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.
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.
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.
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.
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.