Wednesday, November 6, 2019

What's the LRT's problem?

At today's meeting of the Ottawa Transit Commission the OTrain's bosses spilled the beans on what's ailing the Confederation Line, or at least tried to. I didn't attend the meeting, but did listen in via live-streaming. I was especially interested in what the bosses had to say about what was causing all the problems on the Confederation Line.

Look, software is at the core of the light rail system as it is in just about every other system in our world. After listening to the technical briefing on what the problems are with the Confederation Line it sounded like the common factor is software systems, and the interactions of those software systems with other systems in the Confederation Line. Also, it sounded like the current problems only surfaced once the parallel bus lines were closed down and the Confederation Line went to full-scale operations. Maybe classic scaling problems were kicking in?

The technical problems were isolated to 4 areas: the Train Control Monitoring System (TCMS), the Vehicle On Board Controller (VOBC), the doors, and the switches. It sounds like the city has demanded an all-hands-on-deck approach from the Rideau Transit Group (RTG), who maintains the system, to fix those systems. Some problems have been lessened, but the overall system is far from being all fixed up, and the OCTranspo bosses were hard-over on socializing to all present that things aren't at normal, and it could be a long while before they are.

For TCMS, root causes have not yet been found, and various operational work-arounds are being put in place.

For VOBC, there are 2 of these controllers on a train, if both have issues, the train is taken out of service. No details were given on what's wrong with this system.

For doors, problems were identified as riders 'interacting' with the doors (aka, holding them open I guess), and in the door safety features. The doors have obstruction processing software, and it sounded like there were 9 issues with it. Some improvements have been made, but they're not completely fixed. The bosses emphasized that door problems are common on LRT systems around the world. I guess they meant this as some indication of normalcy, but I interpret it as a systemic issue with modern LRTs, which is not good.

For switches, one of the problems was with covers that were installed for winter operation, and they had to be removed - I'm not sure what they're going to do when winter actually arrives, which weather predictions say may happen tomorrow with the first snowfall. One work-around is rather old fashioned, and will be familiar to model railroaders: have a technician - basically what we'd call a switchman - stationed at each cross-over, where the switches are located, during rush hours to be on top of problems when they occur.

The bosses took great pains to tell the audience that the actual uptime and operational performance of the Confederation Line is quite good in comparison to other systems around the world. The audience was also told that problems are normal during system startup. Interesting, but cold comfort to riders who actually bear the consequences of these malfunctioning systems.

In a system like this you've got sub-systems everywhere, on the trains, signalling, monitoring, train control, people, and so on, and these systems are interacting with each other. These aren't old school LRTs and streetcars that rely on people and protocols that people use to interact with each other in order to make the system work. For example, with the Confederation Line, every station was designed to not need any staff. So, one of the work-arounds, to at least improve customer relations during times of delays, is to hire staff to man the stations.

The upshot seems to be lots of work-arounds are being put in place to minimize rider impacts as delays continue to occur on the Confederation Line as RTG and OCTranspo work to fix the technical problems.

There was lots of other discussion and presentation on operational improvements and work-arounds. But, overall, it's one of those situations where only time will tell how all this pans out. I hope these are just the teething pains of a new system and not indicative of deeper systemic problems.

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