A bit of history...

----- "The US standard railroad gauge (distance between the rails) is 4 feet, 8.5 inches. That's an exceedingly odd number.


Why was that gauge used? 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 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 that 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 some of the old, long distance roads in England, because that's the spacing of the wheel ruts.


So who built those old rutted roads? Imperial Rome built the first long distance roads in Europe (and England) for their legions.
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 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. Bureaucracies live forever.


So the next time you are handed a specification, procedure, or process and wonder 'What horse's ass came up with it?', you may be exactly right. Imperial Roman army chariots were made just wide enough to accommodate the rear ends of two war horses. Now, the twist to the story:


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, or SRB's. The SRB's are made by Thiokol at their factory in Utah. The engineers who designed the ferred to make them wider, but the SRB's 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 SRB's had to fit through that tunnel. Thtunnel 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" -----

This is a repost from some other source- I have no idea where this came from or who wrote it first. It was emailed to me by one of my favorite professors during my final year at VT.

While being an interesting history lesson, it also illustrates how the standards, sizes and constraints we accept with curious bewilderment each day have long and storied evolutions. 

My personal daily example is the metric/english system...mess. That is really the only way to describe it, a mess. In our modern work we are beholden to these dualing, unrelated measurement systems. I'm going out on a limb here - I'm blaming this one on architects. Every architect I know loves the english system. They are enamored with their 5/8ths and 3/32nds, Ive never met another group of people so loyal to compound fractions. Nearly every day I coordinate with an architect who gives me files in english while every other engineer gives me files in metric. Everything is finalized in metric anyways, so why use the english system to begin with? Because projects have lead architects, not lead engineers, or landscape architects. And when the project is done, its the architects name that goes on it - the same guy who was too troubled to work in the same universe as the other 98% of the world. The examples are endless; of huge errors, 10 million dollar mistakes, and so much time wasted, neither system has a unit to describe it, all because of a few American architects who still go by the length of a dead king's hand, or finger, or whatever it was.

Who knows, you could be setting a precedent today that will have people 2,000 years from now scratching their heads and cursing your name..