Signal Bridge Question

[Stitch]

This is more of a history question. In the below picture to the right of the signal lights there are two empty Light/Signal brackets and one to the left. Any idea if they were ever used for signals in the past? More industrial business? Also the track closest to the right would this track what conductor would refer to as the third rail?

[csxt4617]

I would guess that there probably was never one to the left, and most likely none on the right either. The bridge is just that wide because of the siding on the right side. They build a bridge rather than a left side cantilever. I think the extra piece at the bottom is just part of the truss structure of the bridge, not necessarily part of a signal bracket.