I "suspect" the findings will be that not enough hand brakes were applied. I've read that 5 locomotives and 10 cars had their hand brakes set. They are independent of the air system.
Bruce
Train - hazardous cargo "accident"
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I "suspect" the findings will be that not enough hand brakes were applied. I've read that 5 locomotives and 10 cars had their hand brakes set. They are independent of the air system.
Bruce
It's been a while, so I may not have this right.....
There was a minor fire on the parked active locomotive, so the FD and/or a rail employee shut the locomotive down. Apparently standard procedure when responding to a locomotive fire.
With the engine down, air pressure would drop. If all the "regular" air brakes on the train are designed to automatically apply with low pressure, I can't see the train rolling away like it did. Same goes for the other earlier runaway train in Quebec.
Yes, too few manual brakes are cited as the cause for the roll-away, but the recent personal conversation I had leaves me puzzled about train air-brake design.
Rgds, D.
There was a minor fire on the parked active locomotive, so the FD and/or a rail employee shut the locomotive down. Apparently standard procedure when responding to a locomotive fire.
With the engine down, air pressure would drop. If all the "regular" air brakes on the train are designed to automatically apply with low pressure, I can't see the train rolling away like it did. Same goes for the other earlier runaway train in Quebec.
Yes, too few manual brakes are cited as the cause for the roll-away, but the recent personal conversation I had leaves me puzzled about train air-brake design.
Rgds, D.
I think enough hand brakes were applied but the other issues such as the Engine fire and subsequent shutdown of the Robotic Locomotives by accident no doubt had a lot to do with the runaway.
If the one man crew Engineman/Conductor had put 15 handbrakes on the rail cars and only 1 on an engine and the train sat secure he would have been under investigation by the company for delaying the train as the person coming on duty to relieve him would have to go and undo what he did a real catch 22 but thats a railroad reality as "these wheels must turn"
The disaster in Quebec was the Perfect Storm that same method of securement had gone on for months and months and nothing happened but when it did....
If the one man crew Engineman/Conductor had put 15 handbrakes on the rail cars and only 1 on an engine and the train sat secure he would have been under investigation by the company for delaying the train as the person coming on duty to relieve him would have to go and undo what he did a real catch 22 but thats a railroad reality as "these wheels must turn"
The disaster in Quebec was the Perfect Storm that same method of securement had gone on for months and months and nothing happened but when it did....
Yes, I think that was the gist of my buddy's point.
Guessing.... but maybe the rail rationale is they don't want to have just one car spring a leak and be dragged along with all it's wheels locked up. With the high rolling staff levels of days of olde, the idea of an entire train rolling away was probably not considered as likely.
Rgds, D.
Sounds like Profit Before Safety, to me. Rail is hardly the only industry guilty of same.
Playing the odds, cutting corners...... has some interesting reinforcement patterns for people. I draw a parallel with driving drunk - just because somebody gets away with it, doesn't mean that the behaviour should be repeated.
Just heard on CBC, another significant derailment in NB......
Wapske derailed train on fire, carrying propane, crude oil - New Brunswick - CBC News
In another area of society the question gets posed "Who shall police the Police ?". In the area of this thread, I have the impression that Rail is only lightly policed, at best. These last paragraphs are from the end of the linked article.
A CBC investigation into rail safety revealed that CN Rail did not report to authorities more than 1,800 derailments and accidents, including 44 on key rail arteries.
One of those derailments occurred in Plaster Rock which was one of two incidents that prompted the Transportation Safety Board to seek a summons ordering CN to turn over all accident records.
Rgds, D.
aczlan
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Correct. A truck has spring applied brakes that release with air pressure. When you run out of air, you stop.
A train has air applied/released brakes. When you run out of air, you don't stop.
Aaron Z
At the risk of understating the obvious, I don't consider the train design to be Fail Safe.
When I consider what is imposed on trucking, and that I can't put the lightest car made on the road w/o a secondary redundant driver actuated E brake system, I think I'm being fair when saying that Rail gets away with things no other transport sector can.
With an engineer in the cab, yes, I get that a train can dissipate energy w/o working brakes - but you can make the same argument with a car. Still, you wouldn't get past a Safety Check on a car here, w/o a working Ebrake.
With people mostly buying automatics here, it doesn't get used that way much, but one of the design goals for Ebrakes on cars/light trucks is to secure it quickly when Parked. I find it troubling that the lightest vehicles in common use are mandated to have this requirement in place, but not the heaviest high speed machinery in use - Rail.
Yeah.... I get that it's all about Cost Containment/Reduction...... I'm not particularily a fan of lawyers in general, but I hope that some major lawsuits are won against the rail co's, for negligence. The government seems to be doing about as much disciplining of the rail co's as the parents were of the "affluenza" idiot that was recently in the news.
Rgds, D.
crazyal
Super Member
Train brakes are just an advancement over what trains originally had, brakemen. Each car had a man on top of them that would manually apply the brakes when the engineer yelled to them. This, of course had many problems. Between men falling off the train and not hearing the commands trains were vary dangerous. The air bake system was never designed to set or release a parking brake. Labor was cheap so it was assumed that men would just set them as needed.
Trains only have one common airline. That airline serves two duties, first it fills a tank on each car. That tank provides the braking power. The second is to overcome the pressure in the tanks to release the brakes. The final piece of the puzzle is a valve that senses pressure in the common air line. If there's no pressure then the valve opens the line between the pressure tank to the brakes. When there is air the valve closes so the air can't leak out of the pressure tank and bleeds off the brakes. The system works well because the same pressure needed to release the brakes also fills the tank through a check valve. The system doesn't work well because if their are any leaks in the car then the pressure in the tank bleeds off. If the check valve fails to let air into the pressure tank then you have no braking ability at all.
A truck air brakes have a spring in each actuator on the rear wheels. When there is no air the spring applies the brakes. When a driver wants to move they push a parking brake release button and air is applied to the other side of a diaphragm that counters the spring pressure. It takes about 40 psi to over come the spring. After that a second air line connects to another diaphragm that applies the brakes. This system takes two airlines, one to release the brakes, the other to apply the brakes. Secondly the spring's force is much less than the amount of force the air line applies.
A truck weighs a fraction of what a loaded train car could weigh. Any new system would have to be designed to that the spring could apply enough force to hold the train from moving yet be countered by the air from the locomotive. If the brakes on a trailer fail the driver knows pretty quickly and is trained to pull off the road. If one rail car fails it would be impossible for the engineer to know. A stuck brake could cause serious problems. It would overheat and could cause a fire. It could send enough heat to the wheels bearing and cause it to fail. Worse case it could cause a derailment. As it is sticking brakes are an issue with trains so any new system couldn't make it worse. Any new system would have to work with the infrastructure of the current system or a massive upgrade would be needed.
I know there have been attempts to transform to an electric pneumatic system that would use an electrical signal to apply the brakes but I think they were focused on train braking while in motion, not upgrading to an automatic parking brake system.
Trains only have one common airline. That airline serves two duties, first it fills a tank on each car. That tank provides the braking power. The second is to overcome the pressure in the tanks to release the brakes. The final piece of the puzzle is a valve that senses pressure in the common air line. If there's no pressure then the valve opens the line between the pressure tank to the brakes. When there is air the valve closes so the air can't leak out of the pressure tank and bleeds off the brakes. The system works well because the same pressure needed to release the brakes also fills the tank through a check valve. The system doesn't work well because if their are any leaks in the car then the pressure in the tank bleeds off. If the check valve fails to let air into the pressure tank then you have no braking ability at all.
A truck air brakes have a spring in each actuator on the rear wheels. When there is no air the spring applies the brakes. When a driver wants to move they push a parking brake release button and air is applied to the other side of a diaphragm that counters the spring pressure. It takes about 40 psi to over come the spring. After that a second air line connects to another diaphragm that applies the brakes. This system takes two airlines, one to release the brakes, the other to apply the brakes. Secondly the spring's force is much less than the amount of force the air line applies.
A truck weighs a fraction of what a loaded train car could weigh. Any new system would have to be designed to that the spring could apply enough force to hold the train from moving yet be countered by the air from the locomotive. If the brakes on a trailer fail the driver knows pretty quickly and is trained to pull off the road. If one rail car fails it would be impossible for the engineer to know. A stuck brake could cause serious problems. It would overheat and could cause a fire. It could send enough heat to the wheels bearing and cause it to fail. Worse case it could cause a derailment. As it is sticking brakes are an issue with trains so any new system couldn't make it worse. Any new system would have to work with the infrastructure of the current system or a massive upgrade would be needed.
I know there have been attempts to transform to an electric pneumatic system that would use an electrical signal to apply the brakes but I think they were focused on train braking while in motion, not upgrading to an automatic parking brake system.
