Railroads and Rocket Science!

[x568wcn]

Does the statement, "We've always done it that way" ring any bells?

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 warhorses.
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!

[John B]

Mark,

Excellent pictures of 4771 it really is great to see her in action again. Shame about the diesel tagging along, but life is never ever perfect.

When anyone asks "what have the Romans ever done for us?" then I immediately and fondly remember a certain Monty Python dialogue from "The Life of Brian". The Roman's contribution to technology two thousand years ago was really huge.

I heard somewhere in my dim and distant past that the Romans set the limits of the width of a cart (or chariot) in stone (literally) by creating a permanent stonebuilt gauge at all the main entrances to their major cities. Anything too large for the gauge was simply turned away as being too large to be allowed through. See, even back then the beaureaucrats ruled.

Some Roman official, probably with a bad case of piles, sat in a government office in a Roman back street and did us all a huge favour when he confounded everybody with his 4' 8 1/2 inch gauge. Was he toying with us all? Or did that measure actually mean anything?

HMmmm

Here's a bit more info off this website:

http://www.mmdtkw.org/VRomanRoads.html

"What about those road ruts? Many human guides and guidebooks will tell you that they were worn into the stones by Roman war chariots. There has also been a long-standing urban legend supposedly linking the standard gauge of railroad tracks to Roman road ruts and the width of the backsides of Roman war-chariot horse teams. More than 2000 Internet sites carry the legend, but it's all bunkum, as both the archeological and railroad communities know. The professionals also know that, while wear may have deepened and broadened some ruts slightly, they were invariably carved into the roads intentionally and by hand to keep traffic going the way it was planned to go. Ruts were carved into narrow sections or through gates like those in the Forum Transitorium or between the famous stepping stones in Pompeii to prevent side-slipping and to keep the wagons "on track". In tight corners, for example at the corner of the Temple of Julius Caesar, carved ruts were curved to nudge the front wheels of four-wheeled carts around: articulated front axles wouldn't be invented until several hundred years after the fall of the Empire. (The lack of articulated front axles was also the real reason that Roman surveyors aimed for strictly straight roads.) Roman roads in the countryside were "high crowned" for drainage, much higher in the middle than at the curbed edges, and ruts were carved into them to keep heavy wagons from sliding toward the edges and tearing up the curb stones when passing in opposite directions. The distance between ruts was essentially irrelevant since the drover would only have to find a rut with wheels on one side to keep his wagon on track."

[x568wcn]

Thanks for that, it was just a funny email I got last night from a friend.

Yes, it is Great to see 4771 back up and running, although when she was creaping along last night in the quiet turning round at the south end of the station, she had an awful deffening squeak!

[richard]

Sometimes these stories have a life before the Internet, but then the Internet warps them into the implausible. An example is the story about bird strike testing APT. I heard this verbally in the 1980s, and New Scientist even published it during the late 1980s. The original had two Derby-based organisations (British Rail and Rolls Royce), but the Internet brings the FAA (ie. the USA's equivalent of the CAA) into it for some unknown reason!

Written from memory, the version I heard goes something like this...

Early in the 1970s, British Rail were testing their experimental gas turbine APT-E from their Derby r&d works. Designed to tilt into curves, this would allow high speed running without expensive re-routing of the main lines to remove all the curves (which is what the French did for the TGV). Running at such high speeds caused some concern about bird strikes. So one of the engineers called one of his mates at Rolls Royce (Aero Engines) down the road.
"How do you test your engines against bird strikes?"
"We buy a chicken from the supermarket and we put it in this big gun that we have, and fire it at the jet engine. We can lend you the gun if you want."

So picture the situation: There's a high speed length of track, presumably with a suitable bend. Pointing down the track in a horizontal position is a large gun. A few million pounds (a lot of money in the early 1970s) worth of experimental gas turbine locomotive is speeding along the track. The gun fires the chicken, and it hits the front windscreen...
...and it breaks the windscreen
...and it goes straight through the leading cab car
...and it goes straight through the gas turbine power car
...and it exits out the rear of the rear cab car!
In other words, an awful lot of expensive train is wrecked.
The rail engineer calls up Rolls Royce again, "Err..."
The Rolls Royce mate replies, "You did remember to thaw out the chicken?"

Richard

[daveinstoke]

Not all of the early American Rail Roads were 4' 8/1/2". A good number in the south during the Civil war were 5' guage. One notable loco was the Genral on the W&A.R.R . This was changed a few years later to conform with the Standard guage.
Dave.