Major Train Derailment in Tulsa

[sgrizzle]

http://www.news9.com/story/24215303/vandalism-suspected-in-tulsa-train-derailment

[AngieB]

Not saying it *wasn't* vandalism, but saying it was is pretty convenient, don'tcha think?

[BKDotCom]

Not saying it *wasn't* vandalism, but saying it was is pretty convenient, don'tcha think?

Next time I screw up at work I'm going to play the sabotage card.

[cannon_fodder]

One article said airbrakes were tampered with (World), this indicates the coupler.

Here is the odd thing:  as I understand it each car has independent air brakes.  Air brakes are, by default ON.  They require activation (air) to be released.  If they are destroyed, then they would lock.

Maybe this principle doesn't apply to trains?

[AquaMan]

One article said airbrakes were tampered with (World), this indicates the coupler.

Here is the odd thing:  as I understand it each car has independent air brakes.  Air brakes are, by default ON.  They require activation (air) to be released.  If they are destroyed, then they would lock.

Maybe this principle doesn't apply to trains?

Even busses and trucks prior to 1978 did not have the feature you refer to, known as spring brakes. When the air pressure drops, the spring brake engages and locks up the brakes. However, according to my old truck driver friends, when there is no air pressure on pre 78 vehicles, the brakes simply fade, then don't work at all. Truck drivers had to constantly monitor air pressure and utilize gears. I have experienced this with a an old air brake bus. I suspect that rail cars don't automatically lock up or that they aren't strong enough to hold the momentum of a 225,000 pound moving freight car.

[AquaMan]

Not saying it *wasn't* vandalism, but saying it was is pretty convenient, don'tcha think?

One of my friends is an old train guy who worked this area for his entire career. I will check with him to see if he finds it credible. I will say, these train guys are very well trained and take their jobs seriously. Slowly, and seriously.

[Breadburner]

Being a Conductor or Engineer is no joke.....BNSF is a first class outfit.....

[Red Arrow]

I don't know how this applies to a set of cars disconnected from the rest of the train.


The straight air brake
The first form of the air brake consisted of an air pump, a main reservoir (pressure vessel), and an engineer's valve on the locomotive, and of a train pipe and brake cylinder on each car. One problem with this first form of the air brake was that braking was applied to the first cars in a train much sooner than to the rear cars, resulting in shocks and damages when the rear cars bunted against the cars ahead of them.
The main objection, however, was that it was not an automatic brake, i.e. even a minor mishap like a broken coupling left the entire train without any brake power at all.

The plain automatic air brake
In 1872, George Westinghouse invented the automatic air brake by inventing the triple valve and by equipping each car with its own air cylinder. Air pressure is maintained in the auxiliary reservoirs and in the train pipe at all times when the brakes are not applied. An equilibrium of air pressure is maintained in the train pipe and in the auxiliary air cylinders.
To apply the brakes to all of the cars at about the same time, pressure is released from the train pipe, causing the triple valve on each car to apply the brakes. To release the brakes on each car, pressure is increased in the train pipe until an excess pressure above that of the pressure in each auxiliary cylinder is reached, which throws the triple valve so as to close the inlet to the brake cylinder and open the inlet to the auxiliary reservoir from the train pipe, thus allowing the equilibrium of the two pressures to be reached.

The quick action triple valve
Although the plain automatic air brake was a great improvement over the straight air brake, in an emergency the system still applied the brakes to the last cars in a train later than to the first cars in a train. To remedy that condition, George Westinghouse invented the quick action triple valve in 1887. It automatically vents air from the brake pipe locally on each car, which applies the brakes more quickly.

http://en.wikipedia.org/wiki/Westinghouse_Air_Brake_Company

[Red Arrow]

Even busses and trucks prior to 1978 did not have the feature you refer to, known as spring brakes. When the air pressure drops, the spring brake engages and locks up the brakes. However, according to my old truck driver friends, when there is no air pressure on pre 78 vehicles, the brakes simply fade, then don't work at all. Truck drivers had to constantly monitor air pressure and utilize gears. I have experienced this with a an old air brake bus. I suspect that rail cars don't automatically lock up or that they aren't strong enough to hold the momentum of a 225,000 pound moving freight car.

I was a volunteer fireman near Philadelphia, PA in the late 60s. I remember that the air tanks had to be charged to have brakes in the trucks.  Qualified members would start the trucks engines to charge the air tanks while still in the firehouse if the trucks hadn't been on a call lately.

[AquaMan]

You can over ride an air brake on a truck or bus with enough horsepower or momentum. I have done that. Pulling the air brake knob does not immediately stop the vehicle, it applies the brakes to slow the vehicle until it stops. Otherwise the vehicle would lock up and slide.

Railroad cars may be different. I am surprised at their complexity. Lends credence to the assertion that it was likely sabotage by someone knowledgeable.

[Red Arrow]

I found this site describing train brakes.

http://www.sdrm.org/faqs/brakes/history/

[patric]

There was talk of releasing surveillance photos, but all we have seen sofar is a blurry cellphone picture someone took of the backs of two people walking along railroad tracks.   

[AquaMan]

I drove past the site today near Dawson road and Yale. Its worse than it looked in the paper.

[Conan71]

I drove past the site today near Dawson road and Yale. Its worse than it looked in the paper.

Napalm, land mines and the sort?

[AquaMan]

There were about a dozen box cars mangled up and stacked on top of each other. They appear to be totalled out. Coal creek looked more coal like than usual.
No doubt Obama sent in drones to pay back Inhofe for not going to the real Christmas Parade.