How Specifications Live Forever
 

How Specifications Live Forever
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When you see a space shuttle sitting on the launch pad, there
are two big booster rockets attached to the sides of the main
fuel tank. These are the solid rocket boosters, or SRBs.

The SRBs are made by Morton Thiokol at a factory in Utah.

Originally, the engineers who designed the SRBs wanted to make
them much fatter than they are. Unfortunately, the SRBs had to
be shipped by train from the factory to the launch site in
Florida and the railroad line runs through a tunnel in the
mountains. The SRBs had to be made to fit through that tunnel.

Now, the width of that tunnel is just a little wider than the
U.S. Standard Railroad Gauge (distance between the rails) of 4
feet, 8.5 inches.

That's an exceedingly odd number. Did you ever wonder why that
gauge was used? Because US railroads were designed and built by
English expatriates, and that's the way they built them in
England.

Okay, then why did the English engineers build them like that?

Because the first rail lines of the 19th century were built by
the same craftsmen who built the pre-railroad tramways, and
that's the gauge they used.

I'll bite, why did those craftsmen choose that gauge? Because
they used the same jigs and tools that were previously used for
building wagons, and you guessed it, the wagons used that wheel
spacing.

Now I feel like a fish on a hook! Why did the wagons use that
odd wheel spacing?

Well, if the wagon makers and wheelwrights of the time tried to
use any other spacing, the wheel ruts on some of the old, long
distance roads would break the wagon axles. As a result, the
wheel spacing of the wagons had to match the spacing of the
wheel ruts worn into those ancient European roads.

So who built those ancient 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
destroying their wagons, were first made by Roman war chariots.
And since the chariots were made by Imperial Roman chariot
makers, they were all alike in the matter of wheel spacing.

Well, here we are. We now 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 army war chariot.

Specs and bureaucracies live forever.

That's nice to know, but it still doesn't answer why the
Imperial Roman war chariot designers chose to spec the chariot's
wheel spacing at exactly 4 feet, 8.5 inches.

Are you ready?

Because that was the width needed to accommodate the rear ends
of two Imperial Roman war horses!!!

Well, now you have it. The railroad tunnel through which the
late 20th century space shuttle SRBs must pass was excavated
slightly wider than two 1st century horses' butts.

Consequently, a major design feature of what is arguably the
world's most advanced transportation system was spec'd by the
width of a horse's behind!

So, the next time you are handed a specification and wonder what
horses' rear end came up with it, you may be exactly right.
Now you know what is "behind" it all.

~Author Unknown~

nothing is ever really new, everything is built on some existing technology.

That was very interesting - thanks for the research.

Sorry, I've got to call B.S. on this. I read this story and thought "wait a minute, they redesigned the Space Shuttle because the boosters wouldn't fit through a train tunnel?"

There are lot's of ways to transport oversized item like that, so I did some research and found this:

http://www.snopes.com/history/american/gauge.htm

By the way Snopes.com is the best place to go whenever you get something like this in your e-mail.

well, most of the story is still true when you read that page, it's just details that are different.

But yeah, the boosters were sort of stupid :)

The answer here is amazingly simple.

Sionce when are UNITED STATES railroad sizes the standard at all? Yes it's true about how the US standard has evolved (according to out friend I T MAN, thank you!) But the reality is that the european railway size was definitely influenced by the size of two horses. Interstingly I t Man has been devious in a small way in the information he provided... There are differences of opinion about how wide a horses ares is. The three gauges of railroad mentioned in the article were within 4 inches of width of each other. THEY WERe ALL STILL influenced by the percieved size of the width of a horse cart. For me ... being within 4 or even six inches is enough to say that ASDF's story is true. Thanks for the opportunity to comment

skippy

I should have been more clear, sorry.

I don't pretend to know anything about railroad gauges. They could be based on the alignment of the stars for all I know.

My objection was that like most stories/facts, the internet takes it and details keep getting added to make the story more interesting.

The facts about railroad gauges are interesting but they would be a lot more interesting if we could somehow tie it to the space shuttle or something modern and high tech. But often the person or people that put these "yarns" together often overshoot the mark into ridiculousness as is the case here.

I work in a highly technical field, yet I see this all the time. We do things because that is the way it has always been done. A barrel of oil is 42 gallons. How did this come about? It was the size of the containers used to transport oil when the first oil wells were drilled. Other countries sell oil by the cubic meter rather than the barrel. It also applies when people use their problem solving skills. They use the same methods over and over without really questioning why they are doing something a certain way.

Everything is based on everything else.
And although is might be because of not wanting to change,
it is more likely because of economy of implimentation.

Why recreate the wheel?

But this will be true for ANYTHING
even the most modern and sophisicated standards of measurement are based on an agreement of parties to use that standard.

If aliens came down here, they would be asking WHY are you using that scale?
http://www.remote-control.net/convert/tables/general/

Why a second?
Or a meter?
Or a liter?

For example, why is the second based on it's standards?
You can see in the link above there are four different ways of measuring a second.
But let's say you pick seconds as a portion of minutes,
then it's based on...

"The second is the duration of 9,192,631,770 periods of the radiation corresponding to the transition
between the two hyperfine levels of the ground state of the cesium 133 atom"
http://physics.nist.gov/cuu/Units/current.html

and that's officially derived by only one country's standards
http://www.nist.gov/

BTW, this link is fascinating...look at how many different measurements there are, ways of calculating them
and the implications of each.
Some might save fractions of a penny, that add up to billions in the long run
maybe on a national or global scale.

I love this kind of shit.
How one thing affects another, and so on.

Things that make you go Hmmm.

I remember my old math teacher told us a story of why we most often use X and Y to represent variables. I forget what it was, but it had something to do with printing presses.

hobo, it was probably something about the number of Xs and Ys available. If you have twenty full alphabet sets that you use to print a complete page, you're bound to have about, say, twenty leftover Xs and Ys. Why not put `em to mathematical use?

still makes ya think tho

Pretty old thread, but I thought I'd comment. The supposed fact that the ruts in roads were caused by "Roman war chariots" is, in actuality, not a fact, but instead, bullshit. By the time Rome had become an Imperial power, chariots as war machines had been obsolete for centuries. The only purpose a chariot would have served in Imperial Rome would be ceremonial. A better answer would be that those ruts were caused by wagons, because yes, the ancients had wagons just like less ancient people did, and used them for many things, including trade and supplying armies and so on.