Main Battle Tanks and Armour Technology

[Damian]

Well it's hard to say, but yeah, the inclination gives additional headache to calculate these things.

 

[hest]

BTW -if Lidsky describe correctly those German armour from 1970s. then it looks that:

First is correct. But fourth plate of second is 5 mm rubber and 3 mm steel, not 40 (my fault).

About test result:

6 blocks placed at 60 degrees from vertical.1 - multilayer structure, 35 mm steel plate with hardness between 1430 - 1630 MPa + 5 mm rubber layer + 3 mm medium hardness steel plate. 2- 25 mm steel plate of 1630 - 1730 MPa + 5mm rubber + 3 mm medium hardness steel. 3, 4, 5 - same as 2. 6- 50 mm steel plate of maximum 1220 MPa.

Simple translation:

Perforation of first block caused bulging of thin metal plate. During process, bulge of area with perforation of cumulative jet shifted towards the direction of the jet resulting in a moment when the jet ceased to incide against perforation, but cut a dome formed by the convexity of the bulge from center of the perforation to the periphery, resulting in double penetration of the metal plate. As noted by German specialists, this caused significant reduction of the cumulative jet.

Composite with steel plates and inert filler is employed in armour of Leopard 2 (...).

Those inclination angle can be not in vertical but hotizontal. In Leopard-2A4 turret verticaly it is 90. but horizontaly - 60 degree. IMHO special armour in frotnal part is sloppeed at 60 degree.

60 degrees from vertical, as feature of this kind of armour, steel and inert low density. For ceramic optimal angle is different.

Becouse it's true.
But You completely neglecting the fact that Burlinghton style armour have some mass efficiency in kg armored steel (RHA). And when we included that fact then density vs KE is the same, in HEAT is mucht better.
In T-72B armour kg ofthe cast steel is 0.9 kg as RHA plate. + two 741kg weight NERA panells. In Leopard2 eacht 1 kg special arour works like at lest 1,5kg RHA vs APFSDS and 3kg vs HEAT. And this is diffrece.
If You want to talk about volument and area - important is only frontal area in m2 becouce Burlinghton is alway slighty thicker then other solutions. So important is kow many KG will be for m2 frontal protection. And result is not so very good for T-72B:

You have protection coefficient in function of mass against KE and HEAT, and proper mass coefficient in function of density (mass/volume).

Volume is important for overall weight (more volume, more limitation of density in general) so if Leopard 2 volume is 1/4 greater atleast, it is an argument supporting that density is lower. First.

Second; what percentage of armour volume is taken by filler, and what by homogeneous steel ? In T-72B or T-80... there is greater relation of steel, so density or mass coefficient should be greater.

Third; mass coefficient of cast steel, and protection coefficient of it's mass is close to 1, so in thickness, volume it is notably greater protection against KE than composite filler.

In general: Higher density allowed by less overall volume. Greater part of steel <=> higher density => higher protection against KE.

 

[militarysta]

Damian if You want to count somthing try to count this model:


IMHO this model is strange a lot of armour plates is here:

40mm RHA (front plate) after 500mm (special armour) whit one 50mm RHA plate after that we have: 40mm RHA + 40mm RHA + 40mm aramid/kevlar + 50mm ceramisc/polymer +50mm ceramisc/polymer + 30mm HHS +30mm HHS +30mmHHS. It gives 90+80+90 = 260mm of RHA/HHS plates + 5 NERA plates inside "special armour". It weight a lot.

btw -for fun -

 

[militarysta]

btw -for fun -
http://www.dejawolf.com/steelbeasts/armourscience/TEvalues.html

vs KE:
40mm RHA + 50mm RHA + 52mm RHA + 52mm RHA + 0mm +54mm +54mm+ 39mm RHA +39mm RHA +39mm RHA
= 420mm RHA + 5 NERA layers (again 140mm RHA plates and aditional ruber)
So in theory only RHA plates is 420mm without NERA and 560mm with NERA (of course NERA work in diffrent way)

vs HEAT
40mm + 50mm + 52mm +52mm + ?? + 75 +75+ 39mm RHA +39mm RHA +39mm RHA =
461mm RHA + 5 NERA layers. (again 140mm RHA plates and aditional ruber) = 600mm RHA plates (of course NERA work in diffrent way)
IMHO those model is to simple and to far far away from known facts about Burlinghton be real in Leopard-2 armour

 

[Damian]

A - 50mm HHS
B – 35mm HHS + 5mm Rubber + 3mm SHS + 50mm Air + 25mm HHS + 5mm Rubber + 3mm SHS + 35mm Air + 25mm HHS + 5mm Rubber + 3mm SHS + 35mm Air + 25mm HHS + 5mm Rubber + 3mm SHS + 35mm Air + 25mm HHS + 5mm Rubber + 3mm SHS + 50mm Air + 50mm HHS
A – 50mm HHS
A – 50mm HHS
C – 60mm Kevlar
D – 80mm AD-97
D – 80mm AD-97
E – 50mm RHA
E – 50mm RHA
E – 50mm RHA

HHS – 1,3 TE vs KE/1,3 TE vs CE
SHS – 1,2 TE vs KE/1,2 TE vs CE
AD-97 – 0,97 TE vs KE/1,5 TE vs CE
DU – 1,3 TE vs KE/1,5 TE vs CE
RHA – 1 TE vs KE/1 TE vs CE
Air – 0 TE vs KE/0,26 TE vs CE
Rubber - ? TE vs KE/? TE vs CE

A - 50mm HHS – 65mm RHAe vs KE/65mm RHAe vs CE

B – 35mm HHS (45,5mm RHAe vs KE/45,5mm RHAe vs CE) + 5mm Rubber (? vs KE/CE) + 3mm SHS (3,6mm RHAe vs KE/3,6mm RHAe vs CE) + 50mm Air (13mm RHAe vs CE) = 49,1mm vs KE/62,1mm vs CE

+ 25mm HHS (32,5mm RHAe vs KE/32,5mm RHAe vs CE) + 5mm Rubber (?) + 3mm SHS (3,6mm RHAe vs KE/3,6mm RHAe vs CE) + 35mm Air (9,1mm vs CE) = 36,1mm vs KE/49,1mm vs CE

+ 25mm HHS (32,5mm RHAe vs KE/32,5mm RHAe vs CE) + 5mm Rubber (?) + 3mm SHS (3,6mm RHAe vs KE/3,6mm RHAe vs CE) + 35mm Air (9,1mm vs CE) = 36,1mm vs KE/49,1mm vs CE

+ 25mm HHS (32,5mm RHAe vs KE/32,5mm RHAe vs CE) + 5mm Rubber (?) + 3mm SHS (3,6mm RHAe vs KE/3,6mm RHAe vs CE) + 35mm Air (9,1mm vs CE) = 36,1mm vs KE/49,1mm vs CE

+ 25mm HHS (32,5mm RHAe vs KE/32,5mm RHAe vs CE) + 5mm Rubber (?) + 3mm SHS (3,6mm RHAe vs KE/3,6mm RHAe vs CE) + 50mm Air (13mm RHAe vs CE) = 36,1mm vs KE/49,1mm vs CE

+ 50mm HHS (65mm RHAe vs KE/65mm RHAe vs CE)

A – 50mm HHS – 65mm RHAe vs KE/65mm RHAe vs CE
A – 50mm HHS – 65mm RHAe vs KE/65mm RHAe vs CE
C – 60mm Kevlar - ?
D – 80mm AD-97 – 77,6mm vs KE/120mm vs CE
D – 80mm AD-97 – 77,6mm vs KE/120mm vs CE
E – 50mm RHA
E – 50mm RHA
E – 50mm RHA

Total = 758,7mm RHAe vs KE/908,5mm RHAe vs CE

Funny though, LOS thickness of such array is 935mm, so the model is rather incorrect for Leopard 2.

A rough estimation for your drawing @militarysta, although I do not have TE values for Kevlar and I assumed used materials for the cheaper and mostly used ones. And of course if did not done any mistakes.

IMHO those model is to simple

I agree, it seems that my opinion it was most probably developed for passive armors.

I don't know how to make and include there dynamic interaction between NERA and projectile.

 

[militarysta]

Yyyyy
thickes of layers is to big:
A - 50mm HHS 46mm
B – 35mm HHS + 5mm Rubber + 3mm SHS + 50mm Air + 25mm HHS + 5mm Rubber + 3mm SHS + 35mm Air + 25mm HHS + 5mm Rubber + 3mm SHS + 35mm Air + 25mm HHS + 5mm Rubber + 3mm SHS + 35mm Air + 25mm HHS + 5mm Rubber + 3mm SHS + 50mm Air + 50mm HHS
A – 50mm HHS 46mm
A – 50mm HHS 46mm
C – 60mm Kevlar [57mm/b]
D – 80mm AD-97 57mm
D – 80mm AD-97 57mm
E – 50mm RHA 34mm
E – 50mm RHA 34mm
E – 50mm RHA 34mm

Thos value are for 60 degree. Has it change a ot?

 

[Damian]

I have enough of making calculations for today...

A - 46mm HHS – 59,8mm RHAe vs KE/59,8mm RHAe vs CE

B – 35mm HHS (45,5mm RHAe vs KE/45,5mm RHAe vs CE) + 5mm Rubber (? vs KE/CE) + 3mm SHS (3,6mm RHAe vs KE/3,6mm RHAe vs CE) + 50mm Air (13mm RHAe vs CE) = 49,1mm vs KE/62,1mm vs CE

+ 25mm HHS (32,5mm RHAe vs KE/32,5mm RHAe vs CE) + 5mm Rubber (?) + 3mm SHS (3,6mm RHAe vs KE/3,6mm RHAe vs CE) + 35mm Air (9,1mm vs CE) = 36,1mm vs KE/49,1mm vs CE

+ 25mm HHS (32,5mm RHAe vs KE/32,5mm RHAe vs CE) + 5mm Rubber (?) + 3mm SHS (3,6mm RHAe vs KE/3,6mm RHAe vs CE) + 35mm Air (9,1mm vs CE) = 36,1mm vs KE/49,1mm vs CE

+ 25mm HHS (32,5mm RHAe vs KE/32,5mm RHAe vs CE) + 5mm Rubber (?) + 3mm SHS (3,6mm RHAe vs KE/3,6mm RHAe vs CE) + 35mm Air (9,1mm vs CE) = 36,1mm vs KE/49,1mm vs CE

+ 25mm HHS (32,5mm RHAe vs KE/32,5mm RHAe vs CE) + 5mm Rubber (?) + 3mm SHS (3,6mm RHAe vs KE/3,6mm RHAe vs CE) + 50mm Air (13mm RHAe vs CE) = 36,1mm vs KE/49,1mm vs CE

(Total = 144,4mm vs KE/196,4mm vs CE)

+ 50mm HHS (65mm RHAe vs KE/65mm RHAe vs CE)

A – 46mm HHS – 59,8mm RHAe vs KE/59,8mm RHAe vs CE
A – 46mm HHS – 59,8mm RHAe vs KE/59,8mm RHAe vs CE
C – 57mm Kevlar - ?
D – 57mm AD-97 – 55,29mm vs KE/85,5mm vs CE
D – 57mm AD-97 – 55,29mm vs KE/85,5mm vs CE
E – 34mm RHA
E – 34mm RHA
E – 34mm RHA

Total = 650,48mm RHAe vs KE/775,9mm RHAe vs CE

Array LOS thickness = 826mm

Still lack of some TE values + lack of dynamic interaction between NERA and projectiles. Any ideas about TE values for rubber and kevlar?

 

[JBH22]

last one for today

The top 10 MBT list from Military today

Top 10 Main Battle Tanks | Military-Today.com

 

[Damian]

last one for today

The top 10 MBT list from Military today

Top 10 Main Battle Tanks | Military-Today.com

Such Top 10 lists are funny. And mostly useless.

 

[JBH22]

Such Top 10 lists are funny. And mostly useless.

Agreed but still given that human mind is geared towards comparison so we get list like this

Btw how do we quantify tank crew training is it like pilots who get it in hours any idea on this?

 

[Damian]

Agreed but still given that human mind is geared towards comparison so we get list like this

Comparision yes, but proper comparision can't be simplified to the level of absurd, like that particular list you posted. Not to mention that general conclusion of properly made and detailed list would be that all these machines are more or less comparable in general characteristics, and noone would be interested in such list... maybe perhaps only such "tank nuts" like me or Militarysta.

Btw how do we quantify tank crew training is it like pilots who get it in hours any idea on this?

AFAIK it is similiar, although Militarysta should have more detailed informations how Germans do this, it should be standard for NATO.

 

[militarysta]

lack of dynamic interaction between NERA and projectiles. Any ideas about TE values for rubber and kevlar?

here:

In the following
we will refer to this kind of armor as reactive armor (RA). The basic material of our investigations
was the energetic binder glycidyl azide polymer (GAP). The physical and chemical
properties of GAP reported in personal communication [1] and literature [2], [3]
made it a hopeful candidate for our purpose. Various mixtures of GAP and other materials
have been tested. It turned out that, for the use as interlayer material in reactive armor
sandwiches, it is necessary that there is some content of a high energetic material like
RDX in the mixture in order to get an armor with a sufficiently high protection power.
(...)
For the tests medium
caliber shaped charges were fired against inclined sandwiches which consisted of two
2 mm thick mild steel flyer plates and an intermediate 8 to 12 mm thick layer of the material
or combination of materials to be tested. The sandwiches had a lateral size of 200 mm
× 50 mm. The firings were done at a standoff distance of 2 calibers and the angle of inclination
of the sandwich targets was 60 degrees.
(...)
The 73 mm shaped charge employs a conical copper liner with a 60° apex angle and
an apex diameter of 64 mm. Its wall thickness is 1.5 mm. The tip velocity of the shaped
charge jet was 8.1 km/s and its reference penetration depth into C 60 steel at a standoff of
2 calibers was measured to be 362 mm.
(...)
As already mentioned above the test vehicles of our search for an effective reactive armor
material were sandwiches of the type 2 mm steel / X / 2 mm steel, X being the interlayer
to be tested.
(...)
In case of an inert interlayer the plate motion is caused by the elastic pressure transferred
into the interlayer by the jet. Then the plate motion is only a bulging of the plates. If
the interlayer is a high energetic material the plates are driven apart by a detonation and
they are forced really to fly. In case of a less energetic interlayer both bulging and flying
of the sandwich plates, the latter caused by a chemical reaction with an accompanying gas
production, may become important for the distortion of shaped charge jets.
The tested mixtures of GAP are included in the list below.
– GAP= Glycidyl azide polymer + Desmodur N 100
– GAP+ CaCO3
– GAP+ GZT (GZT = Guanidinazotetrazolat)
– GAP+ 20% RDX
– GAP+ 70% RDX
All of these mixtures were prepared by the Fraunhofer-Institut für Chemische Technologie
(ICT), Pfinztal, Germany.
Because pure GAP is a liquid with an oily consistency for our purpose it was hardened
with the hardening agent Desmodur N 100. In the following GAP + Desmodur is simply
called GAP. Its density was ρ=1.27 g/cm3. The densities of the other mixtures were
ρ=1.03 g/cm3 (GAP + CaCO3 and GAP + 20% RDX) and ρ=0.97 g/cm3 (GAP + GZT and
GAP + 70% RDX). All mixtures had the consistency of soft rubber and could be cut with
a sharp knife. The thickness of the interlayers built of these mixtures was 10 mm.
Furthermore experiments with combined interlayers of an 8 mm thick rubber or
10 mm thick GAP layer and an additional 1–2 mm thick layer of the high explosive Dottikon
were carried out. Dottikon is a composition of 85% PETN and 15% binder. Its density
is 1.4 g/cm3 and its detonation velocity is about 7000 m/s. At the experiments with
two intermediate layers the Dottikon layer was directed towards the shaped charge.
At our very first experiments sandwiches with 8 mm thick rubber interlayers (Perbunan,
density ρ=1.45 g/cm3) were tested. These sandwiches with a fully inert interlayer
served as a standard target for the evaluation of the later tested sandwich armors.

So as we can see, even single simple NERA layer can reduce about 20% SC warhed. But those NERA in erly german model looks diffrents - first plate is thick, so it's closer to ENIGMA armour or...T-72B.
IMHO model described by Lidsky can show rejected german solution before gettng akcess to the Burlinghton (1976).

 

[Damian]

Paul Lakowski wrote -

1.3.6.3 Non Explosive Reactive Armor NERA
A variation of this theme is Soviet 'BDD' or 'Brow armor'. This is a thick armor added to the front turret and glacis of older tanks. The bulk of thethickness is rubber with a few thin [5mm] mild steel plates mounted freely.
When this is struck, the kinetic energy of the rod or jet is re-transmittedthrough the rubber to the mild steel plates, which bulge in the samemanner described above.
The T-55 BDD glacis thickness is 150mm with30mm RHA casing and alternating layers with 4 x 5mm mild steel sand-wiched in between 100mm rubber. The effectiveness should be 3[RHA] + {2x 0.8{mild steel] } + 10 x 0.1 [rubber] divided by 15; that's a theoretical TE[Thickness effectiveness] of 0.37. But the actual TE of BDD is 0.44, or a17% increase in effectiveness.
Steve Zaloga indicates the T-72B turret hasNERA type armor, utilizing Aluminum instead of mild steel.
The insertshould have a TE of 0.41 KE and 0.34 HEAT. similar to the figures for theBDD on the T-55/62. T-90 turret has an improved NERA type armor as well.

But this is old and might not be 100% accurate.

 

[militarysta]

Enigma NERA-style (very prymitive) armour:

 

[militarysta]

Anyway -it's really interesting how good protection will have Leopard-2 even If "we" put in armour quite primitive solution from erly 1970 -without conectiong with Burlinghton armour.

Damian estimatous give us vs. KE 456mm RHA + 5 NERA layers (phisical thickenss like 144,4mm vs KE but of course whole protection accoding to active workin NERA will be better). So in that shape erly leopard-2 cauld have mucht more then 500-550mm vs KE.
And agains HEAT we have at least 517mm RHA + 5 NERA layers (phisical thickenss like 196,4mm vs CE but of course whole protection accoding to active workin NERA will be better). So in that case erly leopard-2 can overpas 700-800mm vs HEAT.
And we are talking about solutions form erly 1970's...
It's interesting when we compare those values whit known Burlinghton in conjunction with erly MBT-80 program:
previously MBT-80 had assumed protection as: 430mm vs KE and 585mm vs HEAT, incarase HEAT protection up to 850mm RHA resulted in a decrease KE protection to 405mm, in 1978 assumed MBT protection as 540mm vs KE and more then 600 vs HEAT. Interesting....

btw: Lindsky, maybe You took that armour describe from that source? :
Zaszczita tankow, red. W. A. Grigorian, Moskwa 2007, s. 118–126

 

[Damian]

@militarysta, the problem is that we use simplified models that are based on assumptions, we do not know exact composition, where each different material is placed, how all these materials interacts with eachother and projectile during penetration process, as well as these simplified models do not include as I said earlier, the efects cause by NERA working mechanism.

This means very big variability of results during calculations, which means every single result might very far or very close to reality, which further means, any such estimation, being interesting is also completely futile.

 

[militarysta]

@militarysta, the problem is that we use simplified models that are based on assumptions, we do not know exact composition, where each different material is placed, how all these materials interacts with eachother and projectile during penetration process, as well as these simplified models do not include as I said earlier, the efects cause by NERA working mechanism.

This means very big variability of results during calculations, which means every single result might very far or very close to reality, which further means, any such estimation, being interesting is also completely futile.

Indeed, but IMHO importan is smth. diffrent - those funny numbers (it's rather fun/joy) proof that even taking only psyhical thickenss of layers in model based on:
a) some ery 1970's german NERA armour (as "special armour")
b) known stand armour for ammo test (but whit thickenss amazing consider whit Leopard-2 LOS...)
protection oofer is much bigger then most of "super duper secred russian/polish/hungarian steel instytiude" post in some older articles and books. Bot of us know tat russian and polish older (more then 10-15 yaers) estimatous give Leopard-2A0 around 400mmvs KE. Now it's clearly visible that (again) those value was understimated.

 

[Damian]

Because these institutes also need to provide a, something we can call "propaganda for state internal purposes". I think the only ones who keep real estimations are people from GRU, and GRU would definetely not want to others knew what they know, and especially not disclose that their estimations might be close to reality. And GRU have definetely complete authority over R&D institutes like NII Stali.

Same goes for CIA, untill the end of cold war, CIA didn't released their estimations based on intelligence work (USMLM, BRIXMIS etc.). I am 100% sure that Army Research Laboratories have very good data about protection of the soviet and ex soviet tanks, afterall they tested T-84's, T-80U's and god only knows what else. But they do not release such informations, and there are good reasons to not release such informations... it is truth for any state.

 

[hest]

btw: Lindsky, maybe You took that armour describe from that source? :
Zaszczita tankow, red. W. A. Grigorian, Moskwa 2007, s. 118–126

Yes I have that book, it is good publication of various authors, many from NII Stali and other specialists providing broad information and published by state politechnical university (МГТУ им Баумана).

Anyway -it's really interesting how good protection will have Leopard-2 even If "we" put in armour quite primitive solution from erly 1970 -without conectiong with Burlinghton armour.

Damian estimatous give us vs. KE 456mm RHA + 5 NERA layers (phisical thickenss like 144,4mm vs KE but of course whole protection accoding to active workin NERA will be better). So in that shape erly leopard-2 cauld have mucht more then 500-550mm vs KE.
And agains HEAT we have at least 517mm RHA + 5 NERA layers (phisical thickenss like 196,4mm vs CE but of course whole protection accoding to active workin NERA will be better). So in that case erly leopard-2 can overpas 700-800mm vs HEAT.
And we are talking about solutions form erly 1970's...
It's interesting when we compare those values whit known Burlinghton in conjunction with erly MBT-80 program:
previously MBT-80 had assumed protection as: 430mm vs KE and 585mm vs HEAT, incarase HEAT protection up to 850mm RHA resulted in a decrease KE protection to 405mm, in 1978 assumed MBT protection as 540mm vs KE and more then 600 vs HEAT. Interesting....

Whole described armour thickness is more than 700 mm and it corresponded with tank armour. This principle is present in armour of Leopard 2 but not only. Their composite from Chobham employs ceramics and they are also present in Leopard. From what you showed it is possible that main block (500 mm...) is bulging armour, backed by ceramic structure (instead of steel plates), but it is only an idea.

Efficiency of this armour, semi-active effect ,etc are all well described (if you have access to publication), so no need for self made estimations.

It is also stated that later KE protection improvement of such bulging armour came from use of heavier material, DU encased in steel, which is sgnificanlty heavier armour.

 

[Damian]

It is also stated that later KE protection improvement of such bulging armour came from use of heavier material, DU encased in steel, which is sgnificanlty heavier armour.

Not only DUA, also WHA, there is even possible combination of both. And yes it is significantly heavier armor. However the original Burlington weight also increased.

The original XM1 weighted 52 metric tons, production M1 weighted 54 metric tons, M1IP 55 which was approx 1 metric ton of armor improvement, M1A1 weighted 57 metric tons, increase in weight was mostly from a bigger heavier gun, but all later improvements were significantly heavier, M1A1HA weight was around 60 metric tons or more even, the newest variants are weighting 63 metric tons, this is approx 9 tons more than original production standard M1, and most of this weight (probably approx 80-90% - for example under armor gas turbine APU weight's only 205kg and diesel APU weight's 190kg, electronics are also lightweight) comes from armor improvements.

The question is how it is arranged in the array.