Check this out:
The US standard railroad distance between the rails is 4 feet, 8.5 inches which is a strange number. Why this distance? Because that’s the way they built them in England, and English expatriates built the US Railroads.
Why did the English build them like that? Because the first rail lines were built by the same people who built the pre-railroad tramways, and that’s the distance they used. The people who built the tramways used the same jigs and tools that they used for building wagons, which used that wheel spacing. Wagons have particular odd wheel spacing, because if they tried to use any other spacing, the wagon wheels would break on some of the old, long distance roads in England, because that’s the spacing of the wheel ruts.
Those old rutted roads were build by Imperial Rome. They built all the first long distance roads in Europe (and England) for their legions. The roads have been used ever since. The ruts in the road were formed by Roman war chariots. Because of the ruts, everyone else had to match for fear of destroying their wagon wheels.
The United States standard railroad gauge of 4 feet, 8.5 inches is derived from the original specifications for an Imperial Roman war chariot. And bureaucracies live forever.
So, the next time you are handed a specification and wonder what horse’s ass came up with it, you may be exactly right, because the Imperial Roman army were made just wide enough to accommodate the back ends of two war horses. Crazy, eh.
Now get this —- When you see a Space Shuttle sitting on its launch pad, there are two big booster rockets attached to the sides of the main fuel tank. These are solid rocket boosters (SRBs). The SRBs are made by Thiokol at their factory at Utah. The engineers who designed the SRBs would have preferred to make them a bit fatter, but the SRBs had to be shipped by train from the factory to the launch site.
The railroad line from the factory happens to run through a tunnel in the mountains. The SRBs had to fit through that tunnel. The tunnel is slightly wider than the railroad track, and the railroad track, as you now know, is about as wide as two horses’ behinds. So, a major Space Shuttle design feature of what is arguably the world’s most advanced transportation system was determined over two thousand years ago by the width of a horse’s ass.