Wargaming model in roughly 20mm made from styrofoam and balsa with turrets from a wrecked T.34 and the Minairons T.26 kit
It's about 16 inches - a little short but close enough for (Soviet) government work. A bottle of vodka left on the NKVD inspector's desk works wonders
These vessels from the Volga flotilla helped save Stalingrad
There were transported by rail and saw action on other major rivers such as against the German pontoons bridges over the Dnieper
Figures are from Pegasus Soviet Naval Infantry set
They were even used on the river Spree to provide gunfire support in the battle of Berlin!