Can Anyone Tell Me Why a Heavy Rail Link to Dublin Airport Can Not be Built in the Short Term?

Bit late to the party, my apologies, but the way that I would see a heavy rail link to the airport working out the best way possible would be in connection with DART Underground. If DARTs from the Heuston line entered the proposed tunnels at Inchicore with an underground station at Heuston, they would emerge at the Docklands, and join with the (quad tracked at this stage… hopefully) Northern Line and run non stop to Clongriffin where it would stop to connect with other DART services and maybe a few Enterprises or stopping trains from the North before branching left through to the airport. Heavy Rail services can then leave the airport for anywhere in the country with maximum 1 change theoretically. This is in an ideal world however, and unfortunately in terms of railways, our country is far from that…

Something that I think would work is to have at least every second intercity service into Heuston from each major destination call at Hazelhatch and Celbridge for an interchange with DART+ SW services to Glasnevin where a Metro and airport link could be made. This would be possible with signalling too as the DART+ programme aims to increase services on that line from 12 trains per hour to 36! And to facilitate a stop at Hazelhatch without adding to journey times, stopping at Kildare and Newbridge could be cut out for most intercity services and taken up by the stopping Portlaoise services instead. This, I feel would be a bit of joined up thinking airport transport wise.

The second part of OisinCooke's proposal is going to be the best way to get people country wide to the airport:

Northern Line, Metro extension at Lusk

Southern Line, Tara Metro

Sligo Line, Glasnevin Metro

Heuston Line is always going to be the most challenging to connect. With just Metrolink it's going to be two transfers (to Dart SW, then Glasnevin metro). But given the frequency of those two modes it shouldn't be a major problem (at least not major enough to justify a full heavy rail link from Hazelhatch round to Clongriffin by itself).

The way I see it, the optimal method for that line would be, ICs stop at Park West (Or Ballyfermot, and build Ballyfermot station sealed in with platform screen doors so its pleasant to sit and wait at.) before pulling into Heuston to allow Dart transfer (Rather than Hazelhatch so they can 'skip the queue') and ICs will be slowing on the Heuston approach then anyway.

The longer term "one transfer" solution will be Dart Underground/Dart+ Tunnel getting built with a Tara/SG West station for metro to the airport.

I think a heavy rail spur around Dublin would have to stand up on its operational benefits to the network as a whole rather than its ability to funnel people to the airport from down country. Especially given that we should be aiming to reduce air transit in favour of lower emissions options.

Definitely Metrolink up to Donabate would be great and would really open up a lot of that land in north Dublin for development as well as providing a connection from the North to the airport via Enterprises stopping there. I do think there would be worth in the the Clongriffin link too though as it would be a direct heavy rail link to the airport from the southwest commuter and (by DART Underground) all the lines out of Heuston but as you say it’s a case of cost vs benefit…

Yes actually I completely agree with this, it does make a lot more sense to do Parkwest, or even Ballyfermot (although the proposed site for this at the Kylemore Road Bridge doesn’t seem to leave a lot of space for 4 let alone an extra 5th platform…) I was just thinking Hazelhatch because it’d give access to all the stations on DART+ SW but your point about the trains slowing down anyway is very well made. And in fact there’s more space around Parkwest for a 5th or even 6th platform to give all Intercity services ample space and time to stop and interconnect with the DART’s. And yes ideally DART Underground will make the airport a one-change trip from absolutely any major city in the country which is great, regardless of whether the DARTs themselves follow through to the airport or whether it’s via a Metrolink connection in the city, I just hope it happens soon…!

A lot of thought really needs to be put into making Dublin a truly interconnected city transport wise, and this is before we even start talking about other light rail but I think that if the above few points are implemented in some way shape or form, it’d do us all well

My reasoning for dropping Kildare and Newbridge in favour of Hazelhatch or Parkwest was that if all the ICs stopped at Parkwest or Hazelhatch, then that would provide the junction between all the lines but actually you’re right Kildare is the probably still the most ideal as if you’re going to Parkwest, you may as well just change in Dublin…

To get back very bluntly to the actual topic, it depends on your definition of 'short term'

If 'short term' means 'between now and when the metrolink is built' then it won't be possible because the planning process for such a link will take longer than the remaining time on Metrolink (barring some huge disaster of a change which would probably also affect any heavy rail planning anyway)

If it means 'after Metrolink exists', the the answer would be 'Because the Metrolink exists and does a better job of what you'd want the heavy rail to do, i.e. transport passengers to Dublin Area for onward travel. There isnt any chance of air to rail freight as far as I can see so no justification for it there, and the 'one change' option works for a majority of potential rail options, where your biggest risk is a long wait for the Intercity, which you'd have anyway with one change if you got the heavy rail spur from Airport to Connolly

Finglas -> Broadstone could also be converted to Metro Grade right? If it were so desired, depending on how they did the Broombridge -> Finglas section

What a load of nonsense. The Dart Spur project has been examined by DCC and Fingal and by external consultants, all of which has indicated it has pretty poor value for money. Particularly given it can only functionally exist as a shuttle service to Clongriffen, and the existing constraints of the dual track on the Northern Line.

Indeed. Spending in the Billions for 3km of new track, versus the Metrolink project which serves Swords and beyond is indeed very poor value for money. If you built the spur and didn't expand it to 4 tracks from connolly, and do the various improvements you would need to do to make it worth it, from the city centre it would be faster to take a bus to the airport than doing 2/3 changes on a Dart service.

I wouldn't be so sure.

Back in the day, I had myself convinced that electric cars could never practically replace internal combustion vehicles (power density, weight and all that) nor that batteries could have any role in utility scale storage (way too expensive).

Both these predictions turned out to be spectacularly wrong. I had underestimated the unstoppable power of mass production - in this case that of batteries - leading to a 97% price decline in 30 years (and seemingly continuing - CATL or BYD recently announced a 40% price cut for some of their battery lines later this year) and constantly improving chemistries. EV range is doubling every 7 years which means they are constantly eating into applications currently only possible with ICE.

One trump card for electric is that the cost of "fuelling" an EV is a fraction of that of buying fuel for ICE vehicle. And the aviation industry is fixated with fuel costs - so there is absolutely no way I would bet against electric aviation being a thing within 10 or 15 years particularly for shorter flights - say less than 90 minutes.

Like with cars, there will be niche applications where the tech will not initially work (medium and long haul), but it's a mistake to think that just because the technology cannot do 100% of what a previous technology could do, it won't succeed. The fact that horses can do lots of things that cars can do didn't stop Henry Ford.

Small electric aircraft are already available to purchase.

Up to 3 or 4 years ago, the consensus was electric could scale at most to a 20 passenger aircraft with a range of about 200 miles - anything beyond would require hydrogen, biofuels or syngas. Now there are companies working on 90 passenger/500 mile electric aircraft - admittedly at an early stage of development - but it shows their engineers think it's feasible.

And of course, all these companies working on such aircraft realise that weight is their biggest issue. I saw one calculation that with current tech, it would take 35T of batteries to power a fully loaded 737 (about 70T).

Sounds hopeless until you appreciate the power of exponential growth - both in terms of affordability and performance.

Battery performance, along the most important metrics such as power/weight ratio, has improved more slowly but still exponentially - roughly 8% a year over the last 20 years or so. If this trend continues, then the 35T of batteries required to power a 737 will fall to 17.5T in 7 years time, 9T in 14 years time, 4.5T in 21 years, etc. You can see where this is going.

In terms of costs (the bottom line for commercial aviation), battery prices have decreased exponentially over the last 3 decades - now costing 3% of what they did since li-ion started to be mass produced - representing nearly 14% price decrease year-after-year for 30 years. I see no obvious reason why this trend/progress would suddenly stop at this point in history.

You've just described Metrolink, no?