Again, shaped charges are for punching through things.
This is a shaped charge. You do not need or want them for this kind of application.
I forgot a few other things that should be noted in prior post.
A important consideration that needs to be considered in regards to the effectiveness of ERA in regards to solid impactors is the projectile velocity. A modern APFSDS such as the KEW-A1 travels 1,700 m/s whereas anti-armor shots from SARP infantry kinetic-kill weapons travel 6-9,000 m/s and faster. This much higher projectile velocity would make the ERA less effective against all of the kinetic-kill rounds.
Another item that must be considered is the geometry of the ERA tile and its placement on the armor. The effectiveness of any form of ERA is dependent on its thickness, since a thicker tile will have comparably greater ability to deflect a shaped-charge jet. I can't find hard numbers on IRL ERA tile thickness, but from the
pictures it seems to be a few inches thick, so the submission is on the thin side.
How the module interacts with the armor also needs to be considered. Each of these modules is only going to protect against a fairly narrow arc of the armor, which is going to necessitate a good number of them to be incororporated. Considering the weight of these modules (which is not at all excessive, they are large metal and explosive bricks, they should be on the heavy side) I can see that causing not inconsiderable weight. Adding a significant percentage of the armors weight would likely through off its balance, which would make it more difficult to maneuver (again, these aren't problems for IRL ERA. Tanks don''t dodge). More importantly than any maneuvering hindrances the panels would cause, the extra weight would affect it in close combat.
Again, the major negative of it is the fact you are detonating a concequential amount of powerful explosive right on the armor. Yamataian PAs are both thin and light. The latter (along with the fact that inertialess drives are used, so the armor has none to counter the blast force) means that the explosion is quite likely to knock around the armor (and the pilot). The former means that the armor can't have much in the way of padding to mitigate the blast. This is a restriction applied on it by the laws of physics and not something super tech padding is going to change. Padding works by increasing the distance (and therefore time) over which a object (in this case the pilot) accelerates or decelerates. With a armor that is, at most, a inch or two thick that thin layer has to contain both the PAs armor panels, its systems, AND the padding so its not going to be able to have much of it.
In Summary
*I can see this system having a -2 ADR against the limited weapon subset of shaped-charge and small-bore long-rod penetrators, though it should be kept in mind that the tiles do seem to be on the thin end. It has also just occurred to me that against long-rod penetrators the fragments are still going to have their full inertia and kinetic energy so even though the penetrative ability is reduced they are still going to have enough energy and inertia to cause (potentially lethal) damage to the pilot.
*Against more generalized kinetic-kill rounds, I could see
maybe a -1 ADR against the small-bore hypervelocity rounds (such as the LASR) since the bullets, despite their immense velocity, have comparably small inertia. However, most of these small-bore KK weapons fire in bursts, which would substantially reduce the effectiveness of the ERA so I don't think it would have any meaningful effect against bursts from such weapons.
*Against large-bore hypervelocity rounds and supra-velocity (such as relativistic railguns) rounds of any caliber I do not think it would have any meaningful effect. The first are simply to too durable and have to much inertia to be effected by the ERA. The second are just going to fast for the ERA to effect.
*Against other weapons in the setting (Scalar, lasers, explosives, etc) I do not think the ERA would have any meaningful effect.
With all of these it must be kept in mind that the wearer is /also/ going to be taking damage from the blast since the armor just can't provide much padding. They are also going to be knocked about quite a bit. I am not sure how this would be codified, but it would be a problem since the damage is going to be substantial.
Although any level of non-lethal damage is going to be better than a shaped-charge punching through to incinerate the pilot, considering the minimal-to-negligible (and one-shot nature) defense against most weapons in the setting I don't think this submission would be terribly useful to the SAoY.
Edit:
I don't think the size of these devices (relative to their explosive power) would make such a shock absorbing system useful Yoroko. It just wouldn't have the play to cushion enough of the explosive blast to matter. It would also exacerbate the already existing issues with the modules mass and bulk.
Also, bear in mind that the objective of ERA is to
deflect and
disrupt a hit, not destroy the impacting round. It would take a lot of explosive to have enough energy to physically destroy a solid metal impactor and that explosive would assuredly be lethal to the pilot of the slim armors that are in use by Yamatai.
