A Milpitas Mom’s Favorite Joke.
or How MilSpecs Live Forever
The US standard railroad gauge (distance between the rails) is 4 ft 8 1/2 in (1.44 m). That’s an exceedingly odd number. Why is that gauge used? Because that’s the way they built them in England, and the US railroads were built by English ex-patriots.
Why did the English build ’em 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 as they used for building wagons, which used that wheel spacing.
OK! Why did the wagons use that wheel spacing? Well, if they tried to use any other spacing the wagons would break on some of the old, long distance roads, because that’s the spacing of the ruts.
So who built these old rutted roads? The first long distance roads in Europe were built by Imperial Rome for the benefit of their legions. The roads have been used ever since. And the ruts? The initial ruts, which everyone else had to match for fear of breaking their wagons, were first made by Roman war chariots. Since the chariots were made by or for Imperial Rome they were all alike in the matter of wheel spacing (ruts again).
Thus we have the answer to the original question. The United States standard railroad gauge of 4 ft 8 1/2 in derives from the original military specification (MilSpec) for an Imperial Roman army war chariot. MisSpecs (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 chariots were made to be just wide enough to accommodate the back-ends of two war horses.
A follow-up to this story: When Napoleon marched on Russia, his army made much slower time than planned once they reached eastern Europe because the ruts weren’t to Roman gauge. Because they made slower time than planned they got caught in the field in the Russian winter rather than on the outskirts of Moscow. And then, of course, they lost the war.
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 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.