Or, more specifically, why they decided to do the M1A3 rather than than M1A2SEP4. And the main reason is weight.
“This list of proposed capabilities for the new design that include:
An autoloader
New main gun new turret
Hypersonic gun launched missiles that maneuver in midair
The ability to pair with robots
Masking capabilities to reduce thermal and electromagnetic signatures
AI systems that detect incoming fire and prioritize return fire
Hybrid electric drivetrain
Reduction of crew from 4 to 3.
Reduction of weight from 75 tons down to sub 60 tons.
But the coolest thing is it’ll likely get a brand new sleek hull for the first time in 30 years.”
“US Army leadership [is] reversing course on decades of tank design philosophy to do a last minute complete overhaul from the ground up based on new lessons learned from the war in Ukraine.”
The gun-launched anti-tank guided missile is something the army has worked off and on for a long time. The Soviet’s had one, but mainly because their main guns were inaccurate at longer ranges. U.S. had a prototype ATGM that hit a T-72 at 8,600 meters. “But the Army never invested in it to go full rate production. Part of the reason for this might be because it’s also true that tank-launched ATGMs have a smaller warhead and they don’t perform as well against modern composite armor compared to the 1970s.”
So why does the army want it now? Line of sight studies in Latvia and Lithuania (i.e, the border with Russia) shows a whole lot of areas where it would be useful.
Tank optics are also a lot better now.
The new XM 360 cannon uses the same 120mm diameter, but save a full ton of weight by using composites, and delivers the same 17 megajoules of energy to the target as a conventional 140mm cannon, thanks to more efficient plasma ignition.
The Russo-Ukrainian War reveals a much more deadly threat environment for tanks. Drones are a huge threat.
“They’re going to link the new cannon to a remote-controlled, optionally manned turret by switching to an autoloader and making the turret interior smaller. That’s a lot less volume that has to be protected by heavy armor, which equates to a lot less tons of armor.” When we last checked with western tankers looking at the T-14s autoloader some six years ago, they were skeptical of both smaller crews (“all we do is maintain tanks, and they still break down”) and autoloaders (Abrams tank crews currently put shots on target faster than Russian crews with autoloaders). But since then, the Russo-Ukraine War happened and technology galloped furiously, and presumably higher crew survivability will make the tradeoff worthwhile.
M1A3 almost certainly wouldn’t have the cassette design that gives the T-72 its turret toss reputation. “Newly designed autoloading tanks can have all of their ammo secured behind a bulkhead blast shield and can work with blowout panels to prevent detonation from cooking the crew.”
“We’ve also seen from combat in Ukraine that the Abrams engine deck with it air intakes and radiators is a popular target point for drone swarms, so the army is looking at unique ways to keep the engine better protected from above without sacrificing cooling performance.”
“The new M1A3 Abrams tank would also upgrade from that puny 50 caliber machine gun to possibly the 30mm chain gun remote weapon station. The big advantage there is that it could fire specially made 30mikemikes that provide air burst capability for shooting down drones.” That sounds both awesome and the makings of an extremely complex turret with multiple automatic-feed weapon systems.
“We have to remember that systems enhancement packages was always supposed to be a stopgap temporary band-aid solution for the Abrams, because the service thought that they would do with that until a full replacement vehicle was chosen that’s how we ended up with like a dozen different variants of Abrams tanks with various levels of advanced features in the early 2000s.”
“The main difference between the M1A1 and A2 is its electronics. However, with this new M1A3, it’s now likely to have a whole brand new hull and turret. There’s conflicting reports on that, but I can’t see any other way that we get the kind of weight reductions that they’re looking for without a whole new hull.”
“The first version of the Abrams tank weighed 54 tons. The SEPV4 that was cancelled was on track to weigh over 75 tons. Add in a mine plow and it was going to break the scales at 83 tons.”
In May this year, an expert analysis board came to some sobering conclusions. “The M1A2SEP3 and 4 upgrades will improve effectiveness, but not restore dominance. Near transparency in all domains will significantly increase the lethality our forces will experience. We will continue to have to fight outnumbered, exacerbated by a low MBT operational readiness rate and aging fleet.”
“Lessons learned in Ukraine is that tanks are sometimes dead meat if they’re too heavy. They get stuck in the mud, they’re too slow not nimble enough to fire and then escape from drones that are searching for them.”
That same Latvian-Lithuanian study showed lots of no-go zones for Abrams due to their weight in muddy conditions. “From a tactical perspective a defending Force could easily mine trafficable routes, destroy bridges to complicate Abram’s combat operations during the wet season and funnel them into choke points.”
“The study recommends new band tracks to lower the ground pressure to help fix that problem along with the lighter weight.”
SEPV3’s heavier weight lowered operational range from 300 miles down to 264.
He references the role of tank in the army’s current FM3-0 Operations Guide, which you can read at the link.
Transcom says that SEPV3 is too heavy to transport for a lot of roles.
Meantime between failure for current tanks is 200 miles, which does seem worrisome.
“It will likely have the hybrid electric drivetrain that reduces fuel consumption by 50%.” He calls it the Prius of tanks, but it’s not ugly enough for that.
More stealth.
More active protection.
“The future of armored warfare, the way the army envisions it, is that they’ll be preparing for a major change to tank tactics unlike anything we’ve seen since the introduction of the Abrams in 1980 …they all seem to believe that the future will be a combination of manned and unmanned platforms that are integrated with aerial UAVs. The M1A3 is the first step in that direction.”
A major Abrams redesign was probably slightly overdue anyway, but the torrents of real-world information coming out of the Russo-Ukrainian War forced their hand to make more radical changes.