DART+ (DART Expansion)

Fair enough, my thinking was that a short train was better than no train, and sending half length trains could serve as a interm solution if platform extensions aren't complete by the time the line is "DART capable." I am not sure how long the extensions could take. That way they could at least begin Wicklow services even if it isn't at full capacity. Or if they are running half length sets it could only be Wicklow-Connolly so as to not take away northern line capacity

In terms of the new fleet deliveries, was it just the one driving carriage delivered last Friday? If so, is there any indication as to when the 4 other carriages to make up a full consist will be delivered?

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To my knowledge, most/all of the bridges along the Dart+ West line are protected structures and will not be demolished.

The bridge at Castleknock station is not protected and was originally to be demolished and replaced but that was not popular and the final design involves raising it to allow for the OH wires.

Can't speak to other lines

the detail is still relevant. charging infrastructure is planned at Wicklow but unlikely they'd have a battery given the level of service would be much lower than at Drogheda.

Max number of battery trains you could get to Wicklow is likely to be 1 per hour. Getting two trains (three with the DMU) down and back in a given hour, while allowing for charging and the passing on the single line section between bray and greystones seems like a tall feat. that's assuming you double track parts of the corridor south of Greystones to wicklow as well, potentially in an SAC.

Charging infrastructure aside, could they reach 2tph by running trains in the same direction back-to-back(~5 minutes apart) through Bray head? It is difficult with current infrastructure but not impossible. Looking at timetables for Rosslare and Greystones services, it seems to be how they schedule Rosslare services around Greystones servics so they can stay at 2tph. If they were able to consistently do that, it could allow for Wicklow town to have 2tph.

It of course means that Greystones and Wicklow services would always be right after each other which isn't ideal, but it at least might be possible without affecting existing Greystones services. As well I think it would mean anytime a Rosslare service is scheduled a Wicklow service would need to be cancelled in its place.

Unfortunately I think to practically reach that frequency (ie, not repeat the August timetables), the 2-3km between Greystones and the last tunnel through Bray head needs to be twin-tracked. And like you mention that doesn't address improvements required for that frequency south of Greystones, which at absolute minimum would require a passing loop.

Charging infrastructure aside, could they reach 2tph by running trains in the same direction back-to-back(~5 minutes apart) through Bray head?

this already happens several times during the day. I think Bray Head is divided into 2 or 3 signalling section, once a train has cleared the first one a second train can enter. 07.48 Commuter is followed by the 07:54 Dart for example

that's assuming you double track parts of the corridor south of Greystones to wicklow as well, potentially in an SAC.

There was a loop between Kilcoole and Newcastle in the distant past, but I really doubt they will double any of it, it's about 15 minutes journey from Greystones to Wicklow so an hourly service is easily doable without the need for loops.

it would allow one extra path, so a 20 min frequency as opposed to the current 30 min - it's about 2km. Jacobs Engineering did a report on this 5(!) years ago.

But it seems in the Dart+ plan (any day now as they've been saying for 2 years) they're only going to double from the tunnel as far as the small crossing at the grove, as they think that will allow the same frequency and going all the way to the station isn't worth the heavy engineering that would involve.

wouldn't think so.

realistically it should contain work to get a longer DART train stopping at kilcoole and Wicklow (platform extensions and track work), some resignalling/ETCS, and substation + charging infrastructure at Wicklow. there'll be other ancillary work but those are likely to be the main works.

The timetable will need to consider the BEMU path and how it works with the Rosslare service and other DART services. . Although we probably won't know the timetable until BEMUs start operating to Drogheda (other than 1 BEMU per hour in each direction).

How long do the trains take to charge up?

• Dart leaves Drogheda fully charged
• runs under battery to Malahide (40% of the charge used?)
• Continues to Bray or Dun Laoghaire or wherever using OHLE
• Returns to Drogheda, using another 40% on the battery section
• Now it needs to recharge, how long is that going to take?

existing Dart and commuter trains have a fairly quick turnaround.

I guess regen is effectively indirect charging off the OHLE - i.e. it uses the OHLE to accelerate then the braking charges the battery. I'd be interested to see figures, I don't know if they've published any so far other than the 80km range?

In the recent Oireachtas Committee meeting I think I remember Jim Meade saying 20 min charge time.

The new trains charge off the OHLE too, don't they, but not when taking power?

Its probably something like 20%-80%, at least that is a common "fast charge" area for many batteries. Though these BEMU batteries might be different.

Also, Greystones-Wicklow should be less than 20km so it It shouldn't have to charge at all before returning.

I have been looking through the debate again, on page 17 he said: "They can run under the wires and go to Droghedaand be charged, if necessary, in 20 minutes and be back out again." And on page 9: "We can charge the batteries in Drogheda or under the wires when they come back."

The debate in general is not very technical so it might not be to the minute, but I can imagine its fairly accurate.

No, the line was only ever single track. The tunnels at Bray Head are a big problem.