Originally Posted by
Shaggy Sheep Driver
SRBs. Bollox, of course, as the US rail gauge is same as here; 4' 8.5". But their trains are much bigger. So the chariot wheel / horse's arse theory doesn't follow, as there's no direct relationship between rail gauge and loading gauge.
Yes but the size of the tunnels a train has to pass through is determined by the max train car width which was influenced by the track gauge. So you could say that ultimately the size of Roman Horses rear end was a factor in the diameter of a rocket motor if they wanted to be able to transport it by rail.