I often visited Dinorwic slate quarry when I lived in North Wales.
The slate quarry is now a museum, and features as one of its star attractions some preserved quarry locos. The little locos now take tourists around the lake, but they were previously employed moving the slate around the mountain. The had a remarkable long life - from the tail end of the 19th Century up until the quarry closing in the late 1960s. This is a painting of an Alice class 0-4-0 quarry loco sitting in a tunnel awaiting action.
It is painted with a palette knife which I hope captures the little workhorse and its rough conditions.
artist quality oil paints on gessoed board