Oil Trains Cause Track Defects?

[Euclid]

Norm48327

 

Euclid

1) Oil unit trains do cause more track damage than all other types of trains. 2) Oil unit trains are more prone to derail than all other types of trains.

 

 

Are there statistics to back up those statements?

 

Norm,

If you notice in the paragraph you quoted me from, I had asked for evidence.  That would indeed be the next step.  But my declarations #1 and #2 do not need any more evidence for as far as they go.  Notice that they don’t say how much more tank cars are prone to derail than other types of cars.  That would be a critical piece of information that you are seeking when you ask for statistics.

At the start of this thread, I was originally skeptical of the TSB conclusion that tank cars are more prone to causing track damage, and to being derailed by track defects.  But after having this confirmed by Buslist and Dave Husman, I will accept the TSB conclusion.  So we have the TSB plus two railroaders here who confirm that the unique tank car tank rigidity is the problem, and apparently nobody has solved that problem yet.    

[erikem]

dehusman

 I wouldn't say it "doesn't hold water", but it certainly requires more informationbefore i would agree with it.  and being a skeptic isn't saying that the TSB is wrong, it just means that I haven't seen where they have fully explained or presented their findings (probably because they don't have findings yet.)

That's pretty much my take on the TSB suspicions (hypothesis).

The simplest explanation for the track problems is simply the weight of the trains, in which there is little unique to oil trains versus similarly loaded unit trains hauling other commodities. I would be interested in seeing data or a well worked out mechanism for additional damage from oil trains above and beyond what can be explained by weight alone. Until then, I will choose to treat the TSB suspicions as unproven.

[dehusman]

Euclid

Yes, I agree that we should keep an open mind. But some things are considered to be settled until an open mind finds a reason to change them. So no current proof shall be assumed to be permanent. Two things that are settled about oil trains right at this moment are as follows: 1) Oil unit trains do cause more track damage than all other types of trains. 2) Oil unit trains are more prone to derail than all other types of trains.

Other than you, who determined these issues are settled? 

I don't remember anybody actually presenting anything from any source that documented either of those things.  The TSB suspects those things, they are investigating  those things, but that doesn't make it fact. 

Actually the analysis I did of FRA accident statistics did not appear to support #2.  Nobody has presented any data from any source that documents indicates #1.  The only thing on which we appear to have any concurrence is that unit trains (of all types) are harder on the track than non-unit trains and that tank cars are stiffer than other types of cars.  But it would be a complete stretch of any facts to deduce that from those to points you could say either #1 or #2.

 

[Wizlish]

dehusman

Euclid

Yes, I agree that we should keep an open mind. But some things are considered to be settled until an open mind finds a reason to change them. So no current proof shall be assumed to be permanent. Two things that are settled about oil trains right at this moment are as follows: 1) Oil unit trains do cause more track damage than all other types of trains. 2) Oil unit trains are more prone to derail than all other types of trains.

Other than you, who determined these issues are settled?

Interestingly enough, he cites two influences as important in his reaching that conclusion, and one of them is you.

[Euclid]

dehusman

 

Euclid

Yes, I agree that we should keep an open mind. But some things are considered to be settled until an open mind finds a reason to change them. So no current proof shall be assumed to be permanent. Two things that are settled about oil trains right at this moment are as follows: 1) Oil unit trains do cause more track damage than all other types of trains. 2) Oil unit trains are more prone to derail than all other types of trains.

 

 

 

Other than you, who determined these issues are settled? 

I don't remember anybody actually presenting anything from any source that documented either of those things.  The TSB suspects those things, they are investigating  those things, but that doesn't make it fact. 

Actually the analysis I did of FRA accident statistics did not appear to support #2.  Nobody has presented any data from any source that documents indicates #1.  The only thing on which we appear to have any concurrence is that unit trains (of all types) are harder on the track than non-unit trains and that tank cars are stiffer than other types of cars.  But it would be a complete stretch of any facts to deduce that from those to points you could say either #1 or #2.

 

 

Well I started out earlier in this thread saying that I doubted the TSB point about tank car rigidity compromising suspension, wheel load equalization, etc.  Then yesterday, I was promptly pounced on by Buslist and his expert knowledge, who assured me that I was wrong, and the TSB point is true.  You then came along and backed up Buslist. 

So which way is it?  Did you guys just temporarily side with the TSB so you could jump on my case for criticizing them? 

[wanswheel]

Excerpt from NPR program All Things Considered, Oct. 14, 2013

http://www.npr.org/templates/transcript/transcript.php?storyId=227840021

MANN: Since July, investigators in the U.S. and Canada have focused on a wide range of red flags - from the condition of the tracks, to the staffing level of these big industrial trains, to new evidence that the hazardous chemicals aboard the Lac-Megantic train were mislabeled. But much of the scrutiny has fallen on the type of freight car that erupted that day - those big, sausage-shaped tank cars known in the industry as DOT-111As.

LLOYD BURTON: It's rigid. It's prone to derailment. And when it derails because of the coupling designs, they are prone to puncture.

MANN: Lloyd Burton is a professor at the University of Colorado who studies rail transport of hazardous materials. It turns out, DOT-111As make up two-thirds of the tank cars used in the U.S. and Canada. They're kind of the workhorse of the rail industry. Thousands of them roll through towns and cities across America every day. And Burton says they're carrying more and more volatile crude oil and chemicals produced by North America's booming energy industry.

BURTON: The most dangerous crude, the highest sulfur crude, the most explosive and most flammable materials are now being carried in tank cars. And they're being carried in tank cars that are simply not equal to the task.

[Norm48327]

wanswheel

BURTON: The most dangerous crude, the highest sulfur crude, the most explosive and most flammable materials are now being carried in tank cars. And they're being carried in tank cars that are simply not equal to the task.

Sounds like a program with an agenda: scare people out of their wits. But that's what the media specializes in.

[Randy Stahl]

Sounds like a bunch of crap.

[zugmann]

wanswheel

BURTON: The most dangerous crude, the highest sulfur crude, the most explosive and most flammable materials are now being carried in tank cars.

They tried carrying it in auto racks, but it kept leaking out.

[wanswheel]

If there’s any interest, Burton co-wrote 2011 article, Courting Disaster, excerpt therefrom.

http://www.lawschool.cornell.edu/research/jlpp/upload/burton-egan-final.pdf

Just one month after the Metrolink disaster, Congress enacted the Federal Railroad Safety Improvement Act of 2008 (Railroad Act of 2008), including safety measures such as selective installation of Positive Train Control (PTC) systems and railway crew work hour regulation.Previously, the Bush Administration had opposed such precautionary measures, and the president of the Metrolink commuter rail line had actually testified at congressional hearings a few months prior to the Chatsworth disaster that no statute should mandate such technology, in order to leave railways the flexibility to decide what safety measures are necessary.

Given the haste with which Congress crafted and passed this measure, it represents a classic example of reactive legislation, which will once again lead to reactive regulation. As has happened before, there was an after-the-fact, linear, fault-tree response to this most recent disaster, which is only one example among a depressingly familiar string of disasters. The reactive response was by no means a comprehensive overhaul of the extant fragmented and disjointed regulatory framework. The NTSB achieved the positive train control technology that it had long advocated, but the timeline to implementation was set at 2015, and industry has vigorously opposed the measure.

[Deggesty]

zugmann

 

 

wanswheel

BURTON: The most dangerous crude, the highest sulfur crude, the most explosive and most flammable materials are now being carried in tank cars.

 

 

They tried carrying it in auto racks, but it kept leaking out.

 

ROFL--and now I need somebody to help me up.

What did Mr. Burton think it used to be carried in?

[dehusman]

Wizlish

Interestingly enough, he cites two influences as important in his reaching that conclusion, and one of them is you.

His normal pattern is to misunderstand, misinterpret and then misquote.  That's the only reason I jumped into this part of the fray.  I didn't want people to think his conclusions were my conclusions.  I have never said that oil trains cause more track damage than all other types of trains and do not agree with that statement.  I have never said that oil trains are prone to derail more than all other types of trains and do not agree with that statement.

[Norm48327]

wanswheel

Given the haste with which Congress crafted and passed this measure, it represents a classic example of reactive legislation, which will once again lead to reactive regulation.

Anyone think "Positive Politician Control" would be a good idea?

Edited to say "Politician".

[BaltACD]

Norm48327

wanswheel

Given the haste with which Congress crafted and passed this measure, it represents a classic example of reactive legislation, which will once again lead to reactive regulation.

Anyone think "Positive Politicial Control" would be a good idea?

Term Limits!

[Euclid]

dehusman

 

Wizlish

Interestingly enough, he cites two influences as important in his reaching that conclusion, and one of them is you.

 

 

His normal pattern is to misunderstand, misinterpret and then misquote.  That's the only reason I jumped into this part of the fray.  I didn't want people to think his conclusions were my conclusions.  I have never said that oil trains cause more track damage than all other types of trains and do not agree with that statement.  I have never said that oil trains are prone to derail more than all other types of trains and do not agree with that statement.

 

Dave,

You are right that you made no claims about tank rigidity playing a role in causing tank car derailments.  So I should not have included you as one who did.  I was thinking back to what you have said about it in the past about the subject, but cannot recall that you made the claim even then.  But certainly you did not do so in this thread.

So I will retract what I said after the discussion about this thread answering the question of its title.  I do not think it has been answered here or by the STB.  All we have so far is conjecture.  So I am reverting back to my conclusion of last Thursday when I said this:

Posted by Euclid on Thursday, November 05, 2015 6:44 AM

I doubt that the natural flexibility of a railcar is intended to play any part in the suspension mechanics, springing, or equalization. For practical purposes, a railcar is intended to be rigid.

To me, the TSB comment comes off as stating a fact, but one that is pointless in the context of causing derailments, almost like a smokescreen somehow. It seems like it is reaching for deeper explanations of oil train derailments, just like the LA Times article does (in my opinion).

Dave Husman has mentioned this issue of tank cars being less flexible before on more than one occasion. He said that tank cars are more rigid due to their tubular shape compared to other types of car. However, I don’t recall his conclusion. Maybe he can add something to this.

[HiDesertEd]

Speaking as someone with personal experience as a truck driver hauling liquid loads I can categorically state that , yes, tankers will place more stress on infrastructure.

Any liquid load is subject to "slosh".  Back and forth motion as the tank acelerates or decelerates and side to side force as the angular momentum is changed through turning forces.  It's worse in a tank without any internal baffling but even a baffled tank will go through several "oscillations" before the slosh is completely damped.

When you are dealing with multiple tanks in a row these forces are going to be transmitted from one tank car to another and will take longer to damp out.  A locomotive engineer isn't going to have the same "seat of the pants" feel to this undesired motion as a truck driver so may not be aware of forces building up to a level with potential to cause a derailment, particularly side to side motion.

Any Locomotive Engineers out there with experience hauling long strings of tankers?

[erikem]

Read Randy Stahl's post from November 8 about a page back on this thread. He stated that he didn't feel sloshing from 80 car oil trains, but did feel sloshing with acid trains.

[Wizlish]

Euclid

So I will retract what I said after the discussion about this thread answering the question of its title. I do not think it has been answered here or by the STB. All we have so far is conjecture. So I am reverting back to my conclusion of last Thursday ...

May I gently inquire why you have to make these 'conclusions' so definitively in advance of any actual attempt to figure out from first principles how big the effects would be?

One of the things Mr. Husman and buslist were pointing out -- if I may broadly paraphrase and oversimplify -- is that there are definite physical effects from the increased carbody stiffness - and that "professional" vehicle-motion software modeling programs explicitly include them -- but that these effects alone are unlikely to be producing an increased incidence of real-world derailments.  There is no contradiction between saying 'yes, there are measurable effects from increased torsional stiffness of tank cars' and saying 'these measurable effects will not contribute to a statistically meaningful increase in car derailments'.  And noting this doesn't imply there might, or might not, be situations where the increased-stiffness effects 'tip over' a borderline situation into derailment -- we've simply noted that the explanation the TSB gave in their report does not accord with what other people with distinctive competence in rail/wheel interaction say is happening with heavy unit-train consists.  That does not mean the TSB people are either 'incompetent' or 'wrong' -- it just means more investigation is appropriate.  And that, rather than an urge to 'reach conclusions', is what I think you need to focus on.

As noted before:  While it has not been 'proven' that oil trains have an increased risk of derailment strictly because they are oil trains, the prospective dangers if that is true make it worth examining.  I don't see this as something driven by large amounts of otherwise-mysterious statistical data that no one but 'experts' can parse, in part because there aren't any meaningful systems in place for capturing appropriate data (not 'that'; the word 'data' is implicitly always plural).  If there is in fact a trend in appropriate data that supports an actual causal relationship in oil-train derailments, it will not be 'rocket science' to identify it and describe the physicsthat are involved complete with vectors and magnitudes.  This hasn't been done, in the TSB report for example, and 'extraordinary claims demand extraordinary explanations'.

But in the absence of such a demonstration, you shouldn't feel the urge to 'reach a conclusion' and then, if you revise your opinion, think that you have to reach a different one.  There is no sin in keeping an open mind while the evidence builds and shifts, and in listening to various voices in a debate while forming an opinion.  Those things ought to be part of a good liberal-arts education, and they are in my opinion desirable for a good scientific education as well (not that there is a need for a formal distinction between the two cultures in that respect!)

[dehusman]

Something else that needs to be explained is how sloshing damages the track.

It is relatively simple math to figure out the void size in a tank car.  I ran through the math several posts ago (and to satisfy Schlimm, I graduated from Ridley Township Jr High so I can do geometry and basic math).  The result of that was that the difference in weight transfer was less than the difference between a 263 and 286 car.  It has been explained that only the material filling the void moves and the there is minimal movement in the rest of the body of fluid.

The slosh is NOT an instananeous load, it is a "wave" that builds up over time.  Railroads ran steam engines with way more impact loads from their drivers on weaker track than the average modern main track for a hundred years.

A slosh is in line with the axis of the train (back and forth).  The track structure is designed to accomodate loads moving in line with the track.  That's its job. 

So somebody needs to clearly explain how the sloshing is damaging the track.  If there is no mechanism to damage the track then the whole sloshing thing is moot. Not denying that sloshing occurs, but if it doesn't translate into a force that affects the track enough to cause the components to fail then it doesn't matter from a track damage point.  measuring the vectors and all that rot doesn't mean a thing if there is no clearly explained way that those forces tranlate into track damage.

 

[Euclid]

Wizlish

 

Euclid

So I will retract what I said after the discussion about this thread answering the question of its title. I do not think it has been answered here or by the STB. All we have so far is conjecture. So I am reverting back to my conclusion of last Thursday ...

 

 

May I gently inquire why you have to make these 'conclusions' so definitively in advance of any actual attempt to figure out from first principles how big the effects would be?

Wizlish,

I don’t understand your point.  What conclusion by me are you talking about?  In the quote by me that you have selected, I have basically renounced prior conclusions.  And those were natural conclusions based on what one of the experts (Buslist) here was insisting was true.  In my opinion, he did not make the case.

Regarding the jumping to conclusions, I see no reason why a conclusion needs to be absolutely settled before accepting it.  You can always change your mind of if something later shows the conclusion to be wrong.  In the meantime, you go with what you have.  A choice to wait for 100% proof before reaching a conclusion implies that all conclusions should be valid forever once they are made.  That indeed would not be an open minded attitude.

We have talked about two different possible mechanisms for causing tank trains to derail more easily and/or cause track damage.  One is load sloshing and its resulting dynamic load.  The other is a relative deficiency of tank car suspension and wheel load equalization caused by tank cars being less torsionally flexible than other types of cars.   

The latter assumes that the natural flexibility plays a role in the suspension functions, and being that such flexibility is relatively lacking in tank cars; it means that suspension functions are compromised in tank cars.  This assumes that the lack of flexibility cannot be compensated for in the design of the truck suspension for tank cars.  I doubt that these assumptions are accurate.  I also doubt that these issues are unresolved.  They are part of the facts of suspension design and should be readily verifiable by anyone familiar with the state of the art in suspension design. 

The fact that design modeling programs account for car body flexibility does not prove that the lower flexibility of tank cars forces them to have less than adequate suspension performance compared to other types of cars.  

[tree68]

While I have no doubt that there could be movement of product in a tank car (no matter what the product), I have a real problem with use of the term "slosh."

verb

 

1. 1.

   (of liquid in a container) move irregularly with a splashing sound.

   "water in the boat sloshed around under our feet"

   synonyms:

   spill, slop, splash, flow, overflow "beer sloshed over the side of the glass"

   •  

      
   •  

      

noun

 

1. 1.

   an act or sound of splashing.

   "the distant slosh of the washing machine in the basement"

To me, a slosh is created by a sudden or a repetitive movement.  Railroads are not about sudden movement, short of a catastrophe.  Acceleration and deceleration are generally gradual, and virtually non-existant at speed.

I could see some sloshing on jointed rail, such as has been discussed with grain hoppers and harmonic oscillation.  But that usually occurs within a fairly narrow range of speeds (our passenger cars don't like 17 MPH +/-), and is from side to side, not fore and aft.

I would opine that the track profile necessary to set the product in a tank car rolling fore and aft with any significance is going to be rare.

And I would still question why this problem hasn't surfaced with alcohol cars, which have been running far longer than crude.

 

[Randy Stahl]

This morning I was doing a runby of a 90 car alcohol train through the yard at 10 mph, the train stopped in a normal manner directly in front of me. I could visually see the cars moving themselves back and forth with all the brakes set. I am certain, the alcohol does move around inside.

I actually did the rollby and observation because of this thread ...

 

Randy

[tree68]

Randy Stahl

I am certain, the alcohol does move around inside.

Which begs the question:  Why all the "problems" with oil trains but not with alcohol trains, when it appears they may behave very much the same?

Or have we missed something with the alcohol trains?

Thanks for the observation, Randy.

[dehusman]

Ethanol trains have burned before back when they were new.  Haven't done the research to see if they had as many accidents.  Don't know if we haven't heard much about them because there aren't the accidents, they are old news or alcohol burns with a really blue flame which is hard to see, so they make lousy TV.

 

[BaltACD]

dehusman

Ethanol trains have burned before back when they were new.  Haven't done the research to see if they had as many accidents.  Don't know if we haven't heard much about them because there aren't the accidents, they are old news or alcohol burns with a really blue flame which is hard to see, so they make lousy TV.

And I haven't heard of Ethanol trains 'exploding' - just catching on fire when the circumstance are right.

[tree68]

dehusman

Don't know if we haven't heard much about them because there aren't the accidents, they are old news or alcohol burns with a really blue flame which is hard to see, so they make lousy TV.

Or....  Ethanol "reduces" our dependence on fossil fuels, while crude is the poster child for our use thereof.  Yep - that's a political statement.  Can't be pointing out that ethanol is potentially as much of a problem as crude, can we?

[schlimm]

tree68

 

 

dehusman

Don't know if we haven't heard much about them because there aren't the accidents, they are old news or alcohol burns with a really blue flame which is hard to see, so they make lousy TV.

 

 

Or....  Ethanol "reduces" our dependence on fossil fuels, while crude is the poster child for our use thereof.  Yep - that's a political statement.  Can't be pointing out that ethanol is potentially as much of a problem as crude, can we?

 

1. There was a derailment of a CN ethanol train by Rockford a few years ago due to heavy rains undercutting a raised embarkment.  A woman got trapped in her car (near a crossing I recall) and burned to death.

2. Many environmentalists are opposed to ethanol use since it appears to require more energy to produce than it provides.

[tree68]

I'm aware of the Rockford incident.  And I've heard that about ethanol.  

But after pushing ethanol the way it was pushed, it would look bad to point out that it could be a problem, too...

[schlimm]

Most of the pushing came from producers, corporations, like ADM and Cargill, and their politicians in corn-growing states, not from real environmentalists. There were many inaccuracies put forth in studies (sponsored by ADM and Cargill, in many cases) concerning net fuel use to produce.   The slogans about "clean fuel made in America" were just that.

[Norm48327]

schlimm

Most of the pushing came from producers, corporations, like ADM and Cargill, and their politicians in corn-growing states, not from real environmentalists. There were many inaccuracies put forth in studies (sponsored by ADM and Cargill, in many cases) concerning net fuel use to produce.   The slogans about "clean fuel made in America" were just that.

 

Precisely.Just follow the politics and the money. Oh, and ethanol doesn't help the price of food either.