Recently discovered that the external composites on the challenger 2s turret are nullified by tandem HEAT which makes absolutely no sense based upon the nature of NERA composite armour in game and IRL( justification for IRL below. However, even if unconvinced by my argument, my point still stands about the inconsistency of NERA in game). If Developers had chosen to make Tandem effective against NERA due to its effectiveness against ERA and the similarity between their mechanisms, why is it the case that all internal NERA elements are unaffected by a tandem warhead. Especially the Challenger 2 since it is known that both the internal and external composites are variations of the Dorchester composite array so this inconsistency against tandem threats makes no sense.
One could argue that since NERA works in a similar manner to ERA, in which the sandwiched plates are projected in opposite directions, a tandem warhead would have similar effect in reducing the effectiveness of NERA against a cumulative charge. However, in the following images it is evident that the NERA plates are still in motion after perforation by a jet or a kinetic threat.
Using the following source and previous images for my justification on NERAs effectiveness against tandem:
With a detonation delay of 90x10^-6 seconds after initial charge, 26x10^-6 seconds after the initial charge interacts with the target, and travel delay of 40x10^-6 seconds we conclude that the secondary Jet begins interacting with the NERA array 64x10^-6 seconds after initial detonation. We can clearly see from the previous images, by the time the secondary charge begins interacting with the NERA, the Nera plates would still be in motion and therefore still have severe effects upon the Secondary charge of the Tandem warhead resulting in likely close to perfect efficiency against a tandem threat. This argument is further supported by the fact that NERA arrays will feature more than one NERA element so once the much weaker initial charge is defeated all following elements will have normal efficiency against the secondary charge. It is also worthwhile to note that the Abrams, Merkava and other western tank designs (which AFAIK both feature a majority NERA composite array) are all still prevalent and remained unchanged after the development of Tandem munitions implying that the arrays remained effective against these munitions. Any documented changes to array composition of these tanks all mention the addition of high density materials to defeat high energy kinetic munitions, with little mention of tandem threats. And in the challengers 2s case they replaced the ERA on the lower plate with a NERA array specifically to defeat tandem charges which further supports its effectiveness against tandem (especially since it is the exact same composite design that is being nullified by tandem threats on the turret sides)
Additionally, the external composites also seem to not increase in protection at higher angles of impact against kinetic threats, I feel that I don’t even have to argue why this makes no sense at all. But I will just in case for both NERA and purely composite threats:
L23A1 against TES and normal CR2 at 60 degree impact angle
The most obvious justification is the increase in effective thickness of the array that the projectile has to interact with. However for NERA arrays it is even more important since the angle of impact determines how the penetrator interacts with the array. At non zero degree impact angles the NERA plates will be able to impart lateral forces upon the penetrator resulting in destabilisation and changing the impact angle of the penetrator, severely reducing its ability to defeat the overall array.
Note: found that the issue is not only prevalent on the challenger 2 but also the Ariete PSO and I worry it will be the same case for the leopard 2 PSO.