"Graham Harrison" wrote

I wonder if curtailment at West Ealing is about capacity through the flat
junction? Which makes any use of the line up to the NLL from the GWML an
issue as well. Combine the 2 routes and I suspect you have a complete
no-no so long as they remain flat junctions.

West Ealing will remain a flat junction, though current timetabling makes
the best of it, with up and down Greenford trains passing each other at or
close to the junction. The Crossrail proposals take the spur from Acton
Wells round the back of Acton Main Line station, with a diveunder so that
the down spur joins the down relief without conflicting with the up relief.

Peter