Dublin - MetroLink South West [feasibility study proposed]

I think it’s a good idea.
Dublin SW is absolutely gridlocked and does not have space for QBCs without CPOing large areas will which drag through the courts for decades.
Just continue the TBM to rathmines- rathfarnham- Firhouse- tallaght.
The green line luas can be updated to metro standard with from sandyford to charlemont with

1)a change at charlemont to continue to CC or 2)

just share the tunnel with DSW metros.

I prefer option 1 so that a huge changeover station can be built at charlemont just to spite the people who will raise the JR against metrolink!

Original DTO plans had a Tallaght - Harolds Cross - Beechwood metro in place to join to the Swords/Airport Metro

Since the locals kicked up a fuss and blocked the Green line going metro its actually easier to keep tunnelling south west from Charlemont avoiding the complex and expensive link to the Green line

That would be logical approach you simply keep on digging, leverage the existing supply chain and employee skill and experience. The real costs here are the setup costs to before you can actually start to dig so a continuous program is the cheaper way

But this is Ireland so no chance

So what your stating as fact is that it would be impossible to extract that soil from the TBM anywhere south of Charlemont allowing a full fit out and opening of Metrolink North of charlemont- is that correct?

So it’s not impossible then.

Could the TBM be taken out of the ground and transported to the other end of the DSW line and then tunnel to meet metrolink while it’s open?

Something like the eurotunnel? France tunneling towards the British TBM

Again whilst physically possible probably far from practical. I don’t think there anywhere big enough to dig a hole large enough to extract the TBM. Ultimately I think the TBM can only reall be buried, it either has to keep going and come out the far end or never come out again.
Short of CPOing Milltown golf course I don’t see anyway it could really be done.
Even at that the issue of thousands of trucks won’t go away

As a matter of interest, does anyone know how fast the TBM will tunnel in Dublin once it gets going? What I am wondering is how long would it take to get to Tallaght, and how long would it delay the opening of the planned metro.

There seem to be a lot of different speeds quoted on the internet, and with some of the faster ones, the delay would be months rather than years, and if the delay were only a few months, it might be worth it.

How much does a tunnel boring machine cost?

Is the cost of a second one actually significant relative to a 9 billion overall project cost (more if it goes South West?

One of the major differences between the metrolink (as originally proposed) and the earlier metronorth proposal was the decision to extend beyond the south city centre (St. Stephen's Green) and subsume much of the Green Line south of the canal into the metro project.

The underlying logic may have been that here was a possibility to add several kilometres of 'metro' on the cheap, even though metrification of the Green Line south of the canal would actually have minimal effect on speeds in that section.

It is fantastic that a whole new rapid transport corridor will be built between St. Stephen's Green and Swords when metrolink comes.

The proposed future southern section, which the bit to Charlemont is intended to facilitate has, I fear, not been well thought out. One of the things you can notice in developed European cities is that there's a tram, metro or rail stop/station around every two kilometres or less from where you are, no matter which direction you go. (In very developed cities, like Munich, you are almost never more that a kilometre from such a stop or station). In Dublin, going on a line between Dun Laoighare and Tallaght, via Dundrum, there's about a 7-8 km gap between DL (DART) and Dundrum (LUAS) with no such transport, and then about the same between Dundrum and Tallaght (LUAS).

The N11 is one corridor between DL and Dundrum which would be pretty easy to serve with a LUAS or metro, at some stage, but is not a priority for a number of reasons. On the other hand, the large gap between Dundrum and Tallaght is poorly served, in terms of rapid services into and out of the city.

I think the metrolink should aim, apart from opening up a welcome new corridor north of St. Stephen's Green, to open up a wholly new corridor on the southside. The current plan doesn't seem to envisage this, with the Charlemont terminus, which is quite patently designed to facilitate connection to the Green Line, and the Green Line only.

Any analysis of the population figures in southwest Dublin shows that areas like Rathmines, Rathgar, Terenure, Rathfarnham, Firhouse, Knocklyon, etc., have densities which seem to be higher, or much higher, than those along the current Green Line south of the canal, but public transport needs which are not remotely as well served. I am happy to provide those figures.

An improvement along such a corridor should be focused on prior to any unnecessary replacement of the Green Line south of the canal, which would bring no increase in speed and doubtfully necessary increases in capacity. The southside Green Line, prior to COVID, was busy, but basically because of Ireland's failure to build reasonably adjacent lines to 'compete' with it.

I think, because of the money involved, you'd have to do this in stages, just as the current plan is effectively to build between Swords and Sandyford in two stages, with the southern stage being basically a metro section built on the cheap with no practical advantage accruing.

One possibility which has often occurred to me is that you would build Swords-St. Stephen's Green-Rathmines, which (if done right) would be just a couple of hundred metres longer than the current plan. St. Mary's College has an astroturf front pitch, and a grass (it seems) back pitch, and other grounds in the area. With sensible rearrangement, it shouldn't be difficult to see that front pitch as a general working area for the next stage of development. (For example, utilising parts of those grounds and the adjacent Cathal Brugha Barracks as a way to remove spoil, perhaps even eastwards or westwards via the canal, as touched on above).

That base could get it out to, say, Rathfarnham, where something similar could surely be found.

There is no shortage of people on boards.ie with ideas as to where to build the next metrolink, and they even have their own thread.

I think Swords-Tallaght, built on the southside in stages, and based on the difference it would make in terms of reduced journey times for more people, should be the first metrolink.

Give or take a couple of hundred metres further to Rathmines, they don't have to sign off on anything more than they will have to if they approve the current plan to Charlemont.

Even if everything goes haywire, one plan offers the possibility of eventual quicker journeys through an area of the city where public transport is slow. (I've read on this board that it can be as much as 90 minutes to get from Firhouse to Town). The other plan, via Charlemont, seems to be focusing on miniscule improvements for much fewer people.

I live outside of Ireland but I visit Dublin every month or so, for family reasons, and I've been really impressed with the rollout of the Busconnects programme. With my leap card I see improvements every visit.

I started a thread called 'Metrolink - Alternative routes' back in 2018! 7 (seven) years ago. And nothing has happened, in terms of new rail inches, whether to Charlemont or to the southwest, in the interim.

How many trains per direction, per hour, could that tunnel take?

That's an interesting take, I agree with most of it although I'm still not convinced the densities are high enough to warrant the expenditure of a tunnelled Metro there.

Do you mind sharing those density figures if you have them to hand?

I wonder what the comparative densities will look like in future as well, when the likes of Cherrywood are fully built out on the Green line alignment.

I do agree that a new metro in the South West is a much larger comparative improvement than a metro upgraded Green line. I have heard it said that the Green line is close to capacity and there is only so much that can be increased by while it remains a Luas. That seems like the main argument for conversion.

the best thing that can happen is, things get far worse on the green line in terms of capacity, they will have to sort it then. Hopefully cherrywood and several other developments along the line, will force the issue… Its the only way that it will be addressed here. Give me a break if you think forward planning exists in this country…