[article] RPA defends capacity of proposed metro trams

[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]

Originally Posted by Mark Gleeson

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...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

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.


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.