The Space Shuttle

[Peggy McKinney <peggym@mindspring.net>]

The US standard railroad gauge (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 built them in England, and English expatriates
built the US railroads.

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 used for building wagons,
which used that 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 some
of the old, long distance roads in England, because that's the spacing of
the wheel ruts.

So who built those old rutted roads?  The first long distance roads in
Europe (and England) were built by Imperial Rome for their legions.  The
roads have been used ever since.  And the ruts?  Roman war chariots first
made the initial ruts, which everyone else had to match for fear of
destroying their wagon wheels and wagons.  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, 8.5 inches derives from the original
specification for an Imperial Roman war chariot.

Specifications and bureaucracies live forever.  So, the next time you are
handed a specification and wonder which horse's rear came up with it, you
may be exactly right.  Because the Imperial Roman war chariots were made
just wide enough to accommodate the back ends of two war-horses.

And now, the twist to the story...

There's an interesting extension to the story about railroad gauges and
horses' behinds.  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.  Thiokol makes the SRBs at
their factory at 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 line from the
factory had to run through tunnels in the mountains.  The SRBs had to fit
through those tunnels.  The tunnels are 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 advanced
transportation system was determined by the width of a horse's ass!