BaltACD BigJim Euclid What is your estimate for the stopping distance for #91 with an emergency application, at the location of the collision, assuming it was an engine and eight cars, and traveling at 56 mph? I did not have enough time running AMTRAK equipment to even venture a guess. A whole lot more than the estimated 250 foot sight line, in any event.
BigJim Euclid What is your estimate for the stopping distance for #91 with an emergency application, at the location of the collision, assuming it was an engine and eight cars, and traveling at 56 mph? I did not have enough time running AMTRAK equipment to even venture a guess.
Euclid What is your estimate for the stopping distance for #91 with an emergency application, at the location of the collision, assuming it was an engine and eight cars, and traveling at 56 mph?
I did not have enough time running AMTRAK equipment to even venture a guess.
A whole lot more than the estimated 250 foot sight line, in any event.
Euclid That number is my estimate for distance to switch points when their position became visible
How did you arrive at this estimate?
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
BigJimBut not as much as the news media would have you think. It is remarkable how quickly they can stop!
I don't know if the following chart gives an usefull estimate.www.caltrain.com/assets/_engineering/engineering-standards-2/Drawings/5000s/SD-5006.pdf
The chart gives braking distances for Caltrans trains for signalling purposes. So the results are not the shortest max. service brake applications but contain a safety margin. The given braking distance for 56 mph is 3270 ft.
Now we miss a ratio of max. service application and emergency braking distances.Regards.
zugmann Euclid That number is my estimate for distance to switch points when their position became visible How did you arrive at this estimate?
Just based on recollections of watching switch points. What is your estimate?
EuclidJust based on recollections of watching switch points. What is your estimate?
When did you watch switch points? And from where?
Some one please clarify. It was stated that 91 waited about 10 - 20 minutes at the north end of the signal suspension for a track warrant. Is that correct ?
If so was that because the dispatcher was waiting for the release of the track warrant by the CSX crew ?
How long did it take 91 when released to reach the collision point ?
What did the CSX crew do after they released their warrant ?
The CSX loco recorders if survived may have some indications of what occurred by the CSX crew ?
Observed a signal bungalow at the end of the curve from the north. Any idea what its function could be ? Any possibility that it has been put there to verify switch positions of the switches just to the south ?i
Volker, have you looked in the table provided in the TSB report that NDG cited in String Lining. There are data there that might be used to derive a starting place for 'corrections' based on 91's braking ratios, speed profile, etc.
zugmann Euclid Just based on recollections of watching switch points. What is your estimate? When did you watch switch points? And from where?
Euclid Just based on recollections of watching switch points. What is your estimate?
Apparently being an academic makes you an expert inquirer on any potential subject so long as you can ask a billion questions of and seek a billion possible solutions to problems that have no actual solution.
Or, you could just listen to the actual authorities on these issues. We have legions of train operating folks on here and yet some ignore their experience and wisdom.
Maybe, just maybe, we've found a case where academics will never know more than the people who do that job on a daily basis.
But that won't ever stop them. It's tiring to read and detracts from the real discussion and insight that comes from listening to the people who actually DO THIS JOB. They're the authority on this issue, and way more worthwhile to listen to than those who seem hell-bent on ensuring the thread goes on forever with their propositions and academic reasoning.
I'm no railroad operating man but I know enough and have heard enough listening to them that I bet a certain somebody here would probably be crapping their pants if they ever had to run a real freight or passenger train - when propositions are worthless and mistakes can kill.
OvermodVolker, have you looked in the table provided in the TSB report that NDG cited in String Lining.
No I haven't. I didn't follow that thread.Regards; Volker
Saturnalia zugmann Euclid Just based on recollections of watching switch points. What is your estimate? When did you watch switch points? And from where? Apparently being an academic makes you an expert inquirer on any potential subject so long as you can ask a billion questions of and seek a billion possible solutions to problems that have no actual solution. Or, you could just listen to the actual authorities on these issues. We have legions of train operating folks on here and yet some ignore their experience and wisdom. Maybe, just maybe, we've found a case where academics will never know more than the people who do that job on a daily basis. But that won't ever stop them. It's tiring to read and detracts from the real discussion and insight that comes from listening to the people who actually DO THIS JOB. They're the authority on this issue, and way more worthwhile to listen to than those who seem hell-bent on ensuring the thread goes on forever with their propositions and academic reasoning. I'm no railroad operating man but I know enough and have heard enough listening to them that I bet a certain somebody here would probably be crapping their pants if they ever had to run a real freight or passenger train - when propositions are worthless and mistakes can kill.
I hope you mean academic as in theoretical or hypothetical and not as relating to higher education or being scholarly.
Thanks to Chris / CopCarSS for my avatar.
Streak, we're likely going to have to wait for the next preliminary NTSB report to know any of that in a reasonable way. About the only thing that is indisputably clear is the EO 24 violation, because overt events confirm it. That is far from 'explaining' what happened, though -- and we need the detailed results of the interviews, or an intelligent synopsis of them, before we can do anything more than rank supposition.
I don't think zugmann is an acedemic.
EuclidI don't think zugmann is an acedemic.
Gonnna insult my mother too, while you're at it? Go right ahead - she's dead and won't mind.
I don't know what your definition of "academic" is, but I do have a college degree.
zugmannI don't know what your definition of "academic" is, but I do have a college degree.
In?
Electroliner 1935In?
a drawer.
zugmann It's in a drawer. Q Clever will get you many places. What discipline and from what College, please. I wish I could learn more about Bucky but he does not want to tells anything about himself
It's in a drawer.
Q
Clever will get you many places. What discipline and from what College, please. I wish I could learn more about Bucky but he does not want to tells anything about himself
zugmannIt's in a drawer.
Nah, not important. Nothing that would impress you. Hell it doesn't even impress me. I don't really consider myself an academic, tbh.
zugmann Nah, not important. Nothing that would impress you. Hell it doesn't even impress me. I don't really consider myself an academic, tbh. Ahh, another EUCLID. I thought better of you.
Ahh, another EUCLID. I thought better of you.
Electroliner 1935Ahh, another EUCLID. I thought better of you.
Think what you want. I don't care.
Ahh - but there is a difference - Zug has bona fide railroad experience.
I've got two associates degrees - they're in a drawer, too (or are they in the cupboard over the closet?). But I also hold a railroad engineer's card, which is far more relevant here.
Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it...
Electroliner 1935 zugmann Nah, not important. Nothing that would impress you. Hell it doesn't even impress me. I don't really consider myself an academic, tbh. Ahh, another EUCLID. I thought better of you.
At least Zug can use the forum software properly when quoting people. Just sayin
Greetings from Alberta
-an Articulate Malcontent
I have railroad experience, some of it isn't very nice.
aother site says 91 & 92 / 10th will operate normal route. Guess that the 6 days of backup auto deliveries can start moving toward the site ?
So, what is a real world estimate of the sight distance?
Let's pretend for right now that this is straight level track, dark but clear. We can account for the curve from there.
Y'all are spending the time to claim Euclid doesn't know what he's saying but I haven't seen any other estimates
Modeling the Cleveland and Pittsburgh during the PennCentral era starting on the Cleveland lakefront and ending in Mingo junction
Maybe 10 car lenghtx in the dark, 15-20 car lengths in day light
ruderunnerY'all are spending the time to claim Euclid doesn't know what he's saying but I haven't seen any other estimates.
Sorry, I don't usually have a tape measure with me to verify how far I am from a switch when I can see the points.
Remember that the gap between the stock rail and the open points is only a couple of inches. If you're rolling down the railroad at speed it can be tough to see from any distance.
That said, I'd say a hundred yards or so. My eyes aren't as sharp as they used to be - although still well within the FRA requirements. Someone with "eagle eyes" might be able to spot it further out.
As for Bucky, he just admitted he likes to pull everyone's chain. I'll just leave that there.
so assuming passenger cars at roughly 85' werew looking at an 850 foot sight distance correct?
Or if you're referring to 40' boxcars then 400'.
That gives the engineer significantly more time to react, still not enough to prevent the collision but enough to minimize the impact by a significant amount.
That doesn't account for the curve reducing the sight distance. One can do the math to determine the actual sight distance reduction due to the curve but at this point Euclid doesn't seem too far off with his 250' estimate.
Thanks for the actual answer Randy.
Larry, 100 yards is 300 feet, less than one carlength difference from the estimate.
ruderunnerso assuming passenger cars at roughly 85' werew looking at an 850 foot sight distance correct? Or if you're referring to 40' boxcars then 400'.
Most freight folks these days think in terms of a 50 foot car, so that would put it around 500 feet, more or less.
No one has questioned the 250' figure. Only how much braking can occur in the three seconds that would elapse between seeing a misaligned switch and then reaching it at near 60 MPH.
tree68 ruderunner so assuming passenger cars at roughly 85' werew looking at an 850 foot sight distance correct? Or if you're referring to 40' boxcars then 400'. Most freight folks these days think in terms of a 50 foot car, so that would put it around 500 feet, more or less. No one has questioned the 250' figure. Only how much braking can occur in the three seconds that would elapse between seeing a misaligned switch and then reaching it at near 60 MPH.
ruderunner so assuming passenger cars at roughly 85' werew looking at an 850 foot sight distance correct? Or if you're referring to 40' boxcars then 400'.
23 17 46 11
As I said, I think 250 feet is a fair minimum, and it could be up to 500 feet or more. At night, an open switch shows a prominent black shadow in contrast to the headlight gleam on the rails. That shadow stands out because it diverges where the curved stock rail passes the open switch point. I have never measured the site distance, but on a railroad track, things look closer than they actually are.
Even in a curve, 250 feet is not going to bend very far, and is unlikely to cut off the view of the points.
I want to clarify something. Many times here, people have made the comment that you are not going to slow down much in 250 feet. Yes, ideally, the safest approch will allow you to stop before going into an open switch. But we are talking about braking in this particular collsion, and that involves the opjective of how much the train can be slowed in 909 feet.
As it was, the train slowed 6 mph in that distance; from 56 mph to 50 mph. Instead of going into emergency at 909 feet, it went into emergency at approximately 229 feet from the collision.
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