Hi Sergio, Thank you for feedbacks, my answers below.
One general reminder: I'm not the one who start to map nor line attachments, nor substations shared between pipelines and power lines. tower:type=anchor, tower:type=suspension and pipeline=substation were already widely used and reviewed. Tagging should be improved for the sake of benefits listed in proposed documents Le mer. 13 mars 2019 à 01:21, Sergio Manzi <s...@smz.it> a écrit : > So, your updated picture made it clear that it is the "insulator set" what > should be mapped with your newly proposed tag. I suppose that for power > lines the same would be true in case the "line attachment" would be through > a "pin insulator" or a "shackle insulator" or every other form of insulator. > In case of power line, the insulator set (chains + linking accessories) AND clamps. Yes it may be the same for other values which I can provide similar pictures > So, when one is supposed to use the "power=insulator" tag instead? > > The wiki for that tag (*which you wrote*) is describing insulators as "*Power > insulator linking a power line to a support*" and also "*It's a power > insulator linking an overhead line to another (grounded) infrastructure*". > > In the examples there is also a picture of a concrete portal with the > caption stating: "*Support : Insulators are used to anchor the power line > on a concrete portal*". > When the support is mapped as a separate object. For instance a portal mapped as a way. The shared node between the portal and the line gets power=insulator + proposed line_attachment. https://wiki.openstreetmap.org/wiki/File:Portal_portal_as_way.png > *So we should tag the same node as both a "power=insulator" and > "line_attachment=suspension", or should we map a distinct node for the > "line_attachment"?* > When power=insulator is applicable, the same node can get a line_attachment tag also. There is not always an insulator involved with line attachment. In case of a tower mapped as a node (most of them), we can't mix power=tower and power=insulator on the same object. > I would barely understand if you only had *two values* for > line_attachment *as properties of the "insulator" key*: suspension and > anchor, distinguishing if the vector of forces on an insulator add-up to an > essentially vertical vector because the "traction" forces of two catenaries > compensate each other and you just have a vertical component of force at > the binding post (*suspension*), or you don't have the compensation of > the two catenaries (the line is attached to a fixed post or the two > catenaries are not compensated) and you also have an horizontal component > of force that the binding post must sustain (*anchor*). Not much useful > to know, IMHO, but hey, who am I to judge that? > > But that's not the case, unhappily! In your proposal you also describe > "*shackle > insulators*" and "*pin insulators*" as "line attachments". For me they > should have been documented in the "insulator" key as types of insulators > (*yes, > Warin, I know you dislike "type" and it goes under your skin...*). > As Warin, I also dislike the type tags. Lines aren't always attached with insulators, unfortunately. Previous discussions shows that pin attachment isn't equivalent to suspension one and I already adapted the document for that as I remember. Shackle insulators and pin insulators are particular situations for shackle and pin attachments. I should provide more example without insulators for that. To me this is also shackle attachment : http://aac-publications.s3.amazonaws.com/anam-13201213050-1424994510.png > *A**s I wrote you in our personal mail exchange I have the feeling that > you are trying to map "concepts", not "things", through generalization: the > Platonic idea of a line attachment in this case.* > > You're doing the same in your current proposal about "substations" > (*https://wiki.openstreetmap.org/wiki/Proposed_features/Substation_functions > <https://wiki.openstreetmap.org/wiki/Proposed_features/Substation_functions>*), > where you want to generalize the concept of "substation" and apply it to > both the domain of power distribution (power) and fluid distributions > (pipeline). > > That's profoundly wrong in my opinion and I strongly feel that this should > stop: we are not here "to put order in the universe" and categorize a and > "name things" (*I'm an atheist, so I'm not much informed about this > things, but I seems to remember that the Bible talks about that...*), we > are here to map useful information about things. > Could you elaborate on why is this wrong please? I agree on concepts vs things (while I consider things as a particular kind of concepts) but the point isn't to put order in the universe, just share concepts and reuse established works. OSM is also known through this. All the best François
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