That, whilst I like service upgrades, just seems to not be needed. Why duplicate so much and take so many more paths when you can supply all the needs in one service?
It's only 1tph extra, how's that taking 'so many more paths'? One path, yes. The extra service would have fewer stops (should be Cardiff, Port Talbot, Morriston, Llanelli, Carmarthen in my view, possibly without the Morriston stop) which isn't really duplicating that much. To answer your question 'why', it takes less than 80 minutes to drive from Carmarthen to Cardiff, by train with a stop at Swansea is more like 100 minutes. I reckon bypassing Swansea would allow you to cut that to 85 minutes with the possibility of future enhancements (to deliver the Welsh Government's rail acceleration ambitions) cutting that further to something that is actually time competitive. You are never going to make a journey via Swansea time-competitive against the M4.
I’d even suggest, with a potential staycation boom lasting a couple of years, making Pembroke and, at least, Tenby hourly (I’m aware changes may need to be made).
So there’s 2 ways to do this west of Swansea:
1tp2h to each of Milford Haven and Pembroke
1tp2h GWR extension from Swansea to Tenby/Pembroke
OR
1tph to Pembroke
1tp2h to Milford Haven
1tp2h to Carmarthen slow
I believe the single line between Pembroke Dock and Tenby is occupied all day long Mon-Sat in the pre-COVID timetable. I'm not sure about Tenby-Whitland - that might be possible to do hourly with a unit that accelerates quickly but a half-hourly service between Whitland and Swansea (a combination of Milford and Pembroke Dock services) doesn't appear to be possible due to the round trip times between Whitland and Tenby/Milford being so radically different. It needs a loop at Templeton I think (which would limit the Pembroke & Tenby branch to a train every two hours unless you also put another new loop in west of Tenby).
Nor does Swansea need a Manchester service especially, or anywhere west of there. But I can understand why it exists.
I think Swansea should have a through fast service to somewhere well north of the M4 corridor - doesn't have to be Manchester but if you take the Manchester away you should do something like extend the Cardiff-Nottingham back to Swansea in its place.
If we make the (not necessarily correct) assumption that most people are travelling between Manchester and South Wales, wouldn't it be better to portion work a South Wales unit off of a Manchester-SW XC service, splitting in the vicinity of Worcester?
Doesn't have to use the welsh marches does it?
Interesting; I assumed using the Welsh marches route would be faster but is it? Forget portion working; if you gave XC a big shakeup and did the following would Swansea/Cardiff to Manchester be faster with XC than TfW?
- Swansea - Cardiff - Worcestershire Parkway - Birmingham - Manchester
- Penzance - Plymouth - Bristol - Birmingham - Leeds - Edinburgh - Aberdeen
- Paignton - Bristol - Worcestershire Parkway - Birmingham - Nottingham
- Manchester - Birmingham - Reading - Bournemouth
- Southampton - Reading - Birmingham - Doncaster - York - Scarborough