Several years ago, I found this in a trade magazine and thought it was hilarious. I’m sure that the wide range of people that read this blog will find a similar application to their walk in life.
From Machine Design, Jan 16, 1997, pg. 211.
The US Standard railroad gauge (distance between the rails) is 4′ 8.5″. Why was that gauge used? Because that is the way they built them in England, and US railroads were built by English expatriates.
Why did the English build them like that? Because the first rail lines were built by those who had built pre-railroad tramways, and thats the gauge they used.
Why did they use that gauge then? Because the people who built the tramways used the same jigs and tools for railroad that they used for building wagons, which used that wheel spacing.
So why did the wagons use that odd wheel spacing? Because thats the spacing of the old wheel ruts.
And who built those old rutted roads? The first long-distance roads in Europe were built by Imperial Rome for their legions.
The roads have been used ever since. And the ruts? The initial ruts which everyone else had to match for fear of destroying their wagons were first made by Roman war chariots. Since the chariots were made for or by Imperial Rome, they all had the same wheel spacing.
Thus, we have the answer to the original question. The US Standard railroad gauge of 4′ 8.5″ comes from the original specifications for an Imperial Roman Army war chariot.
So the next time you are handed a specification and wonder what horses a** came up with it, you may be exactly right. Because the Imperial Roman chariots were made to be just wide enough to accommodate the back-ends of two war horses!