Only semi-speculative this one...
(The short version, to save you reading this long post if you don't want the detail, is that the fixed TfW paths to Manchester and Birmingham don't seem to permit what TfW seem to have proposed).
We know that TfW proposed introducing a service every two hours between Liverpool and Cardiff from December 2022 and hourly Liverpool-Shrewsbury services. Meanwhile, there is no indication that the current Holyhead to Cardiff service (also every two hours) would be reduced. Although the Liverpool trains don't seem to have been written into the Train Service Requirements (TSR) as a through service, the December 2022 TSR suggests 2tph between Shrewsbury and Chester and 2tph between Cardiff and Shrewsbury.
Where the speculation comes in is when I try to construct a possible timetable for the route with these additions. I am making the following assumptions:
As you can see, with these times Hereford would have a perfect half-hourly service (as do Ludlow, Leominster and Abergavenny although not all of these are shown).
Now, in order to take up its path into Birmingham, the service from Holyhead/Chester/Wrexham needs to arrive in Shrewsbury at about xx:30. That means a clockface half-hourly service north of Shrewsbury would look something like this:
This looks good until I try and combine it with the service south of Shrewsbury. The services departing Chester at six minutes past the hour do of course map nicely onto the xx:03 departures from Shrewsbury. Since they are the only hourly path available I have assumed these would be from Liverpool while the 36-mins-past the odd hours departure from Chester, running in the opposite hour from the Holyhead-Birmingham, would be the Holyhead-Cardiff. However, arriving at Shrewsbury at half past the hour, the service from Holyhead cannot easily continue to Cardiff since the Manchester to Cardiff service would only be about 12-13 minutes behind it from Shrewsbury. You could of course just use the xx:06 slot off Chester for services to Cardiff, with the train starting back from Holyhead in some hours and Liverpool in the others, but then you would not get hourly Liverpool to Shrewsbury services.
Northbound is even more problematic. The Manchester arrives at Shrewsbury from Cardif at xx:56, if I gave Hereford the same half-hourly perfection I managed southbound the marches stopper would arrive at xx:33, meaning it cannot depart towards Chester until xx:35 and would therefore miss its slot on the single line north of Wrexham. Even if you doubled the remaining single line section, the Birmingham to Holyhead/Chester arrives in Shrewsbury at xx:24 (odd hours), meaning it would have to wait over 10 minutes to run exactly an hour ahead/behind the Cardiff to Chester service. Even worse, it is closer to being exactly an hour ahead/behind the Cardiff to Chester service than it is to being exactly half an hour ahead/behind. As a result, while you can run an hourly Chester to Cardiff service southbound you cannot run hourly northbound as you have the fixed path to Manchester blocking one half hour and the Birmingham to Chester/Holyhead blocking the other. The best I have been able to come up with northbound is therefore Cardiff to Chester every two hours with a short working to Shrewsbury in the other hours (at 24/36 minute intervals at Hereford when combined with the Manchester rather than pure half-hourly).
Am I missing something?
(The short version, to save you reading this long post if you don't want the detail, is that the fixed TfW paths to Manchester and Birmingham don't seem to permit what TfW seem to have proposed).
We know that TfW proposed introducing a service every two hours between Liverpool and Cardiff from December 2022 and hourly Liverpool-Shrewsbury services. Meanwhile, there is no indication that the current Holyhead to Cardiff service (also every two hours) would be reduced. Although the Liverpool trains don't seem to have been written into the Train Service Requirements (TSR) as a through service, the December 2022 TSR suggests 2tph between Shrewsbury and Chester and 2tph between Cardiff and Shrewsbury.
Where the speculation comes in is when I try to construct a possible timetable for the route with these additions. I am making the following assumptions:
- Birmingham to Wrexham/Chester/Holyhead services must depart Birmingham International at xx:11
- Holyhead/Chester/Wrexham to Birmingham services must arrive Birmingham International at xx:50
- Manchester to Cardiff/Swansea services must depart Manchester Piccadilly at xx:31
- Cardiff/Swansea to Manchester services must arrive Manchester Piccadilly at xx:13
- 2tph services should be scheduled at, as close as possible, half-hour intervals
Manchester | 07:31 | - | 08:31 | - |
Shrewsbury (dep) | 08:40 | 09:03 | 09:40 | 10:03 |
Church Stretton | - | 09:18 | - | 10:18 |
Craven Arms | - | 09:28 | - | 10:28 |
Ludlow | 09:06 | 09:36 | 10:06 | 10:36 |
Hereford (arr) | 09:30 | 10:00 | 10:30 | 11:00 |
Pontypool & New Inn | - | 10:34 | - | 11:34 |
Cardiff Central | 10:31 | 11:03 | 11:31 | 12:03 |
As you can see, with these times Hereford would have a perfect half-hourly service (as do Ludlow, Leominster and Abergavenny although not all of these are shown).
Now, in order to take up its path into Birmingham, the service from Holyhead/Chester/Wrexham needs to arrive in Shrewsbury at about xx:30. That means a clockface half-hourly service north of Shrewsbury would look something like this:
Arrives at CTR from | HHD | LIV | HHD | LIV |
Chester (dep) | 08:36 | 09:06 | 09:36 | 10:06 |
Wrexham General | 08:51 | 09:21 | 09:51 | 10:21 |
Shrewsbury (arr) | 09:30 | 10:00 | 10:30 | 11:00 |
Shrewsbury (dep) | 09:33 | - | - | - |
Birmingham International | 10:50 | - | - | - |
This looks good until I try and combine it with the service south of Shrewsbury. The services departing Chester at six minutes past the hour do of course map nicely onto the xx:03 departures from Shrewsbury. Since they are the only hourly path available I have assumed these would be from Liverpool while the 36-mins-past the odd hours departure from Chester, running in the opposite hour from the Holyhead-Birmingham, would be the Holyhead-Cardiff. However, arriving at Shrewsbury at half past the hour, the service from Holyhead cannot easily continue to Cardiff since the Manchester to Cardiff service would only be about 12-13 minutes behind it from Shrewsbury. You could of course just use the xx:06 slot off Chester for services to Cardiff, with the train starting back from Holyhead in some hours and Liverpool in the others, but then you would not get hourly Liverpool to Shrewsbury services.
Northbound is even more problematic. The Manchester arrives at Shrewsbury from Cardif at xx:56, if I gave Hereford the same half-hourly perfection I managed southbound the marches stopper would arrive at xx:33, meaning it cannot depart towards Chester until xx:35 and would therefore miss its slot on the single line north of Wrexham. Even if you doubled the remaining single line section, the Birmingham to Holyhead/Chester arrives in Shrewsbury at xx:24 (odd hours), meaning it would have to wait over 10 minutes to run exactly an hour ahead/behind the Cardiff to Chester service. Even worse, it is closer to being exactly an hour ahead/behind the Cardiff to Chester service than it is to being exactly half an hour ahead/behind. As a result, while you can run an hourly Chester to Cardiff service southbound you cannot run hourly northbound as you have the fixed path to Manchester blocking one half hour and the Birmingham to Chester/Holyhead blocking the other. The best I have been able to come up with northbound is therefore Cardiff to Chester every two hours with a short working to Shrewsbury in the other hours (at 24/36 minute intervals at Hereford when combined with the Manchester rather than pure half-hourly).
Am I missing something?