"Robin9" wrote in message
...

Incidentally if splitting the service to provide a safety margin is so
advantageous, why not use the idea to incorporate some of the extensions
to the London Overground that have been suggested in this forum over the
past few months. For example, instead of the current Richmond to
Stratford service, why not Richmond to Caledonian Road and Queens Park
to Stratford?

Because Richmond to Stratford is already about as straightforward as it
gets, an end to end route for LO into dedicated terminal platforms, even
though it is overlaid with freight movements.

What you are suggesting would add at least three more areas of complexity;
reversing at Caledonian Rd, additional flat crossing conflicting movements
at Camden Rd West Jn, and reversing at Queens Park, where the existing
service already has to be pathed with the Bakerloo line.

Also, you'd presumably expect to have space for more trains along the
section where the two routes overlap - if not you'd have to reduce the
number of departures from Richmond and Stratford...

Paul S

On Oct 9, 12:15*pm, Robin9 wrote:
You may well be right but that's a very negative line of reasoning.
First, how often do they have train break-downs? 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?

A break down is the most obvious case. The far more common one is
gradual accumulation of delay seconds. A held door, a delay of a Met
service beyond Baker St., A District service running late due to a
passenger alarm...all these things can cause the Circle service to
start running late. Without a terminus...it can only get later and
later, and eventually, the lateness builds up and it starts missing
it's path at junctions and controller intervention is needed to fix
things by taking something out of service, probably at Edgware Road as
it's one of the few locations with the correct trackwork.

It's why I'd like to have the former widened lines as part of the SSL
system. Assuming connections made at Farringdon and Moorgate, give the
centre roads over to the Circles, and run the Mets on the outer lines.
Circles could be scheduled to simply bypass delayed units on these
sections. A similar arrangement could be instituted between Gloucester
Road and South Kensington (where it already kinda does, as the
westbound District and Circle are kept separate). Knock though the
bays at Mansion House and Tower Hill and you have another couple of
locations where you can do this as well. Maybe Aldgate too

"Jamie Thompson" wrote in message
...

It's why I'd like to have the former widened lines as part of the SSL
system. Assuming connections made at Farringdon and Moorgate, give the
centre roads over to the Circles, and run the Mets on the outer lines.

It is known that connections can't be made at Moorgate without spending 100s
of millions though - the alterations to have a junction east of the
platforms involve adjacent building foundations - and there is basically no
way a business case would ever stand up.

Circles could be scheduled to simply bypass delayed units on these
sections. A similar arrangement could be instituted between Gloucester
Road and South Kensington (where it already kinda does, as the
westbound District and Circle are kept separate). Knock though the
bays at Mansion House and Tower Hill and you have another couple of
locations where you can do this as well. Maybe Aldgate too

By the time the SSR resignalling is complete in 2018, it is not intended to
have any Mansion House terminators, and the bay platform there is to be
taken over by the through route. However there is a plan to make Tower
Hill's central platform accessible from both directions...

Paul S

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

On Fri, Oct 07, 2011 at 12:51:35PM +0100, David Cantrell wrote:
On Thu, Oct 06, 2011 at 04:57:58PM +0100, Paul Scott wrote:
I'd expect that resurfacing of the whole
platform, and reopening the second set of stairs, will be done once
the work actually starts at the station....
One has to wonder why that wasn't done at the same time as they laid
the extra track just north of the platform. Presumably platform 2 will
have to be closed *again* while those works are going on.

Well, it looks like that work started over the weekend, with trains now
stopping further along the platform where there are some new buffers
installed. The southern half of the platform is now hidden behind
wooden hoardings.

Platform 2 is still open, but because of the hoardings and the pointless
unused buildings that are still standing in the middle of it, is even
narrower than normal and even more crowded when southbound trains empty.

No evidence of re-surfacing the northern end of the platform.

--
David Cantrell | Bourgeois reactionary pig

Eye have a spelling chequer / It came with my pea sea
It planely marques four my revue / Miss Steaks eye kin knot sea.
Eye strike a quay and type a word / And weight for it to say
Weather eye am wrong oar write / It shows me strait a weigh.

On Oct 10, 10:04*am, "Paul Scott"
wrote:
It is known that connections can't be made at Moorgate without spending 100s
of millions though - the alterations to have a junction east of the
platforms involve adjacent building foundations - and there is basically no
way a business case would ever stand up.

I know...but it's still unfortunate. Interestingly, these foundations
don't seem to be a problem for Crossrail...

It's such a shame...as once you get past those foundations you have a
clear run for four tracks across Finsbury Circus to Liverpool St. East
of there...well. I don't think you'll even be able to widen the former
bay for an extra platform, let alone have a junction east of
there...but I guess if you could redevelop the building sitting over
where that needs to happen it could...

By the time the SSR resignalling is complete in 2018, it is not intended to
have any Mansion House terminators, and the bay platform there is to be
taken over by the through route. * However there is a plan to make Tower
Hill's central platform accessible from both directions...

Quite. However, rather than projecting Mansion House's centre bay to
the eastbound line and severing the western connection to the
westbound, how about projecting it to the westbound and retaining
it's western layout (turning it into a westbound loop). Knock through
the disused northern bay and connect it at both ends to the eastbound
line, and hey presto, you have a pair of island platforms where
services can be reformed. Having a shared bidirectional centre loop is
easier and cheaper...but not as flexible by a long shot.

....I suspect a shared centre road is the plan at Tower Hill, but
likewise, I think a pair of loops (a-la the old Whitechapel - I really
wish they'd found a solution that kept the centre roads) would be
*much* more useful.

On Oct 7, 7:41*pm, Robin9 wrote:
David Cantrell;123554 Wrote:



There will be no Overground services going *through* Clapham
Junction, and no services starting at Clapham Junction, going all the
way round the circle, and ending at Clapham Junction.

Does anyone know why not? I distinctly remember hearing Ken Livingstone
in his day saying that the London Overground would provide London for
the first time ever with a circular service through the suburbs. He
quite obviously saw the London Overground as a kind of Outer Circle
Line.

Currently we have services from New Cross etc terminating at Highbury
And Islington while other services from Stratford go through Highbury
And Islington to Clapham Junction. Why is this arrangement better than a
straightforward Outer Circle system?

--
Robin9

Practicality and customer demand. Joining the SLL and WLL would mean
missing Clapham Junction, a major traffic objective. Westwards from
Highbury to join ELL and NLL is possible (current track arrangements
notwithstanding), but would be an operational nightmare given 7½
minute services on each and a lot of freight on the latter. And the
major traffic objective for the ELL is Highbury & Islington with its
Victoria Line and GN Electrics connections.

All the lines are shared with other services, some of which permeate
far into the Home Counties and bring all their operational baggage
with them. You really don't want to perpetuate all the accumulated
delays in a circular service. Circular itineraries propagate any
problems indefinitely around the service, which is why even the Circle
Line has been de-circlified.

The projected service pattern is the best one to fit travel patterns
and operational practicalities. Onward connections at Clapham
Junction will be as easy as possible – just shuffle down the
platform. At Highbury, either cross-platform or over a short bridge.

In message
, at
07:43:51 on Mon, 10 Oct 2011, Jamie Thompson
remarked:
It is known that connections can't be made at Moorgate without spending 100s
of millions though - the alterations to have a junction east of the
platforms involve adjacent building foundations - and there is basically no
way a business case would ever stand up.

I know...but it's still unfortunate. Interestingly, these foundations
don't seem to be a problem for Crossrail...

It's sufficiently 'underground' presumably.
--
Roland Perry

Roland Perry wrote:

In message
, at
07:43:51 on Mon, 10 Oct 2011, Jamie Thompson
remarked:
It is known that connections can't be made at Moorgate without spending 100s
of millions though - the alterations to have a junction east of the
platforms involve adjacent building foundations - and there is basically no
way a business case would ever stand up.

I know...but it's still unfortunate. Interestingly, these foundations
don't seem to be a problem for Crossrail...

It's sufficiently 'underground' presumably.


Yes, but the point is that the greater depth allows a wider choice of
route. You still have to avoid the foundations, because many of them
are piles that were bored upwards of 30m deep, starting from a deep
basement. Also, it's not about avoiding physically hitting the piles
themselves, but about avoiding where they put their loads into the
soil below. ;-)

On Oct 10, 9:57*pm, Roland Perry wrote:
In message
, at
07:43:51 on Mon, 10 Oct 2011, Jamie Thompson
remarked:

It is known that connections can't be made at Moorgate without spending 100s
of millions though - the alterations to have a junction east of the
platforms involve adjacent building foundations - and there is basically no
way a business case would ever stand up.

I know...but it's still unfortunate. Interestingly, these foundations
don't seem to be a problem for Crossrail...

It's sufficiently 'underground' presumably.
--
Roland Perry

....and by Crossrail, I also meant the passenger walkway tunnels et al,
which are very close to the surface (and will block anything like this
quite comprehensively).