A version of this content was originally posted on the #Railnatter Discord in January 2025

A while back, there was a discussion on the #Railnatter Discord about things that could be enabled by an Irish Sea fixed link, in particular in conjunction with High Speed 2. Somehow, the idea of a “high-speed sleeper” from Dublin to Berlin got thrown out.

And being the fool that I am, I had to put together a possible timetable for it.

Assumptions

  • The tunnel will go from Dublin Connolly, for better connections to Belfast (making it more palatable to the UK Government).
  • The tunnel will be 1435mm gauge, to allow through trains to Britain and Europe (at the expense of trains further west in Ireland).
  • The tunnel will make landfall at Holyhead station, parallel to the current railway.
  • The tunnel will have a maximum speed of 160km/h, similar to the Channel Tunnel. (Allowing speeds of 260km/h similarly to the Seikan Tunnel would be nicer, of course.)
  • The North Wales Mainline will be upgraded to or paralleled with a 250+km/h railway, meeting HS2 phase 1 just north of Crewe
  • Speaking of which: HS2 phase 1 is built
  • The HS1–HS2 link is built
  • Sleeper stock can be sourced that can run at 250km/h, and that is compatible with British, French, Belgian, and German railways
  • The passport control issue can be solved
  • Five-minute dwell times at each station call
  • Estimated times based on line speed and distance from Dublin–London
  • OpenRailRouting times on routes from London onwards, scaled by the difference between line speed and 220km/h speed where the latter is lower

(These last two are somewhat flawed assumptions, but picking 220km/h when we plan to run at 250km/h hopefully makes up for some of them.)

The timetable

Station Distance total /km Arrive Depart
Dublin Connolly 0   19:00
Holyhead 110 19:41 19:41
Bangor 150 19:52 19:57
Crewe 281 20:32 20:37
Birmingham Interchange 376 21:03 21:08
Old Oak Common 524 21:49 21:54
Stratford International 543 22:01 22:06
Ashford International 593 22:19 22:24
Calais Frethun 668 23:55 00:00
Lille Europe 769 00:54 00:59
Bruxelles-Midi 875 01:56 02:01
Aachen Hbf 1028 03:34 03:39
Köln Hbf 1098 04:15 04:20
Bielefeld Hbf 1285 06:01 06:06
Hannover Hbf 1394 06:59 07:04
Wolfsburg Hbf 1468 07:34 07:39
Berlin Hbf 1651 09:07  

A 13-hour trip to go a thousand miles, and an average speed of 125 km/h. This is a little more than the average speed of current European sleeper trains, but this is supposed to be a high-speed sleeper so that doesn’t seem unreasonable.

Even not going at full speed all the way, three hours Dublin–London isn’t bad, and would be competitive with air. I’m doing a trip to Odense soon, and it’s just the wrong distance away: too far to do in one day, but too close to have a useful sleeper service by the time you get to the continent. (You end up going too far, then getting off in the middle of the night in Copenhagen and having to double back.) So I’m ending up needing to stay a night en-route in each direction, which really pushes the cost up (which otherwise would be pretty competitive with flying, once you include the train connections to and from the airport). So this route could be useful to me: take GWR to Old Oak Common sleep from there to Hannover, then in the morning double back slightly to Hamburg, and then onward to Odense, getting there in well under 24 hours.