Reliable mechanism of the Soviet hours

In the early 20-ies of plans for life was enormous, requiring a time reference for its Soviet watches.
The uniqueness of the Soviet watch is that for 60 years (from the 30's until the perestroika in the 90s) we are one of the most backward countries in the world at the time production came on 2-3 place in the world watch-making for household purposes.
Soviet watches did not disappear together with the Soviet Union, they continue their course steadily ticking through the times and epochs.