Kilopascal wrote in USMA 10285:
>The Romans' chariots would have made the first ruts in the roads.Those
>chariots were made by or for Imperial Rome with a wheel spacing of 4ft 8
>1/2 ins simply because this was the most comfortable width in which to
>harness a pair of horses. So the chariot is the origin of railway Standard
>Gauge.
.
I replied:
>>In a French publication I read that George Stephenson in designing his
>>railway wanted a gauge that would be a round number in both feet and inches
>>and also in metric. 4 ft 8.5 in = 1435.1 mm
Kilopascal replied
>For sure, no metric country is going to worry about 0.1 mm. It may be
>expressed as 1435 mm, but in metric countries where centimetres are more
>frequently used, the width is described as 143 cm. I don't know if that 5
>mm makes a difference or not. Or if the 143 cm is a "nominal" number, and
>the actual width is 143.5 cm. Maybe the railroads used in metric countries
>based their railroads on British/Roman designs, but when they have to work
>with millimetres, or centimetres, they are going to tweak the numbers a
>little bit one way or the other to make them user friendly to the person
>measuring in metric. They are not going to care if the BWMA likes it or
>not.
Trains can roll from Inverness to Istanbul. They couldn"t do it if the
British gauge was 1435.1 mm and the continental gauge 1430 mm. European
mechanical engineering uses the millimetre for all dimensions, including
the dimensions of railway locomotives. I assume that the railway gauge is
also expressed in millimetres as 1435.
