The Book of Armaments:
German Heavy Guns
by Mike Bennighof, Ph.D.
July 2020

While the pictures of German blitzkrieg usually include dive bombers and panzers, they rarely show the big artillery pieces that gave the spearheads their firepower. Rather than hold back their heavy guns for static warfare, the Germans attached corps- and army-level batteries and battalions to the mobile formations.

That firepower added to the heavy metal already wielded by the organic artillery regiments. Where the French and Poles armed their light artillery battalions with the old but proven 75mm Model 1897 field gun, the Germans wielded the far more powerful FH18 105mm howitzer, which tossed a shell three times the size of the old gun’s round. Likewise, the German medium battalions had a very effective 150mm piece, where the Allied equivalent was a 105mm weapon (one less effective than the German 105mm).

But beyond those guns, the Germans deployed even larger weapons in their corps and army battalions. The Reichswehr, the army of the Weimar Republic, made a point of retaining the cadre of professional artillery specialists built up during the Great War. The Versailles treaty forbade possession of artillery pieces larger than 105mm in caliber, but could not proscribe planning and paper exercises, or the design of new weapons.

Germany retained a few heavy artillery pieces, hidden away in secret locations where the Disarmament Commission could not find them. When the Nazi regime openly declared re-armament, that handful of guns - 21cm Mörser 16, or 210mm heavy siege howitzers - would equip the first heavy batteries.

Though at the cutting edge of artillery technology when introduced in 1916, by 1939 the Mörser 16 showed its age despite modernization. The old-style heavy spoked wheels with their “feet” to give added ground contact gave way to modern steel wheels and rubber tires. A limber was added, also with road wheels, to allow the weapon to be towed as a single piece (when drawn by horses in its original configuration, the barrel had been transported separately).

A battery of 21cm Mörser 18, on the road to Stalingrad, September 1942.

In 1939 the German Army began to take delivery of a new heavy howitzer, the 21cm Mörser 18. This was a more modern gun with better range, but its carriage introduced many new features. Most notably, it re-introduced the dual-recoil system pioneered in the Vickers-Terni 75/27 cannon built for the Italian Army starting in 1911. The Italian gun had proven too difficult to manufacture and the system had been abandoned after this sole use.

In the German design, the two recoil mechanisms were well-separated, unlike the old Italian gun. The barrel slid in its cradle, as in a traditional single-recoil mechanism, and a second mechanism at the bottom of the carriage had its own set of hydraulics. That caused the top of the carriage to recoil as well as the barrel, and required a lengthy preparation time when the gun was initially emplaced (the carriage would be lowered to the ground on a firing platform, with the wheels jacked up off the ground), but provided an extremely stable firing platform.

The heavy howitzer entered production in 1939, and would be briefly cancelled in 1942 to shift priority to the 170mm cannon before resuming in 1943. Over 700 of them were built, seeing action on every front.

While the 210mm heavy howitzer offered only incremental improvement, the 170mm Kanone 18, known as the “Matterhorn,” marked a considerable step forward. The gun featured an extremely long barrel, offering great accuracy, and when matched with the 21cm Mörser 18’s innovative carriage it had a very stable platform from which to fire (assuring that the gun would not have to be re-adjusted once it had found its target).

New ammunition developed for the Kanone 18 offered explosive power almost as great as the 210mm shells of the Mörser 18. The gun had three standard types of ammunition: a high-explosive shell, a long-range shell with a ballistic cap, and an armor-piercing round capable of penetrating 10 inches (254mm) of armor, more than any existing tank. None of these seem to have been actually fired at enemy tanks, and this round may not have been issued very often.

But the new gun’s real advantage was its extremely long range - nearly 30 kilometers - and ability to fire accurately over that distance. That out-ranged anything in the Allied arsenal, and made the Kanone 18 a formidable counter-battery weapon. The explosive power of its rounds allowed it to fill the same heavy-support role as the Mörser 18, and that led to the temporary cancellation of the bigger gun’s production. Instead the Kanone 18’s production line would be shifted to Hanomag while Krupp resumed making the Mörser 18.

A 17 cm Kanone 18 emplaced outside the Anzio beachhead.

Just over 330 examples of the Kanone 18 were built. Despite its ultra-long range, many of these were lost in action thanks to the excruciatingly long process to limber them for transport and the slow speed of their SdKfz 9 prime movers once encumbered by the twin load (barrel and carriage).

While the old Mörser 16 had been drawn by horses during the Great War, from the start the new generation of German heavy artillery had motorized prime movers (the Hanomag-built SdKfz 9 half-track for the most part, which could also carry the full 10-man crew). Despite the half-tracked prime movers their off-road capability was essentially non-existent as the guns’ weight limited them to road travel. But this still made their batteries and battalions nominally “motorized” units, even if little faster than marching infantry, and they often were attached to panzer divisions during the 1941 and 1942 offensives on the Eastern Front. That gave the armored troops extraordinary additional firepower, at least on paper, if the big guns could catch up with the tanks and trucks.

The big guns have appeared in Panzer Grenadier games since the earliest volumes of the series, but never with their own pieces - they formed part of the “Off-Board Artillery” that players can use. That changes with The Book of Armaments: Eastern Front Artillery, which has pieces for all of them. They’re still used off-board for the most part, but now each player can track their use with the actual playing pieces, which isn’t strictly necessary (you can still get by just writing them down when used) but is enormously more fun.

You can order The Book of Armaments: Eastern Front Artillery right here.

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Mike Bennighof is president of Avalanche Press and holds a doctorate in history from Emory University. A Fulbright Scholar and NASA Journalist in Space finalist, he has published eleventy-million books, games and articles on historical subjects. He lives in Birmingham, Alabama with his wife, three children, his dog Leopold and Egbert the pet turkey.

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