Arjun Main Battle Tank (MBT)

[ersakthivel]

1. You dont need photoshop to measure lengths, you can just as easily do it with a ruler/scale. Your measurement ignores perspective and the distortion introduced by the wide angle lens. In order to deduce the length of an object by comparing it with an object of known size by using simple linear scaling, the two objects *must* be at the same distance from the lens. Therefore, if you want to deduce the width of the turret by comparing the number of pixels it occupies to the number of pixels occupied by the hull, both measurements must be made at the same plane/line in the picture.

If you do that using the inner red and the blue parallel lines you have drawn, the ratio of the turret:hull = 10:12.

If hull width at that point = 3.86m, turret = 3.21m
If hull width at that point = 3.75m, turret = 3.12m
If hull width at that point = 3.5m, turret = 2.91m.

Its impossible to reconcile the picture you have posted with a turret width of 2.84 meters.

2. My second point is about the gun mantlet. The size of that thing is huge! in fact it takes up almost 1/3rd of the frontal face of the turret. In size, its comparable to the 'cheeks' of the turret. Now, if the mantlet cant be armored, its logical to keep its size as small as possible. Why would Indian designers make it perhaps the largest mantlet on a tank in the whole world? They have been manufacturing the tiny T72 mantlet for decades now, its not as if they dont know how to make a small mantlet that can take the recoil. To me, the deduction is, that It is not a weak spot in the turret, it is made of composite armor, and is as protected as any other frontal part of the turret face.

3. About ammo containerization. Broadsword: Heavier, more lethal Arjun tank poised for trials An excerpt from the article, quoting the designer of the tank, GK Kumaravel. "We also now have an ammunition containerisation system. If the tank is hit, and the on-board ammunition explodes, it will blow outwards, saving the crew. A metallic box with 'blow-off panels' directs the explosion outwards,". When the designer of the tank is saying something, I would take it at face value. Perhaps not the Mk1, but the Mk2 definitely has the blow out panels needed for safety against ammo cookoff.

 

[ersakthivel]

You gotta ask your school to give you the money back.
STGN

the two objects *must* be at the same distance from the lens. Therefore, if you want to deduce the width of the turret by comparing the number of pixels it occupies to the number of pixels occupied by the hull, both measurements must be made at the same plane/line in the picture.
SKJ

you can pay your hard earned money to some drawing class and learn something, is my hope.

 

[skj]

OMG. See the blue slanted lines to the side?? they follow the outside of the armoured skirts, they follow the perspective because the skirts are horizontal you can do that. Now where the blue vertical lines connect with the perspective lines is where the edges of the turret is seen from the side so at the middle of the rear armour skirt. That is how I make a level plane for the edges of the turret.
But wait what happens if I use the same numbers that I got from using that plane to calculate the turret width on the red lines which followed the perspective lines of the hull with out skirts??
oh thats right 3.56, oh boy that is weird thats the same numbers you get, when we take in account the crude simplification to 10:12, when you use the turret shadow. What do you know you have proven me right thanks skj! And its just wider than the tracks, my oh my how everything seems to fit together its almost like I made a pretty accurate estimation.
STGN

Come on ersakthivel, be a man(or woman if thats what you are, no disrespect) and admit you where wrong.

My dear fellow, you confuse precision for accuracy. Its better to have an approximate figure that is correct, than a precise figure that is wrong.

My ED is a little rusty, its been more than a decade and a half after all, but I still have enough to compare the length of a straight line to one in the same plane in a photograph. I have no interest in internet pissing contests. Just thought I would share something I knew with the rest of the forum. People who want to figure it out and have a scale handy, can do it themselves. If anyone comes to something other than 10:12, do let me know.

 

[ersakthivel]

It is the problem when people think they know engineering drawing and perspective drawing,
by simply having access to PHOTOSHOP and pixel measurements,
and chopping some photographs at will.
In perspective drawing the object that is closer to the observer always appear bigger,
The same object that is 2 meter back appears very smaller,
That is the reason that that by drawing projection lines they must all be brought on a relative same plane before making measurements.

if you look at the hull in front ,
and the same hull near the point of crew hatches ,
you can see how it reduces size in appearance by atleast 20 percent for 2.6 meter length of the hull,

Does that mean they whether the hull reduces in size in reality?
NO.
It is same as looking at the tracks standing at the center of railway track and saying at the farthest distance tracks join together.

Same problem here, if we draw the correct projection line we can see the difference.

 

[STGN]

My dear fellow, you confuse precision for accuracy. Its better to have an approximate figure that is correct, than a precise figure that is wrong.

My ED is a little rusty, its been more than a decade and a half after all, but I still have enough to compare the length of a straight line to one in the same plane in a photograph. I have no interest in internet pissing contests. Just thought I would share something I knew with the rest of the forum. People who want to figure it out and have a scale handy, can do it themselves. If anyone comes to something other than 10:12, do let me know.

Wait a minut is it you or ersakthivel who has that degree?? or what am facing two mechanical drawing engineres who are either incompetent or purposfully misunderstanding the subject at hand.
I aint confusing anything I have stated from the start that these numbers are not 100% accurate look back at my posts. And as I said yes 10:12 is aproximatly right its the same numbers I get that is a 3.56 hull width 2.84 width turret thats ~10:12,5 your numbers vidicate my estimation.
STGN

 

[STGN]

It is the problem when people think they know engineering drawing and perspective drawing,
by simply having access to PHOTOSHOP and pixel measurements,
and chopping some photographs at will.
In perspective drawing the object that is closer to the observer always appear bigger,
The same object that is 2 meter back appears very smaller,
That is the reason that that by drawing projection lines they must all be brought on a relative same plane before making measurements.

if you look at the hull in front ,
and the same hull near the point of crew hatches ,
you can see how it reduces size in appearance by atleast 20 percent for 2.6 meter length of the hull,

Does that mean they whether the hull reduces in size in reality?
NO.
It is same as looking at the tracks standing at the center of railway track and saying at the farthest distance tracks join together.

Same problem here, if we draw the correct projection line we can see the difference.

It is the problem when people who don't know what they are talking about tries to refute others, especialy people who claim education credentials, but clearly shows they have non of the sort.
You don't seem to understand but I have actually done what you are accusing me of not doing thats why my and skj's numbers are very close to each others even if he use more unreliable(they kinda change based on the light source location) shadows for his numbers.
You are, I hope purposfully, misreading my photo. Its funny I already had a hunch that you where incapable of understanding the photo. Let me say it one last time. The blue slanted lines to the side follow the perspektive lines of the outside of the armor skirts. The blue vertical lines furthest from the center creat a level plane from one side to the other pretty close turret edges. This belive it or not takes the perspektive into account. The red line is on the same plane only following the hull edges less skirts.
STGN
But go on, ersakthivel how low can you go, are you sure you don't have more Indian American mechanical drawing buddies to chime in to waist our time.

 

[ersakthivel]

It is the problem when people who don't know what they are talking about tries to refute others, especialy people who claim education credentials, but clearly shows they have non of the sort.
You don't seem to understand but I have actually done what you are accusing me of not doing thats why my and skj's numbers are very close to each others even if he use more unreliable(they kinda change based on the light source location) shadows for his numbers.
You are, I hope purposfully, misreading my photo. Its funny I already had a hunch that you where incapable of understanding the photo. Let me say it one last time. The blue slanted lines to the side follow the perspektive lines of the outside of the armor skirts. The blue vertical lines furthest from the center creat a level plane from one side to the other pretty close turret edges. This belive it or not takes the perspektive into account. The red line is on the same plane only following the hull edges less skirts.

No one can take perspective into account in his mind in any drawing,


In true perspective drawing all the lengths must be projected in the same plane to get the correct comparision.

SKJ did not endorse your dimension.he pointed out this mistake.

He exactly pointed out this mistake you made in this drawing.

What is the meaning of his words 10:12 ratio for turret: hull width?

OK ,I will do the correct projection and upload a picture shortly.

I have trouble uploading pictures in this site from my flicker account.

STGN
But go on, ersakthivel how low can you go, are you sure you don't have more Indian American mechanical drawing buddies to chime in to waist our time.

first of all know the correct spelling-------- perspective
You have written-------------------------------------perspektive

What kind of argument I can advance in a discussion with a guy who doesn't even know the spelling of perspective drawing and armed to the teeth with few photoshop tools .

 

[STGN]

first of all know the correct spelling-------- perspective
You have written-------------------------------------perspektive

What kind of argument I can advance in a discussion with a guy who doesn't even know the spelling of perspective drawing and armed to the teeth with few photoshop tools .

Ran out of bad arguments I see, and you are in a really bad position to criticize others of their English language skills. But fair enough that is spelled wrong, it is because I am Danish and in Danish the word for perspective is "perspektiv" and we frequently use k instead of c so it happens that I mix the two up when I am typing using 10 finger system.

I am ready for that apology now, where you say that you are sorry for lying and distorting my words. And that you agree that you where wrong in defending a turret width of 3.2m and that the current evidence shows something much closer to ~2.84m.
STGN

 

[skj]

Wait a minut is it you or ersakthivel who has that degree?? or what am facing two mechanical drawing engineres who are either incompetent or purposfully misunderstanding the subject at hand.
I aint confusing anything I have stated from the start that these numbers are not 100% accurate look back at my posts. And as I said yes 10:12 is aproximatly right its the same numbers I get that is a 3.56 hull width 2.84 width turret thats ~10:12,5 your numbers vidicate my estimation.
STGN

Your quarrel with ersk is your own, I dont want any part of it. FWIW, I have a EE Bachelors and a CS Masters. All engineers in India have to take at least one or two ED Courses. So yes, in my mind, there is no doubt that you are making a mistake about the size of the turret. Anyone who has a scale can verify what the ratio of the turret:hull is, provided they take the ratio at the right pt.

here is another picture for you to work on. Watch Out! [www.bharat-rakshak.com]

If as shown in the last discussion, the ratio of the turret : (hull size - armored skirt) == 10:12

Given that the hull size is 3.86 meters, you can easily calculate the hull size -armored skirt ~= 3.7 meters, and you arrive at approximate turret size of ~=3.1 meters. Now if the armored skirt is not included in the hull width, you will end up at an even wider turret..

*Edited later, actually closer to 3 meters than 3.1.

 

[STGN]

Your quarrel with ersk is your own, I dont want any part of it. FWIW, I have a EE Bachelors and a CS Masters. All engineers in India have to take at least one or two ED Courses. So yes, in my mind, there is no doubt that you are making a mistake about the size of the turret. Anyone who has a scale can verify what the ratio of the turret:hull is, provided they take the ratio at the right pt.
Great, then don't use the same arguments as he does.

here is another picture for you to work on. Watch Out! [www.bharat-rakshak.com]


If as shown in the last discussion, the ratio of the turret : (hull size - armored skirt) == 10:12
I disagree its closer to ~10:12.5

Given that the hull size is 3.86 meters, you can easily calculate the hull size -armored skirt ~= 3.7 meters, and you arrive at approximate turret size of ~=3.1 meters. Now if the armored skirt is not included in the hull width, you will end up at an even wider turret..
You can also easily calculate wrong apparently?


*Edited later, actually closer to 3 meters than 3.1.
Great so we have already shaved of upwards 100-200mm of that old claim

LOL lay off the rulers man:

So even if we use your god given 10:12 number we cut .25m of 3.2m turret but as I have shown these numbers are very close to the numbers I got from my turret calculation so your 10:12 number like your 3.7 hull is probably a bit off.

BTW why are you guys so eager to make the turret so wide? The bigger the barn the easier it is to see and hit. I mean if we average out the sloping turret of an Abrams its only 2.85 m wide.
STGN

 

[Damian]

BTW why are you guys so eager to make the turret so wide?

You don't know? The old truth the bigger the better!

 

[skj]

LOL lay off the rulers man:

So even if we use your god given 10:12 number we cut .25m of 3.2m turret but as I have shown these numbers are very close to the numbers I got from my turret calculation so your 10:12 number like your 3.7 hull is probably a bit off.

BTW why are you guys so eager to make the turret so wide? The bigger the barn the easier it is to see and hit. I mean if we average out the sloping turret of an Abrams its only 2.85 m wide.
STGN

It is what it is, its not going to change by my pixel poking. I simply gave a rough (but correct) approximation of the hull:turret ratio of 12:10 at the point where the turret meets the hull. Since the hull width at that point was not known at the time, I said that the turret would be 3.2 meters wide, if the hull at that point was 3.86 meters wide.

In your picture above, you have an unstated assumption, which is the width of the tank including the armored skirts is 3.86 meters.

The other thing is, you are not taking into account the fact that the inner armor skirt extends for the entire length of the tank. Therefore the width of the hull at the point where the hull meets the turret is a bit wider, which will give you a turret width of ~3 meters.

Anyway, a slightly larger turret is not going to make any difference in the age of advanced FCS, radar/TI guided weapons.

 

[skj]

I think I am wasting my time here, you guys cant even read a scale properly, and pretend as if you are tank experts of some kind. I have interacted with engineers from all over the world, people respect data, state assumptions and are ready to accept unknowns instead of extrapolating based on whims. You guys wont last a couple of days with this attitude.

 

[Damian]

Anyway, a slightly larger turret is not going to make any difference in the age of advanced FCS, radar/TI guided weapons.

It will. There is no such thing like a projectile hitting directly where crosshair of the sight is placed, not to mention that especially at the long range, it is immposible to even aim at any specific point on the enemy tank, simply because enemy tank is a blob at such distance.

Most tanks have a main sight for TC and gunner with 3x wide field of view zoom for observation and 10-12x narrow field of view zoom for aim and engagement.

The only tanks I know, that have better electrooptics are M1A1SA/FEP and M1A2SEP that have 3x and 10x for the universal day/thermal channel ocular and have 3x, 6x, 13x, 25x and 50x zoom for thermal channel biocular. AFAIK TC panoramic CITV have similiar zoom.



And this still does not guarantee that you will hit a specific spot. Such thing as rounds dispersion is very real for tank guns aimed by use of modern FCS, same goes for ATGM's, in their case it is also immposible to precisely aim in the specific spot, maybe besides ATGM's like Spike that can be precisely guided via cable.

I also suggest to seek photos of targets on tank ranges, you will see that there is clearly visible projectiles dispersion.

Or if someone would wish to really check out how to use modern tank fire control system I suggest to purchase Steel Beasts Pro PE, it is a civilian version of the military version Steel Beasts Pro. It costs only 100USD.

http://steelbeasts.com/


And a video that shows more or less how it looks like, but to really experience it, you need to use it.

SB Pro PE is used by several militaries aroud the world, so it is not a silly game.

Note - videos shows older version of the software.

 

[militarysta]

I

Most tanks have a main sight for TC and gunner with 3x wide field of view zoom for observation and 10-12x narrow field of view zoom for aim and engagement.

The only tanks I know, that have better electrooptics are M1A1SA/FEP and M1A2SEP that have 3x and 10x for the universal day/thermal channel ocular and have 3x, 6x, 13x, 25x and 50x zoom for thermal channel biocular. AFAIK TC panoramic CITV have similiar zoom.

Leopard-2A5 and 2A6 it's 3x 12 = 36x zoom ;-)
And Im reall sure that values.

BTW- Damian have right, about aiming to the tank - espacially durning moving. To many factors s taking when we are talking about "accuracy" for example:

- amuniction accuracy
- barrell accuracy when it;s "cold" and when it's "hot" (after few rounds)
- whole gun accuracy (gun amortisation system (I haven't propper word in english)
- how are accurate gun mounted points
- main sight error and it's accuracy
- precision of main balistic computer
- precision of the turret ring (bearing)
- the ability of the suspension to dampen vibrations
- quality of the FCS
- ergonomic of the crew positions/sights/joysticks etc -very important!
- how crew is trained.
And this is only small part

 

[skj]

It will. There is no such thing like a projectile hitting directly where crosshair of the sight is placed, not to mention that especially at the long range, it is immposible to even aim at any specific point on the enemy tank, simply because enemy tank is a blob at such distance.

And this still does not guarantee that you will hit a specific spot. Such thing as rounds dispersion is very real for tank guns aimed by use of modern FCS, same goes for ATGM's, in their case it is also immposible to precisely aim in the specific spot, maybe besides ATGM's like Spike that can be precisely guided via cable.

I also suggest to seek photos of targets on tank ranges, you will see that there is clearly visible projectiles dispersion.

Or if someone would wish to really check out how to use modern tank fire control system I suggest to purchase Steel Beasts Pro PE, it is a civilian version of the military version Steel Beasts Pro. It costs only 100USD.

STEELBEASTS.COM · HOME

And a video that shows more or less how it looks like, but to really experience it, you need to use it.

SB Pro PE is used by several militaries aroud the world, so it is not a silly game.

Note - videos shows older version of the software.

That is your opinion. Obviously the Indian designers disagree with that and made their own design, going for a wider turret. Now each design has its own shortcomings and advantages. Engineering is tradeoffs, you can choose to emphasize one aspect of your design over the other. There is no absolute truth. Enthusiasts can only analyse what the trade offs are, and fantasize about what perhaps they may have done differently, assuming they know all the constrains under which the designer was working and what he/she was trying to achieve. It is certainly possible that Arjun design is suboptimal and better armor placement is possible, but to ignore measurements/data that is in your face, and to push the theory that the designers know less than you is just plain ridiculous. In fact that shows preconceptions ruling over a methodical approach and a basic lack of integrity.

 

[militarysta]

That is your opinion. Obviously the Indian designers disagree with that and made their own design, going for a wider turret.

Or they just haven't choice cose to lack of enought good technology avaible in India in those years.
a) lack better gun = we have big gun mantled mask
b) lack armour with better weight efficency = we have extremly short turret sides "spacial armour" cavity
c) lack of brains = we have non isolated ammo rack in turret (without blow out pannel, without munition "bunker") next to 50-60mm thick RHA plate

 

[Damian]

That is your opinion.

That is not my opinion, but opinion of tank designers all around the world.

Obviously the Indian designers disagree with that and made their own design, going for a wider turret.

It seems that for some reason you like to discredit years of experience in tank designing of nations that design them for a much longer time, and show that if it will be justified, you will design wheel again.

Sorry but our western mentality just can't comprehend such curious behavior.

and to push the theory that the designers know less than you is just plain ridiculous.

Neither of us said such thing. What we want to say is that DRDO engineers needs to learn more, we base this on our comparision of their design to designs made by more experienced design bureaus from around the world.

And we actually wonder, why instead of base design on reliable solutions, there is so much "making it our way" which in the ends means making the same old mistakes as the more experienced design bureaus made, and improving things that were long time ago improved by others and put to perfection.

Can you explain this approach? I have my theory but, I will keep it to myself.

 

[skj]

Or they just haven't choice cose to lack of enought good technology avaible in India in those years.
a) lack better gun = we have big gun mantled mask
b) lack armour with better weight efficency = we have extremly short turret sides "spacial armour" cavity
c) lack of brains = we have non isolated ammo rack in turret (without blow out pannel, without munition "bunker") next to 50-60mm thick RHA plate

This is the type of nonsense I am talking about. You simply have some preconceived racist notion and are not afraid to flaunt it.

What is the relationship between a 'good gun' and mantle size?
Edited later.
1. Only the first 125 tanks have the turret ammo without the blow off panels. I have posted an interview with the tank designer, who says that Mk2 has turret blowoff panels. I think Ill take his word over some random guy on the internet.
2. You guys confuse precision for accuracy. These are two different things you know. A figure can be very precise but completely wrong. You claim 60mm RHA plate for turret sides as if you have measured it personally. All you have done is to take some pictures and done some asinine projections from them. Regardless, 60mm or 160mm, its not your opinion that matters, it between the tank designers and the customer. You can rant all you want, it wont make one bit of difference.

 

[skj]

That is not my opinion, but opinion of tank designers all around the world.



It seems that for some reason you like to discredit years of experience in tank designing of nations that design them for a much longer time, and show that if it will be justified, you will design wheel again.

Sorry but our western mentality just can't comprehend such curious behavior.



Neither of us said such thing. What we want to say is that DRDO engineers needs to learn more, we base this on our comparision of their design to designs made by more experienced design bureaus from around the world.

And we actually wonder, why instead of base design on reliable solutions, there is so much "making it our way" which in the ends means making the same old mistakes as the more experienced design bureaus made, and improving things that were long time ago improved by others and put to perfection.

Can you explain this approach? I have my theory but, I will keep it to myself.

Lets understand what you have done here, you have drawn a few straight lines, and you pretend as if you are the second coming of Euclid. Grow up, any idiot can draw these simple geometrical patterns. You are not privy to what constraints the Indian designers were working with.. In any case, this is not a question of 'western' or 'eastern' mentality, its a matter of enthusiasts forgetting the extent of their knowledge. Regardless of the plumage you want to adorn yourself with, there is a reason why you are spouting off on an internet board and the Indian guys are designing a real life tank. You cant even make a simple measurement from a head on photograph and are putting forwards all sorts of nonsense and 'clever' racist claims.