Passenger Train Allocation - Order of vehicles

[Juhani Pirttilahti]

Hi all,

First of all I just wanted to say how great this dataset is. It is an excellent addition to the open data in the UK. Thanks to everyone involved.

TAP/TSI messages are a huge contrast to Sweden where all details about consists are offered in a simple free-text field:

E.g. "Vagnsordning Lok-[9-8-7]-6-5-4-3-2"

Finland has its own proprietary JSON format, and Norway uses SIRI-SM XML messages with a TrainFormation extension schema.

Anyway, I'm not always sure if I interpret the data correctly. In particular, the order of vehicles in consist.

Ordering logic I'm using is currently like this (in Postgresql):

ORDER BY

AllocationOriginDateTime,

ResourcePosition,

CASE WHEN Reversed='Y' THEN ResourceGroupPosition END DESC,

CASE WHEN Reversed='N' THEN ResourceGroupPosition END ASC

Looking at the 23:45 Paddington–Penzance 1C50, the result of the query is:

<- 57301 - 10563 - 10596 - 10534 - 10589 - 10616 - 10219 - 12142 - 17173 - 57312

Rear loco leaves them at Reading. This seems correct.

Then, looking at the 17:22 Cardiff Central–Holyhead 1W96, there appears to be a DVT in a very odd place, in between vehicles, while typically DVTs should be at the either end.

This is the order I've interpreted for 1W96 leaving Cardiff Central:

<- 12434 - 12310 - 12211 - 82201 - 11319 - 10318 - 67022

Then the train changes direction at Chester, the next leg has Reversed=Y, and the consist is reversed to reflect that. That seems to be correctly put in.

I don't remember which way round the loco is when the train leaves Cardiff. Last time I was on that service it was all Mk3s. It would be helpful to know. :)

Also, noted that TfW's Coach letters look weird. For this train: C - F - B - P - L - H - (Cl67). ScotRail's HST's have Coach letters that are always obviously wrong - maybe the letters have not been updated for a while?

Kind Regards,

Juhani

[Tom Cairns]

Hi Juhani

For a lot of this data I take it with a lot of caution. For most operators the precise order of vehicles may not be front to back, and vice versa, within individual sets/units. The ordering of the vehicles within the sets/units may not be accurate either as you have seen.

On RTT we just override the coach letters almost always to the correct ones (where we feel it is relevant or necessary) as the data held within R2 which feeds a lot of the coach data is nonsense. For the XC HSTs way back in the day some of the letters were what they were lettered as with their previous operators!

In essence, the vehicles contained within a unit/set should be right, but the ordering and metadata could well be wrong. The industry does have other data streams that could be used for orientation reasons but every time I’ve tried to research that path I’ve been told I don’t need it :-)

Tom

--
You received this message because you are subscribed to the Google Groups "A gathering place for the Open Rail Data community" group.
To unsubscribe from this group and stop receiving emails from it, send an email to openraildata-t...@googlegroups.com.
To view this discussion, visit https://groups.google.com/d/msgid/openraildata-talk/a685c31a-45c2-4215-b03d-ea71e6640843n%40googlegroups.com.

[Juhani Pirttilahti]

Hi Tom

Your point is spot on and well explained. Still I bet there must be public interest for correct data! Public facing information should always be as correct as technically possible. Overriding existing data must be avoided, in my opinion, but I do see how it is necessary.

I tried to search if this has been discussed before, but I don't think so. Personally I think there should be some quite direct way for us (developers) to communicate to the suppliers/TOCs that something doesn't look quite right. I don't know how the customer services treat the technical stuff like this. I would imagine at least some of the TOCs would be interested in having correct information in all channels. There are ways to improve daily processes, internal memos, training, etc...

It is frustrating to be told no, I hear you, been there done that. Sometimes the answers are just plain weird, or I get a feeling that I'm too little to ask. I'm going a little off topic, I've asked for vehicle numbers in Finland but been repeatedly told there are commercial interests preventing the disclosure of vehicle number data a public body holds in their databases. Someone could work out the diagrams... But for commuter trains unit numbers are now public because the public transport authority purchasing the commuter traffic, Helsinki Region Transport, made a special request.

Juhani