This marvelous informal article Ana copied about how ancient chariot
wheel widths eventually became transformed into modern US, British
and Canadian railroad track widths is a perfect illustration of a
"root cause analysis," a process followed in many industries to try
to understand and find solutions for accidents, waste, and other
undesirable things. I recently took a class series at work in this,
which spurred me to stir up that little discussion about causality
the other week. It had got me wondering how causality figures into
There are actually a number of different root cause analysis
methods. The one Boeing uses, the "Apollo" method, developed by
Texas engineer and accident investigator Dean Gano in the 1980's, has
an interesting philosophical premise: we live in an infinite
continuum of causes. There is no single "root" cause, just causes
that are more available to influence or eliminate. According to
Gano, effects always have at least two causes: some causal condition,
and some causal action. The effect combustion typically has two
causal conditions, oxygen and fuel, and an action, ignition. The
solution to preventing a fire might be to remove the possibility of
ignition. Removing the fuel and perhaps the oxygen could also be
solutions. A causal analysis of a fire might include asking why the
fuel was there (flammable liquid fell from a truck) why did it fall
(not secured properly) why wasn't it secured properly (latch was
broken) why was the latch broken (maintenance didn't have the
replacement part) - and so forth and so on.
An especially notable aspect of this causal analysis approach is the
way it sharply distinguishes itself from storytelling. As Gano
explains it, storytelling begins at some point in the past and works
its way to the present. Causal analysis begins in the present and
works its way to the past. Stories or narratives are linear. Causal
analyses are branched, not linear. In a causal analysis, every
effect branches into multiple causes. In the narrative, beginning at
some point in the past, this happened, and then that happened, and
then the next thing happened, moving in a linear direction toward the
present. In causal analysis, beginning in the present, this
happened, which was caused by that and that happening, which was
caused by this, that and the other thing happening, moving in an
ever-branching pattern toward the past. A large part of the "Apollo"
method (this term was chosen because it had both a space age and an
ancient ring to it) consists in teaching ways to facilitate a group
to develop a causal analysis chart that lines up the causes and
effects logically while also keeping track of the complex
branching. The point is to (1) identify the upstream causes that can
change or eliminate the undesirable downstream effects, and thereby
(2) choose/suggest solutions that management will like (cost, ease of
implementation, etc.). Other features of this method include an
emphasis on avoiding blaming, stopping asking why too soon, getting
evidence for all causal actions and causal conditions, and thinking
in terms of events, not categories. Gano calls this a "new way of
thinking" and it does break through numerous paradigms that reinforce
business as usual. Philosophically, it applies a number of materialist ideas.
The analysis of the origins of the standard 4 foot 8-1/2 inch US
railroad gauge Ana copied for us (do visit the site as Ana and Mike
suggest) proceeds not as a story, but as a causal analysis. It keeps
asking "why" and "what caused that to happen?" and proceeds farther
and farther back into British and then Roman past. The process used
was from the present toward the past. Perfect example of an "Apollo"
PS On the site Ana provided, what did the Canadian National Railroad
system engineer Worth mean by "parallel evolution" when he said:
"None of this is to suggest that messrs. Trevithick, Stephenson,
etc., used design manuals from the Sumerian and Akkadian empires in
deciding upon the 4'-8 1/2" gauge. It only illustrates the principle
of parallel evolution, i.e., that 'everything that rises must converge'.
At 09:22 PM 7/15/2006 -0400, you wrote:
>This is very amusing, but after you have read and enjoyed this, try
>Begin forwarded message:
>>*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?
>>*Imperial Rome built the first long distance roads in Europe (and England )
>>for their legions. ??The roads have been used ever since.
>>And the ruts in the roads?
>>*Roman war chariots formed the initial ruts, which everyone else
>>had to match for fear of
>>destroying their wagon wheels. Since the chariots were made for
>>Imperial Rome , they
>>were all alike in the matter of wheel spacing.
>>The United States standard railroad gauge of 4 feet, 8.5 inches is
>>derived from the
>>original specifications for an Imperial Roman war chariot. 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 army*
>>*chariots were made just wide enough to accommodate the back ends
>>of two war horses!*
>>Now, the twist to the story
>>*When you 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 at Utah . The
>>engineers who designed the ?SRBs would 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 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, and the
>>railroad track, as you now know, is about as wide as two horses' behinds.
>>*So, a major Space Shuttle design feature of what is arguably the
>>world's most advanced transportation system was determined over two
>>thousand years ago by the width of a horse's ass.** And you thought
>>being a horse's ass wasn't important!*
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