charlie hebdoMany advantages there. If off-peak=night, then with quick cleanups they can pretend it never happened.
The only thing is at night they might have to pay employees overtime or shift differential, thus costing more. Public relations often seems rather low on the priority. The possibility of saving a couple of thousand dollars by scheduling the derailment at the start of the normal working hours will be attractive!
Murphy Siding Overmod Murphy Siding Due to an unscheduled derailment no doubt. You mean to imply scheduled derailments and precision scheduled derailroading have become a 'thing' now? Hmmmm... Euclid and I have to ponder this. Wouldn't the next logical step in PSR be to schedule the derailments in the off-peak hours? I mean, it looks good on paper, so it's gotta work.
Overmod Murphy Siding Due to an unscheduled derailment no doubt. You mean to imply scheduled derailments and precision scheduled derailroading have become a 'thing' now? Hmmmm... Euclid and I have to ponder this.
Murphy Siding Due to an unscheduled derailment no doubt.
You mean to imply scheduled derailments and precision scheduled derailroading have become a 'thing' now? Hmmmm... Euclid and I have to ponder this.
Wouldn't the next logical step in PSR be to schedule the derailments in the off-peak hours? I mean, it looks good on paper, so it's gotta work.
Many advantages there. If off-peak=night, then with quick cleanups they can pretend it never happened.
Thanks to Chris / CopCarSS for my avatar.
oltmanndThey guys who are pretty astute about budgets, rules and safety aren't always the best at physics..
Scheduled derailmets? I will have to think about that one also. Must be part of EHH's PSR philosp[hy.
Murphy SidingDue to an unscheduled derailment no doubt.
BaltACD rdamon BaltACD The available pictures don't show that this was a 'stringline' type derailment. Agree, This is just a recent event that I did not think warrented a new thread. I agree however, Amtrak's excuse of 'unscheduled trackwork' is unique.
rdamon BaltACD The available pictures don't show that this was a 'stringline' type derailment. Agree, This is just a recent event that I did not think warrented a new thread.
BaltACD The available pictures don't show that this was a 'stringline' type derailment.
The available pictures don't show that this was a 'stringline' type derailment.
I agree however, Amtrak's excuse of 'unscheduled trackwork' is unique.
Never too old to have a happy childhood!
BaltACD Neither accordian or jacknife are causes of derailments - they are results of a derailment and are caused by the need to disapate the remining kenitic energy that is contined in the still moving portion of the train after the originally derailed car begins moving slower than all the cars that are following it. If train A-Z has 26 cars. Car A derails on comes to a stop in very short order - the kinetic energy in cars B-Z has to be disapated - with car A derailed it will not remain in perfect alignment with cars B-Z - the angular difference between A & B will define how the accordian will affect the movement of cars B-Z as the disapate their retained kenitic energy from the moment of derailment. We have all seen this before, but it indicates kinetic energy needing to be dispated in a derailment better than most
Neither accordian or jacknife are causes of derailments - they are results of a derailment and are caused by the need to disapate the remining kenitic energy that is contined in the still moving portion of the train after the originally derailed car begins moving slower than all the cars that are following it.
If train A-Z has 26 cars. Car A derails on comes to a stop in very short order - the kinetic energy in cars B-Z has to be disapated - with car A derailed it will not remain in perfect alignment with cars B-Z - the angular difference between A & B will define how the accordian will affect the movement of cars B-Z as the disapate their retained kenitic energy from the moment of derailment.
We have all seen this before, but it indicates kinetic energy needing to be dispated in a derailment better than most
Yes, I understand those points very well. Actually, though, I would say that stringlining is also the result of a derailment and not the cause, just as jacknifing is the result not the cause. The cause of stringlining is too much transverse force produced by pulling cars too hard through a curve. When the limit to this force is reached, a wheel climbs the rail, and only that excessive transverse force is the cause of the derailment. Everything from that first wheel climbing the rail to the point where the action stops is the result of the derailment. So a stringling is the result of too much transverse force by pulling too hard through a curve. Only the excess transverse force is the cause.
We have all seen this before, but it indicates kinetic energy needing to be dispated in a derailment better than most -
Yeah I knew you were going to say that. But is that accordion result not a type?
Is an accordion the same as a jacknife? It seems to me that a jacknife is the opposite of a stringline.
Euclid BaltACD The available pictures don't show that this was a 'stringline' type derailment. That is an accordion type derailment.
That is an accordion type derailment.
Accordian is not a type of derailment - it is a result of a derailment.
New vehicles -- so the UP train must have been westward? Which means downgrade.
rdamonThirty-three train cars derailed yesterday morning roughly 30 miles from the Nevada-Utah border near the small town of Caliente https://www.msn.com/en-us/autos/news/brand-new-jeep-gladiators-and-chevy-silverados-destroyed-after-train-derails-in-nevada/ar-AAEbqlI?ocid=spartanntp
https://www.msn.com/en-us/autos/news/brand-new-jeep-gladiators-and-chevy-silverados-destroyed-after-train-derails-in-nevada/ar-AAEbqlI?ocid=spartanntp
Thirty-three train cars derailed yesterday morning roughly 30 miles from the Nevada-Utah border near the small town of Caliente
So, short story about testing SD60MACs on Conrail.
Our department was coordinating the test - me in particular. So, they wanted to run an ore train of solid ore jennies west over HSC. "We want to put all three SD60MACs on line and see if we can't pull the hill without helpers." said the division. "No. It won't work. You'll get a knuckle. You need to push the train." we said. "We just want to try it." Said the division. "Don't." we said.
They tried it. Didn't even get to the brickyard. Bang! Pulled the entire draftgear out of one of those old 100 ton ore jennies.
"We told you so." we thought to ourselves.
They guys who are pretty astute about budgets, rules and safety aren't always the best at physics....
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
Euclid zugmann Euclid I am referring to a program that would prevent stringlining by knowing the train makeup and tonnage distrubution, and knowing the train's location on the railroad line, while monitoring tractive effort. By knowing the train makeup and tonnage distribution, it would know where the stringline threshold is at every point on the line. It would have a built-in safety margin, and would reduce tractive effort if the stringline threshold was getting too close. With this magic system, you would not have the problem of a difference of opinion as to whether or not a train would stringline. They've had that stuff since LEADER. Then why are they stringlining trains?
zugmann Euclid I am referring to a program that would prevent stringlining by knowing the train makeup and tonnage distrubution, and knowing the train's location on the railroad line, while monitoring tractive effort. By knowing the train makeup and tonnage distribution, it would know where the stringline threshold is at every point on the line. It would have a built-in safety margin, and would reduce tractive effort if the stringline threshold was getting too close. With this magic system, you would not have the problem of a difference of opinion as to whether or not a train would stringline. They've had that stuff since LEADER.
Euclid I am referring to a program that would prevent stringlining by knowing the train makeup and tonnage distrubution, and knowing the train's location on the railroad line, while monitoring tractive effort. By knowing the train makeup and tonnage distribution, it would know where the stringline threshold is at every point on the line. It would have a built-in safety margin, and would reduce tractive effort if the stringline threshold was getting too close. With this magic system, you would not have the problem of a difference of opinion as to whether or not a train would stringline.
They've had that stuff since LEADER.
Then why are they stringlining trains?
see title of post!
Sometimes reality intrudes into fairyland.
EuclidThen why are they stringlining trains?
I don't know. Why are they?
It's been fun. But it isn't much fun anymore. Signing off for now.
The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.t fun any
EuclidI am referring to a program that would prevent stringlining by knowing the train makeup and tonnage distrubution, and knowing the train's location on the railroad line, while monitoring tractive effort. By knowing the train makeup and tonnage distribution, it would know where the stringline threshold is at every point on the line. It would have a built-in safety margin, and would reduce tractive effort if the stringline threshold was getting too close. With this magic system, you would not have the problem of a difference of opinion as to whether or not a train would stringline.
Euclid BaltACD JPS1 oltmannd Which even my "back of the envelope" calculation showed is what likely happened. Getting to L/V is tougher to do and you can't reasonably determine it for every car in every location under every possible circumstance. There are trains built and run that will just plain derail if the go into emergency at the right spot. But, they don't, so no news is good news... How long did it take from the beginning of the railroad era for engineers to work out the mathematics to explain all the forces impacting operations? Or is it still a work in progress? Still a work in progress as they try to maximize tonnage and minimize costs. I would think they would have a program that would predict the stringline potential of any given train, based on makeup, gradient, power, and curvature. Maybe it could also take over and prevent the stringline event from happening.
BaltACD JPS1 oltmannd Which even my "back of the envelope" calculation showed is what likely happened. Getting to L/V is tougher to do and you can't reasonably determine it for every car in every location under every possible circumstance. There are trains built and run that will just plain derail if the go into emergency at the right spot. But, they don't, so no news is good news... How long did it take from the beginning of the railroad era for engineers to work out the mathematics to explain all the forces impacting operations? Or is it still a work in progress? Still a work in progress as they try to maximize tonnage and minimize costs.
JPS1 oltmannd Which even my "back of the envelope" calculation showed is what likely happened. Getting to L/V is tougher to do and you can't reasonably determine it for every car in every location under every possible circumstance. There are trains built and run that will just plain derail if the go into emergency at the right spot. But, they don't, so no news is good news... How long did it take from the beginning of the railroad era for engineers to work out the mathematics to explain all the forces impacting operations? Or is it still a work in progress?
oltmannd Which even my "back of the envelope" calculation showed is what likely happened. Getting to L/V is tougher to do and you can't reasonably determine it for every car in every location under every possible circumstance. There are trains built and run that will just plain derail if the go into emergency at the right spot. But, they don't, so no news is good news...
Getting to L/V is tougher to do and you can't reasonably determine it for every car in every location under every possible circumstance. There are trains built and run that will just plain derail if the go into emergency at the right spot. But, they don't, so no news is good news...
How long did it take from the beginning of the railroad era for engineers to work out the mathematics to explain all the forces impacting operations? Or is it still a work in progress?
Still a work in progress as they try to maximize tonnage and minimize costs.
I would think they would have a program that would predict the stringline potential of any given train, based on makeup, gradient, power, and curvature. Maybe it could also take over and prevent the stringline event from happening.
I am referring to a program that would prevent stringlining by knowing the train makeup and tonnage distrubution, and knowing the train's location on the railroad line, while monitoring tractive effort. By knowing the train makeup and tonnage distribution, it would know where the stringline threshold is at every point on the line. It would have a built-in safety margin, and would reduce tractive effort if the stringline threshold was getting too close.
With this magic system, you would not have the problem of a difference of opinion as to whether or not a train would stringline.
The derailment several months ago on the CSX's Baltimore Belt Line that overturned cars into and damaging parts of the Baltimore Streetcar Museum was a stingline event caused with the DPU lost communications with the head end locomotives and shut down thus creating excessive trailing tonnage for the curvature the head end was operating through.
Excessive trailing tonnage can happen, even when you aren't expecting it.
JPS1 oltmannd Which even my "back of the envelope" calculation showed is what likely happened. Getting to L/V is tougher to do and you can't reasonably determine it for every car in every location under every possible circumstance. There are trains built and run that will just plain derail if the go into emergency at the right spot. But, they don't, so no news is good news... How long did it take from the beginning of the railroad era for engineers to work out the mathematics to explain all the forces impacting trains operations? Or is it still a work in progress?
How long did it take from the beginning of the railroad era for engineers to work out the mathematics to explain all the forces impacting trains operations? Or is it still a work in progress?
There are, and have been for quite a while, simulations that will calculate L/V for a train dynamically. They have typically been used to help find derailment causes and figure out what general rules, if any, could be used to reasonably avoid the situation in the future.
caldreamer Writing such a program is not that difficult. If the train is approching the stringline point information could be bass to the PTC system which could then slow the train down. Caldreamer
Writing such a program is not that difficult. If the train is approching the stringline point information could be bass to the PTC system which could then slow the train down.
Caldreamer
It's not the speed, really. It's the force the locomotives are generating. The train just "pulls back" with train resistence plus acceleration.
caldreamerWriting such a program is not that difficult. If the train is approching the stringline point information could be bass to the PTC system which could then slow the train down.
Stringlining can come from approaching a curve too slow, necessitating you to go deeper into the throttle quicker to keep from stalling. More about yanking it too hard, than going too fast.
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