It is no surprise. We have known since WW2 that a heavy tank design was of limited use. I do not know what the magic number is but about 70 tons and above are the problem. Logistics of movement are a problem. Bridges, train tunnels, muddy regions etc⌠I think the Russian âT72â design is a great compromise with weight, firepower. size and armor. The auto loader and carousel storage is a short coming. I have not seen a way of keeping the T 72 design and eliminating the autoloader design. If it was it would be done in countries that operate the T 72 designs. So a new turret design would be required. At that point, just get a Leopard to keep the weight down and live with less armor. I believe something like the trophy system will be required on future tanks so it could help with using less armor.
I always thought that the turret would be replaced with a new version with various high tech items in it.
Is it going to be a completely new platform or a platform developed on the existing M1 hull ?
Is it going to be a completely new platform or a platform developed on the existing M1 hull ?
Unknown, but since M1A2 SEPs are taking from old stock Abrams hulls, it makes sense to incorporate lessons from the AbramsX such as placing the crew into the hull and adding the new engine.
The big âwhat factorâ is if the US Army wants the M1E3 to have a crew or three or four and an autoloader. So few details exist on the AbramsX that is disclosed. One has to be at AUSA to ask those questions direct. No ammo count was even given so Iâve no idea how many main gun and bullet rounds that AbramsX unmanned turret has.
I think we are talking about a vehicle with the same hull, new engine, new turret with active protection system and less than 65 tons combat weight. I dont think hybrid diesel electric propulsion will be used, since all the combat systems require a high electrical power installation.
The gun will probably remain the same and I dont think an autoloader will be an option. I find the whole project really interesting especially if we talk about an upgrade and not a new platform. I will be looking forward to any updates.
A couple other threads on this subject.
Highly informative, as is the other video he mentions which I had seen before. This one I had not.
Thanks, Nikos.
Weight will have to be a primary consideration, otherwise the M1A2 SE, P4 would be a go.
If they plan on 60 tons for the basic tank, you could be approaching 70 tons with a bunch of mods installed, ammo and fuel. They may be shooting for a base of less than 60 tons.
just a thought:
From my days of working in Plant 14, I remember the shipping weight of the gear box was 5700+lb. without the shipping container. The gas turbine was much lighter in weight, but you also had all the air and exhaust ducting to add in there. The Abrams X uses a much different power pack, and should fall in at about two thirds the weight plus batteries. A similar diesel engine alone will weigh more than the X1100 gear box alone (thinking of the Continental flat twelve). The new Cummins engine will come at about 50% of the other. So in the end the Abrams X probably saves three to four thousand pounds alone in the power pack. The newer track will probably weigh a thousand pounds less. I can easily see eight to ten thousand pounds lost without too much work, and no loss of armor protection
gary
Is the Active Protection system considered a standard or a feature on demand depending the area of deployment? Because depending on the answer the turret shape/weight changes a lot.
Well I donât think any of the tanks using or able to use the Trophy APS have incorporated it into the turret design yet. Placement for the system remains on the outside of the tanks slated to use it. Perhaps it is to remain in that fashion- it might even be a necessity for Trophy to be mounted in such a way. The Abrams X kind of looks like it has space for Trophy on the outside front of the turret sides and the Panther KF51 sure seems to have a big enough turret to incorporate it. The Challenger 3 is supposed to have it too but there has no been no info about how it is to be mounted. If it is to be a âmission specificâ sort of thing then external mounting would be the route for that because, as you said, removing or adding it would change the shape and weight.
I think the M1E3 will have something to deal with aerial dronesâŚcountering unmanned aerial systems (C-UAS)âŚand loitering munitions in addition to enemy RPGs and ATGMs.
On the AbramsX, the answer was a remote turret with a rooftop 30mm autocannon that can fire airbursting ammunition and two Independent Thermal Viewers and fire control turrets. But that negates the 12.7mm and 7.62mm rooftop machine guns. With APS, the radars should be able to detect incoming threats, but how far is unknown. With newer radars slaved to APS and the 30mm rooftop autocannon, it might be able to deal with C-UAS.
This might be the first evolution of a MBT with some form of EFFECTIVE air defense that isnât just rooftop machine guns blazing away for a lucky hit, meaning that the autocannon might be guided and aimed properly to effect hits.
Would the 30mm autocannon be overkill? Perhaps, but one wants that airbursting programmable fuse ammunition that is lacking in lower calibers. A SHORAD CIWS auto-laser on the roof might work.
Iâm not saying that the M1E3 will have a rooftop 30mm autocannon, just that I think the roof turret armor might be thicker and incorporate sensors, jammers, and perhaps weapons to deal with UAS and loitering munitions for top-attack. Recall, Russia has captured US Javelin ATGMs as seen on video news.
The trick now with MBTs would be similar to a modern Navy warshipâŚâdonât get hitâ and âprotect the MBT with a defensive bubble of weapons and jammers instead of just armor.â From thick WW2 battleship armor that can take hits, newer MBTs will have the behave like modern warships and reach out to defend itself instead of solely depending on its own armor for defense. Thatâs hovertanks for you. 
I think the main issue of the current Abrams turret setup is the large area on the rear of the turret that has to remain clear for the blast panels on the roof. So if the upgrade intends to keep the turret might lead to an increase to the turret height, especially the rear half in order to make space for the APS and other electronics and maybe another row of ammunition in the turret.
We might also be looking to the removal of the side stowage bins and maybe the move of the smoke launchers (if retained) to the front panels of the turret, similar to what a Challenger 2 has.
Another change could be to lengthen the turret at the rear and include inside the turret the additions made to the SEP variants and installed at the bustle rack. This will also provide more space for other systems at the rear of the turret roof.
Regarding weight reduction, a new engine with increased fuel efficiency will lead to a reduction of the total fuel carried in the tank provided the requirement for the total distance the tank can travel remains the same as now. Weight can be saved by altering the electrical power production and distribution systems.
Carbon fiber. 
It also depends on if the M1A3 will have three or four crewmembers and if the crew will be in the hull or not. If the loader is gone, then the turret can be remote unmanned just like the AbramsX with an autoloader. If the loader is included, then obviously the turret will be manned.
The Russian T-14 Armata can be a step towards a radical M1A3. Or place the AbramsX into production with modifications. The US Army should then test the AbramsXâs effectiveness on loan.
Nonetheless, M1A2SEPs are remanufactured from existing hulls so it is essentially building a new Abrams from scratch for the M1E3 and M1A3.
I wonder how long the existing hulls can be rebuilt before theyâre just too worn out? Or does that even matter because they replace every possible thing on them?
They strip the hull completely, down to bare metal and start over on them. They are expected to last a really long time, almost indefinitely.
This article lays out the process well.
Rebuilding the M1 Tank (businessinsider.com)
There was also a great show on the National Geographic Channel that walked through the process.
âMegafactoriesâ M-1 Tank (TV Episode 2006) - IMDb
Perhaps the only thing that wears out on the hull are the torsion bars, the suspension arms and the wheels. The rest can be pretty much overhauled and reused as mentioned above.