A position signal light used three illuminated lights to control train movement: three lights lit vertically meant a train could proceed, three lights horizontally meant stop, and three lights diagonally allowed a train to proceed at a reduced speed while prepared to stop at the next signal. This signal light came from the Union Railroad, which serviced all the steel mills of US Steel in the Monongahela Valley. It was donated by the Fuddy Duddy’s Club, a group of Union Railroad retirees who strongly supported the Greenville Railroad Park in its early days.