Arjun vs T90 MBT

[ersakthivel]

Sure, it's comparable to M1 from circa 1981-1984, Leopard-2A0 from 1980-1983, and Leclerc prototype from Swedish tank trials.
Im say this very seriously!
Each mentioned tank is about 400-550mm vs APFSDS and about 700-800mm vs HEAT. And that level for Arjun is fully possible.



Becouse there is no other option when we compare 3BM42 and those funny 120mm ammo for Arjun. In fact it's look jak DM23...

What they said is it is comparable to modern MBTs of the world,not 40 year old relics, you can watch the interview on the link again.
those were the older Ammo types like the older lighter turret of tank -ex.
Newer ammo with much better protection levels are being developed is Kunal's statement.


After the sorting out of FCS troubles and heat hardening of electronics,Now only ARJUn's large scale induction looks like a certainity.

So ammo development will gather steam only now.because you cannot spend huge amount of R& D or enter into costly TOT for better ammo with just 124 arjun mk-1s in indian army.

 

[Dejawolf]

First you make grand BLAH BLAH statement that TANK -EX turret is same as ARJUn in weight and armor protection level without an iota of proof.If the other guy expresses a different opinion you will ask proof from him.Such a nice authentic way of debating, so that you can never lose.

If the turret of tank ex and arjun are same in protection level, weight and protection levels why was TANK -EX rejected?

1000/47 = 21.27hp/ton
1400/58.5 = 23.93hp/ton

that's one reason. Arjun has better mobility than tank-ex.
the reliability issues of the 1000hp T-90 engine in hot climates is already known, and tank-ex would not fare much better.
protection is yet another point, T-72 front hull has a maximum protection of about 400mm, while Arjun hull according to my estimates would be about 700mm.
Arjun hull also has heavy composite skirts on the front half of the hull, and armoured mudguards, increasing side and 60 degree off angle protection, which the T-72 lacks.
so there you have 3 good reasons.

 

[Dejawolf]

So as per your estimate the massive difference of 11 plus tons of ARJUN over TANK EX is all there for the heavier engine and no component of it forms better armor.ANy basis?
If that is right then why was TANk-ex rejected?

it is for the heavier engine and transmission, longer hull, extra roadwheels, longer and wider tracks, heavier front hull protection and addition of heavy sideskirts.

 

[kshkumsin]

Don't confuse fact to pass your opinion..

You have completely ignored the distance of the camera from the turret of both tanks, Enlarging one and minimize one and hence they all look same..

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Why you missed this one, Guess you just want to push your view ..



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If you dont like to listen, its your choice..

could u reply to my q on ficv thread please

 

[ersakthivel]

it is for the heavier engine and transmission, longer hull, extra roadwheels, longer and wider tracks, heavier front hull protection and addition of heavy sideskirts.

Ofcourse of the 11 extra tons they would have taken about some specific percent of the weight, in the same way better armor would have taken the remaining percentage of weight.Both you and me don't have the statistics to either refute or support this statement.that is the only reality.

 

[ersakthivel]

could u reply to my q on ficv thread please

You readily gave the weight of tank -ex

if you give the dimensions of tank ex and arjun
and
compare them to the weights of tank-ex and Arjun we can have some discussion.

 

[ersakthivel]

1000/47 = 21.27hp/ton
1400/58.5 = 23.93hp/ton

that's one reason. Arjun has better mobility than tank-ex.
the reliability issues of the 1000hp T-90 engine in hot climates is already known, and tank-ex would not fare much better.
protection is yet another point, T-72 front hull has a maximum protection of about 400mm, while Arjun hull according to my estimates would be about 700mm.
Arjun hull also has heavy composite skirts on the front half of the hull, and armoured mudguards, increasing side and 60 degree off angle protection, which the T-72 lacks.
so there you have 3 good reasons.

Can you give the exact weight of both the engines, so that we can compare how much weight per HP is added in arjun vis a vis TANk -ex?

 

[Dejawolf]

Can you give the exact weight of both the engines, so that we can compare how much weight per HP is added in arjun vis a vis TANk -ex?

sure,
MTU MB 838 ka-501 with renk RK 304S:
2000kg+2300kg = 4300kg
V-84MS with transmission:
1050kg+700+710+310kg = 2770kg

so MTU powerpack is 1 ton heavier.

 

[ersakthivel]

sure,
MTU MB 838 ka-501 with renk RK 304S:
2000kg+2300kg = 4300kg
V-84MS with transmission:
1050kg+700+710+310kg = 2770kg

so MTU powerpack is 1 ton heavier.

So where will be the the remaining 10 tons on ARJUn's structure? With some source for checking the validity of assumptions.

 

[ersakthivel]

What is the distance (in the width axis of arjun's turret )between the gunner's seat and TC's seat in this photograph?

it seems gunner an TC almost sit inline along the hull length axis.is it correct?

 

[Dejawolf]

Ofcourse of the 11 extra tons they would have taken about some specific percent of the weight, in the same way better armor would have taken the remaining percentage of weight.Both you and me don't have the statistics to either refute or support this statement.that is the only reality.

you don't, i do.
to be gentle, i used Pmaitra's drawing, with hull length of 8m, instead of your estimate of 10m for the hull.
then i compared the side profile of T-72, i can arrive at the surface area increase in the side profile. then i multiply this surface area with 80mm thickness, and also take into consideration hull roof and floor addition.
the volume came to about 148639cc for the side hull
((148639*7.85)/1000)*2 = 2333kg
and 81758cc for the roof and floor with 20mm thickness
(81758*7.85)/1000 = 641.8kg
for sideskirts, i used Pmaitra's drawing again:
(146746*7.85)/1000 = 1151kg
composites
(89749*3.65)/1000 = 327.584kg
and finally both skirts together
(1151+327.)*2 = 2956kg
weight of a roadwheel with torsion bar on a T-72 is 197kg. let's assume a similar weight for Arjun.
197*2 = ~400kg

a single track on a T-72 weights 1780kg
T-72 track volume is about 608300cc while arjun track volume is about 825600cc
assuming similar density:
825.6/608.3 = 1.35723
1780*1.35723 = 2415kg.
2415-1780 = 635kg

now there's a few other things that i've left out, the extra length of the skirts and track guards. quick estimate came to about 46kg for one skirt,
so 93kg for both. and the armoured mudflaps, about 300kg for each

so let's review:
2333+641+2956+400+635+1000+93+600 = 8652kg

now there's a few other changes i haven't taken into consideration, like whether the Arjun suspension is heavier than the T-72 suspension. and how much weight the additional real hull assembly adds, but MEH.

so that leaves about 2.4 tons or less for the increased protection of the front hull armour.

 

[ersakthivel]

If we view these pictures the gun mantlet almost covers half of the crew hatch holes from the front.

So the red box you scribled before the tank commander may be actually situated behind the mantlet and not behind the cutaway in the turret left for gunner's main sight is my guess.Since gunners seat is vacant it seems to be in front of the TC .

See the man is holding communication set in his left hand .the left portion of his body is behind the gun mantlet .

The right portion of his body is the one behind the cutaway section in the turret front provided for gunner's main sight, which is situated well behind the red box you scribled.

So the red box you scribbled is directly in front of the man sitting right behind the gun barrel in the vacant seat and not before the man in the picture.

care to explain?

if the gunner and TC are sitting almost in line then all your 3D max drawings for arriving at the thickness of side armor and turrent frontal armor are all dead wrong.

 

[Dejawolf]

Sorry but this is overestimated...

The result is circa that:
In my personal opinion T-90A basick armour (without hevy ERA) is about:
for 840mm LOS about ~650mm RHA
for 650mm LOS about ~500mm RHA.

Of course in my opinnion russian havy ERA works on more sophisticated way, and you can not count it like "base armour" x1,5 etc., bt for the other hand -modern western APFSDS penetrator haven't probem whit russian ERA...

these values ARE for 840mm LOS. and if you peek just below the heavy ERA, you will see that my 840mm LOS values are actually lower than yours, ~610mm vs KE.
as for the ERA protection: i'll refer you to these documents:
http://www.dejawolf.com/armorscience/armor.x.ijie.vol_unk_pp_unk.protection_performance_of_dual_flying_oblique_plates_against_a_yawed_long_rod_penetrator.paik_kim_yoo_lee.2006.pdf
http://www.dejawolf.com/armorscience/bulgingplates.pdf

in the first document, it's said that penetrator length is reduced by about 15% and speed by about 3% when ERA is at a 60 degree angle. and penetrator moving at 1.5m/s

in odematt let's take a penetrator with rod length of about 750mm diameter of 25mm and V0 of 1650m/s
if it is DU, that gives a penetration of ~830mm
after being broken up by the ERA,
750*0.85 = 637mm
1650*0.97 = 1600m/s
running it through odematt again, this time penetration is reduced to 705mm so the ERA provided by itself around 125mm vs KE. + 80mm steel for the container, and a little extra for penetrator yaw and spacing, and 250mm vs KE seems fairly realistic.

 

[ersakthivel]

Please illustrate the positon of the seat for man behind the gun barrel(the gunner) strictly according to the picture you posted below.

 

[Austin]

DRDO Developed APFSDS displayed at recent exhibition Source

125 mm http://3.bp.blogspot.com/-tH-9R-hYM4Q/UOqQwSfqh7I/AAAAAAAADGs/_hBzjmym25E/s1600/125mm+APFSDS.JPG
120 mm http://4.bp.blogspot.com/-6ld1HWhDDW8/UOqQr3aYO6I/AAAAAAAADGk/VkLG5mxWRmI/s1600/120mm+APFSDS.JPG

 

[Dejawolf]

So the red box you scribled before the tank commander may be actually situated behind the mantlet and not behind the cutaway in the turret left for gunner's main sight is my guess.Since gunners seat is vacant it seems to be in front of the TC .

i don't get it. what's your point? are you suggesting the turret is even thinner behind the GPS than you originally assumed? if so, yes that's a possibility.

 

[Dejawolf]

Please illustrate the positon of the seat for man behind the gun barrel(the gunner) strictly according to the picture you posted below.

gunner is red, TC is green.

 

[ersakthivel]

gunner is red, TC is green.

So according to you this is the original seating arrangement of arjun.Isn't it?WRONG

then why this following schematic diagram of arjun looks so different from yours?
the drawing below places the man sitting right behind the gun in the middle of the tank, between the other two members of the crew.
But your drawing fixes him to the extreme left.Which one is right?
So which is the right one?

 

[ersakthivel]

@Dejawolf, @Damian
See the width of gun mantlet is 1140 mm.
1.the first crew member you have drawn in red in the post above is sitting right behind the1140 mm width maingun plate.
2.The other two crew members sit behind him.
So all the three seats of the crew are situated within 250+1140 +250=1640 mm width .
That is from a line drawn through the center of the main gun barrel all three seats are situated within 820 mm to the left side and 820 mm to the right side according to the schematic drawing.

So if you add another 400 mm of elbow room for the crew members who sit right under the crew hatch,
2X400mm =800 mm+1640 mm=2440mm is supposed to be the width of the crew compartment(bordered by side wall armor mounting painted in white in the photo ) in the hull.
The total arjun turret width measured from outside is 3280 mm.

So 3280-2440mm=840 mm of space is the total available space available for armor on both sides of the arjun turret.each side has 420 mm(including the storage boxes)

So for the frontal turret armor KUNAl's estimate of 1000+ mm LOS thickness is also correct.
Side turret armor should have atleast 420 mm LOS thickness at least till the crew hatch .
After the middle or end of the crew hatch storage boxes reduce this width to armor space to LOS thickness of 300 plus mm is my estimate.

this is my estimate based on the schema of original arjun drawing..

So arjun having composite armor placement all around seems right,please post your clarification.

 

[Damian]

Other than russsia which builds

smaller three men crew truncated turret tanks,
which rely on turret geometry ,
and unsafe storage of ammo ,
following the world war II philosophy of cheaper lesser weight more in number tanks according to the T-series philosophy ,

every other major tank producing country has,
near 60 ton four men crew well protected,
safe ammo storage tanks .

So weight does have meaning of overall protection level of the tank ,if you take everything into account like,
safe ammo storage,
heavier armor all around(instead of relying on obsolete statistics from lesser accurate lesser range FCS guns of world war two tanks) ,
costlier tanks that guaranties crew safety.

Why heavier tanks with much more internal volume are being built by some western nations,if 3 men crew , auto loader based lesser weight tanks can give the same level of protection and safe ammo storage of upto 45 rounds inside the hull?

They sat 4 men crew results in lesser fatigued crew which results in higher morale troops using better protected safer ammo storage tanks has a decisive implication in long drawn battle battles.

There are two different tank design schools out there.both are churning out products, Each school believes their design principles are better.

Funny thing, but I actually talked with people that were NATO tanks crews members, and they are far more realistic than you, and have much greater respect to T tanks. This is enough for a comment.