Liffey Crossings

gobdaw

On Platform11 forum, mention was made of the cost of bridging the Liffey for MetroWest.


The original West link bridge was designed as a square concrete tube – i.e. upper deck (road deck), lower deck and two sidewalls. At it’s opening, NTR boasted that the tube, or void, was big enough to fit a train. Such a bridge (metro on the lower deck with the upper deck a roadway) exists in Prague, crossing a wide urban “canyon”. It is called Nuselsky Most.



Between Islandbridge and Lucan there is a shortage of river crossings of the Liffey, Chapelizod being the sole road bridge. Late last year, some Chapelizod residents were urging the closure of the village to through traffic.


Should the powers-that-be not consider the provision of such a dual bridge to address the relatively short-haul traffic movements, without excessive additional public expenditure in the event of the creation of MetroWest?[SIZE]

Victor

"Apparently" the Westlink bridges have too many obstructions, phone cables amonst others.

murphaph

Gobdaw, you're absolutely right of course but here in Ireland it's arseways. Fingal Co Co (rightly IMO) claim that if the outer ring road were to go ahead today (a bridge would be required from near Woodies in Lucan to cross the valley and land you near Porterstown in Clonsilla) then purely to avoid a toll, many would divert OFF the M50 to use this new route. You can't argue with that and so they canned the ORR inside Fingal (hence it stops at Woodies now!). If there was no toll then the ORR could proceed as originally planned. Unfortunately ANY new (decent quality high level) crossing of the Liffey Valley will attract people who do not wish to pay (can't really blame 'em either) and so any such bridge remains controversial, notwithstanding the whole 'scenic beauty' of the Valley which should of course be maintained as far as possible.

So, if we want new crossings (which are badly needed in west Dublin) then the toll will have to go first. Not likely. As I said, arseways. If it were another country you could build two more crossings and then watch NTR drop their prices to attract business back onto theirs. Then some people would return to the M50 one.

godtabh

Where did you hear that a train could fit through the bridge?

Just by looking at it I wouldnt have thought that a train would've fitted throught it.

Plus I would saw that most of the servies that run through the bridge would go through the hollow core of the deck and the only thing the lower deck could be used for would be service people.

I'm not sure if the river corssing at Woodies would be a good idea. I think you would be just moving the bottle neck else where

gobdaw

kearnsr wrote:

Where did you hear that a train could fit through the bridge?

Just by looking at it I wouldnt have thought that a train would've fitted throught it.

As part of the original bridge lanch publicity, NCR boasted that the void was big enought for a train. I dont know what the actual internal dimentions are, but undoubtedly they would be sufficient to provide an alternative road route from Carpenterstown to Palmerstown Interchange. The road works would caused mayhem at the Pay Plaza and Palmerstown in the short term, but so will the widening of the M50 cause mayhem

Murphaph – your right. M50 is chicken ‘n’ egg stuff. It is not able to cater for the volume of traffic currently, yet it seems to be a problem opening another cross Liffey route, because that would reduce the income of NTR. This despite the fact that actual traffic demand hugely exceeds projected demand.

Who is running the asylum? We must, by now, be at the stage of either buying out NTR or providing competition, a la PDs and Mary Harney.

South Dublin has proposals for an Outer Ring Road from Grange Castle to Tallaght By-pass. Does Fingal have any proposal to link to this?

gobdaw

Sorry, Phillip, I see you are saying that Fingal have no plans. I feel sorry for Lucan, so.

murphaph

The ORR was originally planned under the auspices of what was Dublin County Council. The bits that remain on the drawing board include N81-N4 (SDCC section) and Porterstown-Dublin Airport (FCC section) but the vital link has been removed from the FCC development plan for the reasons cited.

They have an alternate crossing in the current development plan which will connect Ongar in D15 to the current J2 on the N/M4 at the Spa Hotel, crossing over the Lifey Valley of course. They reckon it's distance from the Westlink will mitigate the effects of people 'dodging' the (punitive) toll.

They should be looking to build BOTH bridges. West Dublin is currently getting by with a medieval roads network, linked by bits and pieces of new infrastructure yet West Dublin is expected to house hundreds of thousands of new citizens over the coming decades (Adamstown and Hansfield SDZs for starters, Balgaddy and swathes of land west of Adamstown will likely be heavily developed also). West Dublin NEEDS more norh-south routes, brand new ones at that. They will require Liffey crossings. This is not admitting the M50 has failed or anything like it. It's admitting the reality that Dublin West is the growth centre for population in Ireland for the coming decades.

Victor

gobdaw wrote:

As part of the original bridge lanch publicity, NCR boasted that the void was big enought for a train.

NTR maybe?

www.ncr.com

gobdaw

Touche

dowlingm

I go over the Prince Edward Viaduct every day.

Designed in 1913 with lower level trains accounted for from the original design - the first train ran over it 53 years later.

That's forward planning.

Archeron

Does anyone know if the idea to close Chapelizod to through traffic is actually going ahead? Its been a while since I was up that way, but when I was, local stores didnt seem too happy about the idea with signs up advising people to block the proposal.

gobdaw

Archeron wrote:

Does anyone know if the idea to close Chapelizod to through traffic is actually going ahead?

Word in Blanch has it that its is dead in the water, but I've seen nothing official.

Winters

Dont be surprised if metro west crosses the Liffey directly from the Fonthill Road.