This is the Zaamurets, a land cruising battleship. It was one of many modified or purpose-built war trains that carried destruction on rails. James Simpson tells its story in a longform article at Medium. From 1916 to the 1920s, it served (by my count) at least seven different armies in battles across the breadth of Eurasia.
Tsarist Russia constructed this behemoth, which originally had 2 traversable turrets with 57 mm guns, 8 machine guns, and a top speed of 28 miles per hour. In the midst of the Russian Revolution, it fell into the hands of the Communists, then into the legendary Czechoslovak Legion in its Anabasis-like march across the whole of Russia, then the White Russians, then an assortment of Chinese warlords, and finally the Japanese before disappearing into history. It’s an amazing story that you can read in full here.
-via Ace of Spades HQ