Russia’s brutal invasion of Ukraine has resulted in the destruction of thousands of main battle tanks, many at the hands of cheap drones loaded with anti-tank grenades. But it has also driven demand for new-built tanks to a level unmatched since the end of the Cold War.
To mitigate the drone menace, French, German and U.S. engineers have now all proposed next-generation tanks incorporating a seemingly outdated and discarded concept: multiple cannons.
In June, KNDS—a German-French conglomerate of defense manufacturers Germany’s KMW and France’s Nexter—unveiled three full-scale concept main battle tanks, all featuring a secondary 30-millimeter autocannon to help kill drones, active protection systems, and a new main gun called Ascalon able to rescale between 120- and 140-millimeter diameter shells.
Those on display notably include a new, fully-functional prototype of Germany’s popular Leopard 2 tank called the A-RC 3.0 (standing for ‘remote control, only three crew’), and a mockup of a proposed ‘Evolution’ model of the French Army’s Leclerc tank.
For an encore, it also unveiled a beastly ADT140 demonstrator tank, armed with the biggest 140-millimeter 48 calibers variant of Ascalon with a 22-round autoloader, an ARX-30 autocannon turret (150 rounds), and both a coaxial 20-millimeter autocannon (with 300 round of 20x102mm ammunition) and a coaxial 7.62-millimeter machine gun.
These proposed multi-cannon tanks echo the AbramsX tank concept, which was revealed in October of 2022 by General Dynamics Land Systems (GDLS) and sported a belt-fed Kongsberg XM914 Bushmaster Remote Weapon System. That’s based on the M230 chain gun used on the Apache helicopter, ordinarily capable of firing up to 5 round per second.
While tanks with multiple cannons aren’t unprecedented, this design concept mostly vanished post-World War II. Too often, the additional guns had limited fields of fire, the crews of the tanks were overworked aiming, firing, and loading the extra cannons (leading to low firing rates), and the increased volume and weight left the vehicles too heavy, prone to bog-downs, and (in some cases) lacking adequate armor density.
But come 2024, proposed Leopard 2 A-RC 3.0, ADT-140 and AbramsX concept tanks all feature a crewless remote-control turret with an autoloading main gun—a concept first implemented in the T-14 Armata main battle tank that Russia has so far been unable to produce and use sustainably in combat. T-14 concept art also envisioned a secondary autocannon which didn’t make it into the production models.
Unmanned turrets that don’t ingress into the tank’s hull are made feasible by combining autoloading main guns with advanced optical sensors to provide all-around vision, possibly mated with helmet technologies that allow crew to see ‘through’ the tank’s hull. Those sensors allow the commander (using an independent thermal sight, or CITV) and gunner to do their jobs from inside the hull, despite lacking vision or access to the turret. The crew enters through flush hatches just under the ‘chin’ of the turret on either side of the front hull.
Replacing the human loader common in current Western main battle tanks (save the Leclerc) with an autoloader would also downsize the crew to 3, allowing for a reduction in volume and weight. In the case of the Leopard 2, that allegedly reduces turret weight by at least 6.6 tons—improving mobility while freeing spare weight for denser armor protection.
The resulting flatter turret reduces the crew’s exposure to antitank fire by 30%, making it harder to spot. And, most importantly, the sealed-off crew in the hull is likely to survive penetrating hits to the shell-laden turret.
The weight savings would allow new autocannons to replace the traditional top-turret .50-caliber heavy machine gun operated by the tank commander for air defense, and sometimes to supplement the tank’s coaxial machine gun next to the main gun.
The upgrade from .50-caliber bullets to 30-millimeter shells should increase the effective range and armor penetration, but at a major cost to ammunition depth (30 millimeter shells are a lot bigger than .50 caliber rounds).
But the foremost reasoning behind up-gunning to 30-millimeter cannons is the ability to swiftly swat the small drones that, by 2024, are reportedly accounting for more armored vehicles losses in Ukraine than traditional anti-tank weapons are.
Though a .50 round packs enough punch to potentially disable a small drone with a direct hit, a new air-bursting 30x113-millimeter smart shell by Northrop Grumman—the XM1223 Multi-Mode Proximity Airburst (MMPA) round—doesn’t require a direct hit, and is able to shred drones several meters away with a high-explosive fragmentation warhead.
Armored warfare expert Nicholas Drummond, an advisor to KNDS, told Popular Mechanics that the new round had “transformed” the M230LF gun. “It has proved itself to be extremely good at knocking down UAS [aerial drones] of all types at ranges up to 1,500 meters [nearly one mile]. It does this at relatively low cost.” These qualities, he pointed out, already saw XM914 integrated into the RIwP very-short-range air defense turret used on Army Stryker APCs and Marine JLTV trucks.
Drummond argues that such air-defense autocannons, combined with hard-kill active protection systems, are now “obligatory” for tanks, though he concedes they increase costs. “In the wider scheme of things, [tanks] are becoming niche weapons used for combined arms assault roles rather than general combat,” he wrote to PopMech. “Even so the C-UAS capability provided by lightweight 30 mm cannons has restored the primacy of the main battle tank.”
Like bigger XM1147 rounds useable on the latest Abrams tanks, the XM1223 shells can also be programmed to airburst above targets behind cover or in trenches, detonate on impact when blasting vehicles, or set to delay bursting until after the penetration of a building wall.
Another important factor is that new hunter-killer fire control technology could finally enable a secondary autocannon to engage different target tagged by the tank commander simultaneously to the main gun. That could also include fast-reacting automated defensive fire aimed at shooting down incoming missiles or kamikaze drones.
A German mechanized infantry officer also told PopMech that with “the increase of the main gun to 130mm or 140mm I think it becomes necessary to engage smaller targets [with a different gun] to save ammunition.” For example, the Leclerc’s autoloader can fit twenty-two 120-millimeter shells, but only eighteen 140-millimeter rounds. He added that with suitable sensors and software—secondary autocannons can also take on counter-drone duties.
The officer also opined that secondary 30-millimeter cannons, 3-person crews with autoloading guns, and active protection systems (most likely, Trophy) would undoubtedly become standard in future Western tank designs. The officer was less certain unmanned turrets would be adopted in the near-term.
How do Abrams X and Leopard 2 A-RC3.0 differ?
It’s not surprising AbramsX and Leopard 2 A-RC3 concepts share features in common—the designs were developed concurrently in the 1970s, and achieved comparable performance despite differing in propulsion and materials used for armor and munitions.
But the new proposals do differ in armament. KNDS is offering Nexter’s scalable autoloading Ascalon cannon, debuting in a 120-millimeter/58 caliber configuration. But these can swap in a 130- or even 140-millimeter/48 caliber gun in just an hour’s time, with the latter weighing 441-pounds more. There is interest in bigger shells to help defeat the T-14’s front hull plate, allegedly equivalent to 1 meter rolled-homogenous steel armor.
The 140-millimeter ammo, previously test-fired by a unique Leclerc ‘Terminator’ testbed, uses telescoping one-piece shells larger in diameter than any currently in operational service on tanks. Allegedly, Ascalon’s autoloader has a surge firing rate of three rounds in 10 seconds—faster than a human loader can achieve.
The neo-Leopard 2 also incorporates a turret-top missile launcher beside the autocannon, both for direct fire at ranges up to 5+ miles, or to attack targets outside the tank’s line of sight (say, concealed behind a hill or buildings). The missiles can be fired while moving, with long-range targeting facilitated by new third-generation thermal/infrared sights that will also improve performance of the tank’s Trophy active protection system.
The AbramsX demonstrator, however, sticks to 120-millimeter rounds fired from a new, longer-barrel 57-caliber XM360 cannon by GDLS. It generates 14% more muzzle velocity (increasing range, accuracy, and armor penetration) despite weighing less than Abrams’s current 44-calibers M256 gun, thanks to use of composite materials and titanium.
AbramsX would also use hybrid diesel-electric engines, resulting in a projected 50% fuel efficiency improvement over the AbramsX’s, responsive but notoriously thirsty, gas-turbine engine. Electric propulsion would also enable a time-limited ‘silent’ movement mode.
KNDS hasn’t much discussed propulsion, but Drummond claims that the Leopard 2 ARC-3.0 will also get a new hybrid powerpack by Renk and in-arm hydropneumatics suspension.
The company’s press releases do explicitly claim a reduction to the tank’s electromagnetic signature and thicker integral top armor on the Leopard 2 A-RC 3.0 and ADT-140, to protect against ‘threats from above’ (i.e. drones).
The French (and German) Connection: Leclerc Evolution, ADT-140 and MGCS
While the proposed Leclerc Evolution also uses the Ascalon gun, it differs from KND’s other concepts by retaining a manned turret and adding a fourth crew member—a ‘deputy commander’ in the hull, operating the secondary ARX-30 autocannon, sensors, and a new retractable drone launcher that is loaded with three loitering munitions and used for extended range reconnaissance and kamikaze attacks. The model also sports non-explosive reactive (NERA) tiles, which are reusable (unlike most reactive armor). This configuration increases weight from 63 to 68 tons when fully fitted, with beefed-up Azur armor.
The gryostabilized ARX-30 turret—also specifically billed as a counter-drone weapon with a max elevation of 55 degrees—uses the electrically-operated GIAT 30M781 revolver cannon from the Tiger-HAD attack helicopters, each of which has a firing rate ranging from 3 to 12 rounds per second. In addition to its optical/infared sights, there are variants also equipped with either a Nerod multi-frequency counter-drone jammer or a Matia Terahertz radar, designed to detect and classify drones and program air-bursting shells to destroy them.
France operates a total of 222 Leclercs in four regiments. Currently, the French Army has received the first 28 of 130 modernized Leclerc XLRs (with new fire control, navigation, and SCORPION battle management systems), as well as programmable M3M anti-personnel shells, counter-mine systems, and additional composite and slat armor.
Furthermore, KNDS also just unveiled a new Shard-120 fin-stabilized discarding sabot shell with a lengthened tungsten-carbide alloy penetrator for Leclercs. This boasts a 15% increase to penetration, while reducing barrel wear by 25%.
Perhaps the non-XLR upgrade Leclercs could eventually receive an Evolution refit instead, and some argue that France should reactivate roughly 180 retired Leclercs in storage. Alternately, Leclerc Evolution might be aimed for sale to the UAE, which operates roughly 350 tropicalized Leclercs that performed satisfactorily against Houthi rebels in Yemen in the mid-2010s.
KNDS’s proposed slimmer Leopard 2s and buffer Leclercs are marketed as intermediate stopgaps until France and Germany complete their ponderous co-development of a next-generation Main Ground Combat System (MGCS) tank.
The ADT-140 demonstrator represents a seemingly maximalist pitch for what MGCS itself could look like.
Officially a new iteration of the proposed European Main Battle Tank (E-MBT), the many-eyed ADT-140 (unveiled in 2018) has no less than six radars to detect incoming drones and projectiles, 22 tile-like countermeasure launchers distributed across hull turret edges for ‘full-hemispheric’ defense, four laser/missile warning sensors, an acoustic gunshot detector, and a 360-degree camera suite.
Like KNDS’s other proposed vehicles, the ADT-140 has a 1,500-horsepower engine that allows for a max speed of 40 miles per hour and range of 280 miles. Rather than the Israeli-built Trophy APS, the ADT-140 demonstrator is fitted with Nexter’s Prometeus APS, which is distributed across the vehicle and has a .1 second reaction time and 360 degree coverage.
MGCS seems likely to arrive 5 years late from the original 2035-2040 delivery goal, widening the opening for possible intermediate solutions. Currently, the plan is for France to contribute sensors and secondary armament and for Germany to develop the tank’s hull, armor, and counter-drone systems. But the remainder, including the turret and main gun, is up for grabs.
KNDS’s concepts may be aimed at fending off competition from Rheinmetall’s proposed KF51 Panther tank, also based on the Leopard 2 hull. At the same event, Rheinmetall unveiled a Concept Unmanned Turret System (CUTS) for Panther armed with its Rh-130 130-millimeter gun, which allegedly generates 50% greater penetration than current Rh-120. CUTS incorporates a 25-round autoloader, a coaxial .50 cal machine gun, 360-degree sensors, and the Muss 2.0 soft-kill and Iron Fist hard-kill active protection systems, but no secondary autocannon.
It's not guaranteed the industry’s proposals for tanks with secondary autocannons, bigger main guns, remote control turrets, and integral drone launchers will be embraced by armies of France, Germany, and the U.S.
The services are likely wary of anything increasing the already daunting cost and complexity of main battle tanks, but are also aware that battlefield developments in Ukraine—particularly related to mine and drone warfare—may require tanks to evolve more rapidly in order to survive future battles. Perhaps new sensors and autonomous AI technologies are just what’s needed to make the old concept of the multi-cannon tank actually work.
Sébastien Roblin has written on the technical, historical, and political aspects of international security and conflict for publications including 19FortyFive, The National Interest, MSNBC, Forbes.com, Inside Unmanned Systems and War is Boring. He holds a Master’s degree from Georgetown University and served with the Peace Corps in China. You can follow his articles on Twitter.
