In message , at 19:11:48 on
Wed, 20 Jul 2005, Paul Corfield remarked:

The crime scene is very close to the trailing crossover just south of
Kings Cross hence the closure.

There are no other crossovers between Arnos and Hyde Park Corner.

Why can't they run a "one train on the line" shuttle service on both the
tracks simultaneously? Over strategic sections: eg from Green Park to
Holborn and back. And Kings Cross to Finsbury Park and back.

Or is the reduced capacity that would offer actually worse than running
nothing at all?

The frequency would be so low as to be almost useless - a train every
20-25 mins in each direction on each track at best.

Green Park to Holborn is only four stops. Say 2 minutes each. And 2
minutes to reverse. These are worst-case. That gives you a complete
round trip in 20 minutes, and with two tunnels a 10 minute frequency.

That analysis ignores whether you could deal with the situation at
Arnos Grove as not every train could head south from there so some
people would still have to be placed onto replacement buses as the
trains couldn't carry the likely demand.

I'm not proposing anything changes at Arnos Grove.

You also have the issue of trains from each platform
going in each direction with the platform indicators and station signage
not configured to be able to cope with such an operation.

Have someone at each station operating a sign that says which (of the
two) platform the next train each way is expected. Green Park to Holborn
would need five people.

You would get massive issues at somewhere like Finsbury Park - what
platform would you go to and when for a northbound or southbound train
if both Picc tunnels ran in both directions?

You'd need to use some intelligence to set up a suitable system. Why are
you so defeatist?

quite how match crowds for Arsenal will be managed I dread to think if
the Picc remains out of action for a long while.

You'd probably need to close my system for the duration of football
matches. Yes, I can be defeatist too.

It is far better to get people away from closed sections of line and on
to alternatives that are able to provide a robust level of service.

If the alternate service is that good, why have the original service? (I
detect people asking this question about the Circle Line...)
--
Roland Perry