For those of you that are interested in why the track gauge in the US is 4’81/2", I offer the following link to an interesting article: http://www.straightdope.com/columns/read/2538/was-standard-railroad-gauge-48-determined-by-roman-chariot-ruts
“The Straight Dope” started many years ago in Chicago as a sort-of underground publication, and has now become a rather fascinating collection of tidbits of information.
This has passed on the internet many times over the years. And there are many who have debunked the claim, too. So I’m not sure it is 100% factual or true.
This is an urban legend that has been proven wrong several times over – check Wikipedia, as an example.
https://en.wikipedia.org/wiki/Standard_gauge
and I believe Snopes has also debunked this theory.
Having the gage evolve generally from wagon tracks seems entirely plausible. Standard gage became standard because it was generally deemed adequate and the more it was used, the more attractive it became. It really does not require a specific plot to explain the width of standard gage. The dimension of 56 ½” might seem odd and in need of an explanation, but there is nothing odd about 56”. The extra ½” seem a little quirky, but the explanation that it was added for flange clearance seems entirely plausible.
However, this does get into some bewildering issues as to whether you add the ½” to the track gage or deduct it from the wheel gage. To achieve more flange clearance, they could have made the wheel gage 4’-7 ½”. I guess it depended on whether it was more work to change the wheels or the track.
Track gage is objective because it is measured inside the rail head sides. Whereas wheel gage is a measured between arbitrarily established vertical planes in space.
If you use the search function of this forum and search “gauge” and “chariot” you will find links to several long discussions about this theory we have had over the years.
Basically all of the attempts to analyze the “Roman Chariot” stories do seem to conclude that there is some truth to it in the sense that Stephenson’s “standard” gauge did derive from the most common size axle width for wagons of the type used in the industries that first embraced rail transportation (mining) but that this has more to do with the fact that an axle width of approx. five feet (give or take) was necessary to allow sufficient room for a carthorse to fit between the wagon shafts…
And, a few years back, there was an article in Trains about Hitler’s proposal for a wider gauge–about nine feet, as I recall
As to the additional half inch, could it have been that the actual gauge of the chariot wheels was some particular Roman measure, and after the English measuring system was standardized the gauge was discovered to be 4’ 8 1/2"?
In the big picture, I think that asking for the origin of standard gage is an impossible question to answer. It is like asking for the origin of time.
No one has established that chariots were standardized so this theory is just crap. Chariots would have been entirely hand made over the huge range of the roman empire and there no standards of accurate measure. A society measuring with “spans” and “cubits” and such could not have been able to produce a standardized object like a chariot. So , which chariot would it be?
I have seen this argument for years and years. I have some books published in the 1880’ and 1890’s that tell essentially the same story about Roman chariots, so it has been around a LONG time.
Personally, I contend the “odd” dimension is the result of a redefinition of how to measure gauge. I think that the original gauge was exactly 5 feet. But that was measured from center of rail to center of rail (just like how studs in a wall are measured, or balusters on a railing, or any other sets of parallel thicknesses).
If you take that 5 feet and subtract one half of the width of each rail (or the width of 1 rail) you will find that the answer is pretty close to the “standard” of 4’ 8.5", depending on what width rail MIGHT have been in use when someone realize that the only important measurement is the distance between the rails, not the center to center measurement. If you use the inner edge to inner edge measurement then you can make the actual rail any width you need (for weight support, strength, etc.) and still maintain compatibility with any other track used by the same axle/wheel set.
Only the chicken that crossed the road knew for sure and he didn’t fare well on the return trip. This chicken doesn’t know, but was also told the story about the wheel flange was originally on the other side of the rail with 5’-0" being the outside dimension.
I agree that they would not have begun with standardized the gage of non-track wheeled wagons or chariots. However, if they ran on roads surfaced with laid stone; and if they eventually cut ruts in the stone; then you would have what amounts to a railroad. At that point the rut spacing would amount to a gage. And from then on, you would have to build wagons to match that gage.
Of course, the ruts would have developed according to a variety of wheel spacing, but as time when by, a natural consensus would have developed as to what spacing was the most common. And then the ruts would have tighted up their variation.
And measuring units would not have been a problem because all they had to do is match the ruts. That was the measuring unit.
Standard gauge exists out of chance more than anything
OK the most basic origin to standard gauge is this, George Stephenson first successful locomotive for the Stockton and Darlington was built to match the EXISTING coal mine tramway gauge that the sponsers of the competition owned, and that was in all probability built to match the existing flanged cart wheels that the horse team would pull. That distance was at the whim of who ever the original cart builder for the line was and what standards he employed, but for the most part it had more to do with building to the accepted customs of a road carriage or wagon wide of the time, being enough to comfortably sit 2 side by side, but narrow enough not to be bother on the narrow roads of the time. It could very easily have been anything from 4’6" to 5’. Stephenson simply didn’t want to bother with recreating something that for him worked well with his successful design, so any new orders he received he simply copied the S&D chassis, wheel gauge included and the buyers would be responsible for adjusting their track gauge to match, but given that the majority of his work was building the from-scratch Liverpool & Manchester and other new lines, the builders agreed to accept the product Stephenson was providing. Other later manufacturers simply matched the gauge as that was what already being built and they wanted to get into the game. It wasn’t until Isambard Kingdom Brunel said "wider is better and built the broad gauge Great Western RR did anyone seriously challenge the acceptance of standard gauge.
That’s the most plausable explanation I’ve yet heard, and it makes sense. 4’8" between railheads just made it easier to measure and eventually become known as.
The legend I’ve always heard it that the Roman chariots were drawn by 2 horses and built to the dimensions of two horses standing next to each other. That is why their wheels were about 4 1/2 feet apart. Of course this does not explain small discrepancies and I suppose there is a certain arbitrariness in 4 feet 8 1/2 inches.
That’s true, but the chariots would have had one thing in common- being pulled by a horse. Was there a standard for the width of a horse’s butt?
I think that’s getting into a gray area.
I’ll let you know as soon as she gets home from the store…
[(-D] [(-D] [tup]
[:-,] Now, I have an assignment for anyone who’s so bold and intrepid as to undertake it: Go find a representative example of said horse(s) butts (the actual ones, not the political or management kinds ,etc.), and measure its/ their width(s). Try not to get kicked in the process . . . [:-^] (Sadly, a pony’s kick killed a kid just that way a few days ago in central Pennsylvania.)
Instinct, experience, and judgment are telling me that no single horse butt is anywhere near as wide as 4’-8-1/2", not even in the draft horse class (Clydesdales, Percherons, Belgians, Shires, etc.). But, I also anticipate it is equally unlikely that 2 horses will fit comfortably side by side into the 4’-8-1/2" space when allowing for working clearance, the harness gear, etc. Anybody know for sure ?
First off, Murphy, this is a legend I have heard for many years. But I really cannot vouch for the accuracy of it.
However, I suspect in the Roman army there was a standard for the width of a horse’s butt. When I was in the Army there were standards for height and weight of soldiers. I would think that when they used draft animals the army would have similar standards.
John
4’ 9’’ was the width of cart track ruts in Pompeii when we visited (I measured them) it was not the ruts as much as the distance between the stepping stones across the street, they must have had some standards as to wheel distance but they had to fit between the stepping stones, if anyone has ever travelled on a deep rutted dirt road, you can put one side in the rut and the other out of the rut, otherwise the ruts will get so deep you will bottom out, as long as the Romans were cruising the country they could put there wheels anywhere but to get through a town or village they MUST fit between the stepping stones. so I’m sticking with this premise. check the streets in Pompeii on google maps and it (sort of) makes sense.
Now, if this was ever the standard used to gauge railway tracks- - I’m not sure.