That's not true. Most of what has been claimed about the performance of Nozh and Duplet is propaganda (90% reduction of APFSDS penetration for example). Just take a look at actual penetration values of linear shaped charges and the size of Nozh/Duplet inserts: they cannot actually penetrate even with optimum standoff. When an APFSDS hit Nozh/Duplet only a sinlge (!) linear shaped charge might have optimum standoff, the rest will perform even worse.
Yes, such performance is not possible to achieve with shaped charges, howewer, description given in open media of Nozh working method is not correct, there are other components, effects contributing to damage of penetrator. Some material for thought (fast translate):
"Now, regarding "Nozh." ERA. The cumulative "Knives" is not news for ERA developers. Back in the early 70s, this principle is being followed by NII Stali in cooperation with the Kharkov design bureau. Then, for this method of protection is not achieved acceptable performance. One of the reasons -
too small a distance at which the linear shaped charges have shown the cumulative effect of a knife.
This distance is less than half the size of cumulative cavity, ie several centimeters. At large distances, the cumulative knife, "blurred" and its efficiency drops sharply. Therefore, when metal is cut by the elongated hollow charges, they are placed substantially adjacent to the metal. Another reason for purely constructive plan. To form a flat "knife" is required for the initiation of a complex structure elongated charge. To form a "proper knife" by spot detonator cord is not possible.
Another thing is that the
actual design of DZ 'Knife' is different from the one that the authors draw in the open literature and also the effect of "knife" in
it contains other components which, in our opinion, ensure the effectiveness of a given complex. The whole question - what is this efficiency. But here, too, while many uncertainties, especially when there is a comparison of "Knife" and "Relic". Data on RELICT is based on its experimental evaluation of modern ordnance (Svinets-1, Cornet, Vampire, etc.). "Knife," according to the authors also tested the likes of ammunition, but in the photo, for some reason justifying an effect only shows outdated BPS develop the 50s, but the Bulgarian tandems, fight which is much easier than with the above.
Exactly the same doubts arise about the high performance "Knife" in relation to the tandem ammunition and percussion cores. "Knife" pure this efficiency can not provide due to construction.
Alas, a serious analytical articles sometimes have to sift through advertising on the actual state of affairs."
Nozh/Duplet can only damage/weaken a penetrator and not destroy it as claimed by btvt.narod.ru. The Czech "Explosively Formed Axe" active protection system (where the charges are fuzed by computer and thus can be detonated closer to the ideal point) manages to reduce the penetration of APFSDS by 20 - 30% (which is essentially Kontakt-5 performance level against 1980s APFSDS); not 90%.
Duplet has the advantage of using two layers - but that's it. It is not going to resist better against segmented penetrators, it is not going to magically protect even APCs against tank ammunition. It is not "the oly reliable type of ERA".
There is not evidence which could confirm Nozh advertised claims, in tests neither theoretical explanation (unlike Kontakt, Relikt, of which there is good information in media), just advertisement. But it does not exclude that it could be an effective protection though.
The possibilities of segmented construction against composite and reactive armour were known for decades already and they are not new, nor any breakthrought, it is not as if they were left apart during Relikt developement. They can be effective in the sense that they do not suffer such a drastic performance reduction after interaction with ERA, yes, this is agreed, but they are still subject of inevitable damage with loss of lenght, leading part which does not participate in armour penetration and some destabilising effect, especially against two reflected plates. Even DM63 has notably degraded performance after test with some ERA. What is important is
combination of main composite and reactive armour. While that round could be effective against legacy tanks with Relikt upgrade such as T-72B, T-80.. against modern target it would be more dubious.
About modernised T-90, Sienko (UVZ) in interview stated that it has a perspective for period of next ten years.
The construction of Relikt is still pretty unkown, so is the construction of Kaktus. Rolf Hilmes said that Kaktus would use much heavier flyer plates - this might have been an attempt to counter segmented penetrators (i.e. if the plate is too thick for one segment, it will reduce the penetration of the APFSDS after ERA compared to Kontakt-5). Relikt might also use some features making it more resistant to modern non-monobloc rounds, they could for example try using a multi-layer flyer plate or something like that. It is not very clever to describe Relikt as "obsolete" when it is still unkown how it works/looks.
Indeed, what was pursued with serious modernisation programmes is not Relikt but a different ERA construction and working principle from multi-layer or double plate interaction. This is a new reactive armour element implemented in T-72B, T-90 upgrade (Burlak) consisting of modules including large dynamic elements. In simple form, this principle makes use of a plate of large surface and great thickness, using greater amount of explosive to preserve great velocity and increase energy directed against projectile. This combination allows to destroy segmented penetrators by projecting on the whole rod and to achieve anti-tandem properties. Near future howerer is with reactive armour using non-explosive energic material.
From related KBTM patent
image
Burlak ERA
