"andypurk" wrote in message
newsp.vzfzca0iyfeo2q@pc-prime...
On Fri, 29 Jul 2011 18:27:41 +0100, Paul Corfield
wrote:

One small question - is it still the case that there will be a flat
junction south of Blackfriars where the LOB and E&C routes diverge?

I can't imagine anything fancy like flyunders can be put in place
given the CX line alignment. Nonetheless that is going to some
challenge to get 18 tph in both directions across a flat junction
without too many conflicts given the pretty long distance nature of
many of the services and risks of late running.

The flyover/dive under for the New Cross Gate route trains will be to the
east of London Bridge. Thameslink services will use the platforms
currently used by Charing Cross trains and the existing two track route
over Borough Market. The Charing Cross services will generally be using
the new platforms to be built to the south of platforms 1-6 and the new
bridge over Borough Market recently put in place (but with no track due to
be laid until later on in the project).

I believe Paul C was actually asking about the flat crossing moves needed
immediately south of Blackfriars. There's definitely a conflict there
between the 18 tph coming from London Bridge, and the 6 tph towards Elephant
and Castle. Of course trains in the opposite directions don't cross each
other, they just have to merge...

Therefore his point is that there is only very limited space along the line
of route to fit in an underpass - because of the proximity of the CX
approach lines; but perhaps a flyover for the Thameslink down line towards
Elephant would be feasible, even if unusually high...

Paul S

On Sat, 30 Jul 2011 18:39:13 +0100, Paul Scott
wrote:



"andypurk" wrote in message
newsp.vzfzca0iyfeo2q@pc-prime...
On Fri, 29 Jul 2011 18:27:41 +0100, Paul Corfield
wrote:

One small question - is it still the case that there will be a flat
junction south of Blackfriars where the LOB and E&C routes diverge?

I can't imagine anything fancy like flyunders can be put in place
given the CX line alignment. Nonetheless that is going to some
challenge to get 18 tph in both directions across a flat junction
without too many conflicts given the pretty long distance nature of
many of the services and risks of late running.

The flyover/dive under for the New Cross Gate route trains will be to
the east of London Bridge. Thameslink services will use the platforms
currently used by Charing Cross trains and the existing two track route
over Borough Market. The Charing Cross services will generally be using
the new platforms to be built to the south of platforms 1-6 and the new
bridge over Borough Market recently put in place (but with no track due
to be laid until later on in the project).

I believe Paul C was actually asking about the flat crossing moves
needed immediately south of Blackfriars. There's definitely a conflict
there between the 18 tph coming from London Bridge, and the 6 tph
towards Elephant and Castle. Of course trains in the opposite
directions don't cross each other, they just have to merge...

Therefore his point is that there is only very limited space along the
line of route to fit in an underpass - because of the proximity of the
CX approach lines; but perhaps a flyover for the Thameslink down line
towards Elephant would be feasible, even if unusually high...


So he did, I wasn't paying attention. However the flat junction with a 3:1
split isn't so bad, especially as the route will be under ATO through the
junction and presumably there will be the opportunity to have a bit of
recovery time at Elephant and Castle or London Bridge for the Up trains
(due to having more than one platform available) allowing train to arrive
at the junction at the correct time. I would imagine that the junction at
St. Pancras may be more of an operational problem with only a single
platform to accommodate the merging trains from two routes.

--
Using Opera's revolutionary email client: http://www.opera.com/mail/

"andypurk" wrote

So he did, I wasn't paying attention. However the flat junction with a 3:1
split isn't so bad, especially as the route will be under ATO through the
junction and presumably there will be the opportunity to have a bit of
recovery time at Elephant and Castle or London Bridge for the Up trains
(due to having more than one platform available) allowing train to arrive
at the junction at the correct time. I would imagine that the junction at
St. Pancras may be more of an operational problem with only a single
platform to accommodate the merging trains from two routes.

AIUI in normal working there will only be one up platform for Thameslink
trains at each of London Bridge and Elephant & Castle, although there will
be access to other platforms for exceptional working. Clearly a high
standard of operating will be needed at Blackfriars Junction where 18 tph up
London Bridge trains have to cross 6 tph down Elephant trains. The timetable
will no doubt be based on parallel working, i.e. up and down London Bridge
trains will pass at Blackfriars Junction, as will up and dowm Elephant
trains. However, the plans show three Thameslink tracks between Blackfriars
station and junction, so in perturbed working a down Elephant train will be
able to clear Blackfriars station and wait short of the junction for a path
across the junction. Meanwhile a following down London Bridge train will be
able to overtake and move on to the spur down to Metropolitan Junction.

Peter

"Paul Corfield" wrote

Thanks to everyone who commented - the responses confirm what I
suspected which is that it will be something of a challenge but
timetabling can certainly minimise the risk of conflicting moves.

Are the plans to which you refer publicly available on the net? The
nearest I could dig out was an old post on the now defunct London
Connections blog from several years ago. The diagram doesn't have the
subtle detail to which you refer.

I haven't come across the plans on the net -- and my information could be
out of date, as it comes from the February 2000 MR.

Peter

"Peter Masson" wrote in message
...

"Paul Corfield" wrote

Are the plans to which you refer publicly available on the net? The
nearest I could dig out was an old post on the now defunct London
Connections blog from several years ago. The diagram doesn't have the
subtle detail to which you refer.

I haven't come across the plans on the net -- and my information could be
out of date, as it comes from the February 2000 MR.

I was thinking Feb 2007 MR, was that a typo Peter?

The drawings do however show a number of options for routeing trains across
the junction in question, as you mention...

Paul S

"Paul Scott" wrote in message
...


"Peter Masson" wrote in message
...

"Paul Corfield" wrote

Are the plans to which you refer publicly available on the net? The
nearest I could dig out was an old post on the now defunct London
Connections blog from several years ago. The diagram doesn't have the
subtle detail to which you refer.

I haven't come across the plans on the net -- and my information could be
out of date, as it comes from the February 2000 MR.

I was thinking Feb 2007 MR, was that a typo Peter?

The drawings do however show a number of options for routeing trains
across the junction in question, as you mention...

Thanks. I was looking for the later (2007) version but only found the
earlier (2000) version. The later one seems to provide a little more
flexibility at Blackfriars Junction, but retains the ability for a
southbound Elephant train to wait for a path across the junction without
impeding a following down London Bridge train from accessing the spur to
Metropolitan Junction.

Now that the routeing of Thameslink trains is becoming clearer a further
conflict has been removed. Thameslink Elephant & Castle trains will all run
via the Catford Loop, so won't conflict with trains from the Blackfriars
terminal platforms running via Herne Hill.

Peter