On seating: Making direct comparisons on the availability of seats between new units and say 150sx2 without also having an idea as to relative frequencies of the services isn't really possible.
Only partly true. We have seen with XC what happens if you increase frequency but reduce capacity per service. Really what the valley lines need is an increase in frequency and an increase in capacity. Heavy rail with electrification can easily provide both. Light rail can provide one, maybe half of the other at a push.
On toilets: The same argument could be advanced for the new tram Valley Lines as you've argued for London Underground: Go to the toilet at CDF/CQS (many in the central area), then go to the toilet in Caerphilly/Pontypridd/Merthyr (building if necessary) (representing larger non-central tube hubs). Many of the toilets in the outer fringes of the Underground aren't even open late at night - as I know from experience. My local Underground station now is Canada Water. It doesn't even have a public toilet, though handles millions of passengers a year.
Saying they aren't 'used to it', London is: I'd rather get used to crossing my legs and having a frequent service, than the option of going to the toilet on an hourly Pacer to the fringes! I've never used a train toilet on a Valley Lines train - the journeys just aren't that long - and I'd hope would be quicker as light rail.
I can probably just about let this pass. I don't agree (especially with the "journeys just aren't that long" comment), but it is a fairly small issue compared to the other things. How the travelling public will see this though - I can't imagine they will be happy getting a downgrade! The comment about London was more that, as far as I am aware, the underground hasn't had toilets on board services in recent history, so it isn't there to be missed!
On interchange: I don't see it as a deal breaker if say my tram from Pontypridd rolls into and terminates at CQS and there's a tram just arriving on the adjacent platform from Rhymney going through to CDF. Not if it's frequent. Again, people don't get on tube lines in London and expect to reach their destination without changing. Agree that it's less optimal than them all running through, end to end, via CDF, but it could offer advantages to frequencies elsewhere.
So your roughly 1 hour 5 minute direct commute now changes so you spend roughly the same amount of time on a train, but you have to change at Queen Street and fight to get on another overcrowded tram and so you have to add on say ten minutes aswell as the extra inconvenience? Not really going to go down well is it! Again, not convinced by comparisons to London because, again, it is something that currently is possible and so losing that would be a downgrade, not an improvement. If LU changed say the Bakerloo Line services so you had to change at Oxford Circus for services to anywhere north of that, I can imagine many people being annoyed.
On structural challenges: Sure. But any expansion of the network will involve structural challenges.
True, but at least with what the WG seem to want to do, the challenges are much much greater with light rail. Heavy rail electrification is a fairly known bit of work, and so the electrification of the valleys should not be too difficult once the funding problems are sorted. Light rail on the other hand, especially the ideas of street running and joining up here there and everywhere requires a lot of thought, a lot of heavy engineering and in many places the complete redesign and rebuilding of road layout and junctions, of residential areas and of commercial areas.
On through ticketing: I agree with you. Through tickets to the rest of the National Rail network must be maintained. Though if it's only a few quid extra for your journey, extending from Cardiff Central to Treherbert (return), then that suggests the fares are too cheap.
But who is going to ensure it is maintained?
And it really doesn't - it is commonplace that a through ticket is cheaper than buying separate tickets for the journey (of course, there are also many cases where because of badly priced flows, split ticketing is cheaper, but those are specific cases rather than how the system usually works).
With light rail: you'll be able to run more trains in shorter signaling blocks, the opportunity for expansions beyond the current network via on-street running where necessary, in particular supporting extension of Cardiff North East/Cardiff North West development areas. You won't get that with heavy rail, even after the CASR upgrade which delivered what, four additional paths per hour between CDF and CQS?
The question is - what do you guys who favour heavy rail think can be achieved over the next 10-20 years via electrification and cascaded EMUs, even in the unlikely scenario of VoG line and Maesteg / Ebbw Valey etc. all getting wired? I think you'd get a few extra stations between Cardiff and Newport on the relief lines, maybe one extra train to the fringes of the Core Valley lines, a Caerphilly terminator, maybe a Pontypridd terminator, a better Sunday service (could be delivered now), perhaps an extra train via the VoG line to Rhoose/Llantwit Major, and nothing more.
If you want street running and trams to areas currently not served by rail, why can't there be a seperate tram system that has a stop as part of Central station? Why does that idea (which I agree is a good one) have to inconvenience the entire upper valleys population who rely on a heavy rail connection to Cardiff Central and connections from there to the rest of the UK?
In terms of HR electrification with cascaded EMU's and a bit more investment, you could have 3 trains and hour for each valley (so 9 an hour from Pontypridd to Cardiff Central), each of them at least 3 carriages long.
Again I am not against light rail for the immediate areas around Cardiff. What I am saying is an issue is the expansion of that to the wider valleys lines, areas that are not part of Cardiff and are actually quite a distance away, is not the correct solution. By all means look at a tram-train solution if that helps save money in terms of combining the schemes, but at the very very least you need to maintain the existing journey times, the existing journey comfort (aka outside of peak hours the ability for most passengers to have a seat), the through ticketing (without increasing prices more so than what tickets are already increasing in cost by) and the existing journey opportunities. Basically, you cannot downgrade any parts of the existing service - to do so would be insane and a massive mistake when we should be improving the service!
