Antique Otis Elevator Machine Room. 600 VOLTS DC! 

I have not seen this type of winding drum machine before, with the floor selector contacts open in the front. I did not hear an MG set running (unless it's elsewhere) likely had a DC rectifier in the controller board. 600VDC was not unheard of depending on the type of controller. The most recent Otis basement winding drum I saw during a behind the scene tour from 1914 was 260VAC 3 phase, DC rectifier in controller.

That's some really nice arcing on those contactors

I saw something very similar to that in the institute of mechanical engineers, birdcage walk

Wow

the strings needs replacement.... the left part of it have damage.......