In any case,
not a nice clean number in either system (143.5 cm)--
although the Russians and Finns use something that is very close to 5
ft.
I think that the British also experimented with 7' once upon a time.
Well, God's Wonderful Railway (aka the Great Way Round) used borad gauge
for a time, and it was arounf 7' I am not the person to know if it was
exactly 7', though.
-tony