A puzzle - designing a new clockface timetable

[Rhydgaled]

This is somthing I've been coming back to on and off for over a year and not figured out. The South West Wales Intergrated Transport Consortium (SWWITCH) have a long-ish term asperation for 2.5 trains per hour from Carmarthen, with 1 per hour to Milford Haven (one fast (presumablly the current one from Manchester) and one stopper to Swansea), and 1 every 2-hours to Pembroke Dock (the current stopping service to Swansea) and new services to Fishguard.

I personally think there should be faster services between Cardiff and Carmarthen, using the Swansea District Line and I would say it would be nice to have the following 6 services per two-hours (3 per hour):

Milford Haven - Swansea (stopper)
Fishguard & Goodwick / Fishguard Harbour - Portsmouth Harbour (via Swansea District Line)
Carmarthen - Manchester (via Swansea District Line)
Pembroke Dock - Swansea (stopper)
Milford Haven - Manchester (fast via Swansea High Street)
Carmarthen - Portsmouth Harbour (fast via Swansea High Street)

The problem is I can't figure out a decent clockface timetable that keeps the services nicely spaced out (eg. keeping Milford Haven services exactly an hour apart and the two services that go no further west than Carmarthen and the two that use the district line also an hour apart). Is there even a solution to this puzzle, and if not what's the best comprimise that can be made? All I know you can write the 6 services in 720 different orders, maybe one of those is the solution!

 

[truckman060473]

Aye, I know what you mean about the district line route getting to Cardiff quicker, the 14.20 ish from Carm. can get to Cardiff in approx 1.5hrs, same as the 20.00 from Cardiff gets to Carm. by 21.30 give or take a minute. Both of these are district line users (usually) and do not call at Swansea

 

[The Planner]

Clockface only means at the same times each hour, there isnt a rule that says they have to be the same amount of time apart.

 

[thelem]

No, but there's little point in having 3tph if they all leave within 5 minutes of each other.

 

[Greenback]

Why is there a Carmarthen to Portsmouth train? Will it be run by FGW?!

 

[anthony263]

Why is there a Carmarthen to Portsmouth train? Will it be run by FGW?!

It could be show as being operated by ATW between west wales & Cardiff/Bristol with FGW crews either taking over at Cardiff or Bristol TM

As for trains running via the swansea district line you have to be aware that the can get through to cardiff, ie especially if the Maesteg - Cardiff route is increased to every 30 minutes. I did come up with a timetable of routing services via the swansea district line through to Port Talbot then non stop to cardiff. Also maybe a stop at Morriston could be looked at as it should relieve some peak hour congestion on the M4

 

[Rhydgaled]

Why is there a Carmarthen to Portsmouth train? Will it be run by FGW?!

The Carmarthen - Portsmouth and Fishguard - Portsmouth are my suggestions, the SWWITCH proposals did not include services to Portsmouth, they were:

Manchester-Milford Haven, 0.5 tph;
Manchester-Carmarthen, 0.5 tph;
Swansea-Milford Haven (stopper), 0.5 tph;
Swansea-Carmarthen (either this or the Pembroke Dock service would be a stopper), 0.5 tph;
Swansea-Pembroke Dock, 0.5 tph;
Carmarthen-Fishguard, 5 trains per day.

The 5 trains per day point for Fishguard is a little unclear, WAG discussions about the 'Fishguard Trains Petition" talked about 5 additional trains, which would make 6 daytime trains in total. 6 trains each way (not counting the night train) would, if the unit from the last service spent the night in Fishguard, make a decent 2-hourly service although with a fairly early last train. (First train would leave Fishguard at 07:52, last at 17:56, first arrival would be at about 09:48 last at around 19:48 (would be 17:45ish from Cardiff)).

Anyway I think there should be district line services, because of the huge time savings between Carmarthen and Cardiff, and to minimise changes I think the Fishguard service should run at least to Cardiff. Portsmouth springs to mind because it would restore direct services from west Wales to Bristol and Portsmouth and reduce changes to get to other areas in southern England. I would envisage the Fishguard - Portsmouth service as a 2-car 158 calling at Whitland, Carmarthen, Llanelli, Bridgend and Cardiff Central were it would couple to another 2-car 158 for the trip to Portsmouth. Operators could be a problem (although I think the railways should be re-nationalised to save money) but until the franchises run out I'd have neutrally liveried units and put ATW staff on west of Cardiff and FGW staff elsewhere, having the train count for ORCATS purposes as being run by FGW east of Cardiff and ATW west thereof.

Back to the puzzle, obviously the 2 Milford trains would need to be an hour apart, and the Fishguard - district line service would need good connections with one of the two stoppers, which should also be as far apart as possible.

 

[tbtc]

I think there should be district line services, because of the huge time savings between Carmarthen and Cardiff, and to minimise changes

The trouble you have is that if you divert anything via the District Line then you lose both a service from West Wales into Swansea and a service from Swansea to Cardiff. Both are pretty decent flows.

To reintroduce those links you need a second DMU, so you end up needing extra units.

Best thing to do (IMHO) would be to concentrate on three trains an hour from Cardiff to Swansea (one "fast" from London, one "medium" from Manchester, one "slow" starting from Cardiff) well spaced out to give decent connections at Swansea.

The problem you'll have sending things via the District Line is that there's more demand from Milford/ Pembroke/ Carmarthen to Swansea than there is to Cardiff. Deprive them of their Swansea service and you'll lose trade.

Maybe if there is a half hourly service west of Swansea - hourly Manchester - Pembroke and hourly Cardiff - Milford Haven, with one additional unit running Fishguard - District Line - Cardiff? Stations like Llanelli/ Carmarthen get a solid half hourly service, plus there's a token service "direct" to Cardiff to test the water?

 

[Greenback]

I'm not sure about that!

There is a market for an hourly service to/from Swansea, plus the Pembroke stoppers as now, but it looks like that is what is being proposed here. At present, the times are really poor, with the Pembroke Dock train leaving only 5 minutes after the Carmarthen/Milford service (on the hour sit runs). If we have a better timetable, there is the prospect of a better spread of services as an improvement tot he W Wales and Swansea flows.

Quite a lot of people travel beyond Swansea, at least on the Carmarthen-Manchester trains. Over the past weeks I have talked to people going to Shrewsbury (Bishops Castle), Derby and Bristol plus loads on their way to Cardiff, Neath or Bridgend. Outside of peak commuting times the numbers who get on and off at Swansea are not as high as those who stay on, I'd say.

I think that the through services that now run have helped attract custom, as the change at Swansea is now avoided. A few years ago, going anywhere from West Wales usually meant a change at both Swansea and Cardiff (London excepted!). Now, Portsmouth, Southampton, Bristol TM, Bath, Saliisbury, Plymouth, Exeter, Birmingham, Cheltenham, Gloucester etc are all accessible with just one change at Cardiff Central. So, for me, and based on my daily observations, Cardiff is now a more improtant destination than Swansea, although it pains me to say it being a born and bred Jack!

 

[tbtc]

for me, and based on my daily observations, Cardiff is now a more important destination than Swansea, although it pains me to say it being a born and bred Jack!

Fair enough - things have changed since I was down there regularly

 

[Rhydgaled]

Also maybe a stop at Morriston could be looked at as it should relieve some peak hour congestion on the M4

The services I proposed above are intended to slash journey times between West Wales and Cardiff, so I wouldn't have them call at Morriston. I do think that Swansea's valley lines should be reopened also (starting with the 2 that are still existant as freight lines) with valley lines services from Llanelli to Swansea docks serving a station or two on the district line.

The trouble you have is that if you divert anything via the District Line then you lose both a service from West Wales into Swansea and a service from Swansea to Cardiff. Both are pretty decent flows.

I wasn't intending diverting any service that currently runs via Swansea High Street (except the Carmarthen - Manchester, but I'd replace it with the Carmarthen - Portsmouth that would go into Swansea). There would in fact be:
1tph West Wales - Swansea (stopper)
1tph Carmarthen - Cardiff via Swansea District Line (with 1 per 2-hours starting from Fishguard)
1tph Carmarthen - Cardiff fast via Swansea High Street (one per 2-hours from Milford)

So that's still 2tph to Swansea.


Anyway, any ideas on a suitable order for the services that would keep them nicely spaced out?

 

[Greenback]

The trouble with planning any timetable is that it must fit in with places all over the network. I believe the current Manchester to Cardiff times are constrained by capacity and pathing at Piccadilly, for example.

Mind you, I've always beena bit dubious about clockface timetables anyway. They rarely seem to be at exactly the same minutes poaste ach and every hour. From Llanelli going East, the departure times usually vary by a couple of minutes here and there, but it's not really a problem, most people just seem to think "well if I'm there at 25 past and 5 to, a train will turn up"!

Where have you started? I'd start from Carmarthen and Cardiff ine ach direction and work around the curent times as a starting point. Feel free to PM me if you like!

 

[anthony263]

I have come up with my own timetable which involvved having a Pembroke - Dock - Carmarthen - Cardiff - Cheltenham Spa service which operated via the swansea district line on a hourly basis with a stop at Morriston/Llandarcy (2 hourly between Carmarthen & Pembroke Dock) there would still be a train every 30 minutes to swansea as you would have a 2 hourly Shrewsbury - Llandrindon - Ammanford - Swansea service which would connect at Llanelli. The other option i looked at was to extend either the Nottingham - Cardiff services to west wales via the district line or the Portsmouth Hbr - Cardiff service.

 

[Rhydgaled]

Unfortunatly I think the Pembroke Dock train being only 5 mins away from the Milford - Manchester is unavoidable with the package of services I suggested above. This is because it has to be an hour away from the other stopper (from Milford), which needs to be an hour away from the fast Milford service.

On my test timetable I therefore have arrivals at Carmarthen from the west at 57 and 55 mins past one hour, and 43 and 57mins past in the other hour. (The services arriving at 57mins past are from Milford, the 55mins past is from Pembroke and the 43mins past from Fishguard. Dispite arriving at Carmarthen only 3mins apart, the 57 and 55 past are 5mins apart at Whitland, this is because I'm allowing the stoppers 2mins extra for a stop at St Clears to be added even further into the future).

I think sombody who can think 'outside the box' is needed here. Some ideas I've had in the past that may help include running certain services (mainly the Pembroke Branch) on an every 90mins basis and terminating Pembroke branch services at Tenby, with a 153 shuttling between Pembroke Dock and Tenby (to allow said 90min frequency).

 

[Greenback]

Sadly 'the box' is very limiting! As well as pathing and platforming issues, you have to think about staffing, stabling, stakeholders views, revenue and costs. Above all, you have to try and provide services that can attract custom, and I can;t see that forcing passnegers into a change at tenby is going to do much of that!

I'd still like to know which point you are starting from. Are you starting with a blank sheet of paper, and in effect making all other services fit around the West Wales plan? Or are you starting from the timings at Cardiff (or soemwhere else) as they are know, because we know it's wprkable, and then trying to fit extra services in? I'm interested because I have been pondering these types of improvements for a long time!

 

[Rhydgaled]

For the times above I started at Milford Haven with the train's current departure time of 11:08, but trying to allow for it to past the incoming train made it leave at 11:00 and hoped for the best. Then I just assumed the slot would be possible each and every hour, a bit dodgy but the time above help illustrate the problem I'm having spacing the services out.

Also, while requiring passengers to change at Tenby would hurt custom, an increased frequency would increase custom, but is requiring the change worth it to get the increased frequency?

 

[Tomnick]

I don't know what the headways are west of Carmarthen, but services running two minutes apart will definitely be a no-no - I wouldn't be surprised if it was approaching ten minutes.

 

[Rhydgaled]

I don't know what the headways are west of Carmarthen, but services running two minutes apart will definitely be a no-no - I wouldn't be surprised if it was approaching ten minutes.

Good point, I think the headway is 5 minutes actually (not sure my source is accurate, even though it was a Network Rail document), so you're right those times won't work. Why do I doubt the Network Rail document? because the linespeed maps in several of their documents conflict!

 

[The Planner]

Depends which way you are going. If you go via Swansea station and not the district, then the headways are 6 to Llanelli, AB between Llanelli, Pembury, Kidwelly, Ferryside and Camarthen Bridge Jn. After there it is 7 to Whitland and 8 from Whitland to Clarbeston Road. AB down to Milford Haven.

 

[Rhydgaled]

Depends which way you are going. If you go via Swansea station and not the district, then the headways are 6 to Llanelli, AB between Llanelli, Pembury, Kidwelly, Ferryside and Camarthen Bridge Jn. After there it is 7 to Whitland and 8 from Whitland to Clarbeston Road. AB down to Milford Haven.

Does that mean a train cannot leave Llanelli until the proceding service has almost reached Carmarthen, or just when the proceding train has passed the next of the intermediate stations? Also, does this mean trains cannot pass at Haverfordwest?

I tried to find a slot to run the Fishguard - Portsmouth service, the current times put the train just behind a FGW PAD-SWA service, which will probablly slow the service down and means there's no point extending 2-cars to Swansea in the other hour (a problem, as the service in the other hour needs to loose 2 out of the 4 coaches otherwise it'll pick up another 2 from Fishguard (and the services that loose 2-coaches for Fishguard would only have 2 coaches on the way back to Portsmouth).

 

[Tomnick]

Does that mean a train cannot leave Llanelli until the proceding service has almost reached Carmarthen, or just when the proceding train has passed the next of the intermediate stations? Also, does this mean trains cannot pass at Haverfordwest?

Headway through AB sections, if I'm not mistaken, is equal to the section time between each pair of signalboxes (or IB signals, as provided between Whitland and Clarbeston Road) plus two minutes. No reason why two couldn't pass at Haverfordwest, or why a following one couldn't leave Clarbeston Road once the first has arrived at (not sure what the overlap conditions are) Haverfordwest.

 

[Greenback]

Does that mean a train cannot leave Llanelli until the proceding service has almost reached Carmarthen

No, the current timetable where a Carmerthen train leaves Swanse at 1600, and a Pembroke Dock train at 1605 would not be possible if that was the case!

 

[The Planner]

Maybe I should have explained it better, basically, you cant pass Llanelli until 2 minutes after you have passed Pembury, and so on and so forth.

 

[Rhydgaled]

Headway through AB sections, if I'm not mistaken, is equal to the section time between each pair of signalboxes (or IB signals, as provided between Whitland and Clarbeston Road) plus two minutes. No reason why two couldn't pass at Haverfordwest, or why a following one couldn't leave Clarbeston Road once the first has arrived at (not sure what the overlap conditions are) Haverfordwest.

Does that mean a train cannot leave Llanelli until the proceding service has almost reached Carmarthen

No, the current timetable where a Carmerthen train leaves Swanse at 1600, and a Pembroke Dock train at 1605 would not be possible if that was the case!

Maybe I should have explained it better, basically, you cant pass Llanelli until 2 minutes after you have passed Pembury, and so on and so forth.

Thanks for clearing that up, now back to the puzzle. As I said above there may be a problem with the Portsmouth service. Anyone have ideas on that, or another asspect of my plan in the making?