http://news.yahoo.com/train-carrying-petroleum-derails-catches-fire-canadas-quebec-121417580.html
A driverless freight train. That one is going to take some explaining, one would think.
TOC
From the reports I read, I got that the cars were uncoupled, and rolled downhill into the town.
Help me with my ignorance, but, I thought that the brakes would engage with out “Air in the lines”.
Is this wrong, or were the engines still coupled?
The BBC report said the locos were found a ways away.
So many things that are never supposed to happen happened.
Dave Taylor said:
From the reports I read, I got that the cars were uncoupled, and rolled downhill into the town.
Help me with my ignorance, but, I thought that the brakes would engage with out “Air in the lines”.
Is this wrong, or were the engines still coupled?
Dave,
Under normal conditions, yes if the train line was ‘charged’ (ie air in the line) the brakes should have set. But if the train was off air the brakes bled off after so many hours.
Not sure really what happened here, but I’ll tell you a similar story that happened to me.
I pulled my train into a yard one evening, set the brakes (20 lb set). The conductor when back and set a couple of hand brakes. We then uncoupled the locomotives and the train dumped into emergency. The conductor then put the train on yard air (thus recharging the system so that if it moved the train line would dump) and we left. At this point the train was being held in place with handbrakes. The train was 75% on a SB grade, 25% NB grade. 24 hours later I get a phone call from the terminal manager asking me if I knew how many handbrakes the conductor set.
The train mysteriously lost the air, and then proceeded to roll NB out of the yard. The train rolled through a bunch of crossings and finally came to a stop about 5 miles later.
My conductor and I got the blame because we where the last crew to ‘touch’ the train even though we had been off the train for over 12 hours (I was actually in a different terminal getting my federal rest when I got the phone call).
But the truth never came out (officially)…
After we dropped the train off, a yard crew the next day (12-18 hours later) was called to spot the train to the final terminal 20 miles away. But before they took the train they had to switch a few cars out. They pulled the train to the N end of the yard (were switching was much easier), bottled the air (closed both angle cocks so the train doesn’t dump), and released the handbrakes. After waiting a while they got new instructions and left the yard…
Mysterious the train rolled out the N end… The crew that stopped the train claimed that the angle cock was closed on the N end, and open on the S end (the end we uncoupled away from). Meanwhile 75% of the train had to roll up hill to get out of the yard…
So my conductor and I got blamed for not setting enough handbrakes, but the handbrakes we set held the train for over 12 hours before it mysteriously moved (around the same time that the train was scheduled to be delievered to the recieving terminal).
Needless to say I’m not sure what happened in Canada but something similar could have happened. Or someone closed the angle cock next to the power and pulled the pill…
One more reason when you stop a train to have the slack stretched out. Or the knuckle could have broken, but then the air would have dumped. But depending on how long the train sat uncoupled the air could have bled off, and caused a run away if not enough brakes were set.
Craig
The rules read a sufficinent # of handbrakes are to be set, but nowhere is there a definition as to the percentage of the train needs to be set. tonight i knucked on to a locomotive with its hand brakes set and it moved relatively freely once motion is imparted. most folks out there in the railroad industry do not often set enought handbrakes because they are apt to catch it from the next crew to do the pickup when they find 1/4 of the train or more setup. then start to deal with the dymamics of when the air reservoirs are finally bleed dry many hours after a dump is made and the slightest movement of a single car will set up a chain reaction to get a cut of cars moving and overcome the three cars the handbrakes were set on. the railroad industry needs to better defign to its T&E folks what percentage of the train needs to be set rather than the language “sufficient”
Al P.
Ah but ‘sufficient’ leaves it open to interpretation! 
The only spot that the rule book tells us to tie down a exact percentage is on the mountain grade. 100% But there’s a chart in the ABTH (BNSF) that is the recommended number per grade and tonnage. But I’ve found once you work the territory enough you learn what is ‘sufficient’ really fast.
The ABTH also says that the engineer is supposed to release all the air after the brakes are tied to ensure that the hand brakes hold the train. Then recharge and make the 20 lb set. After the thing that happened to me, the Road Foreman started to pull the tapes of random trains to make sure the engineers were doing such.
Al Pomeroy said: the railroad industry needs to better defign to its T&E folks what percentage of the train needs to be set rather than the language “sufficient”
The language is vague by design
If the train moves, an insufficient number of brakes were set…their employee is at fault.
If they set a percentage in the rules and the train still moves…their procedures and rules are at fault.
Ralph
Hi Guys:
I always thought that railroad passenger car and freight car brakes operated on the
" air over spring " design in the same manner as hwy tractor trailors.
Given the magnitude of this disaster:
-
I can see new Canadian regulations requiring hazardous freight to be stored in a monitored environment
-
the return to the direct monitoring of Canadian Rail Operations by Transport Canada
Simply a terrible situation that never should have occurred.
Norman
I always thought the whole purpose of having air brakes on trains, was that if it loses air for any reason, the brakes would set. Is this not correct?
Ray Dunakin said:
I always thought the whole purpose of having air brakes on trains, was that if it loses air for any reason, the brakes would set. Is this not correct?
Ray, yes that is correct.
However, you’re overlooking the fact that after the brakes are set by a reduction of air pressure in the train brake line. I’m pretty sure that the Aux reservoir on each car is cut off from the train brake line, and supplies air pressure to the brake cylinders on that one car to keep the brakes set.
Now if you had a perfectly air tight system (i.e. no air leaks) on each car then the brakes would remain set, but all of the individual cars have air leaks and bleed down over time, and in turn release their brakes. Thus the need to set a “sufficient ???” number of hand-brakes on a given train of cars to hold it immobile indefinitely.
40 still missing in deadly Canada train crash, fire , strange looks like all the wheels are off the tank cars http://news.yahoo.com/40-still-missing-deadly-canada-rail-crash-fire-005901210.html
Richard
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Steve Conkle said:
Ray Dunakin said:
I always thought the whole purpose of having air brakes on trains, was that if it loses air for any reason, the brakes would set. Is this not correct?
Ray, yes that is correct.
However, you’re overlooking the fact that after the brakes are set by a reduction of air pressure in the train brake line. I’m pretty sure that the Aux reservoir on each car is cut off from the train brake line, and supplies air pressure to the brake cylinders on that one car to keep the brakes set.
Now if you had a perfectly air tight system (i.e. no air leaks) on each car then the brakes would remain set, but all of the individual cars have air leaks and bleed down over time, and in turn release their brakes. Thus the need to set a “sufficient ???” number of hand-brakes on a given train of cars to hold it immobile indefinitely.
I think you might be reading past him Steve.
I too was under the mistaken impression that if you bled air out of the system the brakes would be applied. I assumed it was the PRESENCE of air pressure that allowed the car to roll…No air pressure = no movement. Apparently this is not true.
Lauzon, the fire chief, said firefighters in a nearby community were called to a locomotive blaze on the same train a few hours before the derailment. Lauzon said he could not provide additional details about that fire since it was in another jurisdiction. McGonigle confirmed the fire department showed up after the first engineer tied up and went to a local hotel. Someone later reported a fire.
“We know that one of our employees from our engineering department showed up at the same time to assist the fire department. Exactly what they did is being investigated so the engineer wasn’t the last man to touch that train, we know that, but we’re not sure what happened,” McGonigle said.
Sabotage?
Since the train was parked unlocomotived and unmanned,
Maybe kids messing with air valve.
Mark V said:
Steve Conkle said:
Ray Dunakin said:
I always thought the whole purpose of having air brakes on trains, was that if it loses air for any reason, the brakes would set. Is this not correct?
Ray, yes that is correct.
However, you’re overlooking the fact that after the brakes are set by a reduction of air pressure in the train brake line. I’m pretty sure that the Aux reservoir on each car is cut off from the train brake line, and supplies air pressure to the brake cylinders on that one car to keep the brakes set.
Now if you had a perfectly air tight system (i.e. no air leaks) on each car then the brakes would remain set, but all of the individual cars have air leaks and bleed down over time, and in turn release their brakes. Thus the need to set a “sufficient ???” number of hand-brakes on a given train of cars to hold it immobile indefinitely.
I think you might be reading past him Steve.
I too was under the mistaken impression that if you bled air out of the system the brakes would be applied. I assumed it was the PRESENCE of air pressure that allowed the car to roll…No air pressure = no movement. Apparently this is not true.
Yes and no…
The air brakes work when you remove air from the system. A normally charged brake line is 90psi, and when you stop you make increasing amounts of sets that drop the air pressure from 90 psi down to about 75 psi(min 5-7 lb reduction, full service, and emergency). The actual mechanical forces at work to hold each individual brake on the train car requires having a reservoir full of air to apply the brakes. So when the train goes into emergency the main res and emergency res on each car have ‘air’ but the train line is empty. In theory (if no leaks exist) this should hold the car for a period of time. As soon as the air bleeds down (leaking from the reservoir) the brakes release.
This is why you can’t rely on the air brakes to hold a train. You have to tie a ‘sufficient’ number of hand brakes to hold.
Richard - Thanks for posting that link. Photos on that page do a good job helping me get my head around the quick blow-it-off reports on US network TV news last night ‘Train derailment levels Canadian town’. While the damage is extensive and tragic, the town was far from leveled.
What I can’t quite figure out from the pictures is what caused the derailment to take place at that spot. The curvature isn’t particularly sharp. Maybe an impact with a parked rail car or perhaps a grade crossing impact.
EDIT to add: Looking at Google satellite view; there are a number of switches just beyond the grade crossing and a small yard. Depending on normal alignment of the switches, there could be a significant curve, or a more gentle one at that spot.
Ralph Berg said:
Al Pomeroy said: the railroad industry needs to better defign to its T&E folks what percentage of the train needs to be set rather than the language “sufficient”
The language is vague by design
If the train moves, an insufficient number of brakes were set…their employee is at fault.
If they set a percentage in the rules and the train still moves…their procedures and rules are at fault.
Ralph
Given that situation, the prudent “Rail” would set 100% of the brakes, knowing that the suits did not have his back.
Steve Featherkile said:
Ralph Berg said:
Al Pomeroy said: the railroad industry needs to better defign to its T&E folks what percentage of the train needs to be set rather than the language “sufficient”
The language is vague by design
If the train moves, an insufficient number of brakes were set…their employee is at fault.
If they set a percentage in the rules and the train still moves…their procedures and rules are at fault.
RalphGiven that situation, the prudent “Rail” would set 100% of the brakes, knowing that the suits did not have his back.
Steve,
Have you tied any brakes? They take a long time. When a train stalls on the hill (Stevens) it takes the conductor anywhere from 3-4 hours to tie the train down in good weather.
You learn the territory after a few months, knowing what will hold a train and what wont.
There’s also a difference between a tight hand brake and a loose hand brake. Both are technically ‘tied’ but one has a much better holding power. So I could tie 10 loose brakes or 5 extra tight ones, both being “sufficient” to hold the train.
Craig
Craig Townsend said:
Steve Featherkile said:
Ralph Berg said:
Al Pomeroy said: the railroad industry needs to better defign to its T&E folks what percentage of the train needs to be set rather than the language “sufficient”
The language is vague by design
If the train moves, an insufficient number of brakes were set…their employee is at fault.
If they set a percentage in the rules and the train still moves…their procedures and rules are at fault.
RalphGiven that situation, the prudent “Rail” would set 100% of the brakes, knowing that the suits did not have his back.
Steve,
Have you tied any brakes? They take a long time. When a train stalls on the hill (Stevens) it takes the conductor anywhere from 3-4 hours to tie the train down in good weather.
You learn the territory after a few months, knowing what will hold a train and what wont.There’s also a difference between a tight hand brake and a loose hand brake. Both are technically ‘tied’ but one has a much better holding power. So I could tie 10 loose brakes or 5 extra tight ones, both being “sufficient” to hold the train.
Craig
I’ve never tied any brakes…But then again I’ve never burned 40 people to death either. Not being deliberately provocative, but when industry kills this many we need to evaluate what is good for the public and what’s good for profit. At the very least a thorough review of procedures and equipment design are required. Perhaps an additional conductor is required to bring down the time it takes.
In this incident, current procedures or equipment were insufficient to stop a significant amount of loss to life and property.