Dublin Metrolink - future routes for next Metrolink

I was in Dublin last week for a few days and, needing to put in some proper exercise to help with the weight, I decided to walk along a section of what a south-westerly extension of the current metrolink might travel from St. Stephen's Green.

It has always been my contention that the metrolink between Swords and the city should be extended towards the southwest of the city (some would say the south-central part of the city), eventually reaching places like Firhouse and Knocklyon, primarily because (i) the suburbs along the way generally have higher densities than those along the southside Green LUAS line, (ii) the reduction in journey times along such a corridor would lead to massively reduced journey times, and (iii) no overground LUAS line seems to be readily available in that area.

There is also no one route on the southside which can act as a counterbalance to the scale of potential passengers provided by Swords, the Airport and Ballymun, and to a lesser extent other northside locations, and I have suggested that Dublin should eventually aim for two southside routes to balance this out: one to/from a Rathmines/Terenure/Rathfarnham/etc corridor and one to/from a Harold's Cross/Kimmage/Walkinstown corridor (this second one mostly does not have anything like the population density of the first, but it has a big prize in terms of public transport integration at Walkinstown Cross).

Camden Street, just north of the Bleeding Horse pub, where the road is four lanes wide, would seem to present an ideal opportunity for construction of a 3-track metro station, under the road, between St. Stephen's Green and the canal. There really is lots of space there, and the three tracks could initially be used to incorporate a turnback - given the volumes coming from the northside - until a line towards Walkinstown is developed.

Assuming that the initial stages of the 'Rathfarnham' line are developed first, there seems to be no reason why construction of a line from St. Stephen's Green to Rathmines should cost significantly more than a line between St. Stephen's Green and Charlemont (the current plan).

The rugby pitch, now apparently an astroturf one, in front of St. Mary's College was in the final stages of being relaid when I walked past. It would obviously be a pity to destroy somebody's new work, but it would be an ideal place to put an initial Rathmines terminus - not costing noticeably more than the current plan to Charlemont. There might need to be be a small amount of CPO of adjacent buildings, but there seems to be scope there either for building a station under the rugby pitch or, an option I would prefer, for building a station under the road and using the pitch as a temporary route for road traffic along Rathmines Road. (There seems to be potential here for removal of spoil - the school has a second pitch there and is adjacent to the Cathal Brugha Barracks, and it surely wouldn't be impossible to figure out some way to get the spoil out by some route involving that, if necessary. The IRFU should be able to step in to find some help with the temporary loss of a pitch).

Further on on my walk, the petrol station at the bottom of Rathgar Road would seem to be an ideal location for a second station in the Rathmines area. It is, of course, only around 700 metres from the first one mentioned above, but that is a very dense area and it has many buses from other parts. This would not be an unreasonable separation of stations in most cities with a developed metro.

Beyond that, at the top of Rathgar Road, there's the major junction at the church. This is around 1 km away from Rathmines, so it should obviously be a location for another underground station. Major traffic management required there, but the local population density is decent.

It obviously gets tougher at Terenure, where there is a major turn required to get towards Rathfarnham, Firhouse and Knocklyon. However, the vehicles envisaged for this metro do have considerable flexibility and an underground station south of Terenure Cross, on Rathfarnham Road, might be an option. This would also be around 1 km from a stop in or around Rathgar Church.

In the overall scenario which I outlined above for the southside metro lines emerging as a counterbalance to the Swords metro on the northside, this would eventually give a metro line at one end of the Terenure Road West/East catchment on the Rathfarnham/Firhouse/Knocklyon line. With a potential Harold's Cross - Kimmage - KCR-Walkinstown metro line at the other end of Terenure you'd have very effective coverage of an area with very good population density.

I've often felt that the way to get across the Dodder on the way to Rathfarnham would be to have a standout bridge over the river, perhaps even with a station on it. Apart from being a great advertisement for the metro this would surely be cheaper than going underground across the Dodder, and with the number of roads leading into the bridge it could be the most effective solution for potential passengers.

I unfortunately didn't have time on my recent Dublin visit to walk further towards Rathfarnham and see how it might eventually pan out. That's for the next time and, in any case Terenure and Rathfarnham are some years away under the current budget.

Because of pressure of time I had to turn back at Dodder Bridge south of Terenure and walk back along the Dodder, past what I've always called the 'Arc de Triomphe' near Orwell Road and eventually make my way to the Nine Arches and the Milltown stop.

There'd be a very nice separation of lines into/out of the city if there was a metro line over(or under) the river at Rathfarnham and a line over the Nine Arches. It would be very appropriate for the densities involved.

Last Stop wrote: »

Now let’s talk population density. How on earth did you come to the conclusion that this route has a higher population than the green line. Did you come across a single building over 5 stories along the route? Did you come across over 100 apartments total? That before you even consider the impact Cherrywood is going to have on the green line (it will sit in the top 30 Irish towns by population!!)

I'm basically just working on the official figures, from the last election.

Terenure has 4,391 people per sq.km of population, and Dundrum has 3,349 people per sq. km of population.

Rathfarnham has 4,139 people per sq.km. of population.
Firhouse has 3,753 people per sq.km. of population.

These are the official figures which I can currently find. Terenure's population density is obviously much higher than Dundrum's, and heading further out of Dublin you can see that Rathfarnham and Firhouse are also much higher than Sandyford, Glencullen or elsewhere.

You are writing nonsense.

Last Stop wrote: »

As I suspected, you’re using EDs which do not accurately reflect the traditional place names we typically use. An example being Rathfarnham attached. As you can see, the east side of the ED is within walking distance of the green line. A Rathfarnham metro station would be miles away from a number of the Ballinteer EDs which border the Luas Line.

Good work! I never knew that part of 'Rathfarnham' was actually north of the river Dodder. I'd always worked on the basis that crossing the river south of Terenure brought me to Rathfarnham.

I don't think it changes anything, however. Much of that electoral district would still be within walking distance of a Terenure station on a putative southwest metro line (despite being in 'Rathfarnham'). If I lived right in the middle of that area I'd have a choice: do I go to the LUAS (journey time into St. Stephen's Green ca. 14 minutes) or do I go to the Terenure metro station (journey time to St. Stephen's Green ca. 10 perhaps, if there are stations at Rathgar, 2xRathmines, Camden Street). Not much in it, but I'd probably go for Terenure.

That one area illustrates very nicely how money spent on a southwest metro could help to reduce pressure on the Green LUAS.

Farther out, in real Rathfarnham, and Firhouse and Knocklyon, where the LUAS is not an option, the benefit would be in massively reduced journey times into town. Probably to 20-25 minutes to St. Stephen's Green, compared to the 60-90 minutes which it apparently is currently, and each incremental step along the way should provide journey time reductions towards that.

I'm still not seeing any areas of Ballinteer which border the Green LUAS.

I'm going to have to leave your stuff about "calcs" as I don't know what you are talking about.

Last Stop wrote: »

Rathmines is far from high density

Rathmines is very high density, in a Dublin context. I can't think, off the top of my head, of a suburb in Dublin which has a higher density.

Last Stop wrote: »

When you compare the population density of areas on both sides of the green line, they are significantly higher than the ones you have quoted and growing!!

You may be right, perhaps with up-to-date local knowledge, that it is growing on both sides of the line. I only have the 2016 census figures to work with.

Last Stop wrote: »

Please explain how it is a replacement and not an upgrade?
Are they replacing the tracks - no
Are they removing stations - no

It will be considerably quicker between Charlemont and O’Connell!!

Which journeys will take longer?[/QUOTE]

No, they're not replacing the tracks. And, no, they're not removing any stations. They are sensibly carrying on, as is.

Last Stop wrote: »

Think that might be better rephrased as you don’t know what you’re talking about based on your station box calculations (shortened to calcs)

I've told you, up above, that I'm waiting for a definitive answer about the size of a 4-track station size in a city with a well-developed public transport system. We can then work out, perhaps by extrapolation:D, what the dimensions of a of a 3-track station might be.

Last Stop wrote: »

Ballymun, Beaumont, Cabra all have higher densities
In any event the most dense part of the Rathmines ED is around Ranelagh who would benefit fit far more from the green line upgrade

Ballymun, Beaumont and Cabra may indeed have higher densities (I haven't yet looked). But they're not being discussed as locations for alternative routes. Ballymun is on the route of the proposed metro, but I've yet to see any proposed alternative metro route through Beaumont or Cabra.

You say that the densest part of the Rathmines electoral district is Ranelagh. Can you show that to us?

Last Stop wrote: »

That’s even using 2016 stats

Yes, unfortunately all I have to hand is the census data for 2016

Last Stop wrote: »

If you could answer the question asked in future rather than trying to be smart to avoid admitting misinformation that would be great

I wasn't trying to be smart. The NTA themselves said they are not going to replace the Green LUAS line on the southside for around two decades, or more, because it isn't necessary.

I think that Dublin should use those two decades to deliver quality, and rapid, public transport to other southside areas.

Last Stop wrote: »

Any update on this?

Indeed there is. I just got the figures from my friend with the laser late this afternoon.

My local station has two island platforms, one for mainline services and one for commuter trains. (There are no underground trains in my city).

One platform (the intercity platform) has a width of 9.70 metres and the other (the commuter platform) has a width of 9.10 metres, each with a set of steps leading to/from the platform near the end (but not actually at the end - there are lifts at each end, on both platforms, and enough room either side of the stairs for access to/from those lifts).

The two tracks between the platforms have a total width of 8.28 metres, which accomodates both commuter and intercity trains, and occasional freight trains. In other words, the operational requirement for safe throughput of trains, in my town, is 4.14 metres on each track.

Obviously, the space required by trains on the outside tracks should be the same, perhaps lower as they don't ever have any obstacles like oncoming trains in their path, but certainly not higher.

Thus we can safely say that the total operational width required by my local station is 35.36 metres (thirty-five point three-six metres).

If we now transfer those figures from an overground station in continental Europe to a possible 3-track underground station in or around Camden Street in Dublin with an island platform and a side platform, and assign a width of 10 metres per island platform, 5 metres for the side platform, 4 metres per track, and let's say a total of 1 metre either side for the cabling and the concrete box, you come up with a side-to-side operational footprint of 29 metres.

You might be able to reduce the platform size a bit by having those glass doors that some metro systems have - I'm not sure if they are planned for Dublin's metro - and the figures above may also be a little skewed by the fact that my local commuter train is operating in an environment which also includes freight trains and intercity trains - as mentioned above - though they are not on the same tracks. Dublin's metro would not be.

Even so, I can't see how the overall operational footprint of a potential 3-track Camden Street station could be got down to below about 27 metres (twenty-seven metres).

I think to build a junction station serving Rathmines, etc., on one branch of the proposed metro and Harold's Cross and Walkinstown on another, as I have suggested, you would probably have to compulsorily purchase (and demolish) the one-level Zaytoon, Boylesports and other buildings on that stretch of Camden Street near the Bleeding Horse. If that were done, such a station at Camden Street should be eminently feasible. Other solutions are doubtless possible.

(Of course, it may be that building a station under what are one-storey buildings, effectively a stretch of bungalows near to the city centre, while leaving them intact, is actually an option).

I am a little hampered because I'm not aware of any website which allows preliminary assessment of the urban space in Ireland, street widths, etc. Other countries that I work in seem to have variously more or less developed versions of something like this.

I am also curious about this post:

Last Stop wrote:

Camden St.
4 lanes = 14m... a 3 track station would be 30m x 200m long minimum!
Where’s the station entrance? The footpaths there aren’t wide enough

Why 200 metres?

If you can build the operational 'station', with the tracks and the platforms, you can then build the mezzanine level with shops and ticket machines and pastry sellers and so on, and the whole thing becomes progressively bigger or smaller as needs be at street level.

I still struggle to see how a metro station for a 90 metre tram could morph into a station with a length of 200 metres.

(There is of course a precedent, in that the exalted people at An Bord Pleanala even approved, under the earlier metronorth plans, a station at O'Connell Bridge which was around 400 metres long for a tram which was just 90-metres).

I'm curious why you think that a length of 200 metres should be necessary for a metro station in a location like Camden Street.