This train is not a regular train! You can’t travel by it, but someone is definitely working while on it.
Actually, it’s a special train, used for polishing the rails.
A control system is directing the special wheels that are used for polishing.
The wheels are abrasive and can be set on different angles, in order to polish the surface of the rails in different manners.
This system is meant to eliminate unevenness and make the tracks smoother.
Feel free to share