Ukraine has 14 kinds of howitzers to batter Russian forces, but each gun brings a new problem for Kyiv

• Ukraine has amassed a polyglot arsenal of artillery thanks to donations from its foreign partners.
• Those howitzers are a key source of firepower and have battered Russian forces to nearly 18 months.
• But sustaining and maintaining each kind of artillery presents a problem for Ukrainian troops.

Artillery has become Ukraine's deadliest and most prolific weapon against Russia. One reason for that is Ukraine's army has managed to integrate more than a dozen kinds of Western guns into its pre-war arsenal of Soviet-era cannons.

But this menagerie of firepower creates a logistical nightmare. While it is not uncommon for today's armies — especially those of developing countries — to have weapons from multiple nations, Ukraine's diversity of arms is staggering.

"Most countries have two or three different howitzer types in their land forces. Ukraine has 14," Patrick Hinton, a British Army captain, wrote in a recent article on Ukrainian artillery for the Royal United Services Institute, a British think tank.

Merely tallying the howitzers fielded by Ukraine is a challenge. A report by the Center for Strategic and International Studies, a US think tank, lists 13 foreign-made 155 mm howitzer models donated or co-donated by 15 countries as of January, for a total of at least 352 155 mm artillery pieces.

That number has certain to have grown, not least because "the exact number is likely a bit higher since some countries do not disclose their transfers," the CSIS report noted.

Ukraine's arsenal of towed 155 mm howitzers includes the US M777, British AS-90, France's TRF1, and the British-German-Italian FH-70.

For armored self-propelled 155 mm howitzers, Ukraine has received three variants of the American-made M109, plus Germany's PzH 2000, Poland's Krab, and Slovakia's Zuzana 2.

To add to the mix, there is France's truck-mounted 155 mm Caesar gun and Lithuania has sent old US-made M101 towed 105 mm howitzers that were designed in 1941.

And that's just Western-designed weapons. Ukraine's army has an array of Soviet-era artillery, including the 2S7 self-propelled 203 mm howitzer; the 2S3, 2S5, 2S19, and Czech-made M-77 152 mm self-propelled howitzers; as well as an assortment of towed 152 mm and 122 mm guns.

Crash courses

Just getting the right ammunition for that arsenal is a major challenge. Ukraine's Soviet-designed howitzers fire Russian-standard 152 mm shells, which are hard to find, while its Western-made guns fire NATO-standard 155 mm rounds, of which Western countries are struggling to increase production.

The difference in caliber creates many opportunities for the wrong ammunition to be sent to Ukrainian gunners. The right caliber also isn't a guarantee of quality, as cannons and munitions are built to differing standards.

Even seemingly similar howitzers can have minor but significant differences that affect their accuracy against targets 10 or 20 miles away. For example, some NATO-standard 155 mm guns made by different nations are more compatible with some shells than with others.

Cannon also wear out over time, especially when in intense use by crews still learning how to operate unfamiliar weapons.

"The accelerated crash courses provided to Ukrainian crewmen allowed them to fight effectively, but left them without the sustainment skills to look after and get the maximum operational lifespan out of artillery systems which are expensive, slow to manufacture, and difficult to replace," noted another RUSI analysis.

Howitzer barrels can fire 1,500 to 2,500 rounds before they need to be replaced, which "is easier said than done," Hinton wrote. "The UK is unable to manufacture 155-mm gun barrels, and there are few manufacturers in Europe with the capability to do so."

US-operated help lines aid Ukrainian troops with their new weapons — in some cases while those weapons are being used in combat — but logistical and maintenance issues persist.

Even if ammo were in ample supply, getting it to Ukraine's 1,500 or so howitzers would be challenge enough.

Ever since World War I, big guns have been notorious for devouring huge quantities of shells. Moving those bulky shells over crowded roads, across tough terrain, in bad weather, and through enemy fire is a hassle for supply trucks.

Rapid advances — like the one seen during Ukraine's counteroffensive last year — can also strain an army's ability to keep shells flowing over longer supply lines.

Many of Ukraine's tank-like self-propelled guns also need distinct spare parts and electronic components, as they have been provided by different countries, which presents perhaps the most insidious challenge of Ukraine's multinational artillery park. Using multiple kinds of foreign-made howitzers means depending on multiple supply chains — each susceptible to manufacturing, transportation, and political breakdowns largely outside of Kyiv's control.

But Ukrainian troops need every weapon they can get, and their commanders likely see the benefit of a polyglot arsenal as well worth the hassle.

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.