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.
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
MJohnston wrote: » You can certainly question the practicality of the option, but the bolded is a really weak reason to do so.
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.
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.
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'.
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.
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.
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.
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.
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).
MJohnston wrote: » pedestrian overpasses
loyatemu wrote: » footbridges?
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).
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.
loyatemu wrote: » they're putting a ped/cycling underpass in as part of the Merrion Gates plan
murphaph wrote: » Obviously any crossings that can simply be closed with no major adverse affects should simply be closed.
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.
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.
blanch152 wrote: » Isn't speed a consideration also?
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.
