Hi everyone, Last days, I've launched a little discussion about the difference between aerial and underground lines which this draft try to introduce: http://wiki.openstreetmap.org/wiki/Proposed_features/Power_transmission_refinement
You can find it on the discussion page. I know that someone there had already asked for the introduction of power=cable for underground lines but this seems to be like a little mistake. Let's try to know why. "Cable" is a term referring to physical conductors. Using this for referring to underground lines, even if they are insulated, would imply that we have only one conductor in all cases, which is wrong. At high voltages, when a line go underground you have the same technology as aerial ones : separate conductors for each live (AC lines) or for each directions (HVDC ones). Everyone on this list must be convinced into there's no physical difference between aerial parts and underground parts of lines sharing the same technology (AC/DC, voltage, etc). Pictures : http://www.infos-reseaux.com/photos/album/61-genie-civil-souterrain (63kV AC line in french streets) Moreover, power=cable would be useful to map the stuff inside of power sub stations. For an AC power station, each live of a line (which come together from outside) would follow different paths to the busbars used to route power through the grid. I don't see more suitable word to tag this cables which correspond to single lives. They would be part of power circuits relations used by routing modules. My basic proposal is to use power=line + location=underground instead of power=cable + location=underground. Because it would be difficult to make request with location=underground negation as for obtaining only plain aerial lines, we can use different power=* tag too for aerial and underground lines. With or without location=underground. It's hard to make a choice. What are the tagging expert's or proposal author's opinion? The goal is to obtain a well documented topology of power grids. It's important to use the right vocabulary even if it seems to be dumb or engineering stuff. Greetings, *François Lacombe* francois dot lacombe At telecom-bretagne dot eu http://www.infos-reseaux.com
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