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Old November 20th, 2015, 01:11 PM   #1021
telemaxx
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I am sure you have to switch off certain safety systems when flying certain maneuvers.

What I wanted to make clear was that the high speed rail system in Spain in that curve was not safe, whereas in France the high speed rail system is safe because they have continuous safety systems.

I think that the Spanish railways were wrong when they left the risk to brake in time in that curve to the conductor alone with no additional safety systems. This is for two reasons. First, commercial rides occur on a regular and frequent basis. Risk is probability (of failure) times consequence. Probability of failure increases if a lot of trains pass this curve. The conductor is alone, so the whole responsibility is on one person, who maybe is already at the end of his shift. Second, the consequences are also a lot higher with many more passengers on board.

A test run is something different. It is an event with a lot of preparation. Only experienced conductors are chosen. Three people are present in the driver's cab. And I think (but I am not sure about this) that people in the cars also have some measurement devices that tell them where they are, what the vibrations are etc. So that the safety system of the line was switched off does not necessarily mean that they had no GPS or other measurement device whatsoever. The question is rather why nobody noticed anything. Was there anything wrong with the devices? Were they just distracted because they had 7 people in the driver's cab? We don't know yet, so for me it is too soon to say that further technical safety measures should be implemented for test rides. Especially as long as the risk of a human factor isn't reduced by not allowing non-expert people in the driver's cab etc.
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Old November 20th, 2015, 03:49 PM   #1022
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Originally Posted by telemaxx View Post
A test run is something different. It is an event with a lot of preparation. Only experienced conductors are chosen. Three people are present in the driver's cab.
I am afraid, 'test run mode' does not equal more professionalism.
See the infamous Lathen train collision for example.

Also, since you brought up airplanes, 'three experienced pilots' did not mean anything, when the perfectly functional Air France Flight 447 crashed into the ocean in one of the worst display of piloting in the history of flight.
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Old November 20th, 2015, 07:32 PM   #1023
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Originally Posted by telemaxx View Post
What I wanted to make clear was that the high speed rail system in Spain in that curve was not safe, whereas in France the high speed rail system is safe because they have continuous safety systems.
Stop this shit. The curve in Santiago belongs to the conventional line. As any conventional line in Spain the signalling system is based on ASFA and the speed control is exported to the driver. I may agree that ASFA system is not the latests trend in signalling and that it lacks serveral features, but if one can not rely on the driver then we should forbid all trams, all buses and other transport mean where the driver, pilot, or whorever human being plays a role.

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Originally Posted by telemaxx View Post
I think that the Spanish railways were wrong when they left the risk to brake in time in that curve to the conductor alone with no additional safety systems. This is for two reasons. First, commercial rides occur on a regular and frequent basis. Risk is probability (of failure) times consequence. Probability of failure increases if a lot of trains pass this curve. The conductor is alone, so the whole responsibility is on one person, who maybe is already at the end of his shift. Second, the consequences are also a lot higher with many more passengers on board.
As said before, let us close all tram lines worlwide, many commuter and regional lines, VFR flights, buses and the like.

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A test run is something different. It is an event with a lot of preparation. Only experienced conductors are chosen.
Rubbish! Are you suggesting that the commercial drivers are not experienced?
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Old November 20th, 2015, 08:54 PM   #1024
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Originally Posted by telemaxx View Post
I am sure you have to switch off certain safety systems when flying certain maneuvers.

What I wanted to make clear was that the high speed rail system in Spain in that curve was not safe, whereas in France the high speed rail system is safe because they have continuous safety systems.

I think that the Spanish railways were wrong when they left the risk to brake in time in that curve to the conductor alone with no additional safety systems. This is for two reasons. First, commercial rides occur on a regular and frequent basis. Risk is probability (of failure) times consequence. Probability of failure increases if a lot of trains pass this curve. The conductor is alone, so the whole responsibility is on one person, who maybe is already at the end of his shift. Second, the consequences are also a lot higher with many more passengers on board.

A test run is something different. It is an event with a lot of preparation. Only experienced conductors are chosen. Three people are present in the driver's cab. And I think (but I am not sure about this) that people in the cars also have some measurement devices that tell them where they are, what the vibrations are etc. So that the safety system of the line was switched off does not necessarily mean that they had no GPS or other measurement device whatsoever. The question is rather why nobody noticed anything. Was there anything wrong with the devices? Were they just distracted because they had 7 people in the driver's cab? We don't know yet, so for me it is too soon to say that further technical safety measures should be implemented for test rides. Especially as long as the risk of a human factor isn't reduced by not allowing non-expert people in the driver's cab etc.
I still think it's silly that nowadays a high-speed test is run with fail-safe safety systems disabled. Can they not be easily adjusted for 10% overspeed? This accident was an example of "don't need to do that, just disable it, was fine so far".

They overshot breaking point for 1 km going at 330 km/h. That's 11 seconds! Human error was a mattter of when, not if.
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Old November 20th, 2015, 10:22 PM   #1025
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This. It doesn't make sense to turn off the safety system even if they plan to run at 110% of commercial operation speed. All they have to do is reprogram the safety system so the threshold is 10% more. The safety system is still in place to prevent the train from going into that curve at more than 176km/h. All those are done by software so it should have minimum cost and time penalty.

Also is it true that the curve isn't covered by ETCS? Unless there is some sort of technical reason behind it, this seems to me like a lapse in safety procedures and possibly safety culture within SNCF.
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Old November 20th, 2015, 11:48 PM   #1026
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Also is it true that the curve isn't covered by ETCS? Unless there is some sort of technical reason behind it, this seems to me like a lapse in safety procedures and possibly safety culture within SNCF.
Where have you read that? I doubt that SNCF is as dumb as Renfe.
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Old November 21st, 2015, 12:25 AM   #1027
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Originally Posted by k6uelind View Post
Whether the safety system was absent or just disabled or whether it was a test run or a commercial service does not change much in terms of the responsibility of the operator to preserve human life. They knew the risks but they thought it was acceptable. Maybe it was a right decision to not mitigate the risks. I believe it was a wrong decision.

I test industrial hardware and software systems for a living. Ensuring safety during testing is my top priority. I am sure this is a lesson SNCF will learn from. I am sad they did not learn from the mistakes of others.
I totally agree with you that serious mistakes were made in the test procedures. I don't know how difficult or easy it is to reprogram a 10% overspeed into the safety systems. Even if it couldn't have been done or it would've been too difficult, they should've, let's say, set the braking point in the test several kilometres early or indeed set up a more rudimentary warning system. The biggest problem on this line was the rapid decrease in speed from 300+ km/h to much less than 200 km/h.

My main point was that testing, especially if it includes doing something the system (railway, aircraft etc.) is not meant to do in normal operation includes a much higer risk than regular service. For example, speed tests on trains are often performed on railway sections that wouldn't allow such speeds in normal operation. Even the Estonian FLIRT trains were tested at around 175 km/h while the signalling only allows for 120 km/h. In Poland the Pendolino ED250 reached 293 km/h during tests, way above the allowed speed for trains in normal operation. You can be well assured that the regular safety systems don't work in such circumstances.
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Old November 21st, 2015, 12:35 AM   #1028
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I see a lot of people saying "Couldn't they have just reprogrammed the safety system?", but I don't think anyone has looked at the technical implications that such a change entails.

In the TVM-430 system, adding an additional speed step is not easy at all. Under ETCS it is supposedly easier to adjust the maximum permissible speed, but I am not aware if the ETCS system on the LGV Est Phase 2 has been commissioned yet and if the test train has received the correct encryption keys required for communication with the control system.

For now, let's focus on the TVM-430 system which is in use on nearly all high speed lines in France. Apart from France, TVM-430 is also used in the Channel Tunnel and on High Speed 1 in the UK. The TVM-300 system was developed in the 1970's, the succeeding TVM-430 system was developed in the 1980's. At that time, technology was not as far advanced as it is today and thus, the designers had to make some compromises.

The TVM system works by encoding signals onto the tracks, which are then picked up by receivers on board the trains. These signals work on various frequencies and can transfer a lot of relevant information, but the precise detail is limited. As a consequence, the TVM system is not capable of telling the train "the maximum allowed speed on this section of track is 230 km/h".

Instead, the trackside equipment transmits to the train some identifying information about the kind of infrastructure the train is running on (the "network code") and it transmits a "speed code". The equipment onboard the train translates the combination of the network code and speed code into the maximum allowed speed at that time.

The "speed code" depends on the amount of unoccupied blocks in front of the train: the more blocks are free, the higher the allowed speed will be. However, not all infrastructure has the same maximum allowed speeds and this is where the network code comes into play: in the Channel Tunnel it will allow 160 km/h, on LGV Est it will allow 320, on the Belgian LGV 1 it will allow 300 km/h, and so on.

So, in order to have trains travelling at 360 km/h to be protected by TVM-430, the trackside equipment will have to be modified. A new network code will have to be introduced which is then emitted along with the rest of the speed information. But apart from that, the software in the train has to be updated as well. The new network code will have to be interpreted and used to calculate new accurate braking curves.

This is a lot fo software development work for a situation which will not occur in real life scenarios, as the commercial speed for trains is limited to 320 km/h - a speed which is already supported by TVM-430.
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Old November 21st, 2015, 12:46 AM   #1029
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I already said additional safety measures can be implemented! A simple smartphone alarm going off because of a GPS geofence would have saved the lives of 11 people! There are numerous other ways.
GPS equipment is used extensively during test runs, for this very reason. However, SNCF stated that too many people were in the cab, that the atmosphere was noisy and that the driver's view was partially blocked.

It's entirely possible that the driver missed the GPS alarm because of this, and only noticed that he had gone too far when spotting a "PK" sign (point kilomètre, positioning marker board).

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So, are you basically saying "It was a test run. The people on the train knew this and signed a paper. They died, but this can happen during testing. Case closed."?
It's their choice to participate in these tests. They are well aware that risks are involved and that the chance exists that they may get hurt - that's why they're trying things.

Those friends and family members should not have been on board, and their presence should be scrutinized. I'm speculating here, but if the driver's nephew or son was in the cab I am pretty sure that he wanted to show off a bit. "Look Gérard, this is the speedometer - as you see we're going 275 km/h now. And this is the phone that I use to contact the signaller with."

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I am confident that no safety systems are turned off while testing commercial airplanes. I would be surprised if I was wrong. Also, you do not want to compare two train accidents but you do compare testing an airplane to testing a train service? The training and discipline of commercial airplane pilots is from an entirely different class. And yet half of the airplane accidents are caused by human error.
When a new airplane is built and the prototype is being tested, this happens with flight safety systems disabled. The aim of the tests is to stress the plane to its limits, something which would be made impossible by these very safety systems.
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Old November 21st, 2015, 01:21 AM   #1030
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GPS and or an odometer are pretty trivial solutions for a temporary substitute for a full train control system especially on a single new section.
It is really not that hard to let the train count the distance it traveled by itself and then brake automatically.
Like other have said already, 'testing mode' should not free you from your responsibility to provide passive safety.
'They signed a statement, they knew the risk', is not an acceptable excuse from a big railway organisation like SNCF.
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Old November 21st, 2015, 01:39 AM   #1031
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And how do you guarantee that such a GPS-based system always works as it should and intervenes at the right location? How do you prevent test drivers from relying too much on such a system?

As much as I agree with you that SNCF has a responsibility to provide safety, it is a test run after all and the test crew knows they are taking risks. It's up to the driver(s) in the cab to take appropriate measures to mitigate these risks during test runs.

Based on the publicly available information, not only were there way too much people in the cab (seven people, while two or three were expected), the driver also let it happen that part of his sight was blocked, the noisy atmosphere only distracting him further. I'm quite confident the driver as well as the backup drivers let themselves get distracted by the other people in the cab, causing them to miss critical position indicators.
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Old November 21st, 2015, 02:09 AM   #1032
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GPS doesn't work in long tunnels to begin with...
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Old November 21st, 2015, 11:23 AM   #1033
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So, in order to have trains travelling at 360 km/h to be protected by TVM-430, the trackside equipment will have to be modified. A new network code will have to be introduced which is then emitted along with the rest of the speed information. But apart from that, the software in the train has to be updated as well. The new network code will have to be interpreted and used to calculate new accurate braking curves.

This is a lot fo software development work for a situation which will not occur in real life scenarios, as the commercial speed for trains is limited to 320 km/h - a speed which is already supported by TVM-430.

Could the software on the train be adjusted to interpret beacons with 10% overspeed allowed? Fore example, if beacon sets 160 km/h limit, train software calculates breaking curves for 176 km/h? It's much easier to modify software on a single test train. And for 200 or so test runs (more test runs, bigger risk of human error), I think it's not that much trouble.
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Old November 22nd, 2015, 06:12 AM   #1034
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Originally Posted by k6uelind View Post
  • High speed railway section that suddenly terminates with a sharp curve
  • No safety system
  • Operator knows safety system not operational and decides that the risk of driver not being able to brake correctly is acceptable
  • Driver is not able to brake correctly, train derails at high speed and people die
The "high speed railway section that suddenly terminates with a sharp curve" is of no problem if you have the speed control systems working, and operators not being distracted... in fact, he must be aware of that fact and STARTING TO BRAKE before the point needed.
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Old November 22nd, 2015, 06:14 AM   #1035
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I am afraid, 'test run mode' does not equal more professionalism.
See the infamous Lathen train collision for example.
Oh, the Titanic of the maglev that "will never crash", and because of that the "tin" was not designed to passenger survival... it was the end of the Transrapid. At present the only test track is the very expensive white elephant at Shanghai.
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Old November 22nd, 2015, 09:52 AM   #1036
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Oh, the Titanic of the maglev that "will never crash", and because of that the "tin" was not designed to passenger survival... it was the end of the Transrapid. At present the only test track is the very expensive white elephant at Shanghai.
Most all HSR are made for collision avoidance not collision survival. The only one I know that is built for collision survival is the Acela which is built like a tank. Although I doubt people will survive when it hits a curve at 320Km and derails.
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Old November 22nd, 2015, 11:39 AM   #1037
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Stop this shit. The curve in Santiago belongs to the conventional line. As any conventional line in Spain the signalling system is based on ASFA and the speed control is exported to the driver. I may agree that ASFA system is not the latests trend in signalling and that it lacks serveral features, but if one can not rely on the driver then we should forbid all trams, all buses and other transport mean where the driver, pilot, or whorever human being plays a role.
Are you maybe able to see a difference between the end of high speed line with 300 km/h and a tram line which usually doesn't go much faster than 50 km/h. That corresponds to a braking distance of approx. 3400 m vs. 100 m.
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Old November 22nd, 2015, 12:33 PM   #1038
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Most all HSR are made for collision avoidance not collision survival. The only one I know that is built for collision survival is the Acela which is built like a tank. Although I doubt people will survive when it hits a curve at 320Km and derails.
The transrapid crashed at 162 km/h and ended with 23 deaths (most of them passengers...).
TGV derailed at 243 km/h, 11 deaths (and were not passengers).
And in other high speed derailments only light injuries.
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Old November 22nd, 2015, 12:40 PM   #1039
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Most all HSR are made for collision avoidance not collision survival. The only one I know that is built for collision survival is the Acela which is built like a tank. Although I doubt people will survive when it hits a curve at 320Km and derails.
About crumple zones:

http://www.railwaygazette.com/news/s...standards.html

https://books.google.com.uy/books?id...%20TGV&f=false

http://www.alstom.com/Global/Transpo...h%20AGV%20.pdf

From here: http://stp.diit.edu.ua/article/viewFile/20353/17961

"5. Crashworthiness Following recent trends in the auto industry, there is significant effort going into passive security of TGV train sets. Using new software for railroad crash simulation, called ’Pamcrash’, the TGV Duplex structure was optimized on a supercomputer. The trailers have extremely rigid bodies with deformable, energy absorbing crush zones at the ends. The coupling between the power cars and trailers has also been reviewed; it still uses screwlink couplers with buffers, but the buffers have structural fuses built in so that they fold away under crash loads. The car ends have been reviewed to prevent the power car from climbing onto the first trailer. For multiple unit operation, the Scharfenberg couplers in the noses of the train set have been designed to collapse under heavy loads, so that two power cars coupled nose to nose can make firm contact with each other to prevent telescoping. This is in addition to the energy absorbing ram shield already mounted in the nose of all TGV power cars to defend the cab cubicle."

About FRA standards:

http://www.ft.com/cms/s/0/a98e0b5c-d...#axzz3sDSFxqE6
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Old November 22nd, 2015, 03:44 PM   #1040
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SamuraiBlue is just a M**l** troll - appearing in threads on High Speed Rail whenever someone mentions the 'm-word' to defend that tech. It backfires as it is clear that the defence is coming from a place of near-total ignorance about HSR.
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