FK270673 at fantasymail.de FK270673 at fantasymail.de
Sun Jan 20 17:03:54 GMT 2013

```As requested, I would like to give an explaining statement on those Canadian powerlines which I have edited so far. Personally, I was driven by the intention to achieve a similar standard of quality for all parts of the world, including Canada.

Until 2012, very small pieces of powerline have been gradually imported from CANVEC database. They did not have any towers. They had intersections with other powerlines which would immediately break electrical devices in reality.

In 2012, I have merged and realigned some Canadian powerlines according to their logical layout. As one powerline usually connects two substations, it does not make sense to split it into many small pieces. A typical double-circuit powerline (6 cables) usually has three segments: two feeders at the first substation, one long trunk line between both substations and two feeders at the other substation. A single-circuit powerline (3 cables), which is more vulnerable to outages, directly connects two substations without any feeders. Each circuit has its own entrance to the substation in order to enable a quick response in case of breakdown. Circuits are usually arranged according to their voltage, e.g. 230kV circuits on the West side and 120kV circuits on the East side. Within a substation, one or several transformers are connecting these circuits.

How can you distinguish single and double circuits? The following photo shows a typical powerline in Toronto, Canada:
http://wiki.openstreetmap.org/wiki/File:Toronto_Power_Line_L14W_Tower_39.JPG
This is a double-circuit powerline: on the left (northern) side is circuit L14W, on the right (southern) side is circuit L13W. L indicates a powerline originating in Leaside Substation, W indicates a powerline arriving in Wiltshire Substation. 13 and 14 are line numbers. L13W;L14W ist the reference for the double circuit running through power tower number 39.  On the right side, you can see another single-power circuit (3 cables) called L 15W. All towers usually have subsequent numbers, however, within substations they may have additional letters like 37B. ref=37B would be the appropriate tag for this tower.

L13W, L14W and L15W are 115kV powerlines, as 230kV powerlines usually have numbers >200 and 500kV powerlines usually have numbers >500. This numbering scheme applies for Ontario only.

In Quebec, powerlines usually have a four-digit number where the first digit indicates the voltage. The following construction announcement displays the power network in Québec City:
http://www.hydroquebec.com/projets/pdf/charlesbourg_is.pdf
You can see single-circuit 735kV powerlines, double-circuit 315kV powerlines and some single-circuit 69kV powerlines. Le Poste des Laurentides has a northern section for 735kV powerlines, a central section for 315kV powerlines and a southern section for 230kV powerlines. There is a small segment where a 230kV powerline (circuit #2369) and a 69kV powerline (circuit #757) are joint by sharing the same towers, so there is a short double-circuit segment. It would make sense to create a relation for those two powerlines

Each voltage was considered as an optimal solution in the year of construction: 69kV lines in 1910, 230kV lines in 1940, 735kV lines in 1970. Changing the voltage would require some billion-dollar investments, so power companies are trying to keep their electrical devices as long as possible for economic reasons. However, HydroQuebec is gradually going to replace its old 69kV powerlines with new, more powerful 230kV powerlines. For example, Poste Lemoilou, a new substation in Québec City, is scheduled to open soon. As you can see, construction announcements contain a lot of useful information that is worth being integrated into OSM.
http://www.hydroquebec.com/projects/limoilou.html
A single piece of powerline is easier to maintain in case of lifecycle update (e.g. decommission). However, I do not object to the reconstruction of merged powerline segments if you are willing to maintain them. You are invited to add or verify tags for Canadian powerlines which I have described above. Each substation has a label with its (bilingual) name, its address, its operator, and many more useful informations.
http://wiki.openstreetmap.org/wiki/File:Toronto_Gerrard_TS.jpg
Even substations of underground cables like Lakeshore Jarvis are labelled.
http://wiki.openstreetmap.org/wiki/File:Toronto_Lakeshore_Jarvis_TS.jpg

Yours, cordialement and with best regards,
FK270673, also known as mapper #42429

P.S.: Je prie les utilsateurs québecois de me pardonner une annonce anglophone même s'il concerne tout le Canada.

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