In article ,
James wrote:
(Boltar) wrote in message . com...
I was reading a book by Brian Hardy about the tube trains on the Isle
of Wight and he states that the LUL track gauge is 4 foot 8.75 inches
but the BR gauge is 4 ft 8.5 and that this caused issues initially. Is
this a true statement (perhaps he was misinformed?) as it seems
amazing to me and if it is does it cause any operational issues on
shared tracks such as on the Bakerloo and Met?
B2003
Regular 4'8½" gauge track actually varies in gauge between 4'8¼" and
4'8¾" depending on track curvature. If you think about it, this
difference of half an inch between minimum and maximum is actually a
quarter inch on either side - a wholly insignificant amount. If stock
which has wheels ¼" further apart tries to run on such rails, there
are likely to be no problems, although they may end up riding on the
wheel-flanges. As to whether that statement is true, I have no idea.
Official track gauge is normally specified in mm. As I recall, the BR
track gauge was actually changed a few years ago by a few mm. I think it
changed from 1438mm to 1435mm (or maybe the other way around) for
nominally straight track. It was something to do with the slight
variations in the preferred rail head and flange profiles, both of which
tend to change with wear. Gauge widening is only significant on sharply
curved track.
David