Army Axes M1A2 SEPv4 Abrams, Bets Big On Next-Gen “M1E3”

The service has elected to ditch development of the M1A2 SEPv4 in favor of a lighter, smarter, more survivable M1 Abrams main battle tank.

byOliver Parken|
AbramsX Next Generation Main Battle Tank
General Dynamics video Screencap


The U.S. Army is pushing ahead with plans for a next-generation M1 Abrams main battle tank, which the service is calling "M1E3," having now decided to axe development of the M1A2 System Enhanced Package Version 4 (SEPv4).

According to the service, the move away from SEPv4 relates to the need for tanks with increased mobility and survivability, in light of the war in Ukraine, with lighter-weight, more adaptable systems required on the battlefields of 2040 and beyond. It’s unclear at present how the Mobile Protected Firepower (MPF) light tank initiative factors into this decision, if at all. 

The Army announced its intention to pursue a more ambitious modernization strategy for the M1 earlier this week. “The new approach balances costs with the Army’s needs and invests in the nation’s defense industrial base,” it said. Initial operational capability (IOC) of the M1E3 is anticipated by the early 2030s. Despite the designation having been used by the service to describe various future ‘modernized’ Abrams concepts since at least 2010, it notes that “the M1E3 Abrams nomenclature is a return to the Army’s standard use of its type classification and nomenclature system for our combat vehicle fleet.” The ‘E’ especially is used to illustrate the significant engineering changes involved compared to the previous system, and the type’s prototype status, per the service.

“The development of the M1E3 Abrams will include the best features of the M1A2 SEPv4 and will comply with the latest modular open systems architecture standards, allowing quicker technology upgrades and requiring fewer resources,” the Army says.

M1A2 SEPv4's prototype. U.S. Army

Which features this pertains to specifically remains unclear. We’ve reached out to the Army for more details. However, we do know that the SEPv4 was set to feature a number of critical add-ons to the SEPv3. This included an upgraded Gunner's Primary Sight (GPS) and Commander's Primary Sight (CPS); lethality improvements, which included the addition of a digital data link capable of communicating with the Army's reprogrammable XM1147 Advanced Multi-Purpose (AMP) round for the tank's 120mm main gun; additional new sensor systems; upgraded communications and data-sharing abilities; and onboard diagnostics systems, among other features. The Army awarded a contract to General Dynamics Land Systems (GDLS) for the development of SEPv4 in 2017, with previous hopes that the vehicle would be fielded to operational units in Fiscal Year 2025.

M1A2 SEPv3 prototype. General Dynamics Land Systems

Bringing the best of SEPv4 to the next-generation M1 “will enable the Army and its commercial partners to design a more survivable, lighter tank that will be more effective on the battlefield at initial fielding, and more easy to upgrade in the future,” as service suggests. For the time being, the Army will continue to produce the M1A2 SEPv3 at a reduced rate until production transitions to the M1E3 Abrams.

Concerns with the weight of the SEPv4 version, and how its add-ons would impact mobility and survivability, were a core part of the reasoning for scrapping its development. “We appreciate that future battlefields pose new challenges to the tank as we study recent and ongoing conflicts,” said Brig. Gen. Geoffrey Norman, director of the Next-Generation Combat Vehicle Cross Functional Team. “We must optimize the Abrams’ mobility and survivability to allow the tank to continue to close with and destroy the enemy as the apex predator on future battlefields.”

“The Abrams tank can no longer grow its capabilities without adding weight, and we need to reduce its logistical footprint,” said Maj. Gen. Glenn Dean, program executive officer for Ground Combat Systems. “The war in Ukraine has highlighted a critical need for integrated protections for Soldiers, built from within instead of adding on.”

It should be noted that worries over the weight of the most modern of M1s, particularly from add-ons, have been evident for some time within the Army. A key example separate from the SEPv4 development initiative, for example, relates to efforts to integrate Trophy Active Protection Systems (APS) onto existing M1A2 tanks. A “hard-kill” system which fires shot-gun like blasts, Israel’s Trophy increases survivability against anti-tank missiles, RPGs and other threats, but adds a lot of bulk, sacrificing the M1's mobility. 

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As Scott Taylor, GDLS’s director for U.S. business development revealed to Breaking Defense earlier this year: “[The Army has] been concerned about the weight class of the Abrams SEPv3… that is pushing 76 to 78 tons combat loaded,” with the updated features of the SEPv4 raising those weight figures “slightly higher.”  

The sponsors bolted on to the side of the Abrams turret that house the Trophy's radars and other systems can be seen in this image. (US Army)

As we’ve noted previously, the weight of the more modern M1 variants, coupled with their physical proportions, bring problems beyond the battlefield. This is particularly true in terms of transportation and fielding. The weight of the SEPv3 variant imposes limits on how they can be transported. For the 31 older, refurbished M1A1 variants bound for Ukraine from the U.S., which tip the scale at a comparatively svelte 63 tons, there are already concerns that the vehicles may struggle to cross bridges that are not designed to support their weight. Although it was hoped that the first of those tanks would be ready to go into combat around mid-September, Kyiv has requested an extension in training its troops at U.S. bases in Germany until the full M1A1 contingent is ready, with the additional training expected to take several weeks. You can read more about what the M1 will bring to the fight in Ukraine in our previous feature here

For the Army, the starting point for the M1E3 may well be GDLS’s future main battle tank demonstrator, the AbramsX, which the company unveiled in October last year. Although AbramsX does not in any way constitute the final M1E3 design, it boasts many of the requirements the service is looking for in terms of mobility, performance, and ease of upgrade/repair. 

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AbramsX is lighter than the SEPv3 and the SEPv4, or even the the M1A1 for that matter, with the demonstrator weighing some 59 tons. Combined with a hybrid conventional-electric propulsion system, it loses none of the range of the M1A2 Abrams but operates with far greater fuel efficiency. “The AbramsX technology demonstrator features reduced weight for improved mobility and transportability, delivering the same tactical range as the M1A2 Abrams with 50% less fuel consumption,” according to GDLS. The intense thirst of the M1’s turbine engine has long been a major logistical hurdle to overcome and it has many other impacts on force structure and support needs. Alongside improved fuel efficiency, the hybrid conventional-electric propulsion system has other benefits, such as operating in a very quiet all-electric mode to avoid detection. 

AbramsX demonstrator. General Dynamics video screencap

The overall form factor of the AbramsX is also smaller given that the vehicle boasts a reduced crew size of three individuals, rather than a crew of four people, who will all be seated in the the tank's hull. This not only increases their survivability but allows other features to be packed inside its highly revised turret that features multiple sensors. Active protection systems are built into the AbramsX concept from the start and get rid of the need for heavy and ungainly bolt-ons. The demonstrator’s remote weapon station sports a large 30mm chain gun and it has an auto-loading gun. Above all else, the tank's open architecture digital backbone will allow it to be upgraded with far greater ease and under much tighter timelines.

In terms of battlefield connectivity, GDLS has stressed that “with… AI-enabled lethality, survivability, mobility, manned/unmanned teaming (MUM-T) and autonomous capabilities, AbramsX can be a key node in lethal battlefield networks.” This would make it a critical networking hub for uncrewed combat vehicles, such as 30mm cannon-armed Ripsaw M5 unmanned mini-tanks, which the service sees as important in performing a range of functions in future conflicts — including “loyal wingman” type roles.

Whatever the Army ultimately chooses for the M1E3, it’s clear that the service sees lighter and more survivable tanks as critical assets on the battlefield for the foreseeable future.

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