Arjun Main Battle Tank (MBT)

[navkapu]

Slope composite sandwich Armour if slanted a projectile hit will cause greater damage same is with the case of kanchan armour.

 

[sayareakd]

any idea how LAHAT was fired from Arjun ???

@Damian i am waiting for my answer................. thanks.

 

[pmaitra]

Slope composite sandwich Armour if slanted a projectile hit will cause greater damage same is with the case of kanchan armour.

I see. Thanks for the information.

 

[Storm shadow]

@pmaitra,
he was right but he did not explained the reason.Let me try.
As you know current mbts use composite armor which are made of Tu steel,glass reenforced plastic,carbor composite,kevlar etc but the most important component is ceramic tiles(like boron carbide,aluminium nitritde,alumina etc).They are very very hard and provide the primary protection against FSAPDS and shaped charge.But at the same time,they are very very fragile.So after taking a hit the tile gets destroyed.For a perpendicular armor one hit will damage minor portion of the armor.But if you slop it,the round will get ricocheted and damage far larger portion of the armor rendering it vulnerable to successive hits.That's why most modern tanks use perpendicular armor instead of slopped armor.Hope this helps.

 

[Damian]

I understand most of what you said except why Arjun is fine without sloping armour. It is sloping in azimuth, not sloping in altitude, while Abrams is sloping in both.

Byt armor in Arjun is sloped!

Now please tell me why is unsloped armour in Arjun better than a hypothetical sloped armour for Arjun? This is in the altitudinal dimension. Kindly explain.

As above, armor in Arjun is sloped, it is not sloped in both dimensions (axis?) but it is sloped.

@Damian i am waiting for my answer................. thanks.

It use special sabot so it can be fired from 120mm gun (LAHAT calliber is 105mm) this sabot also have special rings so LAHAT itself will not spin due to rifling of gun.

As you know current mbts use composite armor which are made of Tu steel,glass reenforced plastic,carbor composite,kevlar etc but the most important component is ceramic tiles(like boron carbide,aluminium nitritde,alumina etc).They are very very hard and provide the primary protection against FSAPDS and shaped charge.But at the same time,they are very very fragile.So after taking a hit the tile gets destroyed.For a perpendicular armor one hit will damage minor portion of the armor.But if you slop it,the round will get ricocheted and damage far larger portion of the armor rendering it vulnerable to successive hits.That's why most modern tanks use perpendicular armor instead of slopped armor.Hope this helps.

This is not true.

1) Modern ammunition is not ricocheting.
2) Ceramic tiles are not main component of modern composite armor.
3) Modern composite armor (at least western modern composite armor) use layers of different steel alloys types like RHA, HHS etc. There aslo different heavy metal alloys like Tugnsten alloy or Depleted Uranium alloy, sometimes backed up by other materials, for example it is reported that lates armor package for M1A1SA and M1A2SEP use DU alloy plates encased in grapite coating and this is encased between two steel plates, but how many such layers are in armor it is unknown.

Besides this modern western composite armors use dynamic elements inside, these dynamic elements are different types of resin, rubber etc. encased between layers of steel.

Of course there are ceramics but I doubt that these are still cheap but not effective alumina and similiar things, rather something more advanced.

 

[Damian]

BTW here are some computer simulations showing how modern ammunition reacts with armor.

M829 - YouTube
829m2 - YouTube
ERA - YouTube
WOERA - YouTube
era2 - YouTube
mango4 - YouTube
mango3 - YouTube
mango2 - YouTube
DZ - YouTube
dz4 - YouTube

 

[p2prada]

Arjun's current design was implemented in the 80s. Give it some more time and you may see a better design in the next 2 years.

 

[pmaitra]

@pmaitra,
he was right but he did not explained the reason.Let me try.
As you know current mbts use composite armor which are made of Tu steel,glass reenforced plastic,carbor composite,kevlar etc but the most important component is ceramic tiles(like boron carbide,aluminium nitritde,alumina etc).They are very very hard and provide the primary protection against FSAPDS and shaped charge.But at the same time,they are very very fragile.So after taking a hit the tile gets destroyed.For a perpendicular armor one hit will damage minor portion of the armor.But if you slop it,the round will get ricocheted and damage far larger portion of the armor rendering it vulnerable to successive hits.That's why most modern tanks use perpendicular armor instead of slopped armor.Hope this helps.

Thank you for the great explanation. Makes sense.

Byt armor in Arjun is sloped!

Damian, do you understand the terms azimuthal and longitudinal? Apparently you don't. So please go back and read my post and try to understand what you quoted. Then try to understand the math I did and correct me if there is any error.

We are having a communication problem here.

If you say Arjun's armour is sloped, you are simply making no sense. Specify the dimension, and then you make sense.

 

[Damian]

Damian, do you understand the terms azimuthal and longitudinal? Apparently you don't. So please go back and read my post and try to understand what you quoted. Then try to understand the math I did and correct me if there is any error.

It seems that You don't understand. Armor to be sloped don't need to be sloped like on T-34 where armor is sloped from vertical axis, on Arjun front turret armor is sloped in azimuth from turret center axis, like on Leopard 2 early variants.

Because modern ammunition is not ricocheting, then such angling is as good as angling from vertical axis or like on M1 Abrams or Challenger 2 angling front turret armor in both axes.

Now, Your matchs seems to be ok, and there is explanation even why on M1 or CR2 armor on turret front is as it is, because Yanks and Brits where kneweing that front turret armor will not be hit only from 0 degrees from turret center axis, but also up to 30 or more degrees from turret center axis, so it needs to provide excellent protection at any predictible hit angle.

There is really not many problems with Arjun front armor geometry, besides stupidly placed main sight (maiking it vurnabale and making front armor in this place weak), and weakly protected side armor at predictible hits within safe manouvering angles +/- 10-30 degrees from turret center line.

BYW I have a request, there are some good photos of Arjun main sight assembly hole? Need to check something.

We are having a communication problem here.

Perhaps, my english is not too good.

If you say Arjun's armour is sloped, you are simply making no sense. Specify the dimension, and then you make sense.

First part of my post, but possibly due to my english limitations it can be not understandabale for You.

Arjun's current design was implemented in the 80s.

It is possible that Kanchan armor of Arjun is based on early Leopard 2 perforated armor design.

 

[pmaitra]

^^

Storm shadow and navkapu have explained clearly and I understood.

Thank you for your efforts.

 

[Storm shadow]

@Damian,
How do you know that Kanchan is based on early Leo 2 armor??All I can see in your posts are just some baseles prediction and nothing else.

 

[pmaitra]

Damian,

From what I understand, perforated armour is placed outside the tank with some spacing provided between it and the body of the tank. ERA is placed on the the body of the tank. Kanchan type sandwich armour is tiles placed between two or more metal surfaces.

http://www.idexuae.ae/ExhibitorLibrary/1441/MTL_Perforated_Armour_-_IMPAS_2.pdf

Question: Will a projectile whose locus is parallel to the surface plane have the same effect on an Abrams as on an Arjun if it hits at a very low angle with the main axis?

Question: Did you imply that Abrams is sloped in both azimuthal and longitudinal PoV because they were expecting people to hit the tanks from positions like from top of buildings etc.?


Storm shadow,

Carrying on from your last post, Kanchan armour probably uses tiles of ceramic or other material (we don't know for sure), but it is placed between two layers nonetheless. So, even if the armour is sloped, it will not strip off the tiles. The tiles might be cracked but it will in some likelihood stay where it is, between the two layers, the inside layer being intact and the outside layer being damaged.

Navkapu,

I am trying to plug holes in my understanding. You said that Kanchan armour is not useful when sloped. Why so? Even if it is sloped, the outer layer is still metal and offers more effective thickness than if it is perpendicular to the locus of the projectile. Please explain.

 

[Storm shadow]

@pmaitra,
I will try to answer the question asked to me.
The ceramic tiles when hit,are not just get broken but turned to dust.So they will not remain intact even if encased(as in all composite armor).That's the biggest problem associated with and that's why moder armor developers(including the DRDO)use micro fibre filaments to reinforce the ceramic tiles to try to keep them intact to a certain extent.

 

[Damian]

How do you know that Kanchan is based on early Leo 2 armor??All I can see in your posts are just some baseles prediction and nothing else.

Well, Arjun is more or less based on Leopard 2 design, and Germans were helping in designing Arjun so why not?

From what I understand, perforated armour is placed outside the tank with some spacing provided between it and the body of the tank. ERA is placed on the the body of the tank. Kanchan type sandwich armour is tiles placed between two or more metal surfaces.

Perforated armor can be placed outside and inside of armor cavity. From sources we know that composite armor in Leopard 2 is builded mainly from perforated RHA plates with materials encased between them.

If Kanchan is more ceramic orientated then it can be based on the same principles as UK/US Burlington armor.

Question: Will a projectile whose locus is parallel to the surface plane have the same effect on an Abrams as on an Arjun if it hits at a very low angle with the main axis?

Because both tanks use completely different composite armor, then projectile will react with armor differently.

Question: Did you imply that Abrams is sloped in both azimuthal and longitudinal PoV because they were expecting people to hit the tanks from positions like from top of buildings etc.?

No. It is designed such way because front turret armor can be hit at 0 degrees from turret center axis up to 30+ degrees from turret center axis.

This is why front turret armor is angled in both axes ti increae it's thickness at most predictible hit angles.

I don't know how simpler explain this.

The ceramic tiles when hit,are not just get broken but turned to dust.

This is why in western composite armors, ceramics were mostly replaced by NERA and NxRA elements backed up by heavy metal alloys and different types of steel and other metals plates.

I read few years ago that in reality besides weight savings ceramic armor don't offers significant protection levels increase over different types of metals, or something like this.

 

[Storm shadow]

@Damian,
Yeah,the ceramic tiles are problematic indeed due to the fragility.But that does not mean that they do not offer greater protection.The Boron Carbide is the hardest material on earth and at a equivalent weight they are between 6-8 times harder than RHA.That's why the modern composite armor is lighter but bulky.NERA is definately a great thing as it is virtually immune to multiple HEAT and FSAPDS strikes.Even the HEMRL also developed and validated a NERA in 2010 for Arjun tanks.They used multiple layers of rubber and other inert materials encased in carbon composite and glass reinforced plastic and ceramic inserts.The IA conducted the user trials and cleared for production.But I don't know whether they will be added to Arjun MkII or not.The Prasun chor Gupta claimed that the MkII turret will use these armor modules on the sides in place of those storage boxes to improve the side protection and also to the front turret and glacis.But I am still not sure about that.
By the way,I thought the Leopard 2A6 are still using ceramic tiles.Even the south koreans are using them in K 2.But can you prove otherwise.Would definately like to know. . . .

 

[Kunal Biswas]

Damian,

From what I understand, perforated Armour is placed outside the tank with some spacing provided between it and the body of the tank. ERA is placed on the the body of the tank. Kanchan type sandwich Armour is tiles placed between two or more metal surfaces.

http://www.idexuae.ae/ExhibitorLibrary/1441/MTL_Perforated_Armour_-_IMPAS_2.pdf

Question: Will a projectile whose locus is parallel to the surface plane have the same effect on an Abrams as on an Arjun if it hits at a very low angle with the main axis?

Question: Did you imply that Abrams is sloped in both azimuthal and longitudinal PoV because they were expecting people to hit the tanks from positions like from top of buildings etc.?


Storm shadow,

Carrying on from your last post, Kanchan armour probably uses tiles of ceramic or other material (we don't know for sure), but it is placed between two layers nonetheless. So, even if the armour is sloped, it will not strip off the tiles. The tiles might be cracked but it will in some likelihood stay where it is, between the two layers, the inside layer being intact and the outside layer being damaged.

Kanchan Armour plates consist of many different metals these plates are main constitute of Kanchan Armour, Here a diagram states the idea:

Also Arjun MK-1 turret have straight Armour so does any other, the only thing is they kept getting addon over turrets, Its Not difficult to get Arjun such kind of Update..


LEO2 :

Almost the same turret with Additional sloped Armour welded on front so does on sides..

T-90:

Minor deign change on Turret but basically same architecture..

On Arjun MK-1, Some redesigning is important or Addon Armour used over LEO A4 Evolution is needed to rectify the exposed areas..
But Like Germans did regarding Sights on LEO2-A5/6/7, Arjun MK-1 should follow the same..

 

[Kunal Biswas]

Well, Arjun is more or less based on Leopard 2 design, and Germans were helping in designing Arjun so why not?

This will give you some Idea abt Kanchan development in 80s..

The Kanchan Armor - Frontier India - News, Analysis, Opinion

 

[Storm shadow]

@Damian,
It's true that India did aquire the design of Leopard 2A4 but that's all.Actually,we wanted the Chobham armor(or whatever it is called) developed by the Brits.But they denied.So the DMRL started development of the new composite armor and kept upgrading it with time.As far as I know,the latest module that went into production tanks came as late as 2004 or so.And it does not use RHA to a very great extent.

 

[Damian]

The Boron Carbide is the hardest material on earth and at a equivalent weight they are between 6-8 times harder than RHA.

The question is cost, of course ceramics like Boron Carbide are used, yes but the question is how great % of modern composite armor is made from such ceramics. In my opinion based what I seen, these ceramics tiles are rather thin, encased between metal plates, and these metal plates are seprated by dynamic elements.

By the way,I thought the Leopard 2A6 are still using ceramic tiles.Even the south koreans are using them in K 2.But can you prove otherwise.Would definately like to know. . . .

From Germans I know that actually they seen ceramics as too expensive when they were designing Leopard 2, this is why they did not want British Burlington armor and made their own, much simpler armor based on perforate steel armor, they added with time some ceramic materials and dynamic elements, at least this is what I know.

K2 is using probably modern composite armor with dynamic elements, different metal plates and ceramics.

Also Arjun MK-1 turret have straight Armour so does any other, the only thing is they kept getting addon over turrets, Its Not difficult to get Arjun such kind of Update..

But Arjun Mk1 ad Leopard 2 before KWS upgrades, have front turret armor angled from turret center axis not from vertical axis.

Leopard 2 tanks after KWS II upgrade use wedge shaped NERA/NxRA armor placed on turret front.

http://img217.imageshack.us/img217/9099/51f136ad21f1.jpg

Kunal, this tank is not T-90A but it is one of Object-187 prototypes. T-90A and T-90MS just use similiar if not the same turret design. This turret also have sloped front armor, but not sloped from vertical axist but from turret center axis.

Kanchan Armour plates consist of many different metals these plates are main constitute of Kanchan Armour, Here a diagram states the idea:

It's true that India did aquire the design of Leopard 2A4 but that's all.Actually,we wanted the Chobam armor(or whatever it is called) developed by the Brits.But they denied.So the DMRL started development of the new composite armor and kept upgrading it with time.As far as I know,the latest module that went into production tanks came as late as 2004 or so.And it does not use RHA to a very great extent.

So it seems that Kanchan design is based on Burlington armor principles, this means that Kanchan is mostly optimized against HEAT warheads not APFSDS ammunition, this means that Arjun Mk1 protection against APFSDS should be similiar to early Leopard 2A4 and basic M1A1 if it use similiar armor thickness, this means that Arjun Mk1 protection vs APFSDS should be up to ~600mm RHAe.

By the way, You don't know how much RHA is used in Kanchan armor, because RHA can be used as outer and back plates, but also as internal plates in composite blend itself.

 

[Storm shadow]

@Damian,
How can Arjun MkI's front armor protection be 600 mm RHA when it defeated both the IMI mk2 and BM 42M Lecalo rounds fired from point blank range????Because according to the tank protection level site(which you guys often reffer),both have aromor penitration of about 650mm RHA at 2000 meter.
Besides,according to that site the DM 63 has armor penetration of 750 mm RHA at 2000 meter when fired from a L 55 smoothbore and the Indian 120mm FSAPDS has about 680mm RHA at 2000 meter which did not seem 'way inferior' to me.So,can we say that the tank protection level website is unreliable at best or am I missing something????
PLEASE don't get me wrong,all I want is knowledge.Hope you can help.