Toronto Crosstown LRT | ?m | ?s | Metrolinx | Arcadis

[Coolibop]

Those were the original software problems going back a year or so, and well before everything was completed enough to allow TTC access for training.

This new problem is one that had not been seen before, and was deemed to be safety-critical.

Dan

I understand. I was just trying to convey that we'd all be more forgiving of it if the construction portion went smoothly...

 

[jordanmkasla2009]

For what possible reason would they need ATP for the dedicated sections of ION? At the speeds and frequencies they run, surely a meeting between trains isn't very likely? This isn't a subway service running every 2 minutes...

The signalling system was designed for the eventuality of 5 minute frequency intervals with doubled trains. While is not needed in the on-street portion between south of Waterloo Public Square/Willis Way and north of Mill Stations because of the speeds of 50 km/h or lower and transit signals at intersections the other sections do need to have ATP in order to allow multiple trains I’m each direction to enter these sections without needing to have track warrants. The off-street sections permit speeds of 70 km/h in sections and so they do need a signalling system to protect against collisions between trains

 

[IRT_BMT_IND]

For what possible reason would they need ATP for the dedicated sections of ION? At the speeds and frequencies they run, surely a meeting between trains isn't very likely? This isn't a subway service running every 2 minutes...

I think for a new build situation there is little or no difference in cost these days between a conventional block signal system with lineside signals and train stops and a more advanced signalling system with moving blocks (it might even be cheaper due to less lineside hardware). So I guess from a planning perspective there's little downside with going with the more advanced system even if you will never run trains frequently enough to take advantage of all its capabilities.

 

[rankman]

The line runs automated in its grade-separated right-of-way underground/elevated (Automatic Train Operation or ATO), and once it emerges at Laird, it switches to manual control since it runs on street (Automatic Train Protection or ATP). Transitioning between the two systems on one line mid-service I believe is somewhat unconventional and is probably behind some of the headaches.

Edmonton experienced similar problems and delays with its Metro LRT Line. The downtown portion is double lined onto the existing Capital Line tracks which uses a fixed block control system. Thales which wrote the train control software claimed they could integrate the Metro Line’s moving block control system with the older fixed block system. The software was ultimately unable to deliver the desired headways and was replaced by software from Alstom.