Now can we have that in English... please explain what did they actually do
Did you watch the video links?
This is an oil jack
The top part, hinged at rear goes up and down when pumping...moving that vertical rod (near the blue parts) up&down.
Most modern jacks have electric motors and timers to control pumping...some in remote areas (without electrical access) have gasoline (lawnmower type) engines.
But in the old days (and a few still remain...) the jacks were powered by a central powerhouse.
The engine was geared to an offset wheel that created a reciprocal motion...the rod lines (solid metal about the diameter of a large thumb) connected the jacks to the central powerhouse.
The pumper would connect & disconnect different jacks as needed (they didn't all run at once).
Some rod lines ran on the ground (especially when crossing a lease road) and would submerge themselves several inches below the road level because of their reciprocal movement.
Some were elevated (creating enough clearance for a Willys Jeep to get under)...
It was always very interesting to see how they connected the jacks (especially those far away from the powerhouse) by running the rod lines.
My generation has more than a few that lost teeth (or worse) by running into rod lines while riding bicycles, sleds, tobogans...or just running after dark.