String Lining.

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RME
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Posted by RME on Sunday, August 28, 2016 8:30 AM

NDG
An Incident Report re String Lining.

Wow!

The more you read this report, the more things jump out at you.  In a way, this is an even more dramatic concatenation of small decisions into ultimately inevitable disaster than Lac Megantic.  (Again, a couple of the more fascinating aspects being a RTC making really bad decisions, and insufficient training or policy.)

Note the very small changes in so many things that would have solved this "before it happened" -- and the understating of the forces involved.  (I will take a risk here, and note that a good derailment detector with notice to the train crew would have identified the stringlining while still going uphill with the 24th traction motor cut out.)

Something that isn't identified in the report is precisely what happened after the train started backing down.  I read between the lines a bit to speculate that the resistance of the stringlined derailed cars exceeded the gravitational potential of the train behind the derailment point, and the crew applied backing power to get the reverse move started more briskly down to wherever they were going to start their 'run' on the grade, but in the picture I see, the well cars appear to be still visibly stringlined.  Is there a picture of the point at which the air line actually parted?

Reading this, I was not impressed with fobbing off notification of TrAM violations on the crew, when so clearly providing both the relevant information and a computer program to analyze it to the RTC environments is so simple and straightforward.  (The business with converted AEIs further confirms this to someone with knowledge of data harmonization.)

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.

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Posted by Euclid on Sunday, August 28, 2016 1:19 PM

It sounds to me as if there was a fatigue problem when writing this report.  There is no indication that this string lining occurred as the train was pulling up the grade.  So where did the tensile force come from that caused the string lining?

From the report:

“While operating past Fraine towards Stoney Creek, train 199 continued to lose speed as it climbed the grade. At 0505, the train crew advised the RTC that they were at Mile 76.6 and that train speed was now at 1 mph owing to the steep grade. Shortly thereafter, the train came to a stop on a 8.75-degree right-hand curve, with the head end of the train at the west-end bridge abutment of the Stoney Creek Bridge. To continue up the grade, it was decided to cut in the 24th driving axle. After an unsuccessful attempt to pull the train up the hill, the RTC issued train 199 a Rule 577. Train 199 was therefore authorized to back up (that is, down the hill) until it was on a tangent track where the grade was not as steep. The train would then make another attempt at cresting the grade.

As the train was backing up, an undesired emergency brake application occurred. Once the train came to a full stop, the conductor exited the locomotive to inspect the train. It was determined that 6 platforms from 2 empty intermodal flat cars had derailed on the Stoney Creek Bridge. The crew advised the RTC of the situation. There were no injuries, and no dangerous goods were involved.”

 

This description sounds as if the train derailed when backing down the grade.  The “undesired emergency application” occurred as the train was backing down the grade.  When it stopped, the conductor walked back and found the derailment.  Presumably, the U.D.E. was caused by the derailment.    

 

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Posted by Paul of Covington on Sunday, August 28, 2016 1:25 PM

   How would you recover the equipment in that location?   I don't see how you could get any heavy equipment to it.   I was also thinking "just cut 'em loose" and let them fall, but it's my understanding that you can't release couplers if they are under tension, and if you were able to release them, you'd have to release both ends simultaneously to keep them from pulling more cars down.  Maybe I'm thinking about this too much.  

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Posted by cx500 on Sunday, August 28, 2016 1:30 PM

The report does not specifically identify when the cars stringlined.  I wonder if they had already derailed when the train stalled, then the air line finally broke as the back-up move added to their displacement.

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Posted by AnthonyV on Sunday, August 28, 2016 1:48 PM

Euclid

It sounds to me as if there was a fatigue problem when writing this report.  There is no indication that this string lining occurred as the train was pulling up the grade.  So where did the tensile force come from that caused the string lining?

If the train was still on the grade, the tensile force exists whether the train is moving forward or backward.  At these low speeds, the tensile forces are essentially the same if the train is not accelerating, and could go to zero only if the train was in free-fall.

Anthony V.

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Posted by Euclid on Sunday, August 28, 2016 2:08 PM

AnthonyV
 
Euclid

It sounds to me as if there was a fatigue problem when writing this report.  There is no indication that this string lining occurred as the train was pulling up the grade.  So where did the tensile force come from that caused the string lining?

 

 

If the train was still on the grade, the tensile force exists whether the train is moving forward or backward.  At these low speeds, the tensile forces are essentially the same if the train is not accelerating, and could go to zero only if the train was in free-fall.

Anthony V.

 

I can see that there would be a high tensile force if a train were standing on a grade with the automatic brake released and holding the train with just the independent brake.  I wonder if that alone has ever caused a string line derailment.  I always associate the excessive force that causes a string line derailment as being caused by the pull of the locomotive against just the inertia of the cars during accelertion; or by pulling against the resistance of a rising grade. 

But if this derailment was caused by the gravitational tensile pull of the train, I don't clearly see what circumstances led to that outcome.  In backing down the grade, the train would have to be restrained by braking.  Automatic brakes would apply to all cars, so fundamentally, there would be no tensile stress. 

However, if they were restraining the descending train with dynamic brakes, then there would be considerable tension in the train, particularly if the dynamic brake force were increased at any point during roll back down the hill.  Is that what happened?  Was the tension caused by dynamic braking against the pull of the train during the backing down the grade?

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Posted by RME on Sunday, August 28, 2016 2:33 PM

The report clearly says that the stringlining occurred pulling uphill, likely BEFORE the 24th traction motor was cut back in.  They hypothesize that the train stoppage was actually caused by the increased resistance of the stringlined cars, not the steeper grade.  I did not see any discussion of how long the train was in the process of 'pushing back' before the unexpected brake application, or what the actual failure that caused this application was; both are moot given the issue.

It might be interesting to go back retrospectively and consider whether any aspect of the flexible rail securement system might have contributed to this incident.

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Posted by Semper Vaporo on Sunday, August 28, 2016 2:41 PM

I think maybe the U.D.E. caused the derailment... the train was stopped and the brakes were released so that it could start backing down the grade.  The Engineer started backing the headend engines before the brakes on the rear cars were fully released so the train started to bunch.  Then the rear cars started moving as the brake releasing drop in pressure reached them.  Because there is no "gradual release" of train brakes and the rear cars are on a downgrade they are rolling free.  Some car toward the head end dynamites and causes loss of brake pipe pressure, re-applying the brakes on the cars, but the propagation delay along the train line causes the cars at the head end to stop, but the cars at the rear are still rolling free and have enough momentem and weight to string-line the empty well-cars on the curve.

Semper Vaporo

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Posted by AnthonyV on Sunday, August 28, 2016 3:07 PM

Euclid

 

 
AnthonyV
 
Euclid

It sounds to me as if there was a fatigue problem when writing this report.  There is no indication that this string lining occurred as the train was pulling up the grade.  So where did the tensile force come from that caused the string lining?

 

 

If the train was still on the grade, the tensile force exists whether the train is moving forward or backward.  At these low speeds, the tensile forces are essentially the same if the train is not accelerating, and could go to zero only if the train was in free-fall.

Anthony V.

 

 

 

I can see that there would be a high tensile force if a train were standing on a grade with the automatic brake released and holding the train with just the independent brake.  I wonder if that alone has ever caused a string line derailment.  I always associate the excessive force that causes a string line derailment as being caused by the pull of the locomotive against just the inertia of the cars during accelertion; or by pulling against the resistance of a rising grade. 

But if this derailment was caused by the gravitational tensile pull of the train, I don't clearly see what circumstances led to that outcome.  In backing down the grade, the train would have to be restrained by braking.  Automatic brakes would apply to all cars, so fundamentally, there would be no tensile stress. 

However, if they were restraining the descending train with dynamic brakes, then there would be considerable tension in the train, particularly if the dynamic brake force were increased at any point during roll back down the hill.  Is that what happened?  Was the tension caused by dynamic braking against the pull of the train during the backing down the grade?

 

Good points Euclid.

My reply was based on the assumption that the dynamics were being used during the reverse move.  If this was the case, I cannot see how the coupler forces would be significantly different going up or down grade.

As you point out, if the automatic brakes are applied during the reverse move, the tensile forces would clearly be less than those during the uphill move.

Anthony V.

 

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Posted by Euclid on Sunday, August 28, 2016 3:10 PM

RME

The report clearly says that the stringlining occurred pulling uphill, likely BEFORE the 24th traction motor was cut back in.  They hypothesize that the train stoppage was actually caused by the increased resistance of the stringlined cars, not the steeper grade.  I did not see any discussion of how long the train was in the process of 'pushing back' before the unexpected brake application, or what the actual failure that caused this application was; both are moot given the issue.

It might be interesting to go back retrospectively and consider whether any aspect of the flexible rail securement system might have contributed to this incident.

 

Okay, I see the clarification under the section called "The Accident".  The train string lined just before stalling while pulling up grade.  The air stayed connected, so they did not realise they were on the ground.  Then upon reversing to back down the grade, the string lined, derailed cars apparently jacknifed and parted the air line, thus causing the "Emergency" application, which they refer to as an undesired emergency application.  Then the conductor went back and found the derailment. 

So it was actually a derailment that occurred in two separate stages.  One stage was string lining going up the grade, and the other was jacknifing while backing into the derailed string lined cars while attempting to back down the grade for another run at it with the 24th traction motor cut back in.   

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Posted by RME on Sunday, August 28, 2016 3:42 PM

Euclid
So it was actually a derailment that occurred in two separate stages. One stage was string lining going up the grade, and the other was jacknifing while backing into the derailed stringlined cars while attempting to back down the grade for another run at it

No, because I see no indication of jackknifed cars at all, and even a little tension release would likely cause some of the well cars in the illustration to fall.

I got a pretty good laugh out of the TSB working their 'angled coupler' logic for a bunch of articulated well cars, the antithesis of long cushioned-underframe draft gear angularity... might be interesting to conduct a modeling of the mechanics of stringline derailment on the leading vs. trailing wheels (larger diameter) of the intermediate articulated three-piece trucks in these well car sets.

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Posted by NDG on Sunday, August 28, 2016 4:20 PM

 

So much has changed since the 'Good' Old Days.

Back in the day, before Train Radio, when you knew you were not going to make it and a 'Stall' was imminent. The tail end knew, without Radio, as Wheel Slip would accordion thru the train, jerking the Caboose along in steps account Slack.

You would not fool around very long, and just Double.

The Conductor or Tail End Man would be dropping Red Fusees if Tail End not provided, and get ready to 'Go Flagging' checking Flagging Kit for requisite amount of Red Fusees and Torpedoes, and Red Cloth Flag on a Staff. Many Flagging Kits also carried wooden matches, Just in Case.

The Head End Trainman would check, and then Light, a Clear-Globe 'White' Coal Oil Lamp ( Adlake Kero ) from the nose and get ready w/ clothing etc. against Weather, and take a few Fusees and Track Torpedoes. In addition to his battery Trainman's lamp

When this happened, it was ALWAYS in middle of Dark, Pouring Rain, or Snowing, with Grizzlies' eyes red in the lamp light.  Bears LOVED trains, as spilt grain attracted 'Game' and trains killed same. Bears would eat spilt lading such as wheat, corn, etc.

If unit still had some Traction, AMPS would be in Red, sand would be gone, and it was time to quit. The sizzle of spinning drivers from below, twin exhausts roaring to the sky, if OP, and flinging glowing carbon chips.

Speed about 5 MPH. DC Power, F-M and Westinghouse against Gravity.

Engineer would say 'Go' and you got off, looking at the sparks to the smell of hot motors.. Less far to walk if you got off while still moving, esp. in DEEP Snow.  Bridges did not yet all have walk ways, either.

He would Whistle out a Flag, if necessary.

It had been decided how many cars to take up, 10 or maybe 20 cars to the next siding above the grade.

When you were at that count he set the air, then pushed back to get the pin, head end visible answering hand lamp signals.

You then moved him ahead slowly, placed lit white oil lamp on the drawbar of the first car left and, as he moved, placed Torpedoes in advance for when backing down w/power later.

The Conductor would be walking up w/ lamp and fusees.

If Whistled Out, the Rear Trainman would start walking back to Flag as per Rule 99.

You'd pull first cut to siding, hope switch was NOT full of Snow. If it was, you dug it out, and swept the points. and back in to clear, setting a brake or two as you went in, then run lite back down to train.

By then the Conductor would be there, have a red fusee lit as you exploded the guns, and make the joint.

Whistle in the Flag, if sent out, Pump Up, and Pull, leaving Red Fusees.

The Conductor would watch train by, get on Caboose, and, if Trainman NOT back from Flagging, stop movement. Maybe a Bear got him??

( One train, while Doubling, the rear end released and took off, killing the Trainman walking back in the snow and wind.)

Pick up first cut and add to train.

Fairly Simple.

Straight forward.

Some runs Doubling was the NORM, rather than add extra power for one hill, if time not important.

Some runs were steep w/ tight curves, and more power would just cause string lining, so Doubling the way out.

Now, the crux, Like Megantic. ( The town was named Lac Megantic as per adjacent Lac. )

WHY weren't TRAIN Hand Brakes Applied sufficient to hold train?

We put on TONS of Brakes against 2% and MORE, and took them OFF, too. Some cars did NOT have the 'Dog' to kick them off, and were a female dog to get off.

Sometimes if cars were in Emergency 'big guys' would really wrap on a good brake w/300 pounds of Muscle, fewer Beer Guts in the BoRT before radio, and the next guy along could not get it OFF.

The usual fix was to charge the car, walk ahead to next angle cock, and Dynamite the car. Then, maybe, the piston would have taken much of the tension off.

Sometimes one had to go to the Caboose or Engine and get a hammer and chisel and knock the cotter key and pin out on the rigging, then reassemble.

Big groans all around at the delay.

At Stoney Creek, MAYBE DOUBLING should have been considered??

I assume the flats had solid drawhars as 'Packs' ergo did not fall.

Flats NEXT to the Engines, in the MOUNTAINS??

Great ahead of the Caboose, so you could see!

Not so great in winters, as wind of movement really blew in the cracks.

Most Cabeese had storm doors, held open with a gravity latch when not required

Seems as if the old ways are forgotten, sometimes??

If a hammer works, why try and get an App on one's Tablet to do it? If the Rules Allow it's use on duty?

Just some thoughts.

B B B

Thank You.

Its almost 1430. Time for my usual 10-mile 4-8-2 bike ride.

A funeral every month, these days.
 
March a good Month for Contributors? Tho'.
 

   

 

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Posted by BaltACD on Sunday, August 28, 2016 4:32 PM

NDG
Seems as if the old ways are forgotten, sometimes??

The 'old ways' are unknown today, not forgotten they aren't even known.

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Posted by AnthonyV on Sunday, August 28, 2016 4:35 PM

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

Thanks.

Anthony V.

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Posted by BaltACD on Sunday, August 28, 2016 4:40 PM

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

Thanks.

Anthony V.

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.

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Posted by RME on Sunday, August 28, 2016 4:40 PM

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.

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Posted by AnthonyV on Sunday, August 28, 2016 4:57 PM

Thanks guys.

Yes, it is in the report.  I don't have any idea how I missed it.

Anthony V.

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Posted by Euclid on Sunday, August 28, 2016 5:12 PM

RME
 
Euclid
So it was actually a derailment that occurred in two separate stages. One stage was string lining going up the grade, and the other was jacknifing while backing into the derailed stringlined cars while attempting to back down the grade for another run at it

 

No, because I see no indication of jackknifed cars at all, and even a little tension release would likely cause some of the well cars in the illustration to fall. 

I was only referring to jacknifing to the extent that it took to part an air hose.  But I see your point that upon shoving back, a car may have just dropped out of the string and fell, which caused an air hose to part.  However, the string lining happened with the cars under tension.  When the train then stalled, what would the engineer do with the brakes at that point?  Could he hold the train with just the idependent brakes or would he set the automatic? 

If he set the automatic, I would expect the backup move to begin by releasing the automatic, which would maintain the tension of the stall.  But I suppose the cars ahead of the string line would release and shove back into the string lined cars with buff force. 

Considering that possiblity, it is hard to imagine how those cars can be hanging in mid air like they are. 

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Posted by BaltACD on Sunday, August 28, 2016 7:04 PM

If the train stalled on it's own, the engineer 'should have' felt gravity start to pull the train back down the grade if all brakes were released at the time of the stall.  If the train didn't respond much to gravity that would be an indication that part of the train was off the rails and did not have a normal response to gravity.

Once the engineer decided the train was stalled (whether it was moving or not), upon reducing power the train brake should have been applied with a service application, while the crew (and their superiors) decided what the next actions would be.  Had the decision been to double the grade, the Conductor would begin walking back along the train to determine and/or identify where the cut was going to be made and to apply sufficient hand brakes on the portion of the train that was going to be the 2nd movement so that it would stay where it was.

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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.

 

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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.   

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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.

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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?

 

Sam

 

 


 

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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.

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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 or any other railroad, company, or person.

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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.

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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
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    November, 2013
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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.

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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!

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