Arjun Main Battle Tank (MBT)

[methos]

I don't see how Leopard 2 can have more armour than Arjun behind the main sight, for Leo 2A4. The sight is positioned much more to the inside than on the Arjun.

This might be true, but in the Leopard 2 the gunner is sitting below the armour cavity (dejawolf posted a nice photograph showing that some time ago), which is located behind the gunner's main sight. On the Arjun this armour cavity is not present:

As one can see, the place above the gunner's head is not occupied by an armour block.

Edit:
Compare with this:

Any thoughts on the above Singaporean Leo 2A4 picture? The main sight seems to be positioned much more inside than in Ex-Bundeswehr Leo 2A4.

It is not a Singaporean one. The picture shows the Leopard 2 Evolution, an armour upgrade made by the German company IBD Deisenroth Engineering. Singapore bought several armour kits from them, but they look slightly different (more shaped like a box).
The sight is not positioned deeper inside, the turret armour was only thickened by adding further armour modules, since they cannot put an armour block in front of the main sight (without moving the main sight, and this is something a company specialized on producing armour doesn't do) the distance from the outermost armour layer and the sight has increased.

This image pretty much shows everything (Singaporean Leopard 2 with applique armour and the difference in armour thickness):

Also, is Arjun's turret armour cavity smaller than Leo 2A4's?

Over the turret front it seems to be pretty comparable by my estimates and those from dejawolf and militarysta. At the mantlet, the gunner's sight and the sides it seems however to be smaller.

 

[The Last Stand]

This might be true, but in the Leopard 2 the gunner is sitting below the armour cavity (dejawolf posted a nice photograph showing that some time ago), which is located behind the gunner's main sight. On the Arjun this armour cavity is not present:

As one can see, the place above the gunner's head is not occupied by an armour block.

Okay, as per my understanding, There is an armour block after the main sight in Leo 2 and the gunner sits below the main sight weakspot, and is safe behind a block of armour.

It is not a Singaporean one. The picture shows the Leopard 2 Evolution, an armour upgrade made by the German company IBD Deisenroth Engineering. Singapore bought several armour kits from them, but they look slightly different (more shaped like a box).
The sight is not positioned deeper inside, the turret armour was only thickened by adding further armour modules, since they cannot put an armour block in front of the main sight (without moving the main sight, and this is something a company specialized on producing armour doesn't do) the distance from the outermost armour layer and the sight has increased.

This image pretty much shows everything (Singaporean Leopard 2 with applique armour and the difference in armour thickness):

Thanks, but was armour added behind the sight, or is that even possible. Oh and by the way, Leo 2 evolution looks like a monster compared to the older tank :scared:

Over the turret front it seems to be pretty comparable by my estimates and those from dejawolf and militarysta. At the mantlet, the gunner's sight and the sides it seems however to be smaller.

AFAIK Mantlets are usually more thickly armoured than the turret front, but militarysta stated these as weakspots for most tanks.
Gunner's sight, no arguing. Pictures speak a thousand words

For sides, what is your estimate? ~50-75 mm less than Leopard 2 or more than that?

when I get information freely like this.

 

[methos]

Okay, as per my understanding, There is an armour block after the main sight in Leo 2 and the gunner sits below the main sight weakspot, and is safe behind a block of armour.

I edited my post while you were writing, just look at the photograph of the Leopard 2 turret interior. The gunner's sight is covering (slightly less than) the upper half of the turret front. There a thick armour block is located.
Below that armour block - and behind the turret front armour with normal thickness - is the location of the gunner.

Thanks, but was armour added behind the sight, or is that even possible.

There is not much place behind the older armour block. To be more exact: On the old Leopard 2 tanks with the original PERI R17 A1 commander's sight, the armour blocks end directly in front of it.

It is impossible to put more armour behind there. The Leopard 2A5 and other upgraded versions have the PERI R17 moved to a different location, but there the gunner's main sight was raised, so that there is no need to put more armour behind it.

On the Leopard 2 Evolution, they probably exchanged the armour against newer (maybe heavier) one at this place, but it still should be a weak spot. RUAG has designed an upgrade which add slat armour in front of the main sight, depending on the distance between the bars it could have at least some effect on APFSDS ammunition.

AFAIK Mantlets are usually more thickly armoured than the turret front, but militarysta stated these as weakspots for most tanks.

No, on modern tank's mantlets are weak spots. The Leopard 2 has ~40 cm mantlet armour (behind the armour block is still the gun mount with ~20 to 24 cm homogenous steel), while the turret front is ~84 cm thick. The M1 Abrams doesn't even have composite armour in the mantlet. The Challenger 1 & 2 MBTs were made with a special design with no gun mantlet, but this causes a lot of maintenance trouble (exchanging the gun barrel might take up to 1 day instead of 30 minutes for other tanks).
There are several different factors determining the size and weight of a mantlet. A mantlet does need to be wide enough to contain the gun, the gunner's reserve sight and the coaxial MG port, but at the same time it cannot weigh too much, because else it would imbalance the gun and make the stabilization less effective. Also the space available is pretty much limiting the amount of armour there.

For sides, what is your estimate? ~50-75 mm less than Leopard 2 or more than that?

In the frontal area, the side armour seems to be roughly equal (max. difference should be less than ~10%), but that's only 1/3 of the turret side. The rest of the flanks is not covered by composite armour on the current Arjun tanks, there the Leopard 2 has much thicker and more potent armour.

 

[The Last Stand]

No, on modern tank's mantlets are weak spots. The Leopard 2 has ~40 cm mantlet armour (behind the armour block is still the gun mount with ~20 to 24 cm homogenous steel), while the turret front is ~84 cm thick. The M1 Abrams doesn't even have composite armour in the mantlet. The Challenger 1 & 2 MBTs were made with a special design with no gun mantlet, but this causes a lot of maintenance trouble (exchanging the gun barrel might take up to 1 day instead of 30 minutes for other tanks).

There are several different factors determining the size and weight of a mantlet. A mantlet does need to be wide enough to contain the gun, the gunner's reserve sight and the coaxial MG port, but at the same time it cannot weigh too much, because else it would imbalance the gun and make the stabilization less effective. Also the space available is pretty much limiting the amount of armour there.

In the frontal area, the side armour seems to be roughly equal (max. difference should be less than ~10%), but that's only 1/3 of the turret side. The rest of the flanks is not covered by composite armour on the current Arjun tanks, there the Leopard 2 has much thicker and more potent armour.

Thanks methos, is there any way to uparmour mantlets to reduce the weakspot?

And is it possible to remove storage boxes altogether and add ~300+ mm RHAe Composite armour to the Arjun side turret. Also, how much would Arjun's side hull rate against KE?

 

[Damian]

is there any way to uparmour mantlets to reduce the weakspot?

Yes but can be problematic, as Methos pointed out.

And is it possible to remove storage boxes altogether and add ~300+ mm RHAe Composite armour to the Arjun side turret.

It is possible, and should be relatively simple operation.

Also, how much would Arjun's side hull rate against KE?

Same as in any modern tank, side hull thickness in modern tanks range from 20mm to 80mm depending on place and tank we discuss, and is made from homogeneus steel armor.

Protection here can be improved by adding side skirts of various types, ERA etc.

The M1 Abrams doesn't even have composite armour in the mantlet.

We don't know this, the mantled shield is thick enough to have sort of spaced or composite protection.

The Challenger 1 & 2 MBTs were made with a special design with no gun mantlet,

Wrong, the Chieftain and Challenger 1 do not have gun mantle (the latter because it have a turret based on Chieftain turret, just slightly redesigned and covered with composite armor), while Challenger 2 have gun mantled.

 

[methos]

is there any way to uparmour mantlets to reduce the weakspot?

On all modern tanks the mantlet is less armoured than the turret front, but it can be improved to be "less worse". How exactly depends on the tank and it's design. As said earlier, the M1 Abrams does not some to have composite armour at the mantlet, but it the mantlet covers a smaller area than that of the original Leopard 2. It still can/could be uparmoured by welding steel plates on the front (which was done iirc. during Operation Desert Storm sometimes).
During the upgrade from Leopard 2A4 to Leopard 2A5 the mantlet is exchanged with a different design, which is much smaller, but thicker. At the places which were earlier covered by the mantlet, new armour modules are fitted. But as far as I know this redesign was only possible, because the Leopard 2A5 is using a modified gun mount with different stabilization, elevation and recoil mechanism.

And is it possible to remove storage boxes altogether and add ~300+ mm RHAe Composite armour to the Arjun side turret.

It is possible to redesign the tank. But just removing the boxes and putting armour modules there is not really possible, because of two reasons:
1.) The equipment previously stored in the storage boxes needs to be stored somewhere else
2.) The storage boxes are currently fitted with four rather small bolts each. I don't think that this would support the weight of a thick Kanchan armour array.

Also, how much would Arjun's side hull rate against KE?

The hull side of all tank's is rather weakly protected. The hull sides and the hull rear are the places of a tank, which are the least likely hit. Soviet tanks have 80 mm thick armour (RHA) along the whole hull sides, while Western tanks seem to have a "steplike" side armour layout - the frontal side armour is probably ~80 - 100 mm thick, while it get's thinner at the rear. In case of the CATTB prototype (which used a modified M1 Abrams hull) the engine compartment was protected by 1.5 inch thick RHA (~38 mm), the Leopard 2 is said to also have some ~40 mm armour at the engine comparment.
Together to the basic hull side armour, modern tanks are often fitted with side skirts made, whose design is depending on the tank layout. The M1 Abrams for example has ~70 mm thick ballistic skirts, while the Leopard 2 has 150 mm thick ones. The difference in thickness is the result of the different interior layout: The M1 Abrams has very long fuel tanks in the frontal hull, thus the ballistic side skirts are very long (covering between 1/2 and a 1/3 of the M1's side). The Leopard 2 on the other hand stores main gun ammunition in the frontal hull, so the armoured skirts are thicker, but shorter (covering less than a third of the vehicle's hull side).

The Arjun has probably similar thick hull side armour, while the side skirts are definetly longer than that of the Leopard 2, simply because the Arjun stores both ammunition and fuel in the frontal hull. Kunal Biswas posted some time ago the following image:

We don't know this, the mantled shield is thick enough to have sort of spaced or composite protection.

There is a picture of one M1 Abrams' mantlet not attached to the gun. It seems to be cast steel mainly, not really containing enough space for any noteworthy composite filler.

Wrong, the Chieftain and Challenger 1 do not have gun mantle (the latter because it have a turret based on Chieftain turret, just slightly redesigned and covered with composite armor), while Challenger 2 have gun mantled

You are right, I meant the Chieftain and the Challenger 1. I typed in the wrong name...

 

[Damian]

There is a picture of one M1 Abrams' mantlet not attached to the gun. It seems to be cast steel mainly, not really containing enough space for any noteworthy composite filler.

It might be a cast steel, but does not mean there is nothing inside, it might be a spaced armor, perhaps it contain something else, who knows.

It is possible to redesign the tank. But just removing the boxes and putting armour modules there is not really possible, because of two reasons:
1.) The equipment previously stored in the storage boxes needs to be stored somewhere else
2.) The storage boxes are currently fitted with four rather small bolts each. I don't think that this would support the weight of a thick Kanchan armour array.

This is not a big problem. You just take out these storage boxes, clean the area from any bolts and attachements, prepare it, weld on plates to create box for composite filler and voila, storage boxes can be then installed in the same place over composite armor cavities, it will not look elegant, but should work.

 

[The Last Stand]

It is possible to redesign the tank. But just removing the boxes and putting armour modules there is not really possible, because of two reasons:
1.) The equipment previously stored in the storage boxes needs to be stored somewhere else
2.) The storage boxes are currently fitted with four rather small bolts each. I don't think that this would support the weight of a thick Kanchan armour array.

1) Turret basket, perhaps or a storage box attached to turret bustle?
2) Welding?

 

[Kunal Biswas]

This topic was debated before..

------------------------

http://www.ibd-deisenroth-engineering.de/news.html

-----------------------

Such an upgrade can be done with help of many foreign firms with DRDO..

But its not official..

1) Turret basket, perhaps or a storage box attached to turret bustle?
2) Welding?

 

[methos]

It might be a cast steel, but does not mean there is nothing inside, it might be a spaced armor, perhaps it contain something else, who knows.

It does not seem like spaced armour; on th picture large parts of the right side are missing, there is no sign of any space or composite filler.

This is not a big problem. You just take out these storage boxes, clean the area from any bolts and attachements, prepare it, weld on plates to create box for composite filler and voila, storage boxes can be then installed in the same place over composite armor cavities, it will not look elegant, but should work.

This means that you need to take all tanks to the factory again, unload them completely and then weld the cavity on every single tank. This is from my perspective a more extensive rebuild, given that it takes a lot of time, space and money to do so (just moving all tanks back to the factory is going to be very expensive).
If the Indian government decided to do so, they also should change the location of the main sight and reduce the size of the gun mantlet... or instead just make a new turret, that would be easier.

1) Turret basket, perhaps or a storage box attached to turret bustle?

It depends on what exactly is stored in the turret bustle and what in the side storage boxes. The Arjun's turret bustle is already longer than the turret bustle of the Leopard 2A5 and the M1 Abrams. Depending on the weight/weight distribution it might have negative effects to the tank (like an imbalanced turret).

 

[militarysta]

Okay, as per my understanding, There is an armour block after the main sight in Leo 2 and the gunner sits below the main sight weakspot, and is safe behind a block of armour.

Keshav, here is my draw how Arjun Mk.I armour placment looks:



and here You have for compare Leo2A4:

Again Leopard-2:




Just compare how looks armour after main sight in Leo-2A4 and Arjun. The protection is far far better in Leo-2A4 in that case.

 

[ersakthivel]

Keshav, here is my draw how Arjun Mk.I armour placment looks:



and here You have for compare Leo2A4:

Again Leopard-2:




Just compare how looks armour after main sight in Leo-2A4 and Arjun. The protection is far far better in Leo-2A4 in that case.

Your idea about ARJUN mk-1's armor placement is wrong because you cannot offer any convincing replies for the queries raised in my post no-4895,

The queries you failed to clarify are,

1.wrong positioning of the Tc's seat to suit your thin armor behind the main sight theory , take a look at the following hobby draw of yours. you have placed the Tc seat 450 mm in front of it's actual position to suit your thin main sight backside armor.

2.inability to explain where the blue optics (Tc's panromic sight)is fixed?

The pic no-3 below clearly establishes that the blue optic (panromic sight is situated well below the roof and on the right side wall of the white block behind the orange box)

The electric light also looks little slanted . WHY?

3. Also the turret sides of the ARJUN is beefed up with composite armor in ARJUN MK-2 version , So I really doubt whether the designers of ARJUN mk-2 would have left such a really thin LOS armor behind the main sight as whatever arrangement of LEO-2 is doable on the ARJUN as well.

Also give us the draw showing the seating position of Tc and the gunner in LEO-2

 

[militarysta]

lol get back and red last 20 pages
the crew on picture is not in scale (its like
children not adults) and on any photo is clearly
visible where armor ends after main sight.
Arjun after main sight have only circa 50% of
Leo2A4armour tcbickness: 650mm in Leo2A4 and circa 330-350mm LOS in Arjun.

 

[ersakthivel]

utter nonsense. and this is why:

shape of mantlet in this external picture of arjun, and picture of the main gun are identical, even the couloration matches...

What you refer by SHAPE of the matlet in the external picture of ARJUN is actually not the mantlet but armor plate above the mantlet plate.

The mantlet sits more than 300 mm behind the armor plate look at the small PIC NO-6 in the set of pictures below.

dark green thick part, then a trapezoidal cylinder connecting to the barrel shroud.
you can see the latches for the barrel shroud, and count them, exact same number, 3 with that ugly tube thing on the end, you'd only be able to see 2 latches,
and the mantlet would be completely flat on front, or there'd be a hole.
this is the ugly truth staring you right in the face. you might not like it, i don't care.
here's another ugly truth. in all the pictures i've seen of the arjun mk.2 in none of them this part has been up-armoured.

So no ugly truths AFAIK

 

[ersakthivel]

lol get back and red last 20 pages
the crew on picture is not in scale (its like
children not adults) and on any photo is clearly

Actually crew on the picture is not the point. the position of the Tc's seat 400 mm in front of it's actual position is the point

you have placed the Tc 400 mm infront of where he should actually be is the point.

look at the seating position of the gunner in the photo. His back is in line with the front edge of the crew hatch.


but in your picture you have placed him 400 mm in front of his true position to suit your lower LOS armor behind main sight theory.That is a clear mistake. It has nothing to do with whether the persons sitting inside the tank are kids or men.

for your visible roof vision block theory an explanation is given in post no-4901,

if you convincingly contradict it and explain the queries regarding the panromic Tc's sight placement ,then I will accept your position on this.

visible where armor ends after main sight.
Arjun after main sight have only circa 50% of
Leo2A4armour tcbickness: 650mm in Leo2A4 and circa 330-350mm LOS in Arjun.

All I wanted was a point by point explanation which was not given by you in the past 20 pages.

I know you will never be able to explain the position of blue optic(Tc's panaromic sight ) besides the clearly visible side wall of the white block behind the orange box above the gunner.

So no LOL this.

 

[Kunal Biswas]

Keep out such ways..

lol, (its like children not adults)

 

[ersakthivel]

This topic was debated before..

------------------------

http://www.ibd-deisenroth-engineering.de/news.html

-----------------------

Such an upgrade can be done with help of many foreign firms with DRDO..

But its not official..

It is already being done in MK-2 , it seems from the prototype photographs, So in MLU it can be done on MK-1s as well.

 

[ersakthivel]

the above is the LEO 2 photo posted by methos,

Just down load and magnify the pic -3 by 300 percent.

Then look at the pic no-3 and the side ways mounted position of blue optic(tc's panromic sight )

Where is the blue optic mounted, Is it hanging in the air?

it is clear from the picture that it is being mounted more than 300 below the roof level of ARJUN inner turret,
There is an oil leak type stain above the blue optic, originating from red rod above the blue optic,

if there is no wall, then Is it hanging in the air?

Also in the pic no-3 a small orange plate below the orange box is( being marked by red arrow ) shown as receiving daylight,

But there is a dark shadow below the raised thin orange plate, Where is the shadow falling?

AFAIK the purpose of the armor block above the gunner's head in LEO-2 is same as that of the block (on which the blue optic is mounted)behind orange FCS box , as it is no rocket science .

Considering the turret of ARJUN is significantly wider than LEO , there is no need for ARJUN's armor block behind the main sight to start at the end of the main gun mantlet cutaway as that of LEO-2. AFAIK It can start a bit to the right of main gun cutaway in ARJUN.

if some one has any doubts still remaining , please look at the two pics of LEO and ARJUN below

The dimensions mentioned above are not mine.

But there is a distance of more than 300 mm between the gun mantlet plate left edge and main sight right edge in ARJUN(refer the space is more than the width of the driver's head in the pic),

Is it there in LEO-2?
Answer is BIG NO. Unable to comprehend this people continue to insist that there is no significant LOS armor behind the main sight in ARJUN, blindly comparing it to LEO-2.

that's why no one can explain the PIC-3 Tc's panaromic sight (blue optics placement ).

 

[ersakthivel]

See the small side step inside the ARJUN turret (right side end of blue lines )is just equal to the width of the driver's head in the picture above,

So there is no need for LEO like block in ARJUN over the gunner's head, because

1. In LEO gunner sits behind the main sight, as there is no gap between the gun mantle plate and main sight

2. In ARJUN the gunner sits behind the space between the mantlet plate and the main sight , so there is no need for heavy protruding armor above his head.

3. That's why the armor block starts little right of the gunner's head in ARJUN

4. To comprehend all this one should have some ideas about engineering drawing to say the least.

just doing pic and choose photo based explanations won't do.


At the right side end of the two red lines some thing heavy is bolted to the inner roof of ARJUN,

What is that?

Any answer from our defence professionals?

 

[militarysta]

@ersakthivel

You really have no idea what you seen on photo

1. This "blue optic(tc's panromic sight )" on picture no.3 is electric light (on the left from orange slopped box) and on right sight it's indicator turret azimuth -it have nothin common whit ANY panormic sight. It's first.
2. Second - all three parts - electric light on the left form slopped orange FCS part and those indicator turret azimuth on the right are mounted to the turret roof. Picture is done whit some angle and all three parts are mounted to the turret roof. It's clearly visible on photos.

those parts are mounted to the turret roof. You are still thinking that turret roof is slopped armour after main sight. No it's not. But it's funny when you confuse this again and again.