Advertisement
MODs please see this information notice in the mod's forum. Thanks!
Boards Golf Society are looking for new members for 2022...read about the society and their planned outings here!
How to add spoiler tags, edit posts, add images etc. How to - a user's guide to the new version of Boards

DART+ (DART Expansion)

1250251253255256260

Comments



  • gjim wrote: »
    Won't the batteries require new infrastructure for charging in the depots or at certain stations? And I guess new engineering facilities will be required. But all this infrastructure is intended to be temporary? It feels incredibly wasteful while at the same time introducing further risks in terms of project management.

    Installing a charging point at Drogheda and maybe a couple of other stations has a lot less project risks attached than electrifying the entire 35km between Malahide and Drogheda. The charging points and the power supply plus associated infrastructure to them will no doubt be useful when it comes to fully electrifying.

    The upgrade of the line to full electrification becomes a much more realistic prospect if there is already some electrical infra in place and the rolling stock is already there, only needing batteries removed. I don't see how any of that is wasteful or risky, it will actually mitigate risks. If the full electrification didn't proceed for any reason, its better to have the BEMUs operating for longer than continuing with diesels for however long.

    Electrifying the Maynooth lines first makes sense as not having that done limits the electrification possibility on the Kildare line to HH - Heuston, which hugely changes the cost/benefits of that element. Also, the service depot for the increased EMU fleet will be at Maynooth.




  • LXFlyer wrote: »
    The extra tracks on the Northern Line are expected to be delivered as part of the Dublin/Belfast line upgrade from what I’m hearing, rather than DART+.

    Because why get something done in one job when you can spread it across two jobs, eh? But seriously, what is the logic of electrifying a line that you're subsequently going to tear up to put extra tracks down?




  • AngryLips wrote: »
    Because why get something done in one job when you can spread it across two jobs, eh? But seriously, what is the logic of electrifying a line that you're subsequently going to tear up to put extra tracks down?

    Well it's two different funding pots - the DART+ is an NTA project, while the Dublin-Belfast line enhancement is in an international project that would be jointly EU-UK funded I presume. These things don't tend to work in tandem sadly.

    The NTA really aren't bothered about the Enterprise as it's nothing to do with them.

    The extra tracks being referred to are between Connolly and Howth Junction - it's already electrified there.




  • L1011 wrote: »
    The ability to draw on traction power for acceleration is not the same when its a DEMUs onboard generator as when its grid. And there is zero use for regenerative braking.

    Also, as far as I know, the 22000 class are not DEMU, being geared drive to the wheels; and this makes up a significant amount of the fleet to be replaced/transferred. Actually, do we have any DEMU units other than 29000s?

    edit: also, you drive harder/closer to the limits without the same environmental and noise impacts as doing it in anything diesel powered; not that I expect a working schedule to require that.
    That makes sense. The peak kW draw from an Li-ion pack is much higher than the relatively constant output from a diesel generator - thus providing higher torque.

    Interesting regarding the fact that most of the DMU fleet has mechanical transmission? For some reason, I had the impression that nearly all DMUs these days use electrical transmission.

    Electrical transmission for DMUs makes a lot of sense to me - quieter, more efficient, less polluting, less mechanics for easier maintenance, etc.. And presumably some DeMUs have a small amount of battery also which could be used to to recover energy during braking and to provide an acceleration boost - a bit like hybrid cars.




  • Apologies for interrupting the current discussions, but has the public feedback from the Dart+ West consultation been made available anywhere?


  • Advertisement


  • Correct me if I'm wrong, but I assume the batteries will charge via overhead wires at Drogheda, but also run and charge from the overhead wires when on the electrified sections of the Northern line.

    If that is the case, then those overhead wires and electrical systems in Drogheda would likely be used and be the basis for when the line is electrified anyway.

    So the only potential waste is the batteries and I could see some of these battery trains ending up elsewhere in the network like Cork commuter, etc. once Dublin is fully electrified.




  • On performance of BEMU's, interesting article about a BEMU in Germany:
    The Battery Talent 3 has an output at the wheel of 2MW under overhead electric and 1MW in battery mode, with maximum acceleration of 1.2m/s² in both configurations. Bombardier says the equivalent DMU would offer an output of just 800kW. Von Mach suggests that switching from DMUs to BEMUs on non-electrified lines would therefore offer performance benefits such as shorter sectional running times that could help to strengthen the business case for battery trains.

    https://www.railjournal.com/in_depth/battery-train-energises-race-to-replace-diesel




  • Pete_Cavan wrote: »
    Installing a charging point at Drogheda and maybe a couple of other stations has a lot less project risks attached than electrifying the entire 35km between Malahide and Drogheda. The charging points and the power supply plus associated infrastructure to them will no doubt be useful when it comes to fully electrifying.
    I'm not suggesting the project risk profile for full electrification is better than that of expanding the fleet with BEMUs.

    The fleet has to be renewed/expanded to an extent anyway, even without much of DART+.

    My question is why pick BEMUs which:
    - are a novel technology with respect to MU trains globally
    - have different operational characteristics compared to anything in the existing fleet - for example, battery charging will always be slower than pouring diesel into a tank
    - will require new charging infrastructure, maintenance facilities/workshop equipment
    - will require the development of engineering skills for maintenance,
    - will probably require horse trading with the unions over "driver training" etc.

    And all of which is intended to be retired in a few years?

    The lower risk option for me would be to buy a mix of new EMUs and DeMUs which would require none of the above.

    To answer my own question, there are a few plusses for the BEMU purchase:
    - BEMUs have fewer emissions
    - BEMUs will be easier to convert to EMU (although apparently EMU to DMU conversions and vis-versa are a "thing")

    But I'm not convinced that these advantages are enough to swing it? DART+ - despite its disappointing lack of ambition - is nonetheless a complex project and it feels weird that effort and resources will be diverted to integrate a novel train technology into existing operations - but that effort and resources will be redundant in a couple of years.




  • buffalo wrote: »
    Apologies for interrupting the current discussions, but has the public feedback from the Dart+ West consultation been made available anywhere?

    The latest update is here:

    https://www.dartplus.ie/en-ie/news/2021/update-on-dart-west-preferred-option-at-coolmine

    2nd consultation is due in July.




  • LXFlyer wrote: »
    The latest update is here:

    https://www.dartplus.ie/en-ie/news/2021/update-on-dart-west-preferred-option-at-coolmine

    2nd consultation is due in July.

    Thanks. I was hoping for a anonymised aggregate of all the responses and comments. I'd love to get an idea of the actual public feedback rather than a distilled version.


  • Advertisement


  • buffalo wrote: »
    Thanks. I was hoping for a anonymised aggregate of all the responses and comments. I'd love to get an idea of the actual public feedback rather than a distilled version.

    I suspect that will come with the 2nd consultation.




  • buffalo wrote: »
    Thanks. I was hoping for a anonymised aggregate of all the responses and comments. I'd love to get an idea of the actual public feedback rather than a distilled version.

    It's only just closed, there's no way they'd collate that so fast




  • MJohnston wrote: »
    It's only just closed, there's no way they'd collate that so fast

    Not that west, the other west!

    I get them mixed up too.




  • MJohnston wrote: »
    It's only just closed, there's no way they'd collate that so fast

    That poster is talking about the Maynooth/M3 line.




  • gjim I think you are overstating the difference between an EMU and BEMU. A BEMU is basically an EMU with a bunch of batteries on the roof. More or less everything else is much the same.

    Every downside of BEMU's you list is the same for Dublin Bus, Bus Eireann and pretty much every bus, coach, truck and fleet operator who will be switching to EV's over the next 10 years.

    If anything I'd argue that IR should have an easier time of it then the above companies, due to their existing experience working with EMU's and overhead electrical systems.

    Buying DeMU's would not be an option as they aren't a zero emission vehicle and would thus be counter to government policy going forward. The options are EMU, BEMU or hydrogen fuel cell.




  • :facepalm: I see now my mistake!




  • Only seeing now the update on DART West for the Coolmine Road crossing. So there won't be a new bridge. The existing bridges are far away and major road changes would be needed in order to get traffic from the closure area to Diswellstown Road in particular. I'm not generally a fan of closing level crossings without providing a new alternative.




  • spacetweek wrote: »
    Only seeing now the update on DART West for the Coolmine Road crossing. So there won't be a new bridge. The existing bridges are far away and major road changes would be needed in order to get traffic from the closure area to Diswellstown Road in particular. I'm not generally a fan of closing level crossings without providing a new alternative.

    Well therein lies the conundrum - the locals don't want the proposed bridge.

    So what do you do?




  • I suspect if you ran a referendum within 3km of Coolmine station you'd end up with support for a new bridge. There is a hyper local campaign to prevent it.
    They've probably picked the best balance for the moment.




  • liamog wrote: »
    I suspect if you ran a referendum within 3km of Coolmine station you'd end up with support for a new bridge. There is a hyper local campaign to prevent it.
    They've probably picked the best balance for the moment.

    Well, if they close the gates, the local support for a bridge will either appear or not. If it does in sufficient numbers, they can design and build the bridge. If not, they save a few bob.

    Everyone happy.


  • Advertisement


  • I am big advocate for adding extra tracks to the Northern Line but I haven’t seen anything to suggest it will be done. The only change will be a southbound passing loop at Clongriffin.

    I wish the NTA luck when they try to close Sandymounts 5 level crossings. It’s going to be worse than Dunville avenue.

    I'm working on DART + Coastal and Triple/Quad Tracking is part of our contract.




  • DoctorPan wrote: »
    I'm working on DART + Coastal and Triple/Quad Tracking is part of our contract.

    Are you in a position to reveal generally what the solutions proposed might be?




  • bk wrote: »
    gjim I think you are overstating the difference between an EMU and BEMU. A BEMU is basically an EMU with a bunch of batteries on the roof. More or less everything else is much the same.

    Every downside of BEMU's you list is the same for Dublin Bus, Bus Eireann and pretty much every bus, coach, truck and fleet operator who will be switching to EV's over the next 10 years.

    If anything I'd argue that IR should have an easier time of it then the above companies, due to their existing experience working with EMU's and overhead electrical systems.

    Buying DeMU's would not be an option as they aren't a zero emission vehicle and would thus be counter to government policy going forward. The options are EMU, BEMU or hydrogen fuel cell.
    you could right that I'm getting into a flap over nothing, bk. However I had a look around at other commuter BEMU systems globally and maybe wikepedia is out of date in this regard since the latest dates seem to be 2019/2020, but there isn't any? Austria were trialing them and the Talent 3 project page says 7 trains to be delivered and that 21 trains had been ordered in Germany. The Japan BEMU is a tiny 20 train set that links two small towns 25k and 30k populations 20km apart. I don't like the idea of IR being the QA for a new train technology.

    I'm all for zero emissions so I get that part of the argument and agree with it.




  • DoctorPan wrote: »
    I'm working on DART + Coastal and Triple/Quad Tracking is part of our contract.

    That’s great to hear.

    I know it was considered as part of Dart Expansion options assessment to 4 track the Northern Line but was not brought forward. I think their approach was flawed as they only considered the Dart capacity uplift (2 tph) and not Enterprise/Commuter improvements that’s it would bring.




  • I am big advocate for adding extra tracks to the Northern Line but I haven’t seen anything to suggest it will be done. The only change will be a southbound passing loop at Clongriffin.

    I'm not yet an advocate of that, at least until other options have been considered, and I am surprised that Doctor Pan, above, seems to already be working on a contract to look into a 3-4 track proposal for the Northern Line.

    One of the options which I think should be considered would be to build two tracks between the Howth Road Bridge and the northern side of Clontarf Golf Course, parallel to the current line and gradually heading between overground (Howth Road Bridge) and underground (around Killester Station, the end of Collins Avenue, etc.). This would probably also include an edge of the land of Mount Temple School (Not The Edge of Mount Temple School:pac:)

    There are several factors which may favour this broad idea:

    (i) the gradients required to get from overground at Howth Road to, say, 6-7 metres below ground at a station at Killester seem to be very achievable (about 1m in 75m (12m or so over 900m) - for reference, the gradients required to get Northern line trains from their current level into the DART Underground proposal would have been about 1 in 45-50m);

    (ii) Irish Rail owns about 5% of the land occupied by Clontarf Golf Course - I don't know which bit that is, but I think it's a reasonable guess that it's the part closest to the railway line, and it may thus not have the same restrictions which apply to the long lease that the club has with the City Council for the vast majority of that space - in any case, construction there shouldn't be difficult, if it is deemed best for the community at large;

    (iii) It shouldn't be difficult to in some way integrate the underground and overground stations at Killester, if this is necessary, and there don't seem to be obvious hindrances to building a cut-and-cover railway line from that point to the Artane Roundabout and then along the Malahide Road to Coolock, Clarehall, etc, and beyond, perhaps to Malahide.

    This, to me, would represent an option which should be considered. The main negative, as I see it, is that it would posssibly require some minor realignment of the northern line on the southward approach to the Howth Road bridge, to accomodate a northbound 'Artane' line going under it, but overall that should be quite manageable.

    On the plus side, you'd save all the palaver of three/four-tracking of the northern DART line, with all the hassles and compulsory purchase, etc, that would be required, and you would instead end up with an extra DART line serving other areas which don't currently have it. And that DART would be broadly feeding into a 4-track section between East Wall and Connolly, where its interactions with the Enterprise and Dundalk arrows should not necessarily be a major problem.

    The costs issue is, of course, another factor. I can see that cut-and-cover along the Malahide Road should incur little, if any, in terms of compulsory purchase costs, and it seems likely that 3/4-tracking would require somewhat more.




  • This would probably also include an edge of the land of Mount Temple School (Not The Edge of Mount Temple School:pac:)

    This gave me a bit of a chuckle. Kinda glad now I actually read one of his posts for once!




  • Good!

    It appears to be about 4.7 km from the top of Clontarf Golf Course to the Mayne River (Belmayne) along the Malahide Road. Beyond that you could perhaps be looking at overground sections if further extension is desirable, e.g. to Malahide.

    Using a broad figure of 200 million euro per km (about the cost of the metro per km, it seems, using a TBM) such a project should come in at around 1.2 billion euro, when you include the Mount Temple/Golf Course bit. (Cut-and-cover might reduce that a small bit, but a tie-in with the Northern line near the Howth Road bridge - possibly requiring bridge replacement? - might wipe out any savings).

    It would be interesting to know what cost projections there are for 3/4-tracking the existing line to, say, Clongriffin - just south of the Mayne River. Doing that, of course, would not involve directly serving any new areas.




  • I'm not yet an advocate of that, at least until other options have been considered, and I am surprised that Doctor Pan, above, seems to already be working on a contract to look into a 3-4 track proposal for the Northern Line.

    One of the options which I think should be considered would be to build two tracks between the Howth Road Bridge and the northern side of Clontarf Golf Course, parallel to the current line and gradually heading between overground (Howth Road Bridge) and underground (around Killester Station, the end of Collins Avenue, etc.). This would probably also include an edge of the land of Mount Temple School (Not The Edge of Mount Temple School:pac:)

    There are several factors which may favour this broad idea:



    (iii) It shouldn't be difficult to in some way integrate the underground and overground stations at Killester, if this is necessary, and there don't seem to be obvious hindrances to building a cut-and-cover railway line from that point to the Artane Roundabout and then along the Malahide Road to Coolock, Clarehall, etc, and beyond, perhaps to Malahide.

    This, to me, would represent an option which should be considered. The main negative, as I see it, is that it would posssibly require some minor realignment of the northern line on the southward approach to the Howth Road bridge, to accomodate a northbound 'Artane' line going under it, but overall that should be quite manageable.

    On the plus side, you'd save all the palaver of three/four-tracking of the northern DART line, with all the hassles and compulsory purchase, etc, that would be required, and you would instead end up with an extra DART line serving other areas which don't currently have it. And that DART would be broadly feeding into a 4-track section between East Wall and Connolly, where its interactions with the Enterprise and Dundalk arrows should not necessarily be a major problem.

    The costs issue is, of course, another factor. I can see that cut-and-cover along the Malahide Road should incur little, if any, in terms of compulsory purchase costs, and it seems likely that 3/4-tracking would require somewhat more.

    The point of four tracking is not to benefit the Dart. The Dart is already much more important than Enterprise and Northern Line Commuters to IÉ. The point is to allow regular fast Enterprise and Express Commuter trains to overtake slow Darts .

    I'm open to building a tunnel instead of four tracking. However, the tunnel would be better off being for express trains only (no stations at all). Stations with 170m long platforms are really expensive. And you would have more freedom with the alignment if you didn't have to consider station locations.




  • The point of four tracking is not to benefit the Dart. The Dart is already much more important than Enterprise and Northern Line Commuters to IÉ. The point is to allow regular fast Enterprise and Express Commuter trains to overtake slow Darts .

    I'm open to building a tunnel instead of four tracking. However, the tunnel would be better off being for express trains only (no stations at all). Stations with 170m long platforms are really expensive. And you would have more freedom with the alignment if you didn't have to consider station locations.

    That can only work for electric trains.


  • Advertisement


  • Operationally the main need for three/four tracking is from between Clontarf Road and Killester to Raheny - that would allow na stopping DART to be overtaken before Howth Junction.


Advertisement