Actual Times for arrivals - sanity check!

[Miles Taylor]

Hi All,

I've recently started loading schedule and pPort from the FTP site into a database.  I am looking at yesterdays data (ssd='2016-03-06') and noticed that a huge number of actual arrival times are missing from calling points.  I see in the documentation that no value means not reported, but there are 35,000 missing!  I'm excluding OR and PP, just looking at IP and DT, of which there are 138,000 being a Sunday.

I've checked a handful against http://uktra.in/rtt/train/ (helpful to have somewhere to compare with, thanks!) which seem to match, but I'm still concerned I've messed up as so many are missing.

Can anyone confirm this is as expected?

Many thanks

Miles

[Peter Mount]

It's possible as not all points report any times.

One example from tonight is http://uktra.in/rtt/train/201603073321967 which I was on. You'll notice that from borough green there's no report until Maidstone east & them nothing until Ashford.

There's another 'oddity' if you look at Otford. It'll only ever show an arrival going coast bound, never a departure time.

I've always presumed is down to the signaling. It can only report if there's a berth just for the platform, which explains Otford as it can tell of the arrival. Also further down the line west & east malling have the same berth so no report is possible there.

I might be wrong but that's how I've taken that ever since I saw the same thing with the nr td feed in the past.

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[Miles Taylor]

Hi Peter,

Thanks for the quick response.

Yes, I see what you mean.

So this is down to the source of the information, there is no point me trying to use the web services as they'll show the same?

If this is the case how does the Public Performance Measure get calculated with missing actual information?

Thanks

Miles

[Peter Mount]

Ppm is always at the destination which is usually (always?) a reporting point. Also the official figures include any manual entries which aren't always entered immediately so we don't see them (not certain if the trust feed sees those when they are entered).

As for the Web services, I've not used them but I believe they should be the same as push port,  more so since the last release included extra fields that were in the push feed.

[Miles Taylor]

Hi Peter,

Ok, only the final destination counts for that metric.

This leads me to another thought, in the press recently there is talk about trains skipping stations so they reach their final destination on time...   so, using your example, how could I tell if West Malling was skipped.  I was thinking there would be a missing Actual Time, but it's always missing for that station!  

Or maybe if it was Otford that was skipped I'd get an arrival time anyway as it was passing through the point, whether or not it stopped, like a PP?

Thanks

m

[Peter Hicks]

Hi Miles

When a train 'skips' a station, it's almost always organised in advance.  If the scheduled activity (the 'call' activity) is cancelled on Darwin - either through manual input, or through a Tyrell message, then it'll show up as a cancellation at that location.  If the activity isn't cancelled in Darwin, then it might:

  * Be entered manually in TRUST (Network Rail's system) as a Fail To Stop (FTS), but no message is produced as it's a Delay Attribution message which isn't made public

  * Be reported by TRUST as a Fail To Stop depending on the berth offsets for the arrival and departure events for the location.  The way it works is complicated but robust, however TRUST can receive an arrival report and then a departure report with an actual time of earlier than the arrival report for some locations where there are signals before and after the station close to the platform

Peter

[Miles Taylor]

Hi Peter,

That's very helpful.  So an example being Selhurst on 201603013123371 which is the only cancelled IP so must be skipped even though it has an Actual arrival time. 

Many thanks for taking the time to explain.

m.

[Peter Mount]

Yes in theory that's meant they've skipped the station.

Looking at http://uktra.in/rtt/train/201603013123371the passes are also cancelled. Now I don't know that route but could they be it's been diverted?

[Robin Strutt]

Hi Peter

I'm trying to find an example of an FTS record in TRUST, do you know of any recent ones so I can take a look at how the delay attribution codes work in the cancellation messages? Or do you know which delay attribution codes are normally used in these circumstances?

Thanks, Robin. 

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