Longer Trains Cause More Derailments

[charlie hebdo]

You missed the key point of Bucky's post, namely that the doomed train lacked sufficient braking capability.

[Overmod]

charlie hebdo

You missed the key point of Bucky's post, namely that the doomed train lacked sufficient braking capability.

But wasn't a key point at Springfield that there was too much (or more precisely too quickly, or poorly modulated) head-end-only dynamic braking, causing run-in acceleration in part of the lightly-loaded intermediate section of the consist?

 

[tree68]

Overmod

 

charlie hebdo

You missed the key point of Bucky's post, namely that the doomed train lacked sufficient braking capability.

 

 

But wasn't a key point at Springfield that there was too much (or more precisely too quickly, or poorly modulated) head-end-only dynamic braking, causing run-in acceleration in part of the lightly-loaded intermediate section of the consist? 

One could argue that there was too much braking capacity, in the wrong place...

[Euclid]

To Big Jim’s point in the last post of the previous page, I am aware of the fact that rules limit the application of dynamic brakes and also aware of the reason for that limitation.  But I don’t know all the details of those rules.   In any case, everything I stated about the matter is cited from FRA report I linked.  The report raises several questions.  One question is, why did the crew not use the dynamic braking of the mid-train DPU?  Even if they were limited by rules to only use dynamics of two units (as Big Jim says), why use the two head end units?  Why not use one of the head end units and the mid-train unit.  I’ll bet that would have prevented the derailment. 

 

As I understand it, railroads are urging engineers of monster trains to use dynamic braking rather than air braking.  The problem with dynamics is that all of the braking effort comes from retarding the rotation of the wheels of the locomotive applying dynamic braking.  So when this train applied dynamic braking of the two head end locomotives, it only retarded the wheels of those two locomotives.  All of the 210 cars trailing the locomotives had no braking at all acting on their wheels.  If you use air brakes, then all 840 car wheels of the train will have brake shoes pressing into them. 

 

Granted, the locomotives are heavier than the cars, so dynamic brakes do cause the locomotives to have considerable retarding force.  But the 210 cars, having no retarding force of their own, will run in hard against the dynamic braked locomotives.  And especially if there is a concentration of weight at the rear of the train those heavier cars will run in very hard against the lighter cars in the middle of the train with a high probability of buckling the train due to the concentrating of buff (compression) force.  According to the FRA, that is exactly what happened.   

 

Another point that played a part in this wreck was the fact resistive braking force generated by the dynamic braking of the head end locomotives will not affect all 210 cars until the slack runs in and bunches every one of the 420 coupling joints of the train.  And while that slack is running in, if any of the track is downhill for the train, any cars in that downhill area that have not yet run in, will be accelerating due to the pull of gravity.  So when the final run-in occurs, it may be that the colliding cars  are running 10-20 mph faster  than the cars that have already run in and formed a tight block.  Then running straight into that blockage with an impact speed of 10-20 mph, comes a large line of empty, cars followed by a slug of heavy loads at the tail end.    

[tree68]

Euclid

If you use air brakes, then all 840 car wheels of the train will have brake shoes pressing into them. 

And all 840 brake shoes are just that much closer to replacement.  Brake shoes cost money, as does the labor to replace them.  It may not sound like much, but with hundreds of thousands of cars in circulation, it adds up.

Smart automobile drivers use "dynamic braking" all the time. Better known as engine braking.  Either that, or let geography help - going up a hill?  Just let gravity slow  you down.  Why wear out one's brakes?

[BaltACD]

tree68

 

Overmod 

charlie hebdo

You missed the key point of Bucky's post, namely that the doomed train lacked sufficient braking capability. 

But wasn't a key point at Springfield that there was too much (or more precisely too quickly, or poorly modulated) head-end-only dynamic braking, causing run-in acceleration in part of the lightly-loaded intermediate section of the consist?  

One could argue that there was too much braking capacity, in the wrong place...

An thus we have the most critical element of a Engineers performance in getting his train SAFELY across the road.

Gross manipulation of throttle and braking systems can tear trains apart and derail them. 

Engineers are ones who MASTER the finess of manipulating the tools of their trades.  How do Engineers master their tools, train after train after train, trip after trip after trip - every train and trip is a learning experience, several synapse of gray matter are filed about the minuate of today's train operation as compared to hundreds if not thousands of trips with other trains and the sensations those train transmitted to the Engineer when various train handling techniques were applied at various locations on each trip.

Engineers are planning their control inputs miles in advance of when those inputs are going to be necessary, as in many cases certain actions have to be completed prior to those inputs.  As operators of automobiles, we are able to safely respond to virtually any situation we can see before the situation becomes an accident.  Railroad Engineers on Main tracks cannot operate at track speeds within their range of vision; they have to be planning actions for situations they know will present themselves but they cannot see them yet.

[BigJim]

Euclid

So when this train applied dynamic braking of the two head end locomotives, it only retarded the wheels of those two locomotives.  All of the 210 cars trailing the locomotives had no braking at all acting on their wheels.  If you use air brakes, then all 840 car wheels of the train will have brake shoes pressing into them. 

Once again, you have no idea how to run a train nor the proper use of the automatic brake! 

[Euclid]

BigJim

 

 

Euclid

So when this train applied dynamic braking of the two head end locomotives, it only retarded the wheels of those two locomotives.  All of the 210 cars trailing the locomotives had no braking at all acting on their wheels.  If you use air brakes, then all 840 car wheels of the train will have brake shoes pressing into them. 

 

 

Once again, you have no idea how to run a train nor the proper use of the automatic brake! 

 

I have never claimed to have any idea of how the train should have been handled.  I did say, “If you use air brakes, then all 840 car wheels of the train will have brake shoes pressing into them.”  Is that not a true statement?  It is only to distinguish the effects of air brakes compared to dynamic brakes.  It has nothing to do with what the engineer of this train should have done, as you seem to be interpreting from my statement about the difference between air brakes and dynamic brakes.

 

But in any case, why don’t you tell us what you would have done to reduce speed as was done with that NS train when it slowed down at Springfield, OH and buckled in about the middle. 

 

This what the FRA has concluded so far:

 

“FRA's investigation into this incident is currently ongoing, but preliminary indications show excessive buff force due to train makeup and train handling are the primary causes of the incident.”

 

If the FRA is right about part of the cause being the train handling, what might they be referring to? 

[zugmann]

Was the engineer running the train - or was the software?

[Euclid]

zugmann

Was the engineer running the train - or was the software?

 

I don’t know.  The FRA cites this wreck as an example of excess in-train forces that they warn about.  In the part I quoted in blue above, they refer to “train makeup and train handling” as being the cause, but they don’t say that the train handling was being done by computer.  If it was being done by computer, it would seem that the FRA is in remiss for not mentioning that critical fact.    

 

The FRA does say that the 210-car train was operating as a conventional train with all the power on the head end.  They said the train was decelerating by the use of dynamic braking from the 2 lead units when buff force peaked at bottom of a sag as approximately the last 105 cars ran-in while descending that sag.  Coincidentally, this point of derailment was captured on video by a driver waiting at a grade crossing. 

[tree68]

One might conclude that while longer trains may be a factor in derailments, train make-up and handling may be the bigger piece.

Would the Springfield derailment have happened if everything behind the middle of the train was empties?  Rhetorical question, but a consideration.

[Euclid]

tree68

One might conclude that while longer trains may be a factor in derailments, train make-up and handling may be the bigger piece.

Would the Springfield derailment have happened if everything behind the middle of the train was empties?  Rhetorical question, but a consideration.

 

I think that it is train makeup and handling that are the typical final triggers in derailing ultra-long trains.  That seems to be the position of the FRA as well.  But the FRA position also seems to be that it is the extreme train length that is the underlying cause.  Clearly they say that ultra-long trains are more difficult for engineers to control and operate without derailing, compared to the conventional size trains.

 

They also say that is not acceptable to simply allow engineers who are experienced only with conventional trains to learn to operate the ultra-long trains just by gaining on the job experience with them.  The FRA says the differences between the conventional trains and ultra-long trains is so great that engineers must receive new classroom instruction and training before being allowed to operate them on the job. 

 

To your rhetorical question:  I think it is quite possible or likely that the derailment would not have happened if the trailing half of the consist was all empties.  Also the derailment was far less likely had the trailing half not been descending the sag at the same time the leading half was ascending the sag.  And also I think there is a good chance that the derailment would not have happened if dynamic braking were being applied from both the head end and from the mid-train DPU, rather just all from the head end.

[SFbrkmn]

Many of these mega trains are not just bulk unit or intermodal movements, but mixed freight that is asking for a nightmare to happen. 25 yrs on the rails and these trains make me nervous. Crew has to carefully look over the profile tonnage to aboslutely make sure the train is in tonnage compliance. Some trains are barely in compliance. Either way, it is nothng but a five digit footage slingshot banging you around in the seat hoping you have armrests to prevent being tossed onto the floor making for a miserable trip w/the hope auto control does not create a break-in two of a knuckle, drawbar or derailment. Regardless of it is a auto or manual control, any breakdown generates the self asked thought "Should have laid off for this trip".

Sam 

[Psychot]

For those of us who have zero experience in the railroad industry, it's invaluable to have railroaders in this forum sharing their experiences. Having said that, some of you might want to consider being a bit less condescending in your replies. Educate us, rather than simply typing the equivalent of "you don't know $hit."

[BaltACD]

Psychot

For those of us who have zero experience in the railroad industry, it's invaluable to have railroaders in this forum sharing their experiences. Having said that, some of you might want to consider being a bit less condescending in your replies. Educate us, rather than simply typing the equivalent of "you don't know $hit."

There comes a point in time, after repeated attempts to educate a particular participant without success, one has to come to the realization that the participant 'don't know s..t' and doesn't want to know.

[Euclid]

SFbrkmn

Many of these mega trains are not just bulk unit or intermodal movements, but mixed freight that is asking for a nightmare to happen. 25 yrs on the rails and these trains make me nervous. Crew has to carefully look over the profile tonnage to aboslutely make sure the train is in tonnage compliance. Some trains are barely in compliance. Either way, it is nothng but a five digit footage slingshot banging you around in the seat hoping you have armrests to prevent being tossed onto the floor making for a miserable trip w/the hope auto control does not create a break-in two of a knuckle, drawbar or derailment. Regardless of it is a auto or manual control, any breakdown generates the self asked thought "Should have laid off for this trip".

Sam 

 

 

Sam,

 

Your point is well made when you refer to monster trains as being, “nothing but a five digit footage slingshot banging you around in the seat hoping you have armrests to prevent being tossed onto the floor…”

 

The long slack action can allow a portion of the train to roll faster than the rest of it even though all the cars are coupled together.  So, in effect, in one long train, you can have two different, independent trains; and a collision between them.

 

The longer the whole train is, the larger those two independent trains are, and the more violent the collision can be.  So it follows that the potential for relatively longer trains to have a greater chance of derailing due to in-train forces is a fact.    

[charlie hebdo]

I think Sam's comments of first-hand experience with handling very long trains is definitive.  Longer trains (actually they are often several trains coupled together to reduce labor costs) are more prone to derailments.

[Overmod]

BaltACD

Psychot

For those of us who have zero experience in the railroad industry, it's invaluable to have railroaders in this forum sharing their experiences. Having said that, some of you might want to consider being a bit less condescending in your replies. Educate us, rather than simply typing the equivalent of "you don't know $hit."

There comes a point in time, after repeated attempts to educate a particular participant without success, one has to come to the realization that the participant 'don't know s..t' and doesn't want to know.

But the specific thing he's talking about is the comment from Big Jim, that was dismissive to him without explaining why.  All he's asking for is that the reply include why what he posted was 'wrong' -- even if that's just a couple of lines, an URL for the current Al Krug site, or whatever.

[BaltACD]

Don't forget the 'What about?'

[Cotton Belt MP104]

Not being an locomotive engineer, I can not speak from experience.

But I have read enought and logic would make sense that due to the many variable forces in a rolling train, operating by the "seat of your pants" (as the expression goes) is far superior to automation, while nice, automation has limits to variables that are not programed in, only the basics which might be several. BUT....Ain't nutin' compared to years of experience.

As an example: Airlines (look it up: Children of Magenta) have had pilots depend on auto pilot so much that they don't take off the auto pilot (when seat of the pants assesment of their situational awarness indicates, WE ARE IN TROUBLE.). They continue to depend on the automation with disasterous results. Some pilots have warned/commented, "For heaven sakes, you learned to fly a plane without auto pilot, TURN that darn computer off and fly it like you know a plane should be flown" endmrw0621231354 

[Cotton Belt MP104]

As I went through this thread there were remarks that seemed to indicate some unkind remarks had been made. I was subject to that at one time and refused to post anything.

As I have said before if a participant is seemingly pretending to be an expert and is not, the method of dealing with the bulk of those comments can be ignored (I mentioned "extinction"). While it is true that the "dull and ignorant, they too have their story and should be heard to an extent. This is only civil behavior. But when the story and details are of extraordinary length one seems to not gain that much, even a flaw in information can be present (intentional or not) and that draws a reaction from those who know better....and the verbal fight is on.

Example: Posted by Euclid on Thursday, June 1, 2023 10:02 AM : In the comment there is a statement:   ““If you use air brakes, then all 840 car wheels of the train will have brake shoes pressing into them.”  Is that a not true statement?”  

 

Even with the FRED which sends the “signal to brake” from rear as front is sending backward the signal to brake. This is a cascading operation and not immediate “all 840 wheels…have brake shoes pressing” ?  He Did Ask The Question is that not a true statement?  And I was wondering if I was right that the statement is not right.  Endmrw0621231426

[BaltACD]

Cotton Belt MP104

Not being an locomotive engineer, I can not speak from experience.

But I have read enought and logic would make sense that due to the many variable forces in a rolling train, operating by the "seat of your pants" (as the expression goes) is far superior to automation, while nice, automation has limits to variables that are not programed in, only the basics which might be several. BUT....Ain't nutin' compared to years of experience.

As an example: Airlines (look it up: Children of Magenta) have had pilots depend on auto pilot so much that they don't take off the auto pilot (when seat of the pants assesment of their situational awarness indicates, WE ARE IN TROUBLE.). They continue to depend on the automation with disasterous results. Some pilots have warned/commented, "For heaven sakes, you learned to fly a plane without auto pilot, TURN that darn computer off and fly it like you know a plane should be flown" endmrw0621231354 

For any that are interested - the Mentour Pilot YouTube channel has a series of accident investigation videos - Very enlightening.

https://www.youtube.com/watch?v=ylLjnLh_XA4&t=27s

 

 

Note - the plane crashed on the Trans-Siberian Railroad.

[Backshop]

Cotton Belt MP104

 

As an example: Airlines (look it up: Children of Magenta) have had pilots depend on auto pilot so much that they don't take off the auto pilot (when seat of the pants assesment of their situational awarness indicates, WE ARE IN TROUBLE.). They continue to depend on the automation with disasterous results. Some pilots have warned/commented, "For heaven sakes, you learned to fly a plane without auto pilot, TURN that darn computer off and fly it like you know a plane should be flown" endmrw0621231354 

 

The same thing happened with the Asiana flight into San Francisco.  My brother is a retired Delta A320 captain and was often frustrated by some of the younger pilots. They didn't want to "fly" the airplane.  My brother started as an army chopper pilot and enjoyed handflying planes.

[Cotton Belt MP104]

Reference Asiana/flight/SF

Sad but true. The plane "crashed" but foam was on the runway to prevent fire. No one was injured, EXCEPT one young lady perished as she was in the foam and run over by a firetruck. endmrw0622232119

[rdamon]

Backshop

 

 

The same thing happened with the Asiana flight into San Francisco.  My brother is a retired Delta A320 captain and was often frustrated by some of the younger pilots. They didn't want to "fly" the airplane.  My brother started as an army chopper pilot and enjoyed handflying planes.

 

 

Talking to Airbus drivers they have the equivilent of Trip Optimizer. Climb, Cruise and Decent is all managed by the FMS (Flight Management System) computer. Do it yourself and get out line, expect a call from your union rep as the system will phone home. 

[zugmann]

Cotton Belt MP104

Sad but true. The plane "crashed" but foam was on the runway to prevent fire. No one was injured, EXCEPT one young lady perished as she was in the foam and run over by a firetruck. endmrw0622232119

Asiana Flight 214?  3 killed, 180-some injured. You may be thinking of another incident? 

And they knew the one girl was laying in the grass before they sprayed foam (video proof - easily avaliable).  Then they sprayed foam and ran her over - made all the worse because the truck didn't have its thermo cameras installed yet, depsite the FAA regulation on same. 

[zugmann]

rdamon

Talking to Airbus drivers they have the equivilent of Trip Optimizer. Climb, Cruise and Decent is all managed by the FMS (Flight Management System) computer. Do it yourself and get out line, expect a call from your union rep as the system will phone home. 

But when those systems crap out, or something huge and out of the ordinary pops up, then the company expects the pilots (or engineers) to have the skills of a 30-yr man that has been running every day.  

Can't. Have. It. Both. Ways.  

[Euclid]

Cotton Belt MP104

As I went through this thread there were remarks that seemed to indicate some unkind remarks had been made. I was subject to that at one time and refused to post anything.

As I have said before if a participant is seemingly pretending to be an expert and is not, the method of dealing with the bulk of those comments can be ignored (I mentioned "extinction"). While it is true that the "dull and ignorant, they too have their story and should be heard to an extent. This is only civil behavior. But when the story and details are of extraordinary length one seems to not gain that much, even a flaw in information can be present (intentional or not) and that draws a reaction from those who know better....and the verbal fight is on.

Example: Posted by Euclid on Thursday, June 1, 2023 10:02 AM : In the comment there is a statement:   ““If you use air brakes, then all 840 car wheels of the train will have brake shoes pressing into them.”  Is that a not true statement?”  

 

Even with the FRED which sends the “signal to brake” from rear as front is sending backward the signal to brake. This is a cascading operation and not immediate “all 840 wheels…have brake shoes pressing” ?  He Did Ask The Question is that not a true statement?  And I was wondering if I was right that the statement is not right.  Endmrw0621231426

 

The topic of the thread title simply asks whether the recent trend of large increases of train length made possible by distributed power are having the unintended consequence of causing an increase in derailments.  This possibility is based on the fact that the greater train length increases the amount of train slack action, and that leads to greater in-train forces related to slack running in and out. 

 

The FRA believes that the answer to the question is:  “Yes the longer trains have a higher probability of derailing.”  They have released a report on this matter.  In the report, they also cite three recent derailments which they review in detail, and conclude that they were caused by excess in-train forces.

 

One of them is the Norfolk Southern derailment that occurred at Springfield, OH, a couple weeks after the East Palestine derailment.  I have posted the FRA analysis of this wreck several times in this thread, but so far nobody has indicated that they have read it.

 

Essentially, the FRA says that the 210-car train had two engines on-line on the head end, which were being used for dynamic braking.  There was also a DPU engine mid-train, but it was not being used for dynamic braking.  The FRA report leaves the impression that this head end dynamic braking by two engines is the only braking being used at the time. 

 

FRA also says that the train weight was relatively higher toward the front and rear of the train; and was lower near the middle of the train. 

 

At the time of the derailment, the train was moving around 45 mph, and was approximately centered on a sag in the track profile.  So the front 105 cars of the train was running uphill, and the rear 105 cars were running downhill while being retarded by dynamic braking.  The engineer was increasing the dynamic brakes to slow the train while passing through the town.  Incidentally, I would like to know whether the FRA is saying that this dynamic braking was the only braking in effect at the time.  They imply that was the case.  If so, you have a 210-car train being slowed only by increasing the turning resistance of the wheels of two locomotives on the head end of the train.

 

At the moment of derailment, the front half of the train was running uphill with slack compression building rearward thought its cars as dynamic braking propagated back from the head end.  Also adding retardation to the front half of the train was the fact that it was running uphill and thus being slowed by gravity in addition to dynamic braking.

 

Meanwhile, the bunching slack in the uphill running head end had not yet reached the second half of the train which was freely rolling downhill and accelerating under the force of gravity without any braking, and with slack generally loose.  So, within  the range of slack, the uphill head end was decelerating and the downhill hind end was accelerating.  This is leading to a form of head-on collision that would be very interesting to study with computer modeling.   

 

As the moment of derailment approached, the head-end slack had begun to continue its running into the second half of the train.    

 

At that moment, two empty coil steel cars entered a grade crossing at the bottom of the sag.   At that same moment, the buff force of compression advancing from front to rear, reached its highest pressure, and caused the train to buckle and derail between the two steel coil cars.

 

+++++++++++++++++++++++++++++++

 

 

My point about the number of brake shoes touching the car wheels was only to illustrate that with dynamic brakes being used, there are no brake shoes touching the wheels.  I even included that clarification along with stating the point as posted further up on this page.   I made this point specifically in reference to the Springfield, OH wreck that I reviewed above.  Using only dynamic brakes from only two head-end locomotives, as the sole braking for a 210-car train with sub-optimal train make-up; in territory with “hogback” or undulating track profile--- This combination strikes me as being extremely risky.   

 

To the question of whether human operator skill is better than computer autonomous operation, that point has not much come up with this topic of longer trains causing more derailments due to excess in-train forces.  However, a piece of the in-train force puzzle is train make-up, and computer programs have been developed to make the decisions for optimal placement into the train consist, of various types and weights of railcars.  Like all programs, all they need is more work. 

 

But for autonomous operation there is no train crew.  Without a train crew, there is no reason to run monster trains in order to move more cars with one crew.  If anything, autonomous running implies shorter trains of say 50-75 cars maximum to take advantage of all the virtues of short trains with their more nimble operation.  Maybe then we could have an operation actually looks like “Precision Scheduled Railroading.”

[BaltACD]

Euclid

... 

But for autonomous operation there is no train crew.  Without a train crew, there is no reason to run monster trains in order to move more cars with one crew.  If anything, autonomous running implies shorter trains of say 50-75 cars maximum to take advantage of all the virtues of short trains with their more nimble operation.  Maybe then we could have an operation actually looks like “Precision Scheduled Railroading.”

Wrong again!  Track capacity is track capacity no matter if the trains are crewed or not.  It is exceedingly easy to unleash too many trains on a particular track segement to permit fluid operations.  

How do these autonomous trains perform the 'block swappng' that is one of the hallmarks of the PSR operating plan - setting off and picking up on line of road?  Even in pre PSR operating plans trains pick up and set off at points along their runs.

[Cotton Belt MP104]

 

 Zug.   Good info. My reference to specific flight (my bad) was only using what was mentioned earlier. Sine you have the video of the girl being run over, you probably have the correct flight info. I will be looking up BOTH incidents. Famous hero Schullenberger (sp?) sure did his best when things didn't go right. To keep this on RR topic...same can be said of RR engineers who operate by the "seat of his pants" in otherwords (gauges important also) what he feels that can't be measured makes a HUGE difference in his moves.

interesting detail about infared detector and rules not obeyed endmrw0623231449

your comments below

Asiana Flight 214?  3 killed, 180-some injured. You may be thinking of another incident? 

And they knew the one girl was laying in the grass before they sprayed foam (video proof - easily avaliable).  Then they sprayed foam and ran her over - made all the worse because the truck didn't have its thermo cameras installed yet, depsite the FAA regulation on same. 

 

[/quote]