So I see a lot of discussion about the Soviet Union's infamous Kontakt-5 ERA here, which according to many citations rendered an old T-72 impenetrable to modern NATO armaments. In general, our national tank doctrine didn't call for much/any ERA so I don't know too much about it.
One thing I wonder - how does the 'brick' system work? I expected to find a youtube video or something but could not. Basically the question is - when an APFSDS or HEAT round hits an ERA-protected portion of the tank - as seen below - how many of the 'bricks' detonate? One, or two, or all of them? Does it depend on angle of the hit?

Presumably a hit on the glacis will not detonate the turret ERA. But it also seems unlikely that each successful hit detonates just a single brick.
And then - can the tank crew replace their own ERA bricks, or does this require a specialized maintenance team.
It would be interesting to model this in game - perhaps units bearing ERA are impervious to the first significant AP shot in every instance, but not thereafter. Actually, Battlefield 3 models this nicely - if you select Reactive Armor specialization, you shrug off the first tank hit but an engineer can repair your tank and add back on.
Perhaps it could even be a munition - ERA plates left on the tank.
Anyway I'm sure someone with more knowledge of Soviet tank doctrine will be along to correct me sooN!
