On Sep 14, 5:40 pm, "John Rowland"
wrote:
chunky munky wrote:

The Current Off Peak Piccadilly line service is
every 20 mins Cockfosters - Uxbridge
every 20 mins Cockfosters - Rayners Lane
every 5 mins Cockfosters - Heathrow
every 20 mins Arnos Grove - Northfields

In the peak the Northfields trains, more or less run to Ruislip and
there is a 5 minute service, both to Heathrow and Rayner's Lane.

The new timetable starting in January ("Shadow Running" when T5
trains start running, empty from/to T123) I understand will be every
10 minutes to T4 and every 10 minutes to T5, via T123. I think that
the T4 trains will then reverse at Arnos Grove, with no more
Northfield "locals". There shouldnt be a change to the Rayners
Branch.

That's a drop from 21tph to 18tph through the pipe, and from 18tph to 12tph
at Cockfosters. I suspect you've got something wrong there.

Something's got to go round at Arnos instead! It might well be the
20min either Uxbridge or Rayners Service. Either way the service is
going to become much more complicated than at present! And probably
more un-reliable if you are after a certain destination.