maf wrote:

How difficult would it be to achieve a Heathrow-Croydon-Gatwick rail
connection ? It would reduce M25 load, wouldn't it ?

Why Croydon?

The Southall to Waste Transfer Station branch virtually connects with
the SR Hounslow loop. A connection there and another (or a reverse) at
Clapham Junction, and you're done.

But I think you need something more direct, which would cost more. As
things are at present, we may not even get all LHR terminals connected
by a single line (i.e. no reversal or change).

Should that be achieved, Heathrow and Luton could be connected via
Uxbridge and Watford, mostly using existing or former lines.

I suspect more new track would be needed for a direct route to Gatwick -
but this would mean the line could be faster. With a 30 minute journey
time, you could destroy the argument for a 3rd runway at LHR by allowing
the two airports to be treated as one for flight connections. I don't
know whether such a railway would be cheaper than the 3rd runway - how
much will 40 Km of CTRL cost?

Of course, if Cliffe were built on the CTRL, connections from half of
Europe could be made as quickly by rail as by air, which would be good
for the planet.

Colin McKenzie