Arjun Main Battle Tank (MBT)

[Dejawolf]

can u also try on Arjun Mk2, if possible.
Thanks!!

heh, i'm not even halfway done with the mk.1 yet. probably gonna have to spend at least 15-30 more hours before it starts looking decent.

here's another WIP:

 

[pmaitra]

@Dejawolf, thank you for the hard work. Your model looks great.

 

[ersakthivel]

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

pmaitra,
In the link above human head average measurements are given,

In that table the height of the human head from chin to skull is given as 23.2 mm for 50 percent of males in item no-14.

In the picture posted above 1.7143 is the ratio of this human head height to the Tc seat head rest behind him at a point close to the left side edge of the head rest.

So the height of the head rest is 23.2/ 1.7143= 13. 53 mm,

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

In the picture below the ratio of the [horizontal distance between the back of the TC head rest ] / [height of the Tc seat head rest is ] = 95

So 95 x 13.53 = 1294 mm



So it is beyond any doubt that the distance between the back edge TC seat back rest and the inside opening for the vision block above gunner main sight eye piece is 1294 mm approx

In the picture above , In the same way the ratio of [ distance from front tip of the turret(excluding the gun cover plate) to the pivot base of the hatch cover ] / [ distance from tip of the turret (excluding the gun cover plate) to for hatch cutaway ] is 3.14 .

In the image below distance from front tip of the turret(excluding the gun cover plate) to the pivot base of the hatch cover is 2250

[Actually the back edge of the back rest is situated at a point more than 2400 mm behind the front tip of the turretexcluding the gun cover plate , since pivot base is about 150 plus mm infront of the vision block over Tc's seat head rest.

but to avoid needless controversy I have decided to let go off the extra 150 mm even though taking it into account will increase the LOS number by another 150 mm ,

But for the time being I will avoid taking this 2400 mm as the distance for calculation]

so 2250 / 3.14 = 716 mm is the gap for the hatch cutaway.

.

So 1294=216= 2010 mm that is ,

SO 2500 mm -2000 =500 mm is the LOS for main sight in the prototypes versions shown in blue mango film.

Also in the picture below the height of the roof top vision block opening is at least 200 mm below the inside turret roof,because this small rectangular opening for light is in line with the bottom of the vision block over Tc head.

ofcourse the roof top vision block is located on the turret top sloping towards the front,

But at the point of roof top vision block the slope is very small far less than 200 mm, See here in the picture below,

So this small slope cannot justify the position of the roof top vision block opening inside the crew compartment at a height 200 mm below the turret roof.

SO it you magnify the image below close to 400 percent you can clearly see the inside opening of the vision block is cut on a slanting armor wall.

And this slanting armor wall extends much further after the opening for the light, look at the photo below,
above the orange or yellow colored dial box with black buttons

We can see that here in the photo below as a white downward hanging slab wee below the turret roof level on which a red wire type strip is sticking out.

So there is some armor even after the opening for the roof top vision block,

Another crucial point is close to 30 percent of the height of the vision block is in front of the close to 50 mm (need clarification)thick turret roof plate.

So LOS will definitely be the same as that of the LEo as 640 mm for this A1 section.

I have no doubts about it because it is mostly modelle on Leo.

Even that 500 mm LOS is taken from the back edge of the TC seat , because I don't want any lower measurement than this challenging it here,

If we use the front surface of the TC seat head rest as 2500 mark(it is true in reality ) then LOS will come above 600 mm


Please post your opinion.

 

[ersakthivel]

@Kunal Biswas

@sayareakd

Sir please check the above post no-262 and give your opinion ,

as there is no point in dragging this single issue for hundred pages.




So it the metallurgy of the portion behind the main sight is different y we can multiply the LOS by a factor of 1.3 to 1.8

So any way the RHA for LOS behind main sight is close to 1000 mm, even for the prototypes ,

Also what we see on the front is covering plate for the gun, And mantlet plate is close to 400 to 500 behind the covering plate is production line photos , So if better metallurgy is used here protection will also be substantially more than the normal RHA calculation.

 

[ersakthivel]

no it's not.
No single of your ideas is correct:

Both draw in the same scale (I had rescaled Arjun draw to the same scale as Leo-2A4 draw.).






And Yes, in arjun end of backplate is in the same place when in Leo-2 is additional turret roof periscope for loader. But in Leo-2 is in HALF of the armour cavity (circa 325mm) and in Arjun is in the end. And LEo-2A4 have smaller EMES-15 sight block then Arjun sight. More or less - again - LOS after main sight in Arjun is half or less then half LOS after main sight in leo-2A4.


PS.the common pont is turret base line, not track or hull. The aim was to compare turret dimension, not whole tank!

I have pin pointed the inside opening of roof top vision block in the post no-262 , so there is no meaning in saying," end of backplate is in the same place when in Leo-2 is additional turret roof periscope for loader".

Even that 500 mm LOS is taken from the back edge of the TC seat , because I don't want any lower measurement than this challenging it here,

If we use the front surface of the TC seat head rest as 2500 mark(it is true in reality ) then LOS will come above 600 mm

If you can not refute the logic behind the points raised in post no-262 above ,

there is no meaning in any of your estimation of LOS of Arjun

with obscure comparison with LEO (and that too with no dimensions ) for any practical purpose,

 

[militarysta]

with obscure comparison with LEO (and that too with no dimensions ) for any practical purpose,

two dimension visible from Arjun draw and eight on Leo-2A4 factory draw is indeed "no dimensions"


You have four draws whit compare Leo-2A4 and Arjun draw. One whit turrets only (and yes, Arjun turret is no longer is it's main part then leo-2A4 turret), and 3 other draws - eacht whit diffrent transparency to better show Arjun or leo-2A4 draw.
You have no point against this, you are unable to made eny even simmilar to this draw, you have no point and not right (true) in this discussion
You faild again.


And when is ending armour after main sight is clearly visible on Arjun Mk.I interior pictures. It's before gunner head. Again - you faild

 

[ersakthivel]

two dimension visible from Arjun draw and eight on Leo-2A4 factory draw is indeed "no dimensions"


You have four draws whit compare Leo-2A4 and Arjun draw. One whit turrets only (and yes, Arjun turret is no longer is it's main part then leo-2A4 turret), and 3 other draws - eacht whit diffrent transparency to better show Arjun or leo-2A4 draw.
You have no point against this, you are unable to made eny even simmilar to this draw, you have no point and not right (true) in this discussion
You faild again.


And when is ending armour after main sight is clearly visible on Arjun Mk.I interior pictures. It's before gunner head. Again - you faild

Look carefully at the composite armor cavity for LEO in the pic below

If we take the crew hole dia to be around 500 mm, then the cavity for composite armor behind the rectangular opening for roof top vision block is just 60 or 70 mm in comparison,

You have posted already that the the LOS for this section in LEO is 640 mm. If all dimensions being same between LEO and Arjun turret then if we deduct the 60 mm from 640 mm we get 580 mm.

So LOS behind main sight for Arjun must be minimum 580 mm even if there is no extra armor block after the roof top vision block,

You cannot deny this Ok?

So if we

The distance between the front tip of the turret and the end of roof top vision block is is written as 1230 mm by you,

Post in your own words what is the same distance in Arjun ? It is about 1300 mm plus if I am correct,

Since LEO has only another additional 60 or 70 mm gap,

in armor cavity for LOS behind this roof top vision block if we deduct this 60 mm from 640 mm we can get 580 mm minimum ,

I think you can not refute this estimate in any way ,Isn't it?

 

[ersakthivel]

take a good look at the first picture,

You draw one red vertical line marking the left hand side edge of the gunner seat,

Then why didn't you draw another vertical line upwards bordering the right hand side edge of the gunner's seat?

Inconvenient perhaps?

The reason may be if you would have done that it would have clearly shown the gunner's head to be NOT RIGHT BEHIND THE MAIN SIGHT AS YOU FALSELY CLAIMED,BUT IN THE SPACE BETWEEN MAIN SIGHT AND THE GUN COVERING PLATE AS i CLAIMED

 

[Dejawolf]

take a good look at the first picture,

You draw one red vertical line marking the left hand side edge of the gunner seat,

Then why didn't you draw another vertical line upwards bordering the right hand side edge of the gunner's seat?

Inconvenient perhaps?

The reason may be if you would have done that it would have clearly shown the gunner's head to be NOT RIGHT BEHIND THE MAIN SIGHT AS YOU FALSELY CLAIMED,BUT IN THE SPACE BETWEEN MAIN SIGHT AND THE GUN COVERING PLATE AS i CLAIMED

DRDO went for hardened steel with high thickness efficiency instead of composites with high weight efficiency. to us experts, it says only one thing.
thickness behind sight is insufficient, so materials with high TE and low weight efficiency must be used instead, to maintain uniform front turret protection.

 

[ersakthivel]

DRDO went for hardened steel with high thickness efficiency instead of composites with high weight efficiency. to us experts, it says only one thing.
thickness behind sight is insufficient, so materials with high TE and low weight efficiency must be used instead, to maintain uniform front turret protection.

your answer has nothing to do with the bolded parts in the quote.

It is obvious main sight cutaway will reduce the LOS behind main sight, so this area will be vulnerable

But what is more important is this vulnerable area is so small i.e it's dimensions must be around 25 cms x 40 cms .

So CVRDE while providing composite armor all around the front turret , decided to go with equivalent higher metallurgy steel for this close to 500 to 600 mm area,

And then after the army request added a down hanging white slab like column to bolster it even further to make it as per the GSQR requirement because ARJUN was developed , modified and further developed only according to Army GSQR and not according to the whims and fancies of the CVRDE

In the picture below we can see the downward hanging white armor slab above the orange dial box ,

On the side of this white block a thin red strip like metal is sticking out and we can see the rest of the roof at a higher level(the darkened area to the top and right side of the white block).

The red strip itself indicates the difference in height in arjun roof level coupled with 200 mm below the roof level opening of the roof top vision block light i and above the gunner's eyepiece.

If only experts can shed some light on what this white block above the yellow or orange dial box and why it is there behind the inside turret front wall exactly behind the main sight

and where the white rectangular box with blue optics is mounted

it will be of great help.

Because it is plain and clear that this blue optic like stuff is fixed on the side of the white column not the roof,

and we can even clearly see the grease mark like stain originating from the red metal stripe and coming towards the blue optic box,

Surely the black stain like line is not hanging in the air and the blue optic like stuff on the white rectangular box is not mounted on the roof,

So inconveniently for the tank experts this white block is just behind the main sight weak area, So is there any possiblity it is another storage box with heat retaining features where the crew store their hot food to remain fresh?

I hardly believe so. I don't think the CVRDE will be that kind to the crew men.They already have provided huge storage boxes on the side for that.

So why is tank expert community so reticent in explaining the above features, I am raising these points the hundredth times in this thread and Arjun Vs T-90 thread,

But every time the stock reply is "I am seeing phantoms where none exists", which is no expert speak at all.

 

[Dejawolf]

It is obvious main sight cutaway will reduce the LOS behind main sight, so this area will be vulnerable

But what is more important is this vulnerable area is so small i.e it's dimensions must be around 63x46cm.

So CVRDE while providing composite armor on front and sides of turret , decided to go with high-hardness steel for this close to 300-350mm thick area.

corrected your statement. also, if this area has hardened steel instead of composites, it's not a weakspot, but instead has similar protection to the rest of the turret.

also provide sources for your claims about the "down hanging white slab like column".

 

[ersakthivel]

corrected your statement. also, if this area has hardened steel instead of composites, it's not a weakspot, but instead has similar protection to the rest of the turret.

also provide sources for your claims about the "down hanging white slab like column".

See the post 5611 above, what more proof am I expected to provide?

 

[Dejawolf]

See the post 5611 above, what more proof am I expected to provide?

LOL. "it is true because i say so" is not valid proof. and just up until a few days ago, you were arguing that the armour block was stretching all into the bustle of the turret or something. and the arjun has armour frontal armour that can withstand being punched by chuck norris, all in the lithe package of 58 tons.

besides there's ample evidence that no armour block exists. just take those pictures from bluemango films as an example.

 

[ersakthivel]

LOL. "it is true because i say so" is not valid proof. and just up until a few days ago, you were arguing that the armour block was stretching all into the bustle of the turret or something. and the arjun has armour frontal armour that can withstand being punched by chuck norris, all in the lithe package of 58 tons.

besides there's ample evidence that no armour block exists. just take those pictures from bluemango films as an example.

On the contrary those three things the white block, blue optic, red strip exist in BLUE Mango film screen shot and not in the india today -1990 pictures of gunner eye piece mock up you believe is true.

typing four useless lines while unable to answer where the blue optic white box ans red strip and black stain are placed , on which plane they are
does not mean they are not there,

Isn't it?

So when you make models with your 10 experience you will leave out whatever stuff you cannot explain, Thats what you are saying,

That holds good for video games not models for technical studies,

In technical scale based model , each item must be placed on their proper plane,

You are not putting the white block on which these three items exist doesnot mean they and the plane on which they are placed is not there,

It only means your model is not representative of the true Arjun tank and based on 1990s India today pictures that have nothing to do with even today's prototype Arjun, let alone production Arjun.

 

[Dejawolf]

On the contrary those three things the white block, blue optic, red strip exist in BLUE Mango film screen shot and not in the india today -1990 pictures of gunner eye piece mock up you believe is true.

LOL. typing four useless lines while unable to answer where the blue optic white box ans red strip and black stain are placed , on which plane they are
does not mean they are not there,

Isn't it?

So when you make models with your 10 experience you will leave out whatever stuff you cannot explain, Thats what you are saying,

That holds good for video games not models for technical studies,

In technical scale based model , each item must be placed on their proper plane,

You are not putting the white block on which these three items exist doesnot mean they and the plane on which they are placed is not there,

It only means your model is not representative of the true Arjun tank and based on 1990s India today pictures that have nothing to do with even today's prototype Arjun, let alone production Arjun.

i was talking about your magic armour block.
i just can't see it:

 

[ersakthivel]

i was talking about your magic armour block.
i just can't see it:

Show me the 4 bolts in the picture above in the same exact place as Dejawolf has put,

in any actual operating Arjun tank inside photo,

All four bolts must be in the same place is what counts,

one bolt that is visible is far way from where you have put it.

Why?

If the actual arrangement is like this , we can not see the roof top vision block in any photos, as it shows up in the photo below,

The roof top vision vision block shows up below the orange box in the photo below,

That too at the same height as that of the bottom of the vision blocks over Tc's seat. More than 200 mm below the ceiling of the inside turret roof.

It can never happen if the arrangement is as as shown in the photo

In the photo above the camera should have been held at the chest level of the Tc. So there is no way that the roof top vision block can show up below the orange box.It is impossible.

And also if you observe the roof top vision block closely , you can see the opening for light is NOT cut out in the horizontal inside roof top turret, But it looks like a rectangular opening cut out of a slanting plane on the white block behind it.

Also with this model you can never explain the folded bumps and their purpose on the wall of the white armor block on which the main vision block with binocular gunner's eye piece is mounted,

These folds indicate that the armor block behind the main sight is not flat as you repeatedly call for and the thickness varies to compensate for the cutaway for the main sight.

A huge gap is shown between the back side wall of the white armor block on which the main vision block with binocular gunner's eye piece is mounted and the turret inside front armor wall,

But as per the photo above this back side wall of the white armor block on which the main vision block with binocular gunner's eye piece is mounted directly on the armored column,

And this armored column ends at a distance of more than 1300 mm behind the front tip of the turret gun covering plate.

Even you have accepted it.

So if you deduct the 1300 mm from the 2500 mm pivot base point we get 1200 mm ,

If we deduct 700 mm depth taken away by the hatch cover cutaway from this 1200 mm , A minimum 500 mm still stands even if we accept your argument that the armor wall behind the main sight is flat.

In real life the whole cylindrical pipe shown in grey colr is inside the armor block and there is no air gap between the back wall of the white main vision block with binocular gunner's eye piece and the turret armor back plate.

So if the roof top vision block is cut behind the slanting orange box with bolts and that too at the same height as the bolts , it can never show up in the photo above.

So if the roof top vision block is cut behind the slanting orange box with bolts ,

and that too at the same height as the bolts , it can never show up in the photo below.

and that too below the bottom of the slanting orange box.

Also with this model you can never explain the folded bumps and their purpose on the wall of the white armor block on which the main vision block with binocular gunner's eye piece is mounted, as shown in the photo below,


These folds indicate that the armor block behind the main sight is not flat as you repeatedly call for and the thickness varies to compensate for the cutaway for the main sight.

A huge gap is shown between the back side wall of the white armor block on which the main vision block with binocular gunner's eye piece is mounted and the turret inside front armor wall,

But as per the photo above this back side wall of the white armor block on which the main vision block with binocular gunner's eye piece is mounted directly on the armored column,

And this armored column ends at a distance of more than 1300 mm behind the front tip of the turret gun covering plate.

Even you have accepted it. and gave 600 + 600 mm in your distances for A, B, C, D discussion, for C and D

So it is crystal clear that the armor back plate is at 1300 .

So if you deduct the 1300 mm from the 2500 mm pivot base point (includes the gun cover plate)we get 1200 mm ,

If we deduct 700 mm depth taken away by the hatch cover cutaway from this 1200 mm , A minimum 500 mm still stands even if we accept your argument that the armor wall behind the main sight is flat.

But it is not flat as the bumpy folds on the armor back plate shows,

From now on place all your posts regarding the Arjun models and armor LOS here in this thread as adviced by PMAITRA,

I have to agree with this.

@ersakthivel, it is true that DRDO is doing its best, yet, since we do have a non-uniform front protection, it is important to focus on that vision cutout in the front turret that seems like an Achilles Heel of the Arjun Mark II.

The bumpy folds in the armor backside indicates the design intent to give more LOS behind the main sight to compensate for the main sight cutaway.

Which can not be explained by any other way,

BTW, we have a thread for Arjun Mark II, so let's debate it in the correct thread.

because none of these discussions have anything to do with Arjun MK-2 as of today as no one has sen the insides of it.

And the final design has not even been freezed.

 

[ersakthivel]

i was talking about your magic armour block.
i just can't see it:

well you have placed a rectangular pipe to bring down the light from the roof top vision block in a vertical position in the photo above, (besides the obvious error of placing the slanting orange box and the gunner head at 300 mm above where they actually should be)

Any photo proof for this pipe?

The the armor back plate is behind the white gunner's main sigh box (with binocular like eyepieces ) is at 1300 mm behind the front turret tip (including gun covering plate) . So that itself gives a minimum LOS of 500 mm , even if you deduct the main sight cut away depth of 700 plus mm.

You have given the values as 760+300 +600+600 for my A, B,C,D dimensions.

So as per your dimensions the armor back plate behind the main sight is 1200 mm infront of the base pivot for the hatch cover
(which is 2500 mm behind the turret front tip including the gun cover plate in the only dimensioned scale Br drawing posted here.).

So 2500mm -1200 mm=1300 mm

from this 1300 mm if we deduct the 700 plus mm for the main sight cut away we get a minimum of 500 plus mm for LOS behind the main sight as I am saying repeatedly. And as shown by my comparison with LEO-2.

this side view below is wrong as well, with respect to the gunner's head height.

Tc's seat height and head height is wrong as well.

you have shown the Tc's chin in line with the bottom of the vision block .

but in reality it is the Tc's forehead that is in line with the bottom of the vision block,

Which shows either the height of your tc and gunner set is wrong,

or,

the human models in your 3d model are disproportionately sized , just like the gun size near the Gunner.

 

[ersakthivel]

i was talking about your magic armour block.
i just can't see it:

one of your admirers has also give the distance of the roof top vision block as 1330 mm from the turret tip including gun covering plate I suppose.

But his 815 mm and 315 mm distance marking willnot apply to the tank turret in production below,

In the picture above , In the same way the ratio of [ distance from front tip of the turret(excluding the gun cover plate) to the pivot base of the hatch cover ] / [ distance from tip of the turret (excluding the gun cover plate) to for hatch cutaway ] is 3.14 .

In the image below distance from front tip of the turret(excluding the gun cover plate) to the pivot base of the hatch cover is 2250

so 2250 / 3.14 = 716 mm is the gap for the hatch cutaway.

well if the gun swivels flat horizontal it's covering plate will be in line with the turret tip of the main sight cutaway,

So we can pretty much discard the excluding the gun cover plate assumption as it may not make any material difference and straight away say the hatch cutaway depth is 700 odd mm.

So if we read it with the previous post it is now confirmed that the armor back plate is 600 mm behind the back wall of the min sight cutaway so even if the armor back plate is straight and flat an LOS of 600 mm is minimum, You won't have any problems with it i think.

 

[Dejawolf]

well you have placed a rectangular pipe to bring down the light from the roof top vision block in a vertical position in the photo above, (besides the obvious error of placing the slanting orange box and the gunner head at 300 mm above where they actually should be)

Any photo proof for this pipe?

none, which is why i changed it a few months back:

The the armor back plate is behind the white gunner's main sigh box (with binocular like eyepieces ) is at 1300 mm behind the front turret tip (including gun covering plate) . So that itself gives a minimum LOS of 500 mm , even if you deduct the main sight cut away depth of 700 plus mm.

the eyepieces are likely monocular, with one for daysight, and one for thermal.

You have given the values as 760+300 +600+600 for my A, B,C,D dimensions.

So as per your dimensions the armor back plate behind the main sight is 1200 mm infront of the base pivot for the hatch cover

correct

(which is 2500 mm behind the turret front tip including the gun cover plate in the only dimensioned scale Br drawing posted here.).

incorrect. 2260mm.

this side view below is wrong as well, with respect to the gunner's head height.
Tc's seat height and head height is wrong as well.

it has been corrected, and has no impact on the front armour thickness.

Which shows either the height of your tc and gunner set is wrong,
or,
the human models in your 3d model are disproportionately sized , just like the gun size near the Gunner.

it was the seat height.

anyways, this is typical ershaktivel argument tactics.
bring up an argument. pick on things that have no impact on this argument.
claim victory.

 

[ersakthivel]

none, which is why i changed it a few months back:

it was the seat height.

anyways, this is typical ershaktivel argument tactics.
bring up an argument. pick on things that have no impact on this argument.
claim victory.

incorrect. 2260mm.

give proof of this 2260 mm mark on the BR line drawing below , and which component in your model lies 2260 mm behind the front tip of the turret including gun covering plate

and on the same BR line drawing mark the position of the roof top vision block in relation to the bar holder,

You have given the values as 760+300 +600+600 for my A, B,C,D dimensions.
So according to you ,

1.this 760 mm is the depth of the main sight cutaway from the front tip of the turret ,
2, 300 mm is the LOS,
3.600 mm is the gunner's space,
4.600 mm is the Tc's space.

Am I right?

Also please state from which point on the front tip of the Arjun turret shall we start measuring the 760 mm,

from the turret tip excluding the cover plate or from the turret tip including the cover plate?

This is vital because my 700+ 600+600+600 =2500 mm break up for the A, B, C, D measurement starts from the tip of the turret including the gun covering plate.

My measurement starts at turret tip at 6.5 meter mark on the BR line drawing above and ends at 4 meter mark right under the pivot base for the hatch closing cover.

The Tc seat head rest is located right below this pivot base for the closing cover of the hatch is my estimate from the photos.