Railroad gauges and horses' behinds (fwd)

James A. Landau JJJRLandau at AOL.COM
Mon Mar 19 01:33:50 UTC 2001

In a message dated 03/16/2001 2:06:41 PM Eastern Standard Time,
rtroike at U.ARIZONA.EDU quoted (inter alia):

>    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 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
>     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?
>     Imperial Rome built the first long distance roads in Europe (and
>     England) for their legions. The roads have been used ever since.
>     The United States standard railroad gauge of 4 feet, 8.5 inches is
>     derived 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 what horses ass came up with it, you
>     may be exactly right.  This is because  the Imperial Roman war chariots
>     were made just wide enough to accommodate the back ends of two
>     war-horses.
>     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 happens
>     run 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, a major
>     design feature of  what  is arguably the  world's most advanced
>     transportation system was determined  over two  thousand years ago by
>     width of a horse's ass.

The reason standard gauge in the United States is 4 feet 8.5 inches is that
Abraham Lincoln (who was an old railroad attorney) had to decide on the gauge
for the Union Pacific Railroad, which was to link the West Coast to the rest
of the country.  At the time there were several different gauges being used
in the US, including 4 foot 9, 5 foot, and 6 foot.  Lincoln decided on 4 foot
8.5 inches because it was then the most common.  A pity, he should have
chosen 6 foot ("Erie gauge" because it was used by the Erie Railroad) which
would have eased the difficult balancing act a railroad train has when it is
wider than its track gauge.

Why 4 foot 8.5 inches?   The story that seems to me most plausible is that
some early builder of mining railroads had to run his track through a doorway
that was five feet wide, and his rails were 2 inches thick.  That meant a
gauge of 4 foot 8 inches.  However, he found that his rolling stock was
having too tight a fit, so he widen the gauge half an inch (easier than
rebuilding his rolling stock).

I have been told that the Russian five foot gauge is due to an early order
for locomotives from some US builder who happened to like 5 foot gauge.


The story about the boosters and the tunnel has nothing whatsoever to do with
track gauge, but rather "loading gauge" which is the allowable width and
height of a railroad car.  The largest loading gauge in the world is in
Russia (are you surprised?).  It is interesting that when the Soviet Union
starting building diesel locomotives, they copied an American design (the
RS-1 from American Locomotive Company) but they took advantage of their
larger loading gauge to put a taller roof on the cab.

The United States, Canada, Mexico, and Cuba use the "North American Loading
Gauge" which is larger than any other loading gauge except Russia's.  Why
does Cuba use it?  Because the first railroads in Cuba were built by the same
Canadians who earlier built the Canadian Pacific.  Useful, too, since until
Castro rolling stock was transferred between Cuba and Florida by ship.

The original quote states incorrectly that "The tunnel is slightly wider than
the railroad track".  This, and the subsequent risque comment, are incorrect.
 The loading gauge is wide enough for a passenger car to contain two
two-abreast seats with an aisle between them, which is a good deal more than
4 feet 8.5 inches.

Did the Romans use war chariots?  I thought they used mostly Legionary
infantry and some mounted horse.

                    - Jim Landau

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