The Western-made tanks heading to Ukraine are unique — but that creates unique problems for Ukraine's military

• Three kinds of Western tanks now are headed to Ukraine, and more may follow.

Military supply officers have a tough job. Modern tanks are complex and require lots of maintenance and spare parts.

But what do you when your army is equipped with a half-dozen types of main battle tanks, each with its quirks and requirements? That's the situation faced by Ukraine.

With three models of Western main battle tanks from three different nations on the way — and possibly more on the horizon — Ukrainian tank crews, mechanics, and quartermasters will have to learn to accommodate a variety of armored idiosyncrasies.

M1A2 Abrams

Take the US M1A2 Abrams, of which Ukraine is slated to receive 31. While most modern tanks run on diesel, the Abrams uses a Honeywell 1,500-horsepower gas-turbine engine that functions best when burning JP-8 jet fuel.

This gives the Abrams a powerful power plant capable of brisk acceleration while remaining remarkably quiet. But the price is ferocious gas-guzzling.

The Abrams gets about 0.6 miles per gallon. In 1993, Sweden compared the M1 to the Leopard 2, and found the German tank got double the Abrams' gas mileage.

Compounding the problem is that Ukraine's pre-war fleet of Soviet- and Russian-designed tanks, as well as the German Leopard 2s and British Challenger 2s it is receiving, run on diesel.

This means that Ukraine will have to ensure a separate fuel supply for the Abrams. (Abrams tanks can use diesel but doing so creates additional maintenance needs.)

Challenger 2

Then there is Britain's Challenger 2, of which Ukraine will get 14. While most tanks today are armed with smoothbore cannon, the Challenger 2 has a rifled L30 120 mm cannon.

Most tank guns use hollow-charge or armor-piercing fin-stabilized discarding-sabot (APFSDS) rounds that punch through the armor of enemy tanks.

But the Challenger 2 can also fire high-explosive squash head (HESH) shells that essentially plant a big charge of plastic explosive on the surface of the target tank, which causes the inner armor to spew fragments that wound or kill the crew and set off ammunition.

HESH rounds are particularly suited for rifled cannon, but this means Challengers need a different type of ammunition than the Abrams and Leopard 2, which can share some ammo.

Also unusual is that the L30's shells come in two pieces (explosive and propellant) rather than a unitary shell. While that offers some advantages in safety and stowage, Ukrainian gunners and loaders will have to learn new procedures to use them.

The Challenger 2 also consists of a modernized Challenger 1 hull from the 1990s and a new turret. An unfortunate consequence of that combination is that the Challenger 2 "requires at least two sets of tools because the turret uses metric measurements and the hull imperial," noted Britain's Daily Telegraph.

However, it is not true that the Challenger 2 comes with a built-in teapot.

Leopard 2

Then there is the German-made Leopard 2, which hasn't seen much combat.

The Abrams and the Challenger 2's predecessor, the Challenger 1, saw a fair bit of combat against Iraq's T-72 and other Russian tanks in the First Gulf War. Challenger tanks were credited with destroying 300 Iraqi tanks.

When Turkish Leopard 2s battled ISIS fighters in Syria in 2016, the results were less than impressive.

Turkey's 2nd Armored Brigade reportedly lost 10 Leopards "in the fight for the Syrian city of al-Bab to anti-tank weapons and improvised explosives," according to German magazine Der Spiegel. "Islamic State terrorists began using images of the burned-out tanks in their propaganda material."

Most likely, these losses were because of poor Turkish combined-arms tactics rather than any glaring deficiencies with the Leopard 2. (Iraqi and Saudi M1s have been destroyed for the same reason.)

The question with the Leopard 2 may be maintenance and availability.

The Bundeswehr, which has long struggled with readiness and spare parts issues, only has 350 Leopard 2s, which doesn't leave many for Ukraine.

Leopard manufacturer Rheinmetall has 22 Leopard 2s and 88 older Leopard 1s in its inventory, but those can't be made battle-ready until at least 2024.

Useful, but challenging

To be clear, a quirk is not necessarily a flaw. And there are perfectly valid reasons why tanks differ between nations.

For example, HESH rounds are best suited for a rifled cannon, and gas-turbine engines are not an unreasonable choice for armies willing to pay the logistical price.

In the end, what will be key isn't the technical characteristics of these tanks. They are all formidable and better than the Russian tanks they will be facing.

What matters is how many Ukraine will receive — 31 Abrams and 14 Challenger 2s are not a lot — and how Ukraine's military uses them.

Michael Peck is a defense writer whose work has appeared in Forbes, Defense News, Foreign Policy magazine, and other publications. He holds a master's in political science. Follow him on Twitter and LinkedIn.