Arjun Main Battle Tank (MBT)

[ersakthivel]

@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.

Reason is Arjun is made as per the IA GSQR, not for commonsense perception of general populace,

1. IA wanted Arjun to have a lower height profile than the LEO, because a LEO 24A will be more visible from to the enemy than the opponent,

it was the operational need of IA , which has operated T series of low height tank in Indo-Pak border,

So to cater to this need of IA which wanted a lower height tank with same protection features of leo 24A Arjun was made shorter than LEo but wider and longer than LEO 24A,

Thats why a few posters who repeatedly confuse themselves and others saying that only 350 mm of LOS is there behind main sight are unable to accept that Arju turret is longer than LEO 24A , while being lower than the LEo 24A turret,

So when you measure the thickness for armor protection it is not the tank's height that matters , what matters is how much LOS thickness is provided for armor across the turret and on the sides, So a shorter but longer and wider turret actually helps in offering better protection than the higher and narrower turret,

because Arjun's turret is wider and longer LEO , you just cannot plainly that Arjun turret should weigh lower than LEO,

It is the cubic meters of volume and armor inserts that determine the weight , not the height and width of the turret,

 

[ersakthivel]

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.

What you ignore is tanks with more weight provide for safer placement of ammo within the hull of the tank and have another extra crew member which was desired by the IA base on decades of operational experience,

While you can give the same LOS armor protection for the turret of a light weight, 3 man crew ,auto loader tank with much lower weight than the heavy weight 60 to tanks,

It is no use because any seep through explosion will ignite the unprotected ammo lying on the floor tank from exploding and destroying the tank, Auto loaders are also are inherently low protection arrangement and also you cannot have 4 men crew in the tank,

If you want to avoid this dangerous situation and have a tank safe from ammo cook off by the stored rounds along with extra crew member what you get is 4 man safe ammo storage in hull tanks like Arjun and LEO.

if you go by simple armor LOS calculation for turret you can say that light weight 3 men crew tanks too can provide the same protection as heavy weight tank , but if you go for a holistic safety approach along with growth potential and need for 4th crew member , light weight tanks will be unable to cater to this need .

So overall protection including safe ammo storage in hull with no fear of cook off and 4 men crew will always be judged by weight.

 

[ersakthivel]

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.

You should calculate the fuel consumption of both the tanks in hot indian climate to get a fair picture,

And there was no odd decisions the wider and longer hull was a GSQR need to have ,

1. lower height profile than the LEO , so the turret got wider but shorter than the LEO, to avoid being seen from a longer distance in the indian desert and punjab border areas,

2.a lower ground pressure per square inch which also called for wider tracks to distribute this weight,

Also the excess weight of the power pack may be just a couple of hundreds KGs more not a couple of tons more as you make it out to be,

And you don't even know the height of the Arjun tank, that is why you are ignorantly saying that Arjun turret has a huge front,Leo has a higher and narrower profile and Arjun has a shorter and wider profile,

What is needed for weight calculation is volume in cubic meters , not the simple height and width of the tank.

And simply you have no qualification to write the Arjun gun is worse than LEO as you are simply ignorant of the above points which resulted in Arjun's longer and shorter dimensions than LEO,

So with such dubious knowledge I don't know why you are fielding questions like an Arjun expert in this thread!!!!!!!!

So instead of actually spreading disinformation without any proper knowledge of ARJU try y to learn something useful about Arjun in this thread.

 

[Kunal Biswas]

Arjun from Autocar India 2004

Average kitna deti haa ??
Nice for a 58 ton monster..

Originally Posted by @bennedose, here >>http://defenceforumindia.com/forum/military-multimedia/53497-made-designed-india-war-machines-3.html

 

[Dejawolf]

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.

roof height of T-72 is 2.23m (cupola is a bit taller). roof height of my 3d model of arjun based on army-technology line drawings is 2.33m when other proportions such as width is correct.
so IMO this height is believable.
roof height of leopard 2A4 is 2.49m, and wikipedia height is wrong, its 2.79cm to the top of TC periscope.
low roof height is one of the reasons there's no room above the gunners head for extra armour in arjun. arjun turret is definitely wider, but width is used poorly, pretty much only to increase elbow room for loader and TC.

 

[Dejawolf]

Obviously to hide the deceit ,

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

.

and what do you base this frivolous assumption on?
because as a matter of fact the hatch hole width is 55cm wide, with the lid at 50cm

 

[Dejawolf]

@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.

Arjun sideskirts are longer and heavier than leopard skirts, and arjun has a heavier gun (2025kg vs 1150kg) arjun also has wider and heavier tracks than leopard 2A4.

 

[ersakthivel]

and what do you base this frivolous assumption on?
because as a matter of fact the hatch hole width is 55cm wide, with the lid at 50cm

How do you close a 550 mm width hacth hole,

with

a 500 mm lid?

Please explain,

It is common sense that the hole dia should be lower than the lid dia ,

Now you are proposing to cover a 550 mm dia hole

with

a 500 dia cover(lid),

So what covers the remaining 50 mm dia of the hole(25 mm on each sides)

If my assumption is frivolous , Is this great "matter of fact " finding of yours is based on Einsteen's theory of relativity perhaps,

Do you even faintly remember that these dia for the hatch hole lid was arrived at after comparing the face width(from Wiki averages) of the man standing in the hatch hole in relation to the perpendicular hatch lid width behind him?,

So if you are exposed for the wrong 3D model you posted here, that does not mean my assumptions are frivolous,

they were all arrived at after comparing them with photographic evidence, (post no-5522, 5524 in this thread)

not a single one of which you were able to refute,

please note.

roof height of T-72 is 2.23m (cupola is a bit taller). roof height of my 3d model of arjun based on army-technology line drawings is 2.33m when other proportions such as width is correct.
so IMO this height is believable.
roof height of leopard 2A4 is 2.49m, and wikipedia height is wrong, its 2.79cm to the top of TC periscope.
low roof height is one of the reasons there's no room above the gunners head for extra armour in arjun. arjun turret is definitely wider, but width is used poorly, pretty much only to increase elbow room for loader and TC.

Wrong prognosis, there is room for extra armor block over the gunner's head in Arjun,

still it is not provided , why?

Because the front turret of Arjun is also longer than the LEO, So the this extra depth equals the thickness of the extra armor block in Arjun.


It has already proven beyond doubt in this thread with photo based evidence on evn rudimentary prototype models and you were unable to refute it.

Los for armor behind main sight is close to 800 mm and with better metallurgy steel in actual RHA calculation it will exceed 1000 mm, Thats why no armor block was there over gunner's head.And in future if penetration levels of the anti tank rounds increase extra armor will be added as well.

Do you have any proof that the height difference at the roof level of mere 200 mm will shut out the space for extra armor?if you have post it.

 

[Dejawolf]

How do you close a 550 mm width hacth hole,

with

a 500 mm lid?

Please explain,

with a 55cm wide hatch. the 2.5cm lip is there to lock the hatch in place when it's closed.
now tell me how you arrived at a 45cm width for the hatch based on my picture?

 

[Kunal Biswas]

May help ..

 

[ersakthivel]

with a 55cm wide hatch. the 2.5cm lip is there to lock the hatch in place when it's closed.
now tell me how you arrived at a 45cm width for the hatch based on my picture?

You wrote that the hole is 550 mm wide and the lid is 500 mm wide in your post,

I used none of your pictures to arrive at hatch cover width,

It was done based on the face width of the crew member standing in front of the vertical open hatch cover in this thread.

 

[Dejawolf]

You wrote that the hole is 550 mm wide and the lid is 500 mm wide in your post,

I used none of your pictures to arrive at hatch cover width,

It was done based on the face width of the crew member standing in front of the vertical open hatch cover in this thread.

yeah i wrote it that way because you'd probably misunderstand it if i wrote the hatch hole was 500mm with an edge at 550mm where the hatch would fit inside.
i mean, just look at the damn picture and you will see that there's no inconsistency in the model
and if you used none of my pictures, then you couldn't possibly determine the size of the armour block in my picture.
same model from top view. black rectangles are 10cm increments as always..

 

[ersakthivel]

yeah i wrote it that way because you'd probably misunderstand it if i wrote the hatch hole was 500mm with an edge at 550mm where the hatch would fit inside.
i mean, just look at the damn picture and you will see that there's no inconsistency in the model
and if you used none of my pictures, then you couldn't possibly determine the size of the armour block in my picture.
same model from top view. black rectangles are 10cm increments as always..

If you mark A+B+C=2500 mm(2500 mm) i.e 700+ 800+1000=2500 , you too can know something about armor thickness

A=700mm is the depth of the sight cutaway from turret gun front covering plate tip,

B=800 mm LOS for the armor behind main sigh,

C=1000 mm(500+500) , the distance from the roof top vision block opening inside the crew compartment and the back of the TC seat headrest,

So do it, the reason people draw pictures are not just for coloring but to mark dimensions,

2500 is the distance between the Tc seat back and turret front tip(from the cover plate of the gun)

But I know what values you will give to A, B,C

for A you will give 700 mm
for B you will give 380 mm
for C you will give the remaining 1420 mm

Which is patently wrong.

The value for C is between 1000 to 1150 mm,
refer to my posts 5522, 5524 for details

 

[Dejawolf]

for A you will give 700 mm
for B you will give 380 mm
for C you will give the remaining 1420 mm

Which is patently wrong.


refer to my posts 5522, 5524 for details

everyone can see that 800mm behind sight is completely ridicolous.

 

[ersakthivel]

everyone can see that 800mm behind sight is completely ridicolous.

That every one includes just you and just a few other guys posting BS in this forum,

The point is you have pushed your 380 mm LOS behind the man sight theory to the hilt for months,

And now suddenly confronted with evidence to the contrary from the newly released blue mango film , you are giving ridiculous tags to me.

 

[Dejawolf]

That every one includes just you and just a few other guys posting BS in this forum,

The point is you have pushed your 380 mm LOS behind the man sight theory to the hilt for months,

And now suddenly confronted with evidence to the contrary from the newly released blue mango film , you are giving ridiculous tags to me.

what evidence to the contrary? you haven't put up a single convincing argument. you managed to screw up the measuring point for the TC's back rest, and when you were told multiple times that you had it wrong, you completely ignored it. THE BACK REST IS LOCATED UNDER THE HATCH HOLE NOT AT THE BACK OF THE TC CUPOLA RING. THE SOLDIERS IN THE TANK ARE PROPORTIONAL. the gunner won't FIT with 800mm behind the sight.
what part of this is so damn hard to understand? it is clear as glass from the above picture that NONE of the inconsistensies you claim to be present, are present.

 

[ersakthivel]

what evidence to the contrary? you haven't put up a single convincing argument

post no-5522,5524 are convincing enough besides a raft of others posts a few pages before for which you have no reply to make

. you managed to screw up the measuring point for the TC's back rest, and when you were told multiple times that you had it wrong, you completely ignored it. THE BACK REST IS LOCATED UNDER THE HATCH HOLE NOT AT THE BACK OF THE TC CUPOLA RING.

If the back rest is located under the hatch hole,

DO You expect the Tc to sit on the back rest and ride the tank like the old horse or mounted cavalry days with each of his legs on each side of th Tc backrest?

The back rest which is right under the back edge of the hatch hole,right under the point of vertical hatch cover in BR line drawing is 2500 mm behind the front tip of the turret gun covering plate at the turret front, You don't plead ignorance of this simple dimensional fact again and again in your vain attempt to screw the forum .

THE SOLDIERS IN THE TANK ARE PROPORTIONAL. the gunner won't FIT with 800mm behind the sight.
what part of this is so damn hard to understand? it is clear as glass from the above picture that NONE of the inconsistensies you claim to be present, are present.

So gunner and Tc will fit very well within the 1000 to 1200 mm gap in the crew compartment with Tc's leg room going over the right shoulder of the gunner.

 

[Dejawolf]

DO You expect the Tc to sit on the back rest and ride the tank like the old horse or mounted cavalry days with each of his legs on each side of th Tc backrest?.

No i do not, but apparently you do. and you also expect the gunner to be unable to sit inside the tank. i've said it before a hundred times, and i'll say it again.
it's not 2500mm between front tip of armour to TC backrest, but about 2250mm. as evidenced in multiple pictures.
only in your religious arjun worshipping mind is it anything else. i've demonstrated the impossibility of your concept in more than just one way,
not to mention the fact that a solid block of steel 800mm thick behind already 750mm of composites would make the arjun far heavier than 58 tons.
you had nothing to counter it with, except false accusations about the hatch hole being 450mm wide when it is demonstrably not, and some completely random insults about me not making the 3d models. it all demonstrates your complete lack of knowledge on the subject.

 

[Dejawolf]

Arjun modeling:

 

[Damian]

Hmmm, Dejawolf, I have a good feeling that this model might some day find it's way in to SB Pro PE?