The coal fired steam engines (locomotives) of the Sandaoling coal mine in China. These are China’s Jeaious Class Locomotives and
only still used here. I’ll bet they don’t have a problem with vegetation encroaching on the tracks.
When pulling 50 coal cars for 3 miles up a pretty steep grade out of the mine pit, the best they can do is 30 kph (18.6 mph).
These engines are scheduled to be shut down, along with the mine in 2020, as China moves to cleaner energy.
They say one of these engines goes by ever 10 minutes or so.
50 coal cars, every ten minutes, night and day, that’s a lot of coal, and a lot of energy to replace.
If you want to see a video of them in action I’m posting one in the Choo Choo thread
over here.