Dunder Mifflin wrote: » Thanks, but I was looking for something a more bit more detailed than what's included in the General Linear Works section, unless I'm missing it. Does anyone have any experience of what the practical impact of the electrification works on the surrounding area is?
River Suir wrote: » Are you looking for a detailed explanation in order to submit an objection?
Dunder Mifflin wrote: » What’s exactly is involved with electrifying an existing train line? Is there any major construction required on the tracks or surrounding areas? Are the electricity lines the only major things needed? If anyone has any details or links to IR documents/presentations on it I’d appreciate it.
Empire o de Sun wrote: » I'm just wondering, are they not aiming to eventually have the network at 25 kV AC? Why not build the new lines as 25 kV AC and use the new bi voltage trains on them so they can run on the new and old network. And keep the old Darts on the coastal route. Will the new Darts be AC/DC
prinzeugen wrote: » Trains can switch on the move as happens going in/out of Holland. The problem is that you need have a long neutral section not just in the OHLE but on the track for return current/signaling etc. On a high speed line that's not a problem as the train can coast through it but on a slow speed system like the DART there is a risk that the train could come to a stand in the neutral section and become stranded.
Sam Russell wrote: » Sounds tricky - would those ***** that set out to create mayhem try to stop the train in the gap? I think we might need battery back up of some sort.
loyatemu wrote: » why, it's going to be 1500V everywhere.
Empire o de Sun wrote: » If the DART ran on a dedicated network it could have it's own voltage that would be better for an urban system, the Berlin S-bahn is a example I know of (750 V DC). But having two different voltages on a shared network (Dart / suburban / intercity) in the future, will that not add complexity? Thameslink in london switches from AC to a DC system. I think this is done while the train is stationary in a Farringdon station. Looking at the map of europe, I see only a few countries use a mix voltage on mainline operations such as France and the UK.
CatInABox wrote: » I believe that I may have caused some confusion when the tender first came out, by speculating that the Dart expansion had provision for both methods of electrification (1500v DC and 25kV AC), but that was only from reading way too much into one line of the tender. I've seen no evidence since to suggest my speculation was right, and in fact it's the opposite, it really looks like there's only 1500v DC support on the new trains. The first tranche of the new DARTs are looking like they're bi-mode, but that's Diesel and 1500v DC, no AC support at all. This is to allow a bit more flexibility on their usage. Sorry if I've raised hopes back then, not my intention at all. No idea if the project will include any provision for AC at all either, i.e. clearances, etc.
CatInABox wrote: » The first tranche of the new DARTs are looking like they're bi-mode, but that's Diesel and 1500v DC, no AC support at all. This is to allow a bit more flexibility on their usage.
bk wrote: » I thought the plan was for bi-mode battery and 1500v DC? Have they scrapped the battery idea and going Diesel instead? Given that electrification of the intercity lines is 15+ years off, the development of battery tech over that time, might leave for some interesting possibilities. Cork to Dublin could be 25kV AC, but end before Hazelhatch. Batteries on the intercity train could then power the train from Hazelhatch into Hueston. There is the idea that with battery tech, you could avoid needing to wire the entire length of lines. Instead you could have sections of wired track, where the train powers up the battery to run on the unwired sections. Can reduce the cost of electrification, in particular avoiding needing to rebuild low bridges or other areas where the electrification would be difficult (areas prone to flooding).
bk wrote: » There is the idea that with battery tech, you could avoid needing to wire the entire length of lines. Instead you could have sections of wired track, where the train powers up the battery to run on the unwired sections. Can reduce the cost of electrification, in particular avoiding needing to rebuild low bridges or other areas where the electrification would be difficult (areas prone to flooding).
bk wrote: » I thought the plan was for bi-mode battery and 1500v DC? Have they scrapped the battery idea and going Diesel instead?
CatInABox wrote: » Sorry, it's definitely electric. I'm having a slight mare of a week, where everything that can go wrong, has gone wrong. I looked up the announcement that it was battery and electric, and then posted diesel and electric.
DoctorPan wrote: » From Peter Smythe and Jim Meade presentations to Engineers Ireland and IRRS. They are sticking with 1500DC for this round of expansion of wiring to allow the existing stock to be used. Any further expansions will be done at 25kV AC and over time, the DART network could be converted to the AC network once the 8100s, 8500s and 8510s are withdrawn. Smythe outlined that the new DART stock designed with the average lifespan of 40 years and how the network is expected to change over their lifetime. They are to be 1500 DC and the first batch are to be fitted with batteries as they are expected to be delievered before the wires are extended to Maynooth, Drogheda, Hazelhatch and M3 Parkway so that they enter service immediately as temporary BEMUs for a year or so, once the wiring is complete, they'll be stripped of batteries and enter service as pure EMUs. Smythe said by doing it this way allows Irish Rail to get a new fleet quickly but also creates pressure on the government to prevent the situation of a brand new fleet sitting up in Inchicore unusable as they haevn't invested in wiring the network.
