You've caught my attention.

And the values seems realistic:

Needs: 30 workers, Maintenance II (22/mo),
10 MW electricity. <-- On that i am not shure if it was for the whole unit. Or only for one side of the tracks. I know someone in the coal department i ask him.

I would appreciate it. Thanks!
Currently, the excavator model and behavior are simple, so in the future I want to upgrade them.