29K still on Rosslare and Sligo lines

[Kilocharlie]

Originally Posted by Inniskeen

Why does the DART take between 16% and 25% longer to travel from Bray to Connolly than in 1984 ?

DART opened in 1984 from Bray to Howth, hence 1984. Could have used 1985, 1986, 1987, perhaps even 1995 (need to check 1995 TT to confirm). Point is that the journey times have gotten significantly slower adding to congestion and track occupancy, reducing crew and equipment productivity and making the service less attractive than it needs to be.

Greystones is a comparison between current DART and diesel running times !

Where do you get the 25% to 40% faster times?
Most DARTs take 9 mins, one or two take 10. Most Intercitys take 9 mins with one at 8 mins. Take the slowest DART and fastest Intercity you get a ratio of 10:8 which could be argued that the DART is 25% slower or the Intercity 20% faster. Where is the 40%?

For the vast majority both DART and Intecity take the same 9 mins.

[Inniskeen]

Originally Posted by Kilocharlie

Where do you get the 25% to 40% faster times?
Most DARTs take 9 mins, one or two take 10. Most Intercitys take 9 mins with one at 8 mins. Take the slowest DART and fastest Intercity you get a ratio of 10:8 which could be argued that the DART is 25% slower or the Intercity 20% faster. Where is the 40%?

For the vast majority both DART and Intecity take the same 9 mins.

In my experience DART never takes less than 9 minutes and not infrequently takes 9'-30" or more while a diesel railcar running on clear signals typically takes about 7½ minutes and sometimes as little as 6'-45" without exceeding any posted speed limits.

DART running time 9'-00", Diesel running time 7'-30", Diff 1'-30"/7'-30" represents a 20% premium.

DART running time 9'-30", Diesel running time 7'-30", Diff 2'-00"/7'-30" represents a 27% premium.

DART running time 9'-30", Diesel running time 6'-45", Diff 2'-45"/7'-30" represents a 41% premium.

I think 25% to 40% is a good approximation of relative performance. The bottom line is that DART is significantly slower than a diesel in this section and consequently reduces line capacity.

DART underperforms diesels elsewhere, another example being Portmarnock to Malahide where DART typically takes 50" to 60" more than a diesel stopping at the same two stations.

[Kilocharlie]

Originally Posted by Inniskeen

In my experience DART never takes less than 9 minutes and not infrequently takes 9'-30" or more while a diesel railcar running on clear signals typically takes about 7½ minutes and sometimes as little as 6'-45" without exceeding any posted speed limits.

DART running time 9'-00", Diesel running time 7'-30", Diff 1'-30"/7'-30" represents a 20% premium.

DART running time 9'-30", Diesel running time 7'-30", Diff 2'-00"/7'-30" represents a 27% premium.

DART running time 9'-30", Diesel running time 6'-45", Diff 2'-45"/7'-30" represents a 41% premium.

I think 25% to 40% is a good approximation !

OK: reality vs timetable...

[Eddie]

Clearly the Dart can run reasonably fast as it does between Killiney and Bray.

In which case, why can it not go as fast as the diesels apparently can between other station through greater acceleration and deceleration?

Is there just not enough power in the overhead lines?

[Colm Moore]

Originally Posted by Inniskeen

DART underperforms diesels elsewhere, another example being Portmarnock to Malahide where DART typically takes 50" to 60" more than a diesel stopping at the same two stations.

DART top speed is about 62mph (diesel 70-100mph) and DART often operates via the crossover at Malahide to the southbound platform.

[shweeney]

Originally Posted by DangerM

The original post was asking about the Rosslare line specifically but the thread seems to have deviated, any idea when we will have a 22k train on the 16:37 and 17:36 routes?

those two services are primarily commuter runs, on the few occasions they've used 22Ks the train has been delayed at every station because it takes so long to get people on and off. Also the 22Ks may be more comfortable to sit on but they're substantially less comfortable than the commuter trains if you are standing.

[James Howard]

The original post was about both Rosslare and Sligo lines and both suffer from the same issue. The comfort and noise levels on 29ks is simple not suitable for a 3 hour run.

I would have to stop using the train at this point if I was to go back to spending 14 hours per week on 29Ks. On journeys any further out than Mullingar on the Sligo line, the 29K is simply unacceptable - they are nosier and less comfortable than the bus and the tables are too small to work on anyway which is my main reason for taking the train.

The problem on both the Sligo and Rosslare lines is that they have commuter services doing double-duty as intercity trains. On the Sligo line, they should work on separating the Longford services so that they only have limited stops beyond Maynooth - ideally Clonsilla and Drumcondra. This would knock about 15 minutes off the running time and allow them to run the services using shorter 22k trains.

I know - there is no money for this sort of thing but this is where a bit of innovative thinking needs to be applied. The inefficiency in the use of resources on the Longford line is terrible. A lot of trains are run at extremely low occupancy beyond Mullingar or even Maynooth in some cases.

[dowlingm]

The assertion in the OP is that IE have "plenty of 22Ks now". The reality is that most if not all of the 22s commissioned to date have simply replaced 28s and there is talk of Mark 4 sets being pulled out of the line for "deep cleaning" in the near future which will occupy 22s on replacement diagrams Heuston side.

[James Howard]

Well given that they can spare them for Dunboyne runs, they must have some to spare.

It is serious annoying to be on a packed 29K heading for Longford expecting to spend an hour and a half minimum on it and you see a 22k sailing into Docklands with a few dozen passengers. But I guess Irish Rail have their reasons - Irish transport organisations always seem to have a "better" way of doing things.

[dowlingm]

The Dunboyne runs fill in gaps in the diagrams where there isn't time to send the train further out. That issue has been addressed several times.

It would be nice if there was part of the Sligo line that could be cleared to 80mph+ to get real advantage out of the faster sets but I guess that's what you get when you build a line beside a canal?

[Kilocharlie]

Originally Posted by dowlingm

The Dunboyne runs fill in gaps in the diagrams where there isn't time to send the train further out. That issue has been addressed several times.

It would be nice if there was part of the Sligo line that could be cleared to 80mph+ to get real advantage out of the faster sets but I guess that's what you get when you build a line beside a canal?

On an historical note, the railway bought the Royal Canal and intended to fill it in for the railway. In the event they built it in parallel hence all the sharp curves. ( I know not really passenger related but it does explain the reason for the curves)

[James Howard]

One positive thing about the more widespread use of 22Ks on the Sligo line is that they really seem to have improved the punctuality statistics. This has been above 95% for the last few months.

There is definitely a pattern of the 18:05 down train being a few minutes early getting to Edgeworthstown when it is a 22K but the same service being a minute or two late when it a 29K.

Originally Posted by Inniskeen

As with so many aspects of railway operations, improvements do not necessarily require additional capital expenditures. Remember that huge sums have already been spent on rolling stock, track, signalling, bridges, level crossings and fencing. Is the investment that has taken place already being used to best effect ?

This is a very important point. Over the last decade the Sligo line has had extensive track renewal, new rolling stock (twice), new signalling, mostly new level crossings (and new mileposts ). There have been significant improvements in frequency and punctuality as a result of all of this but the running times have slightly dis-improved by a minute or two mainly due to extra stops.

I think that Irish Rail can do more with the resources they have on the Sligo line. For a start, they could re-allocate services that run mostly empty after Maynooth to provide a later service to Mullingar or Longford and they could also look at making the Longford commuter services skip some stops (maybe express between Clonsilla and Drumcondra). This would increase the productivity of the staff and equipment, save fuel and result in happier passengers but would obviously require a more precarious timetable. It might even allow them to get away with shorter trains on these runs and would allow them to use 22ks if available.

[Inniskeen]

Originally Posted by Colm Moore

DART top speed is about 62mph (diesel 70-100mph) and DART often operates via the crossover at Malahide to the southbound platform.

It is even slower again when it operates to the southbound platform !

As regards Sligo line services, James is very close to the mark - the current setup appears to be sub-optimal both in terms of resource utilisation and service provision.

As regards line speed on the Sligo line, much of the route is already cleared for 75mph. The Sligo line proper (beyond Mullingar) does'nt follow the canal and could easily sustain speeds of 80 mph or more. Many railway operators have differential speed limits for diesel locomotive hauled trains and railcars, as did CIE/UTA in the 1950s and 1960s. Given that 75mph running was already established for locomotive hauled trains, I would imagine that 80-85mph over worthwhile stretches of the Sligo line would only require the erection of appropriate boards !

[ACustomer]

Surely a major cause of DART underperformance on Bray-Greystones, or approaching Malahide, is that the ATP system imposes very slow (5 to 10 mph) approach speeds to a red light. Diesel units are not as restricted as they rely more on drivers' judgement of safe approach speeds.

[Inniskeen]

Originally Posted by ACustomer

Surely a major cause of DART underperformance on Bray-Greystones, or approaching Malahide, is that the ATP system imposes very slow (5 to 10 mph) approach speeds to a red light. Diesel units are not as restricted as they rely more on drivers' judgement of safe approach speeds.

Yes, the ATP is a factor. However in the case of Malahide why can't a DART enter the station on clear signals with full ATP clearance. Is there a fear that the driver will continue on in the absence of a red signal ? - would a board marking the limit of DART operations not make more sense ?

ATP adds about nine minutes to a Greystones/Bray to Malahide/Howth (e.g northbound approaching Booterstown). It is a fairly crude system- good in the 1980s perhaps, but perhaps could be replaced by a better design at this stage.

Other factors influencing DART performance are scheduling and door opening/closing times. ATP was there from the beginning of the DART service and is not responsible for the the significant extension of DART journey times over the years.

There is a clear need for a review of DART to ensure that operations are as efficient as possible so that DART causes the least practical disruption to other services sharing the same route. In particular, the recent huge expenditure and disruption in increasing the capacity of the DART system should be leveraged so that peak period DART demand is met by the least practical number of services (subject to a minimum 15 minute interval service between Howth Junction and Bray). Unnecessary DART frequency impedes other traffic and reduces the overall capacity and utility of the railway.

[Mark Gleeson]

At worst DART times are 10% more than before 60 vs 69 minutes, if you allow a total of 3 minutes for the two extra stops, the baseline is 60 vs 66. So this is no way as big an issue

Given its now a 6/8 coach operation vs the original 4 or even 2 coach (impacts on exiting speed restrictions) and the additional delay closing doors due the warning buzzer the extension in time is not excessive.

It is something we are discussing with IE management

First 6 coach train appeared in 1995 and from then onwards things got crazy busy

[Thomas Ralph]

But dwell time should be shorter the more coaches there are because you don't get people having to walk down the platform to the train.

(Doesn't arise here because the platform displays tell you how many coaches the train will have and there are nice boards showing you where a train of X coaches will stop, same as NIR.)