Dublin Metrolink (just Metrolink posts here -see post #1 )

antoinolachtnai

Have you got a model for how you can have a 2 minute service on a line where trams have to cross the opposing path to reverse (as they would at St Stephens Green siding?

The line isn’t grade separated or anything near it anyway. Do you have a model for managing the road junctions so that trams can be kept evenly spaced as they go toward the city?

Where is your proof that trains can be run every three minutes from St Stephens Green to Parnell St? Sure it can be done on a sunny day.

Have you done a study to confirm that there will be little significant population growth on the corridor for the next 20 years?

citizen6

salmocab wrote: »

The roads around Milltown gc especially the one it’s on are a traffic nightmare lower churchtown road is one of the biggest bottlenecks in the city there is no way a massive amount of apartments could be built there without some massive roads changes. Also I’d suspect that the members are also the sort who would be able to tie these things up for a long time. Possibly getting some land for a portal is possible but can’t see anyway the whole gc is taken.

Good point. But we should be able to reduce the traffic associated with new developments by aiming them at particular groups. If you build mostly trade-down apartments aimed at empty nesters, you get a lot of retired people who don't commute in rush hour.

If you build student and shared living apartments, you get people who use public transport.

If you build staff accommodation for Vincents hospital and lay on a regular shuttle bus, you limit traffic there too.

And if you're CPOing a golf course, give first refusal on trade-down apartments to the members.

CatInABox

strassenwo!f wrote: »

Are you still peddling this line that the Green LUAS is near capacity?

Are you still peddling this line that the Green Luas frequency can be upped easily?

strassenwo!f

antoinolachtnai wrote: »

Have you got a model for how you can have a 2 minute service on a line where trams have to cross the opposing path to reverse (as they would at St Stephens Green siding?

This bit is really simple. A tram which is to terminate at the St. Stephen's Green siding comes in from Sandyford/Cherrywood and drops off its passengers at the St. Stephen's Green stop. It then goes around the corner and crosses the southbound track at the top of Dawson Street. It has almost TWO minutes to make this crossing. Not difficult.

When it terminates, any remaining passengers who failed to notice that this was the terminus get off the tram, the driver changes ends and gets ready to slot back in to the southbound schedule, without having to cross any lines at all.

antoinolachtnai wrote: »

The line isn’t grade separated or anything near it anyway. Do you have a model for managing the road junctions so that trams can be kept evenly spaced as they go toward the city?

I don't have such a model to hand, myself. But this kind of stuff is done in hundreds, if not indeed thousands, of cities around the world. I can't see why Dublin wouldn't be able to do the same.

At the moment, according to the LUAS website, they can manage spacings of as low as 2 minutes on the Green line. It'd only need to be 3 minutes (under the arrangement I'm suggesting) at major city junctions like O'Connell Bridge.

antoinolachtnai wrote: »

Where is your proof that trains can be run every three minutes from St Stephens Green to Parnell St? Sure it can be done on a sunny day.

I suppose the best proof is from the LUAS website, where they say they can manage tram frequencies of as low as 2 minutes. But there are many cities which manage to have trams every minute or 2 on (usually) central sections. Manchester, a nice rainy one, would be a nice example.

antoinolachtnai wrote: »

Have you done a study to confirm that there will be little significant population growth on the corridor for the next 20 years?

No, I haven't, but I think it is certain that there will be population growth on that corridor over the next 20 years.

Are there studies which show that the population in the catchment area of that line is going to grow by more than 50% over that time?

(Assuming that the numbers in the extra population mirror the need of the current population for use of the line at peak times, an increase in capacity of 50% using the measures I am suggesting should be able to deal with extra growth of up to 50% of the current catchment. Anything beyond that and we should start to look at an upgrade).

antoinolachtnai

The Luas website does not, as far as I know, state anywhere that it is possible to operate the Green line at a 2 minute frequency on a sustained basis, i.e., to deliver 30 trains in a single 60-minute period.

Can you name 30 cities where non-grade separated trams or trains regularly operate at a sustained 2-minute frequency?

Dublin will grow by around 30 percent in population over 25 years on average. It will grow considerably faster on the outer part of the Luas line. The Metro will also drive up demand by providing new destinations. It is hard to see the demand not growing by far more than 50 percent over 25 years.

Sure, you might be able to do the turnaround you describe in theory, but in practice it would be really difficult. It is just too tight a schedule. There is no slack. And the junctions further south on the line are going to knock it off too. The spacing would be all over the place.

tom1ie

salmocab wrote: »

The roads around Milltown gc especially the one it’s on are a traffic nightmare lower churchtown road is one of the biggest bottlenecks in the city there is no way a massive amount of apartments could be built there without some massive roads changes. Also I’d suspect that the members are also the sort who would be able to tie these things up for a long time. Possibly getting some land for a portal is possible but can’t see anyway the whole gc is taken.

No. The whole idea is we aim the development at not needing a car to get around. Use the metro, which will be frequent use busses and use cycling. We need to remove the idea about requiring a car to get around. This would be a great chance to do it.

Sam Russell

strassenwo!f wrote: »

I suppose the best proof is from the LUAS website, where they say they can manage tram frequencies of as low as 2 minutes. But there are many cities which manage to have trams every minute or 2 on (usually) central sections. Manchester, a nice rainy one, would be a nice example.

There are two at grade places where a two minute frequency would be impossible for local traffic. Remember, the trams go both ways and in particularly at St Raephaela's Rd at Stillorgan. There is a complex junction that does not work at the moment, let alone with increased frequency. Beechwood has a similar problem.

The other day I was on the Luas going from SSG to OCS and the tram stopped on occasions without reason. [The traffic lights were green but the tram light was stop and we had to wait till it changed - this was at the bottom of Grafton St and again at Westmoreland St - this was with little or no traffic.] If they cannot get this right, what hope is there with trams coming every minute at SSG. Remember, they are coming from both directions.

Remember the Metro is ten years away. A lot of growth is happening now.

antoinolachtnai

Sam Russell wrote: »

There are two at grade places where a two minute frequency would be impossible for local traffic. Remember, the trams go both ways and in particularly at St Raephaela's Rd at Stillorgan. There is a complex junction that does not work at the moment, let alone with increased frequency. Beechwood has a similar problem.

The other day I was on the Luas going from SSG to OCS and the tram stopped on occasions without reason. [The traffic lights were green but the tram light was stop and we had to wait till it changed - this was at the bottom of Grafton St and again at Westmoreland St - this was with little or no traffic.] If they cannot get this right, what hope is there with trams coming every minute at SSG. Remember, they are coming from both directions.

Remember the Metro is ten years away. A lot of growth is happening now.

It may well have been that the tram ahead had run into delays and the driver was trying to maintain the headway between trams.

There is no doubt that there are ways to increase capacity on the Luas. That is great, but it just won’t be enough for the long term.

LXFlyer

Sam Russell wrote: »

There are two at grade places where a two minute frequency would be impossible for local traffic. Remember, the trams go both ways and in particularly at St Raephaela's Rd at Stillorgan. There is a complex junction that does not work at the moment, let alone with increased frequency. Beechwood has a similar problem.

The other day I was on the Luas going from SSG to OCS and the tram stopped on occasions without reason. [The traffic lights were green but the tram light was stop and we had to wait till it changed - this was at the bottom of Grafton St and again at Westmoreland St - this was with little or no traffic.] If they cannot get this right, what hope is there with trams coming every minute at SSG. Remember, they are coming from both directions.

Remember the Metro is ten years away. A lot of growth is happening now.

Your continued expectation that trams on both lines will get a completely clear run through the heart of the city centre is not realistic.

There are a whole variety of legitimate reasons why it won’t happen - trams ahead blocking the route, headway maintenance (something Transdev performance is measured on), traffic and pedestrian light sequences - not allowing the latter would cause even more mayhem than is already the case.

Unfortunately we have a chosen a setup where the trams have to share space with everyone else - that means compromise is inevitable.

Then of course you get onto the yellow box blockers, traffic light jumpers etc. which will result in delays.

That being said, the maximum service provision through the city centre is every 3 mins and that’s only for a limited period in both peaks and even that is not simultaneously in both directions.

bk

Pretty much the accepted maximum frequency for non grade separated, on street running, trams all over the world is 3 minutes. In fact 3 minutes is an extreme case. Most do maximum 4 minutes with on-street running, so Luas is already pushing the boundaries of what is possible.

You can get down to 2 minutes with fully grade separated and a driver and down to 90 seconds driveless. But neither of those apply to Luas.

Beyond making all Luas trams 54m (which they are currently doing and gives it some temporary reprieve) I can't see how it will be possible to squeeze any more performance out of Luas. 10 years from now, it will be back to leaving behind people at platforms and needing upgrading to Metro.

antoinolachtnai

I read that the rule of thumb is that the minimum sustainable headway is double the longest traffic signal cycle on the at-grade portions of the line (https://books.google.ie/books?redir_esc=y&id=NbYqQSQcE2MC&q=rule+of+thumb#v=snippet&q=rule%20of%20thumb&f=false )

What is the longest traffic signal cycle on the cross-city route? I have it in my head that it is two minutes or longer, but I could be wrong.

strassenwo!f

antoinolachtnai wrote: »

The Luas website does not, as far as I know, state anywhere that it is possible to operate the Green line at a 2 minute frequency on a sustained basis, i.e., to deliver 30 trains in a single 60-minute period.

I'd be a bit surprised if it does.

When the LUAS was first rolled out, it was envisaged that the first lines would eventually be the first of many in the city. The 'Platform for Change' document from the Dublin Transportation Office - one of a long line of Department of Transport offshoots - had LUAS lines going everywhere. The idea of any one line requiring such a frequency, given the coverage of the city which they were proposing, would have been absurd.

antoinolachtnai wrote: »

Can you name 30 cities where non-grade separated trams or trains regularly operate at a sustained 2-minute frequency?

30 cities?

Not 10, or 20, or 40?

This sounds like you are using the David Drumm method of number selection.

I'll give you three (3) off the top of my head where I've seen overground tram lines in operation: Manchester, Krakow (Poland) and Dresden (Germany). Those three cities have central areas where there is a tram going through every 1-2 minutes.

In all those cases, those are trams which are coming from different areas, and using the central route to go to other areas.

In the three cities mentioned above, the tram lines using the central areas are effectively competing with one another. Their termini are often just 2-3km from each other, yet they share a central section, creating a situation where the residents have good options.

For rapid suburb-to-city transport, outside of the DART line, Dublin has unfortunately only the Green LUAS and the Red LUAS. There is no competition between these lines because they're so far apart. The obvious thing is to create a LUAS line, or LUAS lines, between those two.

In Dublin it has been determined that there is no corridor available for a LUAS in the south-west area, and those areas which would seem to be ripe for development of a metro can't unfortunately be talked about here. (because of the moderator situation)

So, instead of developing the corridor between the LUAS lines into a metro, we decide to plough yet more investment into a corridor which does not need to be upgraded.

I am certainly stumped when asked to come up with a city which has a 2-minute frequency along just one overground corridor, but I guess it's because other cities have developed more routes which share central areas in which there is a two-minute frequency and competition between those routes. Dublin hasn't done that.

antoinolachtnai wrote: »

Dublin will grow by around 30 percent in population over 25 years on average. It will grow considerably faster on the outer part of the Luas line. The Metro will also drive up demand by providing new destinations. It is hard to see the demand not growing by far more than 50 percent over 25 years.

What new destinations is the currently proposed metro providing on the Southside? I haven't seen any in this metrosouth plan.

And do you reckon that these new homebuyers, with their starterhome income, are going to be focused on homes in the expensive southeast?

antoinolachtnai wrote: »

Sure, you might be able to do the turnaround you describe in theory, but in practice it would be really difficult. It is just too tight a schedule. There is no slack. And the junctions further south on the line are going to knock it off too. The spacing would be all over the place.

Antoin

I don't think anybody thinks you're going to maintain an exact three minute schedule here. An average 3-minute schedule would surely suffice, as it seems to do in other cities.

LeinsterDub

Reading on Twitter that the NTA have confirmed to DCC that ML will be a single bore solution. This will help with the Na Fianna situation too apparently.

https://twitter.com/PaulMcauliffe/status/1009097011621187584

antoinolachtnai

Average? Average doesn’t cut it i’m afraid. You will have massive backups on the platforms and then bunching of trains if you can’t keep the trains regular. Operating a train system at this level is not like running a few buses.

Manchester as you rightly say has many converging lines which share a central section which is quite well segregated. It’s very different. (I mentioned 30 because our co-poster said there were hundreds or even thousands of cities operating tram lines or train lines at these frequencies.)

Dats me

Would help with Na Fianna due to tunnel portal at Northwood & elevated over M50

CatInABox

Dats me wrote: »

Would help with Na Fianna due to tunnel portal at Northwood & elevated over M50

Apparently there's a housing estate where they were planning on putting the station at Northwood, presume that there'd probably be an issue with a tunnel portal around there too.

They were also looking at continuing under the M50 and surfacing at Dardistown, specifically the Na Fianna pitches there, which may be a better option than going from 30 metres underground to over the M50 and back down again.

Anyway, moving the tunnel portal away from Na Fianna makes sense, I'll admit that it took me a while to see sense on it, but once you take a step back, a tunnel portal there really didn't make sense. Great that one major objection to this project is already dealt with essentially.

strassenwo!f

LeinsterDub wrote: »

Reading on Twitter that the NTA have confirmed to DCC that ML will be a single bore solution. This will help with the Na Fianna situation too apparently.

https://twitter.com/PaulMcauliffe/status/1009097011621187584

Wonderful.

After looking at 38 possible solutions on the northside of the city, which they have whittled down to just ten.

It will be interesting to see what routes were looked at on the southside of the city.













wonderful

jd

CatInABox wrote: »

Apparently there's a housing estate where they were planning on putting the station at Northwood, presume that there'd probably be an issue with a tunnel portal around there too.

The station would have to be overground, to the north of the portal.

Having the portal north of the M50 gives them a range of possible station locations for Northwood (but they'd better move quickly, before more developments start there!)

jd

strassenwo!f wrote: »

Wonderful.

After looking at 38 possible solutions on the northside of the city, which they have whittled down to just ten.

Where are you sourcing that there are ten remaining solutions? What are they?

CatInABox

strassenwo!f wrote: »

Wonderful.

After looking at 38 possible solutions on the northside of the city, which they have whittled down to just ten.

It will be interesting to see what routes were looked at on the southside of the city.

wonderful

Not sure what you're getting at. The Metrolink process for the northside (Swords to City Centre) consisted of a process that examined 34 feasible routes, with ten examined in detail, of which one was chosen as the emerging preferred route. Following the public consultation, they'll published the preferred route in time.

As to the routes examined on the southside, I'd hazard a guess at one, and only one, the Green line Luas route. This project was always going to tie with the Luas, so the two studies that they conducted were to examine the Luas tie in, and the work required to upgrade the Green Line. No other routes needed looking at.

CatInABox

jd wrote: »

Where are you sourcing that there are ten remaining solutions? What are they?

He's behind the times. The EPR is the output of those ten solutions.

marno21

Surely running it elevated over the M50 just creates needless gradients either side of the M50 and adds expense due to needing 2 tunnels? One continuous tunnel from Dublin Airport - Charlemont makes sense.

Anyone have opinions on tonight's development? No more tunnel portal at Na Fianna and single bore construction.

Kermit.de.frog

The biggest infrastructure project in the history of the state is to be disfigured because of a GAA pitch which tells you all you need to know about Ireland really, doesn't it?

If anyone can name a single country in the rest of Europe that would tolerate this sort of nonsense i'm happy to hear of it.

marno21

Kermit.de.frog wrote: »

The biggest infrastructure project in the history of the state is to be disfigured because of a GAA pitch which tells you all you need to know about Ireland really, doesn't it?

If anyone can name a single country in the rest of Europe that would tolerate this sort of nonsense i'm happy to hear of it.

There aren't any. This is an Irish solution to an Irish problem.

Look at the Heathrow 3rd runway proposal and the effect that has on the local area. The Na Fianna issue is miniscule in comparison.

marno21

The Irish Times have an article on the wonderful news that the GAA pitch of a club with 3,000 members will not be disturbed to make way for a high capacity public transport system capable of transporting upto 54,000 people per hour.

https://www.irishtimes.com/news/ireland/irish-news/metro-link-set-for-changes-aimed-at-reducing-disruption-1.3536700

Some reaction from local representatives:

Fine Gael Dublin North West TD Noel Rock said the “idea of Na Fianna’s main pitch becoming a tunnelling site for seven years was simply not a runner”.

“I would like to commend all involved for bringing about a significant alteration in this plan, which will now see the main pitch retained, the construction footprint reduced, and the timeframe of disruption reduced from seven years to two,” he added.

Paul McAuliffe, a Fianna Fáil councillor in the area, said: “Should this be the final decision, the massive effort of clubs and residents in fighting a proposal that would damage the economy should be acknowledged.”

Not sure what you mean here Paul, I don't see how the TBM site at Na Fianna "would damage the economy."

Kermit.de.frog

Gombeen politics.

I have been thinking of packing my bags for some time for a better quality of life. I don't see anything changing in this country.

CatInABox

I find it hard to be too annoyed over this. It's the public consultation phase of the project, they have to be open to changing their plans based upon what they hear. I know that almost everyone here wants better infrastructure in Ireland, but running roughshod over local complaints isn't the way to do it.

I'd be more annoyed of the Metrolink went all the way through planning and was rejected because of this Na Fianna issue. As it is, it's no longer a problem, so let's get on with it.

Also, ignore the politicians gloating about this, in ten years time they'll be jumping on the bandwagon saying how much effort they put in to bring it to this area, etc.

prunudo

Just on the latest news about single bore. Would 2 smaller bore tunnels not be easier and cheaper to build than one larger tunnel. I would have thought a larger tunnel needs larger tbm, stronger structure etc.
Maybe over simplistic calculations but there could be 2.5 times the amount of material coming out too.

LeinsterDub

https://twitter.com/PaulMcauliffe/status/1009327490064666624

Outrage as public consulted during public consultation and plans revised to avoid a massive headache on the back of said consultation

CatInABox

jvan wrote: »

Just on the latest news about single bore. Would 2 smaller bore tunnels not be easier and cheaper to build than one larger tunnel. I would have thought a larger tunnel needs larger tbm, stronger structure etc.
Maybe over simplistic calculations but there could be 2.5 times the amount of material coming out too.

Twin bore would have been cheaper without a doubt, that's why it was favoured in the first place. There'd also be less compensation/remedial works required, as a larger bore results in a larger "settling" area.