Navan Rail Line

Definitely better to start from scratch, the entire old alignment would have to be CPOed anyway. I don't see any cons but it would allow the major pros of actually serving people before Navan (one of not two reasonably large towns with established commuter populations). Most of the Navan expansion will be around the Johnstown/Kentstown Road area so a station could be added there before linking into the existing rail line into Navan.

Last I heard the plan was to have a Navan Central station just before the point where the line joins the existing Drogheda - Kells line, so a Johnstown station would be a nice addition there too, but was there also talk of reinstating a stub of the Kingscourt branch and having a Navan North station beside some sort of a new TOD that was planned with big housing numbers…?

Apart from that Boyne bridge, there aren't any significant structures. An overgrown road bridge near Batterstown that may need to be rebuilt but you'd be passing through gardens either side to go under the bridge.

Against that, you have to cross the M3. I'm sure someone will mention some provision for an underpass but getting enough clearance under there would require major works with tracks having to start descending a couple of hundred metres away either side. There are a good few houses on either side and the position of the underpass (whatever was actually done) limits flexibility in the alignment.

On the old alignment, you'd have to cross the M3 J8 link road which would be a wide crossing at significant height, therefore very expressive to build. South of there at Cannistown, much of the alignment has been built on.

On the old alignment, you'd only get into Navan as far as the R161, maybe cross it with a Level Crossing but no further. That would not be easily accessible for most of the population of Navan.

You say yourself that deviation from the old alignment is needed at Kilmessan and Drumree anyway. All that the old alignment offers are some stretches of ditch where trains once ran (and as much is not even ditch, it's through fields). It doesn't offer any benefits in terms of CPOs, constructability and serves practically no people.

It might not make too much of difference for the people of Dunshaughlin, however it could be much better for the other towns in the area. Which I hate to say, but its more important to better serve the towns closer to Dublin than it is to serve Trim. The previously proposed station would only be a few minutes away from Ratoath, and about 15 minutes away from Ashbourne. It's not quite as benificial for Ashbourne as it is for Ratoath as by this point Luas Finglas would be complete, however depending on where someones final destination is, many might still prefer a DART.

A station closer to Dunshaughlin could also encourage at least some people to walk or cycle, however footpaths would need to be extended to the staiton, and ideally so would a cycle lane. However even only a few people using active travel it is better than the Dumree station practically requring everyone to drive or take a bus.

If serving Trim really is a concern and the M3 Parkway isn't sufficient as a P&R option, there is still better ways to serve Trim than a Dumree P&R. If they have to deviate around Kilmessan like you say, a station west of Kilmessan could be better for Trim residents.

They should be future proofing the rail line to Navan by putting it between Rathoath and Dunshuaglin as long term with housing in both towns will be expanding so much they will meet and you then would have a railway in the middle for public transport.

Then with navan have it on the east side of johnstown with a station as the same will happen with housing spreading east.

There will be very little devleopment on the westside of Navan compared to the East side. If you put a train station on the edge of eastern johnstown you will be in the center of a major urban area in 20 years.

I don't believe the plan was ever to terminate with Navan Central but to continue through Navan with the old alignment and the Kingscourt line, and additionally build Navan North station were the greenway currently starts.

I do see now that there are definitely alignments that would have a better catchment, but its not ideal to have a long winding alignment through Navan. A rail alignment could be routed east of Navan and that would serve denser areas, or they could use the existing Navan and Kingscourt line. Bending back to run on the Navan-Drogheda line really doesn't do much good, it would massively increase catchment but it would significantly slow down services pushing people back into their cars.

it has 2-3bn in the article itself. That would include Contingency of 50%, assumptions around inflation, and likely all the taxes incl. VAT that the government get directly back.

It won't bode well for the scheme if that was the actual cost to the exchequer.

How are the costs possibly that high? For comparison:

1. The 34km N5 Ballaghaderreen to Scramoge road upgrade (entirely new road on green field) is costed at 450m. That's almost 6x lower cost per km
2. Foynes line upgrade and reopening is expected to cost 105m for 42km. This will allow freight to operate initially. Adding passenger services will cost more, but the majority of infrastructure works will be completed, so isn't going to cost another 2.9billion.

Obviously no 2 sites are comparable, but I can't possibly see any justification for such an insane cost. It's a surface rail line which will utilize an existing, disused, alignment for a significant chunk of the 40km.

I agree that €3bn sounds very high (a rule of thumb I’ve seen is that a greenfield two-track electrified railway costs about 2~3x of the price of a motorway per km), but that disused alignment needs to be completely rebuilt for most of its length - you’re really only saving on land acquisition costs.

Additional costs arise from electrification (say €2m per km, but could also be less than that) and from having to elevate the railway over M3 (there's no routing that doesn't involve crossing this road at least once).

A railway is a machine for guiding trains; a motorway is a long flat surface on which drivers guide themselves. Railways are narrower than motorways, but they have thousands of parts (sleepers and clips) that need to be precisely installed, plus points, communications and signalling that roads don’t need. Railways also need to be able to accommodate heavier axle loads than motorways - 20 tonnes per axle, compared with about 10 for a motorway.

Using that old alignment would mean CPOing properties and two Level Crossings (plus another at Commons Road) to get to the Kingscourt line. Maybe that's not a huge issue but it's not ideal either.

And what I suggested wouldn't be "a long winding alignment through Navan". If the rail line is already east of the M3 having served Dunshaughlin, it's a fairly straightforward route making use of the existing alignments through Navan. I really don't see it slowing down services, in the won itself the line would be grade separated as far as the old station location. The alignment route would have many level crossings from the Bective area and into Navan itself.

Given much of the population of Navan lives east of the Boyne, I don't see how any potential station on the old alignment would adequately serve them. There are no suitable routes for most people to get from their home to a station there. That is more likely to push people to cars.

Yes, as far as I know, CIÉ don't own the land anymore. It was only for some of the later abandonments that they retained the land.

It costs €2.5 million per carriage for the new DART EMU stock, so let's say €150 million for 12 5-car trains.

It's really hard to add this all up to three billion...