A tenuous (?) connection between several recent postings about
railways, standards, and space shots. And, to keep
it relevant,
even the earliest railway engineers
were known to have used PICs
........ and shovels
------------
The US standard railroad gauge (distance between the rails) is
4 feet 8.5 inches. That's an odd number. Why is that gauge used?
Because
that's the way they built them in England, and the US
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 tramway
used the same jigs and
tools that they used for building wagons,
which used that wheel
spacing.
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
was 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 ?
The initial ruts, which
everyone else had to match for fear of destroying
their wagon
wheels and 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.
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.
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
Thiokol at their 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
line from the factory had to run through a tunnel in the
mountains. The SRBs
had to fit through that tunnel. The tunnel is
slightly wider than the
railroad track. So, the major design feature
of what is arguably the world's
most advanced transportation system
was essentially determined by whoever built the Roman
legions'
chariots.
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
war chariots
were made just wide enough to accommodate the back
ends of two war
horses.