There have been a few proposals for a major redevelopment of Cardiff Central over the last decade or so - at least one of those had all the platform buildings and canopies swept away presumably along the lines of the Reading 'transfer deck' footbridge. Personally, I think all of those redevelopment proposals were horrific acts of brazen vandalism. If Network Rail think they can do that sort of thing to a Grade II listed building then what is the point of having Grade II listing?
I think it is important to note that the reason for listing Cardiff Central was its completeness - the big picture with the platform structures, the main booking hall building on the north side and the main passenger subway (the one with stairs up to the platforms) all work together to provide an extensive example of a big-4-era city centre main station. Take platform 8 and the OHLE away and it could almost be on a heritage railway. Demolish any part of those three main features and you lose the special cohesiveness that the listing was intended to protect.
Unfortunately Network Rail seems to want to make platform 0 the main platform for eastbound fast passenger services, which means extending it to accomodate a pair of class 800s (which I think are around 260m). As far as I can tell from Google Earth, there appears to be space to extend it to around 200m before you have to demolish most of the main booking hall building on the north side (probably including the clock tower on top, which appeared to be gone in at least one set of redevelopment proposals). There is, I suggest, little point in getting a 260m platform zero at Cardiff Central. Either you make a mockery of the listing by resorting to extensive demolition or you would have to move almost the entire station to an open air museum such as the St Fagans National Museum of History*. Either way, you would no longer be constrained by the tiles in the subway and could renumber the platforms at the new Cardiff Central to your heart's content.
* yes, I expect moving the vast majority of a major station is a much bigger challange than anything else that has ever been moved in such a way though, and thus is likely to be impractical.
The only alternative I can see is to talk Network Rail into dropping their plans to move the stoppers onto the present releif lines and instead move fast services onto the releifs (which I guess they would share with freight, due to the terminals being on the south side) - probably as far as Maindee triangle, Newport, where the Marches line joins the GWML. The platforms at the new stations at Cardiff Parkway, Newport West etc. would then have to be built on the current Up Main and Down Main (which I guess would then become the Up Metro and Down Metro). This would mean platform 0 no longer having to accomodate class 800/802 units**. The question is; would you get away with a 200 metre platform 0 for the local services? For much of the year it'd probably be fine, but what about a 12-car class 387 lashup after a major event at the Principality Stadium?
** except during disruption when, with selective door operation and appropriate postioning of signals and 'IET STOP' boards, you would probably wouldn't have to lock out many doors on a 9-car set anyway.
Unfortunately the GWML drops to two tracks west of Cardiff, without the benefit of the relief lines further east, so you run into a 'mixed traffic railway' problem with fast, stopping and freight services tripping each other up. (This is actually an issue further east as well, due in part to the heritage value of the station buildings at Cardiff Central as described above. My 'gut feeling' is that fast trains want their own dedicated pair of tracks and stoppers and freights could share, but Ebbw Vale and Hereford (where some of the stoppers (may in future) branch off are on the north side and the freight terminals on the south. So is it actually better for freights and fast passenger trains to share the southern tracks and stoppers to have the nothern pair to themselves?) The line between Cardiff and Bridgend can't take much more without flighting of fast and slow services (or some form of overtaking provision), whereas what you'd want heading west out of Cardiff*** is something more like this:
- a fast service to Swansea (calling only at Bridgend, Port Talbot and Neath) either every 30 minutes or every 20 minutes
- a train calling at Pyle every 30 minutes, at least one being all-stations to Swansea (including Pontyclun etc.) - the other could be:
- a second all-stations to Swansea,
- an all-stations to Ammanford (or beyond) via the Swansea District Line with Swansea Metro stations
- an all-stations via the Swansea District as above, but to Llanelli instead of Ammanford or
- a semi-fast calling only at Bridgend, Pyle, Port Talbot and Neath
- a train calling at all-stations between Cardiff and Bridgend every 30, 20 or 15 minutes
- at least one of these per hour would run to Maesteg and another would be the above Swansea stopper
- an hourly path reserved for a future express service to Carmarthen/Milford Haven / Fishguard Harbour if/when TfW has some rolling stock available that is optimised for such use (before anyone says otherwise, 197s are not optimised rolling stock for any 'express' or 'fast' service)
*** ignorning freight, as I've no idea how much there is
I fear the only way to increase both fast and stopping services between Cardiff and Bridgend is to either provide some 4-tracking or allow the stoppers to be looped at one of the stations for fasts to overtake. I don't think the current layout at Pencoed, Llanharan or Pontyclun would make this easy, so possibly any progress with frequency enhancements on this stretch will have to wait until Miskin station is delivered (and please make sure that is built with platform loops).
First class and LHCS has nothing to do with it, it's the terminating of services that used to run through that's the problem. When mark 4s to Manchester were first announced it sounded like they would all run through to Swansea (meaning the LHCS would have only been every three hours instead of every two hours) which would have been fine. If mark 4s to Manchester hadn't been a side-effect of COVID but were planned at the time of franchise renewal, TfW could have taken more sets (quite a few have been scrapped) and run LHCS through between Manchester and Swansea every two hours, maybe even hourly. Another alternative might be to terminate all the Manchesters at Cardiff and have GWR run Swansea-Paddington every 30 minutes all day instead.
That option 4 above for the 2nd Pyle stop each hour is a hangover from my old idea for reconfiguring some of the GWR services around Bristol. The old Cardiff-Taunton would have become a Gloucester-Taunton stopper using class 166/165 units (since it runs via Weston-Super-Mare, other services would be much faster to Taunton) and TfW would pick up the Bristol-Cardiff leg which would then extend to Swansea as that semi-fast through Pyle. Cardiff-Portsmouth I would leave largely as it is (assuming it is still hourly and hasn't suffered from the DfT cuts), but switch the stock for 175s (in 5-car formations) and maybe drop some stops onto MetroWest stoppers.
Why was the bay numbered platform 5 (and was it at the east or west end - I thought I'd seen some suggestions to reinstate it for services to Carmarthen)? I would have thought the current platform 4 would originally have been 5 with the bay being 4 instead. Also, with the heavy industry in retreat (and coal almost gone) are two through roads still needed? If not then, as much as I'd rather keep the heritage structures on the majority of the station, if we are to have a massive rebuild perhaps it should go down to one bi-directional through road with the platform 3/4 island being widened to take 4 new bays (2 at each end, like a double-ended version of the main island at Shrewsbury):
===0b===========0a===
===1a===========1b===
===2b===========2a===
=====through road=======
===3a===========3b===
===bay===| |===bay===
===bay===| |===bay===
===4b===========4a===
The tram-train platform for the bay, yes. Personally I think there should also be one or two tram platforms (or passive provision for them) down there on Penarth Road behind platform 8, at roughly 90 degress to the mainline platforms above. This would be for a future tram extension along Penarth Road, under the main station's eastern throat tracks and on-street at least to the Castle and hopefully right through to Heath Low Level (and thence the Coryton line - there's not enough capacity on the existing lines through Queen Street to deliver a Metro frequency on the Coryton line).
