| Re: joined continue: "Platforms and ramps for railML 2.2" and "Haltetafel / stop post" [message #296 is a reply to message #294] |
Thu, 05 April 2012 02:09   |
Dirk Bräuer
Messages: 311
Registered: August 2008
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Senior Member |
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> Still I do not fully understand the idea behind the additional
> conditions "axle count", "wagon count" and "verbal remark" (cp. post in
> subject "Haltetafel / stop post").
These refer to the small white additional signs below the normal black
German H-Tafel. It is necessary to have these additional signs if there
ist more than one stop post at one station track per direction. Nowadays,
there is always a (maximum) length of train written at these additional
signs. In former times it was more common to write an axle count. May be
you have seen a writing like "Rz 48x" below a H-Tafel which means "for
passenger trains with up to 48 axles".
It should not be conditions but simple properties.
> The sign code is important, but I would use the parameter "code" for it,
> which already exists for any ocsElement.
Since 'code' is an inherited attribute, it does naturally not rely to any
special property of a stop post. It should be saved for more general
usage, like an external primary key or so. For instance, if you describe a
point (Weiche) you should use 'code' for the point number (Weichennummer)
which is the external primary key. You should not write the rule book
number of the point's signal into 'code'.
> That is an interesting idea. The question is if there physically exists
> a "substitute" for the stop post, which can be used for stopping a
> train. Since we always talk about infrastructure, I'd rather see a
> physical element providing the function of a stop post instead of
> defining virtual elements. However, we need to analyse this problem.
Even if there would be a substitute it would be useless in this context.
My explanation was "what shall the <trainPart> in RailML do?". I assume
that there will be a possibility for a <trainPart> to reference a stop
post in future - like a <trainPart>.stopPostRef attribute. I assume that
you can only fill in references to stop posts - not to any other
infrastructure elements. That's why I think it is necessary to have
virtual stop posts.
Please, RailML is not a database for bureaucracy. It is functional and for
data exchange. So please do think functional.
What do you want to tell me with "we need to analyse this problem"?
There are virtual stop posts with and without "substitutes". A substitute
may be a Ra11 or So5/Ne1 in Germany. Often there is no stop post because
there is a starter signal directly at the end of the platform. You can
decide for yourself if a starter signal is a substitute for a stop post.
But in many cases I know there is simply nothing but the end of a
platform. I can send pictures for all these examples but I think we all
know them.
For instance, there are normally no stop posts in stations like Leipzig
Hbf. (Have you ever seen a stop post at the platform tracks of Leipzig
Hbf.?) I assume that there will be a possibility to define the relation of
a train to the platform by referencing a stop post (e. g. train stands
with its front at the end of the platform or with its rear at the
beginning of the platform or with its middle at the middle of the
platform). I think that it should be possible to define these relations
also in Leipzig Hbf. That's why I think we should allow virtual stop
posts. These relations are essential for run time calculation if you have
a MU of 35 m length at a 400 m platform with permitted speed of 40 km/h...
Enough arguing. There is a demand and so there should be a solution.
>> The reason for "PassengerTrains" and "AllTrains" is: In Germany normally
>> a H-Tafel is valid for passenger trains only except if there is no
>> starter signal in the track where it is valid for all trains.
>
> Another important idea that you are bringing up here. For clarification
> we have to ask ourselves whether we in fact talk about a combination of
> two different signs/signals just at the same position along the track or
> about a certain feature of a stop post, which cannot be found in a
> separate context.
There are no two different signs at the same location. You have these "all
train stop posts" also in other countries. I think they are a kind of
normal, typical for railways, natural. For instance I think at the big
markers 'Stop - obtain token to proceed...' with the big red splash at
RETB lines.
Dirk.
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