The Crossrail branch to Kingston will probably replace the District line
service to Richmond. What should happen to the 6 District trains per hour
that currently serve Richmond?

If they are diverted to Wimbledon (as Crossrail appeared to suggest earlier
this year), it would halve the frequency of District trains to West
Kensington and subsequent stations. On the other hand, with the other
Crossrail branch serving Ealing Broadway, there seems little point in
diverting them all there, which would put more pressure on the section
through Ealing Common where the track is shared with the Piccadilly.

How about sending them to Northfields? There are 4 tracks between Acton
Town and Northfields, so it shouldn't affect the Piccadilly too much. Also,
with the District serving South Ealing, the Piccadilly could omit that stop,
which means the Piccadilly could stop at Turnham Green to connect with
Crossrail without affecting journey times (for the Heathrow trains anyway).
Another advantage is that it doubles the number of trains serving Chiswick
Park, which by then will have 7000 workers at the Chiswick Park office
development.

Or should there be a more radical review of West London tube services
including the Central line?
--
Richard J.
(to e-mail me, swap uk and yon in address)