Trains.com

String Lining

228320 views
2898 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    May 2003
  • From: US
  • 24,740 posts
Posted by BaltACD on Tuesday, September 13, 2016 2:07 AM

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.  

Never too old to have a happy childhood!

              

NDG
  • Member since
    December 2013
  • 1,588 posts
Posted by NDG on Tuesday, September 13, 2016 1:53 AM

The point is to inform.

Thank You.

  • Member since
    May 2003
  • From: US
  • 24,740 posts
Posted by BaltACD on Monday, September 12, 2016 11:02 PM

NDG

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!

              

NDG
  • Member since
    December 2013
  • 1,588 posts
Posted by NDG on Monday, September 12, 2016 10:20 PM



Another sad incident.


Thank You.

  • Member since
    July 2006
  • 9,610 posts
Posted by schlimm on Monday, September 12, 2016 7:51 PM

NDG
Here 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

NDG
  • Member since
    December 2013
  • 1,588 posts
Posted by NDG on Monday, September 12, 2016 4:25 PM



Thank You.

 

 

  • Member since
    August 2008
  • From: Calgary AB. Canada
  • 2,298 posts
Posted by AgentKid on Monday, September 12, 2016 11:55 AM

Euclid
Are 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"

. . . __ . ______

  • Member since
    December 2001
  • From: Northern New York
  • 24,773 posts
Posted by tree68 on Monday, September 12, 2016 9:08 AM

Euclid
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?

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.  

 

LarryWhistling
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...

  • Member since
    January 2014
  • 8,102 posts
Posted by Euclid on Sunday, September 11, 2016 11:07 PM

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?

NDG
  • Member since
    December 2013
  • 1,588 posts
Posted by NDG on Sunday, September 11, 2016 10:43 PM

Lovely.

 

Thank You.

  • Member since
    January 2014
  • 8,102 posts
Posted by Euclid on Sunday, September 11, 2016 7:14 PM

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. 

  • Member since
    September 2010
  • 2,515 posts
Posted by Electroliner 1935 on Sunday, September 11, 2016 5:23 PM

 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?

NDG
  • Member since
    December 2013
  • 1,588 posts
Posted by NDG on Sunday, September 11, 2016 3:16 PM

 

More interesting data.

Thank You.

  • Member since
    December 2006
  • 1,715 posts
Posted by diningcar on Tuesday, August 30, 2016 11:05 AM

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!!

 

  • Member since
    November 2005
  • 4,190 posts
Posted by wanswheel on Tuesday, August 30, 2016 10:32 AM

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

 

  • Member since
    October 2006
  • From: Allentown, PA
  • 9,810 posts
Posted by Paul_D_North_Jr on Monday, August 29, 2016 8:49 PM

Thanks once again, Mike !  Bow

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.

"This Fascinating Railroad Business" (title of 1943 book by Robert Selph Henry of the AAR)
  • Member since
    November 2005
  • 4,190 posts
Posted by wanswheel on Monday, August 29, 2016 12:22 PM

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  • Member since
    January 2014
  • 8,102 posts
Posted by Euclid on Monday, August 29, 2016 11:26 AM

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. 

RME
  • Member since
    March 2016
  • 2,073 posts
Posted by RME on Monday, August 29, 2016 11:08 AM

Euclid
I 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!

  • Member since
    January 2014
  • 8,102 posts
Posted by Euclid on Monday, August 29, 2016 10:51 AM

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.

 

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. 

  • Member since
    May 2003
  • From: US
  • 24,740 posts
Posted by BaltACD on Monday, August 29, 2016 10:40 AM

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.

Never too old to have a happy childhood!

              

  • Member since
    November 2013
  • 1,097 posts
Posted by Buslist on Monday, August 29, 2016 10:12 AM

RME

 

 
NDG
An Incident Report re String Lining.

 

 

 

I also note -- trusting it will not be abused -- that the track across the bridge is indicated as being on rolled plates with flexible securement (I take this to be Pandrol fixation on wood ties, as at Fabyan Bridge) and no rail anchors.  I am not sure how that could be, and I look forward to someone explaining more about trackwork on the Connaught Tunnel section.

 

 

THAT is one of the major selling points of elastic rail clips. Pandrol, and other brand, elastic clips are designed to maintain a toe load between the clip and the top of the rail base. That toe load provides enough friction to prevent longitudinal rail movement. The savings in the lack of the requirement for rail anchors partially offsets the higher cost of the spring clip system. The ability to change out rail without spike killing ties is also considered a major factor.

  • Member since
    March 2016
  • From: Burbank IL (near Clearing)
  • 13,432 posts
Posted by CSSHEGEWISCH on Monday, August 29, 2016 7:39 AM

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.

The daily commute is part of everyday life but I get two rides a day out of it. Paul
  • Member since
    May 2003
  • From: US
  • 24,740 posts
Posted by BaltACD on Sunday, August 28, 2016 10:40 PM

zugmann
BaltACD

A very gray area.  Many engines only allow you to cut out a whole truck, while a lot of older engines had their individual motor cut out switches removed on my road. 

I've heard that traction motors should only be cut out if defective, and not to comply with axle restrictions.  Depends on which road foreman you ask on which day.  Maybe you company's book spells it out better.

On my carrier, for compliance with train handling rules, both GE and EMD 6 axle AC traction locomotives are counted as 9 axles.  DC traction locomotives count axle for axle.  GE AC's permit cutting out individual axles.  EMD AC's only permit an entire truck to be cut out.

Maximum tonnage for a territory is calculated as the tonnage rating of 3 GE Dash-8's for non-bulk commodity trains.  Bulk commodity trains maximum tonnage is calculated as the tonnage rating of 2 GE AC's + 1 Dash-8.  Once one starts adding in either manned helpers and DPU, different calculations get applied.

Today's locomotives with their horsepower and advanced wheel slip prevention easily have the ability to exceed the designed strength of knuckles and drawbars when too many units are on line on the head end of a train.

Each carrier has their own rules concerning how much power of what kind may be on the head end of a train and how to calculate it.

Never too old to have a happy childhood!

              

  • Member since
    January 2002
  • From: Canterlot
  • 9,473 posts
Posted by zugmann on Sunday, August 28, 2016 9:30 PM

BaltACD
Individual traction motors on locomotives can be removed from electrical loading by the crew when necessary to comply with rules. Restoring a traction motor to loading that had previously been cut out would be considered having it 'cut in' again.

A very gray area.  Many engines only allow you to cut out a whole truck, while a lot of older engines had their individual motor cut out switches removed on my road. 

I've heard that traction motors should only be cut out if defective, and not to comply with axle restrictions.  Depends on which road foreman you ask on which day.  Maybe you company's book spells it out better.

  

The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.

RME
  • Member since
    March 2016
  • 2,073 posts
Posted by RME on Sunday, August 28, 2016 9:09 PM

BaltACD
With the accident happening when it did, if the unit was being handled 'dead in tow' without the prime mover operating, it most likely would have had it's coolant drained

I'm assuming the prime mover was operating or hotstart-enabled; the incident was in the middle of January and there is visible snow at the accident site.

The thing is that the formula for TrAM uses equivalent axles (which I think translates into something like 10,000lb TE for each) but cutting out one traction motor (of the 12 available on 2 operating units) wouldn't decrease the number of equivalent axles by only one, from 24 to 23, as indicated.  Which is why I wondered whether the third unit had been taken out of isolation to allow its motored axles to contribute, but since the computer limit for that train showed as 23, one TM was kept isolated.  Since evidently the derating could be easily and quickly reversed from the operating cab (they cut it in to try starting the train) I suspect we may be seeing computer HP degrading in the electrical system and not an actual motor cutout ... but that's not what the TSB says.

  • Member since
    June 2003
  • From: South Central,Ks
  • 7,123 posts
Posted by samfp1943 on Sunday, August 28, 2016 8:45 PM

RME

 

 
AnthonyV
What is meant by "cut in the 24th driving axle"?

 

It's in the report.  In order not to exceed permissible 'pull' on the train, the engine crew derated the consist by cutting out one traction motor, hence the '23 axles' going up the grade.  When the train stalled, the crew was given authorization to cut that additional motor back in to try to get the train moving.

 

This is an area where I need some help: "equilevent axle" ?

I am sure it has a logical explanation.   From the Official Accident Report:[ section as indicated.]             [snipped]   Factual information

"...On 13 January 2015, Canadian Pacific Railway (CP) Train 199-10 (train 199), originating in Field, British Columbia, was travelling westward on the Mountain Subdivision, destined for Vancouver, British Columbia. The train consisted of 3 head-end locomotives and 43 cars (20 loaded cars and 23 empty cars, totalling 111 platformsFootnote 1). The train weighed about 4775 tons and was 6812 feet long..."[snipped]

and then from the following section; [snipped]Equipment information

"...The 3 locomotives on train 199 were GE 4400 horsepower 6-axle units. The locomotives were in serviceable condition, with the third unit isolated..."

So, train 199 had three engines with one unit'isolated'... So, effectively, only TWO engines were powering the train, the third, in isolation.

Later the crew reports that they have 24 equivalent axles, and will isolate another equivalent traction motor; now down to 23 traction motors, to meet regulations for their 'TrAM #' (?)

From Report[snip] "...As indicated in CP's General Operating Instructions (GOI) and highlighted in the Train Area Marshalling (TrAMFootnote 3) messages for TrAM Area 5 on the crew's train consist, the crew reduced the equivalent driving axlesFootnote 4 from 24 to 23 by cutting out a traction motor on 1 of the operating locomotives..."[snipped]

The locomotives were, as stated GE's (4400HP,each) 6 axles per unit.  Back to the 24 equivalent axles....?

Is the isolated unit being counted?

How many equivalent axle units per locomotive?

Why would the crew [or THE  RTC] not request the'isolated' unit be used, when the Accident report clearly states the THREE units were servicable? 

Would using the 'isolated unit' have allowed the train to continue up the grade?

 

 

 


 

  • Member since
    May 2003
  • From: US
  • 24,740 posts
Posted by BaltACD on Sunday, August 28, 2016 8:18 PM

RME

I need a little remedial railroad English from someone familiar with CP rating systems and TrAM.  The consist was three 4400hp GEs, but the third unit was described as 'isolated' (meaning, I thought, dead in transit as far as its motors were concerned) but it was possible to adjust power from 24 to 23 equivalent axles "by cutting out one traction motor".  I can see this working if all three engines were motoring at that point (which might be expected if the ruling grade had effectively been changed from 1.25 to nearly double that by the redirection) but nowhere do I see an indication that the third locomotive was itself fired up and cut in.

Isolated is a term that is used when the locomotive has it's prime mover operating but the locomotive itself is not being used for on line power.  With the accident happening when it did, if the unit was being handled 'dead in tow' without the prime mover operating, it most likely would have had it's coolant drained as it would have frozen up without being either drained or operating with a 'Hot Start' or similar system to keep the coolant in the prime mover warm.

Never too old to have a happy childhood!

              

  • Member since
    January 2014
  • 8,102 posts
Posted by Euclid on Sunday, August 28, 2016 8:02 PM

That photo of the derailment looks rather abstract.  Apparently it shows the tops of the bents all kind of torn up.  Apparently the background looking downward is several hundred feet beyond the bridge details.  But in the photo, the background does not seem distant.  It would be very interesting to learn exactly what happened as this wreck unfolded.   

RME
  • Member since
    March 2016
  • 2,073 posts
Posted by RME on Sunday, August 28, 2016 7:29 PM

Some more notes:

For the record, this is what the bridge looks like from a distance (train shown is eastbound, so the 'looking west' in the following picture shows the 'west abutment' where the power came to a stop)

and this is the picture from the report that shows the stringlined cars on the bridge

Darned if I can reconcile the visible curvature in these pictures with the direction of the stringlining, but the report's details suggest to me that the stringlining was actually comparatively close to the locomotives.  Is there any comment in the report or its appendices as to what positions in the train the derailed cars were?  And whether the single well car that derailed was leading or trailing the 5-unit car that is pictured?  (Note that CP considers all units of an articulated well car to be one "car" for consist purposes, before anyone starts wondering how a 43-car train could be over 6800')

 

I need a little remedial railroad English from someone familiar with CP rating systems and TrAM.  The consist was three 4400hp GEs, but the third unit was described as 'isolated' (meaning, I thought, dead in transit as far as its motors were concerned) but it was possible to adjust power from 24 to 23 equivalent axles "by cutting out one traction motor".  I can see this working if all three engines were motoring at that point (which might be expected if the ruling grade had effectively been changed from 1.25 to nearly double that by the redirection) but nowhere do I see an indication that the third locomotive was itself fired up and cut in.

 

Join our Community!

Our community is FREE to join. To participate you must either login or register for an account.

Search the Community

Newsletter Sign-Up

By signing up you may also receive occasional reader surveys and special offers from Trains magazine.Please view our privacy policy