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

Just wanted to clear up the issue relating to the cost of MN. Reports suggest that tenders from the selected consortia are coming in over €2bn. This would be the initial cost which is paid for by the winning consortium. The total cost to the government over the life of the PPP contract, which I think is 25 years, would be €5 - 6bn. This is including interest and the winning consortium would also be operating and maintaining the service.

A good article which I linked before (http://www.businessandfinance.ie/index.jsp?p=366&n=372&a=1447) says the the cost to the State between now and the day it opens will be about €100. It will then cost about €150m to €170m a year each year for 25 years afterwards. The article also makes a good point about the project employing 5,000 to 6,000 people, most of whom would otherwise be unemployed, reducing social welfare payments as well as generating a lot of tax revenue.

As with most PPP projects I think the real value to the state will be when the current contract expires, by which time most of the costs will (hopefully) be covered by the social and economic benefits arising from the project, and future contracts for operating the service will be profitable for the government, who ever that may be.

Any news on when An Bord pleanala will decide on the project?

and not building the boxes at least for the IC is too,.

Wouldn't it be a better idea and save a lot of money to not build MN underground the whole way since Luas BXD is already proposed?

Basically, axe MN from Stephen's Green entirely. Build BXD as planned from start to finish.
Then, from the Grangegorman stop of BXD, some of the trains continue on to Boombridge while some cars verge off to the right and go underground from there to the Mater stop as shown below (excuse my quick and crude photoshop) and the rest of the MN route as planned - i.e. above ground at DCU.

Edited Map (it is a solid blue line, but it represents a tunnel):





An idea of where there is ample room to begin a tunnel:





Showing the rest of the stops post Mater:

MYOB wrote:

As when someone else, or possibly you on another thread? suggested this before: No. There aren't enough slots, doing that would massacare service on MN.

That's a circular argument. If BXD ran in a tunnel with Metro North, it would be just as fast, obviously, and your argument would be moot.

Metro North does not need 30 trains per hour. 12-20 trains per hour at peak, and 8-12 off peak would be way more than adequate for the next 20 years. It has a capacity of 40 trains per hour, and more if better signalling is used.
With 10 trains per hour, it can match the peak hour capacity of the current DART line.

There is clearly plenty of room to route 8-15 BXD trams per hour down the Metro North tunnel.

I would say that this is only worthwhile if line B joined the tunnel at Stephen's Green, and BXD joined Metro North underground at Parnell square with a grade separated junction, and it could well be cost prohibitive, but the capacity in the tunnel will not be an issue for years and years to come. Look at the Oslo metro - very similar to the planned Metro North, with 3 branches feeding into a single tunnel at each end.

If Metro North is extended south to Terenure via Harold's cross, and Luas B uses the tunnel, we start moving towards a metro/ fast light rail network rather than a single line.

The point is that the city centre tunnel is by far the most expensive bit - if it is built, it should be sweated for all the use it can give as soon as possible. If it is not too expensive, they should of course link B and BXD through Metro North. There is rakes of capacity.

Cool Mo D wrote: »

I would say that this is only worthwhile if line B joined the tunnel at Stephen's Green, and BXD joined Metro North underground at Parnell square with a grade separated junction, and it could well be cost prohibitive, but the capacity in the tunnel will not be an issue for years and years to come. Look at the Oslo metro - very similar to the planned Metro North, with 3 branches feeding into a single tunnel at each end.

If Metro North is extended south to Terenure via Harold's cross, and Luas B uses the tunnel, we start moving towards a metro/ fast light rail network rather than a single line.

The point is that the city centre tunnel is by far the most expensive bit - if it is built, it should be sweated for all the use it can give as soon as possible. If it is not too expensive, they should of course link B and BXD through Metro North. There is rakes of capacity.

I dont think it would be possible because the tunnel mouth would have to be very large to allow a reasonable gradient for trams to come up from 20m below the surface to street level. Basically you would have to dig out all of St Stephens Green to allow for this. Thats why tunnel mouths are outside the city centre and run underground beneeth the city.

Aard wrote: »

I would think that a turnback facility at Drumcondra, despite its expense, would prove useful. If every 3rd train ran from SSG to Drumcondra, then came back, the central tunnel would have the high frequency it needs. It would give people in town, and transfer-commuters to Drumcondra a high-frequency, while not "wasting" trains by going further out of the city.

I like the idea of a turnback facility, would make sense to concentrate trains in the city centre instead of sending every one out to whereever the last stop is. Maybe the turnback facility should be somewhere around Ballymum, when the trains come above ground. Its not that much further than Drumcondra and would be a lot cheaper and easier to have it above ground, plenty of space out there as well Im sure.

Aard wrote: »

AFAIK, there is bored-tunnel all the way from SSG to DCU, then cut-and-cover until the M50. That'd be more than twice the distance from Drumcondra.

Not sure whats thats supposed to mean. I was agreeing with you that a turnback facility to allow higher frequency close to the city centre is a good idea instead of sending every train out to Belinstown. But having it at Drumcondra would be to expensive as you would have to bore out a large area. I suggested having it somewhere around Ballymun when the track comes above ground, so at Northwood or Dardistown stops because there would be no boring involved and it would be a lot cheaper. I know these places wont need the high frequency service, but its the most cost effective way of providing a high frequency service for the city centre and the surrounding area.

ilovegermany wrote: »

Given that Metro North, as proposed, includes an underground station and turnback facility at St. Stephens Green - if in future years the Metro was extended southwards - would there still have to be a huge amount of disruption at the Green area? Or would they just need a place to extract/insert the tunnel boring machines (TBM)?

I heard that they're actually leaving the TBM's in place, and stripping the removable parts, as it's cheaper than tunneling to the surface to take the lot out.

ilovegermany wrote: »

Seriously, is that true?

I don't know about MN but it's certainly not an uncommon scenario.

Cool Mo D wrote: »

What I would like to see in the far, far distant future, if Metro North is built and planned to be extended, is to extend Metro North, AND link in the green Luas.

Extend Metro North towards Terenure, but have it cross the Green line near Ranelagh. The Green line would enter the Metro North tunnel here, and both Metro North trains and the Green line would run under the city in the main Metro North tunnel. The Green line trams would then surface near Parnell square, and head towards Broombridge/Finglas, and Metro North would continue to the Airport.

Im not an engineer but I very much doubt this would work because I dont think it would be possible to have tunnel portals in Ranelagh or Sarnell Square. The tunnel portals need a lot of space because the trams have to come up from a depth of about 20m at a reasonable gradient. The opening would have to be quite large and the area above the tunnel before it reaches the surface would have to be free of foundations which could be undermined. There is no way this could happen in the city centre and I dont think there is a big enough space in Ranelagh.

ilovegermany wrote: »

Thanks BluntGuy - I know that all the transport plans etc call for the Metro to be extended along the Sandyford Luas line, but do you think it would probably make more sense to eventually run the metro through a few new stations and then link further out around Dundrum - with the metro taking over the existing luas line from there and the luas veering off to serve Churchtown/Rathfarnham?

This would make sense, underground stops at Rathmines and Terenure before it comes above ground to link to the existing line. Should be more space to have the tunnel portal out here. Some of the stops on Line B1 seem quite close together, would this prevent the metro trams from using them and would the platforms be big enough? Also it would need a turnback facility to allow high frequency around the city centre, like Aard suggested for the northern section above. Would there be room for this at Sandyford allowing high frequency trams between Sandyford and the airport?