[Tagging] Feature Proposal - RFC - 3rd and 4th rail

Michael Reichert osm-ml at michreichert.de
Tue Jun 9 21:12:14 UTC 2020

Hi Colin,

Am 09/06/2020 um 15.36 schrieb Colin Smale:
> Great idea. Not sure about using "3rd" and "4th" though - it's a bit
> tightly coupled to the English language and possibly prone to error.
> Wouldn't "3rail" and "4rail" fit the bill? 
> Actually, as electrified=rail is so widely used at present, how about
> making that explicitly "3rd rail" and introducing a new value for the
> 4-rail system?

I am in favour of splitting "rail" into two new values for systems with
a 3rd and a 4th rail (no matter how it is spelled exactly in the value).
Currently all 3rd rail and 4th rail systems are tagged as "rail", aren't
they? If we followed your suggestion, "rail" would mean "3rd rail or 4th
rail system" and "4th rail" would mean "guaranteed 4th rail system".
It's a bit like "yes" is a incomplete value for electrified=* which
should be replaced by a more precise value like contact_line if one
knows it.

> How would we indicate the voltage/frequency of the two rails
> independently? On the London Underground it's mostly +420/-210 (these
> days +500/-250) but there are some areas where +750/0 is used
> (Richmond-Gunnersbury for example). 

Is voltage=* used on that lines as the difference between positive and
negative, i.e. voltage = 750 = 500 - (-250)?

> While we are at it, could we take the opportunity to find a way to
> represent three-phase dual-overhead systems (Switzerland etc) as well?
For readers being confused: Gornergratbahn in Zermatt uses it.

Best regards


-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: OpenPGP digital signature
URL: <http://lists.openstreetmap.org/pipermail/tagging/attachments/20200609/68576be6/attachment.sig>

More information about the Tagging mailing list