Merrion Gates removal scheme

4ensic15 wrote: »

Can't be much dearer than the proposal being floated. A short tunnel, even to the Jacobs building car park from the Sandymount car park would only involve some land reclamation, would not involve CPO of any free-standing buildings and would not impact on the amenities of the area. The tunnell could be built with a cut and cover approach so would be easily and cheaply done.

The Merrion Strand is a conservation area (as is the whole Dublin Bay) which I was told at the public consultation was a no-no for anything like that. Most objections were related to the loss of gardens and car parking on Merrion Rd.

The proposal for a bridge going over the railway near the Merrion Church was never going to fly and it's a crazy solution. A cut and cover tunnel running north from the Jacob's building along the seafront and joining Strand Road near Strand House seems to me to be an ideal solution. It would involve tunnelling under the railway but I believe this can be done without disturbing railway movements - I remember seeing something similar being done in Boston's Big Dig where they slid a large wide road tunnel under several railway tracks.
There would be some temporary impact on the environment but this would return to normal once works were completed. There simply has to be some flexibility with Environmental Protection Laws, if not, nothing will get done.

See attached my rough sketch showing my proposed route.

https://ibb.co/kDRizx

vrusinov

Sandymount strand floods every few years during high tides. I imagine any tunnel is no-go for this reason.

Poster King wrote: »

See attached my rough sketch showing my proposed route.

https://ibb.co/kDRizx

You want to build a cut and cover tunnel in the middle of the sea ? :eek:

The current proposal for replacing the Merrion Gates ignoring the rest is 250 m of road inc a new bridge. The existing gates are to be replaced by an pedestrian underpass. Compared with a few km of cut and cover tunnel, it is significantly cheaper, and would cause less disruption. No homes lost and little CPO.

If going for a tunnel, then go all the way from the Irish Glass Bottle site, and take all the traffic from the Frank Clarke Bridge - it would be across the strand - and then a causeway would be cheaper, with a bridge across the railway.

Crayons anyone?

A sealed buried tunnel won't let in water along its length. The southern end opening isn't at risk of flooding as it would be set back from the sea and be protected by the railway line and a sea wall, the northern opening might possibly be at risk of some flooding during very high tides combined with an easterly storm, but protections could be put in place at that location and in extreme very rare situations the tunnel might have to be closed and traffic rerouted by Sydney Parade. Strand Route itself doesn't flood that much, what floods is the below sea level land to the West of it.
I'd be very interested to know if the cut and cover tunnel option was ever even considered or did someone just say "No can do - would be in breach of ridiculously strict and inflexible environmental protection laws"

LeinsterDub wrote: »

You want to build a cut and cover tunnel in the middle of the sea ? :eek:

Yes, very easily done I believe. You build a temporary sea wall using metal panels that are piled into the ground, then you dig your trench, then you insert concrete 'tubes' which are totally sealed, then you fill back in the hole and cover with sand/beach.

Sam Russell wrote: »

Compared with a few km of cut and cover tunnel, it is significantly cheaper, and would cause less disruption. No homes lost and little CPO.

It would be 550m of tunnel, NOT a few km. The tunnel option would cause a lot less long term disruption and NO homes would be lost to CPO. The only thing that might have to go is a Petrol station (these will be obsolete in a few years anyway) and maybe a a couple of meters of grass and car park from St Mary's Nursing home so that Merrion Road could be realigned/widened to make room for a new junction.

Poster King wrote: »

Yes, very easily done I believe. You build a temporary sea wall using metal panels that are piled into the ground, then you dig your trench, then you insert concrete 'tubes' which are totally sealed, then you fill back in the hole and cover with sand/beach.

Budget blown, environment ruined, cycle lane not implemented.
Other than that completely feasible

LeinsterDub wrote: »

Budget blown, environment ruined, cycle lane not implemented.
Other than that completely feasible

A little negative thinking there. The budget just might have to be increased, this problem needs to be solved once and for all, and they shouldn't try and pass this off as part of the coastal cycle route. This is a major piece of very necessary infrastructure whcih will reduce traffic congestion but much more importantly it will allow for significant increase in train frequency.

I don't believe the environment would be "ruined". A very small strip of beach will be impacted for a period of probably 3 years, the environment will adapt and return to it's previous state very quickly and once the job is complete the tunnel will be hidden and it will have far less visual impact than a bridge.

And as regards the very important cycle path, this can very easily be incorporated into this scheme. You make the tunnel under the railway wide enough to accommodate a cycle path and then have this cycle path come back to the surface immediately on the sea side of the railway line via a ramp, then the cycle lane continues north along the now very quiet section of Strand Road.

Poster King wrote: »

I don't believe the environment would be "ruined". A very small strip of beach will be impacted for a period of probably 3 years, the environment will adapt and return to it's previous state very quickly and once the job is complete the tunnel will be hidden

I think hold the EPA, NTA and EU's opinion in higher regard that someone who's just said "awh sure it will be grand" on the internet.

josip

Go Dutch and build a dyke from Poolbeg to Seapoint.

Sell the reclaimed land to developers.
Houses for everyone.
Surface level Eastern Motorway.
Keep some of the proceeds to pay the EU fines and the court challenges from twitchers.
Regret it all in 50 years time for some reason.

prunudo

A road tunnel sounds like a hugely over engineered solution to a pretty simple problem.

josip wrote: »

Go Dutch and build a dyke from Poolbeg to Seapoint.

Sell the reclaimed land to developers.
Houses for everyone.
Surface level Eastern Motorway.
Keep some of the proceeds to pay the EU fines and the court challenges from twitchers.
Regret it all in 50 years time for some reason.

No need for DU either build an entirely new surface level line.

4ensic15

LeinsterDub wrote: »

Budget blown, environment ruined, cycle lane not implemented.
Other than that completely feasible

What budget ruined. Going under the beach does not ruin the environment. No effect on the cycle lane. Don't dump your bicycle clips yet.

4ensic15 wrote: »

What budget ruined. Going under the beach does not ruin the environment. No effect on the cycle lane. Don't dump your bicycle clips yet.

The budget for this project. A tunnel would be many multiples more expensive.
The beach will be dried out for several years , neither you or I would know what's living their we just know it's protected. I would assume for a good reason.
So we are still building the tunnel under the DART line?
I don't own clips?

4ensic15

LeinsterDub wrote: »

The budget for this project. A tunnel would be many multiples more expensive.
The beach will be dried out for several years , neither you or I would know what's living their we just know it's protected. I would assume for a good reason.
So we are still building the tunnel under the DART line?
I don't own clips?

A tunnel can't be more expensive than paying numerous D$ landowners compensation. Why would the beach be dried out? Nothing living there would be killed, it would just be shifted slightly. You are just scaremongering.

marno21

4ensic15 wrote: »

A tunnel can't be more expensive than paying numerous D$ landowners compensation. Why would the beach be dried out? Nothing living there would be killed, it would just be shifted slightly. You are just scaremongering.

Unfortunately, such a proposal would be ok in the 1970s but not nowadays. There are several EU directives which will stop any attempt to disturb the seafront. The only viable option is the option the NTA have chosen

4ensic15

marno21 wrote: »

Unfortunately, such a proposal would be ok in the 1970s but not nowadays. There are several EU directives which will stop any attempt to disturb the seafront. The only viable option is the option the NTA have chosen

If the entry and exit are on land and the tunnel is under the beach there would be no disturbance of the seafront.

Green Party: Ossian Smyth

4ensic15 wrote: »

A tunnel can't be more expensive than paying numerous D$ landowners compensation. Why would the beach be dried out? Nothing living there would be killed, it would just be shifted slightly. You are just scaremongering.

The original project was priced to include the compensation.
You've to dry the beach if you want to build a cut and cover tunnel. If you're talk TBM then it's several multiples more again.

How would you shift the marine wildlife?

I'm not scaremongering unless you've a marine biology degree then you don't know what will happen where as I'm basing my opinion on what the NTA have said.

I want to see the S2S go ahead whether or not this flyover is built. Later this month, I am meeting with the NTA, Irish Rail and other pro-S2S elected representatives from all parties to see how we can progress this. I would like to see the DART moved to a 10-minute frequency. The S2S public consultation was started in late 2016 and my fear is that the NTA is losing interest in urban greenway projects in Dublin (river, canal, coastal) with a view instead to designing cycle lanes tacked on to revamped bus lanes as part of Bus Connects. Bus Connects is likely to announce the road infrastructure stage of their project in June.

A report on grade-separated alternatives to a level-crossing is here:
http://www.ossiansmyth.ie/wp-content/uploads/2018/04/s2sPart_D_Appendices.pdf

They looked at two tunnel options and several other choices.

and their preferred option:

Bray Head

On the basis of those options it's fair to say that:
-The selected route is the least obtrusive visually and least environmentally disruptive.
-The selected route will carry the least volume of traffic - T-junction with traffic lights on the Merrion side will be slower than the grade-separated slip roads.

Middle Man

Just grade separate the railway and don't disturb the shoreline - to hell with property - I'd even four track the line if I could get away with it.

The preferred option will not cause less traffic flow, because at PM busy times, the back-up is all along the Rock Road and backs up to the Canal.

The existing setup has a slip road that does not work because the traffic is already backed up and the sight lines for traffic is all wrong.

I would modify the preferred solution by making it an underpass rather than a bridge as it would reduce the visual impact while not impacting the design much. I]The road has to rise or fall by 5m to clear the railway or to allow clearance under the railway[/I.

It should go ahead without the cycling and bus lane options in the interim as most complaints are about the effects on property. The underpass at the existing Merrion Gates could be constructed as part of the cycling infrastructure.

If built, Sydney Parade LC would be basically for local access.

Claw Hammer

I would close the Merrion gates completely. I would continue the curtain walls around the rail track in place of the gates. That would turn the end of Strand Road into a cul de sac. Problem solved. Cost about 10K.

vrusinov

How to you propose traffic from south get to east point in this case?

Remember this includes public transport like those long aircoach buses.

Claw Hammer

vrusinov wrote: »

How to you propose traffic from south get to east point in this case?

Remember this includes public transport like those long aircoach buses.

On the public roads. It is just one less option. Nobody would be cut off from anywhere.

NuMarvel

Claw Hammer wrote: »

On the public roads. It is just one less option. Nobody would be cut off from anywhere.

One of the most notorious bottlenecks in the city, and you think we can just redirect the traffic to other roads with no ill effects?

Riiiiight.....