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?us...
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(a)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
>> Op 27 jun. 2020 om 18:36 heeft Björn Mahrt <bjoern.mahrt(a)gmx.de> het
volgende geschreven:
> 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