DART+ (DART Expansion)

Lord Glentoran

bk wrote: »

To be clear, you are talking about spending 2 Billion extra just to reduce a journey time by a few minutes!

So nothing about increasing capacity for a projected population increase, to create a sustainable economy away from boom/bust?

This is why it has taken 45 years since the Dublin Rail Rapid Transit Study to get this off the blocks. Parts of Official Ireland need to permanently wake up from their dreaming of keeping things as they are.

ncounties

I’m always weary of any argument related to infrastructure that states it’ll only save a handful of minutes. It’s a handful of minutes, multiplied by the daily ridership, multiplied by business days per year, multiplied by the useful life of the line. That’s the benefit.

bk

Lord Glentoran wrote: »

So nothing about increasing capacity for a projected population increase, to create a sustainable economy away from boom/bust?

To be clear, the D+ plan seems to offer the exact same number of DARTs per hour (and thus capacity) on each of the lines in question as the DU plan did.

The D+ plan will be offering triple the capacity on each of these lines. That is a massive increase in capacity and will completely open up West and North Dublin.

DU offered no increase in capacity above and beyond the D+ plan. The only real difference, is under the D+ plan, some folks for some journeys will need to change once to complete their journey.

And 2 Billion extra will buy you a lot more capacity if spend on other lines more badly needed.

liamog

bk wrote: »

To be clear, you are talking about spending 2 Billion extra just to reduce a journey time by a few minutes!

No what I'm saying, is that it shouldn't be included in the pro's and con's list for any particular option. It's not a benefit or drawback of any of the options, it's simply a measurable difference.

The measure should be journey times by cost, the mechanism used to get their should be immaterial.

bk

liamog wrote: »

No what I'm saying, is that it shouldn't be included in the pro's and con's list for any particular option. It's not a benefit or drawback of any of the options, it's simply a measurable difference.

To be honest with you, the way you are wording it (about it taking from bus/Metro), isn't what the report is looking at.

The report looks at how many people will use all the different forms of transport from the areas in question for each of the proposed solutions. Because they are looking at the big picture of increasing public transport in all it forms.

It found that full DU + Bus/Tram/Metro would have 173,300 boardings versus D+ + Bus/Tram/Metro would have 170,900 boardings from the areas in question.

So the question really is, are those 2,400 extra boardings (0.4%) really worth 2 Billion extra? And can that 2 Billion extra be better used elsewhere?

Also you claimed people will be slower by bus. Obviously that isn't the case, no one is going to take a bus if it is slower then D+. They would only take the bus if it is faster then D+ surely. Now for a very small niche of people, those 2,400, DU might have offered a faster journey to their particular destination then a bus. But again cost is a factor.

liamog

bk wrote: »

To be honest with you, the way you are wording it, isn't what the report is looking at.

The report looks at how many people will use all the different forms of transport from the areas in question for each of the proposed solutions.

It found that full DU + Bus/Tram/Metro would have 173,300 boardings versus D+ + Bus/Tram/Metro would have 170,900 boardings.

So the question really is, are those 2,400 extra boardings (0.4%) really worth 2 Billion extra? And can that 2 Billion extra be better used elsewhere?

Also you claimed people will be slower by bus. Obviously that isn't the case, no one is going to take a bus if it is slower then D+. They would only take the bus if it is faster then D+ surely. Now for a very small niche of people, those 2,400, DU might have offered a faster journey to their particular destination then a bus. But again cost is a factor.

Those claims and wording are from the report not myself. That's why I'm questioning them. The report is basically saying one pro of the Dart+ project is it's not as good as DartU so passengers will need to use other modes of public transport.

Dart+ clearly has a better cost benefit ratio than DartU, but adding pro's and con's like that looks like spin to add weight to a particular option.

bk

ncounties wrote: »

I’m always weary of any argument related to infrastructure that states it’ll only save a handful of minutes. It’s a handful of minutes, multiplied by the daily ridership, multiplied by business days per year, multiplied by the useful life of the line. That’s the benefit.

Sure and the report recognises this. The full DU plan is given a higher economic return then D+, because of factors like this. It is just the much higher construction cost swallows up this economic benefit, giving it a low cost benefit to cost ratio to D+ (though still very good on it's own).

Though I would like to see a BCR comparing the DU tunnel section to lets say the Green line Metro upgrade + a South West Metro spur.

The good thing about the D+ plan, is it doesn't stop them from adding the tunnel in future to grab that benefit.

The one issue I've always seen with the full DU plan, is the big price tag up front, 4+ Billion, ouch.

The nice thing about the D+ plan, is that it is not only cheaper, but it allows them to break down into smaller big sized chunks. 500m for trains, 200m for electrification of Maynooth line, 100m for Spencer Dock station, etc. And it is all stuff that needed to be done for DU anyway.

It is much easier to sneak under the radar with the public then. Like the intercity Morotways, they cost 10+ Billion, but you never heard them say that. It was 400million for this 100km stretch of motorway, etc. It didn't sound so scary.

Once D+ is complete. Now the tunnel section won't cost 4 Billion, it will be what sounds like a more reasonable 2 Billion. Hopefully people will say, great, that is a billion cheaper then the recently opened and great Metrolink, lets do it.

Would I loved to have had DU ten years ago, of course I would. But having read through the reports, this looks to be really great and smart plan IMO.

lucernarian

bk wrote: »

Hueston is relatively easy and cheap, they own all the land. Connolly will require lots of CPO'ing and angry home owners.

Having said that, I should point out that the 4 tracking was based on the "Do Minimum" scenario, where nothing was done north of Connolly and it remained a bottleneck for the Northern line. Basically under this scenario they found even with quad tracking, you could only fit two extra DARTs per hour because of the issues at Connolly.

2 extra DARTs not worth it for the large cost involved in CPOing, etc.

Having said that, with the D+ plans, new Spencerdock station, etc. is done, then quad or triple tracking might then make a lot more sense.

That is the most inane thing, the while point of adding an extra track (does NOT have to be 2 extra tracks) was to allow the feasibility of extended services to Drogheda, a 1-hourly enterprise, and 5 minute darts to happen with DU in the first place. Anyone could tell one can't funnel 4 tracks easily into the station layout at Connolly, and opening the likes of Spencer dock is exactly why a third track needs to happen if there are to be any increased services on the northern line. For the modality split and planned frequency of services, 3 tracks to Clongriffin would get 95% of what is needed for the longish term and at a cost under €300 million based on that figure once quoted by Irish Rail. Never mind shaving 10 minutes off enterprise and future semi-express type dart journeys to Donabate and beyond.

The rest of the suggestions in the report are pragmatic, but this is a gaping hole they've overlooked.

Edit: the DU plan and indeed Dart+ can't work out that well if they see the need to have quad track all the way to heuston (good luck with the dual carriageway built right beside/over it) and not apply the same logic to Connolly.

Brian CivilEng

I find this plan exciting, because there is a good chance of it actually going ahead. As bk said above, it allows the entire project to be broken down into a series of smaller projects, each with their own lower costs and benefits. Plus a minor issue holding up construction in one suburb isn't going to delay the roll out of the entire project.

I am also positive about the fact that nothing in the plan precludes DART Underground from being built later. In fact it enhances the chances of it being built, as you would imagine with a tripling of DART usage Irish Rail would find themselves in a better position financially.

Don't let the great be the enemy of the good. If we get all of Metrolink, DART+, Finglas Luas and Bus Connects all built we will be left with a public transport network for Dublin to be proud of.

Brian CivilEng

My own view of four tracking the northern line is possibly biased as I live on a street in Raheny which would require properties to be purchased and demolished (my own home is safe). But with that disclaimer, I don't think it is the best solution. There is a separate rail needs study being carried out, and I believe that it will recommend a new high speed line from Belfast to Dublin. Taking the inter-city traffic from the northern line and leaving it for just DART and commuter services should reduce the capacity issues.

riddlinrussell

Brian CivilEng wrote: »

My own view of four tracking the northern line is possibly biased as I live on a street in Raheny which would require properties to be purchased and demolished (my own home is safe). But with that disclaimer, I don't think it is the best solution. There is a separate rail needs study being carried out, and I believe that it will recommend a new high speed line from Belfast to Dublin. Taking the inter-city traffic from the northern line and leaving it for just DART and commuter services should reduce the capacity issues.

Agreed on the need for a high speed line, I'd expect possibly a recommended route that passes under the city to Heuston (possible stop at Cross Guns?) But the expense of that project would be fairly steep. I can see at a minimum 3 tracking sections of the northern line no matter the grief it will cause, because a separate HS line is a very long term prospect unless Ireland unifies and the EU/UK are providing some sweet unification bonuses

Pete_Cavan

There is a separate team looking at DART+ coastal (existing) route so I'm sure they will explore options on the Northern Line in more detail. I can't see it being feasible to add tracks aloneside the existing tracks. Between Killester and Raheny is in a cutting which can't be easily widened and houses right up to the top of the cutting on either side. To fit in the tracks and everything else they need (drainage, cabling, signalling, etc.) and allowing working space for construction with sufficient spacing for the existing tracks to remain operational, they would have to CPO every property along one side. That is too contentious and would likely face insurmountable opposition, nevermind the enormous cost. I don't see how adding one track would be easier than two. You still have much the same space requirement allowing for construction, two metres less for tracks in still going to require CPOing the whole property.

I think the best way to increase commuter capacity on the Northern Line is to use big trains. Double decker trains are common on the continent and are not much higher than standard trains. Raising a few bridges might be needed but that is a small enough job, particularly when you consider that the bridge would have to be widened anyway if adding more tracks.

MJohnston

I don't mean this in a confrontational way but can someone point me to where the aforementioned houses are that prevent the Northern Line being widened?

I see a lot of back gardens for sure, but even in places where that's true I see a buffer either side of the existing tracks that seems enough to make a widening possible.

To me it seems like the bigger problem is there's no way to widen the line without closing the Northern Line for a significant amount of time.

lucernarian

Brian CivilEng wrote: »

My own view of four tracking the northern line is possibly biased as I live on a street in Raheny which would require properties to be purchased and demolished (my own home is safe). But with that disclaimer, I don't think it is the best solution. There is a separate rail needs study being carried out, and I believe that it will recommend a new high speed line from Belfast to Dublin. Taking the inter-city traffic from the northern line and leaving it for just DART and commuter services should reduce the capacity issues.

It doesn't need quad tracking to achieve almost the same outcomes as 3 tracks... Are you reading what I posted at all... This vastly reduces the need for demolitions except on the approach to Howth Junction.

Pete_Cavan

MJohnston wrote: »

I don't mean this in a confrontational way but can someone point me to where the aforementioned houses are that prevent the Northern Line being widened?

I see a lot of back gardens for sure, but even in places where that's true I see a buffer either side of the existing tracks that seems enough to make a widening possible.

To me it seems like the bigger problem is there's no way to widen the line without closing the Northern Line for a significant amount of time.

The "buffer either side of the existing tracks" is a several metre high embankment from south of Killester to north of Raheny. To add more tracks, you need to dig out the embankment and to do that you need space for large plant to operate. Think large excavators digging out the ground and multiple large dumper trucks removing it and driving routes, turning circles, etc. for them. You also need to build a new embankment or retaining wall which will require more space. All this heavy construction work will have to take place with a sufficient buffer from the existing operational tracks. At the stations, the new track(s) would have to go behind the station which remains live so further back from the existing tracks. If doubt all this can be practically done with only taking gardens, and even if it could, the new embankment/retaining wall would be starting at the back wall of the houses. Every house along the tracks on whichever side you want to add tracks would realistically have to be CPOed.

Pete_Cavan

lucernarian wrote: »

It doesn't need quad tracking to achieve almost the same outcomes as 3 tracks... Are you reading what I posted at all... This vastly reduces the need for demolitions except on the approach to Howth Junction.

That is not true. 3 tracks would require much the same work and expense as 4.

MJohnston

Pete_Cavan wrote: »

The "buffer either side of the existing tracks" is a several metre high embankment from south of Killester to north of Raheny. To add more tracks, you need to dig out the embankment and to do that you need space for large plant to operate. Think large excavators digging out the ground and multiple large dumper trucks removing it and driving routes, turning circles, etc. for them. You also need to build a new embankment or retaining wall which will require more space. All this heavy construction work will have to take place with a sufficient buffer from the existing operational tracks. At the stations, the new track(s) would have to go behind the station which remains live so further back from the existing tracks. If doubt all this can be practically done with only taking gardens, and even if it could, the new embankment/retaining wall would be starting at the back wall of the houses. Every house along the tracks on whichever side you want to add tracks would realistically have to be CPOed.

But why? I'm sure gardens would have to be CPO'd, but what you've said there doesn't seem especially borne out by the physical reality.

Equium

A small point in the grand scheme of things, but I would hope and imagine that a higher standard of station design will be forthcoming. The Option B location in particular offers IE/IR a fantastic opportunity to make use of air rights above the tracks for commercial/residential development right in the heart of the Docklands.

Brian CivilEng

MJohnston wrote: »

I don't mean this in a confrontational way but can someone point me to where the aforementioned houses are that prevent the Northern Line being widened?

I see a lot of back gardens for sure, but even in places where that's true I see a buffer either side of the existing tracks that seems enough to make a widening possible.

To me it seems like the bigger problem is there's no way to widen the line without closing the Northern Line for a significant amount of time.

Between Raheny and Kilbarrack there are points where the gap between back walls of houses each side of the line is 20m. Combined with the track being in a cutting. On the Kildare route project, the cross section was about 22m fence to fence on the flat.

MJohnston

Brian CivilEng wrote: »

Between Raheny and Killester there are points where the gap between back walls of houses each side of the line is 20m. Combined with the track being in a cutting. On the Kildare route project, the cross section was about 22m fence to fence on the flat.

By "back walls of houses" do you mean their boundary walls? Because I genuinely don't see where you mean!

lucernarian

Pete_Cavan wrote: »

That is not true. 3 tracks would require much the same work and expense as 4.

Irish rail said ~300 million for 3 and something like 850 million for 4... Where's your sources?

Brian CivilEng

MJohnston wrote: »

By "back walls of houses" do you mean their boundary walls? Because I genuinely don't see where you mean!

No I mean physical walls of houses. Extensions yes, but part of the building. Again, my disclaimer is that I live on one of these streets so I may be biased. Look at Belmont Park to Foxfield Grove.

lucernarian

MJohnston wrote: »

I don't mean this in a confrontational way but can someone point me to where the aforementioned houses are that prevent the Northern Line being widened?

I see a lot of back gardens for sure, but even in places where that's true I see a buffer either side of the existing tracks that seems enough to make a widening possible.

To me it seems like the bigger problem is there's no way to widen the line without closing the Northern Line for a significant amount of time.

Yeah, the options to develop this while using minimal land take, even for 3 tracks, is almost horrifying. That's the real issue with the work, not the land take.

Pete_Cavan

MJohnston wrote: »

But why? I'm sure gardens would have to be CPO'd, but what you've said there doesn't seem especially borne out by the physical reality.

There are many houses less than 30m from the existing tracks. That is not a lot of space to operate large plant. You probably need 3m buffer from the operating tracks. You will need 10m for two tracks, plus another few metres for embankment/retaining wall. At the stations, 8m or more is taken up with platforms, ramps etc. which are need to remain. It may be possible that some properties would be left with up to 10m of a garden but for many, they would have little or nothing left. I doubt they'd be allowed to CPO a full garden and leave the house which is seriously devalued, they would probably be made but the whole lot.

Even if possible to leave the houses, you have a long linear work site along the tracks with the only access at the bridges crossing the tracks which is not practical. The excavators/trucks cant operate on the embankment, they need to be on level ground which is the gardens. Most of the gardens seem to be less than 15m long, you would need all of that. You then need to dig out the embankment while keeping back from the operational tracks, remove all the material from the site and build replacement embankment/retaining walls in such a way to avoiding subsidence to the houses. The trucks once loaded probably can't continue straight on as that is where the excavation is, they would need to turn or reverse out. It really isn't practical from any point of view.

Pete_Cavan

lucernarian wrote: »

Irish rail said ~300 million for 3 and something like 850 million for 4... Where's your sources?

Where's your sources? Unless you have a link to support, that means nothing. Even if it was said by someone in Irish Rail, it needs context, I mean is the 4 tracks an additional track on either side or two additional on the same side?

MJohnston

Pete_Cavan wrote: »

There are many houses less than 30m from the existing tracks. That is not a lot of space to operate large plant. You probably need 3m buffer from the operating tracks. You will need 10m for two tracks, plus another few metres for embankment/retaining wall. At the stations, 8m or more is taken up with platforms, ramps etc. which are need to remain. It may be possible that some properties would be left with up to 10m of a garden but for many, they would have little or nothing left. I doubt they'd be allowed to CPO a full garden and leave the house which is seriously devalued, they would probably be made but the whole lot.

Even if possible to leave the houses, you have a long linear work site along the tracks with the only access at the bridges crossing the tracks which is not practical. The excavators/trucks cant operate on the embankment, they need to be on level ground which is the gardens. Most of the gardens seem to be less than 15m long, you would need all of that. You then need to dig out the embankment while keeping back from the operational tracks, remove all the material from the site and build replacement embankment/retaining walls in such a way to avoiding subsidence to the houses. The trucks once loaded probably can't continue straight on as that is where the excavation is, they would need to turn or reverse out. It really isn't practical from any point of view.

So the 'why' essentially boils down to not being able to close the line while working on the widening?

I'm just saying that it seems perfectly practical to add a single extra track without having to CPO much more than a few metres of some back gardens IF you accept that the line will have to close for some period.

MJohnston

Brian CivilEng wrote: »

No I mean physical walls of houses. Extensions yes, but part of the building. Again, my disclaimer is that I live on one of these streets so I may be biased. Look at Belmont Park to Foxfield Grove.

Right but that's just one specific spot, and I'm sure there are a few more of them in various places along the line. It wouldn't have to be "every house along the tracks on whichever side you want to add tracks" as someone else said before.

AngryLips

Pete_Cavan wrote: »

I think the best way to increase commuter capacity on the Northern Line is to use big trains. Double decker trains are common on the continent and are not much higher than standard trains.

This does nothing to solve the problem on the northern line, which is the need to separate out the direct intercity services from the suburban services.

Brian CivilEng

MJohnston wrote: »

Right but that's just one specific spot, and I'm sure there are a few more of them in various places along the line. It wouldn't have to be "every house along the tracks on whichever side you want to add tracks" as someone else said before.

I've been messing around on AutoCAD, the problem is you need a pretty straight corridor so the pinchpoints will inform the alignment. If you move the track to the north to avoid houses on the south at one point, you might not be able curve the track back in time to avoid houses on the south.

This is pretty crude, and I don't have access to the OS map tiles in .dwg format (if anybody has and wants to send them my way...), had to use an aerial photo but I make it six houses definitely clipped by the track, and another 20 or so that would lose most of their gardens. The White line is the current centreline of the track (as best I could make out), and each coloured line is offset 2.5m from the next. So the full corridor is 25m.

LXFlyer

As I have posted many times, in order to effectively operate the inner stopping DART service operating every 10 minutes, the outer semi-fast DART, and an hourly Enterprise, an overtaking facility is needed between north of Clontarf Road and just before Raheny Station.

That will allow for an outer DART or Enterprise to overtake a stopping DART at line speed. Otherwise the outer DART/Enterprise will continue to crawl at pedestrian speeds to Clongriffin.

Loops at Clongriffin in both directions would further assist in the ability to overtake.

The whole line does not need three/four tracks. Just between north of Clontarf Road and Raheny.