Vintage work crew photos

[Frank S]

Oh of course! It's a rail shop.
Not gears, they are faceplates, a locomotive wheel visible toward viewer; possibly turning mounted wheels.
To busy critiquing bad lighting, forgot good parts of photograph.
Still cone-drive, running a jack shaft, to get realistic RPM. The final drive is teeth on face plate. Begs the question, how big a vertical shaper cut those teeth? This could be still half a generation before large mills.

Yes and the large diameter of the faceplates were to accommodate the drive wheels of the big steam locomotives