A few months ago we learned just how fragile our train system is, even after re signalling it when the the whole system was brought to its knees due to a faulty power supply that that fed the desk from which the Auckland network is managed from. Last night something similar happened once again with some sort of signal fault once again taking out the entire Auckland network for a period of time during the rush hour.
Auckland train services are starting to move again after hundreds of Auckland train commuters were left stranded at Britomart Station.
An announcement was made about 6.25pm that no trains were running due to a signal failure in Auckland. The failure was originally reported as being in Wellington.
By 7pm, Auckland Transport said signals were now operational, but passengers should still expect “significant delays”.
It was originally reported as being another fault in Wellington however Kiwirail is now saying the fault occurred in Auckland. Regardless of where the fault originated it is pretty shocking that we have now had two faults that have taken out the entire network at such a critical time, especially considering the system is virtually brand new. This kind of problem is clearly not a good look and just last month at the Auckland Transport board meeting staff promised that we wouldn’t see any repeat. My guess is there will be some sort of investigation that occurs where there are a whole pile of fingers pointed and some small changes will be made but once again no one will really be held accountable.
In may ways it is a real shame as it contributes to taking the gloss off what is meant to be a pretty high quality and advanced system even compared to many other places around world. What has been installed is a European Train Control System Level 1 (ETCS Level 1) although some parts of it aren’t even active yet and are waiting on the arrival of our new trains to take advantage of the new features. One thing that has gone live recently is an automatic signalling where a computer controls most of the mundane tasks of running the network freeing up staff to deal with the more complex issues. It is the first time that the system has been used in New Zealand and here is a bit of an explanation as to how it works:
Automatic Route Setting works within the following way: a computer database holds the master timetable for the Auckland network. The data includes train numbers, train types, all stop times, platform allocations and routes.
Operational Planners then programme preset “commands” and “check conditions” to set points and clear signals.
These commands are saved as “triggers” and associated to a particular location on the track. When a train is detected at that track location, the computer identifies the train number, and therefore its route.
The logic then looks at the “check conditions” (such as making sure other trains have passed or the train crew have operated a train-ready device) and if they comply, it will clear the relevant signals for the correct path. All this happens in seconds.
If the conditions for a particular command are not met, then the system will retry for up to five minutes before alerting the Train Controller that the route will not clear.
Over time, more and more trigger locations will be set throughout the network.
For example, a southbound train arriving at Ellerslie will trigger a command to set the route at Penrose to go to or from Westfield. Those signals will be set by the computer if it sees no other trains in the way.
If there is another train present, the train will trigger another request when it reached a second trigger closer to Penrose Junction. If there is still another train in the way, that command will keep trying until the track is
free or five minutes expires.
This means the train is getting the correct route as quickly as possible after the track is free.