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An open letter to QR

Started by p858snake, May 15, 2012, 06:41:41 AM

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STB

A very detailed response about the technicalities of the cause of the signal fault has just been posted on the Queensland Rail Facebook page.

Quote
Again, thank you for your concerns about our City network, and, in particular, the Cleveland line.

To answer your question regarding the cancellation and late running of services on the Cleveland line on Monday, the following may assist. Due to time constraints we don't typically seek this level of detail but we felt your questions were important and the followers of this post would appreciate the detailed and technical response you were seeking.

The issues were due to a signalling fault at Thorneside, and this affected services between Thorneside and Cleveland. The cause of the signal fault was due to the failure of a relay, and, as a result, the signalling set all signals to red. This is because our system fails 'safe', which is essential to the safe running of our network. Similarly, if there is an issue with a boom gate it fails safe, ie it comes down, so that it is safe until repaired.

Signal relays are electrically controlled switches that are used to provide information about the condition of the signalling asset. The information provided includes details such as the occupancy of the track, the colour of the signal aspects presently displayed and a host of other information. Signal relays are manufactured to a fail-safe design, utilising an international standard for their operation. Relay contacts are manufactured from silver and carbon to preclude welding (which would be an unsafe failure).

In this particular instance the relay that failed was used to provide information about the state of the bi-directional (two way) track between Thorneside and Birkdale. The contacts used for this information had become high resistance (through carbonisation or tarnishing, as occasionally occurs with all relays) forcing the signalling system to respond by failing to a safe mode, preventing the normal clearing of signal routes for trains and thereby preventing any possibility of collision.

Queensland Rail has many thousands of signal relays in service, all providing very high reliability. They do not contain any field serviceable parts and are only reconditioned. They are therefore not generally considered a maintainable item, and are replaced either on failure or at end of service life.
Worldwide experience has been that invasive early removal for predictive testing has introduced more failures due to disturbance of the relay base contacts (where they plug in) than are prevented by early detection of high resistance internal contacts.

Relays are just one part of a very complex system which makes up our City network. There are hundreds of points (which enable trains to be guided from one track to another), a few thousand signals, and our overhead electric traction system which covers a couple of hundred kilometres. We also have a train fleet of over 200 units, which require regular maintenance and safety checks.

Speaking of maintenance, in 2011 we introduced the Scheduled Corridor Access Scheme (SCAS), which helps us to reduce the number of ad hoc closures throughout the network. Each SCAS closure is planned and managed as an integrated shutdown, combining all construction and maintenance works. Under this program, the SEQ network is divided into seven zones and closures are scheduled in each zone four times a year on weekends to avoid affecting peak hour services on weekdays. We do this to improve the reliability of our network, but not at the expense of customers who rely on us to transport them on the busiest days of the week. We can't keep everyone happy with these closures (you can see other threads on our page calling for less closures), but we do our best to schedule them so they don't clash with major events on the calendar. A well maintained line will help to improve the reliability of the network.

Sometimes, though, as with the case of what happened on Monday, we can't prevent every single problem which occurs on the network. When an issue like a relay failure occurs, we try to get the problem fixed as soon as possible, including having teams in the right locations with the right equipment to do so. Our team in the control centre does its level best to ensure as many trains can get through during disruptions as possible, but safety is always the foremost consideration.

People who work at Queensland Rail understand the frustration our customers have when trains are delayed or cancelled, as often we are affected, as well. For commuters who choose to travel by car, there can be unforseen circumstances which affect their journey. Even the most well-maintained vehicle can have engine problems, flat tyres, or even be involved in a collision. People travelling by car can get caught in congestion, which, of course, isn't their fault, but it's a part of the daily commute. Train networks are the same, in that only a certain number of trains can get through certain areas at the one time in a safe manner.

While failures on our network can be due to Queensland Rail's infrastructure, there are occasions when delays occur due to issues which are completely out of our control. If there is a medical emergency or an incident require the Queensland Police Service to attend, then the safety of our staff, customers and emergency services is of the highest priority. Sometimes Mother Nature may be the cause of delays on the network, but that is something we have to live with and work around.

Stefan, you are correct that the responses we put out to customers' feedback are honest and follow a logical sequence of decisions and actions in order to minimise the inconvenience to Queensland Rail customers. As we have stated earlier, not every problem on our network can be prevented through maintenance, so when an issue occurs, the best way to deal with it is to come up with a solution which gets our customers moving as quickly as possible. We are always looking at ways to improve our communication when incidents occur, as we know our customers need to be informed when their services will resume.

As much as we are looking at ways of improving the maintenance of our network, we also feel it is important to make sure our customers have a comfortable journey when they are on trains. Quiet Carriages and our Train Etiquette program are just two initiatives which, from the feedback we've received, have assisted in making journeys on our network more comfortable for the majority of our customers. We have mobile presentation attendants working their way through our fleet of trains to ensure they are kept in a clean and presentable condition. I imagine you would prefer we didn't neglect areas like cleanliness, in the same way we don't feel it's appropriate to neglect the comfort of our customers on board our trains.

We know there are ways we can improve our service and feedback from our customers is always welcome. We only ever ask that customers understand it is a very large and complex network we run, and, much like every other form of transport, it is not perfect.

We wish you safe and smooth journeys on the Cleveland line in future, and rest assured, we will be doing everything in our power to ensure our lines in that area run as reliably as possible.

:lo :is-

Fares_Fair

WOW  :-w

What a great and finely detailed response by QR  :-t
Regards,
Fares_Fair


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