BaltACD CSSHEGEWISCH Zug would know this better than me but I do recall seeing Special Instructions in several Penn Central ETT's from 1969 that clearly state NOT to isolate traction motors in order to comply with restrictions. With the motive power of the 60's, as well as train size of the 60's it wasn't featured that locomotives could generate more tractive effort than knuckles and drawbars could withstand. Additionally there were no AC locomotives.
CSSHEGEWISCH Zug would know this better than me but I do recall seeing Special Instructions in several Penn Central ETT's from 1969 that clearly state NOT to isolate traction motors in order to comply with restrictions.
With the motive power of the 60's, as well as train size of the 60's it wasn't featured that locomotives could generate more tractive effort than knuckles and drawbars could withstand. Additionally there were no AC locomotives.
There were some long trains in the 1960s with 5-10 units. Pulling a drawbar was recognized as being quite easily done. I had not heard about cutting out traction motors to prevent pulling the train in two. But I do recall instructions calling for taking units off line during a backup move to prevent jacknifing. I assume that the preference for avoiding jacknifing as opposed to avoiding breaking a knuckle was that the former would probably cause more damage.
EuclidI assume that the preference for avoiding jacknifing as opposed to avoiding breaking a knuckle was that the former would probably cause more damage.
No, probably that pushing isn't geometrically 'stable' on the draft gear and vehicle dynamics, as pulling is, so there is inherently both a higher possibility of inducing a jackknife and then of driving it into full accordioning.
You, of all people on this forum, should be able to figure this out from first principles!
RME,
I am fully aware of the differnence in geometric principles and vehicle dynamics. Of course they are different in pulling than in shoving. So what? There is a risk damage in either pulling or shoving if too much force is applied.
It is the typical consequences of these mishaps that determines how much care should go into avoiding them. The consequences of pulling the train in two are a broken knuckle or a pulled drawbar. The consequences of shoving too hard are a derailement of one or more cars, which inflicts damage on the track and cars.
The differing vehicle dynamics produce the differing consequences. My citing of the consequences does not conflict with the facts of the vehicle dynamics.
I acknowledge that string lining can be a serious consequence of pulling too hard, but I set that aside to just consider the most likely consequences of too much pull or push.
Thanks once again, Mike !
That's what I thought this thread would be about . . . I learned it from a surveying text on Route Alignment, which is nowhere near as comprehensive as these articles. You can be sure this will be downloaded, saved, and printed ("We're all packrats in this business - George Harris of Parsons Brinckerhoff a few years back).
This is the method I prefer, and have achieved excellent results with it. The PRR used an entirely different method called the "bracket method" - maybe some others did too, but I'm not aware of them - but I felt it was too random/ trial and error. Once you figure out this method (took me until 2:00 AM one weeknight about 40 years ago until I had the "Eureka !" moment), it's much more analytical/ numerically predictive. Of course, in recent years it's been transferred to Excel spreadsheets which make the calculations almost instantaneous, and greatly shortened the time needed to do it. Also, though it seems primitive, if care is taken with the measurements, staking, and realignment, then better results can be obtained and faster than with most survey instruments (envision a curve in a rock cut or with vegetation on the inside), and certainly any GPS equipment.
Thanks again !
- Paul North.
You’re welcome, Paul, and thanks to the Army, the Navy and the Air Force.
https://archive.org/stream/ost-military-engineering-tm5_627/tm5_627#page/n0/mode/2up
Back in the days when we didn't have the current surveying tools, 1959-60, we ran the original line for the Williams- Crookton line change through rock canyons and cedar forests by using multiple PI's which provided us with the greatest accuracy as we were using 100' steel chains and new K&E 20" vernier transits.
The proceedure was to position the PI's at and near the final alinement by choosing a line of sight for short distances of 400-600 feet. Then moving the transit up and after backsighting the previous PI choose the next PI in similar fashion. When the next tangent was to be established the PT was staked and the calculations were made to determine angles and offset distances from each of the PI's to a PC (which obviously were random stations numbers).
Usually the field work was finished and calculations done at night, by the way W/O calculators with trig functions so we looked then up from our book of tables (mine was eight decimal places to seconds of a degree). Then the final alinement was staked the next day using the already established PC's. Ah, the good old days!!
More interesting data.Thank You.
From
http://www.tsb.gc.ca/eng/rapports-reports/rail/1996/r96c0172/r96c0172.asp
For the years 1991 to 1996, 190 runaways were reported to the TSB; 17 of these resulted in main track collisions and 5 resulted in main track derailments.
This does not seem to have gotten anyones attention prior to the TSB's hearing. 38/year. Was this considered bussiness as usual? Wonder how many this year?
This came up during the LacMegantic runaway discussion. I recall being surprised at how many runaways they have had in Canada in recent years. Because LacMegantic made the news, it made it seem like runaways might be unusual. That is anything but the case.
Lovely.
Thank You.
Is there a cause for these runaways that stands out as being most common? Are these runaway cars subject to handbrake securement rules and a push-pull test?
EuclidIs there a cause for these runaways that stands out as being most common? Are these runaway cars subject to handbrake securement rules and a push-pull test?
I would suspect that in most cases, runaways occur because of either a mechanical failure, or a human failure. A third possibility is human intervention.
Human failure would usually be failure to properly secure the car - not setting the brakes properly or not using other securing devices (chocks, skates, etc). Each carrier has their rules for securement testing. And failure to follow those rules would be an area of interest for anyone investigating a runaway.
Human intervention is a factor which often involves non-railroaders.
The Utica runaway, which ended up damaging an 0-6-0 switcher and part of Utica Union Station, was caused by a teen who released the brakes. We can presume that the car was properly secured according to guidance at the time. Since then, I believe skates have been employed.
A runaway from Fort Drum, NY a few years ago is thought to have been the result of soldiers lifting the cut levers on container flats. Nothing happened until a loader lifting a container onto one of the cars started the car moving. The two cars that rolled away were on the apex of a grade - and they rolled away from a long string of cars that were otherwise holding them in place.
It would not be beyond imagination for a customer to decide to move a car "a few feet" without realizing how little it takes for a car to really get moving.
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...
EuclidAre these runaway cars subject to handbrake securement rules and a push-pull test?
Operations in the era NDG and my father worked in are what led to entities like the TSB. New trainmen would be taught by conductors, but not very much if anything about those types of proceedures was codified.
I hope I didn't offend or step on anything NDG might want to say later.
Bruce
So shovel the coal, let this rattler roll.
"A Train is a Place Going Somewhere" CP Rail Public Timetable
"O. S. Irricana"
. . . __ . ______
NDGHere is another sad event on another sad anniversary. Not such a 'New Phenomenon' after all? http://www.ntsb.gov/investigations/AccidentReports/Reports/RAR0301.pdf Thank You.
"The National Transportation Safety Board determines that the probable cause of the May 28, 2002, collision at Clarendon, Texas, was (1) the coal train engineer's use of a cell phone during the time he should have been attending to the requirements of the track warrant his train was operating under and (2) the unexplained failure of the conductor to ensure that the engineer complied with the track warrant restrictions."
C&NW, CA&E, MILW, CGW and IC fan
Another sad incident.Thank You.
NDG9-12 Another sad incident.http://www.ntsb.gov/investigations/AccidentReports/Reports/RAR1001.pdfThank You.
Another sad incident.http://www.ntsb.gov/investigations/AccidentReports/Reports/RAR1001.pdfThank You.
What does the use of private communication devices have to do with 'string line' derailments or using the string line method of plotting out the path of a curve? The above incident has evolved to 3 letters - PTC.
Never too old to have a happy childhood!
The point is to inform.
NDG The point is to inform. Thank You.
If the point is to inform - hiding it in a thread about string line derailments isn't providing the information with the visibility it should have.
Assess Demerits for improper presentation, and I will sign for them.
Thank You, Sir.
BaltACD NDG 9-12 Another sad incident.http://www.ntsb.gov/investigations/AccidentReports/Reports/RAR1001.pdfThank You. What does the use of private communication devices have to do with 'string line' derailments or using the string line method of plotting out the path of a curve? The above incident has evolved to 3 letters - PTC.
NDG 9-12 Another sad incident.http://www.ntsb.gov/investigations/AccidentReports/Reports/RAR1001.pdfThank You.
What do string line derailments have to do with the string line method of plotting out the path of a curve?
Euclid What do string line derailments have to do with the string line method of plotting out the path of a curve?
CSSHEGEWISCH Euclid What do string line derailments have to do with the string line method of plotting out the path of a curve? They are spelled the same.
That must mean they are both part of the same theme.
NDG So much has changed since the 'Good' Old Days....
Ah, yes, those were the "Good" (?) Old Days. Loved reading your post.
ChuckAllen, TX
So string lining isn't limited to Lionel trains on 027 curves?
Modeling the "Fargo Area Rapid Transit" in O scale 3 rail.
No, it can happen with all scales of railroading. Here is a video that showes it in action. That light cable visible in the foreground is not the pulling cable, but it appears that way. The actual pulling cable is hardly visible since it is down in the dirt, and connected to the drawbar.
https://www.youtube.com/watch?v=FW8ecqxG8NY
If you look closely, you can see the puff of smoke indicating widening the throttle. The added power causes the misaligned pull to force the flanges to climp the rail and derail the truck. The derailed truck slides sideways a couple feet, and drops off of the ties. Then the locomotive upsets.
NDG FYI.13 loads from siding hit manned train @ 56 MPH, w/photos.http://www.tsb.gc.ca/eng/rapports-reports/rail/2012/r12e0004/r12e0004.aspThank You.
FYI.13 loads from siding hit manned train @ 56 MPH, w/photos.http://www.tsb.gc.ca/eng/rapports-reports/rail/2012/r12e0004/r12e0004.aspThank You.
I remember that one, happened in my area shortly after I qualified as a Conductor. Very scary, I later wound up working on the Grande Cache sub for a while and met a couple of the guys who were involved. Was told that a major reason the Engineer Trainee survived the crash was that he was quite obese (haven't seen him for a few years, he was nearly as wide as he was tall) and all the fat kinda sorta cocooned and cushioned him from the impact. Made getting him out much harder though.
Greetings from Alberta
-an Articulate Malcontent
String Lining could also mean 'Stringing a Line' as in distorting reality to fit the needs of the problem at hand, from Pure Laine to Pure Bull, and so on?This could be a Laine Impure thread as it as already been corrupted according to onboard experts??My! THOSE Meds are wonderful!!!Thank You.
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