On Sun, Oct 09, 2011 at 12:15:41PM +0100, Robin9 wrote:
Jamie Thompson;123577 Wrote:
Because it provides terminating points where the service can recover
as well as provide isolation from disruptions on the other half.
You may well be right but that's a very negative line of reasoning.
First, how often do they have train break-downs?

Often enough for it to be worth thinking about.

They also get vandalised by feral passengers, or have to wait for ages
in a station because someone is ill, or get delayed by inconsiderate
suicides, or ...
Second, why not have a
contingency plan for that kind split system in the event of a train
break-down but in normal circumstances operate a conventional circular
service?

That might be practical if LO was the only operator using those tracks -
they could just have two timetables and flip between them at will. But
they're not in that lucky position, so the other operators would have to
also have two timetables. Imagine if LO wanted to change the timetable
between Clapham Junction and Willesden Junction. That means that
Southern have to change their timetable on that bit of track, which
means Southern also have to change their timetable both south and north
of it, which means that whoever it is they share track with to the north
also has to change timetables, and so on.

--
David Cantrell | London Perl Mongers Deputy Chief Heretic

The test of the goodness of a thing is its fitness for use. If it
fails on this first test, no amount of ornamentation or finish will
make it any better, it will only make it more expensive and foolish.
-- Frank Pick, lecture to the Design and Industries Assoc, 1916