Then came John Stevens.[1] Stevens was responsible for converting many American railroads from light to heavy duty. The Duluth South Shore was first. Then the Great Northern and the Rock Island. Then the Panama Railroad for building the Panama Canal. Then Russia, Siberia, China...

[1] https://en.wikipedia.org/wiki/John_Frank_Stevens

Strap rail seems to be often found in older abandoned mines in North America (source: watching hours of TVR Exploring and Mine Explorers -videos on youtube ( https://www.youtube.com/@TVRExploring/videos https://www.youtube.com/channel/UCxhNU-gNyPq2lXA7JhLB90Q/vid... )).