DART+ (DART Expansion)

Noone has really mentioned that Northern line is included in the plans for Spencer Dock

4.7.3.1 Alignment
Spencer Dock Station requires the construction of four tracks and two island platforms. The design of these
tracks includes the following key features:
• Four platform tracks accessible from the MGWR line.
• Two platform tracks accessible from the GSWR line (Platform 3 and 4).
• Two platform tracks will be accessible from the Northern line (Platform 3 and 4).

Yeah that's true, it's been mentioned. However the proposed plan has a single alignment connection between Ossary Road and Spencer Dock, into platforms 3 and 4 of Spencer Dock, so it's far from ideal.

Directing trains from the Northern line into Spencer Dock will require trains to wait for a signal on the Northern Line blocking other trains. That section of the Northern Line before it crosses the Tolka towards Clontarf is only dual track right now.

Sorry, but which Docklands trains are blocked when there’s an up train at North Strand Junction? I’m not really understanding which Docklands train would be affected here.

That's all well and good, but it's not ideal to create another conflict point at a junction that is already congested. I can't see Northern Darts heading into Spencer Dock based on the current proposal.

But isn't that why Maynooth line is the first line to be electrified ? Because it's budget and scope includes the Connolly area enhancements including the signalling aspect?

Any signalling changes can be done without needing a RO, and can be done at any time too. Same goes for crossovers and other small works.

There will of course still be bottlenecks after DART+, but the sensible thing to do is to run the services, find and fix the issues that arise due to electrification, see where the problems actually end up, and address those factors, rather than adding complexity and cost to fixing something that you think might cause issues after the project is done. There's a famous saying from computing that applies to all systems engineering: Premature optimisation is the root of all evil.

Changing from diesel to electric trains in these lines completely changes their timing. That plus the new, more flexible signalling may make those bottlenecks less of a problem than they are now.

Just to be clear it's only my opinion that an RO isn't needed; I've no expertise or inside knowledge here.

However, those in the know have mentioned that ETCS signalling upgrades have been progressing already, and there's been no RO applications needed for that work.

As far as I understand it, an RO is the direct equivalent of a planning apication and so is only needed if structures are being erected, removed or materially changed. Erecting a couple of hundred cable gantries and building new transformers, stations, bridges and depots certainly needs permission, but my impression is that operational matters like moving signals around would not be significant enough to need ROs.

Something like this would be very doable I think. A two-level station on the junction just over ‘the dip’ has well enough space for two 168 metre platforms on all four tracks, (shown in purple) requiring only the shortening of the washdown siding on the northern line, which can just be shortened and accessed on a crossover after the station (shown in red). Access from Ossory Rd with space for a small car/bus park is also doable but I suspect it will mostly be an interchange station. Plenty of space also for a lift and over/underpass to connect all 4 platforms. I suspect it could be very basically and easily achieved and for a reasonable price even… dare I say!

You can't really shorten the wash road. It's only just long enough as it is. At peak times, you wouldn't be able to clear platforms for incoming trains.

Can it be moved ?

I guess nothing will happen until a report, or several, has been prepared on the 4-tracking element. In the absence of DU (in one form or another) for the foreseeable, an interchange at North Strand Junction will be badly needed. Capacity on the current and proposed Dart lines will be severely hobbled by constraints at this junction.

For most of the route past Broombridge, it has the canal on one side, but a lot of the line past Pelletstown there is green space the opposite side to the Canal.