[article] RPA defends capacity of proposed metro trams

[undo]

This article from the Irish Times was posted at here (http://buckplanning.blogspot.com/2008/02/rpa-defends-capacity-of-proposed-metro.html) a couple of days ago:

Specifications for Dublin's Metro North to be released later this month are to concentrate on 90-metre trams as opposed to the higher capacity heavy rail carriages, the Railway Procurement Agency has confirmed. Tim O'Brien reports.

The confirmation comes amid mounting concern over capacity problems on the existing Luas lines as well as fears that Metro North could suffer similar peak-hour capacity problems within a decade of opening.

The Irish Times has learned the RPA was advised by some of the bidders for the Metro North contract that even if it opts for the narrower 2.4 metre tram system, it should build the tunnel wide enough to later convert to 2.8 metre carriages.

The RPA has also been told that comparable capital cities to Dublin, including Prague, Hamburg, Vienna, Berlin, Lisbon, Munich and Madrid all utilise the higher capacity, wider-bodied carriages in their undergrounds.

Munich, which was the subject of a Department of Transport visit in 2005, uses a "low capacity metro" at 2.8 metres wide, and is capable of carrying in excess of 30,000 people per hour in each direction , some 50 per cent more than the 20,000 capacity of the proposed Dublin underground. Dublin's Dart which can be up to 170 metres long has capacity for 36,000 people per hour per direction. The capacity issue comes as RPA planners face criticism over passengers being left on the platform during the morning rush because trams are full. A Dublin City Business Association spokesman, Tom Coffey, said "to be credible the underground has to have a capacity of about 35,000 people per hour in each direction.

"We can't have a metro which is going to reach capacity six years after it opens. There is no going back to widen a tunnel after it is built and this infrastructure should be designed to last 100 years, as it did in London and elsewhere," he maintained.

The issue also comes as a two-day conference on infrastructure heard details of a Dublin Institute of Technology Futures Academy report which predicted population on the island would rise to seven million people by 2020, with about 1.5 million extra people moving into the Dublin Belfast corridor.

A number of commentators including the head of the National Roads Authority Fred Barry said the population increase - similar in size to the existing population of Dublin - would require another large-scale increase in public transport. Mr Barry said the increase would result in demand for much more rail transport as part of "a successor to Transport 21, a Transport 22, if you like".

However, speaking at the conference the chief executive of the RPA, Frank Allen, said he was "absolutely confident" that the capacity of 20,000 people per hour in each direction was sufficient for Metro North.

He remarked that just "isolated parts" of the London and Paris metros were operating above that capacity and it would be very hard to find other examples in cities in Europe. He said he was "very, very confident" of the capacity of the 90-metre carriages operating at a two minute frequency during peak times.

Mr Allen said the population forecast in the Fingal County Development plan was more pertinent than the all-island forecast. Metro North was, he said, "fully integrated with population projections" and "Fingal is absolutely confident that the capacity is more than is required".

The Irish Times

The Independent also isn't too sure about metro light's capacity (link (http://www.independent.ie/national-news/metro-too-small-to-cope-with-demand-says-expert-1282539.html)):

Metro 'too small' to cope with demand, says expert

Wednesday February 06 2008

A boss of world metro maker Siemens says the planned Metro from Dublin city centre to the capital's airport will be far too small to cope with projected demand.

Dr Werner Kruckow, chief executive of Siemens Ireland, said yesterday that the proposed Dublin Metro will only be able to handle 20,000 passengers an hour in each direction which is far "too small".

The transport chief said the development of a sustainable city like Dublin requires the fast implementation of a high capacity transportation network, similar to that in other European cities.

Munich in Germany had a metro with a capacity for 36,000 passengers per hour in each direction, yet the maximum it has ever carried was 30,000.

"Dublin is planning for a peak of 20,000 per hour in each direction. This is much too low," the Siemens chief said in Dublin yesterday.

The Metro plan also failed to take account of projected population increases, which is due to reach two million.

[Mark]

The issue here is not length of trams and stations or frequency but rather the actual width of the units which in order to keep costs down and to provide interoperability with the Luas is set at 2.4m. Most metro units are 2.65 or 3m wide.

Something will have to give.

[Mark Gleeson]

Figures which I've seen suggest a 22.5-25k capacity

Originally it was 18k

Question: Will it be busier inbound or outbound in the Morning Rush?

[Brian Condron]

What is the actually story regarding tunnel widths, forgetting about the station platforms at the moment, can the tunnels cater for wider trams?

Surely in this day and age it is possible to have platform edges which automatically extend to meet the tram? In New York when the two subway systems were combined, automatic ramps were installed so that trains from the narrower system could use stations from the wider system. Some stations still have them.

[undo]

Surely in this day and age it is possible to have platform edges which automatically extend to meet the tram?

But that would require the RPA admitting that underground Luas won't cut it. And that they are currently not prepared to do.

[Mark]

What is the actually story regarding tunnel widths, forgetting about the station platforms at the moment, can the tunnels cater for wider trams?

Surely in this day and age it is possible to have platform edges which automatically extend to meet the tram? In New York when the two subway systems were combined, automatic ramps were installed so that trains from the narrower system could use stations from the wider system. Some stations still have them.

Given the height of the trams plus OH is 3.8 m plus and the tunnels are singel bore then the width of the trams wont be an issue. Its platforms and at grade and elevated structures which are the issue.

[undo]

It's interesting you should mention the overhead wire. That reminds me how proper metro systems normally use third rail, not overhead - for the very reason that it allows smaller diameter tunnels to be bored, reducing costs. Of course, with a third rail, at-grade intersections are impossible. I wonder if the RPA ever weighed the higher cost of proper segregation against the reduced costs of tunelling at a lower diameter. It might just turn out that a real metro is even cheaper to build.

[Brian Condron]

I can just imagine it if they had opted for third rail, another railway system being built in Dublin that is not compatible with those existing. Papers would have had a field day.

[Prof_Vanderjuice]

I remember reading somewhere (I half-recall it was a discussion of the Tyne and Wear Metro in an engineering journal, but I could be mistaken) that there was no tunnel-diameter advantage for third rail if you had to provide an emergency walkway anyway.

[Colm Moore]

Question: Will it be busier inbound or outbound in the Morning Rush?Given that the city centre and the Nass Road areas are the two prime destinations, why would it be busier outbound?

What is the actually story regarding tunnel widths, forgetting about the station platforms at the moment, can the tunnels cater for wider trams?I imagine the difference in cost beteen the two tunnel sizes is relatively modest in terms of overall cost. If larger vehicles are used later, the smaller vehicles can be cascaded onto other lines

Surely in this day and age it is possible to have platform edges which automatically extend to meet the tram? In New York when the two subway systems were combined, automatic ramps were installed so that trains from the narrower system could use stations from the wider system. Some stations still have them.I imagine it is better to operate with a single fleet. Designing the platform edges such that they can be changed over say a weekend closure in a "Big Bang" changeover would be desireable, although the familiarisation training of drivers on the new vehicles for the characteristics of that section of track might be an issue. Basic training of the drivers on the vehicles could be done somehwere else.

It's interesting you should mention the overhead wire. That reminds me how proper metro systems normally use third rail, not overhead - for the very reason that it allows smaller diameter tunnels to be bored, reducing costs. Aren't new third rail systems banned on safety grounds?

[undo]

Aren't new third rail systems banned on safety grounds?

By whom? The Irish government? Or on an EU level?

[Mark Gleeson]

Conductor rail systems are not recommended by the RSC

[James Shields]

Heavy or light rail makes no difference as long as it runs on time and carries enough people. For anyone who thinks light rail can't do Metro, book a cheap flight over to London and have a look at the Docklands Light Railway. While it's quite different to the system proposed for Dublin, it does show that a light rail system running at high frequency can provide a lot of capacity.

[ofjames]

Right, is there anyone out there who can give an accurate (say with a 2500 people pd/ph margin for error either side) what the demand for this service should be

i) when it opens in 2013 (hopefully)? will 20,000 people pd/ph use this line the first week it opens? if not? how many will?

also, in the longer term. is there authoritative evidence as to what the demand would be

ii) circa 2025?
iii) circa 2050?

In my opinion, International comparisons are pretty useless when it comes to this. The build capacity ought to be dictated by one thing and one thing alone, the current and future demand on this route!!.... If only someone could accuratley pinpoint this!

[Mark Gleeson]

Firstly the capacity is closer to 22,500, a good 3 times beyond the Green line Luas

Demand is split three ways
City, DCU, Airport

So in fact the system will carry well more than 20k an hour since it will be heavily used in both directions

Rough guess is year one peak flow would be 12k, they are only quoting 30 million passengers at start

RPA are working on 2 minute intervals, they could go to 90 seconds and then be hitting 30k per direction capacity

Remember when this started 4k was year one capacity with a limit of 18k on capacity, now at 22.5k with potential to get 30k easily

[undo]

Remember when this started 4k was year one capacity with a limit of 18k on capacity, now at 22.5k with potential to get 30k easily

If the initial plans were so far off the real demand, how can we be sure the current estimates are anywhere near accurate? Wouldn't it be better to build the system so it can be expanded to >> 30k peak if the demand arises say 50 years from now?

[luasifer]

Is the Paris metro not a real subway or metro system? Does it use third rail? Not that I'm aware of anyway!!

[undo]

Absolutely, Paris is a proper heavy rail metro using third rail for its power on all its lines, whether using steel wheels or rubber tires, human drivers or driverless.

[MrX]

I'm not sure how Madrid is suddenly comparable to Dublin as a city?!
The Madrid metropolitan area contains 4 858 000 people and Berlin's got >3.7 million!

Munich, Frankfurt, Leeds, Lyon, Porto, Copenhagen, Stockholm, Saville, Glasgow and Marseilles are more comparable to Dublin

http://en.wikipedia.org/wiki/Largest_urban_areas_of_the_European_Union


On the capacity issue, installing something grossly below capacity would be completely nuts, but at least it would be in line with normal Irish planning policy which has been used for everything else .. M50... ?

Also, whether it's 3rd rail or overhead wires really makes no difference. Plenty of other modern metros use overhead power, including many of the major Spanish cities' systems. There's basically a bus bar at the top of the tunnel, it doesn't take up very much space. When the train's in the tunnel, the pantograph (contactor on top) is folded almost completely down and just scrapes along the ceiling. When it's above ground, the system's more like the DART or Luas. It's safer, and really not a huge issue to implement. 3rd rail's generally only implemented in extensions to old systems and has a lot of safety and maintanance disadvantages. They don't comply with modern (post 1950s) electrical safety legislation but are "grandfathered" in countries that had significant 3rd rail infrastructure since the turn of the 20th century as it was simply too complicated and too costly to replace.

I don't really see 3rd rail or overhead power being much of an issue, the issue is the capacity of the trains and the future-proofing of the tunnel(s)

[Aphfaneire]

Looking at these numbers and the claims that it has a capacity 3 times that of the current luas green line, i can easily see that this sevice fulfills "current" needs.

However current needs are meaningless! The true goal of a proper future transport system would be to cater for all commuter corridors with large capacity high frequency services. Not only that but it will have to be GREEN! ITs an electric system, it has to get power from somewhere, where is it going to come from, the national grid? With population growth and a proposed electrification of several Dublin lines, there will be a huge demand on power, wheres it going to come from:confused:

The Metro should be built to this plan, as it seems efficiant for the time being, but to respect are children and grand children the tunnels should be wide and the platforms adjustable so that with minor work to a segregatted line we can make the metro a real underground service.:rolleyes:


Also, if we all want to stop global warming etc etc, trains, trams and buses and anything else should be the governments only priority. Its not like hydrogen fuel cells or sollar cars are viable in the very near future.:rolleyes:

[Colm Moore]

Low-capacity design favoured for Metro North
From ireland.comSaturday, 22nd March, 2008

THE RAILWAY Procurement Agency (RPA) is to go ahead with a low-capacity design for Metro North, according to briefing documents circulated to the four consortiums which are bidding for the project. Tim O'Brien reports.

The agency confirmed to bidders at a specially organised "workshop" in recent weeks that it wanted to develop an underground which uses vehicles that are longer but similar in width and height to the overground Luas trams.

The Luas has already faced criticism from commentators, including Dr Garret FitzGerald, who say its current capacity problems relate to the fact that it is a lower-capacity tram system rather than a heavy-rail metro line.

However, the Green Line Luas was constructed so that it could be converted to a heavy-rail metro line by the addition of faster, wider-bodied carriages - at least from the Beechwood stop outbound.

However concern has been expressed that such an approach would not be possible under ground, unless the tunnel was constructed to a wider specification than that which has been indicated in the pre-tender advice given to the bidding companies at the workshop.

The agency's specification envisages a maximum 18,000-20,000 passengers an hour in each direction, in what would essentially be a 90m (295ft) underground tram.

In contrast, the overground Dart has a capacity of at least 36,000 passengers per direction per hour.

In a further difficulty for Metro North, its catchment area is much wider than the coastal Dart line, encompassing much of the mid-city, and taking in major installations such as the Mater hospital and its future extensions, DCU, Dublin airport and the expanding Fingal area of north Dublin.

RPA chief executive Frank Allen has said Metro North is fully compliant with population projections in the Fingal Development Plan.

However, the Dublin Institute of Technology Futures Academy has calculated that more than one million people could migrate to the Dublin-Belfast axis by 2020.

This would create additional development pressure beyond the Fingal administrative area, which would critically affect the usage projections for Metro North.

Faced with the problem, Minister for Transport Noel Dempsey has decided against asking the Railway Procurement Agency to build additional capacity in the Metro North tunnel, a feature he acknowledged would affect the cost.

However, Mr Dempsey failed to give the agency's plans his outright blessing, remarking that he "could not guarantee" that the capacity of the proposed Metro North was sufficient to meet population forecasts.

Speaking at the recent launch of plans for the CIÉ's underground Dart interconnector, which will use the wider-bodied trains, Mr Dempsey said he had been assured by the RPA that Metro North had sufficient capacity and, while he acknowledged that there were industry concerns about the issue, "the time for consultation and talking is finished".

The agency expects to issue tender documents to the bidders by May.

http://home.eircom.net/content/irelandcom/topstories/12462306?view=Eircomnet

[arkk]

The agency confirmed to bidders at a specially organised "workshop" in recent weeks that it wanted to develop an underground which uses vehicles that are longer but similar in width and height to the overground Luas trams.

So is this another rehashed article stating that metro will be a light-metro like porto and unlike the DART, or are they actually now going to use on street style trams instead of the, erm, fat ones?

[MrX]

This is *MY* tax they're spending. I would like to see a full justification of this decision published a.s.a.p.

It seems completely short sighted.

Are they just fixated on Luas trams or is there some logic to this?!

[Mark]

Its partly costs and partly the ability of the metro concept to be interoperable with the Luas.

In my opinion I believe the Red line and Lucan line and possible Rathfarnham - Liffey Junction lines (ie on street) should be 2.4 and tramlike while all other lines should be at least 2.65 if not 2.8m in width.

Length or frequency are not the issues here - its width.

[clonsilladart]

I actually think there are no Technical reason whatsoever for the RPA's blind push for Trams.
The RPA will never recommend Heavy Rail, as this skirts far too close the IE's "expertise".

Bottom line on what should be done:
- Sort out the union issues within IE (Probably an imposable task at this stage)
- Combine the RPA and IE into a single body.
- Start making proper engineering based decisions (ie Heavy Rail on Major Corridors and Luas Trams as short interconnectors)

Unfortunately it's far too late for all of this. The easy decision was made years ago when the RPA was formed.

[Mark]

The RPA will never recommend heavy rail on their corridors simply cos its too expensive and not needed.

I think the RPA felt they could not have developed another transport mode that would not integrate with either the DART or the Luas. Unfortunately it'll be to our detriment when they realise that 2.4m is just too narrow for a metro.

Originally they were going to get around this issue by curving the rolling stock body outwards but no supplier was interested in this concept. Siemens seems to be the biggest name argueing that 2.4m is too small. For comparison Porto is 2.65 and Madrid is 2.8.

[Mark Gleeson]

End of the day the simplest solution here is to allow the 4 tendering consortia to simply put their best proposal on the table

So consortia 1 might charge y but offer wider carriages with more capacity, other consortia might stay narrow and charge z, x and v respectively

What if y was the lowest cost overall? What if they will charge 10% more but promise a 6 month quicker job?

This isn't lowest cost tendering this the most economically beneficial or something similar. Sadly the passenger impact isn't considered, obviously its easy make money when the trains are stuffed to the roof, having a significant % of spare capacity doesn't go down well with bean counters, but goes down well with us since you will always fill it

And no the answer isn't 42

Can we take the tech spec stuff to the technical forum folks

[Colm Moore]

The best was to do alternatives in tendering is to get everyone to tender for both options, with one being a preferred option.

[dowlingm]

Said it before, saying it again. Leave Green Line as is except expanded to 50m trams, keep the TBM heading south from SSG into Terenure/Templeogue and down to Tallaght. No worries about compatibility, no shutdown of the Green Line to connect it to Metro North, no waste of money on Line BX.

Dig out the tunnel and rough in the stations and then add stations progressively south as funds permit.

Yes, it will cost squillions but it adds a quantum increase in capacity in an area of the city choked by buses, and gives an alternative to Green Line in terms of catchment management in the inner City. It is a reverse of the usual method of Irish transit planning - accept a minority level of transit usage and build capacity behind what little demand there is.

[Tadhg17]

Ya agree the tendering groups should put their best proposal forward for the metro and then choose the best option.

They should continue tunnelling onwards towards rathmines/rathgar or terenure, should'nt just stop in st stephens green.

[al2637]

Meant to post this yesterday but am up to my eyes in work...

From the Irish Times (article was actually about Luas... but anyway)

In relation to the capacity of the proposed Metro North, Mr Allen said this was about 20,000 passengers in each direction an hour, which he said was an "exceptionally high level of passengers". Very few cities in Europe - outside of London and Paris - had a metro line requiring a greater capacity than that, he said.

Mr Allen said he did not believe the density of population or the density of public transport would ever deliver greater passenger numbers to Metro north than its built-in capacity.

While he acknowledged the tunnel could not be expanded when built, he reminded the members of the committee that Metro west was also being developed and passengers could divert to that, along with all the new Luas lines.

To expand capacity in an underground you did not dig up the tunnel but added more lines, he said.

I have to say, I do broadly agree with this argument. Dublin is a low density city, we will benefit more from a network of low->medium capacity lines than one or 2 high capacity ones.

[Mark]

Im still of the opinion that they are leaving themselves open to capacity issues by using the narrow 2.4 width. Far too narrow.

A lot can happen in 5 years. The same was said about the Luas capacity - that it was more than enough. Its the governments plan to bring in congestion charging like London. Have they taken that into account?

[Colm Moore]

Have the specifications been made public?

"While he acknowledged the tunnel could not be expanded when built, he reminded the members of the committee that Metro west was also being developed and passengers could divert to that, along with all the new Luas lines." - not much use for DCU-Trinity.

[dowlingm]

I have to say, I do broadly agree with this argument. Dublin is a low density city, we will benefit more from a network of low->medium capacity lines than one or 2 high capacity ones.Which is why Luas Green should be left as is and another radial line (i.e. Metro North-South) used to drain some of the excess demand. That said - look at the density that has been proposed even for Dublin 4 and what is likely to appear if the docks are moved to Balbriggan.

There's always the option to run parallel surface routes beside the Metro North to help with demand, especially since it is likely to take a lengthy commissioning period before maximum peak capacity can be safely operated. Many people may dislike going underground whether through phobias, security issues or mobility issues such as out of service escalators/elevators. Others might like to continue to use transit but retain cellphone service.

Both the Yonge and Sheppard subway lines in Toronto have a parallel bus which also serves people who live in the midpoints between stations. That's the kind of coordination integrated transit authorities can bring.

[Colm Moore]

Others might like to continue to use transit but retain cellphone service.
Some systems have done deals with phone operators.

But do you really want to hear "I'm on THE METRO!!"

[dowlingm]

You're right Victor, and there has been talk about doing that here in Toronto too. I'd be happy with mobile transmitters on platforms to replace the public phones and to allow Blackberrys to check in for mail but not in the tunnels. Sometimes it can be annoying with some eejit on the streetcar telling the world and his/her mother the details of their life.

[undo]

I think mobile coverage in the tunnels is unavoidable. It's about to be allowed on planes even and people will demand it be available *everywhere*.

Whether that's a good thing or not is a separate question entirely, but I expect people will be noisy about it until it happens.

[Thomas J Stamp]

Some systems have done deals with phone operators.

But do you really want to hear "I'm on THE METRO!!"

Well a few years ago I did get out the mobile on the LU and pretend that i had great coverage and having a pretend conversation. Cue many people taking out their phones and studying the bars intently.

[Brian Condron]

Well a few years ago I did get out the mobile on the LU and pretend that i had great coverage and having a pretend conversation. Cue many people taking out their phones and studying the bars intently.

Reminds me of that great Dara O'Briain bit, take your phone out on the London Underground, pretend to receive a call and exclaim at the top of your voice "IT'S FALLEN BY HOW MUCH? SELL, SELL OH DEAR LORD SELL!". If anyone asks just say "oh we all have these phones in Ireland".

I've always thought that a great idea for a sitcom would be to just put a camera on the Luas or DART and just listen to snippets of people's telephone conversations. Can be comedy gold!

[Aphfaneire]

:( IT looks like we just have to wait for the rpa to go for the company dumb enough not to argue that we need bigger trains and bigger tunnels and will do it half arsed and cheaply.


Or we could get some genious's in with a mix of german and japanese know-how with endless coffers like the middle east and make a perfect system, if only:rolleyes:

[Mark]

2.8m width would be ideal but 2.65m/2.7m would also be achieveable given the RPA originally perceived that as their metro tram width. When you look at it, 250mm is not a huge distance and so the question is have the curve radii have been designed to 2.4 or have they allowed scope for wider body trams.

I wonder would 2.4m width units impact on comfort, especially taking into account airport patrons.

[Thomas J Stamp]

I wonder would 2.4m width units impact on comfort, especially taking into account airport patrons.

Depends if they're itsy bitsy Japs or fat Americans I suppose

[undo]

Depends if they're itsy bitsy Japs or fat Americans I suppose

Manuel Uribe might not fit on a 2.4m tram either :).

[Mark]

Depends if they're itsy bitsy Japs or fat Americans I suppose

Are you advocating separate carriages for different nationalities? :D

I was thinking more along the lines of luggage though. Has anyone here used the LU to get from Heathrow with luggage? Is it cramped?

[Mark Hennessy]

Are you advocating separate carriages for different nationalities? :D

I was thinking more along the lines of luggage though. Has anyone here used the LU to get from Heathrow with luggage? Is it cramped?

From Knight's Bridge to Barons Court is the worst as you have locals cramming on alongside the airport traffic.

No areas for luggage and very cramped.

Tubes every 2-3 mins to Heathrow though.

[Aphfaneire]

Are you advocating separate carriages for different nationalities? :D

I was thinking more along the lines of luggage though. Has anyone here used the LU to get from Heathrow with luggage? Is it cramped?

Good question the metro should be able to take airport passengers not normal commuters.

Maybe if they have the shuttle trams converted to different space arrangements compared to trams that run all the way too swords.


Or they could just build a heavy rail soloution wich could easily have the right space:p

[Mark]

I think that they are running with the right solution on the right route with stations at pretty much the best locations*. However I think sticking with 2.4m wide trams could be a huge shortcoming. The airport terminating trams will go someway to giving the Airport travellers comfort but a lot will depend on the tram design and the amount of low floor space. There isnt that much space for large amounts of luggage on the luas.

*Would still prefer O'Connell Street instead of O'Connell Bridge and Parnell.

[Colm R]

Have we any indication as to what the layout of the Dublin Airport Station will be. I have seen it somewhere before, can't remember what city but essentially what would be required is

A well publicised platform (which would be a terminating platform also) where the train would idle for 5 minutes or more. This way most once off users (as in tourists) who generally have bags, would be inclined to use this. The idling time gives a more relaxed feel for visitors and they are not lumped in with commuters from Swords and elsewhere.

Then a seperate platform for more regular users in the know with the train coming from Swords with a 20 - 30 second stopping time.

Going in the opposite direction, a more publicised train terminating at the Airport, perhaps with a specific platform in St. Stephens Green and O'Connel St. The other 'commuter' trains should not over publicise the fact that they stop in the Airport.

Anyway the above would be a dream. I don't envisage it happening that way.