Standards
Did you know that the U.S. standard
railroad gauge, the 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 were built in England, and U.S. railroads were
built by English expatriates.
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'd used for building wagons that used that wheel spacing.
Okay, why did the wagons have that
particularly odd wheel spacing? Well, if they tried to use any other
wheel spacing, the wagon wheels would break on some of the old
long-distance roads in England,
because that was the spacing of the wheel ruts.
So, who built those old rutted roads?
The first long distance roads in Europe and in England were built
by Imperial Rome for its Legions. The roads had been used ever since.
And the ruts in the roads, the
initial ruts which everyone else had to match for fear of destroying
their wagon wheels, were first
formed by Roman war chariots. Since the chariots were made for or by
Imperial Rome, they were all
alike in the matter of wheel spacing.
The U.S. standard railroad spacing - 4
feet, 8.5 inches - is derived from the original specifications for an
Imperial Roman war chariot. Specifications and bureaucracies live
forever.
So, the next time you are handed a
specification, and wonder what horse's-behind came up with it, you
may be exactly right, because the Imperial Roman war chariots were made
wide enough to
accommodate the back end of two war horses. Thus now we have the answer
to the original question.
Now the twist of the story:
When we 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 Thiokohl
at their factory in Utah. The engineers who designed these SRBs might
have prefer to make them a little
fatter, but the SRBs had to be shipped by train from the factory to the
launch site. The railroad line from
the factory had to sun 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 is about as wide as two horses'
behinds. So, the major design feature of what is arguably the world's
most advance transportation
system was determined over 2000 years ago by the width of a horse's
rear end.
(24 January 2000,
National Review)
