DART+ (DART Expansion)

thomasj

https://www.boards.ie/discussion/comment/120394866#Comment_120394866

I would say the 8 paths per hour (24 services) would be the 3 from Drogheda and 2 from Laytown and the rest being the Dundalk/Newry/Belfast services

LucianBelmau

https://www.boards.ie/discussion/comment/120388449#Comment_120388449

If all of this really goes through, in the next 20 years the Cabra/Glasnevin area is bound to be one of the best served by rail transport in Dublin, with 3 luas stops (Broombridge/Cabra/Phibsboro), a Dart West station (Broombridge), a Dart South-West station (Cabra East?), and a Metrolink/Dart station (Glasnevin). If they ever build a Luas to Blanch the Navan road might also see more rail coming, but that sounds more like a pipe dream atm 😅

CatInABox

Photos and video of the new dart fleet mock up have been released.

https://twitter.com/thejournal_ie/status/1641004927051878402?s=20

p_haugh

Irish rails tweet about it....

https://twitter.com/IrishRail/status/1640975071446548480

bk

Looks great, I really love the colour scheme outside.

It mentions charging points, but I don't see any in the video, will they have USB plugs in the back of the seats like on the buses?

DoctorPan

https://www.boards.ie/discussion/comment/120414711#Comment_120414711

Think the USB ports are under the seats in the area between the two.

AngryLips

Overall less seating it seems.

goingnowhere

https://www.boards.ie/discussion/comment/120414711#Comment_120414711

USB A+C ports are provided

VonLuck

https://www.boards.ie/discussion/comment/120415212#Comment_120415212

Hard to tell. The article says that each of the individual carriages are shorter, but the overall length of the trains will be the same. There are also folding chairs in the bike and disabled areas which may make it seem like there are fewer seats.

Zebra3

https://www.boards.ie/discussion/comment/120415561#Comment_120415561

Something that was in the original DART carriages back in the day.

LXFlyer

https://www.boards.ie/discussion/comment/120415594#Comment_120415594

They were indeed, but they were in the doorways which caused an obstruction.

lucernarian

https://www.boards.ie/discussion/comment/120395003#Comment_120395003

And what about the max speed of the new BEMUs? If I'm not mistaken both the 29ks and the existing dart fleet have bogies limited to 70 MPH and most of the track north of Malahide has an 80-90 MPH limit.

"It's a regularly-stopping service" I hear you say but even the current 29k fleet will routinely hit its max 70 MPH between stations, these stretches: Drogheda-Laytown, Balbriggan-Skerries and Skerries-Rush & Lusk stand out in particular for having higher line speeds than the 29ks can reach.

Maybe it's already been specced and the 52 minutes Connolly to Drogheda running time with the BEMUs is realistic. But the reality is that the Enterprise service in particular will be impacted. Based on the Clongriffin station "quad-tracking" and nothing else being done, the Enterprise will probably need 46 minutes to go from Connolly to Drogheda when operating alongside Dart+ if more than 50% of the planned Dart+ coastal services are actually deployed.

This means Dublin to Belfast journey times will increase to between 2hr20mins and 2hr30mins based on as-is service and no known track works to increase speeds elsewhere, while the quickest 33 minute journeys from Drogheda to Connolly will be a thing of the past.

DoctorPan

https://www.boards.ie/discussion/comment/120468776#Comment_120468776

The X'Trapolis family of units, have a design speed of 89mph and operating speed of 81mph. Reasonable to believe until stated otherwise the BEMU/EMU fleet will have a similar top speed.

I agree regarding the Enterprise, Quad tracking should never have been dropped to save costs. It was feasible and its needed.

lucernarian

https://www.boards.ie/discussion/comment/120469632#Comment_120469632

It seems there are no good estimates of costs or options as to what extent this should be carried out, but estimates from the past suggested 3-tracking between Clontarf Road and Clongriffin would be a lot more cost effective (like €300 million Vs €800 million in an older estimate) and would also comfortably accommodate planned/projected service patterns along with an hourly enterprise service. It would make timetabling far more flexible to have 4 but with no more than one train per hour, I don't see the benefit of significantly increasing potential costs and land take issues along the eastern side in particular.

If platforms aren't required for this 3rd track (or indeed quad-tracking), this would also make design much simpler and cost-effective and it pains me how these options were never really explored in the dart coastal docs I've seen so far. Seems like the NTA's attitude is that it's someone else's problem/budget to fix.

About the design speed Vs operational speed, I'm not sure what operational speed implies here. Will they actually be used at 89MPH routinely? The difference is what, maybe 4 minutes in journey length but this is important if maximising capacity is the intention and a 52 minute journey time is realistic. The CAF 29k sets, like their CAF 3k brethren up north are also capable of 90MPH and yet they were built for a lower max speed....

CatInABox

https://www.boards.ie/discussion/comment/120470038#Comment_120470038

Yeah, from comments from knowledgeable people on here, it seems that the NTA contorted themselves so that they could say that nothing was needed Connolly to Howth Junction.

bk

"Yeah, from comments from knowledgeable people on here, it seems that the NTA contorted themselves so that they could say that nothing was needed Connolly to Howth Junction."

I'd suspect that the NTA were worried about the poltical fallout over CPO'ing large number of homes and if doing so might jeopardise the entire Dart+ project.

Add to that the issue of the intercity service involving two different states and all the ongoing issues up North.

It might be unpopular to say, but Dart+ is vastly more important then the Belfast intercity, specially given the quality of the Motorway. I suspect they felt better to limit the risk to the DART+ project, get it done and then triple/quad tracking can be tackled in a future project.

LXFlyer

You have to remember that the NTA have nothing to do with the Enterprise service - it’s controlled by the two railway companies and the two government departments in Ireland and NI.

So the funding for the necessary infrastructure to deliver a faster Enterprise will have to come from elsewhere.

It does however beggar belief that the Northern Line capacity isn’t being enhanced to allow for faster long distance commuter services and the Enterprise at the same time as the DART+ works. Instead, both are being consigned to trundle along between stopping DART services.

goingnowhere

29k is a 75mph train, yes it can go faster but its not by design capable of cruising at 90mph like the C3k which has more installed power. It also lacks yaw dampers which are typically a must have to go above 75mph

DART+ fleet will be 140kph design speed and have an acceleration rate greater than the current DART fleet so will leave a 29k for dust

4 minutes off journey time seems very pessimistic, closer to 10 minutes more likely as its unbroken 90mph from Malahide to Drogheda. DART+ would be at 90mph before a 29k even got to 60mph

lucernarian

https://www.boards.ie/discussion/comment/120471925#Comment_120471925

Not sure if you missed the point where I mentioned a "4 minutes difference" but this was regarding the difference between the quoted operational speed of 80MPH and the design speed of 89 mph / 140 kph, all other things like the acceleration rate being equal. It wasn't a comparison with the 29k's. The xtrapolis series are not able to reach the full 143kph on the line as it is (but I'm more interested in whether they can consistently reach 140kph as tendered).

murphaph

They should have at least quad tracked a few stations to allow passing while DARTs stop anyway. That's how it works on my suburban line into Berlin which is only twin track and it's the main line between Berlin and Hamburg with regular Regional Express, IC and ICE services passing at 200km/h while regional trains wait at platforms. Not every station is quad tracked. The next station up the line from us has no lassing loops and the regional trains block the main line when stopping but the station after that has passing loops again and so on.

Zebra3

They could even have just quad tracked a fair bit of the line north of Clongriffen relatively easily.

L1011

They could even have just quad tracked Clongriffin itself! Four platform faces but three tracks currently.

murphaph

https://www.boards.ie/discussion/comment/120475552#Comment_120475552

Absolute madness not to add the fourth track and allow scheduled passing there at least as a first step. Such a easy win one would have thought. There is no way to avoid quad tracking much of the line in the longer term, at least if we are in any way serious about running trains. Starting with the stations themselves is a solid plan. The dots can always be joined later if it's determined that "only" providing passing opportunites at stations is insufficient (personally I would be amazed if quad tracking all the stations wasn't actually enough to sort the timetable out BUT there's no redundancy so if a train fails between stations, the entire up or down line is still blocked, so there's an additional benefit to quad tracking the lot but it isn't necessary from day one, but some quad tracking to allow passing should be included from day one. Here's my local station which google kindly photographed with 2 regional trains at the platforms allowing any would be passing ICE train to move through the station at line speed:

https://goo.gl/maps/vuX2GuyP5wS9qhvk8

DoctorPan

https://www.boards.ie/discussion/comment/120475552#Comment_120475552

They are installing the fourth track in Clongriffin as part of the project.

murphaph

https://www.boards.ie/discussion/comment/120476454#Comment_120476454

That's good to hear. A solid first step. Hopefully a few more stations south of there will be rebuilt with passing loops as time goes on. It's a shame that these things have to be so softly softly for fear of an angry article in one of the broadsheets setting alarm bells ringing in constituency offices up and down the line.

LXFlyer

Operationally to allow for realistic Enterprise and outer suburban journey times with a 10-minute DART service, there needs to be an ability for those trains to overtake DART services between Clontarf Road and Raheny either using three tracks or ideally four.

The buildings are too close to the railway permanent way around Kilbarrack to allow for more tracks.

Then there needs to be the ability to overtake between Howth Junction and Malahide.

Certainly the southbound loop at Clongriffin is needed, but really they need four track using dynamic loops along there, because otherwise the DART has to wait at Clongriffin Station for the manoeuvre to take place. You really need to be able to overtake with both trains on the move.

The Enterprise service is crucified by the lack of overtaking abilities between Connolly and Malahide.

North of Malahide, it’ll depend on the proposed DART frequency, but again overtaking using dynamic loops will be needed somewhere, along with proper turn back facilities off the running lines.

One would hope that some of this could be funded through EU/International supports, but there is no doubt in my mind that there will have to be more tracks installed if the services are to be competitively timed south of the border.

A1ACo

Just wondering if regard to DART+ would it be reasonably, and technically feasible (and overall worthwhile) to:

1.     Upgrade existing 1.5kV DC DART network to 3kV DC?

2.     Upgrade original (LHB), and later generation (Tokyu) DARTs, to 3kV DC?

3.     Use 3kv DC instead for future DART lines, and DART trains (X’trapolis) on order? 

Just as, I was a little surprised when I saw it was planned to go as far up the Northern Line as Drogheda (circa 37km), with the proposed DART electrification, not with 25kV AC,.. but extending existing 1.5kV DC – even though 25kV has for years been mentioned for any future electrification from Dublin to Cork, and sometimes mooted for after that, any later Dublin to Belfast electrification.

After looking into it a bit, there is a 2019 DART+ rail electrification assessment document on-line ...that essentially seems to say that; while 25Kv AC would be most ideal, and the modern standard, that the track height changes required for the Bray/ Greystones tunnels, and other tunnels and bridges to the Dún Laoghaire area, would be too expensive and difficult, etc.. 

It is also appears to be argued, that using the existing 1.5kV DC for the extended system, would allow for cross-use with the existing DARTs, between the old and extended systems, and that advise from manufacturers was that; converting existing DARTs (to 25kv AC), would be close to the cost of purchasing new stock.

Just wondering then,

a.     If the clearances for 3 kv would be more achievable?

b.     If it is decided to upgrade the existing old (LHB) DARTs, could they reasonably also be altered to 3kv at same time… (though the newer generation (Tokyu would have to be too).

And would it be worth it?

For comparison – though a much more intensive system – it seems to have been concluded in one quarter in the Netherlands - ProRail - in very recent years; that while converting from 1.5kv DC, to 25kv AC would be best, that it would be too costly, and disruptive - but that 3 kv instead… - would deliver many of the benefits, though not all. (and a cost difference, of 25kv AC- vs - 3kv DC conversion, of roughly €10 billion (to 25kv) - vs. - €1 billion (to 3kv)). Various benefits of 3 kv over 1.5kv were mentioned.

Anyway, related reading material see below (can't post links)

a document from the Netherlands, an online ‘Thesis’ - about 1.5 kv to 3 kv named as thesis Operational transitions in railway infrastructure.

Otherwise – various mentions on Netherlands ‘ProRail’ (rail infrastructure organisation) website about potential conversion from 1.5kv to 3 kv – and I found a document from them about this consideration once… – but can't find it at the moment.

lucernarian

https://www.boards.ie/discussion/comment/120476522#Comment_120476522

I think that's a fair appraisal of the situation - but I wanted to add that the Dart+ modelling and options documents look like they have been prepared to maximise the capacity available on the heavy rail routes throughout Dublin and to optimise the cost to benefit through capacity increases in tandem with feeder buses and exploiting network connectivity. This was the basis for the Dart+ options not recommending the dart+ tunnel for now (that apparently delivers only +20,000 extra passenger movements).

We see that the project will deliver quad-tracking for the Heuston station approaches as the volume of intercity traffic to the rest of the country is far higher than that for the northern line. And the Dart+ proposal doesn't really interfere with an hourly enterprise service (if Dundalk-only services are basically ran as a shuttle to Drogheda). There seems to be no official desire to pursue 2 hour journeys for the enterprise, as it doesn't seem to bring capacity benefits that the hourly service definitely would bring, unless *gasp* users would flock to bus services in their droves when Dublin to Belfast takes the 2hrs and 30 minutes that I predict is the outcome of Dart+ coastal.

You'd probably need some other radical proposal like a rail line from the northern line to e.g. Ashbourne via Airport or else using the Drogheda-Navan railway for regional trains to justify the significant capacity and cost that full quad-tracking provides, on top of building more stations to serve growing areas like e.g. Drogheda North.

Solving the journey time problem and adding additional peak time capacity alone can both be achieved with a much more simple third track addition from Clontarf Road to e.g. Raheny alongside the 4th platform at Clongriffin and Malahide layout change. An hourly enterprise service taking 2hrs 5 minutes can be achieved with this alone (or possibly need 3 tracking / quad dynamic loops between Balbriggan and Skerries). But it would be not nearly as reliable or beneficial as full 3 track running to Clongriffin which would offer clear capacity improvements at peak times.

I remember bk discussed a separate heavy rail tunnel solution for northern Dublin and this might be the long term solution for higher-speed rail to Belfast along with unlocking more potential trip generation than northern line upgrades can accomplish

LXFlyer

Again, I have to reinforce the point that I made earlier, which is the NTA have nothing to do with the Enterprise. It is funded directly by the two government departments.

Therefore whether DART+ impacts on it or not isn’t the NTA’s concern.

Funding for the solutions for the necessary improvements in the Enterprise journey times will have to be sourced elsewhere, and I’m of the view that is what the railway company will be doing, but not necessarily at the same time as DART+, although with delivery times slipping for that it’s possible that the two could be piggy backed on one another.

Also, there’s been no suggestion that the Dundalk services will not operate to/from Dublin. I don’t know where you’re getting the notion that they would be a shuttle to/from Drogheda to Dundalk.

Sligo and Rosslare line services also face longer journey times in the greater Dublin area, although some of that be recovered further along the routes from less time spent at passing loops.

Realistically I don’t see a brand new line being built - look at the battle to just get Metrolink past planning.

I do however see capacity enhancing improvements on existing lines as being the realistic option.

Pete_Cavan

Additional track(s) between Clontarf Road and Howth Junction isn't realistic without buying out a couple of hundred homes, which isn't realistic in itself (both in terms of cost and public acceptance).