Ahh, that's a shame, thanks for the info though! So I guess we're back to Crewe to Holyhead taking 1hr 30m at best?! So we're looking at something close to 6hrs at best (and then you're only at Dublin Port, so another half an hour into the centre).
I'd suggest that the demand for this route will grow over the coming years as people try to reduce their carbon footprint, plus flying being such a horrible experience these days.
A flight from London to Dublin takes about 1hr 20m, assuming you check in 2 hours early and it takes half an hour from the plane landing to getting out of the airport, plus an hour getting to and from the airports to the city centres at each end that's also around 6 hours. So if the train and ferry companies made the route as good as it could be (ignoring upgrades), then it would be pretty comparable on time. And I'm sure the people of Rhyl wouldn't mind maybe one train from Euston 44,777,000 flying past a day.
I think that you’re being wildly optimistic about people reducing flights out of Ireland. Dublin Airport, which has recently opened a new runway to cope with the demand, is now reporting record numbers of people flying each month, exceeding pre-pandemic numbers.
As I’ve posted before, Aer Lingus alone have 88 flights a week between Dublin and Heathrow in each direction, and BA a further 36.
This summer there are 817 flights a week in each direction between Dublin airport and GB airports across all airlines, 320 of which are to London airports.
The notion that these people are going to switch back to train and ferry in large numbers is just fantasy.
The ferry companies aren’t interested in foot passengers, as evidenced by the ferry timetable change on Rosslare-Fishguard in July which breaks all the rail connections in Rosslare and the evening one in Fishguard coming from Rosslare.
Travelling on Wednesday 18th October I can get from my home in south Dublin, which is the far side of the city from Dublin airport, to Tottenham Court Road as follows:
Home depart 05:55
Airport arrive 07:13
DUB 08:45
LHR 10:15
Heathrow T123 dep 10:50
TCR arr 11:24
That’s 5 hours 30 mins.
Taking the normal ferry it is:
Home depart 05:55
City centre arrive 06:34
(Ferrylink bus)
City centre depart 06:50
Dublin port arrive 07:20
Dublin Port depart 08:05
Holyhead arrive 11:30
Holyhead depart 12:49
Euston arrive 16:35
Euston dep 16:46
TCR arrive 16:52
Total time taken: 11 hours
Taking the 08:00 SWIFT sailing arriving Holyhead at 10:15, the arrival time at TCR is 16:25 and that has two changes of train en route at Chester and Crewe using the 11:33 departure from Holyhead - total time taken would be 10 hours 30 mins.
You *might* make the 10:40 train from Holyhead if you were lucky, which would get you to TCR for 14:55 but that is still 9 hours.
(The connections from ferry to train are not quick in Holyhead as it is a bus transfer off the ferry - so you have to allow 30 mins to get to the station. Check-in time for ferry is 30 mins minimum).
To be quite honest, it is just not an attractive proposition unless you want to enjoy the delights of the countryside en route.
The notion that Irish people are going to revert to that kind of travel in any great numbers is bonkers.