Cambrian ERTMS - Loss of TSR Data (20/10/2017)

[whole diary]

[eXPassenger]

One thing I find slightly surprising is that the temporary speed restriction had been in place for 3 years because of level crossing sighting. I wonder at what point a TSR^▸ (Temporary Speed Restriction) becomes a PSR^▸ (Permanent Speed Restriction), and is there any plan to address the issue.

Thats a very good question.  Probably the problem here is that the Cambrian ERTMS^▸ (European Rail Traffic Management System.) system is quite bespoke and there is little, if any, technical support for getting software changes made.  Just my personal thoughts.

Surely a change from a TSR to a PSR would be a change in the operational data.  It would be horrendous programming practice to hard code this type of information.

[SandTEngineer]

One thing I find slightly surprising is that the temporary speed restriction had been in place for 3 years because of level crossing sighting. I wonder at what point a TSR^▸ (Temporary Speed Restriction) becomes a PSR^▸ (Permanent Speed Restriction), and is there any plan to address the issue.

Thats a very good question.  Probably the problem here is that the Cambrian ERTMS^▸ (European Rail Traffic Management System.) system is quite bespoke and there is little, if any, technical support for getting software changes made.  Just my personal thoughts.

Surely a change from a TSR to a PSR would be a change in the operational data.  It would be horrendous programming practice to hard code this type of information.

I agree that imposing a TSR and removing same would be 'Operational Data' but making it permanent would require the system software to be permanently altered (well, thats my limited understanding of the capabilities of the ERTMS system).

[eXPassenger]

One thing I find slightly surprising is that the temporary speed restriction had been in place for 3 years because of level crossing sighting. I wonder at what point a TSR^▸ (Temporary Speed Restriction) becomes a PSR^▸ (Permanent Speed Restriction), and is there any plan to address the issue.

Thats a very good question.  Probably the problem here is that the Cambrian ERTMS^▸ (European Rail Traffic Management System.) system is quite bespoke and there is little, if any, technical support for getting software changes made.  Just my personal thoughts.

Surely a change from a TSR to a PSR would be a change in the operational data.  It would be horrendous programming practice to hard code this type of information.

I agree that imposing a TSR and removing same would be 'Operational Data' but making it permanent would require the system software to be permanently altered (well, thats my limited understanding of the capabilities of the ERTMS system).

As a retired IT Director that horrifies me.  All the operational data should be in a database with strict controls and auditing of changes.  The programs should then apply that data.  By analogy your Sat Nav system is not re-issued when a speed limit changes, there is just an updated map file.

[Worcester_Passenger]

As a retired IT Director that horrifies me.  All the operational data should be in a database with strict controls and auditing of changes.  The programs should then apply that data.  By analogy your Sat Nav system is not re-issued when a speed limit changes, there is just an updated map file.

Agree completely.

[stuving]

As a retired IT Director that horrifies me.  All the operational data should be in a database with strict controls and auditing of changes.  The programs should then apply that data.  By analogy your Sat Nav system is not re-issued when a speed limit changes, there is just an updated map file.

Agree completely.

What the report describes for PSRs^▸ (Permanent Speed Restriction) is that they are kept in non-volatile memory, but it doesn't say what process is involved in changing that. It could be similar to flashing the BIOS in a PC - take RBC^‡(resolve) out of service, load loader and data, burn into NVM, restart RBC processor and run read-back mode to check data, restart in service - something like that.

For the first user of the equipment, on the LGV^▸ (Large Goods Vehicle) to Alsace, TSRs^▸ (Temporary Speed Restriction) were also held in NVM, because they were managed by track maintenance staff not signallers. The report does not say whether this was the same memory as for PSRs, or another one, nor whether there were different change procedures. I imagine the work methods for this task will be those familiar to signalling technicians, which might not be how IT would approach it.