As Russian Troops Invaded, Ukraine Scrambled To Form New Mechanized Brigades. A Few Months Later, They Were On The Front.

Mechanized brigades with their heavily-armed infantry, scores of armored vehicles plus organic artillery and air-defenses are the backbone of a modern army.

The Ukrainian army had 13 such brigades when Russia widened its war on Ukraine back in late February. As the Russians advanced, the defense ministry in Kyiv scrambled to stand up at least six new mechanized brigades. First to bolster the army’s mobile defense through the summer, and then to add weight to the fall counteroffensive.

The challenge, besides manpower, was equipment. A brigade might have four front-line battalions, each with several dozen fighting vehicles or tanks and 300 or 400 soldiers. Then there are the howitzers, air-defense vehicles, engineering vehicles, ambulances and supply trucks. All told, a mechanized brigade might have hundreds of wheeled and tracked vehicles.

Kyiv stood up new mechanized brigades as fast as it could recruit and train troops and source vehicles. Ukraine’s foreign allies assisted with both. NATO countries have trained tens of thousands of Ukrainian recruits. Alliance members also have opened up warehouses to find the hundreds of vehicles the new brigades require.

Ukraine’s newer mechanized brigades are hybrids. Where older brigades fight mostly with ex-Soviet equipment—T-64 tanks, BMP fighting vehicles, MT-LB armored tractors, 2S1 and 2S3 howitzers—the brigades that formed in 2022 ride in eclectic mixes of ex-Soviet and ex-NATO vehicles.

The 66th Mechanized Brigade is one of these baby mechanized brigades. It stood up this spring. Russian state media back in August claimed Russian forces killed a hundred 66th Mechanized Brigade troopers and knocked out 10 of the brigade’s vehicles near Stariye Terny in eastern Ukraine.

Today the brigade is fighting just west of Russian-occupied Severodonetsk, also in the east. Videos the brigade has posted online in recent weeks depict its engineers building a pontoon bridge across a swollen river and one of its anti-tank missile teams knocking out a Russian tank while a drone observes from overhead.

Other videos underscore the brigade’s mix of ex-Soviet and ex-NATO equipment. In one video from October, ex-Soviet ZSU-23-4 tracked anti-aircraft guns belonging to the brigade’s air-defense battalion lower their quad 23-millimeter cannons to strafe enemy ground forces.

The M-113s are the real stars, however. Several videos feature 66th Mechanized Brigade troopers riding in the classic, American-designed armored personnel carriers. The mix of camouflage patterns hints that the brigade has M-113s from U.S. and Lithuanian stocks.

One of the Cold War-vintage M-113’s biggest strengths is its lightness. Weighing just 13 tons—less than a wheeled MaxxPro APC—the M-113 spreads its weight across long tracks instead of short wheels, meaning it can cross rough and muddy terrain without getting stuck.

But that lightness is a problem in a close fight. The M-113 mostly is aluminum. Its hull is vulnerable to heavy machine guns, to say nothing of cannons and artillery.

Kyiv was desperate for armored vehicles for its new mechanized brigades, so it was in no position to say no to offers of M-113s. Given the opportunity—say, after the war—the Ukrainian army might choose to swap out the thin-skinned M-113s for newer and better-protected vehicles.

But they’ll have to do for now. The 66th Mechanized Brigade formed and went to war in the span of just a few months. It took what it could get—and rode off into battle.