South East Wales - New service to Bristol and new stations opening: how should these be served?

[Snow1964]

That potentially means closing the signals up and reducing the line speed as they become under braked. In the up direction the block signal for the tunnel is right at the portal, the single yellow is at the Tunnel Jn platform end 1684m away, the green is at the M4 motorway bridge 1469m behind that. Prior to the re-signaling the block signal was at the end of the Up Loop. Same applies on the down, the block signal is at the portal, the single yellow is 1969m back also protecting the exit to the Down Loop, the green 1776m prior to that. Again, prior to the re-signaling, the block signal was at the end of the Down Loop.

I wasn't thinking so much about moving or closing the signals as adding banner repeaters on tunnel approach, so a driver still a way from the signal knows if it has cleared, and can stop braking, and accelerate.

With the next stop signal 4-5 miles away at other end of the tunnel, don't then need to trundle through a single yellow. Aim is to allow driver to accelerate earlier which will meaning clearing the section quicker.

 

[The Planner]

I wasn't thinking so much about moving or closing the signals as adding banner repeaters on tunnel approach, so a driver still a way from the signal knows if it has cleared, and can stop braking, and accelerate.

With the next stop signal 4-5 miles away at other end of the tunnel, don't then need to trundle through a single yellow. Aim is to allow driver to accelerate earlier which will meaning clearing the section quicker.

Banner repeaters are for sighting issues, if there aren't any there then you wouldn't put them in. The tunnel has 2 aspect distant signals around ¾ mile from the exits, as soon as a train exits, the entry will go green.

 

[Rhydgaled]

the plans were drawn up by the Burns Commision established following the scrapping of plans for an M4 relief road south of Newport

Interestingly the Burns Commision appears to propose abolishing the distinction between 'main' and 'relief' between Cardiff and Severn Tunnel Junction with the top pair of lines west of Bishton flyover (currently the mains) being mainly used for local, commuting services in future. The bottom pair of lines (currently the reliefs) would be mainly used for inter-city services. The Burns Commision report points out that "This configuration would allow for other branch lines to connect to the main line, such as the Ebbw Vale and Marches line" however it does not say what would happen to freight services. Would mixing freight and InterCity services on the current relief lines work?

Perhaps someone can confirm, but the illustrations of the new station proposals in the consultation document appear to have the platforms suituated on what are currently the releif lines. If I'm correct, that means the platforms will be in the wrong place if/when the Burns Commision proposals are implemented, since only fast passenger (non-stopping) and freights would then be using those lines.

Good to see this starting to move forward. Any additional services need to run through from west of Cardiff. Cardiff Central already struggles to cope with the number of terminating trains, as discussed elsewhere. When the tfw Cheltenham goes to a regular hourly service, perhaps it could interwork with the Swanline to avoid terminating services and provide east-west connectivity across Cardiff with the proposed new stations.

As noted above, there are plans to upgrade the relief lines to for frequent use by passenger services. Since the GWML west of Cardiff is only double-track, there is not the capacity for everything arriving in Cardiff from the east to continue west along the main line - at least not if you want to be able to give Pontyclun, Llanharan and Pencoed a decent service. I think providing much of an uplift in services between Cardiff and Bridgend will need an infrustructure upgrade. Building a new station on this stretch (perhaps the Miskin one mentioned in KeolisAmey's franchise announcement) with platforms off the main running lines (so that stoppers can be looped for fast trains to overtake) is probably the least expensive option to acheive that.

I would certainly support the (hourly) Swanline service running through to either Cheltenham or Bristol though, and additional services as soon as the capacity issue(s) can be resolved.

I wonder what is happening regarding the Cardiff Parkway station proposed for the St.Mellons area? This is part of a bigger scheme put forward by a developer who would like to build a business park at the location. Friends of the Earth and others objected and the Welsh Government ‘called in’ the scheme over 1 year ago since when, we have heard nothing.

I think Cardiff Parkway is/was intended to have four platforms; I'm not really in favour of that idea as I feel strongly that only the stoppers should call and not fast/semi-fast trains to London, Manchester, Chester, Portsmouth, Nottingham etc. so only needs platforms on whichever pair of lines becomes the one for stoppers. That said, at least 4 platforms would be future-proof if, when the relief lines are upgraded to passenger speeds, they decide to change which pair of lines is used for what.

Tfw saying trains will have level boarding so expect more class 756s.

TfW might not actually need to do anything fleet wise. If the Bristol services end up being run by GWR then in the smallest option TfW might only need to add calls to their existing Cheltenham services, which are already planned to be 231s so level boarding would be provided without any change of TfW fleet. If I recall correctly only 1 GWR service per hour calls at Patchway and that is the Cardiff-Penzance service. If this was still just Cardiff-Taunton and worked (or expected to be) by class 165/166 units I wouldn't have been surprised to see the proposed new stations added as additional stops on that service and no additional services provided by either operator.

Surely capacity through the Severn Tunnel would hinder additional stopping trains being introduced through there?

As I understand it, only one train is allowed in, in each direction. 2 GWR Padds, 2 GWR locals and a freight per hour in each direction pretty much fills up paths.

That is 5 trains per hour. The tunnel can take more than that. Severn Tunnel East to West is timed as absolute block with 2 minutes bunce on top (it probably doesnt need as much as 2). A GWR 800 can traverse the tunnel in 3½ minutes, so its a 5½ minute headway for those. A 165 takes 4 minutes, so a 6 minute headway. A Class 4 takes 4½ normally, a 2200 ton Class 6 takes 6 minutes, so a 8 minute headway. If you assume the above and a class 6, that is 31 minutes of the hour used.

Looking at an old PDF 'Rules Of The Plan', headways through the tunnel appear to be 5 minutes (12tph?) unless following a freight (6 minutes) or 7 minutes if following a freight that has been or will be looped in one of two places.

Here's a question could more freight be routed via Gloucester as most of it isn't highly time sensitive?

Doesn't most freight already go via Gloucester to avoid steep gradients in and out of the tunnel?

surely Severn Tunnel Junction-Cheltenham/Gloucester-Swindon electrication is a priority.

It should be, but that's because things like Didcot-Oxford-Banbury-Coventry should have been done by now. Since they haven't been done, they are the priority for electrification.

Newport re-signaling is only around 12-13 years old, so no one is going to make any significant changes.

Except that, as I have discussed above, there are now plans to use the relief lines for passenger trains much more often.

 

[Snow1964]

Interestingly the Burns Commision appears to propose abolishing the distinction between 'main' and 'relief' between Cardiff and Severn Tunnel Junction with the top pair of lines west of Bishton flyover (currently the mains) being mainly used for local, commuting services in future. The bottom pair of lines (currently the reliefs) would be mainly used for inter-city services. The Burns Commision report points out that "This configuration would allow for other branch lines to connect to the main line, such as the Ebbw Vale and Marches line" however it does not say what would happen to freight services. Would mixing freight and InterCity services on the current relief lines work?

Perhaps someone can confirm, but the illustrations of the new station proposals in the consultation document appear to have the platforms suituated on what are currently the releif lines. If I'm correct, that means the platforms will be in the wrong place if/when the Burns Commision proposals are implemented, since only fast passenger (non-stopping) and freights would then be using those lines.

As noted above, there are plans to upgrade the relief lines to for frequent use by passenger services. Since the GWML west of Cardiff is only double-track, there is not the capacity for everything arriving in Cardiff from the east to continue west along the main line

I think Cardiff Parkway is/was intended to have four platforms; I'm not really in favour of that idea as I feel strongly that only the stoppers should call and not fast/semi-fast trains to London, Manchester, Chester, Portsmouth, Nottingham etc. so only needs platforms on whichever pair of lines becomes the one for stoppers. That said, at least 4 platforms would be future-proof if, when the relief lines are upgraded to passenger speeds, they decide to change which pair of lines is used for what.

Because the Burns Commission was tasked with looking at it, they did it from fresh eyes. They realised the current main and relief is hangover from slow coal trains from the valleys, getting them to docks on Southern side. Clearly they thought why not swap for 21st century usage.

I realise the two pairs are not exactly parallel but alignment is similar, so if looking at it without historical hang-up they see swapping the usage as better. Of course the slower relief lines might need higher speed limit, but conversely the fast might not need as much. A lot of the route is more like 90-100mph than 125mph anyway.

As for freight, there are some sections with fifth and sixth tracks, another hangover of earlier freight with long reception or holding tracks, it really ought to be possible to reconfigure some of these to middle overtaking loop on 3 track section (alongside the 2 track other pair).

Although some land with former yards has been sold off there remains huge lengths of disused trackbed alongside current lines in South Wales. What is possible really depends on how much want to spend as opposed to space is never going to be available for any improvements

 

[The Planner]

As noted above, there are plans to upgrade the relief lines to for frequent use by passenger services

Nothing to stop that happening now.

Looking at an old PDF 'Rules Of The Plan', headways through the tunnel appear to be 5 minutes (12tph?) unless following a freight (6 minutes) or 7 minutes if following a freight that has been or will be looped in one of two places.

No, block through the tunnel. 4 either side.

Doesn't most freight already go via Gloucester to avoid steep gradients in and out of the tunnel?

No, if they fit they can get a path.

Except that, as I have discussed above, there are now plans to use the relief lines for passenger trains much more often.

And as above, you can do it now

 

[Rhydgaled]

Because the Burns Commission was tasked with looking at it, they did it from fresh eyes. They realised the current main and relief is hangover from slow coal trains from the valleys, getting them to docks on Southern side. Clearly they thought why not swap for 21st century usage.

I realise the two pairs are not exactly parallel but alignment is similar, so if looking at it without historical hang-up they see swapping the usage as better. Of course the slower relief lines might need higher speed limit, but conversely the fast might not need as much. A lot of the route is more like 90-100mph than 125mph anyway.

I don't think there's any 125mph in Wales - the fastest bit I think is a four mile stretch (two miles either side of Pyle station) at 90mph with a HST differential allowing 100mph. between Cardiff and Severn Tunnel Junction there are a few stretches at 90 and 95 (again mostly HST differentials) but nothing above 95mph unless the PDF I'm looking at is out of date.

If what the Burns Commission have recommended is more-appropriate for future traffic then I think it is important this is fed into the consultation on the new stations to ensure the new platforms are built in the right place. Putting the platforms on the northern pair of lines, as per the Burns report, might also allow one or two of them be to openned prior to any additional services being provided, but putting the calls in the existing Ebbw Vale and/or Cheltenham services as appropriate.

As for freight, there are some sections with fifth and sixth tracks, another hangover of earlier freight with long reception or holding tracks, it really ought to be possible to reconfigure some of these to middle overtaking loop on 3 track section (alongside the 2 track other pair).

Although some land with former yards has been sold off there remains huge lengths of disused trackbed alongside current lines in South Wales.

Indeed; I've been thinking along the same lines although I don't know if the remaining yards are owned by Network Rail or by the freight customers, who might not be willing to cooperate.

Nothing to stop that happening now.

True; I think I've been along the releif lines on a HST one Sunday (presumably the mains were closed for maintenance, or possibily electrification works), but isn't the linespeed a fair bit slower than the mains or has that upgrade work been done now?

No, block through the tunnel. 4 either side.

Interesting; is the document I'm looking at wrong, out of date or am I just looking at the wrong part of it (screenshot follows)?

 

[The Planner]

Interesting; is the document I'm looking at wrong, out of date or am I just looking at the wrong part of it (screenshot follows)?
View attachment 149290

Its nigh on 7 years out of date.

 

[Snow1964]

Reminder that consultation closes 14th January

New stations between Cardiff Central and Severn Tunnel Junction with improved cross border services

1. Read the information pack (download) 2. Answer the survey 3. Read the FAQs (download), if you have outstanding questions. Tell us your thoughts on our plans for new stations between Cardiff Central and Severn Tunnel Junction, and new train service proposals We want

haveyoursay.tfw.wales

The proposals document (English version) is

https://ehq-production-europe.s3.eu-west-1.amazonaws.com/1797eeb155e87cbe21d5ee6c414fd290dcfbc6d9/original/1697540910/9f55bca9080d59e8a03bb8112c5e0749_Sew_new_stations_consultation_pack_english.pdf?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIA4KKNQAKICO37GBEP%2F20240106%2Feu-west-1%2Fs3%2Faws4_request&X-Amz-Date=20240106T150747Z&X-Amz-Expires=300&X-Amz-SignedHeaders=host&X-Amz-Signature=de546947a6740c81b60848df4d686fc8fceb4532461a4a00247f24be449c368b

In the FAQs it says 170m platforms to allow 6 or 8 car trains (depending on type), so seemed to have allowed for 8car (20m) EMUs

 

[anthony263]

Reminder that consultation closes 14th January

New stations between Cardiff Central and Severn Tunnel Junction with improved cross border services

1. Read the information pack (download) 2. Answer the survey 3. Read the FAQs (download), if you have outstanding questions. Tell us your thoughts on our plans for new stations between Cardiff Central and Severn Tunnel Junction, and new train service proposals We want

haveyoursay.tfw.wales

The proposals document (English version) is

https://ehq-production-europe.s3.eu-west-1.amazonaws.com/1797eeb155e87cbe21d5ee6c414fd290dcfbc6d9/original/1697540910/9f55bca9080d59e8a03bb8112c5e0749_Sew_new_stations_consultation_pack_english.pdf?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIA4KKNQAKICO37GBEP%2F20240106%2Feu-west-1%2Fs3%2Faws4_request&X-Amz-Date=20240106T150747Z&X-Amz-Expires=300&X-Amz-SignedHeaders=host&X-Amz-Signature=de546947a6740c81b60848df4d686fc8fceb4532461a4a00247f24be449c368b

In the FAQs it says 170m platforms to allow 6 or 8 car trains (depending on type), so seemed to have allowed for 8car (20m) EMUs

They'll have quite a choice of emus to choose from let's hope the wires reach Bristol TM, Oxford and Swansea.

They need to look at getting Brackla station open ASAP too

 

[Western 52]

Is Brackla actually approved and funded?

 

[tiptoptaff]

The signalling on the reliefs between STJ and Cardiff doesn't need changing to up the linespeed, it's already identical to the mains in both directions. Spacing and aspects are all in the same places, up and down, on all 4 lines.

 

[Rhydgaled]

They'll have quite a choice of emus to choose from let's hope the wires reach Bristol TM, Oxford and Swansea.

Yes, I hope they make progress on the wires soon (particularly Oxford, since we could do with some/all of Cardiff-Bridgend being (re)quadrupled* before spending millions installing masts for OHLE and last time I mentioned wires to Bristol TM somebody said there are major works going on with the train shed roof which should be finished before the wires go up).

* was any of it ever more than double track in the past?

They need to look at getting Brackla station open ASAP too

Is Brackla actually approved and funded?

Apparently a 'cutting the first sod' event was carried out for Brackla many years ago but I cannot remember whether it made it into the plans for the KeolisAmey franchise - I'm over 90% certain there was a Miskin station on the KeolisAmey plans but I cannot seem to find them tonight.

Going back to the current consultation, it suggests they probably won't all be built all at once but one after another. In that case I would argue that TfW's current Ebbw Vale and Cheltenham Spa services should start calling at each station (as appropriate; obviously the Cardiff - Ebbw Vale trains won't be able to call at stations east of Newport West) as each is built, but difficult to do this without knowing which pair of tracks will end up carrying these services in future in order to build the platforms in the right places.

 

[Smwrff]

NR aspirations for Cardiff Central also includes switching Intercity services to extended platform 0 and 1, ie the northerly pair of lines, which is in line with new 5 station proposals, and ignoring Burns plans to switch lines

 

[Snow1964]

Going back to the current consultation, it suggests they probably won't all be built all at once but one after another. In that case I would argue that TfW's current Ebbw Vale and Cheltenham Spa services should start calling at each station (as appropriate; obviously the Cardiff - Ebbw Vale trains won't be able to call at stations east of Newport West) as each is built, but difficult to do this without knowing which pair of tracks will end up carrying these services in future in order to build the platforms in the right places.

Looking at consultation, does seem

Cardiff East is one island platform between southern pair of tracks, so will require westbound track slewed further south away from other 3 tracks. Newport West, Somerton are also one island platform. Llanwern appears to have an island but loses 5th track (although another pair of tracks bit further south and footbridge spans these too). However Magor and Undy seems to have platforms on outside of 4 tracks (middle pair unserved).

Also it appears Llanwern is to be a park and ride with secondary 800 space gravel car park for events at Millennium stadium etc (also a normal car park)

 

[Rhydgaled]

NR aspirations for Cardiff Central also includes switching Intercity services to extended platform 0 and 1, ie the northerly pair of lines, which is in line with new 5 station proposals, and ignoring Burns plans to switch lines

Indeed, but the Burns plan to switch lines potentially makes more sense than NR's plan in my view. For example, NR's proposed eastwards extension of platform 0 at Cardiff Central to accept full-length IC services would involve significant demolition of a listed building. This could be avoided if IC services were instead switched to the southern pair of lines (as proposed in the Burns plan) using platforms 3 and 4 and local services used platform 0 instead (although it would place a limit on the length of local services, so if 12-car class 387s are to be used on local services after rugby matches etc. they would have to use SDO for platform 0 or be unable to use that platform on event days). There is further discussion on the Cardiff Central proposals in this other topic.