South Wales 'Metro' updates

[Bletchleyite]

What "standard capacity of street trams"? There is huge variation. The Manchester sets are shorter than a Pacer, while the new Croydon and Edinburgh ones are quite long.

 

[MarkyT]

Wouldn't they also need to be 25 kv AC capable to work through Cardiff Central and its surrounds? And even if there may be a case for 750 v DC on losing speed branches without through routes, would it not be sensible to wire the VoG line at 25 kv AC so it can provide an electric diversionary route when Swansea is eventually wired? Not insurmountable obstacles, if high capacity tram trains could be found to meet the network's needs otherwise, but factors that will need to be considered.

The VoG at 25kV would be nice, but of little use if the mainline to Bridgend and beyond is not also electrified. A bit of 750V on NR infrastructure to Barry would not be implausible and would avoid the new tram train/light metro vehicles needing 25kV capability while still retaining the established cross-Cardiff routes. If desired, the Barry electrification could be specced for future upgrade to 25kV, like Rotherham. In Cardiff Central, the main line side (#0-4) could be 25kV while the valleys (#6-8) could be 750V. DC on the VoG would make the station arrangements easier as there would be no system switching neccessary on any platforms. Anything arriving on 25kV from the east would have to switch to diesel (or other self contained) power to proceed further west, whether along the main line or the VoG.

 

[Solaris]

This thread includes the sensible, realistic and financially grounded all the way to the "flat earth conspiracy theorist" type content...also quite a lot of disinformation and genuine misunderstanding. I think it better to wait for the current procurement to produce a winning bidder and solution for the valleys....any ensuing disagreement and debate can at least be informed by what is on offer. As I have said a lot of people with significant, expertise, experience and resources at their disposal having been exploring all the questions raised here for quite a long time. This is a complex process with a range of objectives to satisfy (which WG did publish for Metro http://gov.wales/topics/transport/public/metro/?lang=en and later in http://gov.wales/docs/det/publications/170922-rail-services-of-the-future-brochure-en.pdf )...the best overall solution (which is affordable and deliverable) is what we need and I suspect is what we will get.

 

[Del1977]

I hadn't seen that document.

'As part of the new rail service, services will be improved across the network including the Metro. The Core Valley Lines will be transformed with faster, more frequent “turn up and go” service.
This will require the use of different vehicles from the Pacers and Sprinters used currently. There will be vehicles more suited to delivering Metro services.'

Translation: These vehicles will be trams.

'Providing adequate toilet facilities through future design of the network'

Translation: Trams don't have toilets, so we'll have to build some new facilities on stations.

'Modern energy efficient trains that are more suitable for the types of journeys passengers make in the Metro area and better trains outside the Core Valley Lines'

Translation: Trams and cascaded DMUs.

 

[Del1977]

I've just had another look at the other document that Solaris linked. Obviously this is a puff/PR piece of literature, but I was struck by one thing:

The journey time improvements they suggest LR can achieve on page 21:

Heads of the Valleys -> Cardiff 10-15 minute journey time savings ( on a journey currently taking about an hour) ... Doesn't that sound somewhat ambitious, even for electric fast acceleration units - taking into account the number of station calls?

 

[Gareth Marston]

This thread includes the sensible, realistic and financially grounded all the way to the "flat earth conspiracy theorist" type content...also quite a lot of disinformation and genuine misunderstanding. I think it better to wait for the current procurement to produce a winning bidder and solution for the valleys....any ensuing disagreement and debate can at least be informed by what is on offer. As I have said a lot of people with significant, expertise, experience and resources at their disposal having been exploring all the questions raised here for quite a long time. This is a complex process with a range of objectives to satisfy (which WG did publish for Metro http://gov.wales/topics/transport/public/metro/?lang=en and later in http://gov.wales/docs/det/publications/170922-rail-services-of-the-future-brochure-en.pdf )...the best overall solution (which is affordable and deliverable) is what we need and I suspect is what we will get.

Another hollow post with straw man arguments Solaris - the boys and girls in hiding are all very clever and will come to best ever ever conclusions as this is what they believe they will do (note not the rest of us). And of course if we all sit and keep stum like good little boys and girls when the concerns emerge after award of contract of course the answer will be "there's nothing we can do as the contract is awarded".

Frightened of scrutiny? You sure seem to be. I note that you have declined my previous offer to PM me with actual evidence of these assertions I can only conclude and share this with fellow Forum members that you cant provide any evidence of this what so ever. If you really are "close" to the decision making as you appear to claim to be then then you should be able to feret away some hard evidence to back your claims. Please leak it to me I will keep you anonymous after all if it really is ...the best overall solution (which is affordable and deliverable) then there's nothing to be worried about.

 

[Gareth Marston]

I've just had another look at the other document that Solaris linked. Obviously this is a puff/PR piece of literature, but I was struck by one thing:

The journey time improvements they suggest LR can achieve on page 21:

Heads of the Valleys -> Cardiff 10-15 minute journey time savings ( on a journey currently taking about an hour) ... Doesn't that sound somewhat ambitious, even for electric fast acceleration units - taking into account the number of station calls?

Its all those tram stops

 

[Del1977]

Another hollow post with straw man arguments Solaris - the boys and girls in hiding are all very clever and will come to best ever ever conclusions as this is what they believe they will do (note not the rest of us). And of course if we all sit and keep stum like good little boys and girls when the concerns emerge after award of contract of course the answer will be "there's nothing we can do as the contract is awarded".

Frightened of scrutiny? You sure seem to be. I note that you have declined my previous offer to PM me with actual evidence of these assertions I can only conclude and share this with fellow Forum members that you cant provide any evidence of this what so ever. If you really are "close" to the decision making as you appear to claim to be then then you should be able to feret away some hard evidence to back your claims. Please leak it to me I will keep you anonymous after all if it really is ...the best overall solution (which is affordable and deliverable) then there's nothing to be worried about.

To be fair to Solaris, if he is internal to this process, then I'm pretty certain that disclosure would be a breach of his NDA and employment contract, so I wouldn't expect him to be providing evidence on a public forum which could be traced back to him.

 

[Solaris]

To be fair to Solaris, if he is internal to this process, then I'm pretty certain that disclosure would be a breach of his NDA and employment contract, so I wouldn't expect him to be providing evidence on a public forum which could be traced back to him.

...or she.

 

[gareth950]

This thread includes the sensible, realistic and financially grounded all the way to the "flat earth conspiracy theorist" type content...also quite a lot of disinformation and genuine misunderstanding. I think it better to wait for the current procurement to produce a winning bidder and solution for the valleys....

Ok then, please point out what the disinformation and misunderstanding posted in this thread actually is.
Are the Impact assessments released by Mott Macdonald disinformation and misunderstanding?
Is the TfW planning application for a tram depot on WG land at Taffs Well disinformation & misunderstanding?
Are assumptions that the current cross city network will be split up misunderstanding?
Are asumptions, based on the Mott Macdonald reports and what we know about how this is politically playing out, regarding the VoG, City lines, Ebbw Vale and Maseteg lines staying 150 DMU operated for the forseeable future misunderstsnding?
Do I think you'll have the nerve to answer any of these Qs other than coming back with more 'don't question us' platitudes? Of course not.

I think it better to wait for the current procurement to produce a winning bidder and solution for the valleys....any ensuing disagreement and debate can at least be informed by what is on offer. As I have said a lot of people with significant, expertise, experience and resources at their disposal having been exploring all the questions raised here for quite a long time. This is a complex process with a range of objectives to satisfy (which WG did publish for Metro http://gov.wales/topics/transport/public/metro/?lang=en and later in http://gov.wales/docs/det/publications/170922-rail-services-of-the-future-brochure-en.pdf )...the best overall solution (which is affordable and deliverable) is what we need and I suspect is what we will get.

Why not release the information before the winning bidder is announced rather than presenting it as a fair accompli in May? In other words, we're not going to listen to the public who actually use the services, businesses, rail users, politicians, we're not going to allow scrutiny of our plans, we know best, you know your place, don't question us.
Any information about the new franchise has come from Grayling and the DfT. WG and Skates have released nothing other than wishy washy 'transformational' platitudes. It's disgraceful.

Network Rail staff who work on the Valleys are in the absurd situation where they still don't know who they will be working for in October, or even if they'll have a job. Many have found out about the LR plans drawn up by MM on FB. Is that acceptable in any way?

How can you not be ashamed of the way Carwyn Jones' govt are treating rail users with total contempt?
In what way is this at all democratically acceptable?
It's Carwyn Jones heavy handed, stifle any opposition or scrutiny, top down approach to government all over. Thank god he's on his way out.

 

[gareth950]

A question for the locals in the thread - would you have been happy with (prefer?) an order of 3-car 23m DMUs such as the CAF ones on order for Northern, but no other service changes other than a bit of peak tweaking to recognise that there could be no multiple working with that length of train? That would be viable, I reckon, and is an approach that seems to have done fine to upgrade the Snow Hill lines out of Birmingham.

3 car 20m, end gang-wayed DMUs to keep the network together and make best use of CASR is a good option.
But WG won't go with it as they want to get one up on Grayling.

 

[Bletchleyite]

I hadn't seen that document.

'As part of the new rail service, services will be improved across the network including the Metro. The Core Valley Lines will be transformed with faster, more frequent “turn up and go” service.
This will require the use of different vehicles from the Pacers and Sprinters used currently. There will be vehicles more suited to delivering Metro services.'

Translation: These vehicles will be trams.

'Providing adequate toilet facilities through future design of the network'

Translation: Trams don't have toilets, so we'll have to build some new facilities on stations.

'Modern energy efficient trains that are more suitable for the types of journeys passengers make in the Metro area and better trains outside the Core Valley Lines'

Translation: Trams and cascaded DMUs.

To be fair, while I think you are right, Class 707s from SWR would also fit the entirety of that.

 

[Bletchleyite]

3 car 20m, end gang-wayed DMUs to keep the network together and make best use of CASR is a good option.
But WG won't go with it as they want to get one up on Grayling.

Or even 4-section bi-mode FLIRTs and a long term drip-fed electrification programme.

 

[gareth950]

I hadn't seen that document.

'Providing adequate toilet facilities through future design of the network'

Translation: Trams don't have toilets, so we'll have to build some new facilities on stations.

That will end up being permanently locked due to vandalism.

 

[B&I]

The VoG at 25kV would be nice, but of little use if the mainline to Bridgend and beyond is not also electrified. A bit of 750V on NR infrastructure to Barry would not be implausible and would avoid the new tram train/light metro vehicles needing 25kV capability while still retaining the established cross-Cardiff routes. If desired, the Barry electrification could be specced for future upgrade to 25kV, like Rotherham. In Cardiff Central, the main line side (#0-4) could be 25kV while the valleys (#6-8) could be 750V. DC on the VoG would make the station arrangements easier as there would be no system switching neccessary on any platforms. Anything arriving on 25kV from the east would have to switch to diesel (or other self contained) power to proceed further west, whether along the main line or the VoG.

But then we're back to the Manchester approach. Why is nothing allowed to be future-proofed? Why would you build something to 750 v DC and then have the expense and hassle of conversion?

And why, when you can have 8 multiple use platforms at Central, would you rule 3 them out of use for electrified trains? Has this even been allowed for in the specification for the electrification at Central?

 

[B&I]

To be fair to Solaris, if he is internal to this process, then I'm pretty certain that disclosure would be a breach of his NDA and employment contract, so I wouldn't expect him to be providing evidence on a public forum which could be traced back to him.

So what is he, she or it (allowing for the possibility of a BayBot) doing on a public discussion forum, trying to stop other people discussing things?

 

[PHILIPE]

So what is he, she or it (allowing for the possibility of a BayBot) doing on a public discussion forum, trying to stop other people discussing things?

I think we should invite Solaris to tell us who he/she is and what relationship if there is, is there with the Welsh Government. otherwise Solaris is as secretive as the Government itself on this issue.

 

[Mr Apples]

I'm a new member but have been following this, and the other W&B-related threads for a while. I am a regular commuter from Lisvane&Thornhill into Cardiff.

From a commuter point of view, I think the existing valley lines timetable is fine, especially now the CASR seems to be working and makes both Cardiff Central and Queen St work much more smoothly. The only problem is, of course, the totally inadequate and elderly pacer units. We just need 3 car end-gangway units that can double up to 6 at peak times (either diesel or electric, new or second-hand, I don't care, just get on with it). I am also strongly in favour of retaining the existing HR cross-city links.

Regarding the 319 / 769 conversions, I hope the much vaunted 'capacity increase' is not going to be accounted for by using 3+2 seating. There are some big people using the service, and if you make the seats narrower, it effectively becomes 2 + 1 seating as people can't fit in the narrower seats. I remember about 7-10 years ago (I think), ATW got some more 150/2 units from Scotland - I believe these had the 3+2 removed in favour of 2+2, and the 150s on the line are generally fine, but evidently dont meet the PRM-TSI regs.

Please don't give us trams - they'll be fine for me, but for commuting from Rhymney, Aberdare etc? Please not!!

 

[Del1977]

I'm a new member but have been following this, and the other W&B-related threads for a while. I am a regular commuter from Lisvane&Thornhill into Cardiff.

From a commuter point of view, I think the existing valley lines timetable is fine, especially now the CASR seems to be working and makes both Cardiff Central and Queen St work much more smoothly. The only problem is, of course, the totally inadequate and elderly pacer units. We just need 3 car end-gangway units that can double up to 6 at peak times (either diesel or electric, new or second-hand, I don't care, just get on with it). I am also strongly in favour of retaining the existing HR cross-city links.

Regarding the 319 / 769 conversions, I hope the much vaunted 'capacity increase' is not going to be accounted for by using 3+2 seating. There are some big people using the service, and if you make the seats narrower, it effectively becomes 2 + 1 seating as people can't fit in the narrower seats. I remember about 7-10 years ago (I think), ATW got some more 150/2 units from Scotland - I believe these had the 3+2 removed in favour of 2+2, and the 150s on the line are generally fine, but evidently dont meet the PRM-TSI regs.

Please don't give us trams - they'll be fine for me, but for commuting from Rhymney, Aberdare etc? Please not!!

Welcome.

I wouldn't get your hopes up on 2+2 seating....

 

[Bletchleyite]

There won't be 3+2 in a tram, a tram is not wide enough.

 

[gareth950]

I wouldn't get your hopes up on 2+2 seating....

No one should get their hopes up on the 769s full stop. They are late to Northern, who are getting them first. It's highly unlikely Wales will get any 769s this year. We are more likely to see Northern's 144s come down to Wales first.

 

[Mr Apples]

No one should get their hopes up on the 769s full stop. They are late to Northern, who are getting them first. It's highly unlikely Wales will get any 769s this year. We are more likely to see Northern's 144s come down to Wales first.

Is that likely to happen? Or just conjecture?

 

[gareth950]

Is that likely to happen? Or just conjecture?

Check out the 769 thread over in the rolling stock section. I don't think they've even gone into production yet.
As for Wales getting more Northern Pacers - it's the only obvious solution that can be thought of to help Wales meet the 2020 deadline. Unless a secret large scale D-train order has been placed, embargoed under the Official Secrets Act.

 

[Gareth Marston]

3 car 20m, end gang-wayed DMUs to keep the network together and make best use of CASR is a good option.
But WG won't go with it as they want to get one up on Grayling.

Providing CAF win the order and build them in Newport there's a opening to spin how great and wise WG has been. The three car versions of the 195's being ordered for Norther Connect have 204 seats I imagine a metro version would be lower with more standing space. So we're talking about the same seats as a 4 car Pacer/ 150 combo albeit with much better standing space.

 

[Gareth Marston]

I think we should invite Solaris to tell us who he/she is and what relationship if there is, is there with the Welsh Government. otherwise Solaris is as secretive as the Government itself on this issue.

We don't want Christian name surname or address. I'm quite happy for forum members to know my credentials so to speak. I own a Station Agency business, I worked for Welsh Government and was involved in the ebbwvale reopening and Welsh Highland Railway funding.Prior to that I have been Chairman of my local RUG and a Public Member of the Rail Passenger Council for Wales. My other half was in British Rail Boards Policy Unit.

 

[Del1977]

We don't want Christian name surname or address. I'm quite happy for forum members to know my credentials so to speak. I own a Station Agency business, I worked for Welsh Government and was involved in the ebbwvale reopening and Welsh Highland Railway funding.Prior to that I have been Chairman of my local RUG and a Public Member of the Rail Passenger Council for Wales. My other half was in British Rail Boards Policy Unit.

Good to see someone providing valuable community facilities at small stations.

I've been on the Ffestiniog Railway during a rail lines tour of North and Mid Wales but managed to miss off the Welsh Highland Railway. Ah - wait. The Welsh Highland Railway probably wasn't open when I did my tour. I'll have to add it to my list of heritage lines to visit at some point.


I don't have any connections with the rail industry, other than a university friend who was at TfL, then DLR (both operations) and is now doing the same in Australia. As for me - I'm a chartered accountant, so I'll expect to hear complaints about 'bean counters'. . My interest in the Valley Lines (and South Wales in general) is because that's where I grew up, but I'm more likely these days to be using the Jubilee line or a Thames Clippers' catamaran.

 

[Gareth Marston]

Let's not turn this into a general confessional but let's see if Solaris who won't post any details publicly or PM me with any evidence to back up their assertions can demonstrate anything that might give credence to their hints of an inside track.

 

[gareth950]

For evidence of how Carwyn Jones' Welsh Govt deals with anyone from within it's ranks who questions the supreme leaders' authority or calls for scrutiny of government policy, look no further than how Jenny Rathbone was 'ruthlessly dealt with' in October 2015 when she spoke out against the M4 relief road:

https://www.walesonline.co.uk/news/politics/sacked-labour-committee-chair-jenny-10253700

Sacked Labour committee chair Jenny Rathbone attacks 'unhealthy culture' at the top of Welsh Government

A Labour AM sacked by Carwyn Jones as a committee chair has launched an attack on the “unhealthy culture” at the top of the Welsh Government, saying anyone who criticises its decisions from within the party group is “ruthlessly dealt with”.

Cardiff Central AM Jenny Rathbone spoke out against the spending of millions of pounds on a controversial M4 relief road route around Newport she believes will never go ahead.

In response, the First Minister sacked her as chair of the committee monitoring the spending of EU aid money in Wales.

'Disappointed no debate has taken place'

Ms Rathbone issued a statement saying: “Following my intervention on the issue of the M4 relief road in the media last week, the First Minister has dismissed me from the role of chair of the All Wales European Programme Monitoring Committee, for speaking out publicly.

“In the Labour group meeting on Tuesday, I reiterated my call for a debate within the group on this massive spending commitment. I am disappointed that no such debate has yet taken place and there is no commitment by the First Minister to allow this to take place at some future date. I remain confident that my views are shared by the majority of Labour AMs, even if they are not encouraged to express them.

“The events of the last 24 hours have confirmed in my mind there is an unhealthy culture at the top of the Welsh Government which does not allow for rigorous debate and reflection on the best use of public funds. Independent thought is not tolerated by AMs and if someone does step out of line, they are ruthlessly dealt with. This is not a good way to make difficult decisions.”

A spokesman for the Welsh Conservatives said: “We all saw the celebrations in North Korea over the weekend. Little did we know we have our very own Kim Jong Un, here in Wales. The First Minister has serious questions to answer over Jenny Rathbone’s claims about the culture at the heart of Welsh Government. Clearly the First Minister is being very poorly advised.”

Plaid Cymru AM Simon Thomas said: “Jenny Rathbone has today shone a light on the way the Welsh Government operates. We already knew this was a government that tried to avoid scrutiny where possible but the Labour AM’s account of top-down decision-making suggests that this is a government that hides from scrutiny and debate.

A senior Welsh Labour source said: “Sadly this has been a long time in coming. Jenny has exhibited limited understanding of how to raise issues with Labour colleagues, and by claiming to speak for others in criticising the Welsh Labour Government, she’s badly let down her colleagues in the Labour Group of AMs.

“It is simply wrong to suggest there’s been no discussion of the M4 in Labour Group, but even so, Jenny has never once tried to raise it as a topic for discussion with the Chair, or the Minister. Hopefully, she will reflect on this and find a better way of debating important issues in the future.” - (Know your place Jenny!)

Also yesterday in the Assembly chamber there was an explosive exchange between Carwyn Jones and Plaid's Adam Price, and Price can be heard shouting "What is this, Putin's Russia? Goodness gracious me".

http://www.bbc.co.uk/news/uk-wales-politics-42887133

I have not posted this to open discussion on the M4, this is not the place. I am highlighting the deeply ingrained culture within this Welsh Govt under Carwyn Jones to avoid any scrutiny of policy, even from within, and how anyone daring to question Jones' authority is dealt with.
It explains a lot about this franchise award process.

 

[NotATrainspott]

No matter how sensible it seems, TfW or the new ODP are not getting control of these lines. Grayling thinks hybrid trains are the solution to electrification and is on record as saying he expects to see it's use in the Cardiff and Valleys areas. He will not authorise NR to electrify these lines.

You've never addressed my point about LUL and NR. The 'core Valley Lines' infrastructure could be devolved and handed over to the private operator, a la Metrolink. Freight services can use the devolved lines just as Chiltern services run on LUL tracks. The devolved passenger services can run on NR-controlled tracks.

If DfT were solely in control of the award of this new franchise and /or the Valley lines, do you think we'd even be having these discussions? Valley lines electrification would have been canned last Summer when Cardiff - Swansea was axed and we'd be getting new DMUs and that would be the end if it. Maybe DOO DMUs but still.

The DfT like cutting subsidy. The only realistic way to cut subsidy is to do light rail conversion. The DfT really isn't interested in looking after LR operations.

It's not just around the corner, it's here now. The upgrades have been paid for and implemented. The signalling is ready. The platforms are ready. The infrastructure in Queen St and Central is ready. We just need the politicians to order the trains.

It's not here now. The 'simple' matter of ordering new trains means committing to extra subsidy in perpetuity.

How much did CASR's improvements cost on top of simple renewals? Renewal projects almost always mean improvements by default, because newer kit is more capable.

Forgive me if I don't quite see the attraction of ripping up 2 electric suburban railways, blocking both in the process to any use for through services (for which one of them was still vital at the time), then putting in some sort of pseudo-heavy rail solution 40+ years later. What is the advantage of some sort of DLR clone over the Metrolink?

The Manchester region, like south Wales, should be allowed to aspire to the world-class public transport seen in most other western European countries, not fobbed off with some low capacity, low quality rubbish because British governments fetishise not spending money. There is a place for light rail, but it is not generally providing an inadequate substitute for heavy rail on heavy rail alignments.

And before you mention Karlsruhe, it's not exactly comparable size-wise to either Manchester or Cardiff. It's also conspicuous in being one of the very few cities anywhere to run light rail vehicles on heavy rail tracks (although at least its scheme doesn't bar those heavy rail tracks to heavy rail vehicles). If converting everything to light rail is such an obviously good idea, why have so few countries done it?

Oh for goodness sake.

Are you really arguing that Metrolink has been a failure? How many expansions and service improvements has it seen? How many improvements have comparable cities seen in the same time? Going for trams has been absolutely key to make the system work. Manchester might be a large city but it simply does not have the density required for an underground metro. British urban planning has ensured that nowhere outside of London really justifies a tunnelled Metro today. Other cities on the continent have comparable populations but they're more densely packed, making the high cost of tunnelling more worthwhile.

What would a DLR do over a Metrolink line? Mostly the ability to run trains longer than 60m, and without having to cross the other tram lines in the city. It doesn't mean 'ripping up' the existing lines at all. A few platform extensions and maybe replacing some level crossings with bridges/underpasses is basically it.

The reality is it will cost more to staff an LRT system than the current one because the Labour administration will not want to be seen anywhere near a decision that sacks well paid workers and reemploys them at cheaper rates. Metrolink managed it back in the early 90's as the pay differential then was not great and BR could absorb those wanting to stay through natural wastage and they were far fewer in number than those potentiality effected in South Wales. The TfW LRT system will be today's wages plus.

Why would wages increase? There will always be natural wastage. New replacements have no claim for HR wage levels.

I've just had another look at the other document that Solaris linked. Obviously this is a puff/PR piece of literature, but I was struck by one thing:

The journey time improvements they suggest LR can achieve on page 21:

Heads of the Valleys -> Cardiff 10-15 minute journey time savings ( on a journey currently taking about an hour) ... Doesn't that sound somewhat ambitious, even for electric fast acceleration units - taking into account the number of station calls?

Have you ever been on a tram running on a dedicated line? You feel real G-forces when they accelerate from a standstill. Complete level access will reduce dwell times. These together make stopping services much, much faster than old or new DMUs could ever manage.

But then we're back to the Manchester approach. Why is nothing allowed to be future-proofed? Why would you build something to 750 v DC and then have the expense and hassle of conversion?

And why, when you can have 8 multiple use platforms at Central, would you rule 3 them out of use for electrified trains? Has this even been allowed for in the specification for the electrification at Central?

In Rotherham the 750V DC wiring on the NR tracks uses the same masts as 25kV AC. On sections with a very high probability of being converted soon, you can install all of the metalwork and wiring needed by 25kV and run 750V DC through it. On less probable sections, it could be tram catenary strung from the HR masts.

25kV AC dual-voltage capability is absolutely trivial to add to new-build metro vehicles. Let NR wire up Cardiff how they want and then add in 750V DC for the bits they don't have to cover but the Metro would need.

 

[MarkyT]

25kV AC dual-voltage capability is absolutely trivial to add to new-build metro vehicles. Let NR wire up Cardiff how they want and then add in 750V DC for the bits they don't have to cover but the Metro would need.

Perhaps not entirely trivial, but as long as it's designed in from the outset, multisystem electrical compatibility is technically straightforward today and has been incorporated in most tram-train designs to date for example. New MerseyRail and T&W replacement stock, also both 'light metro' in character, will be convertible in this way. The step-down transformers themselves need not be installed immediately, but there will be space reserved for them on board and their weight will be is taken into account. When the first segment of 25kV running is required at some time in the future, for an extension or a system conversion, an appropriate proportion of the fleet can be modified accordingly, quickly at the depot.