Re: [Tagging] Feature Proposal - RFC - 3rd and 4th rail (Michael Reichert)
Hi Garry, On 2020-06-13 18:49, Garry Keenor wrote: > Also, there are only 2 networks that I can identify worldwide that are 4th > rail, and I've tagged them both already. :-) You may have missed one I just discovered that the LIM lines of SkyTrain (Vancouver) have some kind of 4-rail system: "Two power rails (positive and negative) were chosen instead of the conventional single third rail system with return via the track, to eliminate electrolytic corrosion in underground structures and in the guideway itself. This dual power rail system also provides significant protection against ground faults." https://www.ejrcf.or.jp/jrtr/jrtr16/f44_vancouver.html#:~:text=Propulsion%20uses%20two%20Linear%20Induction,technology%20to%20mass%20transit%20systems. I haven't yet been able to find any decent images that show the topology of the 5 (2 running, 2 power, 1 propulsion) rails in cross-section Regards, Colin___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Feature Proposal - RFC - 3rd and 4th rail (Michael Reichert)
I think it is fairly unlikely that any more 4th rail will be built, and certainly not converted. It is a system which makes it difficult to detect earth faults, as well as making the design of junctions more complex. Not impossible though. best regards, Garry On Sun, 14 Jun 2020 at 12:22, Paul Allen wrote: > On Sat, 13 Jun 2020 at 17:50, Garry Keenor wrote: > >> Paul - thanks for the response. I struggle with the idea that someone >> would know that a route is electrified with a ground level contact system, >> but not how many rails there are. The possible sources are a) local >> knowledge, >> > > Or local-ish knowledge. On-line newspaper article saying the line has > been electrified (I'm local to me, and I know how to use the internet; the > newspaper is local to the line). > > b) wikipedia >> > > Never trust wikiepedia. :) > > and c) aerial imagery. >> > > Sometimes aerial imagery is crappy. Good enough to see that there are > no gantries for carrying an overhead line but not good enough to count > rails. Unlikely, particularly on a long line, but possible. > > >> All of these will, 9 times out of 10, define the system. Also, there are >> only 2 networks that I can identify worldwide that are 4th rail, and I've >> tagged them both already. :-) >> > > So when 8 more networks are converted to 4th rail, there's a risk that one > of > them (using your figures) can't be pinned down. :) > > I assume that more networks will be converted over time, or new ones will > be built as 4th rail. Or will they? > > -- > Paul > > ___ > Tagging mailing list > Tagging@openstreetmap.org > https://lists.openstreetmap.org/listinfo/tagging > ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Feature Proposal - RFC - 3rd and 4th rail (Michael Reichert)
On Sat, 13 Jun 2020 at 17:50, Garry Keenor wrote: > Paul - thanks for the response. I struggle with the idea that someone > would know that a route is electrified with a ground level contact system, > but not how many rails there are. The possible sources are a) local > knowledge, > Or local-ish knowledge. On-line newspaper article saying the line has been electrified (I'm local to me, and I know how to use the internet; the newspaper is local to the line). b) wikipedia > Never trust wikiepedia. :) and c) aerial imagery. > Sometimes aerial imagery is crappy. Good enough to see that there are no gantries for carrying an overhead line but not good enough to count rails. Unlikely, particularly on a long line, but possible. > All of these will, 9 times out of 10, define the system. Also, there are > only 2 networks that I can identify worldwide that are 4th rail, and I've > tagged them both already. :-) > So when 8 more networks are converted to 4th rail, there's a risk that one of them (using your figures) can't be pinned down. :) I assume that more networks will be converted over time, or new ones will be built as 4th rail. Or will they? -- Paul ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Feature Proposal - RFC - 3rd and 4th rail (Michael Reichert)
> there are only 2 networks that I can identify worldwide that are 4th rail, and I've tagged them both already. If that's the case, is it worth tagging the distinction between 3rd and 4th rail systems? If so, perhaps only the rare 4th rail systems need a new tag, and we can keep electried=rail for the vast majority of systems which are 3rd rail? – Joseph Eisenberg On Sat, Jun 13, 2020 at 9:50 AM Garry Keenor wrote: > > Paul - thanks for the response. I struggle with the idea that someone would know that a route is electrified with a ground level contact system, but not how many rails there are. The possible sources are a) local knowledge, b) wikipedia and c) aerial imagery. All of these will, 9 times out of 10, define the system. Also, there are only 2 networks that I can identify worldwide that are 4th rail, and I've tagged them both already. :-) > > best regards, > > Garry > > > On Thu, 11 Jun 2020 at 12:49, Paul Allen wrote: >> >> On Thu, 11 Jun 2020 at 08:57, Garry Keenor wrote: >>> >>> >>> Re: using electrified=rail to mean (3rd or 4th rail) >>> I'm not in favour of this one - railway electrification engineers (of which I am one) do not consider 4th rail to be a special case of 3rd rail, but rather a distinct system with its own electrical feeding arrangement. It would also run the risk of confusion in the mappers mind - they would read as far as electrified=rail in the tag wiki and miss the later option for 4th rail. I'm happy to leave electrified=rail to mean 3rd rail if that is what the group prefers. >> >> >> Using electrified=rail to mean 3 rails and having a sub-tag for 4 rails is a bad >> thing. But perhaps there is a case for retaining electrified=rail to mean "It's >> electrified using rails rather than contact line but I don't know how many rails." >> You mentioned that contact lines are often visible on aerial imagery. Mappers >> may know a route is electrified by other means (such as a newspaper article >> saying the route has been electrified) but don't know how many rails there are, >> only that there is no sign of a contact line. >> >> Argument against it: there may be a contact line but the imagery is too >> coarse for it to be visible or the mapper doesn't have the skill to >> interpret the image correctly so uses electrified=rail where it >> should be electrified=yes. >> >> -- >> Paul >> >> ___ >> Tagging mailing list >> Tagging@openstreetmap.org >> https://lists.openstreetmap.org/listinfo/tagging > > ___ > Tagging mailing list > Tagging@openstreetmap.org > https://lists.openstreetmap.org/listinfo/tagging ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Feature Proposal - RFC - 3rd and 4th rail (Michael Reichert)
Paul - thanks for the response. I struggle with the idea that someone would know that a route is electrified with a ground level contact system, but not how many rails there are. The possible sources are a) local knowledge, b) wikipedia and c) aerial imagery. All of these will, 9 times out of 10, define the system. Also, there are only 2 networks that I can identify worldwide that are 4th rail, and I've tagged them both already. :-) best regards, Garry On Thu, 11 Jun 2020 at 12:49, Paul Allen wrote: > On Thu, 11 Jun 2020 at 08:57, Garry Keenor wrote: > >> >> Re: using electrified=rail to mean (3rd or 4th rail) >> I'm not in favour of this one - railway electrification engineers (of >> which I am one) do not consider 4th rail to be a special case of 3rd rail, >> but rather a distinct system with its own electrical feeding arrangement. >> It would also run the risk of confusion in the mappers mind - they would >> read as far as electrified=rail in the tag wiki and miss the later option >> for 4th rail. I'm happy to leave electrified=rail to mean 3rd rail if that >> is what the group prefers. >> > > Using electrified=rail to mean 3 rails and having a sub-tag for 4 rails is > a bad > thing. But perhaps there is a case for retaining electrified=rail to mean > "It's > electrified using rails rather than contact line but I don't know how many > rails." > You mentioned that contact lines are often visible on aerial imagery. > Mappers > may know a route is electrified by other means (such as a newspaper article > saying the route has been electrified) but don't know how many rails there > are, > only that there is no sign of a contact line. > > Argument against it: there may be a contact line but the imagery is too > coarse for it to be visible or the mapper doesn't have the skill to > interpret the image correctly so uses electrified=rail where it > should be electrified=yes. > > -- > Paul > > ___ > Tagging mailing list > Tagging@openstreetmap.org > https://lists.openstreetmap.org/listinfo/tagging > ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Feature Proposal - RFC - 3rd and 4th rail (Michael Reichert)
> Using electrified=rail to mean 3 rails and having a sub-tag for 4 rails is a bad thing. +1 Volker ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Feature Proposal - RFC - 3rd and 4th rail (Michael Reichert)
On Thu, 11 Jun 2020 at 08:57, Garry Keenor wrote: > > Re: using electrified=rail to mean (3rd or 4th rail) > I'm not in favour of this one - railway electrification engineers (of > which I am one) do not consider 4th rail to be a special case of 3rd rail, > but rather a distinct system with its own electrical feeding arrangement. > It would also run the risk of confusion in the mappers mind - they would > read as far as electrified=rail in the tag wiki and miss the later option > for 4th rail. I'm happy to leave electrified=rail to mean 3rd rail if that > is what the group prefers. > Using electrified=rail to mean 3 rails and having a sub-tag for 4 rails is a bad thing. But perhaps there is a case for retaining electrified=rail to mean "It's electrified using rails rather than contact line but I don't know how many rails." You mentioned that contact lines are often visible on aerial imagery. Mappers may know a route is electrified by other means (such as a newspaper article saying the route has been electrified) but don't know how many rails there are, only that there is no sign of a contact line. Argument against it: there may be a contact line but the imagery is too coarse for it to be visible or the mapper doesn't have the skill to interpret the image correctly so uses electrified=rail where it should be electrified=yes. -- Paul ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
[Tagging] Feature Proposal - RFC - 3rd and 4th rail (Michael Reichert)
Michael, Thanks for your comments. I'm a bit behind so I'll try to catch up with your comments to date. Re: 3rd_rail/4th_rail vs 3rail/4rail I really don't mind and will go with the majority. Not sure how you determine a majority with this process! Re: using electrified=rail to mean (3rd or 4th rail) I'm not in favour of this one - railway electrification engineers (of which I am one) do not consider 4th rail to be a special case of 3rd rail, but rather a distinct system with its own electrical feeding arrangement. It would also run the risk of confusion in the mappers mind - they would read as far as electrified=rail in the tag wiki and miss the later option for 4th rail. I'm happy to leave electrified=rail to mean 3rd rail if that is what the group prefers. Leaving electrified=rail to mean only 3rd rail has the advantage that it reflects the current usage - with the exception of the London network (which I will retag) and the very small Milan Metro 1 line (which I'm also happy to retag). Voltages for individual rails We do have some thoughts on that which I will share in a later proposal, but I would like to keep this change discussion focused purely on electrification type. Dual voltage areas We do have a specific proposal/solution for that problem which I will share in a later proposal, but I would like to keep this change discussion focused purely on electrification type. 3 phase electrification II haven't thought about that one, let's get this proposal through the process and I'll put it on the list to think about. best regards, Garry best regards, Garry ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
