Carl - many years ago stringlining was explained, but I have forgotten what it is.
Could you or someone explain again to me and anyone else that forgot or doesn't know - what happens?
She who has no signature! cinscocom-tmw
Take a piece of string and form it in an arc on the table. Pull the ends.
With a train and a sharp curve, pulling too hard on one end with too much resistance on the other will do the same thing, except it's railroad cars getting pulled over...
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...
Mookie Carl - many years ago stringlining was explained, but I have forgotten what it is. Could you or someone explain again to me and anyone else that forgot or doesn't know - what happens?
Thanks to Chris / CopCarSS for my avatar.
[quote user="Murphy Siding"
ps Happy Birthday! (And Merry Christmas. Is it ok if I get you a combination birthday and Christmas gift again? . pss working on the Christmas letter.)
[/quote] Combine them and I know where to get a whole gon of coal for your sock drawer. But if you could include a little chocolate cake in letter....
When this stringlining occurs, is there a specific cause - like weather, rail condition, speed, anything an engineer can do to keep this from happening...(I hesitate to say bad train handling)
Mookie Murphy Siding ps Happy Birthday! (And Merry Christmas. Is it ok if I get you a combination birthday and Christmas gift again? . pss working on the Christmas letter.) Combine them and I know where to get a whole gon of coal for your sock drawer. But if you could include a little chocolate cake in letter....
Murphy Siding ps Happy Birthday! (And Merry Christmas. Is it ok if I get you a combination birthday and Christmas gift again? . pss working on the Christmas letter.)
Mookie When this stringlining occurs, is there a specific cause - like weather, rail condition, speed, anything an engineer can do to keep this from happening...(I hesitate to say bad train handling)
Just saw a picture of a bunch of aluminum hoppers at the bottom of the hill having been stringlined on a 10 degree curve (pretty sharp in railroad terms).
As with my string example, you need something pulling on both ends. Too much power, heavy loads at the other end (with the aforementioned empty cars), brakes released on the front but not on the rear (and power applied), a significant grade - any of them could combine to cause the problem.
Normally, long, empty cars are involved in 'stringline' derailments. The tonnage of the train that is behind the long empties creates the 'drag' that overstresses the empties ability to stay on the rail.
Never too old to have a happy childhood!
Wow - a picture and lots of words (probably not printable)
Thanx Balt. This I can understand.
BaltACD Mookie When this stringlining occurs, is there a specific cause - like weather, rail condition, speed, anything an engineer can do to keep this from happening...(I hesitate to say bad train handling) Normally, long, empty cars are involved in 'stringline' derailments. The tonnage of the train that is behind the long empties creates the 'drag' that overstresses the empties ability to stay on the rail.
Stringlining was also a frequent cause of derailments involving piggyback cars. I remember a derailment in 1969 on the CWI at the 130th Street curve. The curve was superelevated and I suspect some less than ideal train handling led to the slack being pulled out and the piggyback cars went right on their side inside the curve.
Glad that stringlining was explained to your satisfaction, SJ.
Center-beam flat cars are far and away the worst offenders here. They're heavier on top than most other cars of that height, and the other cars have heavy underframes to lower the center of gravity, which Center-beams do not (the partition itself takes the place of the underframe in making the car rigid under load).In my experience, the curves that are the sites of stringline derailments eventually find themselves rebuilt in some way, if possible.
Carl
Railroader Emeritus (practiced railroading for 46 years--and in 2010 I finally got it right!)
CAACSCOCOM--I don't want to behave improperly, so I just won't behave at all. (SM)
The string-lining Carl described often has a train handling component to to it and usually it is slack action acting as the trigger as the drawbars run in and out.
Trackmen have another version of stringlining that they are all to familiar with which involves measurements based on 31 and 62 foot chords. The FRA rules are based on this and the track guys use stringlining because us mudchickens often aren't handy when ya need 'em. (Using a 62 foot string, if you measure the mid-ordinate at 31 feet on the string (the distance from the string over to the gage corner of the ball of the rail) in inches, you get the degree of curve. For the ten degree curve mentioned above would have a 10 inch distance between the string and the gage corner of the rail. (Radius?.... REAL railroaders don't need no stinkin' radius! )
(Murphy: We've been trying to pay off the Cat on an installment plan. At the rate I'm going, the cat is gonna have a lifetime supply of chocolate cake. ... )
Good explanation MC, but lacking one factor. Are the ends of the string on the gage side of the rail head or the field side?
Norm
Yes.
Ns was clear when I left work.I would think autoracks would be cars to tip over on sharp curves as well.Matt and I are going to a Christmas concert. Will see what CSX has running (or waiting to get to Garrett.)
stay safe
Joe
Deshler Ohio-crossroads of the B&O Matt eats your fries.YUM! Clinton st viaduct undefeated against too tall trucks!!!(voted to be called the "Clinton St. can opener").
CShaveRR Yes.
Johnny
Gage side, high/outside rail at all three places. (otherwise the middle of the string gets snagged or hung up on the rail which can create false measurements)....Field side on the low rail would generate a similar number, but it isn't the actual running surface corner.
The stringline concept, albeit modified, is how the big curve liners work as well.
DiningCar, PDN and I have strungline* more than we would like to admit and then gone through the repetitive brain damage of mathematical iteratively balancing the "throws" to smooth a curve...
While stringlining has its issues, it often is all you have when the surveyors are elsewhere on something more pressing. Some old head track side Division Engineers and above wanted stringlining to the exclusion of a surveyed solution.
(*) real verb? Spel-czech might fry a processor on that one.
mudchicken (Radius?.... REAL railroaders don't need no stinkin' radius! )
Yeah, but the ulna will be really lonesome without it.
And I thought Carl was a retired railroader--or is that why he is retired?
Ahem: stringlined.
Thanks, MC. I'm sure the Cat thanks you, too.
ChuckCobleigh mudchicken (Radius?.... REAL railroaders don't need no stinkin' radius! ) Yeah, but the ulna will be really lonesome without it.
mudchicken (Murphy: We've been trying to pay off the Cat on an installment plan. At the rate I'm going, the cat is gonna have a lifetime supply of chocolate cake. ... )
Dan
Haha! I'm sure you'd "have to" let us, wouldn't you?
Glad some things never change.
Well I'm no good at making choclate cake. One of the few things I can make that's actually pretty darned good is lasagna. Anybody know the current exchange rate from chocolate cake to lasagna?
short eastbound stacker on Ns when I left work.Time to go go go.
Murphy Siding Well I'm no good at making choclate cake. One of the few things I can make that's actually pretty darned good is lasagna. Anybody know the current exchange rate from chocolate cake to lasagna?
Cat has quite a franchise going there in Nebrasky. The Oracle would certainly approve.
evening
Ns was clear when I left work.Got word CSX decided to pick a switch in Fostoria today.It's Friday tomorrow.Guessers say highs in the 60's this weekend.
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