And it's going to be opening next Tuesday - here's the announcement from GWR^▸ (Great Western Railway) - especially for anyone who feels they count as "media":

I'm not sure where that came from for Portway - did we have planning plans? But measured off Google Earth, it's 126m too. Turbos are close to the nominal 23m per carriage, plus couplings, so 5 cars (3+2) is about 118m, which will fit (either station). Obviously that assumes sensible car stop positions, which for Portishead depends on the end of the line (buffer stop) position, but you'd expect that to be OK.

Operationally, that always did look odd. The Turbo fleet is a mix of 3s and 2s, and we all know that what's available to pick from on a given day doesn't always match the standard train plan. With only 126m, if you've no 2-car units then it's a 3-car or nothing. But by the time Portishead opens, maybe the Turbo fleet won't be relevant any more ...

It wasn't "faulty" when written. The processing in Brussels adds extra interpolated waypoints to flight plans, and in this case added one at Deauville, which has the ID code DVL. It already had a waypoint at Devil's Lake (North Dakota), which also has ID code DVL. That was probably a mistake - there's loads of possible waypoints to pick. And, taken in sequence, they can be located 4000 miles apart and the ambiguity resolved. It was the rather simplistic processing in FPRSA-R that led to it being unusable. And that should not have been such a drama.

The CAA^» (Civil Aviation Authority - about)'s independent Review Panel for this incident has issued an interim report. This concentrates on how NATS and other organisations coped with the loss of the National Airspace System service (NAS). Obviously that aspect will get most of the media interest, including the bit where the panel note that "some relationships between aviation sector stakeholders appear to be adversarial."

However, it does tell us a little more about what caused the system to fail. There was an earlier preliminary report from NATS on this (and there is also a final report, seen by the panel but not yet signed off by NATS and issued). That explained that a duplicate waypoint ID in the flight plan caused the processing failure, but his new report illuminates that further.

The relevant system is FPRSA-R, which takes flight plans from the AMS-UK^▸ (United Kingdom) (Aeronautical Messaging Switch) in the European standard format (ADEXP), identifies and marks the entry and exit points to UK airspace, and converts them into a domestic format and transfers them to NAS. Both AMS-UK and NAS are trusted to keep flight plans safely and not lose them; FPRSA-R is not - it's purely processing.

That means FPRSA-R is allowed to just shut down if it's unhappy, provided the processing is suitably interlocked. Thus when a flight plan is read from the output queue of AMS-UK, it is not removed - just copied. Only after it has been processed and handed over to NAS, and it has been confirmed as accepted, is the AMS-UK queue allowed to delete that entry and offer the next flight plan to FPRSA-R.

Despite all this talk about safety-critical errors, this behaviour of FPRSA-R looks to me like an unhandled exception. The initial recovery action was to restart it, but it tried to process the same flight plan and so failed again. The AMS-UK output queue was stuck with the invalid plan as its leading item. When the makers' expert from Frequentis AG was eventually called in, their advice was to transfer this flight plan into a new, unconnected, queue; in effect to quarantine it. It could then be given to a human operator to see if it could be entered manually, or if not, why not. Restarting FPRSA-R then succeeded, though it was another hour before the system was running again.

We are told NATS have a fix to stop this happening again, but not what this is. I can think to two obvious fixes. The shutdown can be allowed to happen as before, but the operators are trained to recognise its dying message and do this quarantining manually and restart. Alternatively some of this can be automatic: the quarantine action quite easily, avoiding the shutdown of both FPRSA-R systems with more difficulty.

This new report gives an explanation of how FPRSA-R works, and how the duplicate waypoint IDs arise and are handled (though no doubt this is simplified). From that, it seems clear it's just not clever enough. There is enough information available resolve the duplicates, but it isn't used. And behind that, I think there is work going on internationally to get rid of the short IDs that cause the duplications, but it's exactly the kind of non-urgent task for which progress in the international aeronautical community is at best very, very, slow.

It's a cancelled train!

That may have been an official plan, though its source is unofficial. There is a more recent plan in a presentation of Mark Barry's from last year (he's an advisor on Cardiff Metro). I can't link to it, but it shows (at p45) two new tram-train platforms outside central station, partly on the current car park. The track then goes through Callaghan Square and joins the Cardiff Bay line.

That fits the words just released better:

But plans do seem to be still subject to change.

Of course your local banks may have all closed, or (like mine) no longer offer cash handling services.

I thought someone ought to offer a cash delivery and collection service by secure van, as a replacement. And it appears they do - at least one tier of companies below the Loomis and G4S level. But I guess that costs even more.

I may have commented before that, for an island nation, we don't seem very conscious of tides and how they vary. Tide forecasts and warnings have a very narrow audience. Obviously it's different in France ...

To say how big tides will be over a wide area you need a coefficient, used to scale up (or down) the average tide height at each place. I have seen different ones used here, so we do not appear to have a standard definition. There is (of course) a standard French one, with extreme values of 20 and 120. Next Monday or Tuesday this month's peak (at spring tide) will be 118 - not far short of the maximum. This is the highest tide for ten years, and that made it national TV news in France.

Local tides depend not just on the global and regional factors captured by a coefficient valid for the whole Atlantic and channel costs of France, but on all sorts of local ones too. So the tides at Sea Mills may not be the highest for ten years - but expect something of that order. 

I do rather like that bit - we all know how important it is to have both God and Mammon on your side when you are running a railway.

The "Access for all" programme is about upgrading station facilities; as that's infrastructure it all goes through Network Rail (though the money comes from the government).

The label for operational support is "Passenger Assist", which is a national scheme but implemented and publicised by TOCs^▸ (Train Operating Company) individually. GWR^▸ (Great Western Railway) describe theirs on their web site, and in the booklet "Making rail Accessible". The relevant bit of text says:

They are rather vague about what that might involve, no doubt because needs vary so much case by case and they prefer not to create a more specific "right".

That's a bit misleading; all three of the people who collectively drove the train are on trial. The reports are not using the same terminology as the BEA-TT report (based on SNCF's documents) either. Those three were the hands-on driver, a driver manager who told him what to do and when, and a Systra engineer who handed over the "script" to the other two and then was meant to monitor the trial and answer technical questions. 

Finally, with all the urgency we've come to expect of the French legal system, the trial of several bits of SNCF, including Systra, began today. Here from RFI:

Including the driver in this trial seems particularly harsh, given what he's been through and how responsibility was described in the report as lying mainly with others. No doubt there would have been others but they wel killed in the accident.

Mind you, I don't think (without thoroughly revising the subject) the points picked out in that piece are the key ones. They may of course be present in a much longer legal text.

True, if that is slope stabilisation work, it does not seem to fit even the track replacement work in the project. But then apart from the two staff recorded at Wokingham Station, the other scenes in the video are not related to the recent work. The level crossing being renewed is Mays crossing in Datchet, and the overhead view is of Wood Lane crossing at Isleworth - done ages ago.

For a resignalling project, it did seem a bit odd for 1 km of track replacement to be included. But replacing Wokingham Junction did make sense as resignalling, not just using the blockade for another job. It would not make sense to replace it and to do the motorisation as separate steps.

And while it's not obvious how to measure the single track length of a junction, that one is likely to come out as is over 800m. Then there are the two crossovers worked by ground frames, at Bracknell and Blackwater, which have been motorised - and may have been replaced in the process.

When I went to have a look on Monday (19th) afternoon, there was a guy with a video camera on a tripod. He turned out to be one of the Basingstoke signallers who does the level crossings! He was promising shorter barrier-down times, suggesting there was a new block, or least a distant signal, on the approach from Crowthorne (though I'm not convinced of that).

I would expect the ROC^▸ (Rail Operating Centre - a centralised location for railway signalling and train control operations for a specific route or region) to be quicker than a local signaller, resetting the route for the next train using the lever frame before crossing the box to press the button, especially with ARS^▸ (Automatic Route Setting). Crossings now have their own signaller, and I was surprised to see that they use a box with lights and switches per crossing, not a patch of a screen.

I didn't gather whether this video was for familiarisation and briefing purposes, or whether he was being a railway enthusiast (which he obviously was). I've now found the video on YouTube, where he calls himself M-Train. So if you like watching level crossings operating, he has more like this ...
https://youtu.be/7sCDrGmJ5Yw

He said the emergency number goes to the relevant signaller, and they get a lot of non-emergency stuff: complaints and insults mainly. I'm surprised there isn't an operator to screen calls in this sort of urban area.

We both thought one of the zigzags (the far one in the video) was rather low - perhaps to improve the sighting for drivers? Well, a driver's eye view doesn't support that, what it really shows is how dense the thicket of signs and posts is there.

The main factor is, I'm sure, that there are three main ways of applying these markings (that I've seen used here - and many more I've not). Paint is obviously likely to wear off, and most notably so on plastic surfaces like the level crossing boards (have you tried painting drainpipes?).

Then there's the gloop - officially it's a thermoplastic resin - which forms a thick solid layer. This will eventually break up like the road itself, but does seem more durable.  I see cold gloop is now available, and lasts even better.

When the Wokingham crossing and junction were rearranged in 2015, some of the white lines at the junction were applied as sticky shapes. The process involved preheating the road with as gas torch, then rolling them down. It did not work, and they got lifted up, and stuck down on other markings - which looked really bad, and pretty confusing.