In 1930s the Russian army was obsessed with the idea of creating huge planes. At that time, they were proposed to have as many propellers as possible to help carry those huge flying fortresses into the air. Jet propulsion has not been implemented yet Not many photos were saved from that time, because of the high secrecy levels of such projects.
The weaponry carried by this behemoth is shown in the last two pics! I wonder if it got 75 gallons per mile ?.........Kinda' looks like a Buick ?