In message , at 12:02:07 on Fri,
29 Sep 2006, Graham Murray remarked:
Or even put in a chord, if there is not one already, to allow trains
from the West to access Heathrow directly.

aiui the tunnels and stations at Heathrow belong to BAA (and were
constructed at their expense). They don't have any trains that could use
a new chord such as you describe, so there would have to be some extra
co-operation between BAA, NR, and whoever will run these new trains.

I wonder if diesels are permitted, in any event. If not the project will
be moot until there's electrification towards the west, as far as
wherever these trains will come from.
--
Roland Perry