Oil Train

[Euclid]

Don,

I conclude that the relationship of ECP brakes to sensors is that ECP brakes offer the communication line that facilitates the addition of sensors for a variety of purposes by providing the means of information transmission of the sensors.  But it does indeed raise the question of what sensors are needed and how they will work.  I do not have an exact concept for derailment sensors, but expect that they could be developed.  I have found other references to them, but no details of how they work. 

I generally think they could detect a derailment by sensing vibration and alignment of the cars.  Possibly the detection of truck frame elevation in relation to the rail could be included.  Maybe this has all been worked out to produce a practical derailment sensor, but I am not aware of it.  But it has to be reliable and able to discriminate those other defects that you mentioned.  I am thinking that because a derailment is so chaotic and disruptive, it ought to be fairly easy to detect with the proper sensing elements.

You mentioned the question of how ECP brakes emergency activation compares with that of conventional pneumatic brakes.  I have been wondering about that too.  I assume that if the ECP communication line breaks for any reason, it would set the brakes just like an air hose breaking or parting with conventional air brakes.  But I don’t recall ever seeing that explained.  It is an interesting question because of the differing ways that the two systems communicate a brake application.

[zugmann]

oltmannd

What is this and how would it function? How could it tell a derailment from truck hunting, rough crossing, slack action, etc?

 

If memory serves me corect, I think I read that some steam locomotives had derailment sensors.  Basically looked like load/empty sensors and were mounted on the tender.  If the body of the tender came too far away from the trucks, it dumped the brakepipe. 

[Euclid]

Derailment sensors could tell ECP brakes to suspend their default operation, and revert to a special emergency protocol. So even if an ECP equipped train separated during a derailment, both halves could continue to adjust their braking effort in response to a central control, and do so independently of each other. 

However, this retention of braking control for both halves after separation requires some other way to communicate that message after the train separates.  This is because when the train separates, the wire breaks.  So any further communication between the two separated sets of cars has to be wireless.

ECP is not just an advancement to be compared with conventional brakes.   It also opens the door to a lot of other advancements in safety, and efficiency.  It certainly has its cost, and nobody wants to bear that.  So people line up on both sides of the issue.  The ECP side brags up the benefits, and the bill-paying side says the benefits are small and not worth it. Everybody is weighing those pros and cons as the regulators get ready to impose their solution.           

[Wizlish]

zugmann

If memory serves me correct, I think I read that some steam locomotives had derailment sensors. Basically looked like load/empty sensors and were mounted on the tender. If the body of the tender came too far away from the trucks, it dumped the brakepipe.

See if you can find a reference for tender sensors.

There is, of course, a more famous derailment detector, in a more sensible place for a steam locomotive to have one: the "Wright's Little Watchman" as, for example, found on NKP 765.  Too much relative motion between the leading truck frame and the locomotive, and the air goes into emergency until the device is reset by reaching under the pilot beam.

See the article in this .pdf from the RR Museum of Pennsylvania for more on the device.

[zugmann]

Tender - trailing truck... close enough.

 

That was what I was thinking of.  

 

 

[jeffhergert]

oltmannd

ECP braking just replaces the "brakes on" signal, that now runs at nearly the speed of sound down the trainline, with one that operates at near speed of light.

All the other fancy stuff that could be done, like load/empty variable braking, car health monitoring, ride monitoring, bad journal bearing detection, are not part of basic ECP.

ECP provides smoother braking because brake actuation can be faster (no need for damping that keeps pneumatic control valves stable) and will apply simultaneously on every car.

You get faster recharge because the trainline just provides one fucntion - fill the reservoirs - and can be run "wide open".

You get much shorter braking distances at low speed, but not very much improvment at higher speeds.

One thing I don't know - how will an ECP train know to go into emergency at a break-in-two?  Loss of comm?

 

I think the loss of air pressure in the train line (even though it is now a "supply" line in ECP)if it parts will still cause the brakes to go into emergency.

Jeff

 

[Paul_D_North_Jr]

oltmannd

[snipped - PDN] . . . You get faster recharge because the trainline just provides one fucntion - fill the reservoirs - and can be run "wide open". . . .

Don - Not to split hairs but:

I thought another advantage/ function of ECP braking was the capability of 'graduated release'.  I.e., unlike the 'regular' air brake trainline - which has to be fully released before making another 'lesser' application (or recharging the reservoirs) - ECP can 'hold' (retain) the pressure in the brake cylinders while simultaneously signalling to the valve to allow the high air pressure trainline to recharge the reservoirs. 

On this point (and others), see:

http://www.railway-technical.com/brake3.shtml - "Benefits", near the bottom

http://www.nyab.com/media/banner/documents/downloadsservices/products_1/ep60_1/ep60.pdf 

http://www.uic.org/cdrom/2001/wcrr2001/pdf/sessions/1_6/465.pdf - middle of pg. 2

http://www.progressiverailroading.com/mechanical/article/Cost-constraints-economic-conditions-to-delay-widespread-electronically-controlled-pneumatic-brake-implementation--22315 

Slides 3 and 5 of this 2007 NS presentation: https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&cad=rja&uact=8&ved=0CDEQFjAD&url=https%3A%2F%2Frsac.fra.dot.gov%2Fdocument.php%3Ftype%3Dmeeting%26date%3D20071025%26name%3DNS%2BECP%2BBrake%2BImplementation-10-25-07.pdf&ei=DTEfVfSKLYqpsAXB64PYCA&usg=AFQjCNGhZ4DPKA_0c9txIOO4uJy_01FrSg&sig2=L38iqyhTbFtXs45wZeO34w&bvm=bv.89947451,d.eXY 

http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=5&cad=rja&uact=8&ved=0CDcQFjAE&url=http%3A%2F%2Fwww.fra.dot.gov%2FElib%2FDocument%2F1602&ei=DTEfVfSKLYqpsAXB64PYCA&usg=AFQjCNECHFaVGxvAqxcDEEUsn2faEc32RQ&sig2=FJbWII5hvHD8SZe4HZwa2w&bvm=bv.89947451,d.eXY 

- Paul North. 

[MidlandMike]

Euclid

... 

However, this retention of braking control for both halves after separation requires some other way to communicate that message after the train separates.  This is because when the train separates, the wire breaks.  So any further communication between the two separated sets of cars has to be wireless.

... 

For the wireless to work, wouldn't each car would have to be in communication with a tower or router?  I suppose it could piggyback on the PTC system, however, they have had problems acquiring enough bandwidth for just for the engines.  Now it seems you have complicated the problem a hundred-fold.

[dehusman]

MidlandMike

  Now it seems you have complicated the problem a hundred-fold.

You have found the essence of Euclid.

[BaltACD]

dehusman

MidlandMike

  Now it seems you have complicated the problem a hundred-fold.

 

 

 

You have found the essence of Euclid.

 

Winner! Winner!  Chicken Dinner!

[Euclid]

I am eliminating the following two features of this differential braking concept:

1)    Wireless control.

2)    Adjusting braking according to train location.

 

These items are not essential, and either or both can be developed later if there is a need for them. 

 

Most of the advantage of the differential braking that I suggest will apply before the train separates.  That advantage will then continue to help prevent a separation.  In certain cases where separation does occur, this system will help prevent the cars behind the derailment form colliding with the cars ahead of the derailment.  This would be in cases where the trailing truck of a car derails, and separation occurs at the joint behind it, leaving all the cars behind the derailed truck still on the rails. 

Regardless of separation, the differential braking would begin the instant the first wheels derail.  That is the instant that ECP will begin the differential braking by a signal through the wire.  At any point, thereafter, the wire might break.

Therefore, any modulation of braking after the derailment is detected will have to be programed into the logic of each car as a predetermined response.  So the derailment sensors tell the system to begin the instant a derailment happens, and from there on, the system is on its own without any further commands through the wire.  

Research would be needed to learn whether the system would ever need any modulation.  If it does, it might be programed in as part of every response.  Or perhaps, modulation might be advantageous in relation to an external factor such as train speed.  If so, speed could be sensed on every car and communicated to the ECP control even if the wire is broken at the point of derailment. 

Another point to consider, however, is that even with the wire being broken, it still offers a continuous line of control on either side of the break.  The difference in brake force called for in this system will come from reducing the brake force on the cars ahead of the derailment.  So there is still the possibility of modulating the brakes on these cars through the wire from the head end even though the wire is broken at the point of derailment.             

[dehusman]

Euclid

 So the derailment sensors tell the system to begin the instant a derailment happens, and from there on, the system is on its own without any further commands through the wire.  

Not the instant it happens, braking will begin the instant its detected.  It is detected whenever the conditions exceed whatever limits you have set up to indicate there is a derailment.

There are three braking rates, the head end, the rear end and the derailed cars.  The fastest deceleratio rate is that of the derailed cars.  They will stop faster than the rear of the train.  Once the cars leave the rail, you lose contrl of their direction and braking rate.  They are unguided.

 

Another point to consider, however, is that even with the wire being broken, it still offers a continuous line of control on either side of the break.  The difference in brake force called for in this system will come from reducing the brake force on the cars ahead of the derailment. 

What advantage is that?  The rear of the train isn't going to run into the head end, its going to hit the pile of cars with no track under it that is between the head end and the rear end.

 

[Euclid]

Dave,

To your first point:

The point of the derailments sensor is to detect a derailment the instant it happens.  When it does that, it will begin the braking.  So, for practical purposes, the braking begins the instant the derailment happens, even if it does technically lag for a fraction of a second.

To your second point about the three braking rates:

If the derailed cars stay together, they will be subject to the kinetic energy of the cars ahead of the derailment pulling on them.  I agree that once enough cars are derailed, their resistance will exceed the braking resistance of the cars ahead.  Once that happens, the tension between the derailing cars and the cars ahead of them will become so great that it will part the train somewhere in that range of maximum tension.  However, it is not a forgone conclusion that enough cars will derail to meet that threshold.  And even if it does, there still may be enough time beforehand to dissipate a large amount of the kinetic energy that will feed into the derailment, thus resulting in fewer cars derailed than without this system     

To your third point:

The cars behind the derailment could run into the cars ahead of it if the cars behind the derailment are all on the rail; and if the derailed cars are still coupled to the cars on the rail ahead and being dragged by those cars ahead still on the rail. 

But, as I mentioned, the main point of this system is to stop the train or reduce its speed before the train parts, and also to help prevent it from parting.     

The main point I was making about the wire is that even if it breaks, it can still function on either side of that break.  So, in that sense, it differs from the control attributes of the train line in conventional air brakes.  But as I said, I see little need for any modulation of the brake forces that would need to be communicated to the cars through the wire.   

[BaltACD]

If if's and but's were candy and nuts, what a wonderful world it would be.

Inertia and Momentum decree what happens after a wheel leaves the rail - no matter how quickly and uniformly the brakes are applied.

 

[tdmidget]

Bucky, why is it that your solution to every problem seems to be the addition of nonexistant electronic whizbang doodads to the one of the the most reliable , simplest, and efficient machines, ( railcar) in history? And applied in areas where it is impossible to even keep a coat of paint? None of your ideas exist, or are well thought out, or can be practically implemented even if they did exist. Time to come back to reality.

Maybe take a look at your ideas on the the Nevada collision of the Southwest Chief to see how in touch with reality your ideas are.

[tree68]

Euclid

But, as I mentioned, the main point of this system is to stop the train or reduce its speed before the train parts, and also to help prevent it from parting.     

You need to go back and watch that video I posted the link to a bit ago.  Watch it very closely.  Several times, even.   It gives lie to many of the things you presume will prevent derailments, etc.

[Euclid]

What video is that?  I don't recall it and don't readily find it.

[Wizlish]

Here is the reference (from March 24 at 10:50 am):

tree68

Here's your derailment dynamics right here:

https://www.youtube.com/watch?v=a-smEEHYdGQ

This is the well known video of the train hit by a tornado.

I don't think this is particularly demonstrative of the kinetics of most derailments.  Here the cars were bodily toppled over (still 'railed' to the last!) almost incidentally taking the adjacent ends of the train off the rails as they went.  One might argue that if the head end had not stopped short in emergency, the following part of the train would have come to a stop by itself once the parted-hose emergency braking had taken hold. 

Euclid's system is assuming that the early moments of a derailment don't result in a catastrophic motion of the cars, either in massive yawing or massive deceleration, and that if through nothing else but momentum the car continues in a straight line, coupled at both ends, with flange contact with ties and ballast continuing to make the truck frame track approximately straight.  The film of the Army tests 'optimizing' sabotage during WWII establishes how difficult it can be to produce an actual derailment even with large pieces of the rail missing. 

It's that scenario -- one or more cars with wheels now bumping along the ties rather than smoothly on the rails -- that the differential-braking system is intended to address.  I would be tempted to look into methods for assuring the integrity of trucks subjected to this -- locking the wheelset bearings to the sideframes, for example, or restricting the yaw rotation rate of the truck relative to the underframe, or providing some default detented centering of the truck frame relative to the underframe if a derailment is detected -- as things that might be secondarily beneficial.

I also think that differential-braking apparatus, if designed correctly, would help with other situations, notably the tendency to 'snatch a knuckle' during emergency braking.  If braking effort is so proportioned in a given consist that the instantaneous load at any coupler is kept under control, but overall also modulated to produce high retarding force up to the point of wheelslide, you still have high 'enough' braking effort to produce a minimum-distance stop, but have virtually eliminated derailment or separation problems from things like dynamiters... without necessarily going to the expense of two-pipe electropneumatic braking.

[Euclid]

tree68

 

Euclid

But, as I mentioned, the main point of this system is to stop the train or reduce its speed before the train parts, and also to help prevent it from parting.     

 

You need to go back and watch that video I posted the link to a bit ago.  Watch it very closely.  Several times, even.   It gives lie to many of the things you presume will prevent derailments, etc.

Oh, I did not know that you posted it.  I saw it posted by BaltACD.  But in any case, I am extremely familiar with that tornado derailment.  I have watched it at least 50 times, and start/stopped it at least 200 times.  I have turned it inside out in order to learn exactly what was happening.  So how does it give lie to my ideas about what will prevent derailments?

 

[Euclid]

BaltACD

Inertia and Momentum decree what happens after a wheel leaves the rail - no matter how quickly and uniformly the brakes are applied.

I am not talking about doing anything directly to the derailed cars for the purpose of influencing them.  I am talking about doing things to the cars still on the rails in order to get them to influence the derailed cars.   

As the first wheel leaves the rail, it is at the decree of inertia and momentum, as you say, but there are maybe 100 cars with their 800 wheels still on the rails that are not at that whim.  Those cars and their braking can surely affect what happens after the first wheel leaves the rail. They can exert influence over the train to keep it from parting at the derailment, even if the number of derailed wheels grows.  So the derailed cars will not necessarily be entirely at the decree of inertia and momentum if staying coupled helps keep them aligned rather than jackknifing.    

Just stopping the train quicker will reduce the number of cars going into the pileup if one develops.   

[Euclid]

I assume that Larry is referring to the chaos in the tornado derailment as being an insurmountable obstacle to my ideas.  In the tornado video, the tornado forced several cars off of the track almost simultaneously.  The first car to derail was back maybe 4-6 cars behind the engine.  You can hear the train dynamite when that first car derails.  Then cars followed it off in both directions from there all the way to the engine, and all the way back to the tank car.

I agree that, even without the broad force of a tornado, a derailment can instantly lead to a massive, chaotic pileup.  Even though there is value in preventing the parting for as long as possible, it is possible for a derailment to begin with a drawbar being pulled out and derailing the train, for example.  In that case, the train parts even before the derailment begins.  Certainly it will instantly begin to jackknife as soon as the derailment begins.  It would be impossible to shove a derailed car down the track and expect it to run straight.

But there are many derailments that immediately lead to dragging the derailed car for considerable distance without tearing up the track enough to derail the following cars.  That status can persist for a while until it is perturbed enough to start tearing up the track enough to derail more cars; or the first derailed car can suddenly break up the derailed truck and pass pieces back under following cars and derail them.

But while the car is being dragged, there is a window of opportunity to stop the train before it derails more cars or progresses to a pileup.       

Certainly there can be instant, extreme chaos starting the instant a derailment begins and the system I propose may not help at all in such cases.  It is not intended to be an infallible way to prevent all train wrecks, just like air bags are not infallible in preventing all injuries or death.      

[Norm48327]

And the "One Note Samba" goes on and on. The same never ending song.

[BaltACD]

Euclid

 

BaltACD

Inertia and Momentum decree what happens after a wheel leaves the rail - no matter how quickly and uniformly the brakes are applied.

 

 

I am not talking about doing anything directly to the derailed cars for the purpose of influencing them.  I am talking about doing things to the cars still on the rails in order to get them to influence the derailed cars.   

 

As the first wheel leaves the rail, it is at the decree of inertia and momentum, as you say, but there are maybe 100 cars with their 800 wheels still on the rails that are not at that whim.  Those cars and their braking can surely affect what happens after the first wheel leaves the rail. They can exert influence over the train to keep it from parting at the derailment, even if the number of derailed wheels grows.  So the derailed cars will not necessarily be entirely at the decree of inertia and momentum if staying coupled helps keep them aligned rather than jackknifing.    

Just stopping the train quicker will reduce the number of cars going into the pileup if one develops.   

 

I'm not talking about the derailed cars either - I am talking about the rest of the train - both fore and aft of the derailed cars.

Please exit your dream world of train dynamics.

[Euclid]

Here is a highly instructive video that shows that total chaos does not always commence the instant the first wheel leaves the rail.  Note the large boxcar that is methodically tipping the rail over onto its side as it goes along; and all the following cars are happily running on the side of the rail between the base and the ball.  Nineteen cars derailed and none tipped over or jackknifed:

https://www.youtube.com/watch?v=fBYqdmsxeCQ

[Wizlish]

Illustrations of the kind of derailment where controlled differential braking might apply:

In my opinion, slack running in is a major cause of these types of derailment progressing to the point that major fouling of adjacent tracks, or 'accordion'-style piling up as drawgear pulls cars laterally, or sequential rollover of cars through torsion.  So detecting a derailed car and controlling the braking rate of both 'ends' in a way that controls slack action, as early as possible after the derailment, should be of benefit. 

I think there should be enough intelligence in the system to recognize when there is a 'sequential' derailment (say, following a picked switch or displaced rail) and do some predictive modulation of the brakes, either by car or by block of cars.

Euclid, there is a valid point about 'instant' detection of derailments.  I do not think this is practical; you'll have to distinguish actual derailment from rough track and the usual kinds of shock, with a robust and cost-effective device.  There are plenty of approaches that would work in theory and on test, like adaptation of machine vision to watch wheel-rail interaction, that are not likely to prove effective in long-term service with typical maintenance even on dedicated 'safety' consists.

[Euclid]

Wizlish,

I have been looking at that second video that you posted.  It too is very instructive.  Notice that the derailed car has its trailing truck turned completely crosswise to the direction of travel, and its wheels are plowing up the ballast.  Notice too that there is a wheelset that has been released from the lead truck, then snagged by the first hopper bin, and is plowing up ballast.  This would indicate that the lead truck is partially destroyed from the derailment.  Yet, even with one crosswise truck plowing ballast, and one partially destroyed truck with one of its detached wheelsets plowing ballast; the car is kept in line by the cars on either side of it. 

Notice what happens when the derailed car hits the grade crossing as it is pulling away from the photographer.  The crossing abruptly straightens the car back up to vertical, but it also snags the derailed truck. 

As this happens, notice the wheelset that pops out from under the car and rolls over to the adjacent track to the right.  Then the car continues running in line and completely upright with a missing wheelset.  All of this is made possible by the fact that the train is being pulled with the slack stretched.  The stretched condition has great influence to keep the derailed car in line.

https://www.youtube.com/watch?v=8YKZFHsnvoA

[Paul_D_North_Jr]

Wizlish, thanks so much for posting that Cresson video. [EDIT: Just 3-1/2 months ago, Dec. 27, 2014 - https://www.youtube.com/watch?v=fBYqdmsxeCQ ]   It belongs in its own thread (and I was there just 2 weeks ago).  More to the point, I've seen the result of that kind of derailment: "All it did was turn over 1 rail.  Oh, by the way - the rail is 4,000 ft. long !"  And it trumps the double-flanged wheel April Fool's Day thread, too - what's really needed is a U-shaped rail for the wheels to run in as in the video - note that everything stayed together and in line.  The opposite side wheel might have even stayed up on its rail, too.  (Wonder what finally got them stopped, and how much of the interlocking got torn up by then . .  .)

Back in the 1960's, there was a heckuva explosion 9actually several) in the SP yard at Roseville, CA - might have killed a couple people, but it certainly destroyed a good portion of the yard.  The cause was eventually attributed to a Navy bomb (bound for Vietnam) falling through the weak floor of a boxcar and rubbing against the wheel until the heat from the friction led to the explosion.  See:

http://en.wikipedia.org/wiki/Roseville,_California#Notable_events  

http://www.trainorders.com/discussion/read.php?1,185297 

From http://www.insensitivemunitions.org/history/railroad-train-fires-and-munition-explosions/ [emphasis added - PDN]: "Fortunately, a person recording train sounds in the mountains outside of Roseville, CA had seen the train. He testified that he had seen a fire in the floor over the wheel of one of the boxcars in that train some six hours before the first explosion occurred in Roseville."

As a result of that and some other high-profile derailments, there was an attempt by the Navy Ordnance people to develop several kinds of sensors to detect derailments, "hot boxes", and other mishaps before they got too far out of control and caused other bomb shipments to explode; all of this was reported in Trains or Railway Age at the time.  I specifically recall that the hot box detector would be mounted in or on the truck frame.  Whether any of this was ever fielded for tests and then made practical (even if not widely adopted), I do not know.

- Paul North.  

[Paul_D_North_Jr]

At least one company has developed a derailment detector - in response to 3 tank car derailments in Switzerland ! (in the 1990's)

See slide 2 of 18 of this presentation from October 2014 (1.40 MB electronic file size):

http://www.otif.org/fileadmin/user_upload/otif_verlinkte_files/05_gef_guet/03_AG-Entgleisungsdetektion/2014_10/CE_GTDD_2014-A_Annex_V_Presentation_Knorr-Bremse_E.pdf 

http://www.knorr-bremse.de/en/railvehicles/products/trainsafety/edt101.jsp 

http://www.knorr-bremse.com/media/documents/railvehicles/en/p_1216_en_04_edt101.pdf (4 pages, 440 KB electronic file size)

- Paul North. 

[BaltACD]

Paul_D_North_Jr

As a result of that and some other high-profile derailments, there was an attempt by the Navy Ordnance people to develop several kinds of sensors to detect derailments, "hot boxes", and other mishaps before they got too far out of control and caused other bomb shipments to explode; all of this was reported in Trains or Railway Age at the time.  I specifically recall that the hot box detector would be mounted in or on the truck frame.  Whether any of this was ever fielded for tests and then made practical (even if not widely adopted), I do not know.

- Paul North.  

 

I believe Amtrak uses on board Hot Box detection equipment.  At least on my carrier, if a Amtrak car activates 2 Hot Box Detectors, the Amtrak car can continue in the train if the On Board Detector indicates no defect.  With freight cars rule require a car activating 2 HBD's to be set out, PERIOD, even if the journal shows as being of 'normal' temperature.

[Euclid]

Paul,

Thanks for posting that reference to the Swiss derailment detector.  It is interesting to note that their device is all pneumatic for application to cars with conventional air brakes.

They make the same point that I have been making here to the skeptics.  That is that every derailment does not instantly lead to a chaotic pileup as has been suggested by the reference to the Tornado derailment on the U.P. posted earlier.  The Swiss report says this:

“A derailment does normally not lead to an immediate as the car continues to run until an “obstacle” like a switch comes in the way.”

 

As the two above videos show, in some derailments, cars can be dragged in line for long distances without ever progressing to chaotic jackknifing.  And this is not dependent on relatively slow speed typical of the two videos.  I have seen a case where a car was dragged 4 ½ miles at about 50 mph, breaking every tie, creasing every tie plate, mashing spikes, and continuously throwing ballast 20 feet from the track.  It was a burned off journal, and the car stayed in line all the way. 

Another identical incident occurred at the same location, but the car finally hit a crossing diamond, and tipped over, thus parting the train.  I have seen other similar dragging instances.

But the point is that these incidents could have led to a massive, destructive pileup with all the destruction and possible death or injury that is implied.  A derailment sensor would have had plenty of time to prevent that outcome.