DART+ (DART Expansion)

MrAbyss

marno21 wrote: »

Imagine if the Bay Area was in Ireland how limited transport options would be.

Lots of time-lapse videos with repeating piano arpeggios and a patronizing voice overs.

LXFlyer

ncounties wrote: »

When will we actually see contractors onsite on the Kildare and Maynooth lines? Apologies if its already been stated, just a lot of activity on here in recent weeks.

Not even close to that point yet.

I wouldn’t be holding your breath.

DoctorPan

ncounties wrote: »

When will we actually see contractors onsite on the Kildare and Maynooth lines? Apologies if its already been stated, just a lot of activity on here in recent weeks.

Be a while yet, design tender for Maynooth only just closed on Monday last and Kildare line hasn't gone to full tender yet.

Rulmeq

CatInABox wrote: »

We've currently got nowhere to store any new carriages. The location for the new depot is out in Maynooth. No point electrifying the Kildare line if the trains can't get from Maynooth onto the Kildare line

Do you have any info on where this is going to be? I always assumed that the area just after Hazelhatch was going to be used as a depot/storage area because there's a lot of unused space and green fields there, but I guess Maynooth has something similar (although I would have thought more limited space due to the canal)

LXFlyer

Rulmeq wrote: »

Do you have any info on where this is going to be? I always assumed that the area just after Hazelhatch was going to be used as a depot/storage area because there's a lot of unused space and green fields there, but I guess Maynooth has something similar (although I would have thought more limited space due to the canal)

All of this has yet to be finalised.

People are jumping the gun here.

We haven’t even got to design stage for the DART expansion.

CatInABox

LXFlyer wrote: »

All of this has yet to be finalised.

People are jumping the gun here.

We haven’t even got to design stage for the DART expansion.

Yup, all I've got is what Irish Rail have said, i.e. Stabling/Maintenance depot on Maynooth line; Stabling Depot on Kildare line.

I'd assume that they have a general idea of where they should go, but it'll be the design doc before we see.

Pete_Cavan

With the stabling/maintenance depot on Maynooth, will Fairview still be used for stabling and driver change over? Would it be beneficial to the northern line to have a passing loop at Clontarf Road to allow commuters/Enterprises overtake DARTs stopped there, giving them a clear run north? It would be easy to turn the north bound platform into an island, perhaps put in arrangements to allow drivers change while the train is sitting in the station rather than 100m outside it.

loyatemu

Pete_Cavan wrote: »

perhaps put in arrangements to allow drivers change while the train is sitting in the station rather than 100m outside it.

that's crazy talk.

LXFlyer

Pete_Cavan wrote: »

With the stabling/maintenance depot on Maynooth, will Fairview still be used for stabling and driver change over? Would it be beneficial to the northern line to have a passing loop at Clontarf Road to allow commuters/Enterprises overtake DARTs stopped there, giving them a clear run north? It would be easy to turn the north bound platform into an island, perhaps put in arrangements to allow drivers change while the train is sitting in the station rather than 100m outside it.

In all likelihood there will still be, at a minimum, a stabling facility at Fairview - but again that hasn’t been spelt out in detail. Operationally, losing that would be insane.

Again, from an operational resilience perspective, a much longer overtaking facility located further north (ideally between Killester and Raheny) would be far more desirable. Being as close to Connolly as Clontarf Road is wouldn’t be that much use.

Pete_Cavan

LXFlyer wrote: »

Again, from an operational resilience perspective, a much longer overtaking facility located further north (ideally between Killester and Raheny) would be far more desirable. Being as close to Connolly as Clontarf Road is wouldn’t be that much use.

Could you explain that further for me please? I would have thought that having the overtaking section close to Connolly would be beneficial. It means, once it passes the DART, the commuter train can travel at speed up the line until it gets to it's next stop (HJ). The further north the overtake is, the more time the commuter train is constrained behind a stopping DART and less free run until it has to stop itself.

gooddarts10

LXFlyer wrote: »

In all likelihood there will still be, at a minimum, a stabling facility at Fairview - but again that hasn’t been spelt out in detail. Operationally, losing that would be insane.

Again, from an operational resilience perspective, a much longer overtaking facility located further north (ideally between Killester and Raheny) would be far more desirable. Being as close to Connolly as Clontarf Road is wouldn’t be that much use.

There are no plans to get rid of Fairview it’s to be upgraded along with the facility in Drogheda

LeinsterDub

Pete_Cavan wrote: »

With the stabling/maintenance depot on Maynooth, will Fairview still be used for stabling and driver change over? Would it be beneficial to the northern line to have a passing loop at Clontarf Road to allow commuters/Enterprises overtake DARTs stopped there, giving them a clear run north? It would be easy to turn the north bound platform into an island, perhaps put in arrangements to allow drivers change while the train is sitting in the station rather than 100m outside it.

It would only give them a clear run to the next DART ahead which would be a most 10 minutes down the line.

Pete_Cavan

LeinsterDub wrote: »

It would only give them a clear run to the next DART ahead which would be a most 10 minutes down the line.

10 minutes plus travelling time of the commuter train. As the commuter will still have to slow down and stop north of HJ anyway, I doubt the previous DART would be an issue and definitely wouldn't be if it is a Howth DART. Its still better than having the commuter trains sitting behind DARTs all the way up the line.

gjim

Pete_Cavan wrote: »

Could you explain that further for me please? I would have thought that having the overtaking section close to Connolly would be beneficial. It means, once it passes the DART, the commuter train can travel at speed up the line until it gets to it's next stop (HJ). The further north the overtake is, the more time the commuter train is constrained behind a stopping DART and less free run until it has to stop itself.

Surely you'd be aiming not to have a commuter leaving the station just after a DART in the first place? If commuters are scheduled to leave before DARTs, then a nearby passing loop will never be of benefit. While a more northerly passing loop could allow the commuter to pass a DART that had left 10 minutes before. Not sure I've explained that very well.

Or you can think of the whole of Connolly as a sort-of passing loop - there's limited additional utility to having another passing loop right next to it.

Pete_Cavan

gjim wrote: »

Surely you'd be aiming not to have a commuter leaving the station just after a DART in the first place? If commuters are scheduled to leave before DARTs, then a nearby passing loop will never be of benefit. While a more northerly passing loop could allow the commuter to pass a DART that had left 10 minutes before. Not sure I've explained that very well.

Or you can think of the whole of Connolly as a sort-of passing loop - there's limited additional utility to having another passing loop right next to it.

Well with DARTs every 10 minutes, even leaving before one DART, it is not long before the next one. I'm just thinking that if you can squeeze commuters closer to the DART ahead and overtake it, it should give a bit more flexibility and ease congestion.

Connolly can hardly be considered a passing loop, all the trains stop there anyway. The advantage of Clontarf Road is that the DART will be stopped there anyway, it might just have to sit for a bit until the commuter passes. If driver change happens there too, it makes things even more efficient. A few small time savings could be very useful on a busy line.

LXFlyer

Pete_Cavan wrote: »

Could you explain that further for me please? I would have thought that having the overtaking section close to Connolly would be beneficial. It means, once it passes the DART, the commuter train can travel at speed up the line until it gets to it's next stop (HJ). The further north the overtake is, the more time the commuter train is constrained behind a stopping DART and less free run until it has to stop itself.

There already is an overtaking facility directly north of Connolly with the separate running lines until North Stand Junction.

As I already mentioned, the ideal situation is an extended passing facility, in other words ideally four tracking (but a push three tracks) between Killester and Raheny, that allows for overtaking, and also allows for some timetable resilience built in, if services are running late for example.

Remember that the ability to pass is needed in both directions - putting it that close to Connolly would be a waste. It needs to be located roughly halfway between North Strand Junction and the next passing facilities which are at Howth Junction for Howth trains and Clongriffin for Northern Line trains.

FYI most commuter services run non-stop between Connolly and Malahide these days and don’t serve Howth Junction.

I do get what you’re saying, but scheduling trains is very intricate and to accurately understand this, you do have to sit down with a blank spreadsheet, sectional running times, and then path out all of the services. You also have to look at a train’s entire journey to see where the conflicts arise and what the potential knock-on effects of holding trains might me. It is a lot more complicated than most people appreciate.

Currently DART’s are only held for overtaking at Clongriffin - you don’t want to be holding them anywhere else, you want to be able to overtake them with little or no impact to their overall journey times, hence overtaking them on the move is preferable.

Pete_Cavan

LXFlyer wrote: »

I do get what you’re saying, but scheduling trains is very intricate and to accurately understand this, you do have to sit down with a blank spreadsheet, sectional running times, and then path out all of the services. You also have to look at a train’s entire journey to see where the conflicts arise and what the potential knock-on effects of holding trains might me. It is a lot more complicated than most people appreciate.

Fair enough but I think examining the benefits of it would be an exercise worth doing. The reality is that there won't be extra track between Killester and Raheny for a long time (if ever) and anything which might eek out a bit more flexibility on the line for little cost needs to be considered.

LXFlyer

Pete_Cavan wrote: »

Fair enough but I think examining the benefits of it would be an exercise worth doing. The reality is that there won't be extra track between Killester and Raheny for a long time (if ever) and anything which might eek out a bit more flexibility on the line for little cost needs to be considered.

If any form of competitive journey times for Dublin-Belfast and Northern Line services are going to be delivered there will have to be extra tracks laid down in that area.

CatInABox

Does anyone know which power supply the new Dart Expansion will use yet?

I saw that the tender for the new trains mentions a new system, but don't think anyone has heard anything else about it yet.

The trains will be compatible with the existing DART network overhead power supply of 1500v DC (i.e. current draw, traction profile under acceleration and re-generation) and also with the power supply for the proposed extension sections.

The tender is here.

Sam Russell

CatInABox wrote: »

Does anyone know which power supply the new Dart Expansion will use yet?

I think that the Metrolink will use 1500 V, rather than the 750 V used by Luas. It would be natural that the Dart expansion would be 100% Dart standard.

cgcsb

It'll be ac in order to be compatible with long distance services. There'll be some dual voltage trains and the current fleet will be limited to the current dart line for a time before being also replaced by dual voltage...eventually

CatInABox

Sam Russell wrote: »

I think that the Metrolink will use 1500 V, rather than the 750 V used by Luas. It would be natural that the Dart expansion would be 100% Dart standard.

I had thought that initially, but then why specifically mention a different standard in the tender for new trains?

I'd love if they actually had the forethought to plan for intercity electrification during this expansion as cgcsb says.

Last Stop

The tender doesn’t specifically mention a new system though?
It sounds like they haven’t decided.

I don’t think it has to be ac. Given the most likely line to be electrified is quad track they could have an up down up down configuration instead of the current up up down down.
From what I understand the main reason for not using dc on longer distance is the losses involved. Given that the longest distance that electrification would cover is 250km I don’t think the losses would be that significant.

cgcsb

The loses aren't the main reason. For dc the substations have to be closer together a long the route, every 2 or 3km. With ac the substations can easily be 25km apart

Last Stop

Fair enough. So that gives you 3 options:
1 Build all the dc substations
2 separate between ac and dc along the quad tracked Kildare line
3 have dual voltage intercity trains

I really don’t see why you would build a new system which would significantly impact the operations side of things for the sake of a project that may or may not go ahead. If you went with the new system, you’d have to upgrade the existing DART line and your rolling stock would have to be phased out more quickly

highdef

cgcsb wrote: »

The loses aren't the main reason. For dc the substations have to be closer together a long the route, every 2 or 3km. With ac the substations can easily be 25km apart

Are they really that close? The only one I'm aware of on the north side is at Bayside. Where are the others along the Northside?

L1011

Last Stop wrote: »

I don’t think it has to be ac. Given the most likely line to be electrified is quad track they could have an up down up down configuration instead of the current up up down down.

The first line to be electrified is Maynooth. Hazelhatch is only second.

Kevtherev1

Article published in relation to Transport in the 2020 Budget. Confirming funding to build the Pelletstown train station. Continuing Green Line capacity enhancement and metrolink costs.


https://www.breakingnews.ie/ireland/dublin-to-get-new-train-station-and-longer-luas-trams-955902.html

LXFlyer

Kevtherev1 wrote: »

Article published in relation to Transport in the 2020 Budget. Confirming funding to build the Pelletstown train station. Continuing Green Line capacity enhancement and metrolink costs.


https://www.breakingnews.ie/ireland/dublin-to-get-new-train-station-and-longer-luas-trams-955902.html

Good luck to anyone trying to board a train at Pelletstown inbound during the morning peak until the new DART rolling stock arrives which at this rate could be 5 years away.

Ludicrous to even think of opening it until the line is electrified and rolling stock delivered. Or maybe only serve it off-peak until that happens.

CatInABox

LXFlyer wrote: »

Good luck to anyone trying to board a train at Pelletstown inbound during the morning peak until the new DART rolling stock arrives which at this rate could be 5 years away.

Ludicrous to even think of opening it until the line is electrified and rolling stock delivered. Or maybe only serve it off-peak until that happens.

At least the bridge will connect both sides of the river.