As noted previously, the Welsh Assembly Government (WAG) is proposing a Cardiff & Newport metro and are running a franchise competition to select an ‘Operator and Development Partner’ (ODP) for the Wales & Borders franchise. The first part of this post pointed out that the late and over-budget partial redouble of the Wrexham-Chester line has led WAG to adopt a risky strategy; taking ownership of the ValleyLines infrastructure north from Cardiff Queen Street, plus the Cardiff Bay branch and maybe the Cardiff Central to Cardiff Queen Street section, off Network Rail.
One of the risks is the very fact that it is an untried approach; to my knowledge a significant portion of the national network has never been split off since the big four were merged to create British Railways. Sections have of course been sold off to create heritage railways, but they are their own self-contained operations and the Cardiff Metro will have to maintain interfaces with Network Rail, if only for freight services. Admittedly some heritage railways have ambitions to extend their services onto Network Rail infrastructure, but so far I believe only the North Yorkshire Moors Railway has achieved this. So, the second risk is that Network Rail isn’t completely removed from the picture. That in turn gives rise to a third risk; that WAG and/or their ODP may try to minimise the interfaces with Network Rail by segregating what WAG are already calling ‘the core ValleyLines’ to a very great extent.
At present of course, many services from north of Cardiff (Aberdare, Merthyr Tydfil and Rhymney) run through to Penarth, Barry Island and the Vale Of Glamorgan Line to Bridgend. That is very sensible, since a frequent service runs Cardiff Central on these routes; and this is unlikely to decrease. A potential Metro frequency of 4tph (trains per hour) from each of Treherbert, Aberdare, Merthyr Tydfil, Rhymney, Penarth and Barry Island, plus 2tph from Bridgend via the Vale Of Glamorgan is a total of 26tph before considering Coryton and Radyr services. Even with four platforms (4, 6, 7 and 8) now nominally designated as ‘ValleyLines’ platforms, 26tph terminating at Cardiff Central would give less than nine and a half minutes for turn-around time. Add Coryton, Radyr and possible new lines and recovering the timetable following delays would be well-nigh impossible. Trying to split core ValleyLines services from the rest of the Cardiff Metro would therefore be a serious risk to punctuality.
Splitting the service also presents a risk of a different kind; a risk to passenger comfort. While the current fleet of class 150s and Pacers is not-exactly comfortable, there’s worse out there. The one thing less comfortable than a seat on a Pacer is having to stand; and one option the Welsh Government may be considering could reduce the availability of seats. That option is light-rail, probably in the form of trams. The Bombardier M5000 trams on Manchester’s Metrolink are about the same length as a Pacer but have 46 fewer seats (almost halving the 106 seats on a Pacer) and room for perhaps 100 more standing passengers. Any other passenger train will be longer than a Pacer, and hence have even more room for seats. Even if you have longer trams than Manchester’s, each coach still needs to be shorter than most train carriages because trams need to handle tighter curves. Shorter carriages mean more corridor connections between cars and probably more doors, leaving less room for seats. Light-rail would probably make the project cheaper, and perhaps enable earlier delivery, but with a journey from Cardiff to Merthyr Tydfil taking an hour (perhaps slightly less with electrification) I don’t think it is the right choice.
A further risk is that budget overruns and project delays aren’t unique to Network Rail projects anyway. WAG and their ODP will probably need to choose from the same pool of electrification contractors as Network Rail, and so they may yet suffer similar high costs and late delivery.
Returning to the idea of trams; despite the reduced seating capacity which I deem unacceptable for the longer journeys, there are clear benefits. Perhaps the most important is that trains cannot mix with road traffic on street-running sections. That means a direct rail service between Cardiff Central and Cardiff Bay, which seems to be a key Welsh Government objective, is probably only possible with trams (which I suppose would stop at street-level outside Cardiff Central’s new southern entrance). The reduced cost of lower-voltage light-rail electrification, as already mentioned, is also plus so maybe a mix of tram and train could be the optimum outcome for the Cardiff Metro.
Limiting light-rail to the shorter routes however poses a number of problems. The Cardiff Bay line is the only obvious candidate for light-rail conversion, with short on-street links at both ends (to Cardiff Central at the north end and closer to the millennium centre etc. at the other end). That alone seems unlikely to provide either the volume necessary to justify the overheads of a tram system (such as a depot) or access to an area of open land for a depot. Ordinary trams might be permitted to share streets with cars, but they are not allowed to share tracks with heavily-built national rail trains, so the rumoured Metro depot location at Taff’s Well is out of reach. Tram-trains could run everywhere, but are more expensive than straight trams and the UK’s tram-train pilot scheme in Sheffield is behind schedule. With the possible removal of funding if the project isn’t complete by 2023, the tram-train option might also be a big gamble.
Let us assume therefore that it is a choice between having some trams that cannot run on heavy-rail tracks and not being able to deliver the Cardiff Central – Cardiff Bay link. How do you grow the tram network enough to reach a suitable depot location, without either blowing the budget or screwing up the heavy-rail part of the Metro by converting more of the existing network? Taff’s Well is 20 minutes from Cardiff Central, right on the limit of being too far to subject passengers to the loss of seats that trams would bring. However, it is over 5 miles as the crow flies; I doubt finding and constructing an all-new route from Cardiff is feasible, so existing rail alignments would need to be used. That either means quadrupling (providing two light-rail tracks and two-heavy rail ones) or conversion to light-rail. As far as I can tell from Google Earth, there is no room for more tracks on some sections that would need quadrupling. That means a conversion would be necessary, but since any services north of Taff’s Well and Llanishen ought to remain heavy-rail the Cardiff Queen Street to Heath cannot be converted and heavy-rail services and the same applies to at least one of the two routes to Radyr (via Fairwater and via Cathays).
Therefore, there are two final questions.
- whether a single double-track route for services from north of Taff’s Well to Cardiff is sufficient and, if not
- whether it is possible to build a street-running tram route of almost 4 miles from Cardiff Central to Heath, plus 2.5 and a bit miles of new line from Coryton into Taff’s Well
Making the metro is not going to be easy.