Space Shuttle Design

[diane]

ENJOY THIS HISTORICAL INFORMATION

Railroads

Does  the statement, "We've always done it that way" ring any bells? ...read to the  end...it was a new one for me.

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 war chariots were made just wide enough to accommodate the back  ends of two war horses.

Now the twist to the  story (remember the title of this bit of work?)...

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!    

[grillbill]

When they first started laying the railways in England they had all sorts of strange guages and some were a lot bigger and roomier than others. Then when they standardised it they all went for the more common guage which was based on the Roman chariots. Shame really.  

[dorbel]

There is a little more to it than one might expect. The GWR gauge of 7 feet was certainly superior in terms of comfort of ride, but as the distance between the rails increases the sharpness of curve that can be accomodated decreases. The standard gauge is a very good compromise.

[grillbill]

They should have made it straighter then. Or they could have put wheels on that move independently of the carriage and follow the track (even my old train set can so that). Now, whenever I have the displeasure of travelling with FGW or Scotrail there's barely space for anything.  

[jonesyjt]

Actually Diane, as all of that seems true, there was an advanced solid rocket motor ASRM to replace the currently used Solid Rocket Boosters SRB's.  This motor was to come in 3 segments instead of 4, and each would be about 12 inches larger in diameter.  All this was to give the Space Shuttle more payload capacity.