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Origins of Engineering Specifications

This answers the age old question of why do we have to do it this way?


Origins of engineering specs and government decisions.

Ever wonder where engineering specifications come from? The US standard railroad gauge (distance between the rails) is 4 feet, 8.5 inches, an exceedingly odd number.

Why was that gauge used? Because that's the way they built them in England, and the English built the first US railroads.

Why did the English build them like that? Because the first rail lines were built by the people who built the pre-railroad tramways, and that is the gauge they used.

Why did they use that particular gauge then? Because the people who built the tramways used the same jigs and tools that they used for building wagons, which used the same wheel spacing.

Okay! 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 the old, long distance roads in England, because that's the spacing of the wheel ruts in the granite sets.

So, who built those old rutted roads? Imperial Rome built the first long distance roads in Europe (and England) for their legions. The roads have been used ever since.

And the ruts in the roads? Roman war chariots formed the initial ruts, which everyone else chose to match for fear of destroying their wagon wheels. Since the chariots were made for (or by) Imperial Rome, they all had the same wheel spacing.

The United States standard railroad gauge of 4 feet, 8.5 inches is derived from the specification for an Imperial Roman war chariot.

Specifications and Bureaucracies live forever. The Imperial man of war chariots were made just wide enough to accommodate the back ends of two war-horses.

Now let's cut to the present...

The Space Shuttle, sitting on its launch pad, has two booster rockets attached to the sides of the main fuel tank. These are solid rocket boosters, or SRB's. Thiokol builds SRB's at its factory in Utah. The engineers who designed the SRB's wanted to make them a bit fatter, but the SRB's had to be shipped by train from the factory to the launch site.

The railroad line from the factory has to run through a tunnel in the mountains. The SRB's had to fit through that tunnel, which is slightly wider than the railroad track, and the railroad track is about as wide as two horses' behinds.

So.... a major design feature of what is arguably the world's most advanced transportation system was determined two thousand years ago by a horse's ass.

Which is pretty much how most government decisions are still made today.

I love it... It's up there with the air speed of the unladen African swallow.