…and you’re operating 2-3 high HP diesels at the head of a mixed manifest train. The train is about 8-9k feet long. The territory you’re operating in has some small hills and curves to the L and R. You are also speeding up & slowing down ~10mph from your ‘average’ speed of 35 mph. How would you tell if you had a derailment towards the back of your train (out of visual range)? Gauge readings? Extra ‘bangs’ that are not associated with slack? I’m just curious. Thanks in advance!
…I’m not an engineer but my thought would be: Wouldn’t the train go into emergency…? {Assuming some cars or one car disconnects}.
Train will go into emergency as soon as the trainline separates. Barring that, it will get harder to pull and the engineer should notice he’s dragging down. Speed is reducing, amperage is increasing.
You won’t necessarily know, trains have been drug sexeral miles before piling up. If the train does not seperate than it won’t go into emergency, if you have one or two wheels off the drag may not be very much especially for a train in the 8-9k foot range. Usually the derailed wheels will find a crossing or switch points or a curve to derail on. Hopefully you find the dragging equipment detector before it gets out of hand.
Again depends on the train makeup, speed, horse power, train tonnage would be a very important factor. If you are in the yard and have 10-12 cars you would probably know right away, 8-9k foot, 10,000 to 15,000 ton train less likely you would know what is going on. Again, depends on a lot of factors. Most likely the train would go into emergency before you realized the train pulling harder.
So it would go into emergency only if the brakeline gets separated and loses pressure?
A car getting jostled enough will usualy get a kicker, where brakevalve gets banged around enough that it goes in emergency, so even if the air hoses hold, chances are train would still go in emergency, but not all the time.
Let’s say a sagging brake hose breaks apart at a high grade crossing and you go into emergency. How can you tell whether it’s that or a derailment?
Or do you know only when the conductor walking back discovers a plume of smoke or dust?
You got it. If you go into emergency, you let everybody know (dispatcher, primarily; also trains that might be traveling on adjacent tracks), then you go and inspect your train. If it was the trainline dynamiting the train and the pressure comes back up, it doesn’t matter–the rule says you go back and inspect.
As has been mentioned, trains sometimes put a couple wheels on the ground and keep going. Sometimes they drag for a distance and then pile up. Many times they drag for a distance, but the problem is detected and the train is stopped before a pileup occurs. I recall seeing an incident like that on the Milwaukee Road, west of Minneapolis, where a car was dragged for several miles, and then the train stopped without any pileup. However, for those several miles, on the outside of one rail, all the spike heads were mashed, all the tie plates were creased, all the angle bars had a corner knocked off, about a quarter of the ties were seriously shattered, and the ballast had been continuously cut and thrown sideways like the action of a snowplow. I suppose there must have been several thousand tons of ballast dislodged and scattered to the side of the right of way over the course of the derailment. And all planked grade crossings got demolished along the way.
There have also been cases of wheels derailing, dragging for a distance, and then re-railing for some reason. In such cases, there is no pileup, the brakes do not go into emergency, and nobody knows about the derailment until track damage is discovered. When derailments spontaneously re-rail, there is usually some specific feature of trackwork that brings it about. Another requirement for this re-railing is that the truck be free of damage, and thus capable of running correctly. Some of those running derailments have been caused by a burnt-off axle, so they could not possibly re-rail.
There have been some cases, particularly at higher speeds, where wheels derailed for no apparent reason, and then re-railed for no apparent reason.
There are also specific features of trackwork that can snag a dragging derailment and cause a pileup. Examples would be switches and at-grade crossings with other railroads.
Perhaps this was not a universal requirement, but when
IIRC, there was a story in Trains not long ago about a car that derailed, then managed to rerail. Were it not for a damaged remote controlled switch, or something like that, it might have been a while before anyone figured out what happened, and what train it happened to.
I think that was a BNSF roadrailer. I have that issue around somewhere. That’s what originally got me thinking of this topic.
How many detectors are around? Are they sparse or is that dependant on the system and route?
Here is a little curioisty from the Railroad Gazette from over 100 years ago. It is one of those cases where an entire truck was ejected from a train and left along the right of way while the train continued on the rails:
November 1896
9th, on Cleveland, Cincinnati, Chicago & St. Louis, near Larue, O., a brake beam of an empty platform car, in the middle of a long westbound freight train, fell upon the track and tore up a crossing plank. This plank was carried along about nine miles when it dropped off and derailed one truck; this truck ran on the sleepers for about half a mile and then ran off clear of the track, the train going on. At the same time that this truck jumped the track one truck of the next following car also went off, and this one ran on the sleepers about 2,000 ft. farther than the other; then it got back on the track and behaved all right. After running about six miles farther the trainmen noticed that they had lost a truck and stopped the train.
I know I should know the answer to my question, as I did ride my terrority once, but…
What is the indication to the engineer, outside of a hotbox-type voice speaking over the radio, that the train is in emergency? Is it a voice actuator, where suddenly you here over the radio, “and you thought your day started out a drag…” or is it an indicator light on the panel?
Tina
Tina, you know, believe me! Your brake pipe pressure suddenly goes from whatever your setting is to zero. And the brakes set up, hard. And the engine goes down to idle due to the PC valve. I have never been on board a locomotive when an undesired emergency application occurred, so I’m not sure it can be heard over all other locomotive noises. But if you’re trackside, there is no mistaking that sound!
Having experienced an emergency application whilst in our passenger cars, as well as an unintentionally stiff service application, I can tell you that you know.
If you’re on the ground, you’ll hear all the cars dumping air.
Carl and Larry,
Thanks for the information. I understand it now.
tina
According to Amtrak Engineer, author and Trains.com contributor Doug Riddell, the loud bang from the brake pipe in the cab will wake one from a sound sleep. The gage showing brake pipe pressure is rapidly heading to zero and the train also start to decelerate at a rapid rate.
The only voice heard is the engineer saying "Ah, s…!
When I was still workins as a switchman we had a car we pulled out of a track on the ground re-rail itself when it went through the frog on the turnout. I hadn’t seen anything like it. As an engineer I have never been on the ground on the main line. However a friend of mine set off a dragging equipment detector indicating an axle near the end of train. He thought there was no way they were on the ground as they didnt feel anything unusual. Well he pulled the rear of the train up to the conductor and sure enough they were on the ground. It was on a garbage train, intermodal cars with containers of trash. Oops.
… the loud bang from the brake pipe in the cab will wake one from a sound sleep. …
Jay, I would have presented my question to the “one-who-reads” but he was sound asleep in front of all those books.
tina
Don’t wake him up, he might correct my spelling of “gage”.
Jay