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 spec and told we have always done it that way and wonder what horse’s ass came up with that, 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…

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 in 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 bout 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.



    • SNOPES is not the end all be all of FACT… In “fact” SNOPES often assesses Truth/False based upon SUBJECTIVE OPINION rather than actual OBJECTIVE FACT, as is the case HERE..

  1. A very well written and funny take on an old story. That is more than can be said for the po-faced article in the link, which seemed to be as much at pains for some reason to downplay the link of the current American standard gauge to the Old World as to “correct” the story. In the end it doesn’t correct the story very much, because the heritage is there for all to see, not perhaps in a direct “A lead to B lead to C” way but in the general thrust of history. Anyway this is getting a little po-faced, but I’d give this story at least 4 out of 5 and the Stopes article a -1 for party pooping.

  2. The detail may be wrong but there is certainly truth in it. Although the Romans never used war chariots, they certainly used lots of supply wagons, which had the axles spaced at around the same as in the early age of steam, or even today (war chariots in Roman times were used most famously by the British tribes under Queen Boudicca, who the legions slaughtered in the Battle of Watling Street). Btw, a Roman Legionary baggage train was called (in Latin) an “impedimenta”. From which we get the English word impediment.

    • Actually the article is correct (mostly) and your paper does in no way say anything about anything that causes this article to be incorrect (except the chariot thing of course, but that is rather unimportant since in reality it was nearly the same thing; Roman baggage trains as mentioned by other commenters).

      The fact is your article mostly explains the same things as this text just in a lot more roundabout matter making it unnecessarily hard to read, which for some reason you seem to be proud of. The paper is actually a piece of crap since on the main topic of the railroad gauge your article only states that the current gauge was chosen because it was most prevalent at the time after the civil war, which completely begs the question of the underlying reasoning for WHY it was most prevalent, which is the root cause that that this article attempts to answer.

      You really should think things through more thoroughly before attempting to look smart and failing.