Just Follow the Specs
Received by Email one day, source unknown
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 the US railroads were built by English expatriates. Why did the English people 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 use that odd wheel spacing? Well, if they tried to use any other spacing the wagons would break on some of the old, long distance roads, because that's the spacing of the old wheel ruts. So who built these old rutted roads? The first long distance roads inEurope 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. Since the chariots were made for or by Imperial Rome they were all alike in the matter of wheel spacing. Thus, we have the answer to the original questions. The United State standard railroad gauge of 4 feet, 8.5 inches derives from the original specification (Military Spec) for an Imperial Roman army war chariot. MilSpecs 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 chariots were made to be just wide enough to accommodate the back-ends of two war horses.
A footnote to the article:
When Napoleon invaded Russia the difference in wagon ruts slowed him down keeping him from reaching Moscow before winter set in and froze his army. When Germany invaded during WWII the difference in railroad gauge slowed down the German logistics. They had planned on the difference in rail size and had sets of wheels for the wider Russian gauge but the fact that the Russian engines were wider meant that they carried more fuel and water. This meant that the depots were spaced far enough apart that the German engines couldn't make it from one depot to the next with a full load of cars without running out of fuel or water part way.