JJJWegdam,

Please excuse if I repeat things that you already know - nothing bad assumed here, but for the benefit of those who may not already.

I can definitely agree the "wye" term is a bit odd - it started in British English railroad terminology, and spread widely, but it's use does seem to be deprecated in industry the past 80-100 years in favor of better technical descriptions. It seems to hang on due to getting mixed with the wye junction configuration (and probably due to heavy use in model railroad terminology, which a good few of us got exposed to before later working on or around the real thing).

Its use in the real world (at least where I am familiar, North American) is not strictly restricted to symmetrical contraflexure turnouts. However, an "unequal wye" or contraflexure turnout is pretty uncommon here anyway, in large part for the reasons you listed ... there normally needs to be a pretty severe space constraint before it is used.

"Outer curved" (or usually "outside curved") is already in widespread use in industry here with a different use than you suggest - but it will be one of two possible configurations of similar-curved (both in same direction) turnout, the other being inside curved. Both curve the same direction, but a better configuration of point geometry is given to the main track, so there is a difference that will generally be visible only in person or on drawings, probably not on satellite. However, often inside/outside can be safely and accurately inferred on satellite just by context of the surrounding trackwork. Outside or inside will refer to the location of the diverging (non-main) track.

For the quickest example I can quickly lay my hands on, see the last page here: https://drive.google.com/file/d/1Bssg4CxDwqJLvFhrgv49-jTzquyCF-Sk/view?usp=d...

If we wanted best consistency with industry (who need clear terminology so are probably clearer than we are), we might want to try:

railway:switch=contraflexure replaces both wye and outside_curved, because our outside curved currently implies the opposite of how I see it used in industry.

railway:switch:curved would strictly apply to similar flexure turnouts, as used in industry; everything currently tagged railway:switch:curved=outside would actually need to be retagged railway:switch=contraflexure. For contraflexure, left/right direction still applies. The occasional equal contraflexure (formerly tagged wye) could either be assumed with lack of left/right, or explicitly tagged under direction; alternately, we could just keep "wye" for that one case as it is already effective shorthand for "equal contraflexure," and would reduce the resulting changes.

I think this would also address Bjorn's original concerns, but would also be a pretty major change that would require a good bit of discussion. It might be clearer due to being more consistent with industry, or might be judged not worth the effort; I don't have a strong opinion either way. On the other hand, if currently mapped switches are done consistently in the current scheme, the change could be automated correctly.

Chuck VA, USA

On Sun, Jun 28, 2020, 5:02 AM Jeroen Wegdam via Openrailwaymap < openrailwaymap@openrailwaymap.org> wrote:

Dear Björn,

In the Netherlands and Belgium, custom curved turnouts are very rare. There is one exception though: the symmetric turnout. This is simply a special case of the Außenbogenweiche you mention. The reason is standardisation; custom turnouts are a pain to replace swiftly.

From my perspective, it would have made sense to distinguish symmetric turnouts from random outer curve switch flavours. That would opt for railway:switch=wye separately tagged from railway:switch=outer_curved.

Internationally I now think it makes more sense to follow Björns approach. Ideally we would change railway:switch=wye to railway:switch=outer_curved. The name wye turnout is seems quite unusual to me.

Best regards, JJJWegdam Switch & Crossing specialist at ProRail, Netherlands

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Op 27 jun. 2020 om 18:36 heeft Björn Mahrt bjoern.mahrt@gmx.de het

volgende geschreven:

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Moin,

ich stolpere immer wieder über Bogenweichen, von denen im bisherigen Taggingschema nur die symmetrischen Außenbogenweichen berücksichtigt werden (railway:switch=wye). Ich würde gerne das Tagging dafür durch folgendes erweitern: 1.) railway:switch=wye eigentlich für alle Außenbogenweichen, da der genaue Radius eh nicht ermittelbar sein wird (und optisch geht es halt eh beides nach außen) 2.) railway:switch=inner_curved oder curved für Innenbogenweichen, die bisher bei den einfachen Weichen mit drinstanden.

Natürlich gibt es das Problem, dass eigentlich alle railway:switch=default überprüft werden müssten, ob sie nicht Innenbogenweichen sind, aber schadet wohl auch nicht. Die Definition muss ja nicht sofort geändert werden, es wäre ja lediglich eine genauere Spezifikation.

Gibt es da irgendwelche Meinungen oder Bedenken? Sonst würd ich das (demnächst) mal mit auf die ORM-Tagging-Seite übernehmen.

Viele Grüße Björn