18" Track Spacing was never used on MAINLINE trackage for any railroad in America that I have heard of but was used underground in mining operations all over the world. I know where there is an 18" hand push mining cart from the Magdalena mines of New Mexico in the front yard of a residence in Tulrosa New Mexico.

18" Track Spacing is used by many Amusement Park Train Rides as it is approximately 1/3 size scale.

A hand pushed mining cart salvage from the Magdalena Mines of New Mexico.