[1662] in Humor
HUMOR (sorta): The Truth About Railroads
daemon@ATHENA.MIT.EDU (Andrew Bennett)
Sun Oct 27 10:47:47 1996
Date: Sun, 27 Oct 1996 10:43:27 -0500
To: humor@MIT.EDU
From: abennett@MIT.EDU (Andrew Bennett)
Date: Thu, 24 Oct 1996 23:49:15 +0000 (GMT)
From: Espacionaute Spiff domine! <MATOSSIAN@aries.colorado.edu>
Subject: The ugly end of another great Urban Legend. (long, but interesting)
Date: Thu, 24 Oct 1996 19:05:01 -0400 (EDT)
From: Keith Bostic <bostic@bsdi.com>
Forwarded-by: Steve Dekorte <dekorte@suite.suite.com>
[One version of the original posting is appended, it's a discussion
of how the US standard railroad guage is derived from the width of
the Roman standard war horse behind.]
Dan please forward this response back to everybody who got the original
posting, because this particular bit of misinformation is just butt-ugly
wrong.
I worked as a railroad engineering historian once upon a time, so
in this rare instance I actually know what I'm talking about. This is a
classic example of where a nice puffy argument gets in the inconvenient
way of the real facts, which should be interesting to an engineer. There
were actually many, many rail gauge specifications use in the early days.
There were several dozen early railroading enterprises that started from
different operating premises (such as different power ratios, gearing
principles, and so forth) which tended to affect the powertrain. Obviously
some of these ended up being more practical working solutions than others.
Quality of rails and the friction generated, grade, gauge, and the
cost of building a bed (directly affecting gauge) were all major factors
in the "alpha" phase of railroading.
For the first forty years of major railroad activity, there were
divergent trends in the gauge use. These were more stark between the US
and Europe, but even within the US railroads tended to be built at
different gauges depending on the purpose and entity building them (the
thing about English railroad engineers is just plain false, btw). For
example, "trunk" or feeder lines, railroads serving mines in hilly places,
and similar specialty applications -- which were originally much more
economically viable than long-distance, high-capacity service-tended to
be narrower gauges because of grade, and therefore powertrain,
constraints. Different vendors of equipment originally supplied only a
few railroads (of which there were tens of thousands by the 1880s), so
for a short while interoperability wasn't a big problem. (Is this
beginning to sound familiar?)
However, economies of scale kick in after a while. The obvious ones
were vendors supplying parts for railroads; standardization helps mass
production and therefore larger sales. Many railroads ran their own shops,
but couldn't always get the capital up to build equipment for what was
essentially a custom application, if you will, while trying to make money
operating an enterprise. They essentially passed a point when doing it in
-- shop didn't make as much economic sense. The number of things for which
this applied multiplied over the years, but rails, carbeds, and trucks --
hence gauges -- were the most important early components. Then the major
problem, though, (no application to Microsoft implied here, but you may
take your lessons from history where you want) was interoperability.
Railroads, in attempting to build more efficient networks (often prceeded
by ugly business tactics in which small competitors were forced out of
business after initially forming operational alliances with them, but I
digress), found that the 19th century-equivalent of the gateway -- the
transfer point where you had to shift freight from one gauge to another
-- meant that traffic was slowed. If you could work out both a standard
gauge for cars to interoperate between different railroads -- and, very
very important at the time -- a business model that would allow you to
ship freight from one railroad line to another without having to take the
freight out of the car owned by Railroad X and put it into a car owned by
Railroad Y -- you can then have an actual network as opposed to a
conglomeration of vaguely interconnected subsystems. Hence standard gauge
emerged as a clear concept, but one with some evolution underneath it.
Incidentally, there were some pretty freaky interim solutions tried
that kind of reek of the gateway concept -- cars that had two sets of
wheel trucks, cars with variable length axles that would expand or
contract when changing gauges, and even the 19th-century equivalent of
container cars that could be fit inside other containers. As you can
guess, none of these proved practical at the time.
There was a period of settling out in which gauges got adopted as a
result, after which there were three major standard gauges in use -- the
current 'standard' gauge, and two narrower gauges.
So, how did this particular gauge come about? Our friend's horseshit
tale of it dating back to Roman chariot widths may have occasional bits
of fact, but the real answer is based on _engineering needs of the day_.
The standard gauge was the widest original width you could reliably make
an iron axle (pre-bessemerized steel days) that would support the
then-weight of locomotives. Basic structural engineering which I won't go
into in detail but which should be easy to calculate; there's a basic
tradeoff between thickness, length, and number of axles in a traintruck
that's related to weight bearing and stress. Of the several gauges that
became more widely used in the 1840s and 1850s, what eventually became
standard gauge was simply the one that was in the working tolerance ranges
that was most widely used at the time.
Note also that later engineering advances -- such as reliable steel
production, better power sources (diesel, electric), better car-building
methods, etc. -- could not later change the gauge, because a critical mass
in the mileage of track that interoperated and generated vast gobs of
revenue had been reached and it would be too expensive to go back and
rebuild the rail network for what were secondary, albeit superficially
technical superior, reasons that may have supported a different gauge at
that point. One very salient footnote to this is the final act in the
process of standardization. You see, some companies claimed they built
things to standard gauge, but there continued to be small differences.
Occasionally these were just accidents, occasionally they were deliberate
strategies used by a railroad (or sometimes even suppliers) in order to
make a competitor unviable. For instance, if you wanted to kill off a
little trunk line that was shipping grain from a grain elevator in Podunk,
Iowa to your main line of ReallyBig Railroad corporation, you'd change
the coupler that held freight cars together or the switching device that
sidetracked cars, making sure your couplers worked with both systems. The
trunk line would have to refit its cars to your spec or lose the business.
Quite frequently, they lost the business because they wouldn't change, or
spent so much money keeping up with the demands of the bigger lines that
they had to sell the small lines out. Whereupon, of course, standard
parts were reintroduced for the convenience of the bigger lines 8-).
There were actually several thousand important devices, ranging from
switching systems to bolts and nuts, that fell into this category. In the
case of standard gauge, there continued to be residual small fights about
what the exact width of the distance between rails, the required width of
the rails, whether rails were capped or not, whether they were spiked or
welded, what the appropriate tie ratio per unit of rail was, and so forth
well into the end of the 19th century. (I will spare you the history of
the financial machinations that nearly bankrupted the entire country that
were a parallel to the problems of getting interoperation on a technical
level). The point is that the width between the rails was one factor
among many that dealt with quality of the final product.
And guess what, boys and girls? It wasn't until the Interstate
Commerce Commission was formed in 1887 that there emerged final order in
this chaos of competing engineering standards. The ICC, for all you read
about it in history books as being a price controller for tarifs, also
was an umpire for allowing standardization of various bits of railroad
technology as they became mature. The ICC actually did a good job of
staying out of the actual engineering of things, only getting involved
(at least for the first 50 years or so of its existence) with technical
standards that actually affected the abilities of railroads to
interoperate. While I wouldn't propose the parallel situation of, say,
making the IETF a government agency (ugh), having a third party that was
not commercially motivated was what actually made the gauge standard; I
believe from memory the original order for standard gauge was in 1889.
So the "spec" in this case emerged from engineering practice, and it
only became generally useful when the monopolistic players were forced to
conform to it (the little guys never have a choice in these matters).
And that is the real story.
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Matt Wall
wall@cmu.edu
Carnegie Mellon University
<http://www.contrib.andrew.cmu.edu/~wall
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
US Standard Railroad Gauge
or
How MilSpecs Live Forever
--------------------------
The US standard railroad gauge (distance between the rails) is 4 ft 8 1/2
in (1.44m). That's an exceedingly 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 ex patriots.
Why did the English build 'em 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 as they used for building wagons,
which used that wheel spacing.
OK! Why did the wagons use that wheel spacing? Well, if they tried to
use any other spacing the wagons would break on some of the old, long
distance roads, because that's the spacing of the ruts.
So who built these old rutted roads? The first long distance roads in
Europe were built by Imperial Rome for the benefit of their legions. The
roads have been used ever since.
And the ruts? The initial ruts, which everyone else had to match for fear
of breaking their wagons, were first made by Roman war chariots. Since
the chariots were made by or for Imperial Rome they were all alike in the
matter of wheel spacing (ruts again).
Thus we have the answer to the original question.
The United States standard railroad gauge of 4 ft 8 1/2 in derives from
the original military specification (MilSpec) for an Imperial Roman army
war chariot. MisSpecs (and bureaucracies) live forever!
=======================================================================
Andrew Bennett MIT Department Ocean Engineering
MIT Room 5-424 77 Massachusetts Ave.
Cambridge, MA 02139 <Standard Disclaimers Apply> Phone: (617) 253-7950
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