Theirs some speculation that through workings from the coast may have to be suspended when/if an hourly service to Aberystwyth in instigated due to the single track section between Dovey Jnc and Machynlleth being occupied by additional Aberystwyth workings.
It will be very tight in that single line section (ideally it would be double track but it will never happen). In fact the hourly service will be even more susceptible to delays than the current 2 hourly service. Due to the need to pass at loops and only approx 10 min turn around time at Aberyswyth it is difficult to make up time once any train is late (trains end up being late the whole day). The coast is not so bad as there is standing time at Machynlleth, Barmouth and quite a long turn at Pwllheli. From a train running point of view it would be much easier to only run the coast service to and from Dovey Junction, however, the number of passengers and amount of luggage would cause an big inconvenience to passengers. There is also the crew change issue (depot is at Machynlleth) but this isn't really a problem as the train could run ECS to Machynlleth in the gaps between service.
I can see a number of options for hourly service to Aberystwyth and 2 hourly to Pwllheli (please bear in mind I have not calculated exact timings):
When there is a Down Pwllheli Train:
Option 1a) If trains run similar to current time table then you would run the DOWN Aberystwyth first to Dovey Junction, where it would pass the UP train coming from Aberystwyth using hte new loop. The UP train would then travel to Machynlleth where the 2 cars for Pwllheli are still waiting. Not sure what the exact timings would be but I'd say it would be at least 14-17 mins from the time the Aberystwyth train leaving Machynlleth to the UP train getting back in again.
Option 1b) Pwllheli Train could depart immediately behind Aberystwyth train.
The Down Aberystwyth train leaving Machynlleth currently takes about 2:30 to clear the first half of the single line sections. So Pwllheli train could run behind it 3 minutes later. It would then run into the Coast line platform and Dovey Junction before the UP train from Aberystwyth passes.
Pwllheli Train in UP direction
Option 2a) At the moment the UP from Pwllheli arrives into Machynlleth about 6-10 mins advance of the UP from Aberyswyth. It would need to be re-timed to get in 15 mins earlier to pass the Down Aberystwyth at Machynlleth.
Option 2b) Trian in Up direction leaving Dovey Junction station takes approx 3:45 mins to clear the first half of the single line section. So in theory you could run a 4 min headway and have the Down Aberystwyth train running into Dovery Junction first, then the UP from Pwllheli, then the UP from Aberystwyth.
So the ideal solutions would be Options 1a and 2a, but it removes the slack that they currently have in the timetable. I would imagine they would go for the b options and the signallers would use the a option when trains are running late.
Anyway, it would be nice to see the hourly service come in... perhaps initially just in the peak direction to let it bed in. Another idea someone has already suggested on this forum previously would to have off-peak services running only hourly to Newtown (this would allow for some ecovery time).
