On Sat, 24 Jan 2015 13:02:31 +0000, Roland Perry
wrote:

In message
-septemb
er.org, at 12:45:24 on Sat, 24 Jan 2015, Recliner
remarked:
given that Crossrail will run thru three different signalling systems,
integrate into the timetables of two franchises, and mix with local
and freight traffic, one can see it will present an operating
challenge.

Three franchises if you count HEx.

True, though the only tracks they'll share are in Heathrow itself, as
Crossrail will use the GW relief lines and HEx is on the mains.

My impression was that they wouldn't be doing much (if any) track
sharing with Greater Anglia between Stratford and Shenfield.

Yes, I think you're right.