Solving the Valley lines bottleneck at Cardiff Central?

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gareth950

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This week I've been getting the 0755 Barry Island into Cathays and every morning the train has been late due to being stuck waiting outside Cardiff Central for 10 minutes for platform 6 to clear and then again being stuck at platform 6 (for no apparent reason) for 5 - 10 minutes before moving on. The worst delay was 20 minutes, arriving into Cathays at 0850 instead of 0830, all due to congestion at Central.

I know the 0742 from Bridgend to Aberdare was delayed by 25 - 30 minutes on Tuesday due to a passenger being taken ill at Central, due to being shoved in the cattle truck conditions on that service - just 2 carriages on the peak service from Bridgend via the VOG and Barry into CDF for 0840. Passengers can't board this service after Barry at 0815 as it's full and standing from there every morning.
Whilst this train was stuck in Platform 6, obviously this was blocking the up valley lines and everything else was waiting in a queue behind it, effectively bringing the up valleys to standstill for almost 30 minutes.

So, what (if anything) can be done about this chronic bottleneck west of Cardiff Central on the valley lines? I know that Platform 8 is due to open in January, but that will only be for down valleys services. AFAIK, all up valleys services will still be crammed through platform 6 only. Even if platform 4 is connected to the up valleys, there are too many mainline trains into that platform for it to be of any significant help if P6 is blocked for any length of time.
And then there's the crossovers of services terminating in Canton or going over to the City line that trains coming from Barry/Penarth often have to wait for to get into P6 at Central.

The infrastructure at Cardiff Central just isn't fit for 2016 service level demands. :(
 
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30907

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This week I've been getting the 0755 Barry Island into Cathays and every morning the train has been late due to being stuck waiting outside Cardiff Central for 10 minutes for platform 6 to clear and then again being stuck at platform 6 (for no apparent reason) for 5 - 10 minutes before moving on. The worst delay was 20 minutes, arriving into Cathays at 0850 instead of 0830, all due to congestion at Central.

RTT says:
Monday 5 late off Barry Island, 10 late Grangetown, 11 late Cathays.
Tuesday 4L Grangetown, 6L Cathays
Wednesday 2L Grangetown, 12/14 late Central, 15 late Cathays.
Thursday 2L Grangetown, 4L Cathays
Friday 5L Grangetown, 7L Cathays.

No obvious pattern here except station overtime which is presumably due to overcrowding, and that a rolling stock issue. I'm not a local but that sounds plausible.

Reason for Wednesday delay may be problem with the preceding Radyr to Coryton which was terminated at Heath Jn - but it's noticeable that it took nearly 5 minutes for the Barry train to be platformed after the Coryton cleared, which seems slow. Can the line be resignalled to improve the throughput of eastbound trains?
 
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PHILIPE

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RTT says:
Monday 5 late off Barry Island, 10 late Grangetown, 11 late Cathays.
Tuesday 4L Grangetown, 6L Cathays
Wednesday 2L Grangetown, 12/14 late Central, 15 late Cathays.
Thursday 2L Grangetown, 4L Cathays
Friday 5L Grangetown, 7L Cathays.

No obvious pattern here except station overtime which is presumably due to overcrowding, and that a rolling stock issue. I'm not a local but that sounds plausible.

Reason for Wednesday delay may be problem with the preceding Radyr to Coryton which was terminated at Heath Jn - but it's noticeable that it took nearly 5 minutes for the Barry train to be platformed after the Coryton cleared, which seems slow. Can the line be resignalled to improve the throughput of eastbound trains?

Major Re-signalling has only recently been done and still ongoing. Platform 6. which is known as northbound to the Valleys rather than eastbound is permissive. There is no Timetable problem, so what has to be dealt with is a performance issue, i.e. speeding up station duties.
 

30907

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Major Re-signalling has only recently been done and still ongoing. Platform 6. which is known as northbound to the Valleys rather than eastbound is permissive. There is no Timetable problem, so what has to be dealt with is a performance issue, i.e. speeding up station duties.

Thanks for confirmation - I rather thought 6 was permissive working.
 

headshot119

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So could up Valleys services use platform 7 if necessary once platform 8 is available for down services?

In theory yes, but it'll depend on what southbound or terminating services are using it as to whether it'll actually be any use.
 
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I know there's no room for a Platform 9 but it always struck me as odd that two extra platforms were built in Queen Street and only one in Central.

Does anyone know for sure that Platform 8 will be bi-directional? There are only signals and train stop markers at the western/southern end (so for trains heading down from the Valleys into the Vale) and none at the eastern/northern end.

It also seems looking at the stop marker on platform 8 that the trains will stop nowhere near the station building/canopy :roll:
 

30907

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No idea what the plan is, but I think one advantage of the additional platform will be to allow terminating down trains to reverse in P7 clear of traffic instead of having to shunt to 6. I noticed during my RTT trawl that delayed down terminators were transmitting their delay to up services because of this.
 

mp01

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What are the permissive arrangements? As I understand it, it means that the following train can trundle into the platform even though it technically doesn't have signal clearance (sorry for lack of proper railway terminology here!)

But there are many times when the following train waits out west and only heads towards the platform once it's clear of the preceding train, which adds probably best part of 2 minutes. When there's only a 5 minute gap between trains this feels like a big problem.
 

louis97

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Platform 7 is already bi-directional and has been for a very long time.

7 isn't really bi-directional, you can reverse in the platform to go back to Queen Street or onto the relief lines towards Newport, but you can't be signalled into it from the Barry/Bridgend direction.

So could up Valleys services use platform 7 if necessary once platform 8 is available for down services?

After the re-signalling is complete over Christmas this year that will be possible. It will also be possible for platform 4 to be used by services towards Queen Street.

I presume in the future the plan is for the timetable to allow 4 and 6 to be used by trains towards Queen Street and 7 and 8 to be used for trains towards Grangetown/City Line. I think before this can happen the mainline timetable will need to be adjusted to free up Platform 4, this will be able to happen because services will no longer need to shunt at Cardiff West and will instead, as a result of the re-signalling, be able to go directly into Platform 0, 1 or 2.

The re-signalling sees all platforms through Cardiff Central becoming bi-directional, also the lines between Cardiff Central and Long Dyke Junction (towards Newport) and the lines between Cardiff Central and Cardiff Queen Street. There was also plans for a new bay platform, platform 5, between Platform 3 and 4 at the west end. However i'm not really sure how this is progressing and whether this will be ready for the Christmas re-signalling.
 

gareth950

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7 isn't really bi-directional, you can reverse in the platform to go back to Queen Street or onto the relief lines towards Newport, but you can't be signalled into it from the Barry/Bridgend direction.



After the re-signalling is complete over Christmas this year that will be possible. It will also be possible for platform 4 to be used by services towards Queen Street.

I presume in the future the plan is for the timetable to allow 4 and 6 to be used by trains towards Queen Street and 7 and 8 to be used for trains towards Grangetown/City Line. I think before this can happen the mainline timetable will need to be adjusted to free up Platform 4, this will be able to happen because services will no longer need to shunt at Cardiff West and will instead, as a result of the re-signalling, be able to go directly into Platform 0, 1 or 2.

The re-signalling sees all platforms through Cardiff Central becoming bi-directional, also the lines between Cardiff Central and Long Dyke Junction (towards Newport) and the lines between Cardiff Central and Cardiff Queen Street. There was also plans for a new bay platform, platform 5, between Platform 3 and 4 at the west end. However i'm not really sure how this is progressing and whether this will be ready for the Christmas re-signalling.

There's definitely not going to be a Platform 5 a Central anytime soon, I can confidently say that. No visible building work for such a platform has taken place.

The WG probably ordered it to be put on hold, as the magical Metro is coming sometime in the indefinite distant future to solve all the problems on the valley lines.
 
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headshot119

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7 isn't really bi-directional, you can reverse in the platform to go back to Queen Street or onto the relief lines towards Newport, but you can't be signalled into it from the Barry/Bridgend direction.



After the re-signalling is complete over Christmas this year that will be possible. It will also be possible for platform 4 to be used by services towards Queen Street.

I presume in the future the plan is for the timetable to allow 4 and 6 to be used by trains towards Queen Street and 7 and 8 to be used for trains towards Grangetown/City Line. I think before this can happen the mainline timetable will need to be adjusted to free up Platform 4, this will be able to happen because services will no longer need to shunt at Cardiff West and will instead, as a result of the re-signalling, be able to go directly into Platform 0, 1 or 2.

The re-signalling sees all platforms through Cardiff Central becoming bi-directional, also the lines between Cardiff Central and Long Dyke Junction (towards Newport) and the lines between Cardiff Central and Cardiff Queen Street. There was also plans for a new bay platform, platform 5, between Platform 3 and 4 at the west end. However i'm not really sure how this is progressing and whether this will be ready for the Christmas re-signalling.

I agree that all platforms will be bi-directional, but I don't agree that the eventual plan is to use Platform 4 as a regular platform for the Valley lines services, the mainline timetable would need a massive recast to free it up for regular use. Running trains straight into 0,1, and 2 to save them shunting isn't that easy, as the trains lay over for a long time, and I can't see that changing as it'll effect timetable resilience.

Platform 5 is on hold, and won't make it in over Christmas, but could be easily added at a later date; certainly all the data exists in the signalling system for it.

All in all the new layout will be much more flexible.
 
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I presume in the future the plan is for the timetable to allow 4 and 6 to be used by trains towards Queen Street and 7 and 8 to be used for trains towards Grangetown/City Line. I think before this can happen the mainline timetable will need to be adjusted to free up Platform 4, this will be able to happen because services will no longer need to shunt at Cardiff West and will instead, as a result of the re-signalling, be able to go directly into Platform 0, 1 or 2.

The re-signalling sees all platforms through Cardiff Central becoming bi-directional, also the lines between Cardiff Central and Long Dyke Junction (towards Newport) and the lines between Cardiff Central and Cardiff Queen Street. There was also plans for a new bay platform, platform 5, between Platform 3 and 4 at the west end. However i'm not really sure how this is progressing and whether this will be ready for the Christmas re-signalling.

Does this mean at the moment trains from the East (Newport/London) can't go into platforms 0, 1 and 2?

Sorry for the question I never thought of that but it would seem to be true.

If that's the case will platform four basically be freed up for Valley Services leaving 0,1,2&3 for Main Line and 4,6,7&8 for local/Valley/'Metro'?
 

louis97

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I agree that all platforms will be bi-directional, but I don't agree that the eventual plan is to use Platform 4 as a regular platform for the Valley lines services, the mainline timetable would need a massive recast to free it up for regular use. Running trains straight into 0,1, and 2 to save them shunting isn't that easy, as the trains lay over for a long time, and I can't see that changing as it'll effect timetable resilience.

Platform 5 is on hold, and won't make it in over Christmas, but could be easily added at a later date; certainly all the data exists in the signalling system for it.

All in all the new layout will be much more flexible.

The whole purpose of the bi-directional lines out to Long Dyke is to allow trains to cross the layout at faster crossovers away from the slow ladder at Cardiff West, with that then reducing the number of shunt moves. It will be interesting to see if this does happen, seems an awful waste if its not going to become the norm - especially given the benefits of reducing required turnaround times and maximising unit diagram efficiency.

Does this mean at the moment trains from the East (Newport/London) can't go into platforms 0, 1 and 2?

Sorry for the question I never thought of that but it would seem to be true.

If that's the case will platform four basically be freed up for Valley Services leaving 0,1,2&3 for Main Line and 4,6,7&8 for local/Valley/'Metro'?

Indeed, Platform 0, 1 and 2 are only available for trains travelling in the up (London) direction at present.

Potentially yes, the re-signalling included a new crossover to allow access from Platform 4 to the Valley Lines, so I would certainly expect it to be used in peak.
 

PHILIPE

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7 isn't really bi-directional, you can reverse in the platform to go back to Queen Street or onto the relief lines towards Newport, but you can't be signalled into it from the Barry/Bridgend direction.

My mistake. I have seen trains run through but this was to get round a failure stuck in Platform 6. Also, I've seen loaded passsenger trains depart westwards from Platform 6 although not supposed to. ECS movements OK. Special arrangements.
Platform 7, then, similar to Platform 7 at Shrewsbury and, from quite recently, Platform 1 at Hereford. No access from south direction.
 

edwin_m

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Platforms 0-2 will actually be easier for terminating main line trains after the re-signally than higher numbered platforms, because they don't have to cross the flow of freight through the Relief lines and centre roads (although that isn't anything like what it used to be). So I'd not be surprised to see most main line terminators from the east using 0-2, with the exception of any routed via the Reliefs.
 
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Dai Corner

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Perhaps this should be in the History section, but I was wondering about service patterns in the past. Have there always been through trains between Penarth / Vale of Glamorgan line and the Valleys or was there a time when they terminated at Central and Queen Street / Bute Road?
 

krus_aragon

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Perhaps this should be in the History section, but I was wondering about service patterns in the past. Have there always been through trains between Penarth / Vale of Glamorgan line and the Valleys or was there a time when they terminated at Central and Queen Street / Bute Road?

Pre-grouping, the Barry Railway used to use Cardiff Riverside, a station adjacent to P7 at Central (General/GWR), with some services extended down the river to Clarence Road. ( The now demolished south entrance to Central was originally the station building for Riverside). Some Taff Vale services to Penarth and Cadoxton also ran to Riverside/Clarence Road rather than Central (GWR) and Queen St (TVR).

My 1902 reprint shows the Barry Railway operating Pontypridd services (via Ely) from Clarence Road and Riverside. TVR services to Pontypridd, Aberdare and Merthyr ran from Central and Queen St, and whilst listed in a separate table, most services appear to run through to Penarth or Cadoxton.

Services to Caerphilly and Ystrad Mynach were operated by the Rhymney Railway from Cardiff Parade rather than Queen St, so no scope for through running.
 
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Dai Corner

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Pre-grouping, the Barry Railway used to use Cardiff Riverside, a station adjacent to P7 at Central (General/GWR), with some services extended down the river to Clarence Road. ( The now demolished south entrance to Central was originally the station building for Riverside). Some Taff Vale services to Penarth and Cadoxton also ran to Riverside/Clarence Road rather than Central (GWR) and Queen St (TVR).

My 1902 reprint shows the Barry Railway operating Pontypridd services (via Ely) from Clarence Road and Riverside. TVR services to Pontypridd, Aberdare and Merthyr ran from Central and Queen St, and whilst listed in a separate table, most services appear to run through to Penarth or Cadoxton.

Services to Caerphilly and Ystrad Mynach were operated by the Rhymney Railway from Cardiff Parade rather than Queen St, so no scope for through running.

Thanks for the info - I must find time to study some old maps of central Cardiff.
 

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Parallel

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Will there be issues with trains terminating at platforms 1/2 at Cardiff? There are significantly more trains that head eastbound from Cardiff, than westbound. Would it make platforms 1/2 a bottleneck for mainline services?
 

edwin_m

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A good place to start would be the Railway Junction Diagrams published by the Railway Clearing House, used for calculating revenue according to the ownership of the route travelled.

Wikimedia Commons has a full set of the 1914 diagrams available, showing pre-grouping ownership: https://commons.wikimedia.org/wiki/Category:Railways_Junctions_Diagram_1914

Or for serious time-wasting how about http://www.railmaponline.com/UKIEMap.php
--- old post above --- --- new post below ---
Will there be issues with trains terminating at platforms 1/2 at Cardiff? There are significantly more trains that head eastbound from Cardiff, than westbound. Would it make platforms 1/2 a bottleneck for mainline services?

I believe platform 0 will also be lengthened to be useable by more or most trains. With three platforms, allowing an average of 20min for each train to enter, occupy and clear, that's nine trains per hour. Some will take more but others will take a lot less particularly if they are eastbounds passing through rather than terminators. And there is still the option to cross one over to 3, double-stack shorter trains or shunt out towards Canton.
 
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Dai Corner

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The junction diagrams have excellent detail and I like the way railmaponline makes it easy to relate historic lines to current features.

Another good resource is http://www.sabre-roads.org.uk/maps/ which has scans of OS and other maps from different years.
 

anthony263

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Once the bottlenecks at Central are sorted there are others around Wales and on the Valley Lines network. The Newport road bridge at the northern end of central station must cause headaches and I do wish it would be possible to install a new wider bridge which can accommodate 4 tracks or even 3 would be better.
 
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Once the bottlenecks at Central are sorted there are others around Wales and on the Valley Lines network. The Newport road bridge at the northern end of central station must cause headaches and I do wish it would be possible to install a new wider bridge which can accommodate 4 tracks or even 3 would be better.

The bridge at Queen Street you mean?

I was looking at this the other day and wondering if because there are now four through platforms at Queen Street should the bridge have four tracks given that there are four tracks directly to the north (at the moment four tracks become two to cross the bridge then become four in the station) however I can't see a way to increase capacity between Queen Street and Central - that surely is the bottle neck and unless that gets solved there's no point in sorting the bridge?*



* Unless the Welsh Govt pulls there finger out and the Metro becomes a reality and trains start/terminate at Queen Street or we get an expanded network in the Bay with through trains from the Valleys?
 
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