Another timetable?

I'm hoping that this question will get me an answer to a question which has been bothering me for a while...

There's a public timetable, but is there an operational schedule as well?

The group I travel with in the morning are amused to think that I suspect that there are two timetables in operation at the same time, but I figure there must be because those involved in operating the trains must have something in the system which is based on the public timetable but which also:

1. Brings together the different passenger and freight services operated by London Midland, Virgin Trains, London Overground, ScotRail Caledonian, EW&S, etc
2. Covers empty stock movements
3. Defines whether a train will normally run on the fast or slow line (and where they will switch over if appropriate)
4. Specifies which platforms will be used at which stations

What has prompted this question is that the existence of what might be described as a parallel timetable is the only explanation I can think of for a change that we've had with the 07:00 from Bletchley to London Euston.

Prior to the last timetable change in May, the 07:00 ex-Bletchley crossed over onto the fast line at Ledburn Junction (south of Leighton Buzzard) and ran at a fairly constant speed non-stop to Euston, arriving on platform 17, usually within a minute or two of the scheduled ETA, 07:43.

After the last timetable change the train was switched to Euston platform 11 where it invariably got in 5-6 minutes early (see Timetable flab?)

Two weeks ago things changed.  The train still comes into Euston on platform 11 but it is back to arriving around 07:43.  The extra journey time seems to be down to a delay around Ledburn Junction where we seem to arrive at about the same time as a southbound Virgin service.  The impact of this is either:

• We slow then sit and wait for that train to pass before crossing over from the slow line to the fast.
• The speed drops off at Ledburn and we continue down the slow line.  We presumably have the all-stops service (Bletchley depart 07:53) and/or the Tring shuttle (Euston arrive 07:38) in front of us, and aren't able to get clear until we cross over to the fast between Berkhampsted and Hemel Hempstead

If my theory about an operational schedule running in parallel to the public timetable is correct then I reckon that the former was changed a couple of weeks ago.  The Virgin service that passes us at Ledburn is either running later or earlier than before, resulting in a delay to our own train.

If there's anyone reading this who knows how this all works then I would really appreciate it if you could let me know whether the second (operating) timetable exists (and if it does then a) how often it gets updated and b) whether it is available for public access). 

Please email eustoncommuter@gmail.com or submit a comment below.

Many thanks.


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