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-   -   Highly random question about the Hounslow loop (https://www.londonbanter.co.uk/london-transport/1853-highly-random-question-about-hounslow.html)

Tom Anderson June 16th 04 05:08 PM

Highly random question about the Hounslow loop
 
Am i right in thinking that it's normal double track downward from Barnes
in the direction of Richmond and Reading? And thus that Barnes looks like:

to Hounslow
\ \---------
\ ###
\--------- to
--------------- Clapham Junction
###
---------------
to Richmond

Doesn't that mean that local services via Richmond have to share with
mainline services to Reading? Doesn't that suck? Or is the Reading service
not a 'real' main line?

Thanks,
tom

--
For one thing at least is almost certain about the future, namely, that very much of it will be such as we should call incredible. -- Olaf Stapledon


Mark Townend June 16th 04 07:43 PM

Highly random question about the Hounslow loop
 
"Tom Anderson" wrote in message
...
Am i right in thinking that it's normal double track downward from Barnes
in the direction of Richmond and Reading? And thus that Barnes looks like:

to Hounslow
\ \---------
\ ###
\--------- to
--------------- Clapham Junction
###
---------------
to Richmond


More Like . .

Hounslow
~BARNES~
\ \
\ \ ##1##
\ *---*----------*----- Slow
\ / \ \ UP
X --*----------*--- Fast
/ \ / ##2##
---*---+-- Clapham Junction
\ ##3##
---*-----*-*------------*--- Fast
\ \ / DOWN
--------*--------*----- Slow
##4##
Richmond


Doesn't that mean that local services via Richmond have to share with
mainline services to Reading? Doesn't that suck? Or is the Reading service
not a 'real' main line?


The Reading Fasts usually run on the Down Slow and can thus overtake
stoppers going to Richmond or Hounslow, and additionally are able to
traverse Barnes Junction in parallel with the Hounslows without conflict.
Not sure which line UP Fast trains use habitually, but the Slow could be
used if a parallel movement is coming off the Houslow line.

The timetable is a compromise. On the shared sections west of Barnes, the
Stopping trains have to precede the Fasts by a margin equal to the normal
platfrom reoccupation time plus the difference in running time between the
shared sections extremites, perhaps the Stopper turning off at Twickenham or
Staines. The difference in running time is the limiting factor on capacity
as it effectively freezes out regular parts of the hour that could be used
by a more frequent all stopping service. A common problem with this type of
service mix is late presentation of a longer distance Fast train at a
junction merging with shorter distance Stopping trains. The Stopper is less
likely to be delayed on its shorter simpler network, but may be held a
minute or 2 due to priority rules. Anything more and it must go or else the
local services could start to decay. Now the Fast has to follow it in until
the next passing point or diverge.

Some Fasts run via the Hounslow loop in the peaks, and for the brief period
when there were 4 trains an hour all day to and from Reading, 2 of those ran
via Hounslow with some stops in place of Twickenham and Richmond.

--
Mark



Mark Townend June 16th 04 07:51 PM

Highly random question about the Hounslow loop
 

"Mark Townend" wrote in message
...

The Reading Fasts usually run on the Down Slow and can thus overtake
stoppers going to Richmond or Hounslow, and additionally are able to
traverse Barnes Junction in parallel with the Hounslows without conflict.
Not sure which line UP Fast trains use habitually, but the Slow could be
used if a parallel movement is coming off the Houslow line.


Sorry, meant the Fast Richmond trains could use the Up Fast in parallel with
a Hounslow Stopper on the Up Slow through Barnes Junction.

--
Mark



Tom Anderson June 17th 04 08:48 PM

Highly random question about the Hounslow loop
 
On Wed, 16 Jun 2004, Mark Townend wrote:

"Tom Anderson" wrote in message
...

Am i right in thinking that it's normal double track downward from
Barnes in the direction of Richmond and Reading? Doesn't that mean
that local services via Richmond have to share with mainline services
to Reading? Doesn't that suck?


Firstly, thanks for the info!

The timetable is a compromise. On the shared sections west of Barnes,
the Stopping trains have to precede the Fasts by a margin equal to the
normal platfrom reoccupation time plus the difference in running time
between the shared sections extremites, perhaps the Stopper turning off
at Twickenham or Staines. The difference in running time is the limiting
factor on capacity as it effectively freezes out regular parts of the
hour that could be used by a more frequent all stopping service.


I guess that's the answer to the last bit - no, you can't run frequent
local services here without screwing over the fast trains. Obvious, i
suppose!

tom

--
Remember when we said there was no future? Well, this is it.


Colin Rosenstiel July 16th 04 11:33 PM

Highly random question about the Hounslow loop
 
In article , (Mark
Townend) wrote:

More Like . .

Hounslow
~BARNES~
\ \
\ \ ##1##
\ *---*----------*----- Slow
\ / \ \ UP
X --*----------*--- Fast
/ \ / ##2##
---*---+-- Clapham Junction
\ ##3##
---*-----*-*------------*--- Fast
\ \ / DOWN
--------*--------*----- Slow
##4##
Richmond


I'm sure the fasts are on the outside from Clapham Junction to Barnes.

--
Colin Rosenstiel

Mr Nobody July 17th 04 08:43 AM

Highly random question about the Hounslow loop
 

"Colin Rosenstiel" wrote in message
...
In article , (Mark
Townend) wrote:

More Like . .

Hounslow
~BARNES~
\ \
\ \ ##1##
\ *---*----------*----- Slow
\ / \ \ UP
X --*----------*--- Fast
/ \ / ##2##
---*---+-- Clapham Junction
\ ##3##
---*-----*-*------------*--- Fast
\ \ / DOWN
--------*--------*----- Slow
##4##
Richmond


I'm sure the fasts are on the outside from Clapham Junction to Barnes.

--
Colin Rosenstiel



The line naming doesn't actually match the use between Clapham and Barnes
for some reason.

The slow lines are indeed the outer pair.

Mr Nobody.



Colin Rosenstiel July 17th 04 10:58 PM

Highly random question about the Hounslow loop
 
In article ,
(Mr Nobody) wrote:

"Colin Rosenstiel" wrote in message
...
In article ,

(Mark Townend) wrote:

More Like . .

Hounslow
~BARNES~
\ \
\ \ ##1##
\ *---*----------*----- Slow
\ / \ \ UP
X --*----------*--- Fast
/ \ / ##2##
---*---+-- Clapham Junction
\ ##3##
---*-----*-*------------*--- Fast
\ \ / DOWN
--------*--------*----- Slow
##4##
Richmond


I'm sure the fasts are on the outside from Clapham Junction to Barnes.


The line naming doesn't actually match the use between Clapham and
Barnes for some reason.

The slow lines are indeed the outer pair.


How weird! The outer lines have always been fast in practice in my
lifetime.

--
Colin Rosenstiel


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