Concept for a Safe Oil Train

[Murphy Siding]

CSSHEGEWISCH

Euclid seems to be ignoring one issue in his proposal, the law of conservation of energy:  Energy can neither be created nor destroyed.  A moving freight train contains lots of kinetic energy, which has to be converted to another form of energy when the train stops.  In a normal brake application, the kinetic energy is converted into heat energy by the brakes and is dissipated into the atmosphere.  In a derailment, that energy is going to have to go somewhere much more quickly, a lot of it is absorbed in the accordioning of a string of freight cars before they come to rest.  The brake shoes and wheels would have to absorb a lot of energy very quickly to prevent this from happening.

  Yes, but....The kinetic energy of 10,000 trailing tons of train would be transferred to the brake shoes.  Because this would happen in such a short period of time, on all the brakes on every car, all at once, the brakes would become so hot so fast, that they would naturally weld themselves and the wheels to the rails in a few seconds.

      A 100 car train plus 3 locomotives equals about about 836 wheels being welded to the rails in the wink of an eye.  Logically, that in itself should stop the train cold in it's tracks.

[daveklepper]

Nope!    Even with lots of sand, the cars with  non-rotating wheels will SLIDE!!!!   Every active railroader knows that.  And you know whar?  The braking force GOES DOWN as the wheels start sliding! Or do you propose two arc welder's attached to every freightcar truck?

What you want is magnetic track brakes.  Allows PCC streetcars and modern light railcars to stop as quickly as rubber-tired personal automobiles.  Used by West Penn Interurban cars in 1912.   Highly impractical for interchange freightcars, but might be adopted along with electric control brakes for new fixed-consist unit trains.  Was looking over the shoulder of a Jerusalem Light Rail operator accelerating south from a stop light north of Damascus Gate station when a tourist on a bicycle (tourists recognized in Jerusalem by their carrying a water bottle as if they are in the middle of the desert) swerved directly in front of us, about 12 - 15 feet in front.   We went from 12mph to stop in about 5 feet, and I was pleasantly suprised to see that no standees that I could see landed on the floor.   Lots of people grabbed the nearest handhold, including some seated passengers.

[Euclid]

CSSHEGEWISCH

Euclid seems to be ignoring one issue in his proposal, the law of conservation of energy:  Energy can neither be created nor destroyed.  A moving freight train contains lots of kinetic energy, which has to be converted to another form of energy when the train stops.  In a normal brake application, the kinetic energy is converted into heat energy by the brakes and is dissipated into the atmosphere.  In a derailment, that energy is going to have to go somewhere much more quickly, a lot of it is absorbed in the accordioning of a string of freight cars before they come to rest.  The brake shoes and wheels would have to absorb a lot of energy very quickly to prevent this from happening.

I am not saying that my idea is stop the train abruptly at the onset of a derailment in order to prevent it from piling up cars.  The idea is to keep the train stretched as much as possible during the derailment to prevent the accordion process as much as possible.  The train will still take its normal distance to stop.  If several cars are on the ground, they will add some stopping power, so the train will stop somewhat quicker than usual.    

For an oil train, the accordion process is sure to rupture tank cars.  Any rupture will spill oil.  Any spillage will ignite.  Once that happens the other un-ruptured tank cars are stacked up just like a bed of logs in a fireplace; all ready and eager to be ignited by the ruptured and burning car or cars. 

[Euclid]

Norm48327

Assuming the first car derails, and you have 10,000 tons trailing that car, how much energy do you think it would take to stop the remaining cars without decimating the first car? Train brakes can't possibly supply the necessary force.

Norm,

It will take time for the brakes to stop the 10,000 tons trailing the derailed car, but the force of those trailing cars will not decimate the derailed car unless that car is blocked from forward movement. 

It won’t be blocked from forward movement unless it becomes a part of a pileup of cars that have stopped moving as they jackknifed into the pile. 

If all those cars could be kept moving, they would not pile up, and the 10,000 tons of trailing cars could just keep moving forward with not much interference.  The way you keep those derailed cars moving is to keep them coupled and hold off on braking the cars ahead of them.  

[Norm48327]

Nice job of sidestepping the question.

[tree68]

All of Bucky's ideas here are predicated on a simple wheels-off-the-rail derailment.  Any catastrophic failure (wheels, trucks, track) or outside force (ND) negates the whole thing.  The car involved will go from whatever speed to zero MPH within a few feet, while the rest of the 10,000 tons continues at speed for several seconds, even with an emergency application of the brakes.

I know from experience that it takes greater than a train length to stop a four car passenger train from 30 MPH.

At 30 MPH (a great reduced speed for that hazmat train), the train is travelling at 44FPS, or roughly 2/3 car per second.  Three seconds is two cars with no place to go, because the car in front of them has stopped dead.

And I still haven't figured out how this "stretched" thing works if the entire train is in buff (ie, in dynamics).

[Euclid]

tree68

The car involved will go from whatever speed to zero MPH within a few feet, ...

That is not true.  I recall seeing a car on the Milwaukee that derailed from a burned off axle and ran on the ground for 4 ½ miles undetected.  It broke the end off of every tie, clipped the corner off of every angle bar, and creased every tie plate for 4 ½ miles.  That kind of thing happens all the time.  The only way a car is going to dig in and stop in a few feet is if it is moving very slow, and is on its own with no cars on the rails behind it. 

[tree68]

Euclid

That is may not be true.

Fixed it for ya.

[Euclid]

Norm,

I had no intention of sidestepping your question.  The 10,000 tons will simply follow the first car (the derailed car, if that is what you mean) until the brakes and general friction stops the train.  Your question seems to indicate that you interpret me to be claiming that the entire trailing part of the train will stop on a dime to avoid crushing into cars ahead.  That is not what I am proposing.    

[dehusman]

He hasn't tumbled to the fact that everybody who has had any experience with real derailments or trains see major flaws in the premise (and physics) of the plan.

[Euclid]

Dave,

You are free to see all the flaws you want.  Do you think that everybody who has experience with derailments and trains agrees on everything? 

[daveklepper]

Euclid, how about electrically applied and release brake control, and magnetic track brakes, for all special purpose unit trains?

[Euclid]

dehusman

Euclid

There won’t be multiple dynamiters, as you suggest, because the system will not dynamite the brakes in the traditional sense of a rapid loss of train line pressure triggering a pneumatic chain reaction of emergency braking.  There will be no brake actuation controlled by brake-pipe reduction since that is eliminated by the ECP approach.  The brake pipe simply charges the car reservoirs.  The ECP system does apply brakes on all cars simultaneously, as you mention.  That is the beauty of ECP electronic control by wire versus the conventional air brake control by changes in the train line pressure. 

So if the train breaks in two (but doesn't derail) the brakes don't set up?

 

There's a safety feature.

 

Yes, that is a very good point.  The break-in-two application is a safety feature of conventional air brakes.  The concept I am proposing is an added feature to the ECP brake system that has been developed so far.  The only way my feature takes action is if one of the sensors detects a derailment.  If that happens, my feature kicks in and overrides the normal full train emergency braking feature.  If the train breaks in two, the normal full-train brake application will occur.    

But when the derailment sensor detects a derailment, it starts the new system that I am proposing.  That system replaces the normal emergency response with a better response.  It does eliminate a safety feature, but it replaces it with a better safety feature.  It only does this once a derailment is detected. 

That improved safety feature would be to split the braking control of the cars ahead of the derailment from the braking control of the cars behind the derailment.  That way, it could control the two braking ranges independently.  Mainly, it would brake the cars behind the derailment with more force than the cars ahead of the derailment.  As I mentioned, the decision making in this specialized response would be fully automatic according to a program and a processor evaluating many different variables to control the derailment.  However, the engineer would have the ability to override it with full-train braking if there were some extenuating circumstance that made that advisable.   

[tree68]

Euclid

Do you think that everybody who has experience with derailments and trains agrees on everything? 

I think a good many of us agree your premise has no basis in real-world railroading.

[edblysard]

Euclid

tree68

The car involved will go from whatever speed to zero MPH within a few feet, ...

That is not true.  I recall seeing a car on the Milwaukee that derailed from a burned off axle and ran on the ground for 4 ½ miles undetected.  It broke the end off of every tie, clipped the corner off of every angle bar, and creased every tie plate for 4 ½ miles.  That kind of thing happens all the time.  The only way a car is going to dig in and stop in a few feet is if it is moving very slow, and is on its own with no cars on the rails behind it. 

Cite the source for this story please.

“Memories” don’t count, reliable print sources do.

[BaltACD]

The dead horse is still in pain!

[Euclid]

Ed,

I doubt that it was covered in the news, but I was there the day it happened, about 4 hours after it happened.  The dragging car was in the middle of a long train, and crew on either end did not see it.  It happend very early in the morning and may not have been light yet.  It was an eastbound train that dragged the car from just west of Chanhassen, MN to near Tower E-14.  It tore out two planked grade crossings along the way, one at Duck Lake Rd. and the other at Birch Island Road.    

In talking to people involved with it the next day, there was no sense expressed by them that this was anything unusual. 

[Overmod]

Euclid

The ECP brakes in this system will be controlled by wire, but will need some type of wireless backup for this derailment mitigation feature.  There won’t be multiple dynamiters, as you suggest, because the system will not dynamite the brakes in the traditional sense of a rapid loss of train line pressure triggering a pneumatic chain reaction of emergency braking.

There has been a great deal of frankly amusing criticism of Euclid's ECP-braked idea, with very little seeming knowledge of what he was actually saying.  Think of his system as having an individual brake controller on each car, which can be commanded either to apply or to release 'as appropriate' without any requirement for control latency.   This could easily be done with a wired 'bus' system like the CAN bus in vehicles (controller area network) but it's probably less expensive to do it with a modern parallel wireless protocol (say a modulation scheme similar to OFDM).  Then assume there is a computer system that calculates how every valve should be positioned, at least several times a second.  The 'innovation' in Euclid's system is that if his system detects a derailed car, it automagically modulates the brakes on a few of the cars to the rear of the derailment in such a way that they don't 'bunch' to the point slack effects start to happen, but slow down enough to maintain tension across the derailed car and keep it from being pushed out of line and start the accordion playing.  (Meanwhile, the head end brakes are applied just enough to keep the derailed car from pushing against the car in front of it, so In all probability the overall time it will take for the train to stop will be somewhat longer than a 'normal' commanded stop would be...)

The 'catch' is that in order for the system to have sufficient response characteristics to work, it must be capable of modulating the brake valves very quickly, and with sufficient power to get the brakes to apply net of all slack in the brake rigging within a comparatively short time.  And that means that if the computer system 'glitches', or is improperly coded and generates any one of a number of false signals, there can be very great problems developing in a very short time.

When I said 'dynamiters' I was not referring to overly sensitive conventional triples -- I was referring to what would happen if the computer system overmodulated the brake valves in the following cut of cars -- perhaps it was coded by the bright folks responsible for trains of zero length in NAJPTC and mistakenly assumes the cars each weigh 32,768 tons apiece, or its GPS goes to a different epoch and suddenly thinks it is descending a grade somewhere in Outer Mongolia -- so that the controller goes to full excursion as fast as its little dashpot lets it go (and as I noted, that has to be pretty fast for the system to work right as intended, as the latency between the actual derailment and the time the system has detected it, calculated a response, and had the commands confirmed is likely to occupy a critical length of time).  Or an engineer forgot to Gray code the signal coming off the encoder on a rotair valve, so one bad bit in a transmitted control signal produces a disproportionate degree of commanded rotation.  Anyone remember when an early BART car given an 8mph control signal read it as '88', went to full acceleration, and over the end of available track?

I might be somewhat less nervous if I knew the system was built and mainteined by skilled and motivated graduate engineers.  (Not to be disparaging of carmen, be it noted -- just that carmen aren't likely to recognize a great many of the complex interactions that might cause either dramatic overapplication or underapplication of the necessarily complicated response to an unpredictable derailment event.  Or understand when a computer system thinks it detects a derailment when one hasn't occurred... or misses one that has.)

Note that the 'optimum' brake response to a derailment situation is NOT necessarily going to be an emergency stop -- on the other hand, if the derailed truck 'digs into the ties' it might be a very short stop indeed, right up to what's commanded.

Which brings me to the electromagnetic track brake.

There have been versions of this, with VERY quick stopping time, around since at least the 1880s. One nifty version by Frank Sprague (of later MU control fame) involved a long 'shoe' parallel to the railhead, aligned by springs and levers, on a linkage of struts that would let it hinge down so the weight of the car would press the shoe material hard against the railhead.  This would be held up by an electromagnet, or a trip that would be released if the air pressure fell very quickly through 26 psi of reduction or whatever, or by some sort of inertia-switch arrangement:  it is not difficult to see that if this thing gets released, that car is going to STOP.  And a train composed of such cars isn't going to take much longer, even if there is considerable inertia involved.  The 'wrong' sort of bottom-feeding plaintiff's-bar attorneys have probably read all the old issues of Scientific American, and have figured out that the only real difference between stopping 1880s cars and modern ones is a difference of mass... so when evil railroad representatives talk about freight trains needing over a mile to stop, it's just one of those minimize-the-cost-of-a-human-life things...

... until you watch what happens when the brake releases unespectedly on just one car.  Or deploys on a curve, or on a train wrapped around a reverse curve, or deploys 'normally' and leaves a crew with 130 wedged-down shoes at one-dark-thirty and thunder and rain.  When a safety system causes more, or worse, accidents than the conditions it was intended to remediate, I not-so-humbly suggest that there may be a reason it wasn't more fully adopted.

[Euclid]

Overmod,

Thanks for your objective comments and for understanding what I am proposing.  Now that you have clarified your earlier comment, I understand your concerns about inadvertent dynamiting not being limited to the conventional pneumatically controlled air brake system. That would have to be worked out to prevent unintended consequences.  I am not sure about the fine points of individual car brake control with ECP brakes.  It may be conceptually possible, but not ever happen in practice.  The big benefit of ECP is that the brakes apply simultaneously rather than sequentially over a period of time as is the case with standard air brakes.  I would be very interested in learning about any research that goes beyond that and looks at applying the ECP brakes in an intended sequence for some reason. 

With what I am proposing, the braking is divided into two independent zones (ahead of and behind the derailment), but for the most part, the braking force would be retarded on the leading zone cars to keep them from resisting the trailing zone cars pushing into the derailed cars.  But a lot of control software would have to be developed, and some individualizing of the control beyond just the two zones might be desirable.   

I think the automatic derailment response system I am proposing should be capable of being overridden manually by the engineer in case it falsely senses a derailment and initiates without a reason.  The issue would not be that the system causes a violent stop that is unnecessary.  The derailment control brake application would actually cause a relatively slow stop in most cases.  

But if the automatic system had initiated and could not be overridden, it would prevent an emergency or harder stop from being made by the engineer if an actual emergency suddenly arose.  In that regard, there might be times when the system is properly responding to an actual derailment, and it becomes necessary to override it, and stop faster for another emergency regardless of the loss of control of the derailment in process.               

[dehusman]

Euclid

I doubt that it was covered in the news, but I was there the day it happened, about 4 hours after it happened.  The dragging car was in the middle of a long train, and crew on either end did not see it.  It happend very early in the morning and may not have been light yet.  It was an eastbound train that dragged the car from just west of Chanhassen, MN to near Tower E-14.  It tore out two planked grade crossings along the way, one at Duck Lake Rd. and the other at Birch Island Road.    

I suppose this was meant to justify the system Euclid is proposing.  I see it as actually pretty much the opposite. 

This situation presents the optimal situation for Euclid's system to work.  The derailed car remains upright, trucks in line, on the ties, and no further cars derail.

The thing I would suggest be considered is the outcome.  The cars didn't accordion.  The cars didn't pile up.  The train was brought to a stop.  In short, the derailment was "survivable".  Without ECP, without a sophisticated  air control system, without alignment control drawbars.  In short, without Euclid's system.  Euclid is designing a system to control a situation where the control isn't needed.  If you have the conditions to make Euclid's system work perfectly, then you have a situation where you really don't need Euclid's system to have a survivable outcome.

The question that has to be asked is why didn't the cars pile up?  What was the condition that allowed the "survivable" outcome? 

We don't know whether the train was stretched or bunched from the information we have.

What we do know it that the trucks stayed in line on the ties.  Maybe rather than controlling the braking we should figure out how keep the trucks from going off the ties?  If we keep the wheels on the ties we are more likely to end up with a survivable derailment.

Attach two pneumatic cylinders between the truck bolster and the frame/body of the car.  One on each side.  The cylinders would have the chambers on each side of the piston connected so as the truck turns, they vent from one chamber into the other so there is minimal resistance to turning in normal operation.  The arrangement should be constructed so when the piston is centered the trucks are running straight.  Use Euclid's derailment detector to detect when the car derails.  When the car derails, pressurized air/gas is vented into the cylinders, centering the pistons and steering the truck to run straight.  If you wanted really fast action, you could use the same technology as air bags to almost instantly create high pressures in the cylinders.  That would give you reaction times in the hundredths of seconds rather than seconds. The truck would be steered into a straight ahead line and the pressure in the cylinders would keep it straight.  Since the truck isn't on the rail, concern about the rigid truck failing to negotiate a curve isn't a problem.

If you want the derailment detector can initiate a penalty reduction to bring the train to a stop.

This solution can be retrofitted to existing cars.  It doesn't require dedicated train sets.  It doesn't require changing the car's couplers.  It doesn't require a new brake system.  It can work just as well in a train of conventional cars.  It doesn't require complicated communication protocols.  It could be made to have a very fast reaction time. It creates a more "survivable" situation.  Its a much lower cost system.  It addresses the root cause of a pileup.

Pretty much any situation that would overwhelm this solution would overwhelm Euclid's solution also.

[daveklepper]

I differ.  I think stopping the whole train, front to back, as quickly as possible without any additional damage, is by far the safest tactic, and the way to do it is with magnetic track brakes and all brakes controlled electrically.  Each tank car of a unt train would have one axle-driven generator, and a battery . The battery would normally be charged by head-end power, and both electrical control and power to charge batteries would be bult into the couplers, similar to those mu-car couplers that are also compatible with MCB-Janney standard couplers.   As with light rail, the magnetic track brakes would be an emergency use feature.  A derailment usually (not always) invovles a break-in-two.   Airbrakes would apply as in any break-in-to, but so would the magnetic track brakes.   Until battery power is depleted, the track-brakes would be powered from the battery, and in most cases the specific car would come to a halt before the battery is deplected.  But after it is depleted, if wheels are still turning, the axle-generator would suppliy power to the track brakes.   This tactic would come into play on emergencies on a donwgrade when the event occurs at normal track speed.  Without this feature, enormous batteries would be required.   Electrical equipment and batteries would be clad to insure zero possibility of any electrical fire.

I cannot see any situaltion where this would not be of benefit except:   If the event occurs mid-train or at the rear, and the main object is for the crew in the engine to get away as fast possible and get tanks at the front away as fast as possible, then the engineer immediateliy presses an override control, the rear of the train continiiues to stop as fast as possible and the front of the train accelerates away from the event  as fast as possible.

I hope BNSF or Fortress or someone will build such a safe unit tankcar train and run the tests on it.

[daveklepper]

OH YES, of course I do not object in anyway to ading Euclid's derailment sensing device.   With track brakes applying on each car, there should be no accordian effect.   Or only one or two cars behind the derailment, not the whole rest of the train.

[Overmod]

dehusman

Attach two pneumatic cylinders between the truck bolster and the frame/body of the car.  One on each side.  The cylinders would have the chambers on each side of the piston connected so as the truck turns, they vent from one chamber into the other so there is minimal resistance to turning in normal operation.  The arrangement should be constructed so when the piston is centered the trucks are running straight.  Use Euclid's derailment detector to detect when the car derails.  When the car derails, pressurized air/gas is vented into the cylinders, centering the pistons and steering the truck to run straight.  If you wanted really fast action, you could use the same technology as air bags to almost instantly create high pressures in the cylinders.  That would give you reaction times in the hundredths of seconds rather than seconds. The truck would be steered into a straight ahead line and the pressure in the cylinders would keep it straight.  Since the truck isn't on the rail, concern about the rigid truck failing to negotiate a curve isn't a problem.

Oh, great; let's put mandatory pyrotechnic charges on oil cars, and fire them whenever a computer detects what it thinks is a derailment.  Then let's center a three-piece truck by whacking on the bolster, with the wheelsets presumably derailed and leverage acting to skew the sideframes against the bolster.  And while we're at it, center it relative to the center sill of the car even if the train is traversing a curve.

I could go on, but that's really enough to can the idea.  Quickly, to minimize the shuddering...  ;-}

(I considered using servos years ago, to deal with issues of harmonically-driven truck skew/lozenging.  The cylinders would be driven so as to move the bolster counter to the skew moments and re-establish seating of the sideframes on the bolster, and the bearings in the sideframes.  Dropped the idea relatively quickly, because driving such a system out of perfect calculated phase might actually amplify the problem rather than solve it -- and there were other problems with the idea, too, that I won't go into.)

The basic idea of keeping truck frames relatively parallel to car underframes is probably just as well served with crossed progressive return springs and some sort of rotation lock, either actuated inertially or via the brake system if you want to allow a further degree of truck rotation on crossovers or whatever than the centering system would optimally allow.  But I'm still unsure as to how much this arrangement alone will keep derailed cars tracking 'away from parallel trains on adjacent tracks' -- or how it's somehow better than maintaining longitudinal tension across the derailed car, as Euclid's system purports to do.

[Euclid]

Dave Husman,

Regarding my description of a case in which a car was dragged on the ties for 4 ½ miles, let me clarify my point:

I did not intend this to be an example of something that my proposal would have prevented or even reacted to.  I agree that it is on the fringe of derailment occurrences.  And as you say, it did not develop into a pileup involving additional cars, so my derailment control concept would not have been needed in this case.  However, it does illustrate the kind of effect that my system is intended to produce with one or more derailed cars. 

But the main point of this long dragging event example is to show that a car does not instantly plow into the ties and stop on a dime just because it derails.

[daveklepper]

The correct derailment sensing device is simply a varation on diesel (and electric) locomotive slip control.   Instead of just one axle generator for emergency use of the magnetic track brakes if the battery is exhuusted by deceleration from speed on a downgrade, and any modern generator would be an alternator with rectification to avoid brush and commutator maintenance, have one for each axle and a frequency comparitor that would signal for an emergency application if there is great discrepency between rotating speed of one axle as compared with any of the other four.  This might protect from some other problems besides derailments.

Remember that with magnetic track brakes and electric application of brakes, indeed the whole train stops as a unit, with NO accordianing or breaking in two or pulling off on the concave side of a curve.

I am assuming decently maintained equipment, all of the same characteristics throughout the train.  This whole system is for unit oil trains and other unit hasmat trains, not for loose car railroading by any means.   Alhtough electric control of braking would benefit loose car railroading, to try to calibrate the magnetic track brake forces for different cars with different weights would be very complicated and failure to do it properly could result in train handling problems, in an emergency, that would really complicate its usefulness.

[schlimm]

The current cars leak even without derailing (12,000 gallons along the CP south of Red Wing, MN):

http://www.winonadailynews.com/news/local/gallons-of-crude-oil-spilled-between-winona-and-red-wing/article_850d10d2-a702-5fc8-b97e-f822d0c5c30b.html

[Paul of Covington]

   I have never worked for a railroad, but I thought I might throw in a couple of comments.

   All this talk of sophisticated electronic devices is fun to think about, but having worked on electronic and electro-mechanical stuff, I can't help thinking about how robust this equipment is going to have to be.   The railroad environment is very severe, with dirt, moisture, flying gravel, extremes of temperature, repeated jolts, etc.

   In my experience false error detection seemed to be about as common as real errors.   Considering the rough environment this may be more of a nuisance than help.

   Going back to the idea of controlling the braking differently ahead of and behind the sensed derailment, how would the instructions be conveyed to the individual cars?

[daveklepper]

Paul, none of this is new technology.   Electric control of braking is standard on all mu-cars and has been for over 100 years, ever since Frank Sprague electrified the Southside "L:in Chicago.  It is actually more rugged, not less, than airpipe control of braking, but the catch for both is the connection between cars where both systems face the same problems.   And wheel-slip detection on diesel and electric locmotives has been around for about 50 years, and the componants are rugged, proven, off-the-shelf, and all that would be required for derailment detection would be calibration to not act until differences are somewhat greater.  I noted on earlier post that magnetic track brakes were in use on interurban cars of the West Penn from 1912, and some of these cars were still lin use at the end of service in 1953 with the same equipmenet intact and in good condition.   Western PA has plenty of ice and snow and sleet.   The result would be unit oil trains that would be safer than conventional manifest trains because they could stop as quckly as any truck, actually a lot quicker in ice or snow or rain.  Possibly as quickly as a private automobile on dry pavement.    

[Euclid]

Paul of Covington

   All this talk of sophisticated electronic devices is fun to think about, but having worked on electronic and electro-mechanical stuff, I can't help thinking about how robust this equipment is going to have to be.   The railroad environment is very severe, with dirt, moisture, flying gravel, extremes of temperature, repeated jolts, etc.

 

Going back to the idea of controlling the braking differently ahead of and behind the sensed derailment, how would the instructions be conveyed to the individual cars?

The severe conditions of the railroad environment do indeed require extra robustness in terms of the electronic hardware features for ECP brakes, particularly with plug connectors that would be routinely connected and disconnected on loose car ECP applications. 

With ECP, the individual cars have their brakes controlled by an electronically controlled, electrically powered valve that takes the place of the pneumatically controlled, so-called “triple valve” of the conventional air brake system. 

With the system I am proposing which separates the braking into two independent ranges, this information is conveyed to the ECP brakes via the normal electronic transmission cable from car to car.  This information would be developed by a central processor that would know where the derailment is located, and so it would know where to split the braking function.

[tree68]

Euclid

This information would be developed by a central processor that would know where the derailment is located, and so it would know where to split the braking function.

And how, pray tell, will the processor know which car is where?  If a car is bad-ordered and set out, how will the processor make the necessary adjustments?

If the processor has to talk to each individual car, what will be the response time for the data to all the cars?  Will there be some form of confirmation to the processor so it knows all cars have received the instructions?  

If you're talking wireless, what kind of range will the main processor and the individual cars have?  If you're talking car-to-car relay via radio, what will be the failsafe if one car's processor fails?