1754 replies to this topic

[Mike K.]

Good question. Details are being withheld from the reports I've read so far. We know the train rolled, we know there was a big bang, but the how and why hasn't been disclosed.

[VicHockeyFan]

Good question. Details are being withheld from the reports I've read so far. We know the train rolled, we know there was a big bang, but the how and why hasn't been disclosed.

Reports say the engines (5 of them) disconnected from the tankers 800m or so before the derailment. That seems a little odd too. Maybe the tankers were trying to brake, but the 5 engines were under full or partial power. But I'm unclear where those engines are now, I don't see any in the wreckage. Some reports said the train company was able to grab some of the last tankers that were not derailed, and pull them back away from the mess, back up the hill. Now, they could have brought in an engine from some distance to do that. I don't see any situation where the 5 engines would have been on the back end of the runaway. You never push cars at any good speed, especially tankers. You'd always be required to pull them.

[VicHockeyFan]

I thought these systems had to be operating with pressure in the lines for the brakes to be unapplied. So for example a parked semi-trailer will always have its brakes fully applied because the air pressure systems is not operating so there is zero PSI in the lines. If the air pressure in the system fails, the brakes are automatically applied to maximum pressure.

Cars (*not sure about engines) can always be moved around with no air hooked up to them, that's what you do when shunting them around in the yard. Yards are generally flat-ground places, where you can safely move stuff around, and not have to bother hooking up and unhooking air lines with every move. So there certainly is some way to turn off the fail-safe braking in that situation.

*Engines can also be strung in a line of cars and engines, and be turned off, not under power, and just glide. This happens all the time when one engine malfunctions, you just turn it off and rely on the remaining engines. Might have to go a bit slower. But in this case they'd still generally be hooking into the air system.

[VicHockeyFan]

It's also confirmed there was a fire on one locomotive earlier that night. Everything is pointing to a series of mishaps, often what we see in this type, or air disasters.

From a railroad forum:

As I understand it, the MM&A (railway company) had an engineering(track/MOW) employee on hand to aid the fire department (the earlier fire).

The bigger question is not about the airbrakes holding the train but was it properly secured with the proper number of handbrakes and was a roll away test performed with the train and locomotive brakes released to insure the hand brakes would hold the train if and when the air leaked off. This is of course unless the train had at least one locomotive left running to keep the air charged up in the train line with air brakes fully applied to hold it. Regardless, the required number of handbrakes needed to hold the train stationary should have been (and maybe was) applied. No matter, all discussion about this incident is just speculation until the fire is out and the investigation completed.

Barry

[eseedhouse]

It's also confirmed there was a fire on one locomotive earlier that night. Everything is pointing to a series of mishaps, often what we see in this type, or air disasters.

I believe I saw one story on CBC that said at least one engine detached from the cars and continued past the accident site and was found out of town still on the track. Perhaps my memory is faulty.

What surprised me about the news coverage is that only now do they seem to be covering what went on at the site the train was supposedly parked at. CBC Newsworld just reported that there was a fire in one of the engines that was put out by the fire department at the parking site. The engines were turned off after the fire was put out, indicating that they were running prior to that. I don't know enough about how trains are managed to know if this was or was not standard procedure. But why wasn't a reporter sent to the parking site the same day as the reporting about the explosion started?

[VicHockeyFan]

This does not make sense.

http://www.thestar.c..._explosion.html

Ed Burkhardt, chairman of the Montreal, Maine & Atlantic Railway, said Sunday night that the train’s sole engineer shut down four of the five locomotive units on the train, as is standard procedure, in the neighbouring community of Nantes before heading to Lac Mégantic to sleep. Burkhardt said the next engineer was probably due to arrive at daybreak.

But someone managed to shut down the fifth locomotive unit, he said. The railroad alleges someone tampered with the controls of the fifth engine, the one maintaining brake pressure to keep the train stopped.

“If the operating locomotive is shut down, there’s nothing left to keep the brakes charged up, and the brake pressure will drop finally to the point where they can’t be held in place any longer,” Burkhardt said.

There are two ways to shut down the fifth unit: There’s an emergency lever on the outside of the locomotive that anyone wandering by could access. Or, there are a number of levers and buttons inside the unlocked cabin.

Both means were used, said Burkhardt. Surely this is not the only safety system - VHF

The result was what Prime Minister Stephen Harper, who visited the stricken Eastern Townships community Sunday, said resembled a “war zone.”

The chair of the 10-year-old rail company headquartered in Maine said they would “consider” changes to procedures in light of the tragedy.

Burkhardt said the engineer went to the epicentre of the explosions and picked up nine cars, bringing them back to Nantes, where they still sat on the tracks beside the road Sunday.

In a much earlier report, Ed Burkhardt said that only the engineer would have the means to set the train in motion, that he was in charge of whatever security/safety measures were in place.

How did the engineer get from Nantes to the crash site? Maybe there is extra engines kept there. EDIT: Nantes map. Indeed there does appear to be a siding just east of Nantes town centre, that could hold extra trains.

[Bingo]

Ravaged site is now being treated as a “crime scene”.

[eseedhouse]

The Lac-Megantic Public Library was one of the buildings wiped off the map. Now for me, that makes it personal.

[VicHockeyFan]

I thought trains had air brake systems like tractor trailers where the brakes are normally in the applied position by springs and are released only when there is enough air pressure in the system to overcome the force exerted by the springs?

No, apparently not.

http://www.tarorigin.com/art/Jbentley/

Freight train brake systems have not changed in basic operation since the 1930's. They are controlled and actuated by compressed air. For those tempted to think that train brakes operate the same way as large truck brakes read on. You might be surprised.

Each power unit (locomotive) has an air compressor that supplies air for the entire train's braking system. A feed valve in the locomotive regulates the desired pressure that is supplied to remainder the train. This pressure must be at least 70 psi (although most modern systems use 90 psi). A "brakepipe" runs the full length of the train. The brakepipe carries the compressed air from the control unit to the rest of the train. Unlike truck brakes (and passenger train brakes for that matter) this single source of air carries both the air that powers the brakes as well as the signal to control them.

So... when the air is on, they charge individual tanks on each wagon, can take 8 or 10 minutes to charge a whole long train. Then the way they activate the brake is actually by reducing air pressure in the main brake line. So this is the "failsafe" if a hose severs somewhere down the line of wagons, of the train breaks apart.

But these brakes need to be "charged" first on train start-up, or kept charged by running one engine all the time.

[VicHockeyFan]

More strange news:

There’s confusion about the sequence of events that led to this catastrophe. The train — in this case with five locomotives and about six dozen oil tankers — was stopped for the night in Nantes, about 12 kilometres uphill from Lac-Mégantic, just before midnight Friday. The sole engineer aboard the Montreal, Maine & Atlantic (MMA) Railways train says he turned off all but one of the locomotives, left running to power the air brakes, before heading to a hotel in nearby Lac-Mégantic.

Shortly thereafter, a fire broke out on the unattended locomotive. Local fire crews apparently shut down the running engine, extinguished the fire and left. The train, no longer braked, apparently began rolling down the tracks towards Lac-Mégantic, picking up momentum before derailing in the centre of the town.

Why was a train with such a dangerous cargo left parked, unattended, uphill of a community? Further, why didn’t anyone perceive that relying on just one locomotive’s set of brakes — which apparently can be shut off by anyone walking past the engine — provided paper thin, at best, protection against a potential catastrophic accident?

The local fire chief said firefighters spoke to company representatives before leaving the scene but claimed brakes were not discussed. If that’s accurate, why not?

http://thechronicleh...gantic-disaster

The sole engineer? Surely more than one person is a responsible for a train of this size and cargo makeup. Do they mean there was one engineer, and one or two lower-classed employees? I wonder why they leave it in Nantes, if the engineer goes to sleep in Lac-Magantic?

[Bingo]

If there was a fire, was it set to cover up traces of a crime?

Were the tanker cars on a main line or on a siding. Upon checking Google Maps, there looks to be a long stretch of siding. If the train was parked on the siding wouldn't the switch have to be open to allow the cars to roll away down the 12km of track to Lac-Megantic?

[VicHockeyFan]

http://www.reuters.c...E96505L20130708

(Reuters) - Airbrakes that would have prevented the Quebec train disaster failed because they were powered by an engine that was shut down by firefighters as they dealt with a fire shortly before the calamity occurred, the head of the railway that operated the train said on Monday.

The runaway oil tanker train derailed in Lac-Megantic shortly after one o'clock in the morning on Saturday, exploding in a deadly ball of flames and killing at least five people, with another 40 still missing and feared dead.

The train had been parked at a siding on a slope near the town of Nantes, which is 12 km (8 miles) west of Lac-Megantic. The volunteer Nantes fire service was called out late on Friday night to deal with an engine fire on one of the train's locomotives.

Nantes Fire Chief Patrick Lambert told Reuters the crew had switched off the engine as they extinguished a "good-sized" blaze in the engine, probably caused by a fuel or oil line break in the engine.

The problem was that the engine had been left on by the train's engineer to maintain pressure in the air brakes, Ed Burkhardt, chairman of Montreal, Maine & Atlantic Railway (MMA), said in an interview. As the pressure gradually "leaked off", the air brakes failed and the train began to slide downhill, he said.

The fire service said it contacted a local MMA dispatcher in Farnham, Quebec, after the blaze was out. "We told them what we did and how we did it," Lambert said.

Asked whether there had been any discussion about the brakes, he replied: "There was no discussion of the brakes at that time. We were there for the train fire. As for the inspection of the train after the fact, that was up to them."

Andre Gendron, 38, lives on a wooded property next to the rail yard in Nantes. He said he was burning a campfire outside his trailer on Friday night when he heard the fire trucks.

"About five minutes after the firemen left, I felt the vibration of a train moving down the track. I then saw the train move by without its lights on," Gendron told Reuters.

"I found it strange its lights weren't on and thought it was an electrical problem on board. It wasn't long after that I heard the explosion. I could see the light from the fires in Lac Megantic."

[VicHockeyFan]

Were the tanker cars on a main line or on a siding. Upon checking Google Maps, there looks to be a long stretch of siding. If the train was parked on the siding wouldn't the switch have to be open to allow the cars to roll away down the 12km of track to Lac-Megantic?

When you leave a siding and return to the main line, the train wheels force the switch regardless of how it's set, you go back onto the main line (sometimes with damage to the switch, sometimes not). But you don't derail, generally.

[eseedhouse]

http://www.reuters.c...E96505L20130708

If they left the train on a slope relying on a single engine to keep running to prevent a runaway that's just plain stupid. At the very least there has to be a backup to prevent runaway. Or hey? How about not parking it on a hill?

Or would that cost too much money?

[VicHockeyFan]

If they left the train on a slope relying on a single engine to keep running to prevent a runaway that's just plain stupid. At the very least there has to be a backup to prevent runaway. Or hey? How about not parking it on a hill?

Or would that cost too much money?

Something is not right here. I'll venture to say that in addition to leaving the engine on you MUST have a secondary way to prevent movement, on even the lightest slope. This must be railroad law. Now, on that stretch, maybe it means you have to go set 30 hand-brakes. That would be a hassle.

Virtually all railroad rolling stock is equipped with manually operated mechanical hand brake devices that set and release the brakes. Most of these involve a chain linked to the brake rigging, most often at the brake cylinder, that when tightened pull the piston out against the releasing springs, thus applying the brakes on the car (if there is only one brake cylinder per car) or bogie (if there is more than once cylinder per car). Newer locomotives have electric systems that simply place an electric motor in place of the chain winding mechanism. This brake acts independent of the action of the automatic air brakes, which function collectively when coupled in a train and are under the control of the locomotive engineer.

Manual hand brakes serve to keep a piece of rolling stock stationary after it has been spotted in a rail yard or at a customer for unloading or loading. They are also used to secure a parked train from inadvertent movement, especially while unmanned.

http://en.wikipedia....oad_hand_brakes

[Bingo]

A bit off topic, but one of my favourite wartime movies is "The Train" with Burt Lancaster, if you want to see some sabotage.

[VicHockeyFan]

How much do you want to bet the Nantes Volunteer Fire department knows a lot about railway brakes - today.

[Bingo]

If they left the train on a slope relying on a single engine to keep running to prevent a runaway that's just plain stupid. At the very least there has to be a backup to prevent runaway. Or hey? How about not parking it on a hill?

Then there is the dead man's switch on the locomotive that stops the train if the engineer takes his foot off the pedal during a heart-attack, or if he is otherwise distracted while performing his duties. But I suppose you can just put a brick on it if you need to go to the bathroom, of get a hotel room. Nope, probably doesn't apply in this case.

[VicHockeyFan]

^ I think all newer trains use an alerter. Harder to override.

[eseedhouse]

How much do you want to bet the Nantes Volunteer Fire department knows a lot about railway brakes - today.

If they didn't know, if every fire department in every town along a railway doesn't know, then it's time to pile some serious fines on the railways that don't make sure they do.