DART underground - options

lucernarian

https://www.boards.ie/discussion/comment/120915735#Comment_120915735

I'm not really sure how the "Crossrail Dublin" description ever matched, considering there are longstanding comparisons that could be arguably more comparable and a lot more informative. E.g. The S-Bahn tunnel of Munich, the Leipzig tunnel or the (rather unfortunate) Stuttgart tunnel project, which is probably the most informative all things considered.

Also, the report isn't an official one while the Stormont Executive isn't functional but that's a technicality. As for the functionality of the DART lines, they very much facilitate commuter travel. But I'm confused by what looks like an obfuscation of what CrossRail is, in the Dublin context. CR is a very London-specific thing with extreme costs associated with existing underground lines and a focus on usability at a fairly high cost. In any case, the report has been under the cloud of political difficulties in Northern Ireland and has been for quite a while.

I'm struggling to understand the "long distance commuter train" distinction as the DU proposal is A) a tested one through the RO and a longstanding realisation that capacity is almost maxed out in Dublin terminal stations and B) inherently would unlock moderate commuting potential as well as longer-distance travel. Bonus C) CrossRail facilitates east-west travel through a major city with various destinations on both sides of the project area. Dublin has a sea to the east of it. Doesn't seem like a remotely valid comparison.

bk

Ok as I said earlier, I’ll stop calling it “Crossrail Dublin”, they call it “Cross Dublin Tunnel”.

But it isn’t relevant, they have gone from wanting to build a tunnel that would be DART only, to seemingly wanting to build some sort of Frankenstein tunnel that will have DART’s (maybe), commuter trains and intercity trains in it! That is a very different proposition from what was originally proposed for DU.

Now it seems to me IR themselves don’t even know what sort of tunnel they want to build! The high level strategy for this tunnel seems to be gone, never mind the technical details.

I feel it is a really bad sign for the future of this project!

loyatemu

https://www.boards.ie/discussion/comment/120945634#Comment_120945634

at this stage the timescales are going beyond the end of my life expectancy and/or into the post-climate-apocalypse era so it's hard to engage with the latest strategy in any serious way. It's just another document to add to an already groaning shelf.

bk

https://www.boards.ie/discussion/comment/120945691#Comment_120945691

You perfectly express how I also feel about this project now.

There may well be some Cross Dublin tunnel in some distance future, but not during my lifetime. It looks like Dart Underground is truly dead and gone as a project.

brianc89

I've been saying this for a year - the plans for Dart+ West (at Spencer Dock) are in complete violation of DU. Irish Rail / NTA have been fully aware of this, since they commissioned a report in 2020 (attached) which told them exactly this.

The new station plans are not deep enough to continue a tunnel south under the river, and the tracks are being placed exactly where the TBM was supposed to go. The only way to "maybe" make it work is to move the TBM entrance east, cutting off all freight access to Dublin Port.

Annex-9-3-Docklands-Station-Options-Study-Summary-Report.pdf

Consonata

https://www.boards.ie/discussion/comment/120945786#Comment_120945786

I feel like IÉ did a CBA on DU on the back of a napkin and realised they're never going to get the funding for the project given its poor benefit outlook. This is just another cut in its death by 1000.

Pete_Cavan

https://www.boards.ie/discussion/comment/120945634#Comment_120945634

Irish Rail didn't produce that report. They may have been consulted but that doesn't prevent the authors from putting whatever they wanted into the report. Like with every other thing mentioned in that report, any project which moves to actual consideration will receive a totally different level of scrutiny to assess what is achievable and what isn't. This report is very hypothetical, you shouldn't be getting hung up on what it says about a potential Dublin tunnel.

Pete_Cavan

https://www.boards.ie/discussion/comment/120945786#Comment_120945786

There is little to no chance that tunnelling will start at the eastern end of the tunnel. It would mean heavy works ongoing in the city centre for several years, all materials first being brought into the city centre and all spoil from the tunnel having to be removed from the city centre. A far more logical solution is to tunnel from west to east and only remove the TBM in the Docklands.

Everyone knows DART Underground is dead, any future tunnel will be a completely new project.

brianc89

A4-2-Spencer-Dock-Station-Design-Report.pdf

https://www.boards.ie/discussion/comment/120947557#Comment_120947557

Just to be clear, the same group produced the route options and concept design reports for Dart+ West Spencer Dock. Concept design report attached.

Conclusion from reading these reports..... Irish Rail have knowingly and purposefully killed Dart Underground, with the Dart+ West plans. Any future tunnel will not emerge in the Spencer Dock area. It simply isn't possible anymore.

Report 1 (route options) says:

In order to make the decision on which Option should progress to concept design level, it is crucial to know whether the DART Underground project will be implemented.

Report 2 (concept design) says:

As advised by Iarnród Éireann, the DART Underground project has not been considered in the development of the design for Spencer Dock Station.

D.L.R.

The DU route should be a metro tunnel. That's what Dublin needs and that's the right scale for Dublin. DU was unnecessarily large. We don't need 180m Darts under the city, we need 60m high frequency metros.

Perfectly workable solution to build a metro tunnel from Heuston to Spencer Dock/Connolly as a standalone project with potential future expansion. Plenty of room for a depot around Heuston or the Docks.

Dublin really needs its own governance, the state seems hopelessly confused about what's best for the city. The woefully misguided cross-Dublin tunnel in the new rail plan proves that.

Pete_Cavan

https://www.boards.ie/discussion/comment/120947607#Comment_120947607

DART Underground died 10 years ago when they didn't implement CPOs arising from the RO and developers sought another use for a site which was to be CPOed (the developer even went to court over it and the judgment was that IÉ either implement the CPO then or forget about it, the site wasn't going to be held for them to CPO at some undefined point in the future).

DART Underground has been dead a long time, long before DART+ West. A new tunnel project will be an entirely new design, we have seen that with other concept reports which looked at the tunnel portal on the western side of the city being closer to Heuston than DU proposed.

Forget about DU. New tunnel, entirely new concept, that's the way it has to be.

brianc89

https://www.boards.ie/discussion/comment/120948173#Comment_120948173

Which area do you refer to, regarding CPO? They really need to get their crap together and safe guard a future route. The Docklands, specifically around Spencer Dock, will never have a tunnel entrance/exit now. There's no space.

Ideally, the Clontarf Gold Club might be the best place for a tunnel to emerge and join the Northern line. I don't see where else?

brianc89

https://www.boards.ie/discussion/comment/120948063#Comment_120948063

That's a really interesting point on the length of platforms. Luas is 55m versus Dart of 170m. What about rail gauge?

• Luas, Metro are the same

• Dart, Intercity, Commuter are the same.

• Metro and Dart are different though, right?

AngryLips

https://www.boards.ie/discussion/comment/120948063#Comment_120948063

If it was a metro tunnel, they could probably upgrade the rest of luas red line to metro standard from Heuston westwards ...similar to the plans for luas green line

brianc89

https://www.boards.ie/discussion/comment/120948516#Comment_120948516

There are so many possibilities to improve current network and add East-West capacity that won't cost several / tens of billions.

I hope people, starting on Boards, can accept DU is entirely dead, so we start discussing realistic alternatives.

Pete_Cavan

https://www.boards.ie/discussion/comment/120948449#Comment_120948449

The site in question is at Sandwith Street and was to used for part of the Pearse Street DU station. The only way to safeguard sites is to buy them at whatever price the owner is willing to sell, CPO can't be used unless there is a specific need for the land in the near future.

The DU plan was also based on a Metro station having been built at SSG which isn't happening now. Every aspect of a new tunnel needs to be assessed and designed from scratch.

There is space for a tunnel exit portal at Spencer Dock but there isn't space for a huge construction compound, materials storage area, spoil stockpile, etc. which is required at the launch site. I don't think the DU plan would have worked logistically, if it went ahead it would have had issues which would make the Childrens Hospital team blush.

brianc89

@Pete_Cavan you are either ignoring the point I'm making on Spencer Dock or overlooking it. Check the plans. Review the route options document (relatively short, 20pages or so).

After they lay a 3m thick re-enforced concrete track bed and platforms for Dart+, there will not be space for a tunnel entry/exit point at Spencer Dock. This is a massively significant point regarding any future plans for a tunnel.

Consonata

https://www.boards.ie/discussion/comment/120949117#Comment_120949117

Theres a good chance that the tunnel won't even emerge at Spencer dock. Thats the point. The old route is probably dead and there might only be a deep level station at the Docks

gjim

So the consensus is to ignore the experience of nearly every other city in Europe with decent rail PT - from the largest like Paris and London, to cities around the similar scale or smaller than Dublin like Zurich, Munich, Copenhagen, Salzburg, etc. who all have built tunnels through the centre of their cities to link up legacy heavy rail lines to turn them into the heavy-lifting backbone of their public transport systems. Sure, what would these clowns know about developing a PT rail network?

Running a street tram - the Red Luas - through a tunnel in the city centre is simply not a viable alternative to a tunnel that has the capacity to carry over 20 thousand passengers an hour per direction.

I'm reasonably happy with DART+, ML and Busconnects - as they represent the biggest investment and commitment by any government since the foundation of the state. And in my lifetime, I've seen that such a commitment to spending on roads over a decade or two has transformed Ireland's road network.

But the two biggest flaws with transport 42 are the not extending ML to Sandyford and not building a tunnel to support through-running of DARTs.

The CBA in transport 42 is bollox as well. A bit like Crossrail in London where peak usage is already 50% higher than expected. How anyone could credibly claim that DU would only increase DART patronage by 10%, is beyond me. Being able to to get a DART directly to Stephens Green from as far as out as Hazelhatch from the SW or Drogheda from the North would represent a revolution in PT in Dublin. Especially with the 10s of thousands of new housing units going up along DART SW.

The previous DU plan may or may not go ahead exactly, but something like it HAS TO be built to bring heavy rail suburban/urban PT in Dublin up to scratch. Dublin is not unique - most rail infrastructure around the world was developed in the 19th century and features terminal stations around what was the edges of cities - and this configuration just doesn't support the type of service expected in metro-rail travel in the 21st century. Since the 1970s, cities around Europe realised this and have been correcting the issue by building versions of the DU/Interconnector - but for some reason there has been covert (slyly like with the old RPA) and now overt opposition to doing the same in Dublin. I don't get it.

brianc89

@gjim you've been one of the main people telling me I was wrong regarding Spencer Dock. Do you still think some form of a tunnel can work here, or do you agree with my assessment?...

...Irish Rail are knowingly, purposely and very slyly destroying the 'current' Dart Underground plans with Dart+?

gjim

Brianc, I don’t get the impression you’re qualified as a rail or civil engineer so your opinion of what is feasible is just one of many. No engineering report has examined the subject in depth nor given a qualified opinion one way or the other, so no I don’t share your confidence in your own engineering expertise.

That’s not relevant to my main point which is that the problem Dublin has with poorly sited and poorly positioned terminal heavy rail stations is one shared by almost every other city in Europe if not the world. Every single city in Europe has addressed the problem in the same way - with a heavy rail tunnel - used exclusively for electrified urban/suburban services - through the centers of their cities. IE didn’t pull the idea for DU out of their arses - they simply followed the same pattern used by the cities everywhere else.

The solution works, has been a big success everywhere it’s been tried but apparently the tried tested and obvious solution isn’t appropriate for Dublin - I’m calling boll*x on that.

brianc89

https://www.boards.ie/discussion/comment/120950224#Comment_120950224

Wow, really? Could you not just admit you no longer disagree with me? This doesn't need to descend into a petty argument, just give me some credit after a year telling me I was totally wrong.

I'm not a qualified engineer but I studied Maths and Physics up to Masters level so I'm well able to add 2 plus 2. You don't need to be an engineer to read and understand the extremely detailed reports that have been published.

AngryLips

https://www.boards.ie/discussion/comment/120949151#Comment_120949151

There's land set aside for the now abandoned eastern bypass not so far from Spencer dock.

gjim

You were wrong or right about what? That the DART+ Spenser Dock station makes the DU/interconnector impossible? I disagree with that, so?

What credit do you feel you are due? I'm confused.

Nor do I know why this is important to you and why you're avoiding the actual subject I posted about? That the layout and awkward configuration of heavy rail stations in Dublin reflects a common pattern given the way rail developed in the 19th century. And that cities with a reputation for high quality PT had similar issues with terminal capacity, frequency and throughput and that all of them solved the problem using something like the DU - a heavy electrified rail tunnel under the centre of the city.

brianc89

https://www.boards.ie/discussion/comment/120950358#Comment_120950358

It's important to me because the impact of Dart+ on Spencer Dock fundamentally changes the basic concept of DU. That idea being the creation of 2 distinct commuter Dart lines (Northern line to SW line; Drumcondra line to Bray line).

The impact of that change is massive. Where can a tunnel now emerge?.... Closer to Dublin Port? Then where?...through Fairview to the Northern line? Maybe we keep tunneling all the way to the airport? Or maybe we repurpose one of the Dublin Port tunnels? What will be the cost impact of such a fundamentally different line? Do we abandon commuter services in that line and focus on intercity?

So many questions stem from Spencer Dock. You underestimate the significance.

brianc89

https://www.boards.ie/discussion/comment/120950458#Comment_120950458

@gjim , I'm not looking for a god damn medal.

I want people to acknowledge the fundamentally altered plans, so we can have a super interesting conversation about the impacts and potential solutions of that change.

All I get from you is "I don’t get the impression you’re qualified as a rail or civil engineer".

gjim

Brian, your claim is that it will be impossible to link the northern line to DART SW because of DART+ Spencer Dock? Like I said, I don't agree with that claim, so I still don't know why you feel you're due credit or a pat on the back? Your opinion does not equal fact - and it's not just me, others on this this thread don't seem to agree with that claim. There has been no authoritative report or engineering study to back up your opinion, yet you you feel vindicated in some way? I really don't know where you're going with this.

brianc89

https://www.boards.ie/discussion/comment/120950495#Comment_120950495

The same people who designed Dart+ West made the following reports. They were extremely clear on the impact of Dart+ on DU. Extremely clear.

You don't need to be an engineer to see, it is simply physically impossible to build the Spencer Dock station, connecting to 2 separate Dart lines to the West, while simultaneously maintaining freight access to Dublin Port to the East and having a Metro tunnel emerge in the middle of this and connect to the Northern line.

Report 1 (route options) says:

In order to make the decision on which Option should progress to concept design level, it is crucial to know whether the DART Underground project will be implemented.

Report 2 (concept design) says:

As advised by Iarnród Éireann, the DART Underground project has not been considered in the development of the design for Spencer Dock Station.

A4-2-Spencer-Dock-Station-Design-Report.pdf

Annex-9-3-Docklands-Station-Options-Study-Summary-Report.pdf

Pete_Cavan

The new Spencer Dock station proposed under DART+ will have to have tracks and platforms (services temporarily relocated to the current Docklands station site) to allow for the tunnel portal to connect to the curve to the Northern line. The space proposed for the platforms will need to accommodate the level change to the new deeper station and tunnel portal further south. The actual station entrance building on Mayor Street could probably be retained as a northern entrance to the tunnel station.

If before they were able to adequately design to get the tunnel under the Liffey, through a station at North Wall Quay and then to connect to the northern line, there's no reason why that still can't happen. The geography is the same and none of the main points will have changed (depth of Liffey, NWQ station location, height/location of Northern line, etc.).

Just the Spencer Dock station will have to decommissioned (although most of the main structural elements will likely remain) and services relocated for a year or more. We are probably looking at approx 2050 before this could happen anyway and we need the terminating capacity that Spencer Dock station will create now. Whatever has to be done to the Spencer Dock station, it'll still be cheaper than tunnelling to somewhere else.

gjim

Brian, the sentences you've highlighted simply cannot be interpreted as statements that a Northern line to DART SW tunnel is impossible because of DART+ Spenser Dock. Neither say anything at all about the feasibility of connecting the northern line to DART SW. They are concerned with the construction of DART+ Spenser Dock.

Not considering the DU in the design of this new station was a reasonable approach since DU was taken off the table for consideration until 2042 at the very earliest.

To be honest this is extremely tedious. I accept that you don't believe it's possible - I disagree with your opinion (because that's all it is) - is there anything more to be said?