On Apr 11, 7:03 pm, "Recliner" wrote:
As I recall, Wembley and the two Sudbury stations were four-tracked (two
through lines, two platform lines), but there was only double track
between the stations. Re-instating that arrangement would make it easier
to have more stoppers at those three stations (not something Chiltern
favours), but wouldn't do much for the overall capacity.

Not forgetting Northolt Park, which was built by the LNER and only
ever had double track.

Reinstating the quadruple track at Wembley Stadium would be easy - the
new bridge does not block the through line formation and the provision
of some mainline crossovers to replace the reversing siding would be
simple. Reinstating the quadruple track at the Sudbury stations would
involve the demolition of the platforms - easier at the northern
Sudbury than the southern Sudbury.

Northolt Junction to West Ruislip would be very easy to restore as
well, and in fact really should have been done a while ago - the
Ruislip branch of the Central Line may benefit from an increased
Chiltern stopping pattern at West Ruislip. Aside from the silliness at
Denham and a rather silly bridge design choice south of Beaconsfield,
the remaining GW&GC Joint formation is sufficiently wide in all the
right places for additional trackage.

Personally, the main problem with quadrupling the Marylebone-Neasden
segment is not the part between Marylebone and Lords, it's the part
between Lords and Canfield Place and between Canfield Place and
Neasden South Junction; it would cost at least 500 million GBP just to
acquire the right-of-way and get wayleaves to finish the tunneling and
demolish everything to the west of the six-tracking north of Finchley
Road.

Besides, the segment's not at capacity yet - the signalling at
Marylebone throat will handle a train every three minutes, and I know
that at best there can't be that many trains in the peak on that
double track segment, and even if there were the average speed is high
enough IMO to allow four-aspect signalling between Canfield Place and
Neasden South Junction.