Why is the space between rails of the railway track 4ft and 8.5 inches?

Question

Why is the space between rails of the railway track 4ft and 8.5 inches?

Answer 1

Because the wheels on that train are 4 feet 8.5 inches apart.

Answer 2

It depends on what country you are in. Many have different widths

Answer 3

I heard that it started with the distance apart of the trails of 2 draft animals pulling carts in the roman empire.

Answer 4

I have read that it dates back to the width of the wheel spacing of the Roman chariots of some such thing, but I'm not sure that is correct. It is probably some silly British standard that was developed hundreds of years ago and is still followed today. Sort of like the number of square feet in an acre - 43,560. Where did that oddball number come from?

Answer 5

Because that is the standard gauge most, if not all, american railroads use. Out in the southwestern part of this country, a narrow  gauge of three feet is used so that the trains can take sharp curves, and can travers on mountainous terrain.

Answer 6

Hello, I'm a railroad maintance worker, when you lay a tape measure, from side to side, on the rail the correct measurement is 56-1/2 inches, anything over this could cause a derail, the axles of the train are in these measurements, anything bigger, or smaller will cause the train to derail