The United States’ standard railroad gauge, that is, the distance between the rails, is four feet, eight and a half inches. That is an exceedingly odd number. Why four feet, eight and a half inches? Why was that gauge used? It was used because that’s the way they built them in England, and English expatriates built the United States’ railroads.
So now you might ask, “Okay, why did the English build them like that?” The first railroad lines in England were built by the same people who built the pre-railroad tramways, and that is the gauge they used. And why did they use that gauge? The people who built the tramways used the same patterns, templates, and tools that were used for building wagons, which used that same wheel spacing.
Now you’re probably wondering, “Why did the wagons have that particularly odd spacing?” Well, if any other spacing had been used, the wagon wheels would have broken on some of the old, long-distance roads in England since that’s the spacing of the wheel ruts in the roads.
So you wonder, “Who put the ruts in the roads?” The first long-distance roads in England were built by Imperial Rome for its legions. The roads have been used ever since. And the ruts? It was the Roman war chariots that made the initial ruts, and everyone else had to match them out of fear that their wagons and wagon wheels would be destroyed. Since the chariots were made by Rome, they all had the same wheel spacing. And the Roman war chariots were just wide enough to accommodate the back ends of two warhorses.
Thus we have the answer to the original question: the United States’ standard railroad gauge of four feet, eight and a half inches was derived from the width of the rears of two horses, which powered an imperial Roman chariot.
As ridiculous as this seems, there’s more. Here is the rest of the story: When we see the space shuttle sitting on its launch pad, we see two big booster rockets attached to the sides of the main fuel tank. These are the solid rocket boosters or SRBs. Thiakol makes the SRBs in its factory in Utah.
Rumor has it that the engineers who designed the SRBs might have preferred to make them a bit fatter. But the SRBs had to be shipped by train from the factory to the launch pad. The railroad from the factory ran through a tunnel in the mountains, and the SRBs had to fit through that tunnel. The tunnel is slightly wider than the railroad track, and the track is about as wide as two horses’ behinds. So the major design feature of what is arguably the world’s most advanced transportation system was determined by the width of two horses’ rears! (Some say that this story isn’t true, but because it proves a great point, we love to use it!)
Cited in Cat & Dog Theology: Rethinking our relationship with our master; Living passionately for the glory of God, by Bob Sjogren & Gerald Robison