Driving across the Cumberland Plateau on our way to the Ozone Falls we saw this interesting old wooden trestle. As I approached the tracks a distant train whistle sounded and a few minutes later this engine, with an interesting livery, appeared pulling several car. Lhoist is, among other things, is a mining concern. This line is only 15 miles but it serves a vital link from one of their major mines to an interchange for other main line rail service. The wooden trestles are more sturdy and there are more of them than I knew, according to at least one railfan.