Railways
Railway swiches and diamonds have guard (aka check rails) to prevent wheels taking the wrong course. Similarly, guard rails may be installed inside the outermost running rails on very sharp curves.
Read more about this topic: Guard Rail
Famous quotes containing the word railways:
“There is nothing in machinery, there is nothing in embankments and railways and iron bridges and engineering devices to oblige them to be ugly. Ugliness is the measure of imperfection.”
—H.G. (Herbert George)