Navan Rail Line

PlatformNine

https://www.boards.ie/discussion/comment/123471315#Comment_123471315

I wonder does it just help spread out the cost? DMU's first, BEMU 10 years later, OHLE and conversion to EMU 10 years after that. I have no idea if that makes financial sense, but perhaps just a way to avoid too high upfront cost and sticker shock.

to clarify, from my understanding they never were going to install OHLE electrification, BEMUs were the solution to electrification. That is what I always found so odd. I might have completely misunderstood that, but I believe the timeline was: open-2045 use DMU stock, 2045-2060 use D+ BEMU stock, and post 2060 replace D+ BEMU stock with other BEMUs.

We know for Drogheda the plan is to switch over to EMUs and (as far as I am know) we have no idea what their final plan for Wicklow town is. So electrification of the Navan line may depend on final frequency for Navan which we should find out next year, and whether or not they plan to Electrify Greystones-Wicklow which I am not sure when or if we will find that out.

Totally crayoning by my part, but I could see it as a simple extension of the ML line North of Swords. No need to cross ML line then, just extend from the end of it. You could also have an extension East towards the Northern line. I think there is lots of development potential in that area between Ashbourne and North Swords.

The Swords-Ashbourne metro is an interesting option. I dont see why it wouldn't work, the important part would be getting into the town centre (if they choose to do that of course) and it would allow TII/NTA to focus more resources on other less developed areas.

A complete side tangent but it reminds me of a thought I had that TII could consider upgrading the R125 to a national secondary road to allow a corridor between the Dunshaughlin station on the Navan line and the ML Estuary P&R. But I would much rather see that as a rail corridor considering the sizable population that lives on it.

My main consideration for Ashbourne having a better line into dublin is that by the time any line is complete, it would have likely broken 20K people, and potentially even be reaching towards 25K if it keeps growing at the same rate as it has been. I think it would be large enough to justify a proper line between it and Dublin, without the line it could be a repeat of Navan in a decade or two.

bk

https://www.boards.ie/discussion/comment/123471662#Comment_123471662

I really should go look at the report, I'm just working off general principles here!

I think long term whether you stay BEMU or switch to OHLE depends on frequency. Drogheda at 6 DART+ PHPD + new electric Enterprise using the line hourly and possibly an electric Dundalk commuter, makes OHLE easily justified.

Wicklow I suspect will stay BEMU, as at best can only handle a train every 20 minutes.

Navan, if every 20 minutes or even 15 minutes might be borderline. By 2060 I wouldn't be surprised if batteries cost 1/10th of what they do now, given how fast prices are dropping, making staying BEMU on even a higher frequency line the better economic choice.

BTW One point on Drogheda, it can only go to 6 DART+ TPHPD by going EMU, there are limits with space for charging at Drogheda station that limit BEMU's to only 4 or 5 TPHPD. So it has that extra pressure to go EMU, a pressure that might not exist on a lower frequency line.

Just to be clear, I'm not saying any of the above with certainty. More just a feeling relating to how fast battery tech is coming along and how quick battery costs are dropping. In the end it is mostly an accounting decision, big upfront OHLE capital cost, versus extra cost of replacing batteries every 15 years (though batteries will cost much less every 15).

In the end I think the most important thing is just get the line open ASAP. Get trains running on it. Upgrades to BEMU/OHLE can be worked out later.

My main consideration for Ashbourne having a better line into dublin is that by the time any line is complete, it would have likely broken 20K people, and potentially even be reaching towards 25K if it keeps growing at the same rate as it has been. I think it would be large enough to justify a proper line between it and Dublin, without the line it could be a repeat of Navan in a decade or two.

Do you mean it's completely own line to Dublin. I think that would be unlikely. Most likely either a spur off the Navan line or Metrolink. Surprisingly Metrolink would be shorter distance then via Navan.

I suppose you could extend Finlgas Luas to it. But it feels a bit too far for Luas. It would be twice the distance of a Lucan Luas. 20km on a Luas would be rough. Though perhaps they could use the more commuter like trams with higher speeds like the Dualis.

Thing is going via Swords and Metrolink is only 6km longer. And while longer, I wonder if the journey time would be faster due to it being a Metro, full segregation, higher speeds, tunnel in Dublin City, etc.

Other advantage is that it would be an easy trip to the Airport (and Swords). I suspect that a lot of people who live in Ashbourne work at the Airport. Also it might help Swords develop as a sort of North Dublin hub. Could Swords grow big enough to get it's own University? Easily accessible from both Dublin City and Ashbourne.

I know, all just crayoning by me. I just feel this area of North Dublin/Meath has so much exponential for development.

PlatformNine

https://www.boards.ie/discussion/comment/123471827#Comment_123471827

I suppose I am just a bit skeptical of how well BEMUs could replace EMUs long term even if prices dropped. But maybe I shouldn't be as that is data we won't have until Drogheda BEMUs have seen service, and potentially not until the first battery replacements for the fleet.

My main concern is the number of units a continous service frequency could require.

Do you mean it's completely own line to Dublin. I think that would be unlikely. Most likely either a spur off the Navan line or Metrolink. Surprisingly Metrolink would be shorter distance then via Navan.

My thought was that it would be the northern terminus of the next metro line. However realistically I imagine by the time a line like that could be reaching Ashbourne it would be far overdue, as it is not likely to be the next metro line. The next best thing, and in the real world probably the actual best option is the Swords-Ashbourne extension.

KrisW1001

Ashbourne is probably too far away, and too isolated (the Dublin Airport exclusion zone lies between it and M50) for Metro. However, it could instead be served by DART services running on the Clongriffin-Drogheda link proposed by the All-Ireland Rail Review.

For the Navan line itself, I would like to see a routing like this to serve Ratoath and Dunshaughlin:

This is around 3km longer than following the existing alignment. and involves more difficult terrain, but it would capture far more users.

bk

https://www.boards.ie/discussion/comment/123474504#Comment_123474504

However, it could instead be served by DART services running on the Clongriffin-Drogheda link proposed by the All-Ireland Rail Review.

The AIRR report says that the Clongriffin-Drogheda should follow the M1 and as a result be significantly shorter and faster then the existing DART line. If you routed it over to Ashbourne it would lose those advantages. Plus I believe the idea is for this line to be the intercity line, to take the Enterprise and Dundalk commuters, while the DARTs stay on the coastal line.

I suppose you could spur off it and head to Ashbourne, but I don't really see much advantage of that versus spurring off Metrolink.

https://www.boards.ie/discussion/comment/123474319#Comment_123474319

I suppose I am just a bit skeptical of how well BEMUs could replace EMUs long term even if prices dropped. But maybe I shouldn't be as that is data we won't have until Drogheda BEMUs have seen service, and potentially not until the first battery replacements for the fleet.

It is totally fair to be sceptical. We will all be watching the performance of the new BEMU's with great interest. In terms of Navan, it is so far in the future, I feel there is plenty of time for IR to gain experience of operating them to Drogheda and plenty of time to see how battery costs go in the market.

BTW To just give you a sense how crazy the battery market has been over the last two years, over the last two years average battery pack prices dropped from $153 per KWh in 2022 to $110 per KWh by end of 2024. That is like a 25% drop in just two years!

Analysts last year were predicting $60 per KWh by 2030, but there are already reports out of China of it hitting that price this year! Really extraordinary stuff. Of course past performance is no indication of future performance.

Pete_Cavan

https://www.boards.ie/discussion/comment/123474504#Comment_123474504

I think it would be insane to try follow the old alignment, most of it doesn't exist anymore and it serves no people. A rail line would have to serve Dunshaughlin at least, ideally Ratoath too. Whatever route is selected, it would almost certainly continue along the old alignment along the southern side of the M3 for another 2km. Then it could cross the M3 where the Southern Toll Plaza is now (assuming toll barriers get replaced by ANPR in the not distant future so plenty of space to build).

If you loop round the northern side of Dunshaughlin, why go to the cost of crossing the M3 again? Just hug the north eastern edge of the M3 until it curves at Lismullen. That would be ~8km without dissecting any farms and no buildings immediately adjacent to the motorway. You also don't have any motorway junctions on that stretch and only three minor over bridges to deal with. About as easy a build as you could get.

Rather than following the M3 curve at Lismullen, the rail line could continue north west. Then ~9km to Navan which unfortunately would come with landowner issues. Loop around the northeastern edge of Navan (where all the new development is happening) and join the Navan - Drogheda line into the centre of Navan and even out the other side. You could have three or four stations in Navan which is what is needed to get the passengers required to justify the cost.

Following the old alignment will cost as much (if not more) and be more contentious (it's been farm land for 50 years), it has no advantages.

Round Cable

https://www.boards.ie/discussion/comment/123474808#Comment_123474808

I would be more confident on the future of BEMUs. The cost of installing and maintaining the overhead electrification system is very expensive, and with battery prices going down and densities getting better, it may make more sense to adapt a system like Siemens Rail Charging Converters.

This system sees the installation of discontinuous overhead electrification around train stations and other strategic points, it connects at 11kV to the local grid rather than the high voltage system. They claim significant cost savings and an install time of 18 months vs 7 years for a traditional OHLE installation.

https://news.siemens.co.uk/news/siemens-british-battery-trains-set-to-save-gbp-3-5bn-and-consign-diesel-trains-to-history