Horsing Around

The US standard railroad gauge (distance between the rails) is 4 feet, 8.5 inches, an exceedingly odd number. Why was that gauge used?

Because that's the way they built them in England where they are called railways and English migrants built the US railroads. Why did the English build
them like that?

Because the first rail lines were built by the people who built the pre-railroad tramways, and that is the gauge they used. Why did they use that gauge
then?

Because the people who built the tramways used the same jigs and tools that they used for building wagons, which used the same wheel spacing. 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 the old, long distance roads in England, because that's the spacing of the
wheel ruts. So who built those original roads that became rutted?

Imperial Rome built the first long distance roads in Europe and in England for their legions. The roads have been used ever since. And the ruts in the roads?

Roman war chariots formed the initial ruts, which everyone else had to match for fear of destroying their wagon wheels. Since the chariots were made for
Imperial Rome, they all had the same wheel spacing.

The United States standard railroad gauge of 4 feet, 8.5 inches is derived from the specification for an Imperial Roman war chariot. Specifications and
bureaucracies live forever. The Imperial Roman war chariots were understandably made just wide enough to accommodate the back ends of two horses.

Cut to the present... The Space Shuttle, sitting on its launch pad, has two booster rockets attached to the sides of the main fuel tank. These are solid
rocket boosters (SRBs). Thiokol makes the SRBs at its factory in Utah. The engineers who designed the SRBs wanted 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 this tunnel-which is slightly wider than the railroad track, and remember the railroad track is about as wide as two horses' behinds.

So, a major design feature of the space shuttle, arguably the world's most advanced transportation system was determined two thousand years ago by a
horse's ass. This is pretty much how most government decisions are made!