Rocket Boosters and Horse Butts

Horse Chariot

Editors Note:  I published this on my blog in about October of 2011 on another blog I maintained.  I’ve chosen to keep it around for it’s comical and educational value. 
There was an amazing story that was was passed around around 2000 that I always found fascinating .  There are several slight variations to the story, so I picked one, and edited for clarity, but left the original intent intact.

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

Because that is the way they built them in England, and the U.S. railroads were built by English expatriates.

Why did the English people 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. Okay!

Why did the wagons use that odd 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 is the spacing of the old wheel ruts.

So, who built those 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 destroying their wagons, were first made by Roman war chariots. Since the chariots were made for or by Imperial Rome, they were all alike in the matter of wheel spacing.

So, why did the Romans pick that spacing?

Because the Imperial Roman chariots were made to be just wide enough to accommodate the backends of two horses.

How this effected the space shuttle program :

The engineers who designed the solid rocket boosters, or 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 to 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,in summary, a major design feature of the world’s most advanced transportation system was determined by the width of two horses’ behinds!!

It has been suggested that this story is both true and false, but in general, considered to be true in the sense that tracks and roads are always going to be built to the size of the transportation vehicle using it.

What I find most fascninating about this is not that a horse’s butt was the guage used for the shuttle’s rocket boosters, but that this represents a pattern in life that can be quite frustrating.

A recent example is the LED bulb, that can use the standard socket we have today, but it’s far from optimal from doing it.  They had to be specially fitted with fins, and the original designs all had differerent socket plans that had to be nixed in favor of using the existing infrastructure.

Anyhow, I hope you got a kick out of the horses butt story – true or not!

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