DART+ (DART Expansion)

Sam Russell · 28-02-2018 9:38pm

The bridge through the carparks has been proposed and has been to public consultation. The result is awaited.

The other two have zero chance of happening as they pass through very expensive property owned by well connected folk.

I do not think so.

strassenwo!f · 01-03-2018 1:55am

MJohnston wrote: »

I think Serpentine Ave is the one specifically that they're going to have to leave open and fix. Arguably once the Merrion Gates crossing is fully separated, Sydney Parade Ave is served well enough by that, and Lansdowne by Bath Ave, but you probably need Serpentine to have something in that 3km gap, at which point Sandymount Ave could be closed.

The problem is the physics of the situation. The only solution I can think of that wouldn't involve large-scale CPOing would be a very tight road bridge using Serpentine Terrace and Oaklands Park (1 house CPO'd) - but I don't know how practical this would be, and whether they'd just prefer to keep the crossing.

One would certainly question the practicality of that option.

Two quiet roads in a Dublin suburb, with that possibility foisted upon them.

It is probably doubtful that we need further discussion of this idea

MJohnston · 01-03-2018 2:02am

strassenwo!f wrote: »

One would certainly question the practicality of that option.

Two quiet roads in a Dublin suburb, with that possibility foisted upon them.

It is probably doubtful that we need further discussion of this idea

You can certainly question the practicality of the option, but the bolded is a really weak reason to do so. First, there's nothing sacrosanct about the 'quietness' of streets. Second, it's hardly that anyway, being 100m away from the main road:

markpb · 01-03-2018 11:10am

MJohnston wrote: »

You can certainly question the practicality of the option, but the bolded is a really weak reason to do so.

And third, you have to find a balance between the needs of the double digit numbers of people affected versus the teens of thousands of people who could benefit from it.

Sam Russell · 01-03-2018 11:23am

markpb wrote: »

And third, you have to find a balance between the needs of the double digit numbers of people affected versus the teens of thousands of people who could benefit from it.

Traffic is like water, it finds its own level. Closing the LC gates will cause people to go around 'the long way'. Grand Canal Quay bridge was closed some tme ago without any problem. It was only a low bridge fit just for cars, but closed none the less.

If the LC remains open, but closed 50% of the time for trains then it will not get much traffic outside local residents if alternatives exist. Only if 5 min Darts are proposed, then they will remain as is. Merrion Gates LC is the major problem, not the others.

no.8 · 01-03-2018 1:04pm

Khuitlio wrote: »

I reckon if you really wanted to get rid of the level crossing you could build these three road bridges and have them all closed.

Interesting. Nice work.

My opinion is that it may not be cheap, but it would be far more practical to build underpasses on the 1st 2 options. I mean the 1st option would be unacceptable in terms of the scale any proposed bridge. Plus for locals there would be far less to complain about, in terms of obstructions of views, wider impact etc. etc.

The main advantage is that you can keep the same alignment and provide access for pedestrians/cyclists. Again, major project but far less 'collateral damage'.

Sam Russell · 01-03-2018 1:24pm

no.8 wrote: »

Interesting. Nice work.

My opinion is that it may not be cheap, but it would be far more practical to build underpasses on the 1st 2 options. I mean the 1st option would be unacceptable in terms of the scale any proposed bridge. Plus for locals there would be far less to complain about, in terms of obstructions of views, wider impact etc. etc.

The main advantage is that you can keep the same alignment and provide access for pedestrians/cyclists. Again, major project but far less 'collateral damage'.

The Merrion Gates replacement in the two car parks would work well as an underpass as there is enough approach to drop the road under the line, and would reduce the visual impact of the proposed scheme.

The time to tackle the Lansdowne Road LC was when they were building the new stadium. That train has left the station.

In the case of any of the others, none of these are proposed by any official body. That makes them unlikely to progress. It is more likely that they will simply be closed or left as they are.

strassenwo!f · 02-03-2018 12:19am

I think it would be a good idea to rejig this thread, if it's possible.

The vast majority of the thread was about the DART Underground tunnel, but that doesn't now seem to be on the agenda for the moment. On the other hand, as the thread title suggests, overground DART expansion, in conjunction with the Phoenix Park tunnel, is very much on the agenda.

I think it would be a pity if a lot of the stuff written about the DART Underground project over the last decade or so were to be effectively lost because the focus is now on something different.

I would suggest going back to the point some months ago where the various threads were amalgamated, separating them, and then locking the 'DART Underground' thread until that project comes back on the agenda.

If it eventually comes back, as I hope it will, the conversation about the cross-city tunnel can then resume, pretty much uncluttered by what's going on in outlying parts of the metropolitan area.

murphaph · 03-03-2018 7:23am

It amuses me how a few level crossings present an almost impossible engineering feat, seemingly with no solution.

Just raise the railway over those crossings. One side at a time. That's what signals are for. Terminate "inter city" trains at Bray until the works conclude.

There are flyovers and raised sections of heavy rail all over Berlin.

MJohnston · 03-03-2018 12:15pm

murphaph wrote: »

It amuses me how a few level crossings present an almost impossible engineering feat, seemingly with no solution.

Just raise the railway over those crossings. One side at a time. That's what signals are for. Terminate "inter city" trains at Bray until the works conclude.

There are flyovers and raised sections of heavy rail all over Berlin.

Good for Berlin - there are dozens of raised sections of heavy rail in Dublin too, in case you've forgotten! Nobody is claiming this is an impossible engineering feat, though if you've lived in Germany for a long time, it would be no surprise if you can only think in engineering terms!

But it's not as simple as just the engineering part of it. Adding raised sections would be expensive, it would encounter a lot of NIMBY resistance (especially in an area like D4). But the biggest thing is that in some of the cases, it wouldn't be worth it - you could close Sandymount Avenue to traffic today, for example, and it'd be a much better decision than trying to build a flyover or raised section.

Sam Russell · 03-03-2018 2:50pm

murphaph wrote: »

It amuses me how a few level crossings present an almost impossible engineering feat, seemingly with no solution.

Just raise the railway over those crossings. One side at a time. That's what signals are for. Terminate "inter city" trains at Bray until the works conclude.

There are flyovers and raised sections of heavy rail all over Berlin.

There are five level crossings that only one has a official proposed solution and that is the most important one - Merrion Gates. The solution is imaginative but has raised huge objections from NIMBY locals. If that were implemented, the one at Sydney Parade becomes less significant, and could be left as is (and risk being closed for more than 50% of the time. I think that would be OK with the locals.

Raising or dropping the railway line would be hugely expensive and require the line to close for at least six months, possible two years. The three stations involved would need to be rebuilt completely. It would be better to build a new line out at sea than that.

These LCs have no easy solution - too many buildings too close to the railway.

strassenwo!f · 03-03-2018 11:41pm

Sam Russell wrote: »

Traffic is like water, it finds its own level. Closing the LC gates will cause people to go around 'the long way'. Grand Canal Quay bridge was closed some tme ago without any problem. It was only a low bridge fit just for cars, but closed none the less.

If the LC remains open, but closed 50% of the time for trains then it will not get much traffic outside local residents if alternatives exist. Only if 5 min Darts are proposed, then they will remain as is. Merrion Gates LC is the major problem, not the others.

The last point here, that the Merrion Gates level crossing is the major problem, is very important to bear in mind.

Given that much, or most, of the southside DART line only has a catchment area on one side of the line, there is no pressing need to do anything to upgrade it, apart from Merrion Gates, which is the key route to and from the East-Link toll bridge.

Dublin has many more important things to deal with, in areas where there would be a potentially very significant catchment area on both sides of any proposed railway line.

murphaph · 05-03-2018 12:22am

Sam Russell wrote: »

There are five level crossings that only one has a official proposed solution and that is the most important one - Merrion Gates. The solution is imaginative but has raised huge objections from NIMBY locals. If that were implemented, the one at Sydney Parade becomes less significant, and could be left as is (and risk being closed for more than 50% of the time. I think that would be OK with the locals.

Raising or dropping the railway line would be hugely expensive and require the line to close for at least six months, possible two years. The three stations involved would need to be rebuilt completely. It would be better to build a new line out at sea than that.

These LCs have no easy solution - too many buildings too close to the railway.

You wouldn't need to close the up and down lines. You do one at a time. You drive a steel retaining wall into the ground and work on one side. The other side has single line running.

There's single line running on some stretch of the Berlin ubahn (and any other major mass transit system in the world, lest some people get their knickers in a twist about a German example-didn't realise this had become like the comments section of the Daily Express!) probably every day. It's what signals are for.

We raised the N25 (now N40 I believe) over the roundabouts without shutting it.

The only issue here is nimbyism. But if you bought a property adjacent to a railway you have to accept it may see development.

Sam Russell · 05-03-2018 10:03am

murphaph wrote: »

You wouldn't need to close the up and down lines. You do one at a time. You drive a steel retaining wall into the ground and work on one side. The other side has single line running.

There's single line running on some stretch of the Berlin ubahn (and any other major mass transit system in the world, lest some people get their knickers in a twist about a German example-didn't realise this had become like the comments section of the Daily Express!) probably every day. It's what signals are for.

We raised the N25 (now N40 I believe) over the roundabouts without shutting it.

The only issue here is nimbyism. But if you bought a property adjacent to a railway you have to accept it may see development.

There are three stations affected. They would need to be rebuilt so what do you do in the meantime? They do have the facility to run single line working as it is - they were doing so after the weather shutdown, but the current platforms, and pedestrian bridges would need re-configuring. It would be a massive undertaking - and a bit more than NIMBYism would object. There would be the option of dropping the line, but that is just as big an undertaking.

Merrion Gates is being planned, but after that it is a case of live with the remaining level crossings or close them.

no.8 · 05-03-2018 10:16am

murphaph wrote: »

It amuses me how a few level crossings present an almost impossible engineering feat, seemingly with no solution.

Just raise the railway over those crossings. One side at a time. That's what signals are for. Terminate "inter city" trains at Bray until the works conclude.

There are flyovers and raised sections of heavy rail all over Berlin.

Interesting proposal.
I think the implementation of underpasses presents a far more feasible solution. Raising kilometers of trackbed vs. lowering several hundred metres of roadway (for 3 crossings). There are countless examples of urban configurations throughout Europe and possibly Ireland.
Low impact and ensure high-traffic flow + you don't affect the performance of the track (e.g. if heavier locomotives might struggle etc....depending on the gradient).

Sam Russell · 05-03-2018 10:35am

no.8 wrote: »

Interesting proposal.
I think the implementation of underpasses presents a far more feasible solution. Raising kilometers of trackbed vs. lowering several hundred metres of roadway (for 3 crossings). There are countless examples of urban configurations throughout Europe and possibly Ireland.
Low impact and ensure high-traffic flow + you don't affect the performance of the track (e.g. if heavier locomotives might struggle etc....depending on the gradient).

There are five crossings - but proposals for Merrion Gates so assume that one is dealt with.

An underpass might work for some, but height clearance might need to be restricted to allow just cars. The problem is access to houses on the approach to the underpass - the deeper you go the more properties effected.

However, I think the problem (other than Merrion Gates) is not worth the solution.

MJohnston · 05-03-2018 12:36pm

Exactly - this is mostly overengineering. There isn't enough distance between the remaining 4 crossings, excluding Merrion Gates, to justify a massive engineering project like an overpass or an underpass. As I mentioned before, you could probably make a case for retaining the Serpentine Avenue crossing as it's right in the centre of the 3km between Merrion and Bath Avenue that should otherwise be closed to traffic, and I'd build some simple pedestrian overpasses where necessary at other closed crossings.

loyatemu · 05-03-2018 1:19pm

MJohnston wrote: »

pedestrian overpasses

footbridges?

Sam Russell · 05-03-2018 1:28pm

loyatemu wrote: »

footbridges?

Well, it might require a lift or two, or a very long ramp for disability reasons.

loyatemu · 05-03-2018 1:35pm

they're putting a ped/cycling underpass in as part of the Merrion Gates plan - will they be able to do that without closing the line (I have a recollection they put underpasses in at Woodbrook Golf Course without significant closures).

Sam Russell · 05-03-2018 3:16pm

loyatemu wrote: »

they're putting a ped/cycling underpass in as part of the Merrion Gates plan - will they be able to do that without closing the line (I have a recollection they put underpasses in at Woodbrook Golf Course without significant closures).

That whole project has gone quiet.

murphaph · 05-03-2018 5:58pm

Obviously any crossings that can simply be closed with no major adverse affects should simply be closed. But I don't buy the whole "this is a major undertaking".

We've constructed many more challenging features on our road network in the past 20 years.

Sure there would be some disruption but the line would not have to be closed to raise or lower it one side at a time.

Sam Russell · 05-03-2018 6:27pm

murphaph wrote: »

Sure there would be some disruption but the line would not have to be closed to raise or lower it one side at a time.

There are three stations impacted. If you drop or raise the line by 5 m, then what do you do about the platforms? How do passengers manage to get from one side to the other? It would of course cost more for little benefit.

Any idea of cost?

loyatemu · 06-03-2018 11:08am

loyatemu wrote: »

they're putting a ped/cycling underpass in as part of the Merrion Gates plan - will they be able to do that without closing the line (I have a recollection they put underpasses in at Woodbrook Golf Course without significant closures).

not sure if this has been linked earlier in the thread, but interesting Engineers Ireland presentation on closing level crossings that includes details of the Woodbrook underpasses mentioned above:

https://www.engineersireland.ie/EngineersIreland/media/SiteMedia/groups/societies/project-management/level-crossing.pdf?ext=.pdf

LeinsterDub · 06-03-2018 11:42am

loyatemu wrote: »

they're putting a ped/cycling underpass in as part of the Merrion Gates plan

They'd want to considering it's coming out of the cycling infrastructure budget

strassenwo!f · 07-03-2018 12:42am

murphaph wrote: »

Obviously any crossings that can simply be closed with no major adverse affects should simply be closed.

Why?

Obviously Merrion Gates is an enduring problem which needs to be dealt with, but closure of the others would seem to create more problems than it solves, with the necessity to put in tunnels or footbridges to retain pedestrian access at the least.

At the moment it's something like 8 trains per hour in each direction, at peak times. Even if you got rid of all the level crossings there is never going to be demand for more than a 5 minute service along that route, because of its geography, and that would still allow some time at peak times for road traffic to cross between the main body of the city and that chunk of land in Sandymount/Irishtown.

At non-peak times - when there's a service around 15-20 minutes in each direction along that section - or at night, when there is no service, there is no problem encountered at these level crossings. Apart from the Merrion Gates problem there is no issue here, and no reason for money to be spent.

lucernarian · 07-03-2018 8:44am

strassenwo!f wrote: »

Why?

Obviously Merrion Gates is an enduring problem which needs to be dealt with, but closure of the others would seem to create more problems than it solves, with the necessity to put in tunnels or footbridges to retain pedestrian access at the least.

At the moment it's something like 8 trains per hour in each direction, at peak times. Even if you got rid of all the level crossings there is never going to be demand for more than a 5 minute service along that route, because of its geography, and that would still allow some time at peak times for road traffic to cross between the main body of the city and that chunk of land in Sandymount/Irishtown.

At non-peak times - when there's a service around 15-20 minutes in each direction along that section - or at night, when there is no service, there is no problem encountered at these level crossings. Apart from the Merrion Gates problem there is no issue here, and no reason for money to be spent.

Irish Rail are eager to have the Porterstown crossing closed, presumably because there's real benefits to having even quiet level crossings closed.

Safety issues stand out as a compelling reason, along with operational reliability. When I was stuck on a train because of a fault, it took about half an hour to get us moving again.

Those two reasons alone show how some money deserves to be spent on tackling those issues.

blanch152 · 07-03-2018 12:29pm

lucernarian wrote: »

Irish Rail are eager to have the Porterstown crossing closed, presumably because there's real benefits to having even quiet level crossings closed.

Safety issues stand out as a compelling reason, along with operational reliability. When I was stuck on a train because of a fault, it took about half an hour to get us moving again.

Those two reasons alone show how some money deserves to be spent on tackling those issues.

Isn't speed a consideration also?

MJohnston · 07-03-2018 12:43pm

blanch152 wrote: »

Isn't speed a consideration also?

It is, but as Sam Russell pointed out, there are stations right beside nearly every level crossing on the south DART section we've been discussing, which means trains would be slow anyway. Similar at somewhere like Clonsilla too.

Sam Russell · 07-03-2018 1:32pm

MJohnston wrote: »

It is, but as Sam Russell pointed out, there are stations right beside nearly every level crossing on the south DART section we've been discussing, which means trains would be slow anyway. Similar at somewhere like Clonsilla too.

Well, yes there are stations at three of the LCs but not at Sandymount Ave. However, not all trains stop at all stations. Diesels do not stop at Sandymount, and many do not stop at Lansdowne or Sydney Parade.

Also, there is not consistent speed of any trains - some race by and some creep by.

DART+ (DART Expansion)

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