Talk:Lac-Mégantic rail disaster/Archive 2
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List of deceased
The names listed so far do not add up to the number 47 indicated in the article. When I went to the reference there are indeed 47 names listed but it shows only 40 confirmed dead and 7 deemed deceased by the coroner. I was going to add the missing names but I was wondering if we should list them like the coroner does with the presumed dead separate from the known deceased? Also I believe we should use the official coroner report for our WP:RS for confirmed deceased and presumed deceased rather than news reports. Thoughts?--Daffydavid (talk) 22:22, 6 July 2014 (UTC)
Final report
The TSB have released the final report into the accident. Mjroots (talk) 19:30, 20 August 2014 (UTC)
Brakes
I've not read all of the final report yet, but the TSB basically seems to be saying that a design fault in the brake system was the underlying cause of the accident. As I understand it, air pressure is needed to apply the brakes. This is the complete opposite of practice in the UK, where air pressure is required to release the brakes and maintain them in a released state. This was learnt in the mid-Nineteenth century with the invention of the vacuum brake. Early systems required a vacuum to be created to apply the brakes. It was quickly realised that there was a serious flaw in this system and the automatic vacuum brake came into use. Question is, can we say this in the article, or are we getting into the realms of WP:OR here. Mjroots (talk) 09:40, 21 August 2014 (UTC)
- I don't think that it was a design fault. The findings are in Section 3, and it appears that there were several failures in operating practice, such as insufficient hand brake application; inadequate brake tests; known faults with a locomotive's engine fault; insufficient training and risk assessment.
- Re the brakes. When I search (from the top) for "brake", the first hit is in section 1.1, which says "brought to a stop using the automatic brakes, ... The LE applied the independent brakes to the locomotive consist. He then began to apply the hand brakes on the locomotive consist and the buffer car (7 cars in total), and shut down the 4 trailing locomotives. Subsequently, the LE released the automatic brakes and conducted a hand brake effectiveness test without releasing the locomotive independent brakes". There are three separate braking systems mentioned here:
- the automatic brake - described in section 1.9.1 - an air brake where atmospheric pressure applies the brake and an increase in air pressure releases the brake
- the independent brake of the locomotive - described in sections 1.9.2 and 1.9.5 - an air brake where atmospheric pressure releases the brake and an increase in air pressure applies the brake
- hand brakes - section 1.10 - mechanical
- The operation of the independent brake - i.e. atmospheric pressure releases the brake - is not uncommon on British locomotives, which typically have separate brake controls (and thus separate brake systems) for loco and train. It is only the continuous brake (i.e. that for the train) that is required to be automatic under British law.
- Also of interest is Table 1 in Section 1.13.1 --Redrose64 (talk) 10:53, 21 August 2014 (UTC)
- @Redrose64: - yes, those are the direct causes, but my question was re the underlying cause. Mjroots (talk) 11:53, 22 August 2014 (UTC)
- @Mjroots: All automatic brakes - whether air or vacuum - will leak off if given sufficient time. This is because it is not possible to produce a perfect seal between the brake cylinder and the piston within it - air will slowly leak from one side to the other. --Redrose64 (talk) 12:49, 22 August 2014 (UTC)
- re Mjroots: Mentioning that the brake system was not by fail-safe is not OR. It is a prime design choice (and principle flaw). It may be illustrative & correct to describe something of the opposite (UK) system. -DePiep (talk) 09:36, 26 August 2014 (UTC)
- The report says (section 1.1): With no locomotive running, the air in the train’s brake system slowly began to be depleted, resulting in a reduction in the retarding force holding the train. That leaves no doubt about the design. -DePiep (talk) 09:44, 26 August 2014 (UTC)
- Thank you, DePiep. That was my point. If the system is that air pressure has to be created to release the brakes, then any lack/depletion of air pressure is going to have no effect, and all five locomotives would have remained fully braked. Apply the system to the whole train, and there's no way that the accident would have happened. Mjroots (talk) 10:33, 26 August 2014 (UTC)
- Yes. btw, I understand this was not a single point of failure (because, had other brake system(s) functioned OK, it would/could have been safe). But it is a system internal liability. This vacuum system in itself is too dependent. -DePiep (talk) 11:11, 26 August 2014 (UTC)
- @DePiep and Mjroots: You both seem to be missing key points. The first mention of brakes is indeed in Section 1.1, in the paragraph beginning "At around 2250, the train arrived at Nantes". In the first three sentences, three types of brake are mentioned: the automatic brakes, the independent brakes, and the hand brakes. These three different types of brake are described in greater detail in Sections 1.9 and 1.10; please read the whole of section 1.9. The UK system is not "opposite": it works on the same principle as the automatic brake described in section 1.9.1 and is also prone to the other problems, including those in section 1.9.5 (Leakage). There are two brake pipes: the brake pipe proper (which is painted red in the UK), where low pressures apply the brake and high pressures release it; and the reservoir pipe (yellow in the UK) which is normally kept at high pressure by the compressor on the loco. The reservoir pipe is used to feed the air reservoirs mounted on each vehicle, and these are connected to one side of the brake cylinder. The other side of the brake cylinder is connected to the brake pipe. --Redrose64 (talk) 20:51, 26 August 2014 (UTC)
- Tell us: which of the brake systems failed? -DePiep (talk) 21:10, 26 August 2014 (UTC)
- report section 1.1: "the LE released the automatic air brakes, but the independent brakes were left applied." (to test handbrakes, which so were applied by then). Nowhere do I read the automated brakes were re-applied. In time (hours), the locomotives independent brakes, that rely on active pressure, were released by leakage. Then it appeared that hte handbrakes alone did not hold the train on a slope.
- So, if I am correct it was the LE that did not re-apply the automated brakes (
release pressure) to blame? - Must say, the report is hard to read for a technical mind like me. All facts are verbose, not a table or timeline or overview in sight. Then this confusing description of the brake systems & brake processes. (this x-clarity could be helpful for some parties involved though). -DePiep (talk) 21:23, 26 August 2014 (UTC)
- @DePiep and Mjroots: You both seem to be missing key points. The first mention of brakes is indeed in Section 1.1, in the paragraph beginning "At around 2250, the train arrived at Nantes". In the first three sentences, three types of brake are mentioned: the automatic brakes, the independent brakes, and the hand brakes. These three different types of brake are described in greater detail in Sections 1.9 and 1.10; please read the whole of section 1.9. The UK system is not "opposite": it works on the same principle as the automatic brake described in section 1.9.1 and is also prone to the other problems, including those in section 1.9.5 (Leakage). There are two brake pipes: the brake pipe proper (which is painted red in the UK), where low pressures apply the brake and high pressures release it; and the reservoir pipe (yellow in the UK) which is normally kept at high pressure by the compressor on the loco. The reservoir pipe is used to feed the air reservoirs mounted on each vehicle, and these are connected to one side of the brake cylinder. The other side of the brake cylinder is connected to the brake pipe. --Redrose64 (talk) 20:51, 26 August 2014 (UTC)
- Yes. btw, I understand this was not a single point of failure (because, had other brake system(s) functioned OK, it would/could have been safe). But it is a system internal liability. This vacuum system in itself is too dependent. -DePiep (talk) 11:11, 26 August 2014 (UTC)
- Thank you, DePiep. That was my point. If the system is that air pressure has to be created to release the brakes, then any lack/depletion of air pressure is going to have no effect, and all five locomotives would have remained fully braked. Apply the system to the whole train, and there's no way that the accident would have happened. Mjroots (talk) 10:33, 26 August 2014 (UTC)
- @Mjroots: All automatic brakes - whether air or vacuum - will leak off if given sufficient time. This is because it is not possible to produce a perfect seal between the brake cylinder and the piston within it - air will slowly leak from one side to the other. --Redrose64 (talk) 12:49, 22 August 2014 (UTC)
- @Redrose64: - yes, those are the direct causes, but my question was re the underlying cause. Mjroots (talk) 11:53, 22 August 2014 (UTC)
- British railways do not use vacuum brakes anymore. See Vacuum brake. Vacuum brakes operate with relatively small pressure differences, which makes them unsuitable for long trains (pressure propagation takes too long, leaking is a big issue, needs large brake cylinders). Most railways - including US railways - use compressed air for braking. Those brakes are similar around the world, but may differ in many details.
- Freight trains have a single brake line, which both fills the reservoirs of the cars and controls the brake valves. Above a certain pressure the brakes get released, lowering the pressure more or less quickly applies the brakes (using air from each car's reservoir). Thus they *are* fail-safe in the short term, e.g. if a train gets split into two sections and the brake line ruptures. But because they rely on air pressure in the brake cylinders to work, they are not fail-safe in the long term due to leakage.
- However, in this case the engineer apparently only applied the independent brake of the locomotives, which feeds air directly into the brake cylinders of the locomotives and thus is not fail safe in any way.
- In theory, the brakes on the cars should have been applied by the sinking air presure in the brake line, but this didn't happen (presumably because all the leakage combined with a slowly sinking pressue prevented a large enough pressure difference to build up in the brake valves). But even if that had happened, the leakage would have made sure that the brakes got released again after some time, so it probably would not have changed the outcome.
- The underlying issue? You can't reliably secure a train using air brakes. Now point your finger at the brake system, at the engineer or at the company defining operating procedures, whichever way you like... --Kabelleger (talk) 20:16, 26 August 2014 (UTC)
- @Kabelleger: - agree that the automatic vacuum brake is not in common use now, although it is found on some heritage railways. However, the principle remains the same. If the system is that pressure has to be created to release the brakes, then it won't matter a jot if pressure leaks off. Mjroots (talk) 20:56, 26 August 2014 (UTC)
- Sure, you're probably right in thinking that it would be possible to construct a brake system that works this way (although such a system *might* have other, serious disadvantages). And sure, you can call it the underlying cause. But in itself the current braking system is not a big problem; it only turns into a problem if its behaviour is not accounted for due to bad procedures or human error. --Kabelleger (talk) 21:28, 26 August 2014 (UTC)
- You can't reliably secure a train using air brakes. - unproven. Here, the indep brakes works on the locs only, and require active pressure to make them brake. (then: leaks → no brakes → downslope). The "automated" unbrake by pressure system, here present, did not work because it was not applied (after the handbrake-test). -DePiep (talk) 21:44, 26 August 2014 (UTC)
- The automatic brake leaks off. Short term, it will stop the train and hold it for a reasonable period. It won't hold it in one place overnight. --Redrose64 (talk) 21:48, 26 August 2014 (UTC)
- When autobrake is activated, the auto brake's leak does not matter: underpressure=break.
End of story. - Point 1: when the autobrake pipes leaks, breaking will follow. That will be a problem while driving the train. Where the leaks in the autobrake sytem big enough, it would have gone into working that night. (Remember, the train was parked with autobrakes pressured=no-breaking).
- Point 2: It was the indep brakes in the loco set that a. requires pressure to brake and b. lost pressure (with no resupplement) so they released.
- Point 3: If I am right, I must admit to R64 that the fail-safe brake design principle is not involved. -DePiep (talk) 22:01, 26 August 2014 (UTC)
- The automatic brake only works as long as there is air pressure in the reservoirs of the cars, because that's the air used to drive the brake cylinders. With leaky brake valves and brake cylinders, and no way to fill the reservoirs (because that would need an additional air supply line and a working locomotive), air pressure (and thus braking force) can only go one way over time: Down. You can *hope* that this process will be slower than with the independent brake, but that's hard to quantify. --Kabelleger (talk) 06:50, 27 August 2014 (UTC)
- Agree Kabelleger, the autobrake system requires pressure too: in the car-mounted cylinders. (That would support the design flaw statement made by Mjroots here; is this the same in UK btw?). Then, in this case, two questions: 1. was autobrake applied? (No, as I read it).
2. If applied, could leaks make it fail as R64 says (of theoretical interest only)? ' It won't hold it in one place overnight R64 says: is that correct, for say over 12 hrs?-DePiep (talk) 07:31, 27 August 2014 (UTC)
- Agree Kabelleger, the autobrake system requires pressure too: in the car-mounted cylinders. (That would support the design flaw statement made by Mjroots here; is this the same in UK btw?). Then, in this case, two questions: 1. was autobrake applied? (No, as I read it).
- The automatic brake only works as long as there is air pressure in the reservoirs of the cars, because that's the air used to drive the brake cylinders. With leaky brake valves and brake cylinders, and no way to fill the reservoirs (because that would need an additional air supply line and a working locomotive), air pressure (and thus braking force) can only go one way over time: Down. You can *hope* that this process will be slower than with the independent brake, but that's hard to quantify. --Kabelleger (talk) 06:50, 27 August 2014 (UTC)
- When autobrake is activated, the auto brake's leak does not matter: underpressure=break.
- The automatic brake leaks off. Short term, it will stop the train and hold it for a reasonable period. It won't hold it in one place overnight. --Redrose64 (talk) 21:48, 26 August 2014 (UTC)
- @Kabelleger: - agree that the automatic vacuum brake is not in common use now, although it is found on some heritage railways. However, the principle remains the same. If the system is that pressure has to be created to release the brakes, then it won't matter a jot if pressure leaks off. Mjroots (talk) 20:56, 26 August 2014 (UTC)
Everyone who understands how train brakes work, please hold your hand up! The truth is that the train brakes will always release because they always leak. They cannot be trusted for a long period of time. Wheel chalks and hand brakes are the only good way to secure a train for long periods of time. Relying on running engines and the engine brakes to secure the train while unmanned is not a good practice, as proved in this case. The brake system did what it should have been expected it would. It would have not caused a problem if the engines had not been shut down, which demonstrates why relying on an engine running on an unmanned train is not a good practice. More hand brakes should have been set. Chalks should have been used. I'm a brakeman, on a railroad and I only got involved in this because the text in the article is both confused and inaccurate. Corumplex (talk) 16:51, 14 September 2018 (UTC)
Notes
A reading note. About the photo 19 car numbering in the report. It shows damage to the tank cars by coloring individual cars in a picture of the site. The picture is an aerial overview, like photo 1 to compare. I think the numbering in this is not the numbering of cars #1 to #63, as might be expected.
A. There were 72 tank cars in the train. The last nine did not derail, and are not in the picture. Probably they were towed away during the fire. That leaves 63 tank cars on the derailment site. #63 is the one standing seemingly OK right on the public road crossing.
B. But the numbering in photo 19 has a shifted counting. Extending the last one marked "62", there would follow 63, 64, 65. However, 64 and 65 are not in the picture (64–72 being towed away). Also, the first numbered "12" more reasonably seems to be #10, when counting the scattered tank cars #1–#8 in the overview photo 1. (and #9 standing undamaged a bit away from the huge car stack). So car numbers in photo 19 should red #"number minus two". -DePiep (talk) 10:57, 27 August 2014 (UTC)
Emergency Response taking a long break?
The report states this:
- 1.21 Emergency response For several hours [during the aftermath], all work at the site stopped due to concerns about the ability of the railway to cover all emergency response costs. The stoppage affected the progress of the emergency response and environmental remediation, resulting in oil migrating back to zones that had earlier been declared safe.
and
- 3. Findings, 3.3 Other findings #5: the emergency response was conducted in a well-coordinated and effective manner.
To me this is a contradiction. And it is strange that the TSB did not work on this. After all, they do recommend improvements to tank cars to reduce post-accident damage, so this could very well be in their field too. -DePiep (talk) 14:10, 27 August 2014 (UTC)
Units imperial or metric
Shall we change units to be all in Imperial (mi, ft) instead of metric? The TSB report only uses imperial, and does not convert to metric. That way, we can use the exact figures mentioned. -DePiep (talk) 12:38, 27 August 2014 (UTC)
- Both units should be displayed (using {{convert}} with the article consistently displaying either metric or imperial first (presently about 2/3rds show metric first, 1/3rd imperial first) per MOS:UNITS. There is no guidance on that page about which set of units are conventionally used in Canada, is there guidance elsewhere? Thryduulf (talk) 00:42, 21 October 2014 (UTC)
- Is what I meant to say: all in one unit, then the other one by conversion & {convert}. IIRC the TSB report had one consistently, but it did not match with the other sources in the page. No time to research this. -DePiep (talk) 00:51, 21 October 2014 (UTC)
- All railroads in North America use imperial units as do all the regulatory agencies governing them. The metric units in the article are primarily because Canadian newspapers have converted the figures for their articles. This introduces the possibility of conversion errors and I would suggest we use imperial as the default and have it converted to metric using the template.--Daffydavid (talk) 03:06, 21 October 2014 (UTC)
- Is what I meant to say: all in one unit, then the other one by conversion & {convert}. IIRC the TSB report had one consistently, but it did not match with the other sources in the page. No time to research this. -DePiep (talk) 00:51, 21 October 2014 (UTC)
New criminal charges laid
New charges have been filed by Transport Canada. Mjroots (talk) 06:54, 24 June 2015 (UTC)
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Update needed re: resumption of oil shipments
We have a statement that resumption of oil shipments by rail through the town was expected to begin in 2016. That was 3 years ago; what's the current status? Did this happen or have resident concerns been addressed? 136.159.160.5 (talk) 19:36, 13 May 2019 (UTC)
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