one feature of Arjun Mk1 turret that we were capable to observe and point out, which preaty much means our observations are correct

What is more important, me and Militarysta preaty much presented the results to tank enthusiasts community, and as far as I know, most of them (if not all), that have good knowledge and understanding of tank designing, agrees with these conclusions.

What Kunal confirmed was metallurgy was beefed up to meet the GSQR specs behind the main sight , without using composite armor,

So if LOS thickness for armor behind main sight is close to 650 mm RHA or (600 to 800 mm RHA)as can be deduced from the above measurements based on photos and if higher strength steel is used in place of normal turret grade steel this 650 mm has to be multiplied by a factor between 1.3 and 1.8 , which means close to 1000 mm RHA.

And if the same higher strength steel is used in mantlet , we can expect close to 700 to 900 mm normal RHA thickness besides the extra ERA protection for mantlet,

So that pretty much sums up there is no weak spot on ARJUN turret front,

No one needs to waste time and health in endless debate, Just one post with photo based measurements and any one can easily see that.

To cap it all , I am 100 percent sure that the Arjun tanks whose movie clips and photos of crew inside shown here are just prototype models to test the gun or engine or FCS or reliability of various sub systems.

So in actual protection models I am sure the armor arrangement will be far more better than this.

So tank enthusiast community can pretty much satisfy itself that arjun mk-1 is as well protected as any latest version of western MBTs as it is normal to expect from IA GSQR.

So if you cannot post any photo based measurement from the turret inside to support your inadequate 350 mm LOS behind the main sight besides the external photos , then I consider the argument to be closed and you don't have to reply to this post.

In the absence of such proof , Don't claim Arjun has weak mantlet and weak behind the main sight protection on behalf on any tank enthusiast community,

As technical drawing enthusiast community will always disprove such a baseless claim with few photos , there is simply no point indulging in such arguments,

Also the large vacant space of close to a meter ,inside, the turret between the roof top vision block and Tc's head offers enough scope for adding additional armor blocks as future APFSDS round penetration level increases

Thanks,

 

[ersakthivel]

more od less truth is here:





And this what Kunal posted is very important and really consist whit above estimatous. There is no composite Armour behind FCS[. Answer is simple - LOS after main sight is so small (thin) that there was no point to put there multilayer armour - becouse LOS is small nececcery was to put there something what shoud achive as big as it's possible protection in relation to thickness and mass. So SHS or HHS or RHA plates. And it's really logical - LOS after main sight is smaller (in Arjun Mk.I) then gun mantled mask LOS, etc.

So in other way - Kunal had wrote very importand thnk about lack of the composite Armour behind FCS in Arjun Mk.1 - this fact give us conclusion that LOS there just must be really small (in othar way mass of pure SHS, HHS, or RHA protection will be to big)

It is old, but not the complete truth , it is only partial truth

Full truth is in post no-5522 and 5524.

Pictures allude to the fact that the roof top vision block is slanted and another 300 to 450 mm armor space is there in the inside turret besides the 350 mm marked on your photos.

What Kunal confirmed was metallurgy was beefed up to meet the GSQR specs behind the main sight , without using composite armor,

You are making it out to suit your argument that there is only 350 mm LOS for armor behind mainsight , which is proved repeatedly as wrong with photo based measurements,

it is strange that You use photo based measurement on the out side of the tank to support your argument that there is only 350 mm LOS for armor behind main sight,

But when I use the same photo based measurements to prove 600 to 800 mm LOS for armor behind main sight , You choose to remain silent , unable to point out any mistakes in my measurement,

WHY?

So if LOS thickness for armor behind main sight is close to 650 mm RHA or (600 to 800 mm RHA)as can be deduced from the above measurements based on photos and if higher strength steel is used in place of normal turret grade steel this 650 mm has to be multiplied by a factor between 1.3 and 1.8 , which means close to 1000 mm RHA.

And if the same higher strength steel is used in mantlet , we can expect close to 700 to 900 mm normal RHA thickness besides the extra ERA protection for mantlet,

So that pretty much sums up there is no weak spot on ARJUN turret front,

No one needs to waste time and health in endless debate, Just one post with photo based measurements and any one can easily see that.

To cap it all , I am 100 percent sure that the Arjun tanks whose movie clips and photos of crew inside shown here are just prototype models to test the gun or engine or FCS or reliability of various sub systems.

So in actual protection models I am sure the armor arrangement will be far more better than this.

So tank enthusiast community can pretty much satisfy itself that arjun mk-1 is as well protected as any latest version of western MBTs as it is normal to expect from IA GSQR.

So many Arjun turret inside pictures are available on the net,

So if you cannot post any photo based measurement from the turret inside to support your inadequate 350 mm LOS behind the main sight besides the external photos , then I consider the argument to be closed and you don't have to reply to this post.

In the absence of such proof , Don't claim Arjun has weak mantlet and weak behind the main sight protection on behalf on any tank enthusiast community,

As technical drawing enthusiast community will always disprove such a baseless claim with few photos so easily , there is simply no point indulging in such arguments,

Also the large vacant space of close to a meter ,inside, the turret between the roof top vision block and Tc's head offers enough scope for adding additional armor blocks as future APFSDS round penetration level increases ,

Thanks,

 

[Dejawolf]

We do not need to waste our time and our health on to endless debate

Kunal Biswas talked with one of engineers, engineer more or less confirmed at least one feature of Arjun Mk1 turret that we were capable to observe and point out, which preaty much means our observations are correct

What is more important, me and Militarysta preaty much presented the results to tank enthusiasts community, and as far as I know, most of them (if not all), that have good knowledge and understanding of tank designing, agrees with these conclusions.

yes, having all steel protection for that area would be extremely inefficient, and not really sensible. the main reason front turret armour is 700-800mm thick is because its made of composite armour. and composites needs a lot of space to be efficient.
composites have high protection compared to density, but low protection compared to thickness.

another Armour estimate,
first estimate i just did SHS or single hardness steel with TE of 1.25. triple hardness steel is supposed to have a TE of 1.8, but is almost like glass so it needs to be backed with a more ductile material. assuming 40mm front and backing plate
40+40*1.25 = 90 RHAe
270*1.8 = 486mm RHAe
90+486 = 576mm rhae vs KE which is fairly close to the estimated thickness of the front turret.
of course, TE vs HEAT will suffer compared to other parts of the turret, which should be close to 900-1000mm vs HEAT instead of only 600mm.
and also it depends on whether india is capable of creating triple hardness steel reliably.

 

[Dejawolf]

demonstrating impossibility of 800mm behind sight. compare with interior pictures of arjun...
here gunners sight is right underneath the hatch, along with gunners computer.
trolling by Ershaktivel is obvious.

 

[ersakthivel]

demonstrating impossibility of 800mm behind sight. compare with interior pictures of arjun...
here gunners sight is right underneath the hatch, along with gunners computer.
trolling by Ershaktivel is obvious.

Obviously to hide the deceit , You will never mark any dimensions on your cartoon network type 3D models , which is a LEO art work by somebody else,

So this 3D model has nothing to do with Arjun turret.

For example the crew hatch is just 450 mm in width,

but the blue armor block in your model on which you have written ERsakthivel's 800 mm armor block is 2.5 times bigger than the crew hatch width , so scaling properly in your 3D model it is about 1200 mm thick,

But according to my measurement it is about 600 to 800 mm LOS,

So if you cut the size of blue block by a third you have space for gunner,

Such inconvenient little details are never important to you,

Since you are too busy filling all the gaps that shows up your mistakes with fancy colored rectangluar blocks , you just always forget to mark four consecutive dimensions (from turret tip to Tc' seat back totalling about 2500 mm) dimensions as per scale in all your 3D models,

just refer to my post no-5522 , 5524 for those four dimensions , and if you mark them on the model it will show up your faults

And sadly people who egg you on to post stuff like this have no knowledge of even these simple things,

Thats why instead of arguing about the details in my post no 5523 ,5524 ,

you post these patently wrong dimensionless 3D models again and again hoping to have the last word on the discussion,

But it is too late for that , I suppose,

yes, having all steel protection for that area would be extremely inefficient, and not really sensible. the main reason front turret armour is 700-800mm thick is because its made of composite armour. and composites needs a lot of space to be efficient.
composites have high protection compared to density, but low protection compared to thickness.

another Armour estimate,
first estimate i just did SHS or single hardness steel with TE of 1.25. triple hardness steel is supposed to have a TE of 1.8, but is almost like glass so it needs to be backed with a more ductile material. assuming 40mm front and backing plate
40+40*1.25 = 90 RHAe
270*1.8 = 486mm RHAe
90+486 = 576mm rhae vs KE which is fairly close to the estimated thickness of the front turret.
of course, TE vs HEAT will suffer compared to other parts of the turret, which should be close to 900-1000mm vs HEAT instead of only 600mm.
and also it depends on whether india is capable of creating triple hardness steel reliably.

All false estimate based on false dimensions on a wrong 3d model, No use in knowing the facts about Arjun,

In place of 270 put 600

600x 1.8=1080,

So 1080+ 90= 1170mm is the right estimate for the armor thickness behind main sight assuming the prototype shown in the film is the final production model.

 

[Blood+]

@members,
I have a doubt in my mind.You see,the design of Arjun and Leo 2A4 is quite similar (not identical) and both has got similar dimentions.Then why do you think that the combat weight of Leo 2A4 is around 54 tons where as Arjun MkI's is 59 ton or so?

Actually,looking at the Arjun and Leo 2A4,common sence dictates that Leo 2A4 with more armor on turret sides,thicker armor behind Gunner's Main Sight and higher turret should be heavier than Arjun MkI!! Yet Arjun MkI is heavier!Can someone here please solve this question of mine??

Thanks.

 

[Damian]

@members,
I have a doubt in my mind.You see,the design of Arjun and Leo 2A4 is quite similar (not identical) and both has got similar dimentions.Then why do you think that the combat weight of Leo 2A4 is around 54 tons where as Arjun MkI's is 59 ton or so?

Actually,looking at the Arjun and Leo 2A4,common sence dictates that Leo 2A4 with more armor on turret sides,thicker armor behind Gunner's Main Sight and higher turret should be heavier than Arjun MkI!! Yet Arjun MkI is heavier!Can someone here please solve this question of mine??

Thanks.

Tank physical dimensions is the key to your question.

You see, Leopard 2 is more compact than Arjun Mk1 (at least Leo2 turret is more compact), which means that internal volume can be protected by less armor volume, thus with better protection it can be lighter.

You must remember, that weight is not direct indicator of vehicle protection, it is old myth that some people believe in.

In such case sometimes a lighter tank can be protected better than heavier tank, however sometimes heavier tank is still better protected. In such case nobody should even look at weight, it can say something about vehicle, even it's protection, but can't be basis for definitive argument that vehicle A is better/worse protected than vehicle B.

It is far more complex issue, which can't be answered by simplified answer.

I will give you a good example.

Soviet medium tank T-64 weighted around 36-38 metric tons, however was better protected, more mobile and better armed than Soviet heavy tanks wich weighter more than 50 tons, why? Because it was more compact, smaller, and used some new design solutions.

Situation repeated later. For example Soviet main battle tank T-64A still weighted around 40 metric tons, but was more mobile (Leopard 1 and AMX-30 was equal in mobility with T-64A), better protected and better armed than some NATO MBT's like Chieftain, Leopard 1 or M60A1. Leopard 1 weighted approx 42 metric tons, while Chieftain and M60A1 more than 50 metric tons.

So you see, protection can't be juged purely on weight.

 

[methos]

@members,
I have a doubt in my mind.You see,the design of Arjun and Leo 2A4 is quite similar (not identical) and both has got similar dimentions.

The dimensions and the weight distribution are quite different. The Arjun has the MTU 838 engine, which is nearly as large/heavy as the MB 873, but consumes much more fuel. So the Arjun carries 1,610 l fuel, while the Leopard 2 carries only 1,200 l. Given that the transmissions of both tankshave the same weight, this means that the Arjun's powerpack is heavier.
But the powerpack and the much greater fuel volume, lead to a much longer hull. The Arjun's hull is therefore longer and wider.

Then there are a few odd design decisions, which increase the weight: One of them is the huge turret front (the turret is wider and probably also a little bit higher), the hull design (the heavy skirts cover more of the tank's sides, because DRDO decided to put ammuniton and fuel into the frontal section of the hull, while the Leopard 2 has only ammunition there) and the gun, which is longer but still worse than the L44 gun.

One factor that cannot be discounted is also the armour weight. The exact weight of the Kanchan armour or that of the Leopard 2's armour is unkown, as well is the exact efficiency.

PS:
The Leopard 2A4 weighs about 56 tonnes (exact value depends on from which batch the tank is), the Arjun 58.5 tonnes.

 

[Kunal Biswas]

Arjun height is shorter than Leo2 a4/a5/a6/a7 and so on, Comparison should be between rifle to rifle guns..

 

[methos]

Arjun height is shorter than Leo2 a4/a5/a6/a7 and so on, Comparison should be between rifle to rifle guns..

The total height of the Arjun is 3.03 m (including AAMG) according to DRDO Techfocus. The same figure for the Leopard 2 is 2.99 m and that with a greater ground clearance (550 mm for Leopard 2 vs 450 mm). I have serious problems believing the wikipedia figure of only 2.33 m roof height, because that's even smaller than a T-72.

And why should we compare the Arjun's gun with an rifled gun, when Blood+ wanted to compare the weight of the Leopard 2A4 and the Arjun? Read the previous posts before answering.

PS: Image: The T-55 is clearly smaller than the Arjun, hence the value from Wikipedia for roof height must be wrong.

 

[Kunal Biswas]

There is nothing disbelieving, Been on both tanks the height is more or less same ..

Wiki information is from DRDO site, I have posted the chart from DRDO site somewhere here in this thread, Care to read that ..

wikipedia figure of only 2.33 m roof height, because that's even smaller than a T-72.

PS: Image: The T-55 is clearly smaller than the Arjun, hence the value from Wikipedia for roof height must be wrong.

 

[methos]

There is nothing disbelieving, Been on both tanks the height is more or less same ..

It is more or less the same? Then you also could say that the height of the Leopard 2 is "more or less" the same as that of the T-55. I seriously doubt that you can "measure" a height difference up to 30-40 cm just by gut instinct.

Just look at the image. The T-55 is smaller than the Arjun tanks, despite it's roof height being 2.32 m. Here the BMP-2 is clearly smaller than the Arjun, while being (like the T-55) closer to the camera. The distance to the top of the gunner's sight is 2.4 m.

Wiki information is from DRDO site, I have posted the chart from DRDO site somewhere here in this thread, Care to read that ..

The DRDO TechFocus says that the total height is 3.03 m and thus greater than the total height of the Leopard 2. The DRDO or the Indian Army creates a lot of realy bad comparision tables like this or this where they coimpletely fail to pick the correct values or convert different measuring units.

 

[Kunal Biswas]

Warning, Don't troll ..

Dimensions>>

Overall length {with gun forward) : 10.638 m
Overall height {with gun rear) : 9.546 m
Overall height {with AD gun mount) : 3.03 m(Turret roof: 2.32 m)
Overall width : 3.864 m
Combat weight : 58.5 tons

Source : http://drdo.res.in:8080/alpha/drdo/English/mbt.html

It is more or less the same? Then you also could say that the height of the Leopard 2 is "more or less" the same as that of the T-55. I seriously doubt that you can "measure" a height difference up to 30-40 cm just by gut instinct.

Just look at the image. The T-55 is smaller than the Arjun tanks, despite it's roof height being 2.32 m. Here the BMP-2 is clearly smaller than the Arjun, while being (like the T-55) closer to the camera. The distance to the top of the gunner's sight is 2.4 m.

The DRDO TechFocus says that the total height is 3.03 m and thus greater than the total height of the Leopard 2. The DRDO or the Indian Army creates a lot of realy bad comparision tables like this or this where they coimpletely fail to pick the correct values or convert different measuring units.