Cancelled train displayed as on time at West Ruislip

[Route115?]

I was hoping to catch the 08:59 West Ruislip to Marylebone (2H18) last Tuesday, 19th Nov and checked the National Rail website which said that it was on time, as did the indicator on West Ruislip Platform 4. I suspected that it might be late as there was no train in the platform and green signal on the through line, but this can happen when a train is passed by a fast train. However, once the fast train (5H14, a VST) has passed,2H18 just disappeared and the next train 68 minutes later (this is zone 6) appeared. Luckily there was also the Central Line for me, though not much good for intermediate station. An examination of RTT showed that the train was indeed cancelled together with the 2R14 from MYB which was terminated short at South Ruislip at around 08:40. My question is why didn't the departure board (and National Rail website) show it as cancelled? Was this because of the late part-termination of the previous service and a manual intervention would have been required? Any thoughts?

 

[Stephen42]

The 2H18 service you mention and 2R14 were both cancelled on Network Rail's TRUST (that drives RTT cancellation messages) at 9am roughly 20 minutes after the problem occurred. Often staff will run through a checklist or similar trying to get the unit moving before a decision is taken to cancel. If the National Rail system was updated at a similar time to the Network Rail one then it would have been shortly after the scheduled departure.

The underlying National Rail data doesn't easily provide a cancelled at time which makes retaining a cancelled service for a short period after its cancellation difficult so nearly all systems it will disappear from the list if the scheduled time was in the past. Any cancellations for a future time will remain on the board until the time passes. Audio announcements on stations are usually triggered relative to the scheduled departure time, that won't happen if cancelled after scheduled departure time as it's gone from the list.