South Wales 'Metro' updates

[cloakanddagger]

Network Rail have submitted the full business case for upgrading the relief lines on the south Wales main line: https://www.networkrailmediacentre....submitted-to-help-unlock-new-railway-stations

The proposals, submitted to the UK Government Department for Transport, include infrastructure improvements across 27 miles of track, with refurbishment and renewal works, as well as increasing speeds on the Up and Down relief lines from 40mph to up to 100mph, where feasible.

Subject to full business case approval, this work will allow for future increased line speeds on the relief lines that run alongside the main lines between Cardiff Central and Severn Tunnel Junction. While these lines are currently used primarily by freight services, the improvements would enable them to accommodate passenger services, without adding time to journeys, creating additional capacity and improved reliability and performance across this vital section of railway. The work will also allow freight trains to run faster, improving overall network efficiency.

 

[AdamWW]

I've just seen that the trains that just run between Pontypridd and Cardiff Bay (not the route itself) will be suspended for two months from Sunday 22nd March (though in fact I think nothing is running on the 22nd).
This is "to support the introduction of the first tram-trains later this spring".

Presumably this frees up the paths to run 398s in non passenger service, though I presume it may end up that some of the time nothing runs in them.
(And for what it's worth I can't see anything in Realtimetrains for them on Monday).

On the upside the Bay will still get four trains an hour, running entirely as a shuttle as in the old days, though still in the same current irregular pattern.

These services are the ones that some people need to change onto to avoid significantly longer journey times now that the Aberdare trains go round the City Line (worst case and I suspect not a common journey but nevertheless) Aberdare to Cathays I think takes an extra half hour without them.

Today is the first I've heard of this - does anyone know when it was announced? I'd have thought a fair bit of notice would be useful for anyone who may have wanted for example, to change their season ticket and drive to a different station for the duration (or indeed the whole way).

[Edited for clarity]

 

[Bob Price]

I've just seen that the Pontypridd to Cardiff Bay service will be suspended for two months from Sunday 22nd March (though in fact I think nothing is running on the 22nd).
This is "to support the introduction of the first tram-trains later this spring".
Presumably this frees up the paths to run 398s in non passenger service, though I presume it may end up that some of the time nothing runs in them.
(And for what it's worth I can't see anything in Realtimetrains for them on Monday).

On the up side the Bay will still get four trains an hour, running entirely as a shuttle as in the old days, though still in the same current irregular pattern.

These services are the ones that some people need to change onto to avoid significantly longer journey times now that the Aberdare trains go round the City Line (worst case and I suspect not a common journey but nevertheless) Aberdare to Cathays I think takes an extra half hour without them.

Today is the first I've heard of this - does anyone know when it was announced? I'd have thought a fair bit of notice would be useful for anyone who may have wanted for example, to change their season ticket and drive to a different station for the duration (or ndeed the whole way).

According to the TfW website it's just late night 21st and all day 22nd. From the TfW site:

Rail improvement works | Transport for Wales

Transport for Wales | Buy Cheap Train Tickets and Check Train Times

tfw.wales

"Buses replace trains between Cardiff Bay / Cardiff Central and Radyr / Caerphilly via Cardiff Queen Street from 23:30 on Saturday 21 and all day Sunday 22 March"

 

[John R]

According to the TfW website it's just late night 21st and all day 22nd. From the TfW site:
"Buses replace trains between Cardiff Bay / Cardiff Central and Radyr / Caerphilly via Cardiff Queen Street from 23:30 on Saturday 21 and all day Sunday 22 March"

Train disruption | Rail works | Transport for Wales https://share.google/ON6ajG6BdtUfwi1Og

Presumably it’s for when somebody flicks a big switch and hopes nothing goes bang in the Bay?

 

[AdamWW]

According to the TfW website it's just late night 21st and all day 22nd. From the TfW site:
"Buses replace trains between Cardiff Bay / Cardiff Central and Radyr / Caerphilly via Cardiff Queen Street from 23:30 on Saturday 21 and all day Sunday 22 March"

I think we're at cross purposes here.

Yes there is a line closure on Sunday.

But after that for two months the Pontypridd to Cardiff Bay services will only run between Cardiff Bay and Cardiff Queen Street.

I have looked on their web site and can't see anything about it on their appalling services changes page, but it comes up as a "service alert" if you use the journey planner then ask for "live times" on journeys to the Bay.

Service alert
From Sunday 22 March until Friday 22 May, the half-hourly Pontypridd to Cardiff Bay service will not run. This is to support the introduction of the first tram-trains later this spring. Please use other services and change at Cardiff Queen Street to connect with the Cardiff Bay shuttle service (four trains per hour during this period) that runs from platform 1.

 

[VR494]

That's good! It certainly looks ready to open again.

It’s most definitely down to open in April.

Then it will interesting to see how the additional stop affects the timetable.

 

[AdamWW]

It’s most definitely down to open in April.

Then it will interesting to see how the additional stop affects the timetable.

Yes I've been wondering about that.

They don't seem to arrive much before the timetabled time at Heath when heading south.

On the other hand 150s don't seem to either and they used to cope.

So maybe it will be OK.

 

[Bob Price]

I think we're at cross purposes here.

Yes there is a line closure on Sunday.

But after that for two months the Pontypridd to Cardiff Bay services will only run between Cardiff Bay and Cardiff Queen Street.

I have looked on their web site and can't see anything about it on their appalling services changes page, but it comes up as a "service alert" if you use the journey planner then ask for "live times" on journeys to the Bay.

Yes we are. I thought you meant it's was a total shut down. With you now.

 

[Smwrff]

Interesting that the map they have shows it running south of the eastern link road despite the current freight line running to the north of the road.

Anyway this is getting into speculation territory so probably best future discussion on that part of cross rail goes into the other thread.

With the electrification of the rhymney line being approved by the ORR is there any sign of it being used for passenger services yet?

In the Atlantic Quay (new arena) Masterplan it clearly shows the tram alignment south of new Pierhead station heading towards north side of Roath Dock - ie to south of Eastern Bay Link Road - presumably to pick up the freight line near Ocean Way roundabout.

 

[Snow1964]

Formal announcement of completion of electrification

23 Mar 2026​

Transport for Wales has completed the full electrification of the Core Valley lines, at the heart of the South Wales Metro, delivering one of Wales' most ambitious rail infrastructure transport projects.

The Overhead Line Equipment (OLE) on the final 800 metre section between Cardiff Queen Street and Cardiff Bay has now been completed and tested as TfW prepares for the full electrification of the 170km network, completing a six-year transformation programme that began in 2020.

Dubbed the ‘Welsh Tube’, the £1bn project brought electric tri-mode trains to the South Wales Valleys for the very first time in 2024. This spring, TfW will introduce the first of its 36 fully electric Class 398 tram-trains. The new fleet will initially operate between Pontypridd and Cardiff Bay, providing greener, more frequent services as part of the South Wales Metro.

Passengers are already benefitting from these improvements with the Core Valley lines being one of the most punctual and reliable networks in Great Britain over the past 6 months.

Since work began in 2020, TfW and its partners have delivered an intensive programme of specialist engineering which includes:

• 281.5 miles of overhead wires installed
• Over 3,100 steel posts and 8,200 small steel parts installed to hold the wires in place.
• 14 railway track lowers completed to install wires under bridges.
• Five substations installed.
• Extensive vegetation clearance and fencing renewals to keep the network safe from trespass.

Working closely with partners Amey Infrastructure Wales, TfW introduced a world-leading Smart Electrification System that combines wired and wire-free sections made possible by innovative tri and bi-mode trains, capable of switching seamlessly between overhead electric power and battery.

The approach has delivered carbon and cost reductions compared with traditional fully wired systems, while avoiding the need for lengthy and disruptive bridge closures.

100% electrification of the Core Valley Lines complete

Transport for Wales has completed the full electrification of the Core Valley lines, at the heart of the South Wales Metro, delivering one of Wales' most ambitious rail infrastructure transport projects.

news.tfw.wales

So presumably they now disperse the teams, lose the accumulated experience, find it slow or difficult (and expensive) to restart due to lack of rolling programme

 

[AdamWW]

Formal announcement of completion of electrification

Interesting that they've been lowering track under bridges - I wasn't aware of that.

I would have thought that would be the sort of thing that discontinous (sorry - "smart") electrification would remove the need for.

 

[John R]

Interesting that they've been lowering track under bridges - I wasn't aware of that.

I would have thought that would be the sort of thing that discontinous (sorry - "smart") electrification would remove the need for.

I think the system as delivered already has a large number of discontinuities, (neutral sections under bridges as well as those sections with no wires) so presumably a line had to be drawn as to how many were feasible.

 

[The exile]

Interesting that they've been lowering track under bridges - I wasn't aware of that.

I would have thought that would be the sort of thing that discontinous (sorry - "smart") electrification would remove the need for.

Presumably if you’re doing major track renewal anyway, lowering track under bridges (where there aren’t other complications such as platforms) is much cheaper than raising bridges would be.

 

[Snow1964]

I think the system as delivered already has a large number of discontinuities, (neutral sections under bridges as well as those sections with no wires) so presumably a line had to be drawn as to how many were feasible.

It was also designed as a Cardiff centric metro system, not really designed for late 2020s BEMUs (the type now being considered by other operators) to extend further and cover some middle distance (say 50 miles) services from Cardiff

As examples, would probably have also done Severn Tunnel Junction -Chepstow (so could use BEMUs to Gloucester / Cheltenham, or Cardiff Queen Street - Barry or Pencoed - Baglan too. Allowing BEMUs to serve more stations Instead using pure diesel 197 trains (of which arguably don't now have enough due to growth). Do have to wonder if few extra bits of electrification and getting fleet of BEMUs for Cardiff outer routes would now be better based on recent growth.

 

[zwk500]

Interesting that they've been lowering track under bridges - I wasn't aware of that.

I would have thought that would be the sort of thing that discontinous (sorry - "smart") electrification would remove the need for.

Discontinuous electrification has been used where it wasn't viable to install OLE. If it was a relatively simple track lower, it's better not to have the pan going up and down like a yo-yo, as it saves wear on both pan and wire, and removes the risk of the pan not being lowered in time.

 

[AdamWW]

Discontinuous electrification has been used where it wasn't viable to install OLE. If it was a relatively simple track lower, it's better not to have the pan going up and down like a yo-yo, as it saves wear on both pan and wire, and removes the risk of the pan not being lowered in time.

Low bridges have been dealt with by installing permanently earthed sections under them, not a physical gap in the wires.
The pantograph stays up throughout.
I don't believe there's anywhere that pans are dropped just to go under a bridge and then raised again straight away.

And in fact in some cases surge protection has been used to allow extremely small clearances to live wires by traditional standards.

Presumably if you’re doing major track renewal anyway, lowering track under bridges (where there aren’t other complications such as platforms) is much cheaper than raising bridges would be.

I'm sure it's an awful lot cheaper than raising a bridge, but it isn't so clear to me that it's cheaper than a permamently earthed section or using surge protection.
I don't know how many bridges have been raised as part of this work but I don't think it's many.

Presumably though once you've lowered track there are reduced maintenance costs compared to the other options, unless it messes up drainage.

 

[TT-ONR-NRN]

The "Welsh tube" is generous. I don't know any Tube lines that have a 1tp2h Sunday service. Especially not to an airport.

 

[positron]

It was also designed as a Cardiff centric metro system, not really designed for late 2020s BEMUs (the type now being considered by other operators) to extend further and cover some middle distance (say 50 miles) services from Cardiff

As examples, would probably have also done Severn Tunnel Junction -Chepstow (so could use BEMUs to Gloucester / Cheltenham, or Cardiff Queen Street - Barry or Pencoed - Baglan too. Allowing BEMUs to serve more stations Instead using pure diesel 197 trains (of which arguably don't now have enough due to growth). Do have to wonder if few extra bits of electrification and getting fleet of BEMUs for Cardiff outer routes would now be better based on recent growth.

Well it's 231s planned on non-core valleys and they're DEMUs so anything is possible with enough money. No real need to buy new trains.

== Doublepost prevention - post automatically merged: 23 Mar 2026 ==

Interesting that they've been lowering track under bridges - I wasn't aware of that.

I would have thought that would be the sort of thing that discontinous (sorry - "smart") electrification would remove the need for.

I suspect it's just based on which tracks they could lower without flood risks, and how many gaps they could fit into their modeling. I think the discontinuous is a replacement for bridge *lifts*, not a replacement for all interventions.

== Doublepost prevention - post automatically merged: 23 Mar 2026 ==

So presumably they now disperse the teams, lose the accumulated experience, find it slow or difficult (and expensive) to restart due to lack of rolling programme

Very likely the case unfortunately, the UK is terrible at maintaining skills. Even if they got short wins like partial electrification to cogan, they're unlikely to get any proper work.

Given the 231s and 197s there's no urgent need for electrification that TfW would be able to do.

 

[takno]

The "Welsh tube" is generous. I don't know any Tube lines that have a 1tp2h Sunday service. Especially not to an airport.

It's better than the current Sunday service on the Piccadilly Line

 

[AdamWW]

I suspect it's just based on which tracks they could lower without flood risks, and how many gaps they could fit into their modeling. I think the discontinuous is a replacement for bridge *lifts*, not a replacement for all interventions.

Fair point though it does go way beyond just avoiding having to raise bridges, for example not electrifying Caerphilly tunnel or Queen Street station.
Or the infrastructure that's still owned by Network Rail.

 

[Markdvdman]

Well the first train from Merthyr at 6:09am past two days not good - a 150 yesterday, rammed well before Cardiff, and a 3 car 756 this am, rammed more than the usual 4 car 756 almost always now! I wonder what is going on, the 5:30pm from Cardiff Central was a 231 yesterday too. Is there an issue with 756s at the moment?

 

[Cardiff123]

TfW were very clever with the wording of the press release of the completion of electrification of 100% of the CVL on Monday. The headline made it sound like the entire network is now fully electrified, but the notes to editors at the bottom states:

2026: Cardiff Bay section tested in preparation for 100% electrification of the CVL network.

So is Cardiff Bay still not yet live?

100% electrification of the Core Valley Lines complete

Transport for Wales has completed the full electrification of the Core Valley lines, at the heart of the South Wales Metro, delivering one of Wales' most ambitious rail infrastructure transport projects.

news.tfw.wales

 

[positron]

I suspect they planned the press release, and decided to go ahead with it anyway even if the go live hasn't happened, so they did a bit of semantic evasion and pressed publish.

== Doublepost prevention - post automatically merged: 25 Mar 2026 ==

Probably want to get as many nice announcements out before the 7th Aprilm

 

[VR494]

TfW were very clever with the wording of the press release of the completion of electrification of 100% of the CVL on Monday. The headline made it sound like the entire network is now fully electrified, but the notes to editors at the bottom states:

So is Cardiff Bay still not yet live?

100% electrification of the Core Valley Lines complete

Transport for Wales has completed the full electrification of the Core Valley lines, at the heart of the South Wales Metro, delivering one of Wales' most ambitious rail infrastructure transport projects.

news.tfw.wales

Without going into detail, the wires should be considered live at all times, even though trains aren’t using them, there are still tests being conducted. But, the line is simply not ready, and needs a lot of work to get it up to the required specifications. Compare the same length of track to projects in other countries, and it’s a complete and utter shambles. There’s no excuse why they couldn’t have finished the project.

But, as like other things, it is running on a limited budget, which also has to fund variable costs throughout. The reality of a devolved infrastructure system.

The Welsh government are expecting a massive miracle, the metro is years behind in reality where they are marketing it. They can post as much content as they like about 4ph and new trains, it’s not happening in their term.

800 million was not spent on the metro either, the majority of that cost went on the 197’s. The CVL was done on the cheapest option possible, and it’s hurting them more now because the 398’s aren’t compatible out of the box. Also buying the units and then going onto online forums for help from the community to get them into service. That’s what they have been doing. The team running the integration process just don’t have the knowledge.

With a bit of luck a new government will focus investment where it’s needed most, not on more vanity projects before they have even finished what they have started.

 

[positron]

I find the track alignment at the bay very weird right now. I'm shocked they haven't tried to get it to a more final state yet. There's a signal (I think?) right in the middle of where the new upline will be at Butetown station. Then there's all the half done downline at the top of the branch that I would have expected them to run down to the Butetown station by now.

Given the station isn't being used either way it seems weird that they didn't finish the new upline and then include the bit of track to get it into platform 2 right at the bottom.

Like you say it feels like the bay line alone is still a lot of work away from finishing let alone the other stuff required for 4tph.

 

[CapitalStar378]

Without going into detail, the wires should be considered live at all times, even though trains aren’t using them, there are still tests being conducted. But, the line is simply not ready, and needs a lot of work to get it up to the required specifications. Compare the same length of track to projects in other countries, and it’s a complete and utter shambles. There’s no excuse why they couldn’t have finished the project.

But, as like other things, it is running on a limited budget, which also has to fund variable costs throughout. The reality of a devolved infrastructure system.

The Welsh government are expecting a massive miracle, the metro is years behind in reality where they are marketing it. They can post as much content as they like about 4ph and new trains, it’s not happening in their term.

800 million was not spent on the metro either, the majority of that cost went on the 197’s. The CVL was done on the cheapest option possible, and it’s hurting them more now because the 398’s aren’t compatible out of the box. Also buying the units and then going onto online forums for help from the community to get them into service. That’s what they have been doing. The team running the integration process just don’t have the knowledge.

With a bit of luck a new government will focus investment where it’s needed most, not on more vanity projects before they have even finished what they have started.

Do you mean the Stadler teams are using online forums or TfW staff? Stadler should be the ones sorting the issues and would have good knowledge surely?

 

[VR494]

Do you mean the Stadler teams are using online forums or TfW staff? Stadler should be the ones sorting the issues and would have good knowledge surely?

The 398 integration team has been using online forums and UK TRAM for help and support. They only started seeking help in 2023. Tfw are a heavy rail organisation and have branched out for advice on how to set up the tram-train. The issue is there are no other UK models that want a train to be a tram, only Sheffield, but their setup and policies are the opposite. Manchester is pure light rail, so there's no point even comparing it to that. The Oldham loop line was a pure conversion.

Currently, there is no realistic plan on how the tram will be integrated or how it will work in combination with the heavy rail – this is all still to be designed. It's a vision, a big jigsaw that won't join and very political.

The CVL OLE infrastructure has been designed around the 756 units, and Stadler have changed loads of software to work with them.

It's also worth noting that Amey has gone through multiple CVL project managers in the process.

UKTram support reflected in major milestone for South Wales Metro as King Charles opens new depot

The official opening of the new South Wales Metro Depot at Taff’s Well marks a significant step forward for Transport for Wales (TfW) and a proud moment for the wider light rail sector. His Majesty King Charles’ visit drew national attention and the milestone reflects years of knowledge exchange...

www.uktram.org

 

[WelshBluebird]

I do question the need to send valley lines passengers to Queen Street on an event day where theres basically no valleys passengers beyond a normal Saturday. You could easily walk around and into the rear entrance of central today with no need for any queuing for those lines.

I absolutely get it for Wales games and other events that are likely to have an interest to those in the valleys, but Bristol v Quinns is not one of those events - 99% of the passengers will be from Bristol, London and the general south of England. There needs to be some nuance because having the queen street system in place today is just wasting people's time.

 

[positron]

The south entrance to central is presumably going to be closed for a quite a while, while they do the enhancements and crossrail works. So I think that's the main reasoning.

 

[MikePJ]

Despite announcements that the Cardiff Bay - Pontypridd services were due to be suspended from 22nd March, they do seem to be running after all, presumably because the electrification delay on the Bay line means they can't run any 398s.