This is a RPPC, a Real Photo Post Card, a one-off. The configuration around the “Place Stamp Here” on the back with all four corner triangles pointed up puts its manufacture between 1904 and 1918. I’m no expert on locomotives, but it looks like a Camelback 4-2-2 (note the bull’s horns above the lamp). Or, if I’m looking at it wrong, it could be a 4-6-0 (Clinchfield had four 4-6-0s early on, but no 4-2-2s) If this dates to the mid- to late-teens, this gang could be laying track for the Clinchfield Railroad, which may have occasioned the picture. Or they could be cleaning up a wreck.
The only reason I think it’s Clinchfield is because I bought it locally. Weak reasoning, I suppose.
Blogging the Railroad Tunnels 