Standard Gauge??

[blueriver]

Hi,
I'm wondering; How did the Standard Gauge become 4'-8 1/2"? What is the history behind it? Why not 4'-6" or 5'-0" or even 4'-8" for that matter? That 1/2" seems silly when you are dealing with the size of the equipment on the rails. Will someone enlighten me please.

Thanks
blueriver

[Anonymous]

To the best of my knowledge, this is left over from the earliest days of the horse-powered mine railways over here - the first steam locos were built for these, and when the lines expanded (geographically) they kept the gauge. There was an attempt to set it wider (I K Brunel's "Broad Gauge" - 7' 0 1/4) but it didn't last long - the lack of compatibility resulted in massive problems at junctions so the Broad Gauge GWR lines were eventually all relaid to 4' 8 1/2.

Why it is so precise I don't know - I've always been puzzled by one narrow gauge line near me, while a large number of other railways in the area were built to 2ft gauge (North Wales slate hauling lines - many now open for tourists), the Corris railway was built to 1ft 11 1/2 - why they didn't just go for 2ft like everyone else around them has puzzled me for years!

[twhite]

Evidently 4'8-1/2" was the distance between wheels on wagons and chariots during the Roman Empire, and the English used that distance as a measurement when laying the first collery tracks in Britain. At least that's what I've heard. Evidently Julius Caesar's chariots left some permanent tracks on stone roadways in Britain, or something. Actually, some of the early railroads had different gauges--up to seven feet for British 'Broad-Gauge', and even the Erie Railroad in America was originally laid to six feet between rails. 4'8-1/2 is standard for America and most of Europe, though Spain and Russia are still holdouts at 5'.
Tom

[cefinkjr]

Tom:

The story of Roman chariots being standard gauge has been around for a long time -- might even be true. [:)]

I heard another story recently that puts the origin of standard gauge as even a bit earlier than Roman chariots. Seems that the width of a Roman chariot was dictated by the width of their motive power and 4' 8 1/2" (in English measurement) was a convenient width to use for the very common 2 HP chariot (chariot horses being smaller and narrower then). All chariots came to be made to the same gauge so they could follow in the same ruts without tilting heavily to one side or the other on unpaved roads.

This is so logical and so like Roman engineering that it might just be true.[:D][:D]

Chuck

[IRONROOSTER]

Here's a somewhat longer discussion of the chariot theory
http://www.spikesys.com/Trains/st_gauge.html

The other theory I have heard is that the gauge was originally 5 feet with the flanges on the outside. The gauge was measured to the outside of the rail. When that didn't work and the flanges were moved to the inside, the gauge was changed to 4' 8 1/2' so that the rail would not have to be relayed.

Who knows. Personally I like the chariot theory better.

Enjoy
Paul

[howmus]

I have heard the Roman connection several times. It probably has some basis in fact. The English supposedly adopted the same measurement because of the ruts in the roads left by the Roman Chariots. They brought the same tools used to build wagons to America during colonial times. Early tramways (horse drawn railroads) used the same basic equipment to make their equipment because it was handy and already available. The width is predicated upon the width of the rear ends of the horses pulling the chariots. Sooooooo! Next time you wonder what horses rear end came up with something..... You might be right!!!! LOL

[ben10ben]

What I have always heard regarding the half inch was that track was originally gauged to 4' 8". The half inch was added at a later date as a means of reducing flange friction between the rails and the tires.