Well, T-72B armour was improved on different production batches.
For your example, it may be correct, probably it is of first variants, but since 1989 protection was more than 500 mm for hull and 550-600 mm for turret, or 470-500 mm for 30 degrees.
Given relation of turet-hull protection stated figure of 550-600 mm in relation to hull, 500-550 mm, makes sense (rough difference of 10-20%).
Actually for T-72B figure was, for hull
1985 - Passive armour composition, about 460-480 mm
1989 - 500-550 mm semi-reactive armour composition.
(T-80U with semi-reactive armour composition, 500 mm)
There was some difference with early T-90. It was again improved in T-90A to 600 mm.
Lidsky, I know about armour upgrades, the problem is that - T-72B and T-72BM (1989) have the same insert in special armour cavity - it's ths same somposition whit the same efectivnes. And depend on angle this armour in Ob.184 give between 470 adn 540mm RHA vs APFSDS form base turret armour. Of course with Kontakt-5 it's look mucht better.
And even erly T-90 whit cast turret have Verry simillar insert. It was changed in T-90A whit welded turret.
Now on ERA.
Relikt for T-72B, T-90 gives an increase in protection of 1.4 times, or 250 mm according to Nii Stali.
Hull, about 500-550 mm of T-72B, + 250 mm gives up to 750 mm against APFSDS, or about 1.4 times increase, which corresponds with stated by Nii Stali protection against M829A2.
T-90A, about 600 mm, + 250 mm, or increase of 1.4 times would give 850 mm, same as stated in presentation.
On this case, all stated figures correspond.
It is nosense.
It's the best method counting ERA and its using becuse values gives in that method are most comfortable for estern tanks.
Diffrent method (used in other countries) is depend on fact that ERA cassette reduce some % of penetrator perforation abilities, and after damege and loose some abilities penetrator must overpass basic armour. Counting basic armour + mm from ERA is not really relevant, but it's very comportable due to marketing resons.
Exampe:
Lest sey that in my personal opinion T-90A basick armour (without hevy ERA) is about:
for 840mm LOS about ~650mm RHA (lets say 600mm RHA for about 750mm LOS)
for 650mm LOS about ~500mm RHA.
Those values are big (maybe to bigg) but I have resont to stay with those values.
Enemy:
DM63 L-44 650mm RHA 2000m
DM53 L-55 750mm RHA 2000m
And now we have two diffrent metods counting ERA efectivness:
1) Yours: 600mm x 1.4 = 840mm RHA (240mm RHA "added" by ERA) in fact LOS is fluent for turret front for ) degree so whit this 1.4 the biggest value will be 910mm RHA the lowest- 680mm RHA but this give us problem that with "constans" ERA 1.4 value this "mm RHA" are fluent.
2) Using by me - ERA can reduce perforation capabilities - it's some % of penetrator abilities and its diffrent for difrent rods, ange of hit, etc. For example Ukrainian Knife can reduce on about 90% when APFSDS hit in this upper part of module consisti of three knife cassette layers. But hit in lower part incarase lower value -only about 60-70%. The worse scenario is for single layer for hull Knife module when hit in down part of ERA casette give us value under 50%.
The same for Relikt and Kontakt-5. Old Kontakt-5 can deal whit modern rods only in about 15%, it's upgraded version whit diffrent layout have fluent efectivness about 20%. For Relikt is given valur 50% in the best scenario and about 25-30% in whorse. This values have more sense then placed 1.4 in all time. It's difrent method and IMHO rather better.
In that case T-90 whit 600mm RHA on turret have still this 600mm RHA but atacking DM-53 will lose form 25 up to 50% perforation posibilities. So finnaly it will be from 560mm to 375mm RHA perfration after hit in Relikt casette.
You did not understood. It is not correct to talk about weight effectiveness, when protection which you measure will depend on volume (thickness).
Material with several times better weight efficiency may be more voluminous.
Rather you wold like to say that material with several times better weight efficiency can by placed in thinner layer whit bigger armour protection, but it's not work in that way about Burlinghton
Weight comparison is irrelevant, especially if turret of Leopard 2 is much bigger and has much more armour volume.
Yes, and no. Yes becouse when front area in m2 is the same for both tanks (Leo2A4 and T-72B -yes, I know, but it's true both have the same 4,5-4,7m2) then turret sides in Leo-2A4 protected to hal its lenght give bigger volumen.
But if you consider that 8.900kg Burlinghton armour whit mass efectivnes like given in this article for 1978r (1,5 vs KE, 3x CE) is equal to 13.350kg vs APFSDS and 26700g vs HEAT you can see how diffrent protection it can be...even if volumen (due to turret sides) is slighty (20-24%) bigger in Leo2A4...
BTW: nobody says that 1,5 and 3 is correct for Leo-2A4 it can be bigger values becouse tank for 1985 should have better armour then from 1978...
This is semi-reactive armour which uses energy of projectile to destabilise it.
Effectiveness will depend on angle of incidence against plates. It gave already good level of protection against Kinetic and cumulative rounds. Effect of destabilisation will be much higher in combination with ERA.
Those reflecking platas in T-72B are primitive IMHO it's not even NERA as I said - it's work like bulging armour: eacht module is 30m thick, when firs RHA layer (21mm thick) is hit and penetrated by initially "blunt" (by front cast steel armour) penetreto, is transfering energy by 3mm thick rubber to 6mm thick hight plasticy RHA plate. This plate during bulging give back energy into penetator area and change a little position so it can bent a little penetrator. It's efectivness is the biggest on little angle - close to 10-20 degree - when ange is bigger then it's efectivness is smaller but in that case more then 3 modules try to damege penetrator. So finnaly for this bigger angle protection is not many worse. After those layers damage and little bent (and blunt) penetrator hit 45mm thick HHS plate so older partial penetrator can be broken and shorter penetrator can be bent to mucht to overcome inner layers. But longer dhen DM23 penetrator should be able to overcome this armour In fact those armour it's definetly not hig-teh. It's less advanced then ERA or Bulinghton, and it's efectivness is mucht worse. But its "compensate" by hilarious thick cast steel plate. Of course I had read on NI Stalii pages about that, and in other sources -but this armour is not impresive, and not modern at all...
Semi-reactive armour of T-80U is based on different principle, with polymer filler actuating as quasi-liquid due to inciding energy, waves generated by round will be reflected on armour, and will destabilise round.
Yes, it's slighty more modern.
Difference of effectiveness of such armour is about 5-10% (roughly corresponds with T-80U hull, more than 500 mm, and T-72B hull, more than 550 mm). Reflective layers would give better performance.
As I remember on NI Stalii pages - solution from T-80U have bigger efectivness against HEAT... And in T-80U hull there is no solution like that so compare to hulls in T-72B and T-80U is pointless. In fact there is big difrense between hull layout in T-80U and T-72B and ironicly it's not good for T-72B...
