Road regulations must be observed underground too. You don't think anymore that you know everything about the Moscow Metro after reading our previous articles about it, do you (1, 2)? Do you want to find out more about it and its utility lines? So, go ahead!
With these enormous ventilators they ventilate the tunnels and stations of the metro.
The ventilators from behind.
These shutters regulate the air stream.
With this hermetic door, they could cut off the venting channel in case of a war or an anthropogenic accident.
This is how all metro tracks end.