[article] Proposal to bring train journey times between cities below two hours

[Inniskeen]

Originally Posted by Mark Gleeson

There is a series of restrictions approaching Cork which brings things to 60mph 4 miles out when in fact it should be 60 at the tunnel mouth, that makes a big difference. Dublin bound the limits are actually more generous and are in most cases rise faster than the trains ability to accelerate due the stiff hill

Combined with the excessive padding minimum 5 minutes to be saved inbound.

Curragh curves were 80 mph in the past so no gain there. 80 through Portarlington appeared in late 2007 and is key to the 2:30 timings. The Hazelhatch Cherry Orchard section offsets the go slow in the Hazelhatch Kildare section which is dug up in places currently.

There is more work to be done that when an increase in speed appears it is killed by temporary restrictions elsewhere. Lisduff will be dug up shortly so any gain elsewhere will be wiped out. Limerick Junction is great on paper but since most trains stop there the time saved is minimal. In some places the track is capable of more but the signaling restricts the top speed, so Ballybrophy is still 70mph, the signal spacing looks a little tight to me for faster.

There is a need for much greater coordination of the works to ensure minimum delay and maximum benefit

The 2011 timetable did shave several minutes off many times, not enough but it does deliver punctuality, in 2009 10-15 minute delays were the norm which led to regular problems. Punctuality comes first

The 2:30 time currently offered is a much greater achievement than the once off 2:20 timing of the past, particularly as the 2:30 timing is achieved with absolute adherence to the speed limits on a much busier railway. Quickest way to see savings is to bring the train every two hours to Limerick back and to run non stop to Thurles from Dublin on all Cork trains, and also fewer calls at Limerick Junction then you could bring most Dublin Cork trains to 2:35-2:45. The average time to Cork has fallen significantly (and thats what really actually matters to passengers) in recent times as the 75 mph stock has gone to the scrapyard. There is progress but the pace of progress is not sufficient

Sorry Mark - I misinterpreted what you meant by the throat of the Cork station, I assumed you were taking about the track immediately south of the tunnel.

While the final few miles of the southbound line into Cork are indeed subject to a gradually reducing speed limit this is most unlikely to be significantly altered as it ensures that trains approach Cork station in a safe manner consistent with a severe downgrade leading to the sharply curved track through the station.

The restrictions at the Curragh were initially eased in 2005, subsequently re-imposed and then eased again.

Will the work at Lisduff you mention really result in an improvement in line speed given that the small fortune spent at Ballybrophy in last few years has yielded a speed limit of 70mph - less than that which applied at the same place in the 1990s. The signalling at Ballybrophy imposes absolutely no restriction on line speed - signal spacing and controls are designed for at least 90mph.

Limerick Junction is another example of a shedload of money spent on track and signalling without any improvement in line speed (apart from through Grange and Emly). The speed limit on the main running lines remains at 25mph compared to 60mph in the 1990s.

The previously achieved Dublin/Cork and Cork/Dublin 2hr-20 minute non-stop timing I mentioned was not a one-off and was routinely achieved or bettered. It lasted for up to 10 years and the sectional timings formed the basis for scheduling the principal services on the line with end to end journey times depending on the stopping pattern.

Given the record of under-performance in recent years I am really unconvinced that yet another tranche of investment will lead to worthwhile improvements.