Double Track - North Dublin

PS I am not an expert on these matters but could a third track be added with with relative ease as opposed to a full doubling of tracks. Direction could be swapped depending on time of day!

A bi-directional third track was a previous plan that was considered much easier to deliver. Don't know the corridor and its constraints well enough to say whether it's still a plausible idea. I think an airport spur was accessed from the third track as well. It was ended to service intercity with the double track being retained for commuter/dart.

So the bus is good enough for people living Dublin but clearly not for people living outside Dublin who need to be provided with modern rail based options even if only a tiny fraction of them actually want or need it?

A few km? The average person living in Dublin spends an hour commuting, twice the European average and the fourth worst city in Europe and 15 minutes higher than the rest of the country as a whole despite much higher commuting distances travelled outside of Dublin. This translates into a week of human life wasted per year per Dublin commuter.

Fixing public transport in Dublin benefits the whole country. Having lived for a few years in the country with the highest rail usage in the world has taught me that having decent public transport within cities is the key to making intercity rail (and other longer distance public transport) viable. Having extensive metro and heavy rail options from the likes of Connolly to get you around Dublin quickly and comfortably would have a much bigger impact on making the Enterprise service attractive than shaving 20 minutes off the journey but then expecting arrivals to use taxis, slow buses or walk long distances in often poor weather to actually get to their destination within the city.

Tbf folk aren't on intercity coaches twice a day, 5 days a week. You can't begin the discussion talking about intercity coaches and then pivot to Dublin Bus, they are a different product and serve fundamentally very different objectives.

It slows down both services.  Intercity/commuter train can't begin to enter the section until the Dart is in the loop. And the Dart can't leave the loop until the Intercity/commuter has left the section.

This doesn't make much sense to me. An Intercity/commuter train certainly can't enter the section with a DART if there is no loop, so even if the intercity/commuter doesn't use the loop, it won't be any slower. And if it can use the loop, it can move forward and gain 5 minutes.

The case for the leaving DART being slowed sounds more plausible but given that DARTs stop for about a minute? That gives an intercity/commuter travelling at a leisurely 60km/hour about 1km clearance to get past.

They're all over Switzerland and seem to work pretty well.

Isn't the envisaged scenario triple track with additional passing loops? So Dart has a dedicated pair of lines, then one line with passing loops for long distance? Even a worst case scenario 5 minute stop wouldn't be too significant on a 2hour journey.

Well that's not what you claimed first which is that the mere presence of passing tracks at stations slows down both services? A completely illogical claim and one completely at odds with what I've experienced at what was my local station in Zurich.

Even if you were to eventually 4-track it - and I'm not at all against the idea, I just think it shouldn't be anywhere near a priority - having a bunch of stations on the alignment which have already been upgraded with passing tracks would simplify the process of fully 4-tracking the route considerably.

You have to add the passing tracks at each station as part of 4-tracking anyway, so why is there so much push back against then idea of adding them in advance of full 4-tracking?

This is how the Kildare route 4-tracking project happened by the way. Stations had 4 platforms/tracks before the extra tracks were added to the alignment.

You get an immediate benefit (5 minute journey time reduction per station) instead of waiting decades for funding for a mega-project, and then years of disruption (I doubt it could be done without completely shutting the entire alignment for significant periods of time) before a single passenger sees any benefit at all.

And it's exactly the sort of solution they go for in Switzerland because they don't have the neuvea riche attitude we have in Ireland when it comes to rail - they're extremely practical and happy to continuously work on relatively modest incremental improvements year after year - carefully appraised in terms of value for cost. The Swiss network has significant sections of single track, stations on curves, level crossings and all sorts of surprisingly inefficient and obsolete pieces of infrastructure so it's not like every alignment/route is modern spec. They also do the occasional mega projects - like interconnectors - but it's not the once-every-10-years new tunnel/station/etc. that makes the system great.

One piece of advice would be find one of the tourist special rail passes online on the sbb.com before heading over if planning on a non-local rail trip. If you buy on the day without what is called a Halbtax (only available to residents), you’ll effectively pay twice the price. If you thought UK rail tickets were expensive…

I do think 4 tracking the northern line is well worth it, even if it may seem slightly trivial at the moment. The DART definitely needs 2 tracks all to itself with the planned amount of service that will be using it, and this leaves the question of 1 or 2 extra tracks for intercity services.

I firmly believe it should be an extra 2 if at all possible, as once Enterprise Services are made hourly as of this Autumn, there will inevitably be conflict of paths around this area, along with the hourly Drogheda Commuters and eventually hourly Derry trains via the (hopefully reopened) Derry Road. And as well as that (not in the know, but I’m presuming) it would be much harder to signal a single bi-directional line for mainline high speed services into Dublin than to just add the 4th track and have two single-directional lines. Not sure though but that's how it seems to me. 3 tracks might just be easier space wise however.

In terms of actually going about it, if you look at the alignment on Google Earth, the vast majority of the line from Connolly to Malahide has space to expand to 4 tracks. Most of the time between Connolly and Howth Jnct it’s in a cutting or on an embankment. The great thing about these is that if you replace a sloped embankment with a vertical retaining wall, you lose no space on the surface as far as back gardens are concerned but gain lots of space at track level and I believe most of the spacing issues for the 4 tracking can be overcome by this method. The section between Clontarf Road and the Royal Canal poses the most difficulties. An extra two spans will need to be added to the Clontarf Road, the direct line to the East Wall and the Tolka but beyond that there are only 5 small overbridges over minor roads that will need to be reconstructed.

In terms of stations, Clontarf Rd is an easy fix as it’s elevated which means a ‘basement level’ booking office and underpass to connect the platforms would be easy to reconfigure the station around 4 tracks. Killester can be relocated south to the Collins Avenue overbridge, which while being closer to Killester town centre, also has more space than the current hemmed in station for a wider 4 track station. The story is the same at Raheney where the station could be relocated south by 100 metres to an area where there is much more space for an inevitably wider 4 track station (access from the Howth Road behind the church car park).

Harmonstown is a bit more difficult but could just be kept in the same location but with the platforms extending northward from the station rather than south as there is slightly more space here. Unfortunately there is no space for expansion at Kilbarrack without the removal of the platforms however due to its proximity to Howth Jnct, (200 metres) a simple renaming to Kilbarrack and Donaghmede and the addition of a southern access to the station off the Kilbarrack Road could remedy this slightly. Either a total reconstruction of Howth Jnct or the demolition of a few houses will be needed to get the 4 tracks through it. From there to Malahide though there is little work needed to be done to fit the 4 tracks. Portmarmock could be moved ever so slightly south again where there is more space. Makahde will be similarly trick to do and while it could also be moved south to be off Bridgefield Park, I’m still not sure about what to do here.

Now I have not done any measuring or surveying these are my observations based on Google Earth alone so a lot may be off and I’m open to correction on some of the things I may have said were possible. But while it might be tricky and upset some people I think it’s worth investigating the possibility of a 4th track, at least for most of the route. Whether it’s 3 or 4 tracks though, capacity enhancements are desperately needed on the Northern Line if the DART wants to increase in capacity and the Enterprise wants to in any way feel like a premier and competitive service