A question about logging railroads........

[WoundedBear]

What is the purpose or reason for what appears to be, a third rail in this photo?

[Stephen D. Richards]

Logging railroads, at least in the Appalachians, would often lay two sets of rails in different gauges to allow the standard gauge and the narrow gauge to run the same road.  Hope that helps.   Stephen

[Nathan]

Some roads also put in guard rails in areas that equipment had trouble staying on the track.

[Karl Reichenbach]

The photo is a guard rail.

Karl

[WoundedBear]

Thank you, Gents.

[ebtnut]

Yes, those are guard rails to help keep the cars on the track on tight logging curves.  That photo looks like WVP&P territory out near Cass.