On the persistance of standards (was: Fwd: engineering)
- I've just received this one on the Larry Niven mailing list
<larryniven-l@...>. It's nice to see that QWERTY is not the
only example of the persistance of broken specs... Any other ones?
> The U.S. standard railroad gauge (distance between the rails) is 4
> feet, 8.5 inches. That is an exceedingly odd number. Why was that
> gauge used? Because that's the way they built them in England, and
> U.S. railroads were built by English expatriates.
> Why did the English build them that way? Because the first rail
> were built by the same people who built the pre-railroad tramways,
> that's the gauge they used. Why did "they" use that gauge? Because
> the people who built the tramways used the same jigs and tools that
> they used for building wagons, which used that wheel spacing.
> So why did the wagons have that particular odd spacing? Well, if
> 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 in the roads? The
> ruts in the roads, which everyone had to match for fear of destroying
> their wagon wheels, were first formed by Roman war chariots. Since
> the chariots were made for (or by) Imperial Rome, they were all alike
> in the matter of wheel spacing.
> The U.S. standard railroad gauge of 4 feet-8.5 inches derives 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 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 end of two war
> Thus we have the answer to the original question.
> Now for the twist to the story. When we see a space shuttle sitting
> on it's launching pad, there are two booster rockets attached to the
> side of the main fuel tank. These are solid rocket boosters, or
> SRB's. The SRB's are made by Thiokol at their factory in Utah. The
> engineers who designed the SRB's might have preferred to make them a
> bit fatter, but the SRB's 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 tunnel is slightly wider than
> the railroad track, and the railroad track is about as wide as two
> horses' rumps.
> So, a major 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!
> Don't you just love engineering?