We are rolling out the latest version of the Abrams main battle tank, the M1A2 SEP v.3.
Yet it lacks the latest active defenses that shoot down incoming anti-tank rounds. Which is a problem with top-attack rounds that can avoid the impressive passive protection of the Abrams' frontal armor by hitting the roof where armor is thin.
In counter-insurgencies this isn't a critical failing. But in a battle with a country that has lots of modern armor supported by air power, that's a potential critical failure point.
The Germans too are looking beyond their excellent Leopard II to a new design with heavy armor, active protection, and a bigger main gun.
Remember when the Army thought it could build a 19-ton Future Combat Systems vehicle with magical qualities that would allow them to deploy by air a replacement for the tank that would be as lethal and survivable as the Abrams? Yeah, heavy main battle tanks were "dinosaurs" on the road to extinction as the high tech furry mammals like the FCS evolved beyond tanks.
Yeah, good times (see my Military Review article "Equipping the Objective Force").
Although I once thought the debate had been settled from recent combat experience, I no longer assume that the lesson of heavy armor will be retained for long as the siren song of lightness tempts us to build vehicles more easily deployed around the world from the continental United States.
The main problem I thought we'd have with replacing passive (and heavy) armor with active armor on a light chassis is that an enemy could overwhelm an active defense system protecting a lightly armored vehicle with volley fire that overwhelms the active defense system:
We have decided to think outside the box and simply make thicker armor irrelevant to those bigger cannons and more lethal shaped-charge warheads on missiles and rockets. The enemy can improve their warheads and increase cannon size all they want and our active system will make it unnecessary to increase our passive armor protection. And to meet strategic mobility needs, we can get rid of all but the most basic armor protection to guard against small arms and shell fragments.
Nice theory. I don't buy it. No more than I buy that electric armor can't be beaten with simple kinetic penetrators. No, with all these expensive defensive systems, I suspect the enemy can keep it simple and make our high-tech devices look stupid.
So what if the enemy just volley fires cannon shells, missiles, or rockets at single vehicles? The old Soviet army trained their units to volley fire rather than engage individually. Can APS handle multiple, nearly simultaneous rounds coming in?
Heck, what if the enemy sprays our lightly-armored, APS-equipped vehicles with 25mm or 30mm armor piercing rounds? Rounds big enough to penetrate thin armor and numerous enough to swamp the capabilities of an APS? Even infantry could carry around these with ease. Heck, large tank rounds might dispense sub-munitions like a high velocity shot gun, giving a single tank round effective volley capacity.
In my view, a light FCS with active defenses would be slaughtered by heavy armor that also had active defenses (the term of art now is "active protection systems," or APS). Let me quote myself from that MR article:
A dangerous assumption is to think victory is certain and the only challenge is getting to the theater fast enough. If MBTs maintain their dominance with suitable modifications, enemies will have a tremendous advantage over the revolutionary FCS. The Army will get many FCS to the theater, but they may well die in large numbers against evolved dinosaurs.
As we look to bigger cannons, perhaps even 140mm (the Abrams now has a 120mm cannon), could we build APDS rounds (although technically the fin-stabilized version) that carry several dense kinetic penetrators capable of defeating heavy passive armor and designed to deploy sequentially from the sabot and strike the target one after the other?
The Russians built the RPG-30 with a decoy warhead that precedes the actual warhead to defeat a single-shot active defense system, as I note in an update to my post quoted above.
Would a round with multiple actual penetrators be stopped by an active defense system when the active defense system would have to fire three defensive rounds within milliseconds to knock down all three threats?
Remember, with the penetrators coming in one after the other, they would be separated in space too much for a single round to take them all down.
And even if active defenses get good enough to shoot down a number of incoming rounds in short order, would networking our tanks and other anti-tank weapons allow us to volley fire from several shooters to overwhelm a single target?
This race between shooter and active defender will mean that passive armor will always be needed to provide the last line of defense for our main battle tanks. Dinosaurs still roam the battlefield devouring their foes.
Well, I suppose that could all change if we move to robotic unmanned main battle vehicles that truly might represent the furry mammals that replace the dinosaurs. Without the need to protect crews, it may make more sense to build lighter vehicles to overwhelm with numbers rather than spend so much to make main battle vehicles survivable as well as lethal.