"Clive D. W. Feather" <clive@on-the-train.> wrote in message
news:zbhweDqX4IgIFwcF@romana.davros.org...
> In article
> <8081db85-a836-43ca-afc5-a584d9640671@k30g2000hse..com>,
> rob499@m writes
>>What nobody has pointed out yet is that when a main line is built as a
>>2-track railway and then widened to a 4-track (as happened on the
>>Great Western, for example), pairing by use is much easier than
>>pairing by direction.
>
> Actually I've already pointed out that it depends on whether you widen on
> one side or on both.
And it's a reasonable assumption that widening on one side is less
disruptive to the existing traffic, and therefore cheaper. Not that that's
an argument for doing it, of course. It's no co-incidence that the LSW and
GN routes operate much more effectively in 4-track mode than, say, the GW or
LNW.
Regards
Jonathan