DART+ (DART Expansion)

That’s capacity though. On the initial CBA it seems really vague and doesn’t even model the impact of MetroLink (they say this could cannibalise passengers but I can’t see how it does that). They say 25-30m more boardings by 2043. That would (I guess) bring it to 55m-60m for those particular routes. It seems hyper conservative, almost like it is a box tick.

The existing DART operates well below its capacity. At peak time 8am it appears to carry a little over 10k between both directions. Capacity is around 20k (10 tphpd- I know some DARTs are shorter at that hour but I believe each can hold 1,200)?

I wouldn’t expect 100% occupancy but that does appear to tally with the experience vs. the Luas where it is quickly wedged. There’s so much slack in the existing DART to grow into and new developments / transport connections will do it.

Like if the MetroLink wasn’t modelled it’s a bit mad, if you take the MetroLink Airport integration at Tara alone I’d think that will drive at least 1 million passengers to DART Coastal services per annum. This would be almost exclusively from the southside and would be by basically taking out the theoretical capacity of the 702 Aircoach route.

75m does seem really doable to me, even sense checking that vs. the Copenhagen S Bahn it follows.

Ha you’ve just repeated my post!

I had thought they had done detailed analysis on D+ and not needing the tunnel anymore. Seems to be more to me on the capacity side. I think the shortcomings at Heuston will be apparent after about a year. People will ask why so few trains continue to Connolly / Spencer Dock and also why they can’t get more central.

DCC are proposing to build 2 story houses on Broombridge industrial estate, one of the most well serviced sites in the country at least in terms of transport so I would expect a lot of the available land to be wasted in such a manner.

Tbh I don’t know on the D+ W and SW lines. It’s hard to gauge when the increased services haven’t been put on yet.

I do know on the coastal line (s) that there is a fair bit of extra demand that can come on stream in the next few years and a lot of people who live near it will start to use it more once they can get to the likes of St Stephen’s Green quicker.

Here’s what the business case document for DART+ proposed. This shows line capacities, and with some small restrictions, any number of the trains entering a junction from the west can come out on either of the paths to the east, so, for example of the 7 Southwest + 12 West = 19 trains passing into Glasnevin, 7 will go to Docklands direct, 4 will go to the docklands via Drumcondra, and the rest go through Connolly towards Bray. How many of those trains have come from West or Southwest will depend on demand.

As for how the Loop Line can cope, the extra capacity on existing lines comes from two things: first, preventing Diesel trains slowing down Electric ones, and second, adopting newer, more modern signalling. An all-electric line can operate with trains much closer together than one using a mix of diesel and electric as at present, as diesel trains take much longer to accelerate and so cannot move between the closely-spaced stations in Dublin as quickly as an electric train. I also expect that regional and inter-city services will be removed from the loop line so that it becomes an electric-only line.

The second factor is the new line signalling: ETCS (European Train Control System) allows trains to run at higher frequencies without compromising safety. The coastal line has already been re-signalled, and the signalling will be upgraded on the other lines as part of the DART+ programmes. However, only the new DART trains can take advantage of this signalling improvement. But by the time the DART+ upgrade is done, the original DART trains will have been retired and replaced with the new stock, and I suspect the newer DART trains from the early 2000s are likely to have been refurbished and updated to use the new signalling too, so there will be a small but significant increase in capacity from that.

The practical limit for a modern two-track electric railway is about 30 trains per hour per direction, but time needed for boarding and alighting at stations reduces this frequency unless stations can handle the volumes on board.

I'm sure I read somewhere (can't remember where) that a lot of responses to the public consultation on Broombridge objected to the low density. Maybe is was a timid approach by the council that will be revisited in light of such a response.

Deciding what to do on the Rosslare line (stopping a number of them at Wicklow or Bray) will tell a lot coming south from the Loop Line. Are there any previous proposals to add a platform to Tara or Pearse (DART Underground excepted). I don’t see the necessity for the Rosslare line to get to Connolly myself. Getting to the city centre in itself is reasonable, particularly with onward connection provided like DART Underground provided and which MetroLink provides. It’s unfortunate that you have that capacity at Grand Canal Dock but that’s too far from the core & provides only DART connection but doesn’t provide onwards connection that Tara will to St Stephen’s Green or O’Connell Street that ML will.

I have wondered with the Ronan plan for Tara Street Station mothballed / challenged whether Irish Rail could revisit the use of that site. I’ve been curious to know whether IR knew about the MetroLink’s Tara potential integration when they went to market, the dates to me suggest not. It’s too tight in itself I guess but Ashford House getting demolished for ML and a plaza due there after, surely there is scope there? They can still monetise the air rights and provide for public space but it seems to be a bit of a wasted opportunity to me considering the connections Tara will provide.

The Bray / Wicklow proposal I know helps on both fronts (D+ Coastal South Capacity and the Loop Line) but it is still a fairly inelegant way to do it.

You’re not wrong there. The most bang for our buck service wise is probably still twin tracking to Greystones (which will cost a fortune) and halting Rosslare trains before they reach Dublin. I do wonder on Tara though, whilst the space is there.

With only 5/6 services a day between Wexford and Dublin, an hourly Rosslare/Wexford "shuttle" to GreyStones would be a vast improvement on what is there, and most likley quicker.

And a few passing loops after Bray might allow them to continue to Dublin. Might also allow some peak time express services from GreyStones/Bray/Dún Laoghaire into town.

Refuelling, cleaning & maintenance would need to be taken into account also, potentially move this to Wexford for services on those lines? A set requiring maintenance or a refuel heads to Connolly off-peak/late at night, etc. Not sure how frequently the ICRs need to get refueled, mind you.

I just can’t see the AIRR plans for the Wexford line working in reality.

Trains would have to first crawl along the quays travelling away from Dublin, before reversing at Rosslare Strand and travel along an railway line that would need significant investment to not only reopen it, but to upgrade it to a sufficient standard for intercity services.

All of that and the train has only gotten as far as Waterford.

Even if this somehow works for Wexford, it does nothing for the other sizeable and growing towns like Enniscorthy, Gorey and Arklow along the line.

Wexford=Dublin via Waterford is nuts. Its about 40 miles longer than the DSE route for a start. Waterford-Heuston is about 2h15m, and even with a 2-hour speeded up journey, that would make the trip form Wexfprd about 2h40m. The present service may be slow,but replacing it with something even slower ia juat plain nuts.