Quote:
Originally Posted by James Howard
The 10 minutes extra running time on Sligo is nothing to with waiting for crossing. They generally make the up train wait at Edgeworthstown anyway, but even if down train was waiting at Edgeworthstown it wouldn't affect people going there. You're right, a lot of the drop in reliability for Sligo is due to the fact that every train now has to cross with at least 2 others - if not more. Until a couple of years ago, there was one train that had to cross with 5 others and things have got a bit better since they got rid of that.
What amazes me is that stuff like this can go into timetables and remain there for years - another example is the 1905 to Sligo which is 10 minutes late at Mullingar every single time I take it and has been for the last 7 years or however long it's been running. The proposed timetable has a proposed 1700 departure from Docklands which any idiot can see will hold up the 1705 Connolly express departure. How can a supposed planning expert come up with this kind of stuff?
The sad thing about all of this is that a supposed service improvement which will cost more money to operate has ended up pissing everyone off, makes nothing significantly better for anyone that couldn't be sorted another way and makes things significantly worse for the vast majority of railway users.
Anyway, I can't see this timetable change happening given that it will only run for about 6 months before the PPT is done. There should also be further modifications when BXD opens to take advantage of improved connectivity at Broombridge, but I wouldn't be surprised if that didn't happen.
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Within the existing timetable, most trains cross with three trains en route:
the first at Maynooth, the second at Edgeworthstown and the third at Boyle.
That imposes restrictions in terms of how the railway can operate and on overall journey times. The timetable has some resilience built into it - trains in the "down" direction (i.e. towards Sligo) have extra dwell time built into the schedule at Edgeworthstown and trains in the "up" direction (i.e. towards Dublin) have extra dwell time built into the schedule at Boyle.
You have to have that on single track routes in order to have some resilience in the event of a train being delayed somewhere, otherwise everything would collapse. This is standard practice in scheduling. It's not there for a whim - it's there to try and keep the service running as reliably as possible. It's certainly not a ridiculous idea by any means. One look at similar single track lines anywhere will show you that the same principle is applied.
The number of trains was reduced by one in either direction simply as a cost cutting measure - nothing more than that, but it has the effect of reducing the possibility of delays to the 18:00 from Sligo and the trains that it crosses.
I can't comment on why the 19:05 is delayed, but something is obviously delaying the 18:00 further along the line and causing the 19:05 to wait longer at Killucan than it is supposed to.
I don't think that the 17:00 ex-Docklands would impact on the 17:05 that much to be honest - it's a shorter route to Glasnevin Junction from Docklands than from Connolly, so it should be about 10 minutes ahead of it by there, which allowing for 30 second station stops, should still have it 5 minutes ahead of the 17:05 at Clonsilla. The 17:05 also has to cross the 15:00 at Maynooth, so accelerating the 17:05 any more isn't going to solve anything.
With infrastructure limitations such as mixing Intercity and Commuter services with no passing facilities, and running a reasonably frequent service on a single track, scheduling can be a bloody difficult job to do - far more difficult than most people even remotely consider.
And to clarify, the comment that I made about the Sligo line changes was in relation to the slightly longer journey times for most trains - and that it is, from what I can glean, looking in detail at the proposed timetables, in all likelihood down to changes in the permanent speed restrictions for whatever reason, which has meant that maintaining the clock face timetable becomes impossible.
Now the question I would have is what's causing the changes in the PSRs? Is it to do with changes in sighting for signals or what?
Also, if you then sit down and try to path in the extra Friday train around 16:00 it's nigh on impossible to do it any faster with the new running times - having examined it I don't see how it can be accelerated.
The lunchtime "down" service in the proposed timetable could however be accelerated somewhat by leaving 40 minutes earlier - why it's scheduled as it is, is beyond me.