Finnaly, my idea about Leopard-2A5 armour protection in circa 1994.
Of course it's only mi idea and based on misty assumptions
The red part is NERA modules:
N1-A and N1-B are two layers of the outer wall NERA modul. Each thickness about ~30-40mm, and inclined at an angle 20. starting from the longitudinal axis - so LOS of the outer wall will be 2x 87-110mm (180-220mm).
N2-A and N2-B are down -outer layers of NERA modul. Inside NERA module are two triangular NERA plates - N3-A and N-3B each one about 40mm thick. Always for any angle and place APFSDS or HEAT jet hit two NERA layers.
As I said - polish simple NERA:
is able to stop (whit spall-linear) HEAT warhed whit slighy more then 300mm RHA perforation if jet hit two layers whit optimum angle. So this german ones shoud offer at last that kind of protection (or better). In "Disturbance of Shaped Charge Jets by Bulging Armour" pdf SC (HEAT) lost about 30% (or more) after hit in one layer of simple NERA. We can see that on NERA panel surface are some kind of "incision" or perforation - propably this NERA pannel are made in that way to save some protection possibilities after one hit and this "incision" are made to stop overgrown "bulging" reaction, or just cracks in SHS plates. One NERA module weight 500kg, and can be veryquickly and easy replaced on field.
After NERA module we have main armour - the whole LOS is 840-850mm thick. The layers:
A - 40mm RHA plates whit HB >550 (external wall Leo-2 turret)
B - 500mm "special armour" (no idea what kind of "sepcial" is this it can be Burlinghton style, or internal NERA)
A - 40mm RHA plates whit HB >550
A - 40mm RHA plates whit HB >550
C -about 40-50mm thick propably some kind of kevlar or aramid layer to cath crack parts of tha last "A" plate
D -something 50mm thick in my opinion it should be ceramics layer
D - second 50mm layer
E - 30mm of RHA plate whit rather bigger plasticity and HB less then 440HB.
E - 30mm of RHA plate whit rather bigger plasticity and HB less then 440HB.
E - 30mm of RHA plate whit rather bigger plasticity and HB less then 440HB.
So this model include ~120mm RHA plates with hight HB, 500mm "special armour", about 50mm kevlar/aramid, 100mm ceramics, and 90mm RHA inner plates.
Some rumors preach that LKEI (DM43) whit perforation 560/620mm RHA for 2000m was not able to perforate this main armour, and even not achive inner ceramics and RHA layers (D and E layers on draw). So this model ( after adding these layers) should offer protection bigger then 650mm RHA vs APFSDS in whorse scenario. What is suprising consistent whit greek Leo-2A6HEL turret test when israeli CL-3143 was not able to perforate those armour. CL-3143 have about 650mm RHA for 2000m. When we add those NERA pannels protection shoud easily exceed 700mm RHA vs KE.
Protection against HEAT is difficult to estimate - NERA module shoud neutralize a least two precursors in modern HEAT warhead, or neutralize one precursor and reduce at about 20-30% main SC. Main armour offer pretty god protection against CE becouse hight HB in RHA doubles its thickness so there is about 380-400mm RHA vs HEAT, and 100mm in two ceramics layer - all should give even about 500mm vs HEAT. And we have 500mm thick "special armour" cavity which is unknown - it can be burlinghton style multi layers structure, or many internal NERA pannels. In simplest cenario (two-tree NERA layers) this cavit shoud offer about 300-400mm vs HEAT (based on "Disturbance of Shaped Charge Jets by Bulging Armour" pdf and polsih NERA pannels) so whole main armour protection should give more then 800-900mm vs HEAT(!)
When we add NERA panels this armour shoud stop even double SC warhed whit 1100-1300mm RHA perforation.
BTW: when we look at this value 800-900mm vs HEAT for turret without NERA pannels - its fairly consistent whit Metis and MEtis-M perforation level. After add NERA pannels its level between Kornet and Chrizantiema. Accidentally?
