Explosion in Quebec, near Maine

Hytec Jul 6, 2013

  1. Seanem44

    Seanem44 TrainBoard Member

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    I just read the same. The firefighters did do their job, and sadly this will probably effect the ones who were their mentally, knowing what happened. However, it is the MM&A's fault in my opinion. After the fire, the train should have been deadlined and there should have been an employee there 24/7 until they moved the thing, just in the chance of a flare up. This was mishandled by the MM&A. It is so sad. Most of those people probably had no clue what hit them.

    http://www.cnn.com/2013/07/09/world/americas/canada-runaway-train/index.html?hpt=hp_t2
     
  2. SteamDonkey74

    SteamDonkey74 TrainBoard Supporter

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    I thought the failure mode on air brakes was that they applied, stopping the individual cars.
     
  3. randgust

    randgust TrainBoard Member

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    Brakeline pressure feeds into the air reservoirs, charging them and 'pumping up' the train brakes to release. Releasing air in the trainline triggers the triple valve to release the stored air in the car air reservoirs to apply the brakes. Resuming pressure in the trainline recharges the reservoirs, does not hold the brakes on, but can pressure-maintain the system. If air is shut off/uncoupled/released, the brakes do immediately apply, but sooner or later the reservoirs leak off and brakes slowly release off again, depending on how leaky the entire system is. Then, all you have holding a car/train is the handbrakes, and/or the independent brake on the locomotive - a totally separate system. Because of this, all railroads have procedures on setting handbrakes on equipment when parked, and testing the handbrakes to make sure the train is actually holding. You can depend on air to fire the brakes on the train itself, but you can't depend on air to hold them. If you exhaust all the pressure differential between the reservoirs and the trainline by repeated brake applications without recharging the reservoirs, you've 'run out of air' and until the system is recharged, brakes can't re-apply. That's the classic train runaway under movement headed downgrade.

    Running away in this situation is more complex, but if the train was being held in place with minimal handbrakes and just the locomotive(s) independent brake holding the consist it appears possible that shutting down the only running unit would kill the independent (straight air holding locomotive brakes on), and insufficient handbrakes could let it roll... but we really don't know that yet.


    See: http://www.sdrm.org/faqs/brakes.html
    also: http://railtown.team.parks.ca.gov/volunteers/Document Library20/1/ABTH Manual Railtown.pdf

    Not enough information yet to know what the situation was. The quality of the reporting has certainly been suspect and most have no idea how anything actually works. It gets really tangled in translation. Our NTSB just takes forever to properly investigate an accident and by then most people have forgotten about it anyway. I suspect that Canada will expedite this as rapidly as the wreckage cools.
     
  4. BOK

    BOK TrainBoard Member

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    Randy, that's a great description of how the automatic air brake system operates. Do you mind if I include your comments in my training notes for teaching new hire conductors and engineers?

    Thanks,

    Barry
     
  5. HemiAdda2d

    HemiAdda2d Staff Member

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    What are the rules for applying handbrakes to parked trains? From old ETTs I have read, the rules are different based on tonnage, grade and other factors, changing the minimum amount of applied handbrakes.
     
  6. Mike VE2TRV

    Mike VE2TRV TrainBoard Member

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    It's always hard to keep track of all the stories coming out. Depending on who you listen to, the locomotives may or may not have been at the head of the train. One witness to the disaster said he saw the locomotive with no lights on. Some news outlets are reporting that the cars ran away without the locomotives, which implies that the locomotives were at the rear of the train at the time and the tankers somehow came uncoupled...

    ???

    I sure hope the TSB people will get this sorted out. All that hearsay and he-said-she-said is irritating.

    And on the subject of irritation, the head of MM&A will be visiting Lac Megantic today... If his trains are a fire hazard, wait until he sees the torch-bearing mob...
     
  7. Hytec

    Hytec TrainBoard Member

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    He also may be offered personal transportation out of town that includes tar, feathers, and a rail....ya think?
     
  8. Seanem44

    Seanem44 TrainBoard Member

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    Especially after laying blame and directly pointing fingers at the Fire Department in an effort to save some sort of face.
     
  9. BoxcabE50

    BoxcabE50 Staff Member TrainBoard Supporter

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    We still do not know who is at fault, regardless of the possible lynch mobbing of anyone actually innocent.
     
  10. HemiAdda2d

    HemiAdda2d Staff Member

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    All this media postulation of what happened needs to stop.
    http://edition.cnn.com/2013/07/09/world/americas/canada-runaway-train/

    The NTSB or whoever in Canada does wreck investigations needs to finalize its report before anyone needs to go around pointing fingers.

    IF the loco caught fire and a separate one was not immediately put in operation to maintain brake pipe pressure, the plausible explanation is that the air leaked off gradually releasing the brakes.

    I have an older copy of CP Rail's General Operating Instructions. Section 14, para 3 specifically calls out "locomotives attached" and "with engines running" in its Hand Brakes rules. I cannot imagine any other North American railroad's rules being drastically different in this regard.
     
  11. Mike VE2TRV

    Mike VE2TRV TrainBoard Member

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    By coincidence, MM&A runs along former CPR trackage that they sold off...

    The media are acting rashly throughout this affair. They report every rumor, theory, opinion and other putrid garbage that every Monday morning quarterback without a trace of knowledge about train operations happens to spill out. That is contrary to Journalism 101, first year course: if one doesn't have two independent sources for a story, don't publish it! Unfortunately, they all are looking for the sound bite, the juicy detail, the emotional story that will raise ratings, readership, and of course, revenue.

    Then the public, with the same lack of knowledge as the aforementioned quarterbacks, will paint all railroads with the same contaminated brush.
     
  12. BoxcabE50

    BoxcabE50 Staff Member TrainBoard Supporter

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    It's ALL about money. Selling ads or commercials is big dollar stuff. Keeping eyes and ears glued to your outlet is ALL that matters, never minding any damage left in their wakes. And this comes from a group we hear all too often espousing the evils of businesses making any profits. There's nothing like a bunch of greedy hypocrites...

    Those who are going to write about a topic should have some minimal knowledge of it, before they get started. This is far too often not the reality.
     
  13. Mike VE2TRV

    Mike VE2TRV TrainBoard Member

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    The MM&A chief visited Lac Megantic yesterday, and got a pretty frosty reception. While talking to reporters, he was heckled and insulted by some of the locals.

    And he changed his story about the wreck... for the fourth time. Any detective knows when someone changes their story, it's a big clue that there's a skeleton hidden in a closet somewhere.

    There may also be some issue with federal regulations on how many hand brakes should be applied for a parked train. A couple of years back, a train ran away in much the same manner, after the engineer applied nearly forty hand brakes - more than triple what the rules call for. A serious review needs to be made on this issue. I hope that the TSB makes that recommendation.
     
  14. HemiAdda2d

    HemiAdda2d Staff Member

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    As Randy suggested earlier, flat-spotted wheels will be the telltale of how many handbrakes were actually tied down. The TSB will certainly evaluate that in its report.

    Mike, can you give me a link to the opther derailment/runaway you mentioned? I'm curious what the reports say about it. ~40 handbrakes? wow!
     
  15. Mike VE2TRV

    Mike VE2TRV TrainBoard Member

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    I don't know the details about the other runaway, I just heard it on the radio on my way in to work this morning.

    As for the number of handbrakes applied by the MM&A engineer, he said it was twelve - the minimum recommended by regulations. Oh, the grade downhill from Nantes to Lac Megantic is 1.2%. The train was going 63 MPH when it derailed. Yikes.
     
  16. Mike VE2TRV

    Mike VE2TRV TrainBoard Member

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    I made a quick search and found it:

    http://naskapinews.com/2013/01/23/t...d-releases-full-report-on-qnsl-runaway-train/

    In short, the engineer had to stop the train with the emergency brakes, then applied 35 hand brakes. An hour later, the train ran away, but stopped without derailing 15 miles down the track.

    Ooooookayyyy....
     
  17. HemiAdda2d

    HemiAdda2d Staff Member

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    Is the grade in Nantes 1.2% as well?
     
  18. Hytec

    Hytec TrainBoard Member

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    I'm assuming the track speed through Lac Megantic is far less than 63, regardless of any restriction the town may have imposed slower than the physical requirement. I have no idea the car count or weight of the train, but hand brakes of only 12 cars, 96 wheels, would hardly make any difference on a 1.2% grade.

    Sad to speculate that as few as a dozen chocks would have prevented this. As a side-bar, the Saturn V Apollo launch vehicle, generating 38,000,000 Horsepower at full thrust prior to release at the launch pad, was secured by four (4) 2" diameter steel rods. The important physical phenomenon is that there is no measurable force when all motion is prevented. That is to say Force = Mass * Velocity (squared). When Velocity = Zero, there is No Force. So, I'd recommend chocks over hand brakes any time.
     
  19. Mike VE2TRV

    Mike VE2TRV TrainBoard Member

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    I don't know exactly what the grade is in Nantes, but it's obviously not zero. The 1.2% figure is the average grade down to Lac Megantic.

    Through town, over the level crossing and nearby turnouts, it's restricted to 10 MPH.
     
  20. Mike VE2TRV

    Mike VE2TRV TrainBoard Member

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    That QNS&L accident report is an interesting read. The ore gondolas - which belonged to the mining company and not to QNS&L, nearly all had some kind of faulty braking components, including improperly adjusted or unlubricated hand brakes. That means that the person setting the hand brake might put the usual amount of force on the brake wheel, but that doesn't mean that there is enough force pushing the brake shoes against the wheels. A visual inspection doesn't reveal that - only that the brake shoe is in contact with the wheel.

    If the MM&A engineer set the 12 hand brakes (or even more, had he done so), and most of them were faulty to begin with, there was no way that the train could have stayed put overnight if the sole engine maintaining brake air pressure was shut down by the fire dept. I think that the TSB, from experience with the QNS&L incident, will make some thorough brake inspections on the remaining cars and any others in the roster.

    This should prove interesting.
     

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