The U.S. Standard railroad gaug(distance between rails) is 4 feet, 8.5 inches. That’s an exceedingly odd number.
Why was that gauge used?
rail lines were built by the same people who built the pre-railroad tramways, and that’s the gauge they used.
Why did the wagons have that particular Odd wheel spacing?
Well, 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 ..
Imperial Rome built the first long distance roads in Europe (including England) for their legions. Those roads have been used ever since.
And the ruts in the roads?
they were all alike in the matter of wheel spacing. Therefore, the United States standard railroad gauge of 4 feet, 8.5 inches is derived from the original specifications for an Imperial Roman war chariot. In other words, bureaucracies live forever.
The engineers who designed the SRBs would have preferred to make them a bit larger, 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, and the SRBs had to it 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.
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.
Explains a whole lot of stuff, doesn’t it?