In message , Yokel
wrote:
Anywhere on the railway network that you have a triangle of lines, this
issue has to be overcome.

Or loops, and they can be big ones.

It is Down from both St.Pancras and King's Cross heading north, so if
you go between them via Grantham and Nottingham you have to change
direction; in this case it's at Netherfield Junction, just east of the
latter.

Or sometimes there's no obvious reason. The erstwhile Oxford to
Cambridge line is currently Down both ways from Bletchley (presumably
because of its LNWR heritage). That means a train from Oxford to Bedford
(if the gaps were repaired) is Down for the first mile or so, then Up to
the middle of Bletchley flyover, then Down again. (It's also Down from
Aylesbury to Claydon L&NE Junction.)

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Clive D.W. Feather | Home:
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