Armoured Vehicles Discussion Thread

[Surya]

After a 1300km trek the only tank whose engine didnt fail was the T-90. All other tanks died an awful death and had to be replaced with spare tanks to finish the trials. Uralvagonzavod was the only manufacture that didnt even bring a spare tank to the trials. The T-90 didnt even develop a single oil leak

Compare it to our testing results (there is a PDF which mentions breakdowns)

[Virupaksha]

Can the MP\MLA covering where the factory is located be contacted to raise this in Parliament?

Why for?? Has anybody talked of dismissing those factory employees??

They will be paid their wages to enjoy and sit on their a$$es.

[Vivek K]

All this noise from IA regarding - we ordered 1000s of T-90 bcoz Arjun cannot meet production targets and now this!! Typical IA!!

[Surya]

Why for?? Has anybody talked of dismissing those factory employees??

They will be paid their wages to enjoy and sit on their a$$es.

what about the ancillary units and infrastructure?

[SaiK]

It doesnt make any sense at all. No commercial establishment will be willing to close its production lines for even an hour and we're talking a year plus! Wonder if the CAG can lambast the government over this one.

lambasting works for aam junta satisfaction. operation brass tacks needs arjun production line fully occupied.

I say, keep producing common parts between mk1 and mk2. And, perhaps ask for another T90 vs Arjun battle or perhaps get the M1Abrhams/merkava or other tanks to pit on an exercise mode.

Keep our IA engaged to ensure, they have to forget this infatuation towards russkie beauties.

[srai]

Arjun Tank Production lines may be idle for approx 30 months

The production line of the India’s own Main Battle Tank “Arjun” will see a idle time for around 30 months. As we reported in August, that around 85 tanks have been already delivered to Indian Army. Currently the production is at its fag end for the initial 124 tank order. The issue lies in delayed ordering. The Defence Acquisition Committee (DAC) had finalised the order for the next batch of 124 tanks around June 2010. As per DRDO, the lead time for production of the next batch is 30 months.

DRDO says that the delay is in production is unavoidable due to delayed ordering.

The production order for next lot of Arjun Tank is not specific to Mk2. DRDO says that it made the decision to deliver Mark 2 tanks to the Indian Army. As per DRDO, the Phase one trials of Mark 2 Arjun Tanks are scheduled for June 2011 and the Phase two trials are scheduled for June 2012.

The production of the next lot of 124 tanks may be contigent on the results of the Phase one, two trials. As per DRDO, if the trials go well, the production can restart in mid 2013 and all the deliveries can be made 30 months.

This is quite tragic that it becomes laughable ...

When the lead time is 30 months for next batch is matched with the 50 tanks/year production capacity and IA's small token orders of 124 tanks per batch, DRDO would need to have the second batch of 124 tanks ordered just before the first batch of 124 tanks starts production. This is because 30 months (or 2.5 years) is the time it takes to complete the production of a 124 Arjun tank batch order at 50 tanks/year. So going by this there will be another 30 months gap after 124 Mk.2 are manufactured as the IA doesn't seem to order in sufficient quantities for the current production infrastructure to work.

Given this oddity, how can the Arjun ever be produced in large quantities? IMO, only 248 Arjuns (124 Mk.1 + 124 Mk.2) are likely to be produced before "switch" (i.e. "wait") to FMBT occurs as it would be close to 2020 by then.

Adieu Arjun!

[SaiK]

well.. I am calling it Operation Sabotage II, for lack of better words.

[dinesha]

Development of Improved Indian Arjun Complete: DRDO
http://www.defensenews.com/story.php?i= ... =ASI&s=LAN

India's state-owned Defence Research and Development Organization (DRDO) claims that it has completed upgrades on the Arjun tank, replacing existing German engines and transmission systems with homemade systems.

[d_berwal]

Because every few weeks somebody comes up asking why sloped armor is not used in the Arjun and how that makes it inferior etc, i have made two easy to understand explanatory images to show that sloped armor is not all that is made out to be (esp. by discovery channel etc.). Here's a short sloped armor 101 (or rather basic geometry 101)

For the same weight the 'Line of Sight' thickness(and hence the level of protection) will be the same for a slab of both sloped and non sloped armor.
There are only a handful of modern tanks that use significantly sloped armor.

A sloped armour plate provides better protection than a vertical armour plate of the same thickness.
- This is due to two reasons.
1)The first is because the sloped armour is wider from a horizontal view than the vertical armour, and
2)thus the shells fired at it will have to travel a greater distance through the armour.

While the sloped armour seems superior in terms of relative thickness alone, this does not justify the use of sloped armour to same steel, as the same amount of steel is needed to achieve the same protection. This is because the sloped armour plate will have to be longer to cover the same height

The actual bonus comes from the shells deflecting. The more sloped an armour plate is, the more likely it is that the incoming shell will deflect.

Very simple physical model of the slope effect. Kinetic energy absorbed by armour is proportional to the square of the sine of angle (maximal for 90°). Friction and deformation of target are neglected
http://en.wikipedia.org/wiki/File:Slope ... -slide.png
How a groove caused by projectile impact increases the effective incident angle
http://en.wikipedia.org/wiki/File:Armor ... groove.png
Illustration of some possible effects that can occur when a projectile impacts sloped armour
http://en.wikipedia.org/wiki/File:Proje ... ffects.jpg

The second aspect of slope is the asymmetrical force acting on the penetrator. When a projectile strikes a sloped plate, the side of the penetrator closest to the plate will suffer more force, erosion, and damage than the opposing side. This puts an unbalanced force on the rod, turning it in towards the plate – and then into the opposite direction. The penetrator takes a longer overall route through the armor, resulting in less penetration of sloped armor. (See: Rheinmetall Handbook on Weaponry [figure 1128] (1982))

Exactly how likely the projectile is going to deflect depends on:
Firstly, all projectiles will ricochet. The real question is at what angle and velocity do they ricochet.

- A complex model has been developed to predict the angle at which a projectile is expected to ricochet, this is called the ‘critical ricochet angle’ (See: J. Phys. D. Appl. Phys. Vol 12-1979 pp. 1825—1829.)

The critical ricochet angle is measured from the vertical plane [i.e. 90° is horizontal].
- A rod of 10:1 L/d [Length to rod Diameter ratio] @ 1.7km/s should ricochet at ~78° when made of steel,
Tates Ricochet formula.

J Phys D Appl. Phys. Vol 12-1979pp 1825-1829. "A.Tate's" ricochet law and the formula is as follows .


p xV² (L² + 1) / p

------ x ------- x 1 + / ------ x 0.6666 = tan³ + [modifier] =the ‘critical ricochet angle’

Y L / t


Where ....
p = projectile density (g/cm³)
t = target density (g/ccm³
V= striking velocity (km/s)
L= L/d ratio (rod length to diameter)
Y= projectile yield strength

Modifiers to the ‘tan value’....
- 0.9 for each T/d above 1:1
+ 0.3 if the projectile has a sharp nose (> 60° cone)
-0.3 if the projectile has a blunt nose (< 30 ° cone)
-0.1 if the projectile is spinning.

Projectile Yield strengh is usually
Steel rod ~1.9 to ~1.7 ‘GPa’ or BHN = 600 - 500
WHA/DU rod ~1.6 to ~1.4‘GPa’ or BHN= 450 -400

HVAP ~ 1100m/s ….

8.4 x 1.1² 4.0² +1 / 8.4

--------- x ------- x 1 + / ------------- x 0.667 = tan³ + modifier + 0.3 – 0.1 – 0.9 [ - 1.8]

2.0 4.0 / 7.8 [ 4.8]


5.06 x 4.25 x 2.03 [ 2.32] x 0.67 + 0.2/ - 0.7/ - 1.6=
43.6 x 0.67 = 29.2 cube root = 3.15 + 0.2= 3.35 = Tan of 18° or 72° Vs T/d 1:1
43.6 x 0.67= 29.2 cube root = 3.15 –0.7 = 2.45 = Tan of 22° or 68° Vs T/d 2:1
49.9 x 0.67= 33.4 cube root = 3.30 – 1.6 = 1.7 = Tan of 30° or 60° Vs T/d 3:1 comp

Steel 44mm 10:1 L/d APFSDS ~ 1700m/s ….

7.8 x 1.7² 10.0² +1 / 7.8

--------- x ------- x 1 + / ------------- x 0.667 = tan³ + modifier 0 /- 1.2/- 3.3

2.0 10.0 / 7.8 [ 4.8]

11.27 x 10.1 x 2 x 0.67 = Tan³ = 5.52 = 10° or 80°= 85±7°
11.27 x 10.1 x 2 x 0.67 = Tan³ = 5.52 - 1.2 = 4.32 = 13°or 77° = 82°±7°
11.27 x 10.1 x 2.27 x 0.67= Tan³ = 5.77 - 3.3= 2.47 = 22°= 68° = 73°±7°


Steel 41mm 18:1 L/d APFSDS ~ 1700m/s ….

7.8 x 1.7² 18.0² +1 / 7.8

--------- x ------- x 1 + / ------------- x 0.667 = tan³ + modifier 0 /- 1.8/- 3.6

2.0 18.0 / 7.8 [ 4.8]

11.27 x 18.05 x 2 x 0.67 = Tan³ = 6.73 = 9° or 81°= 86±7°
11.27 x 18.05 x 2 x 0.67 = Tan³ - 1.8 = 4.9 = 12°or 78° = 83°±7°
11.27 x 18.05 x 2.27 x 0.67= Tan³ - 3.6=3.42 = 16°= 74° = 79°±7°

Steel 41mm 9:1 L/d APFSDS ~ 1500m/s ….

7.8 x 1.5² 9.0² +1 / 7.8

--------- x ------- x 1 + / ------------- x 0.667 = tan³ + modifier 0 /- 1.8/- 3.6

2.0 9.0 / 7.8 [ 4.8]

8.77 x 9.11 x 2 x 0.67 = Tan³ = 4.9 = 12° or 78°= 83±7°
8.77 x 9.11 x 2 x 0.67 = Tan³ = 4.9 - 1.8 = 3.1= 18°or 72° = 77°±7°
8.77 x 9.11 x 2.27 x 0.67= Tan³ =5.1-3.6= 1.51 = 33°= 57° = 62°±7°


DU 32mm 10:1 L/d APFSDS ~ 1600m/s ….

17x 1.6² 10.0² +1 / 17

--------- x ------- x 1 + / ------------- x 0.667 = tan³ + modifier - 0.4 /- 1.8 /- 4.9

1.3 10.0 / 7.8 [ 4.8]

33.5 x 10.1 x 2.48 x 0.67 = Tan³ 8.6 –0.4 = 8.2 = 7° or 83°= 88±7°
33.5 x 10.1 x 2.48 x 0.67 = Tan³ 8.6 – 1.8 = 6.8 = 9°or 81° = 86°±7°
33.5 x 10.1 x 2.88 x 0.67= Tan³ 9.05 –4.9 = 5.6 = 10°= 80° = 85°±7

DU 25mm 20:1 L/d APFSDS ~ 1400m/s ….

17x 1.4² 20.0² +1 / 17

--------- x ------- x 1 + / ------------- x 0.667 = tan³ + modifier - 0.9 /- 2.7 /- 7.0

1.3 20.0 / 7.8 [ 4.8]


25.6 x 20.05 x 2.48 x 0.67 = Tan³ 10.0 –0.9 = 9.1 = 6° or 84°= 89±7°
25.6 x 20.05 x 2.48 x 0.67 = Tan³ 10.0 – 2.7 = 7.3 = 8°or 82° = 87°±7°
25.6 x 20.05 x 2.88 x 0.67= Tan³ 10.44 –7.0 = 3.44 = 16°= 74° = 79°±7°

DU 25mm 20:1 L/d APFSDS ~ 1600m/s ….

17x 1.6² 20.0² +1 / 17

--------- x ------- x 1 + / ------------- x 0.667 = tan³ + modifier - 0.9 /- 2.7 /- 7.0

1.3 20.0 / 7.8 [ 4.8]

33.5 x 20.05 x 2.48 x 0.67 = Tan³ 10.9 –0.9 = 10.0 = 5° or 85°= 90±7°
33.5 x 20.05 x 2.48 x 0.67 = Tan³ 10.9– 2.7 = 8.2 = 7°or 83° = 88°±7°
33.5 x 20.05 x 2.88 x 0.67= Tan³ 11.44 –7.0 = 4.44 = 13°= 77° = 82°±7°

DU 25mm 30:1 L/d APFSDS ~ 1400m/s ….

17x 1.4² 30.0² +1 / 17

--------- x ------- x 1 + / ------------- x 0.667 = tan³ + modifier - 0.9 /- 2.7 /- 7.0

1.3 30.0 / 7.8 [ 4.8]

25.6 x 30.03 x 2.48 x 0.67 = Tan³ 11.4 –0.9 = 10.5 = 5-6° or 85°= 90±7°
25.6 x 30.03 x 2.48 x 0.67 = Tan³ 11.4 – 2.7 = 8.68 = 6-7°or 84° = 89°±7°
25.6 x 30.03 x 2.88 x 0.67= Tan³ 12.01 –7.0 = 4.95 = 11°= 79° = 84°±7°

DU 25mm 30:1 L/d APFSDS ~ 1600m/s ….

17x 1.6² 30.0² +1 / 17

--------- x ------- x 1 + / ------------- x 0.667 = tan³ + modifier - 0.9 /- 2.7 /- 7.0

1.3 30.0 / 7.8 [ 4.8]

33.5 x 30.03 x 2.48 x 0.67 = Tan³ 12.47 –0.9 = 11.57 = 5° or 85°= 90±7°
33.5 x 30.03 x 2.48 x 0.67 = Tan³ 12.47 – 2.7 = 9.77 = 6°or 84° = 89°±7°
33.5 x 30.03 x 2.88 x 0.67 = Tan³ 13.1 –7.0 = 6.1 = 9°= 81° = 86°±7°

[note 4 ] The effect of ricochet on AP shot
For a 820m/s 3.5:1 L/d Steel APCBC sharp capped shot-the figures should be .......
[PRE]
At muzzle Vs 1:1 T/d thats 64 -74° .
At 2000m Vs 1:1 T/d thats 62 -75° .

At muzzle Vs 2:1 T/d thats 51 -61° .
At 2000m Vs 2:1 T/d thats 40 -50° .

APFSDS Vs
Vs 1:1 T/d at 1000m = 82.6 ±5°
Vs 5:1 T/d at 1000m = 76.5 ±5°

[akimalik]

Hi I have a general question:
When (after many many years) the AF has decided to move away from over-dependence of 1 source. How come the IA seems to be so out-of-sync with this thought process?
Or are they waiting to launch the IA's version of the MMRCA (the MMRCT perhaps)?

[Austin]

After a 1300km trek the only tank whose engine didnt fail was the T-90. All other tanks died an awful death and had to be replaced with spare tanks to finish the trials. Uralvagonzavod was the only manufacture that didnt even bring a spare tank to the trials. The T-90 didnt even develop a single oil leak.

Speaks good about the Tank , the fact that there was no oil leak after some thousand hours of competitive trials might be called sheer luck by observers , but the fact they just took one tank for trials shows their confidence in the tank.

The desert trials in India might have validated T-90's hot performance to give them the confidence.

In firing trials out to 8km's (3km further than the T-90 max effective range) the T-90 achieved a hit rate of 60%. The Arabs were amazed.

Not bad ,hopefully with the new gun in T-90M it would do better , wonder if we would move the production to advanced model of T-90 that can fire long rod ,has better protection and what we need most is the APU.

[d_berwal]

There are only a handful of modern tanks that use significantly sloped armor.

The handful of tanks using sloped armour are:
- Merkava IV
- Challenger 2
- M1A2
- Leclerc
- T-90
- Type 99

[d_berwal]

Speaks good about the Tank , the fact that there was no oil leak after some thousand hours of competitive trials might be called sheer luck by observers , but the fact they just took one tank for trials shows their confidence in the tank.

The desert trials in India might have validated T-90's hot performance to give them the confidence.

what i heard way back in 06 in one of the battle games, a complete T-90 brigade ended up doing 1000+ km in 15-20 days in desert without failures..

- The only crib was it ended the engine life of 15-20% of vehicles as they had been already extensively driven for past couple of years.

[Austin]

d_berwal , If they do well in the desert that would surprises me , I would expect a russian tank to do well in Cold Desert since their environment is predominantly just that but doing a good job against the western biggies for a tank that would cost less then half of these western types is unexpected and commendable.

Did you check IDEX 11 , the Ukrainian folks have displayed Oplot-BM tank
http://www.whq-forum.de/invisionboard/i ... opic=29475

Good photos of IDEX 11 at mp.net link

[chackojoseph]

I am happy with the situation.

1) Mk2 will equalise with any t-90 upgrade coming by 2015 (estimated)
2) 30 Months better utilized.
3) CAG will give danda and babus will be more pro-active in ordering.

[Surya]

I love it - A natasha site claims their tank ran million miles in the desert.

immediately our resident Tin can lovers who previously have come up with every conceivable red herring jump on it

except cough cough

our own tests did not have such results with 2 out of 3 tanks conking off

Mysteriously the report which gave the details has now been pulled off

http://forums.bharat-rakshak.com/viewto ... ne#p836282

College of Defence Management
http://cdm.ap.nic.in/casestudies/casevo ... 20Path.pdf


Rohit, rahul etc - did you save the pdf file?

[manjgu]

very interesting and educative discussion....

so T 90 is not so much a tin can as it is made out to be ? seems to have some stellar qualities!

and

Maintenance is indeed a big issue with tanks uptime...

[Sanku]

so T 90 is not so much a tin can as it is made out to be ? seems to have some stellar qualities!
.

T 90 is a excellent tank with great qualities, the report which lambasts that T 90 broke, misses the entire point that the test was to run a T 90 continuously till it broke to measure what was the longest continuous time it would run without breaking. (Of course T 90 broke that was what the test designed for )

And it was a very decent figure (cant remember it right now)

T 90 had been extensively tested with its own AUCRT in 1999-2000 time frame before the purchase was made (while PNC was ongoing) -- these facts are indeed known since then.

To give context to the same; Arjun went through the same process in 2008-9 time frame.

So no T 90 is not remotely a bad tank, its a great tank, very useful if you want to push into enemy territory at a rapid clip bypassing towns and strongholds.

OTOH if you want to fight pitched battles with possibly a single tank taking on the entire DCB fortifications in Pak-jab, and/or semi-urban pounding Arjun would be much better.

[Aditya_V]

Could it be- T-90 is a great Tank, Arjun is a better Tank

[merlin]

very interesting and educative discussion....

so T 90 is not so much a tin can as it is made out to be ? seems to have some stellar qualities!

Only in the eyes of tin can lovers.

[Vivek K]

Aditya the difference is that Arjun is our own!!

[Sanku]

Could it be- T-90 is a great Tank, Arjun is a better Tank

Of course, that is actually quite the simple truth. There is nothing much to read in here.

But then, how will the thread move.

[Gurinder P]

OTOH if you want to fight pitched battles with possibly a single tank taking on the entire DCB fortifications in Pak-jab, and/or semi-urban pounding Arjun would be much better.

In such a case, I would prefer If DRDO developed a vehicle that had Arjuns hull and armor and the turret with some rapid firing cannon and some AT missiles. Kind of in the likeness of the BMPT.

[RoyG]

Arjun raped tin can during trials.

Tin can lovers : Induct more tin cans.

Arjun lovers :

What's the use? Everybody on BRF including the tin can fanboys know that Arjun is the BEST tank we got. It can also push into enemy territory bypassing towns and strongholds better than tin can. They know that too. T fanboys will come around...just give them some time. A lot like getting over your first car...

[Singha]

I wonder what the IA's ICV plans are (apart from 'stopgaps' like importing 150 light tanks and 300 wheeled recce vehicles). they have never shown any interest in Abhay tech demo and seemed content with producing more BMP2 when everyone and their uncle has been moving quickly to next gen ICVs around the world...and some had better protected and sensored ICVs like bradleys even earlier generation.

there exist a range of bideshi options now that all big players like BAE and KMW have hooked into desi production partners, so production and spares is not a issue anymore...but if we really wanted to develop inhouse design skills there is no alternative to a Abhay-MKI using building blocks from some foreign sources...(sigh)

so when is the BMP3 going to be inducted ?

people say the pakis have built up fortifications and most of pak is thickly populated now. yet I have not seen even talks of developing innovative solutions from current holdings to meet these specific problems like say a twin barrel 30mm cannon on T72 with 6000rds of ammo in a new bustle with metallic beltfeed drums.
or assault bulldozers of the IDF type. Look at IDF, they have even found good use for pattons and shermans lying around in boneyards and glued/bolted some useful kit together than slaving for some uber tfta solution. out of such efforts came stuff like Nemer later.

perhaps I am barking up the wrong tree here, IA's armour corps do not show any IDF style track record of jugaad to my layman's eye...

[pralay]

hmm,
so we are going to play a race with enemy tanks, the one whose tank runs longer distance wins the war.

This will really save lives of soldiers on both sides and no-one will need to fire and fight to win wars just race.
Lets start building a race track for tanks

can lovers why don't you tell this idea to paki government they may accept your proposal(challenge)

I am sure we will now start to see statements like like ... "my tank runs for thousands of miles... so its best tank in world "

[Sanku]

OTOH if you want to fight pitched battles with possibly a single tank taking on the entire DCB fortifications in Pak-jab, and/or semi-urban pounding Arjun would be much better.

In such a case, I would prefer If DRDO developed a vehicle that had Arjuns hull and armor and the turret with some rapid firing cannon and some AT missiles. Kind of in the likeness of the BMPT.

I think some of these features would be in Mk II. However given the higher weight of Arjun (in a diff category) + Mean time before change of engines would ensure that a lighter tank would run faster (including turn around time) and further than a heavier one.

This unfortunately is the basic mechanism of tanks and a trade off which has been true and existed since WW II, and have played out with Tigers and Panthers (and Sherman's) in Normandy and France.

There is nothing T 90/Arjun here and the difference is basically the difference between tanks which weigh differently.

[Sanku]

hmm,
so we are going to play a race with enemy tanks, the one whose tank runs longer distance wins the war.

Yes, actually something quite similar will be done.

This will really save lives of soldiers on both sides and no-one will need to fire and fight to win wars just race.
Lets start building a race track for tanks

Something like this was done precisely in 1971, when strongholds were bypassed rather than slugged out. IA built "race tracks" on which this could be done.

can lovers why don't you tell this idea to paki government they may accept your proposal(challenge)

They tried to do that in Asal Uttar, we broke a dam and flooded their race track.

I am sure we will now start to see statements like like ... "my tank runs for thousands of miles... so its best tank in world "

If you knew even a little bit about the real world and tank warfare, you would know that this is life and death for tanks in many situations.

Reminder -- the Blitzkreig was not done by Tigers and Panthers but done by fairly light tanks. Pretty much their only major Win

[Sanku]

perhaps I am barking up the wrong tree here, IA's armour corps do not show any IDF style track record of jugaad to my layman's eye...

Arent you forgetting the transport and use of tanks in high hills, along with use of light floating tanks in 71 (to harass rivierine traffic) tanks fighting boats, now how much Jugaad you want to see more bhai.

people say the pakis have built up fortifications and most of pak is thickly populated now. yet I have not seen even talks of developing innovative solutions from current holdings

I think IAs plan, is by and large, to bypass the fortifications and hit where there are no fortifications to stop deep thursts. It appears that IA has learnt from IDF that there are NO GOOD ways for Tanks to take on urban strongholds.

[abhik]

T-90 ran 1300km without even an oil leak, Supanalla!
So now I guess we have found the weapon that is going to take us all the way to Kashgar!

[Sanku]

And all those who "ostensibly" root for Arjun, please remember, if all you can do to get there is bad mouth T 90 (for imagined issues) -- you are actually showing that Arjun has nothing going for it (which is not true)

Arjun is a fantastic tank because T 90 is a great tank

[Sanku]

T-90 ran 1300km without even an oil leak, Supanalla!
So now I guess we have found the weapon that is going to take us all the way to Kashgar!

Perhaps not Kashgar, but it will be T 90 which will take us to RYK.

[abhik]

A sloped armour plate provides better protection than a vertical armour plate of the same thickness.
- This is due to two reasons.
1)The first is because the sloped armour is wider from a horizontal view than the vertical armour, and
2)thus the shells fired at it will have to travel a greater distance through the armour.

While the sloped armour seems superior in terms of relative thickness alone, this does not justify the use of sloped armour to same steel, as the same amount of steel is needed to achieve the same protection. This is because the sloped armour plate will have to be longer to cover the same height

So you agree Points 1 and 2 on their own are simply BS. Then the only ways sloped armor can be advantageous are
1)the penetrator taking a longer route through the armor or
2) the penetrator ricocheting , right?
On point 1) you din't explain at what angle of sloping does this really become significant enough to be considered,
next on point 2) you are suggesting that for an modern KE round to ricochet the angle of sloping has to be 70-90 degrees(!), did I understand your calculations correctly?

[Austin]

Iit will be T 90 which will take us to RYK.

The problem with T-90 is damned if you do, damned if you don't. You have already been judged

[pralay]

I am sure we will now start to see statements like like ... "my tank runs for thousands of miles... so its best tank in world "

If you knew even a little bit about the real world and tank warfare, you would know that this is life and death for tanks in many situations.

Reminder -- the Blitzkreig was not done by Tigers and Panthers but done by fairly light tanks. Pretty much their only major Win

Sanku ji,
does T-90 fit in light tank category?
light is about low weight and better speed.

Iit will be T 90 which will take us to RYK.

Don't it need to survive enemy attack to reach RYK? or again its just race

[Arya Sumantra]

Sloped Armour:
Formula:
T(L) = T(N) / cos(θ)
* T(L): Line of sight thickness
* T(N): Normal thickness
* θ: Angle of the sloped armour plate from the vertical
For example, armour sloped sixty degrees back from the vertical presents to a projectile travelling horizontally a line-of-sight thickness twice the armour's normal thickness, as the cosine of 60° is ½.

This theory is valid only for ISOTROPIC materials (same strength in ALL directions)- a theoretical ideal to which only older generation materials-metals approximate. Obviously what is the use of higher thickness if the strength is lower at that angle? And even the directionally cold rolled and heat-treated steels may not exhibit all that theoretical isotropy in strength.

It is evident that this theory was devised only to get the most out of older generation relatively isotropic materials. The future tanks are however going to depend on higher strength to weight ratio materials in order to improve their Thrust to weight ratio and multiple layers for better protection. And these high strength low weight materials are naturally the composites which are ANISOTROPIC.

Anyone who is trying to combine sloped armour theory with ANISOTROPIC materials of the future is basically trying to fit a Square peg in a Round hole. I sincerely hope IA has no ridiculous plans to use a theory (sloped armour)designed to maximize gains from older materials for its futuristic tanks using futuristic high strength to weight materials and make us a laughing stock in the world.

And regarding agility, every tom dick and harry know that if you have to pull breaks to fire everytime your speed is destroyed and fuel efficiency lost. Guess who would be more agile and accurate.

[Sanku]

Sanku ji,
does T-90 fit in light tank category?
light is about speed, and T-90 is no match for Arjun.

No Sir, light is about weight only (unless you are talking quantum mechanics here) -- and speed is not the top speed, or even speed in a sustained dash. Speed here refers to net time taken to go over many hundred Kms in a short span of time (this includes the number of liters of fuel it will burn, number of spares needed for that etc, and hence the logistical trail)

The technological generation remaining same (don't compare tanks 20 years apart) -- a light(er) tank has some inherent advantage over heavier ones as well as some disadvantages. Those are trade-offs which exist within a MBT design space. Just as in A/C space (otherwise IAF would want ONLY Su 30s)

Iit will be T 90 which will take us to RYK.

Don't it need to survive enemy attack to reach RYK? or again its just race

It will try its best to not meet any enemy tanks on the way, that will only slow down the dash. The enemy tanks should have been softened earlier by Combat Heli's, mass of Pinaka's on their staging centers and such like. BTW, even US did exactly the same with Abhrams in Iraq. By the time M1s came to battle, it was already a turkey shoot, pretty much.

However if they have to meet resistance, they are more than match for anything in terms of armor that will come their way.

[Austin]

However if they have to meet resistance, they are more than match for anything in terms of armor that will come their way.

Any information on the known armor thickness/protection offered by Pakistani T-80UD and Bhisma T-90 ? I suppose T-80UD is the best they have.

Do both tanks carry the same gun launched missile and KE rounds ?

[chackojoseph]

does T-90 fit in light tank category? light is about low weight and better speed.

Very important observation. T-90 offers only one advantage over Arjun for being light weight. But, when it comes to speed, psi, etc, it dosen't. Being light, it should "ideally" have those advantages.

[Sanku]

does T-90 fit in light tank category? light is about low weight and better speed.

Very important observation. T-90 offers only one advantage over Arjun for being light weight. But, when it comes to speed, psi, etc, it dosen't. Being light, it should "ideally" have those advantages.

T-90 is a light(er) tank not light tank. Both are MBTs.

Just that their trade-offs are slightly different.

For example

Fuel consumption. T-90S = 1600 litres... combat range = 650km = .40 KMPL Arjun = 1610 litres... combat range = 450km = .27 KMPL ...

Many such tradeoffs can be talked about.