The Challenger 2 Tank Already Has a Lot of Armor. The Ukrainians Added More.

The Ukrainian army has added protection to its British-made Challenger 2 tanks. The add-on armor, on the lower front of the 69-ton, four-person—the “glacis”—clearly is meant to protect one of the tank’s notorious weak spots from tandem warheads, like that on the Russian army’s Kornet anti-tank missile.

The armor, which is visible in a video that appeared online last week, is pointless if a Kornet finds another weak spot. And that’s exactly what apparently happened on or around Sept. 4, when the Russians bagged their first—and so far only—Ukrainian Challenger 2.

The Challenger 2 is one of the world’s better-protected tanks. Its composite “Dorchester” armor—gives it the equivalent of at least 1,400 millimeters of steel on the turret face.

But British Army doctrine for decades asked its tankers to fight defensively, while dug in. For that reason, British tank-designers applied some of the thinnest protection to the glacis, which would be underground when the tank is fighting from a revetment.

It’s not for no reason that, in the 30 years since the Challenger 2 entered service, the British Army has added bolt-on armor to the glacis. Weirdly, the United Kingdom apparently didn’t offer this glacis armor to Ukraine. It’s almost as if British officials expected the Ukrainians to use the Challenger 2 defensively.

The problem for the Ukrainian 82nd Air Assault Brigade—the sole user of Ukraine’s 14, now 13, Challenger 2s—is that it’s fighting offensively. It’s the lead brigade in a division-size force attacking on the 50-mile axis from Robotyne to Melitopol in Russian-occupied southern Ukraine.

So it makes sense that the Ukrainians improvised their own add-on glacis armor. They knew their Challenger 2s would be advancing.

In mid-August, the 82nd and adjacent brigades liberated Robotyne—and then pivoted southeast to assault the next Russian strongpoint in Verbove. It seems the Challenger 2 struck a mine while shifting positions from outside Robotyne to outside Verbove.

Immobilized by the mine strike, the Challenger 2 was an easy target. The crew bailed out and, not long after, a Russian Kornet anti-tank missile struck the idle, unoccupied tank.

The four-foot Kornet packs a 10-pound tandem warhead. Basically, the first warhead punches a hole in a vehicle’s outer armor. The second warhead explodes inside the vehicle.

If the Kornet had struck the immobile tank on its glacis, where the Ukrainians had reinforced the armor, the tank may have survived. Instead, it seems the missile’s operators used the “top-attack” function. The missile’s tandem warhead exploded slightly above the Challenger 2’s turret, where the armor also is thin—and where there isn’t any additive armor.

The missile strike triggered a fire that apparently cooked off the Challenger 2’s ammunition charges in their special containers. Filled with water, these containers are supposed to prevent catastrophic secondary explosions. In this case, they failed—and the resulting blast wrenched the Challenger 2’s turret from its hull.

It wasn’t a meteoric “turret toss,” as often happens with Soviet-style tanks, which store their ammunition dry and under the turret. But it still was a kind of worst-case scenario for a Challenger 2. The Russians hit it twice in exactly the right spots: first striking the tracks with a mine and immobilizing the vehicle, then striking the turret top where the protection is minimal.

So now the Russians know how to kill a Challenger 2. Strand it, then plink it from above.

But this lesson cuts both ways. The Ukrainians already appreciated one of the Challenger 2’s weaknesses: its glacis. Now they should appreciate another. Its turret top. Especially when the tank can’t move, and get under cover.