Re: Sydney's train network grinds to halt due to communications issue - ABC News
  peterm...

COntroller duplication, update one and leave the standby on the previous
software version and fail over to the older version.


On Thursday, 9 March 2023 at 09:01:12 UTC+11 Matthew Geier wrote:

> On Wed, 8 Mar 2023 at 17:39, Tony Galloway a...@...> wrote:

>

>> Wasn’t that long ago there was no 2-way radio, digital or otherwise, and

>> trains ran just fine.

>>

>> Now everything stops without it - what a joke.

>>

>> Must be that wonderful ever onwards “march of progress” that makes

>> everything work so much better.

>>

>> Someone (a group of managers more like it) has written the operation of

> the train radio system into the SMS and made it a 'vital' system so if that

> system is not operational, they are not meeting all requirements for 'safe

> operation'.

> Never mind the railways ran for 100 years without radios and fancy digital

> trunked comms systems.

>

> Seems the concept of a driver looking out the front window and observing

> the status of the signal lamps beside the track is no longer considered

> 'safe'.

> There was no suggestion that interlockings had failed, or the actual train

> control systems were down, what they lost was the network-wide GSM-R-based

> train radio system. They couldn't talk between operations control and

> trains in the field.

>

> I observed the Cronulla branch being operated as a shuttle during the

> outage, showing some initiative on the part of Sutherland station master to

> take local control of the Cronulla branch. I've seen reports that Blacktown

> did the same for the Richmond branch.

> I just hope the relevant staff now don't get reprimanded for 'unsafe

> operations' for showing some initiative to keep things running. Not all

> station staff are safe working qualified anymore - I do wonder how they

> will formally withdraw the qualifications from SMs that still hold safe

> working qualifications, preventing any further local control initiative

> taking on their part again.

>

> They did a software update of the train radio controllers on the weekend.

> I suspect that update wasn't tested under a full load of a busy system - or

> tested long enough - the new software having a 'slow leak', so that it only

> works for a few days - then falls over.

> Vital systems should have redundant controllers with the software of each

> written by different teams so that the two don't have the same bugs. But

> that's expensive - doing all your R&D twice.

>

>