How a Horse's Rear End Affects the Space Program

Contributed by Chris O'Rourke
December, 1999

The US Standard railroad gauge (the distance between the rails) is 4 feet, 8 ½ inches.

This is an exceedingly odd number. Why is that gauge used?   What reason would any decent engineer in his or her right mind choose such an impractical distance?

The answer is due to the fact that this is the way they built the train tracks originally in England and the USA railroads were built by English expatriates. Ah. But...Why did the English build them like that in the first place? 

It seems the reason can be traced even further back. The first railway lines were built by the same people who built the pre-railroad tramways, and that’s the gauge they used.  Okay, fine, but why did they use that impractical gauge in England back at the start of things?

Because the people who built the tramways used the same jigs and tools that they used for building wagons, which used that wheel spacing.  Okay, but...Why did their wagons use that odd wheel spacing? 

Because if they tried to use any other spacing the wagon wheels would break on some of the old, long distance roads. All the old roads had deep wheel ruts that the wagon wheel spacing had to conform to or be ruined. So who built these stupid old rutted roads?  It turns out it was Caesar's fault. Probably that is who you suspected in the first place.

It seems the first long distance roads in Europe were built by Imperial Rome for the benefit of their legions. The Roman roads have been used ever since. And the  ruts?  

The original ruts, which everyone else had to match for fear of destroying their wagons, were first made by the wheels of Roman war chariots.  Since the chariots were made for or by Imperial Rome they were all alike in the matter of wheel spacing.

Thus, we have the answer to the original question. The United States standard railroad gauge of 4 feet, 8 ½ inches derives from the original specification for an Imperial Roman army war chariot.

Specifications 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 just wide enough to accommodate the rear ends of two war-horses !!

Now it seems the Roman Empire will even have an effect on our Space Program, thus giving yet another possible explanation for our recent fiascos in space.

It turns out there is an interesting extension of the story about railroad gauge and horses’ behinds. When we see a Space Shuttle sitting on the launch pad, there are two big booster rockets attached to the sides of the main fuel tank. These are the solid rocket boosters, or SRBs.

The SRBs are made by Thiokol at a   factory in Utah. The engineers who designed the SRBs might 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 from the factory runs through a tunnel in the mountains. The SRBs had to fit through that tunnel.

The tunnel is slightly wider than a railroad track, and the railroad track is about as wide as two horses’ behinds.

So there you have it. The major design feature of the world’s most advanced transportation system was originally determined by the width of a horse’s ass.

It makes you wonder what the world would be like today if Hannibal had beaten Rome with those Elephants...