DART+ (DART Expansion)

That might be a future plan, but my understanding is that D+ isn't about adding stations, but about developing and upgrading the infrastructure to allow for a higher capacity network. That may lead to more stations later but it doesn't include stations itself. In the FAQ it specifically mentions that while D+ does not include plans for Cabra and Kylemore, D+ is designed so that they are still possible in the future. So it is possible with upgrades from D+ that it will allow for more stations in the future, but its just not part of D+.

It being 5 mins walk from the P&R to the existing station is beside the point. Moving the existing station slightly further north and making it accessible from the La Touche bridge would bring it closer to the main town core and much of it's population. With a proper P&R station, the current station car parks could become mostly bike parking plus blue badge spaces and a plaza on the seaward side. The P&R station could also have a bike parking building like at Metrolink stations and would only be 5 min cycle from Charlesland.

At Redford, a new station should be primarily accessed by foot/bike and local bus, a car park shouldn't be provided. After that, access would only be needed for maintenance, etc.

My thinking is that the arse has been cut out of DART+ Coastal South anyway so there should be plenty in the kitty for improvements at the southern end where there are big benefits to be had for relatively small investment. Apart from the capital cost, attracting more people to DART brings down the marginal cost of providing the service, no point in providing extra capacity if you can't attract more people to use it. The existing Greystones station doesn't really work for anyone, a proper town centre station and a proper P&R station would be much better.

20% state of charge is the low end of the range. Turnaround time is about 15minutes at both stations. It may be quicker over time but they're conservatively assuming not to charge off the wires.

they do scenario tests based off different timetables to see how the battery charge is affected, which gives different assumptions for charging time. In reality we won't know until they start operating them. by not investing in infrastructure we've ended up as a front runner for battery technology implementation.

Really want it to be a success so we can rollout Cork and other schemes much quicker than full line upgrades will take. Drogheda BEMU and possibly Wicklow dont need Railway Orders, direct planning application to the authority.

OHLE can catch up at a later stage if needed. The traction substation investment is suitable for both both BEMU and EMU, so much of the initial investment wouldn't go to waste and provide quicker delivery of services.

The next round of challenge is that it's unlikely there's enough electricity in the grid to connect all the substations needed along each DART+ corridor to deliver the planned timetabled services.

grid capacity and connections are a moving target until you can guarantee the grid operator of the need. now moving into this space which is a difficult one in the current environment. there's a reason Eirgrid has proposals to upgrade the 220kv network across the city.

there are plans for a greenway between Greystones and Wicklow and Irish Rail are also working on a very extensive coastal protection plan. I'd expect any doubling or passing loops to tie into those plans, but equally I don't expect they'll actually double any of it as it's not necessary for an hourly service.

IE have closed one of the two car parks at Drogheda to facilitate construction of the charging infrastructure for DART+. The main one is also restricted for related works. But seeing the comments on Facebook, the feedback is all negative, people losing the plot over it. One commented "the DART is never coming to Drogheda and you know it." Some serious nay-sayers out there when the infrastructure is literally being built.

4.3 kWh/km would be very low unless you are subtracting the recovered energy in braking, you would be looking at closer to 7-8kWh/km for a train of this type without regeneration, its classically 2kWh/km per carriage give or take a bit

While the new train will certainly be more efficient all the extra toys onboard, AC etc does eat into that. 8100 fleet has a solid state chopper drive not a old fashioned resistance cut out so should be fairly light on the energy, but it doesn't regenerate, only rheostatic.

So the EMU's will have a higher number as they cannot be guaranteed the OHLE will be receptive for regeneration at all times, you make back around 20% but this drops to 12-15% under typical conditions, you need other trains under power. As the DART network gets bigger and more trains are moving the value goes up, first train of the day effectively gets 0%

The gird is fine, talks with ESB Networks have been ongoing for a long time so there isn't a risk here.

They would use one of the loop platforms at Clongriffin.

It’ll be a four track station.

That leaves two tracks for through services.

Few more pictures surfacing.

No, the two central platforms would be for through services, be they DART, Enterprise or whatever.

The other two are loops which can be used by terminating trains or for trains to be overtaken.

Energy is only partly dependent on voltage.. Energy (Joules, watt-hours or kilowatt-hours.. these are just different units for the same thing) is the sum of power over time. Power (Watts or kW) is an instantaneous measure and is voltage multiplied by current. You can choose any voltage and current combination to reach the amount of power you need.

The lower the voltage, the more current you need to supply in order to transfer the required power. Higher line voltage allows for thinner conductors (because current is lower), but very high voltage, especially DC voltage, is a higher safety risk.

Direct current (DC, static voltage) systems are not used above 3000 V: beyond that, AC is preferred as it allows more efficient power transmission over distance, and it also fits better with national grids, which are all AC. The reason suburban rail systems tend to use DC is largely historical: these trains need to start, stop and adjust speed regularly, but no efficient way of reducing AC power (for speed control) was available until the latter part of the 20th century with the invention of solid-state thyristors (basically the thing that makes light dimmers work). DC has advantages over AC in shorter-distance networks, which is why DART+ is sticking with the existing 1500 V, but future inter-city electrification will most likely use 25 kV AC.

no

I'll admit that having looked at it a bit before, it seems a little bit of a disappointment and confusion that with the DART system planned to enlarge fairly exponentially, that it didn't upgrade to 3kV or more (including inter-city proposed 25kV AC on same extended routes), seeing that there would seem to be potential approximate 20% electrical running costs savings with 3kV DC over 1.5kV DC (according to Netherlands studies) among some other advantages.

Both the French and Netherlanders seem to have looked at 9kV DC and 3kV DC alternatives to their 1.5kV DC existing systems, though ironically some Baltic, Eastern and Central European countries with 3kV DC systems look to replacing them them with 25kV AC. But in the latter countries instances i'd venture that is easily enough explained in that they are looking to do wholesale replacements of more ageing Soviet-era equipment, want to get rid of Soviet-era type system (a bit like us painting the post boxes Green on independence), and to upgrade inter-city lines for potentially much higher speeds, and importantly for inter-city links to other adjoining such systems. That said, Italy manages some high-speed lines (around 220kph?) with 3kV DC i believe, and as above, SNCF and Prorail (France and Netherlands) seeming to discard 25kV AC change from 1.5kV DC lines, presumably on non top flight intercity but still very substantial national systems for cost reasons.

There was a circa 2019 paper completed for Irish Rail about electrification feasibility for the DART expansion, that plumbed for 1.5kV DC for various convenience reasons and importantly due to tunnel and bridge restrictions mostly to the existing southside DART.

I'd imagine that some day there maybe some EU project to upgrade 1.5kV DC systems in some way, and maybe at that point the DART system may get involved. In terms of power, i've mentioned on Boards' the differences between some of the DC systems in west Europe (havent looked just now) and asked what the DART systems 1.5kV DC was, but it seems the French 1.5kV DC can power up to 4,400kW at 3000 amperage, but that the Italian 3kV DC might be to 3000kW(?) versus Belgium's 3kV DC at 4000kW(?)… I think I saw somewhere that the Amps of the Netherlands and Belgium DC systems were the same, and more than Italy's DC system?

Also, discussion in below forum about using 2 instead of 1 wire (and pantograph) to get more power into trains when leaving stations, and a comment that 2 wires were standard for Italian DC lines, and 3 wires in some places.

Discussion also below, that a theoretical 9kV DC (medium voltage systems/ MVDC) in France would be compatible with 1.5kV DC existing OHLE, and some discussion of correlations to efficiencies, maximum powers, existing OHLE, similarities to 25kV DC and national grids etc, with 12kV DC mentioned in this regard as exceeding some of these.

Medium voltage DC for affordable electrification | RailUK Forums

MVDC Railway Traction Power Systems; State-of-the Art, Opportunities, and Challenges

Railway capacity effects of ERTMS, 3 KV DC overhead power and ATO on a Dutch railway network - University of Twente Student Theses (just a student's abstract)

Rly Power Supply in Europe (re: a 2005 seminar for standardisation of rail electrical supply in the EU)