DART+ (DART Expansion)

Last Stop

Pete_Cavan wrote: »

Better cancel Metrolink so!

You’re either trolling or completely contradicting yourself. :rolleyes:

bk

Last Stop wrote: »

Let me clarify my point AGAIN.
It would incredibly foolish and short sighted for Irish Rail to build shorter station boxes which could only handle 4 car DARTs as was suggested when there are several other ways to reduce the price of DU.
Whether or not they choose to run intercity trains through the tunnel is frankly irrelevant but why would they restrict themselves from having that option in the future?
Personally, I see no reason why they wouldn’t run an hourly Cork-Belfast train though the tunnel along with 5 minute DARTs. This would still be well below the capacity of the tunnel. With quad tracking either side, it would work just fine.

It would be crazy to spend hundreds of millions more to satisfy some fantasy of running trains to the airport, when there is very little chance of it ever being used as such and no demand from the public for it to happen.

I don't know why some people are so enamoured with trying to mix different services on the same line, increasing cost and complexity and ending up with an inferior system.

No other European country does this. London doesn't try and run intercity trains through London Underground, instead it gets it's own tunnel, thus Crossrail. Paris the same with RER. Berlin, has 3 separate sets of tracks, one for each of S-Bahn (DART), commuter and intercity.

Hell we have even seen the success of keeping it simple with Luas here. Each Luas line individually carries more passengers then the DART, despite having much smaller trams and street running, thanks to the simplicity of the system and high frequency.

I really hope we don't go repeating the mistakes of DART with Dart Underground. DU needs to be a high quality mass transit system. Simple and high frequency.

Last Stop

bk wrote: »

It would be crazy to spend hundreds of millions more to satisfy some fantasy of running trains to the airport, when there is very little chance of it ever being used as such and no demand from the public for it to happen.

I don't know why some people are so enamoured with trying to mix different services on the same line, increasing cost and complexity and ending up with an inferior system.

No other European country does this. London doesn't try and run intercity trains through London Underground, instead it gets it's own tunnel, thus Crossrail. Paris the same with RER. Berlin, has 3 separate sets of tracks, one for each of S-Bahn (DART), commuter and intercity.

Hell we have even seen the success of keeping it simple with Luas here. Each Luas line individually carries more passengers then the DART, despite having much smaller trams and street running, thanks to the simplicity of the system and high frequency.

I really hope we don't go repeating the mistakes of DART with Dart Underground. DU needs to be a high quality mass transit system. Simple and high frequency.

But you wouldn’t be spending hundreds of millions more, you would be building a system designed to cater for longer trains which is a sensible investment in terms of increased capacity in the future.
Again this is not like putting an intercity train in London Underground but more akin to like you said crossrail.
The reason for DARTs current low frequency as you well know is the presence of the level crossings in the southern line. If these were removed, 5 minute DARTs would be possible. This would completely outstrip Luas in terms of capacity.
Running 1 intercity train per hour would have a minimal effect on the capacity of the tunnel but would increase the functionality of the system.

Pete_Cavan

Last Stop wrote: »

You’re either trolling or completely contradicting yourself. :rolleyes:

You raised CPOing 70 apartments as if it is something that prevents a DU station at Tara Street. I was pointing out to you that those apartments are being CPOed as part of Metrolink and will be demolished under that project, long before DU. I can only assume that you are trolling at this point.

Last Stop

Pete_Cavan wrote: »

You raised CPOing 70 apartments as if it is something that prevents a DU station at Tara Street. I was pointing out to you that those apartments are being CPOed as part of Metrolink and will be demolished under that project, long before DU. I can only assume that you are trolling at this point.

No I didn’t raise the CPOing of 70 apartments as something that prevents DU. I raised the diversion of the sewer as something that prevents DU at Tara st.
Again I’ll point out that the fact that Metrolink are willing to CPO 70 properties (say 300k an apartment is €21m) suggests that the sewer diversion is either more expensive or technically not feasible. This means that you couldn’t divert it for a DU station here either!! The fact that the apartments are being demolished has no effect on the location of a DU station regardless of whether they are CPOed as part of Metrolink or DU.
This means that there will not be the potential for a cut + cover station at Tara which means that shorting the tunnel and removing a satiation as you suggested will not reduce the costs. Therefore the option of a route via SSG and GCD with cut + cover stations at both will likely be cheaper despite the increased length of tunnel!!!

Pete_Cavan

Last Stop wrote: »

No I didn’t raise the CPOing of 70 apartments as something that prevents DU. I raised the diversion of the sewer as something that prevents DU at Tara st.
Again I’ll point out that the fact that Metrolink are willing to CPO 70 properties (say 300k an apartment is €21m) suggests that the sewer diversion is either more expensive or technically not feasible. This means that you couldn’t divert it for a DU station here either!! The fact that the apartments are being demolished has no effect on the location of a DU station regardless of whether they are CPOed as part of Metrolink or DU.
This means that there will not be the potential for a cut + cover station at Tara which means that shorting the tunnel and removing a satiation as you suggested will not reduce the costs. Therefore the option of a route via SSG and GCD with cut + cover stations at both will likely be cheaper despite the increased length of tunnel!!!

Complete and utter nonsense. Your train of logic is deeply flawed. There is no correlation between CPOing the apartments and avoiding the sewer. The alignment means that the apartments have to be demolished and that the sewer wasn't interfered with. One was an unavoidable expense, there other didn't even materialise, it wasn't a case of either/or and they went for the cheaper option.

If you honestly believe that building a 25% longer tunnel, double the length of stations and an extra station is likely to be cheaper than you are delusional. And don't bring up again "your" cost savings of a single bore tunnel, a detailed engineering report will determine if that is possible and if it is, it will apply to all tunnel routes.

Last Stop

Pete_Cavan wrote: »

Complete and utter nonsense. Your train of logic is deeply flawed. There is no correlation between CPOing the apartments and avoiding the sewer. The alignment means that the apartments have to be demolished and that the sewer wasn't interfered with. One was an unavoidable expense, there other didn't even materialise, it wasn't a case of either/or and they went for the cheaper option.

If you honestly believe that building a 25% longer tunnel, double the length of stations and an extra station is likely to be cheaper than you are delusional. And don't bring up again "your" cost savings of a single bore tunnel, a detailed engineering report will determine if that is possible and if it is, it will apply to all tunnel routes.

Eh have you read the Metrolink Tara St report? One of the options considered was moving the station further south but this was ruled out mainly due to the sewer! Like I said it must be a pretty difficult sewer to divert if they are going to spend over €20m on CPO instead.
The use of cut + cover is a multiple cheaper than a mined station option so yes I do believe it’s going to be cheaper.
Look at Townsend st again: there simply isn’t the fave for even a mined station as there is nowhere to access it. DU is at least 15 years away and by that stage, Metrolink will be built and the sites above sold for redevelopment.
And regarding the use of a single bore tunnel, there already is a detailed engineering report completed as part of Metrolink, and seeing as they went for single bore, it is logical to expect DU to do the same...

Pete_Cavan

Last Stop wrote: »

Eh have you read the Metrolink Tara St report? One of the options considered was moving the station further south but this was ruled out mainly due to the sewer! Like I said it must be a pretty difficult sewer to divert if they are going to spend over €20m on CPO instead.

The report describes the sewer as "an important constraint", and doesn't make an estimate on cost. The station box for the chosen location is shown extending under Townsend Street so it is quite possible it will impact on the sewer. And the choice was not "spend over €20m on CPO instead", all other options would incur significant CPO costs as well, you can't equate the cost of CPOing the apartments with the cost of moving the sewer.

The use of cut + cover is a multiple cheaper than a mined station option so yes I do believe it’s going to be cheaper.
Look at Townsend st again: there simply isn’t the fave for even a mined station as there is nowhere to access it. DU is at least 15 years away and by that stage, Metrolink will be built and the sites above sold for redevelopment.

I accept that a station at Tara Street may not work. I believe it to be a better location for the interchange. Knocking 1km off the tunnel and dropping a station would yield significant savings, far greater than dealing with a sewer at one location.

And regarding the use of a single bore tunnel, there already is a detailed engineering report completed as part of Metrolink, and seeing as they went for single bore, it is logical to expect DU to do the same...

That is not logical at all. It is a completely different tunnel, with a completely different set of constraints for a completely different system with completely different rolling stock. DU will be closer to Crossrail which is twin bore tunnels.

CatInABox

Last Stop wrote: »

Eh have you read the Metrolink Tara St report? One of the options considered was moving the station further south but this was ruled out mainly due to the sewer! Like I said it must be a pretty difficult sewer to divert if they are going to spend over €20m on CPO instead.
The use of cut + cover is a multiple cheaper than a mined station option so yes I do believe it’s going to be cheaper.
Look at Townsend st again: there simply isn’t the fave for even a mined station as there is nowhere to access it. DU is at least 15 years away and by that stage, Metrolink will be built and the sites above sold for redevelopment.
And regarding the use of a single bore tunnel, there already is a detailed engineering report completed as part of Metrolink, and seeing as they went for single bore, it is logical to expect DU to do the same...

Don't agree with all your thoughts Last Stop, but I think you're broadly correct here.

The Metrolink project has been one long, in-depth presentation on how to minimise risk and complexity in a project, and the example of the College Gate apartments is probably the prime example. The NTA has chosen to go through the CPO process for 70 apartments, despite the optics of destroying homes during a housing crisis, all to avoid dealing with the two sewers on Townsend St.

I can't imagine that a Dart Underground project will ignore the learnings of Metrolink either, the main one being "the simpler, the better". I say that they might look at Tara St, but conclude that there's simply no room available in the area (other than a dig that crosses into the Liffey, but again, that'd be ruled out by being more complex).


On the other hand, I think SSG would be looked on favourably by the planners. I think a station along the south side of the park would be the option that they go for, as it would allow them to dig without touching Traders Arch or draining the pond, both of which were bones of contention in the original plans. They don't really care about having "easy" interchange here either (if they did then they would have done more with integrating Metrolink with the Luas already), so having station on each side of the green would be "acceptable". Not ideal, but acceptable.

Irish Rail still consider Pearse St as an integral part of any DU plan as well, as recently as last year they got the ABP to reject proposals on Sandwith St saying a station was going in there. Hilariously, that means that the owner can't develop the site, which also means that they're getting hit with levies for not developing the site.

Last Stop

Pete_Cavan wrote: »

The report describes the sewer as "an important constraint", and doesn't make an estimate on cost. The station box for the chosen location is shown extending under Townsend Street so it is quite possible it will impact on the sewer. And the choice was not "spend over €20m on CPO instead", all other options would incur significant CPO costs as well, you can't equate the cost of CPOing the apartments with the cost of moving the sewer.

I accept that a station at Tara Street may not work. I believe it to be a better location for the interchange. Knocking 1km off the tunnel and dropping a station would yield significant savings, far greater than dealing with a sewer at one location.

That is not logical at all. It is a completely different tunnel, with a completely different set of constraints for a completely different system with completely different rolling stock. DU will be closer to Crossrail which is twin bore tunnels.

The cost and bad publicity of the apartments were chosen over diverting the sewer. Otherwise they would have moved the station further south. If they could have diverted it I suspect they would have so I honestly doubt that DU will be able to touch it regardless of cost.

The tunnel configuration report even includes DU in the title. The 2 biggest concerns regarding the tunnel will be cost and safety. A single bore is much cheaper than twin bore as it requires no cross passages and can be done with one TBM. The safety aspect will be addressed by Mertrolink so while they are completely different systems which I’m not denying, there will be lots of learnings which can be gained

CatInABox

Pete_Cavan wrote: »

The report describes the sewer as "an important constraint", and doesn't make an estimate on cost. The station box for the chosen location is shown extending under Townsend Street so it is quite possible it will impact on the sewer. And the choice was not "spend over €20m on CPO instead", all other options would incur significant CPO costs as well, you can't equate the cost of CPOing the apartments with the cost of moving the sewer.

The station box construction zone will take up less than half of Townsend St, but will almost certainly avoid touching the trunk sewer. Most likely, any works involving the sewer would only involve buttressing it.

The report also says that "Irish Water unlikely to agree diversion or any interference with sewer." Water companies hate any disruption to trunk sewer.

Pete_Cavan wrote: »

I accept that a station at Tara Street may not work. I believe it to be a better location for the interchange. Knocking 1km off the tunnel and dropping a station would yield significant savings, far greater than dealing with a sewer at one location.

It's not just one location though, you've got to find another route for the sewer. That would involve significant lengthy closures on Tara St, probably Pearse St, and several more.

Pete_Cavan

The position of the sewer can be seen in appendix A of this document:

https://www.google.ie/url?sa=t&source=web&rct=j&url=http://www.dublincity.ie/AniteIM.WebSearch/Download.aspx?ID=559584&ved=2ahUKEwjv9oXkpKrjAhXQN8AKHV6dDQUQFjAXegQIARAB&usg=AOvVaw2HglBpHsoRct92M5z6oVom

According to the position of the station on the Metrolink PR Report, the retaining wall of the station is directly under it with no space to move it away. I would be amazed if Metrolink construction doesn't interfere with it given they will need additional working space.

Like I said, if there isn't space for a station there I can fully accept that. I don't see the sewer as preventing it, sewers are pumped temporarily to bypass a section while works take place rather than redirecting along another route.

D.L.R.

Don't see the issue with shorter Darts in the tunnel, or even Metro sized, once we have high frequencies. Dublin doesn't really need a massive mainline tunnel it just needs 2-3 metro tunnels.

The main snag for a high frequency Metro-style DU is the Northern line. An easy solution is to run it to Maynooth instead, and keep the existing Bray-Howth route with its established longer train/lower freq profile. There's less intercity traffic on the Maynooth route, and you have 4 tracks out of Dublin to match the 4 tracks planned out of Heuston. Equally, the Northern and Southeastern lines are both constrained to two-track for the foreseeable future, so it makes sense to keep them together.

I read something in the report about new platforms west of 5-6-7 @ Connolly, which would help eliminate conflicts there.

The Northern line was a huge gap in the logic of the original DU plan. Just remove it from the equation.

cgcsb

It's likely that something will be done about the Northern line in advance of DU, be that a third track for long distance services or some more complex solution.

The third track would cost relatively little and would accommodate an hourly, or greater service to Belfast, while allowing DARTs to keep he existing tracks for a 5min frequency service if need be.

D.L.R.

cgcsb wrote: »

It's likely that something will be done about the Northern line in advance of DU, be that a third track for long distance services or some more complex solution.

The third track would cost relatively little and would accommodate an hourly, or greater service to Belfast, while allowing DARTs to keep he existing tracks for a 5min frequency service if need be.

That would be good, but I'm sceptical. And while 3 tracks is obviously better than 2, its still not really enough in the long term for one of the busiest lines in the country.

I'll never understand why the route wasn't protected from overdevelopment.

Qrt

D.L.R. wrote: »

That would be good, but I'm sceptical. And while 3 tracks is obviously better than 2, its still not really enough in the long term for one of the busiest lines in the country.

I'll never understand why the route wasn't protected from overdevelopment.

What are the issues with the line’s expansion? Is it just the back gardens backing onto the line thing? Would all the stations have to be demolished and rebuilt?

CatInABox

Qrt wrote: »

What are the issues with the line’s expansion? Is it just the back gardens backing onto the line thing? Would all the stations have to be demolished and rebuilt?

Mainly back gardens that would entirely disappear, and some houses/apartments that create a pinch point. Kilbarrack and Howth Junction the biggest culprits I think. They'd probably need to be CPO'd if it's to be four tracked, maybe even if it's only three tracked.

All the stations would need significant work, but some would be easier than others. Some could actually be built in a new location, and then have the old one removed, such as Killester station. That could be moved 200 metres towards the city and the entrance would then be on a main road, closer to the main shopping area, and on what is to be an orbital route under BusConnects. Right now, it's in a location that's highly unsuitable, it doesn't even have a path wide enough for a small buggy, never mind a wheelchair.

donvito99

Suggestion: inland route via the Airport, Port Tunnel (one bore, the other would have to be bi directional for lorries, other traffic) and CIE yards into Connolly? All Belfast/outer Commuters would be removed from the existing main line at Donabate. Everything south of that point would operate as DART/heavy metro.

Dats me

donvito99 wrote: »

Suggestion: inland route via the Airport, Port Tunnel (one bore, the other would have to be bi directional for lorries, other traffic) and CIE yards into Connolly? All Belfast/outer Commuters would be removed from the existing main line at Donabate. Everything south of that point would operate as DART/heavy metro.

Love the idea of appropriating one of the Port Tunnel bores. We need a seismic shift in Irish politics to get something big done. A 20% Green vote or something

D.L.R.

Using one of the port tunnels is a bit too out there I think, but a tunneled route might be the only practical solution.

You could quad track as far as Clontarf golf club and then tunnel under the north suburbs to the Airport, then come above ground and continue to Drogheda. This would take all long distance traffic off the Northern line. Science fiction though, lets be honest.

donvito99

D.L.R. wrote: »

Using one of the port tunnels is a bit too out there I think, but a tunneled route might be the only practical solution.

You could quad track as far as Clontarf golf club and then tunnel under the north suburbs to the Airport, then come above ground and continue to Drogheda. This would take all long distance traffic off the Northern line. Science fiction though, lets be honest.

I think the tunnel diameter at approx. 10m (usable) would be too tight in any case.

A tunnel (without stations, usually the expensive bit) would probably be cheaper and politically easier than CPOing everyone from Clontarf to Howth Junction.

D.L.R.

donvito99 wrote: »

I think the tunnel diameter at approx. 10m (usable) would be too tight in any case.

A tunnel (without stations, usually the expensive bit) would probably be cheaper and politically easier than CPOing everyone from Clontarf to Howth Junction.

Is there a better example of bad planning than the housing built along the northern line?

That took a certain kind of special.

SeanW

D.L.R. wrote: »

Is there a better example of bad planning than the housing built along the northern line?

That took a certain kind of special.

The same thing is happening along the Maynooth line. Less than a mile from Clonsilla on the City side, new houses etc. are being built right next to the track.

Stephen Strange

D.L.R. wrote: »

Using one of the port tunnels is a bit too out there I think, but a tunneled route might be the only practical solution.

You could quad track as far as Clontarf golf club and then tunnel under the north suburbs to the Airport, then come above ground and continue to Drogheda. This would take all long distance traffic off the Northern line. Science fiction though, lets be honest.

It would probably be cheaper to CPO along existing line and quad track I would assume.

marno21

D.L.R. wrote: »

Is there a better example of bad planning than the housing built along the northern line?

That took a certain kind of special.

What’s even worse is that some of the bridges were built wide enough for 4 tracks. I noticed this one day walking over the Collins Avenue how much space was left underneath the bridge.

L1011

The GNR were preparing for 4 tracking to Howth Junction or so and 1500v DC electrification to Belfast before they were merged in to CIE. Hence there are some very old 4 tracking

SeanW wrote: »

The same thing is happening along the Maynooth line. Less than a mile from Clonsilla on the City side, new houses etc. are being built right next to the track.

Maynooth Line alignment is so awful that any additional capacity that way for higher speed is going to have to be an 11 figure tunnel. There's absolutely no point trying to widen alongside the canal. Even if you somehow were able to remove the canal - never going to happen - it'd still be an awful alignment.

strassenwo!f

CatInABox wrote: »

Don't agree with all your thoughts Last Stop, but I think you're broadly correct here.

The Metrolink project has been one long, in-depth presentation on how to minimise risk and complexity in a project, and the example of the College Gate apartments is probably the prime example. The NTA has chosen to go through the CPO process for 70 apartments, despite the optics of destroying homes during a housing crisis, all to avoid dealing with the two sewers on Townsend St.

I can't imagine that a Dart Underground project will ignore the learnings of Metrolink either, the main one being "the simpler, the better". I say that they might look at Tara St, but conclude that there's simply no room available in the area (other than a dig that crosses into the Liffey, but again, that'd be ruled out by being more complex).


On the other hand, I think SSG would be looked on favourably by the planners. I think a station along the south side of the park would be the option that they go for, as it would allow them to dig without touching Traders Arch or draining the pond, both of which were bones of contention in the original plans. They don't really care about having "easy" interchange here either (if they did then they would have done more with integrating Metrolink with the Luas already), so having station on each side of the green would be "acceptable". Not ideal, but acceptable.

Irish Rail still consider Pearse St as an integral part of any DU plan as well, as recently as last year they got the ABP to reject proposals on Sandwith St saying a station was going in there. Hilariously, that means that the owner can't develop the site, which also means that they're getting hit with levies for not developing the site.

Interesting post.

A key thing here is the need for some really definitive decision about any future for a DART Underground project.

If a project along those lines is not going to happen, in the next, say, 50 years or so (and assuming the metrolink does), then the current metrolink proposal for the city centre is pretty good.

But if something like the original DART Underground idea is going to happen, within say the next 20-30 years or so (and obviously also assuming that the metrolink happens), then it might be better to do something other than building the diversion via Tara Street.

In the scenario that metrolink happens and DART Underground happens, under a broad alternative to the current Swords - Charlemont proposal, the metro could be built along an O'Connell Street - College Green - St. Stephen's Green axis, with the metro and DU projects interchanging at St. Stephen's Green. There would thus be integration between the Maynooth/Dunboyne line trains, and perhaps some PPT trains, with the metro, at Glasnevin and/or Drumcondra. There would be interchange with Hazelhatch trains at St. Stephen's Green, and there would be integration between northern DART line trains and the metro at St. Stephen's Green.

Southside DART line trains would integrate with the metro at Drumcondra/Glasnevin, presumably mostly for people heading to/from locations north.

(Southside DART passengers who wish to travel to locations along the Green LUAS on the southside, and vice versa, could be catered for well by new bus arrangements in the south-east part of the city, aided by all those buses freed up by these new arrangements).

Obviously, exactly the same integration scenario could be achieved by having an interchange between the DU project, and the metrolink, in College Green, which the city is hoping to pedestrianise.

That location - College Green - would have potential passengers piling in from all sides, unlike a severely compromised location like St. Stephen's Green, where at least half of the most effective catchment area is taken up by a 22-acre park, with no commuters.
No need for interfering with trees, or duck ponds, just dig up an area which the city wants to pedestrianise, put in station boxes, cover it over and pedestrianise it, and allow that area to go on having the major public transport function which it has now, and has had for many years.

Overall, the current plan looks fine, if it has definitively been determined that the DU project is not going to happen. It integrates the metro with the Maynooth, Dunboyne and PPT lines in one or sometimes two locations, and it integrates the metro with both the southside and northside DART lines.

But that metro loop via Tara St would probably be unnecessary if Dublin were to decide to go ahead with a DART Underground project.

A problem is that the metro may already be in situ, on that loop via Tara Street, with buildings perhaps unnecessarily demolished - there'd be no need for that in College Green - by the time new plans for a DART Underground project emerge, and will make it more difficult for any DART Underground project to be built.

Zebra3

I think if ML is built and turns out to be a resounding success (I’d expect it to be), with the changes to the Maynooth and Kildare lines, I’d expect a second metro line to be more likely than DU.

strassenwo!f

Zebra3 wrote: »

I think if ML is built and turns out to be a resounding success (I’d expect it to be), with the changes to the Maynooth and Kildare lines, I’d expect a second metro line to be more likely than DU.

The most sensible arrangement I can see for Dublin is the metrolink going initially Swords - Airport -City - Southwest Dublin, with eventually two branches there. (Perhaps Rathmines - Terenure - Rathfarnham - Firhouse (mainly because the initial three of those areas have considerably higher population densities than places like Dundrum and/or Sandyford, or pretty well anywhere on the current Green Line), and Harold's Cross - Kimmage - Walkinstown (because the densities are pretty good, but the opportunities for hoovering up bus passengers are super).

The second metrolink could go Cherrywood/Sandyford to Broadstone and beyond, via a city centre tunnel, with perhaps scope to get another route in there (The N11 and UCD, and beyond, perhaps).

Metro tunnel 1 (Airport/Swords to/from Knocklyon/Walkinstown) meeting metro tunnel 2 (Cherrywood/N11/Broadstone alignment) in St. Stephen's Green, and the DART Underground in College Green.

Metro tunnel 2 (Cherrywood/N11/Broadstone alignment) meeting metro tunnel 1 (Airport/Swords to/from Knocklyon/Walkinstown) at St. Stephen's Green, and the DART Underground at the proposed Christchurch DART station.

That sounds, to me, like the basis for a one-change metro-DART system for very large chunks of Dublin.

CatInABox

The idea that utterly gimping the city centre interchange potential of a project that's on the cards right now, for the slim possibility of slightly improved interchange at some unknown point in the distant future is silly.