4-axle OK-type artillery Wagon – Finnish Armored Train – photo 2026During the Continuation War, Finnish armored trains used modified 4-axle OK-type artillery wagons rearmed with 40mm Bofors anti-aircraft guns (designated 40 ItK/39 B), alongside secondary Maxim machine guns. The original closed turrets were removed and open-top configurations were adopted to improve anti-aircraft defense. The gun platform was built in a 4-axle O-series timber flatcars approximately 14 meter long, fitted with riveted steel armor plates. The closed roofs and original turrets were removed or altered to mount the 40mm Bofors (40 ItK/39 B) as primary anti-aircraft armament.
It was outfitted with multiple water-cooled 7.62mm Maxim M/09 machine guns for both anti-aircraft and surface defense through side portholes but lacked gun-specific mechanical computers, utilizing simpler domestic Finnish anti-aircraft sights instead.
The 4-axle OK-type artillery was used on Finnish Armored Trains (Train 1 and Train 2) and the 1st Railway Anti-Aircraft Battery during operations against Soviet air and ground forces.
In the photos you see the last remaining modified 4-axle artillery wagon, it is preserved and displayed at the Parola Armour Museum in Finland.
