DART+ (DART Expansion)

gjim

https://www.boards.ie/discussion/comment/119421786#Comment_119421786

If I'm being rude, I'm sorry - I haven't meant to be. But I admit it rubs me up the wrong way when someone repeatedly misinterpreted my position or ignores what I've said by stating "thank you for admitting I'm right and you're wrong".

In any case, there's no need to get upset about what should be purely a technical discussion. I assume that you (like me) want the best for Dublin in terms of rail based PT in the future; we're actually on the same team here even if we're disagreeing about details. So let's just view it as a way to learn more about the plans.

What I've learned is that the base of the foundation for Spencer Dock station is lower than I expected (5.8m below ground level according to the RO docs) and I guess you've learned that it higher than the 10m you believed?

And also that with or without Spencer dock, it's going to be tight either way getting from Hawthorn Av to under the Liffey, given that the tunnel has to level off for more than 150m for the DU station platforms.

I guess we'll continue to disagree on whether Spencer Dock will have to be demolished - I really don't think it does given the details in the revised DU options document which shows the section under the SD site being tunnelled by TBM and not cut and cover. I may be wrong - but I don't think my position is completely unreasonable. I acknowledge your concerns but don't share them, fair?

DoctorPan

https://www.boards.ie/discussion/comment/119422115#Comment_119422115

Howth service are to be a stuttle service from Howth to Howth Junction as per DART + Coastal North. There isn't enough paths for Howth services plus services heading north.

randomname2020

I think you're misunderstanding why SD would be demolished. The tunnel would be done with a TBM, but stations are dug top down via a big hole in the ground - so to have a station at SD 10m below the DART+ West station, the DART+ station would need to be dug up.

This is why the new Dart Underground document states that the new station would need to be "temporarily relocated".

brianc89

https://www.boards.ie/discussion/comment/119424198#Comment_119424198

This is really disappointing but I guess it makes sense, if there really isn't capacity on the line.

But I would wonder - with an appropriate signalling system, could you not run a service from Howth to Spencer? You would reduce pressure on Connolly which is a major goal of these plans.

As a separate discussion, is there merit to discussing additional stations between Howth and Howth Junction? From looking at the map, they seem very far apart. If it has to be a shuttle service, let's maximize the amount of stations on that service...

brianc89

https://www.boards.ie/discussion/comment/119423933#Comment_119423933

You are spot on to be fair. I definitely got hot headed over this, with you in particular!!!

New Spencer Dock platform is "higher than I assumed", but "lower than you assumed". I think the conclusion is that - there are some reasonable doubts as to the feasibility of Dart+ and DU, which are not fully addressed in the RO, but it should be technically feasible.

I still have doubts as to the meaning of "temporarily relocated". I also have doubts about if this would ever happen, in practice.

Having studied some maps and documents this week, I seriously question if DU is still the best future plan. I don't believe it is. I can think of better plans that leave the cool new Spencer Dock as a terminus station without future disruption.

MyLove4Satan

https://www.boards.ie/discussion/comment/119422623#Comment_119422623

We all know this is never going to happen.

MyLove4Satan

https://www.boards.ie/discussion/comment/119424198#Comment_119424198

Cheers for the clarification. So Howth Junction becomes a major interchange. Even without the DU, there is a fair amount of connectivity on the DART with the new station. Even more so if the Metro gets built.

AngryLips

Wouldn't the Howth service on weekends be busier than the Malahide service what with all the tourists going to Howth head?

gjim

https://www.boards.ie/discussion/comment/119424243#Comment_119424243

The current "plans" have the the DART underground station located south of Mayor St while the DART+ West station is north of it - there's no vertical overlap between the two stations. The digging out would be happening on the site of the old North Wall station. Not that that means there is no disruption - connecting the two will involve escalators running under Mayor street and is likely to be disruptive. And just to be clear, "Spencer Dock" is only used as the name of the DART+ West station, the DART underground station is called "DU docklands" in the associated documentation.

I believe (but to be honest, cannot be sure) that the "temporary relocation" is due to the fact that launching the TBM and the associated portal works will sever rail access to the station during construction. But let's not resuscitate that argument again. Anyway, most of this arguing is a complete waste of time as I think DU is dead for decades, despite it being such an obvious and key piece of heavy rail infrastructure.

spacetweek

I actually hope that An Bord Pleanala come back to TII about the lack of future proofing DART+ West for DU and make them alter new SD station appropriately. Do it once, do it right.

"Anyway, most of this arguing is a complete waste of time as I think DU is dead for decades, despite it being such an obvious and key piece of heavy rail infrastructure."

I think they said they wouldn't consider it again until after 2042. But remember that DART+ (and Metrolink!) are probably going to be the mid-2030s before they're complete so 2042 isn't too long after that!

brianc89

https://www.boards.ie/discussion/comment/119425642#Comment_119425642

DU is definitely off the table for decades. I don't believe it'll happen in its current form.

Considering a Luas line could be built from James' Luas stop down Thomas St / Dame St to College Green, this would take enormous pressure off East / West city centre travel. The cost of such a Luas line would be insignificant compared to the cost of DU.

A better plan for a future DU would be Irishtown / Grand Canal Dock / Charlemont etc etc across the full length of the Grand Canal, all the way around to Heuston West, crossing the Dart (twice), Metro, Red and Green Luas lines.

It would actually cross the Red Luas line twice assuming the extension from the Point to Irishtown is constructed.

spacetweek

Do we know when we can expect an RO for DART+ South West? Next year?

cgcsb

https://www.boards.ie/discussion/comment/119425722#Comment_119425722

Aiming for December RO submission. But not optimistic right now. Seems pointless having a DART line with a few stations in isolated areas. Hard to justify the expense with no potential passengers. Acing ballyfermot and cabra stations was a big mistake.

DoctorPan

https://www.boards.ie/discussion/comment/119425554#Comment_119425554

Howths the branch line not Drogheda, the plans are for a frequent shuttle service up and down the branch.

https://www.boards.ie/discussion/comment/119424382#Comment_119424382

There isn't physically space on the Northern section between Fairview and Howth Junction to fit additional services unless you upgrade to ERTMS Lvl 3 and have moving blocks but the cost/benefit to that isn't in favour of its roll out.

There's about 1/1.5km between HJ & Bayside and between Bayside and Sutton. The only major distance is between Sutton and Howth itself but doesn't seem to be missing any major population that isn't covered by Sutton or Howth. Plus increasing stations increases journey times and puts pressure on the shuttle service to connect into mainline DART services at HJ.

Pete_Cavan

https://www.boards.ie/discussion/comment/119425719#Comment_119425719

How do you make the new SD station appropriate for DU? The level to the north is pretty fixed due to tracks from other lines in the area. The level to the south have a minimum depth due to having to pass under the Liffey. The tracks need to get from a fixed level to the north down to a new station level which is determined by clearance under the Liffey at a suitable gradient. Putting a ~200m long station at 0 gradient between those fixed points doesn't work.

Building a station with a platform level deep enough north of Mayor Street and the gradient down from the north would be too steep. Build the platform level at the point where the tracks would be at that point on its decent down towards the tunnel station and you are left with a flat section which needs to be sloping down.

You could build the tunnel station at the necessary depth south of Mayor Street but that is an enormous extra cost for no immediate benefit and how the fúck does a TBM bore into a live station and get extracted? Again you need a temporary alternative station plus have created a whole load for additional complex work.

The only thing that can be done now is stink the retaining walls for the new SD station deep enough that you can easily dig down deeper later, but that still requires an alternative station. We don't know that that won't be the case.

This what I think those moaning about the future tunnel fail to grasp - it is physically impossible to build the station now in a way that does not impinge on the future tunnel in some way.

brianc89

https://www.boards.ie/discussion/comment/119427226#Comment_119427226

You're spot on with this.

I don't believe Dart+ is compatible with DU. Developing DU in future would require significant impact on new Spencer Dock, one way or another. I just can't believe this would ever happen.

I think DU should be abandoned and a better route designed, such as along the entire length of the Grand Canal (from Heuston West to Irishtown) and connect to the Red Luas extension in Irishtown. Leave Spencer Dock as proposed in Dart+, which will be a fantastic asset for Dublin.

Sam Russell

Howth to Howth Junction is 9 mins. So allowing for turnaround means that it makes connecting with the ten minute schedule difficult. Howth Junction needs laying out differently if a simple transfer from the shuttle trains is to be easy, and not a long walk involving stairs and lifts.

Possibly a new station north of Kilbarrack Road allowing a simple transfer to south bound Malahide - Connolly trains might be worth looking at.

Pete_Cavan

https://www.boards.ie/discussion/comment/119427400#Comment_119427400

While developing DU in future would require significant impact on new Spencer Dock, I wouldn’t rule out the short term pain being accepted for the long term gain. I mean, if Docklands is available as an alternative and the closure of SD can be kept to 12 months or so, it could still happen.

But yeah, lets just move forward with DART+ as it is now (which is pretty bloody awesome, despite the way some react) and explore all expansion options at the necessary point in the future.

lucernarian

https://www.boards.ie/discussion/comment/119421646#Comment_119421646

As an interested reader, the attitude shown in the posts towards brianc89 have been quite poor IMO. They have supplied engineering documentation from original sources to show elements of "Spencer dock 2.0" will inevitably make the provision of Dart+ Tunnel/DU more difficult, and I've yet to see a reasonable explanation for how platforms and a tunnel can be built underneath the proposed station, without substantially or completely disrupting services to that station.

And I don't think we need to explain how myopic it would be to assume there would be the political and financial capital to build a Spencer dock 3.0 in 20-30 years.

brianc89

https://www.boards.ie/discussion/comment/119429125#Comment_119429125

Where were you two days ago to back me up?! Haha I joke.

It'll be interesting to see what DCC make of it. If you've seen in the Luas Finglas forum, DCC made some very good observations about extending the line in future to the Metro at Northwood or across the M50 to a new P+R facility. It surprised me to see...

Let's hope they look at Dart+ with a similar lens regarding DU. As I've made clear, I don't think DU is still feasible today. Let's remember it was designed 20 years ago. A lot has changed since then. I believe focus should switch to a DU / Metro along the length of the Grand Canal. But this is a separate argument. A decision can't be made on that until a review is done in light of the Dart+ plans

gjim

https://www.boards.ie/discussion/comment/119429125#Comment_119429125

I guess this it directed at me? Since I've been the one arguing with brianc89?

For the record, I'm the one who supplied the link to the Jacob's report for the NTA on the revised DU options - here.

The reason you have yet to see a reasonable explanation for how platforms can be built under the proposed DART+ West Spencer Dock, is because (as I've pointed out at least 4 times - referencing the NTA document) the planned DART underground station is NOT UNDERNEATH the proposed Spencer Dock station. It's on a separate site south of Spencer Dock - across Mayor St - on the block where the old North Wall Station building is.

Just to be absolutely clear - the railway or for then DART+W Spencer Dock station is marked blue below while the muted DART underground "docklands" from the Jacob's report is marked red in the diagram below:

I feel I'm starting to get irritated again and it's probably showing in my tone, as I thought some progress had been made in the discussion but the same misunderstandings keep getting repeated. Please look at both the Jacob's document and the RO documents posted by specialbyte (here) to see what is being proposed.

God knows we've been waiting decades for any sort of meaningful expansion of DART, reading the comment by spacetweek for example "hoping An Bord Pleanala reject the DART+W RO" just fills me with dread and despair for the prospects for any sort of advance for heavy rail PT in Dublin.

murphaph

ABP can't refuse planning based on these grounds. There is no planning application in for DU. As far as ABP is concerned it doesn't exist and isn't coming. Even if it would make complete and utter sense to build Spencer Dock station to be the future DU station, ABP cannot stipulate such a thing.

I think we can all probably move on because we've got our positions on this. For the record I would not like to see DART+ West delayed for any reason, even if I believe it makes sense to build Spencer Dock station to be the future DU station. The waste just bugs me.

Pete_Cavan

https://www.boards.ie/discussion/comment/119430345#Comment_119430345

This is what annoys me - the suggestion that there is some wonderful solution which avoids any future disruption - it simply doesn't exist. Like I point out already, if SD station is the future DU station, how do you later get a TBM out of there? No matter what way you do this, there are going to be future extra costs and disruption.

I think using the word "waste" in relation to SD station is nonsense. It will allow a big increase in trains terminating in the city centre for what could be a quarter of a century or more. And whenever it is replaced, it is entirely possible, maybe even likely, that some elements will be reused, or at least the excavations and retaining walls will make future works easier and less costly than they otherwise would be. The idea that it would result in waste is not accurate.

brianc89

I think it's fair to include a third piece to @gjim diagram. It's not just about the two platforms north and south of Major Street. It's the space required north of Sheriff Street to "get under" the Dart+ platforms.

I think it is 100% agreed that significant disruption, one way or another, would be required in future to build DU. My argument all along is - the sheer level of disruption would simply never be justified and isn't likely to ever happen.

But I think most of us are aware of our positions and ready to move on. No one falling out here!!

gjim

The other thing to note is that the DART+W Spencer Dock station, while critical for DART+, will NOT be critical if DU is ever built.

The need to terminate DART W or SW trains in the centre will go away.

DART West trains will use the curve at the North Strand to run through Connolly and onto the southern coastal line.

DART SW trains will go into the DU tunnel west of Heuston, under the south city and onto the northern line from the portal at Hawthorn Av. instead of through the Phoenix Park tunnel.

In fact, Spencer dock will be become somewhat orphaned in any post-DU world, I'm guessing. It's a pity that can't be used for Diesel trains - otherwise, it would actually make a pretty handy intercity terminus for Sligo and some Cork/Limerick trains for example.

brianc89

https://www.boards.ie/discussion/comment/119430692#Comment_119430692

It's a very good point actually. Spencer Dock would become significantly less important, as it would be become a transit station.

With regards to intercity services, I'm not sure how they fit into the wider Dart network given the capacity constraints, so I won't even go there. My sense is that launching intercity services from Spencer Dock would be a major advantage, so we wouldn't want to lose that.

However, I'm still adamant the disruption DU would lead to, would be extremely difficult to justify. There would be rolling disruption to all Dart lines and Intercity services for a few years (let's be realistic...). Also, established connections would be disrupted such as Red Luas connection at Spencer.

The idea of basically abandoning an existing tunnel in exchange for an astronomically expensive new tunnel would be difficult to justify, especially outside of Dublin.

brianc89

I think we should move the discussion around DU to the other DU forum at this stage? It's clogging up a broader discussion around the wider Dart+ proposal..

AngryLips

I think we can assume that when the time comes to realise the existing need for DU, it will be planned according to the conditions in place at the time, inclusive of the proposed and by then built Spencer Dock station that forms part of Dart+ West. What that plan will look like, nobody knows and it could involve a completely different alignment to what's there now or even a continuation of the northern portal elsewhere. For now, despite the need for DU, we know it's not happening. We've already seen such a change in vision and scope between Metro North and Metrolink as a result of changed conditions, for example.

Sam Russell

IR did not want to use the Phoenix Park Tunnel because it would make the DU project unlikely to get Gov support.

They were overruled over the tunnel and now DU is no longer on the planning horizon. A future DU could well follow the Grand Canal - or some other route. It could also be a metro.

murphaph

You would, when building the SD station simply create tunnel stubs and a false wall at the buffer stops. Then to insert the TBM you tear down the false wall and use the rail network itself to bring the TBM components in at night or during a couple of weekend closures and assemble it in one of the tunnel stubs and start mining. If one is really clever one could even make one platform with a removable lid to cover the spoil extraction conveyor belt and so on.