Key Points – The United Kingdom’s Challenger 3 is a significant modernization of its predecessor, featuring a new NATO-standard 120mm smoothbore gun, a completely redesigned turret with advanced sensors, and a new Active Protection System to counter modern threats like FPV drones.
-While these upgrades will make it a far more capable and interoperable main battle tank, a recent analysis by the Royal United Services Institute (RUSI) highlights a critical flaw.
Challenger 3 Tank. Image Credit: Creative Commons.
-With only 148 tanks planned for service by 2030, the British Army will lack the numbers required for a “credible” armored division, casting doubt on the platform’s strategic relevance in any large-scale, attritional conflict.
The Challenger 3 is Better than its Predecessors—but Will That Be Enough?
The British Army touts the new Challenger 3 main battle tank. Still, questions about low acquisition numbers and the increasing challenge from the FPV threat cast doubt on the tank’s future survivability.
The Challenger 3 is the United Kingdom’s upcoming main battle tank, a deep modernization of the older Challenger 2, and one that, on paper at least, will give the British Army a significantly more capable armored platform. The Challenger 3’s upgrades focus on enhancing interoperability with NATO forces and improving the tank’s battlefield effectiveness.
The most significant changes are the Challenger 3’s armor protection package, main gun, and ammunition.
Into the Fold of NATO Standardization
The most significant change to the Challenger platform is the introduction of a NATO-standard 120mm smoothbore main gun. Though long the mainstay of NATO member country’s main battle tanks, the German-designed gun did not find favor with the British. For many years, the British Challenger main battle tank was favored with a rifled main gun instead. This design consideration supports the use of high-explosive squash head (HESH) rounds, which are flexible munitions that excel at engaging both protected positions and heavily armored vehicles.
With a turn toward the 120mm smoothbore main gun, the British Army will take their venerable HESH rounds out of service. Without the stabilizing effect imparted by barrel rifling, these rounds lose their battlefield utility. The upshot, however, is that the British Army will finally train with and operate NATO-standard 120mm ammunition, a mature and flexible NATO caliber.
The Challenger 3’s turret necessitated a redesign to accommodate the 120mm smoothbore. As part of that change, the turret’s armor protection is increased, as are the tank’s fire control and situational awareness capabilities.
The Challenger 3’s hull, on the other hand, is similar to the older Challenger 2, though with the incorporation of survivability and mobility. But in light of the threat posed by FPV drones, one of the Challenger 3’s most significant upgrades is its active protection system.
Active Protection
The previous editions of the Challenger lineup utilized thick layers of steel, ceramics, and other materials to provide the tank crew with a robust armor protection package, similar to the composite sandwiches seen in the Dorchester and Chobham armors. And while the Challenger 3 will be better protected than its predecessors, perhaps its most significant upgrade will be an active protection system.
Using an acoustic sensor suite and radar detection, the Challenger 3’s active protection will fire kinetic — that is, non-explosive — projectiles at incoming objects. By disrupting their flight path or causing them to explode prematurely, the Challenger’s active protection provides a higher level of protection than previous anti-drone measures observed during the war in Ukraine.
If it will be enough, particularly against the ever larger, higher-flying, and more lethal explosive-laden drones seen in that war, remains to be seen.
A Numbers Game
The Royal United Services Institute, a British think tank and one of the oldest defense and security tank tanks in the world, released a recent study analyzing the state of the the British military and the future of the Challenger 3 main battle tank. RUSI’s conclusion paints a far less rosy picture than that of British lawmakers and points to a shortage of overall numbers — a shortage that could prove to be crippling.
“Similarly, when RUSI analysts last looked at the Army and the combat division the UK claims to have, it measured the number of main battle tanks and self-propelled artillery in the UK’s inventory and found the numbers wanting when set against a ‘credible’ armored division of anywhere from 170 to over 300 tanks and around 110 to 220 artillery pieces,” RUSI said.
“The numbers have not improved in the subsequent four years: under the Challenger 3 program, the UK will have a total of 148 main battle tanks (in 2030).”
The think tank adds that “the UK has essentially removed the AS90 artillery from service by donating 32 to Ukraine, replacing them with 14 Archer guns until the ‘Mobile Fires Platform’ is procured (sometime ‘this decade’).
The Challenger 3 may be the ‘most lethal tank’ ever fielded by the British Army. Still, it is going to be available in such limited numbers that it will have to perform heroically in the face of a notional foe in the form of Russian ground forces, such as a Combined Arms Army.”
MORE: Russia’s T-14 Armata Tank Is a Failure
MORE: Russia’s T-90 Tank Has a Disco Head Problem
Postscript
There is no doubt that the Challenger 3 will be a significantly better-armed and better-armored main battle tank for the British Army than the older Challenger 2. Improved interoperability with the NATO alliance and simplified alliance logistics are undoubtedly positive aspects of the program. However, the enormous number of tanks currently on the battlefield casts a shadow over the program, given its modest acquisition numbers.
Challenger 2 Tank. Image Credit: Creative Commons.
In an attritional fight, such as the one seen in Ukraine, maintaining the small British fleet would be a significant challenge. When paired with modern FPV threats, questions about the Challenger 3’s survivability and sustainment remain nebulous.
About the Author: Caleb Larson
Caleb Larson is an American multiformat journalist based in Berlin, Germany. His work covers the intersection of conflict and society, focusing on American foreign policy and European security. He has reported from Germany, Russia, and the United States. Most recently, he covered the war in Ukraine, reporting extensively on the war’s shifting battle lines from Donbas and writing on the war’s civilian and humanitarian toll. Previously, he worked as a Defense Reporter for POLITICO Europe. You can follow his latest work on X.
Russia’s Bomber Forces
Tu-22M3: The Bomber Ukraine Hit With Drones
Major (retd) Michael Shearer
June 12, 2025 at 5:28 am
The British missed an opportunity to reintroduce the .50 coax mounted gun. A reliable weapon that would save on 120 ammunition for engaging light armour.
Pingback: NATO's Challenger 3 Tank Is a Powerhouse on the Battlefield - National Security Journal