Oil Train

[dehusman]

ruderunner

Lets define derailment, basically the flanges are no longer both between the rails. It doesn;t have to include a big flaming pileup (though thats what the general public thinks)

That's not an inclusive definition.  If there is wide guage or a loose wheel you could have both wheels between the rails.

And frankly if the trucks aren't pointed the same direction that the carbody is, wouldn't that indicate a derailment?

Frankly no.  The only time the trucks will be pointed the same way the car body is is when the car is on tangent track.  If the car is on any type of curve the trucks will be pointed differently from the carbody, and the trucks will only have the same rotation (in opposite directions) when they are on the circular portion of a curve.  When they are in switches, turnouts or spirals the trucks will have differing amounts of rotation.

[dehusman]

ruderunner

Paul thank you for that reference. I'm still curious of how much deflection a truck with one wheelset off the rails has. 

 

 

It could have no deflection (one wheel fallen in). 

 

If the wheel tread is 4" wide and the truck wheelbase is 6 ft, and both wheels of one set are derailed, then its about a 7 degr angle.

 

If both axles of the truck are derailed and its running along the ties then its about a 6" deviation in a 40 ft truck centers or about 2/3 degr deflection.

Also what would normal track speed be in that 23degree curve?

Assuming minimal superelevation, somewhere in the 10 mph (or less) range.

[dehusman]

Ruderunner's plan assumes that the truck will be rotated MORE than the car or the other truck.

What happens when the trailing axle derails the truck is rotated LESS than the other truck?

The rear truck is rotated 3 degr and the lead truck is rotated 1 degr.  Niether would hit the limit switches.

[Euclid]

Here is a mechanical derailment sensor that does appear to monitor the position of the truck rather than detecting vibrations.  Apparently the rectangular metal pan allows a feeler pin to move over its area, as the normal range of truck motion encompasses.  Somehow a derailment disrupts this physical relationship of the pan and feeler pin, which causes an emergency application of train brakes.    

 

I am not sure if that is also measuring movement of truck pivot.  But, in the derailment video segment, the truck pivot is involved and this device is reacting to it.  Actually, the way the device is positioned, it would have to have enough clearance to allow truck pivot whether it measured it or not.  The overall explanation is highly detailed, but not 100% clear in the sensing mechanics.    

 

https://www.youtube.com/watch?v=VEzsEQHkQ-Y

[Wizlish]

Euclid

Here is a mechanical derailment sensor that does appear to monitor the position of the truck rather than detecting vibrations. Apparently the rectangular metal pan allows a feeler pin to move over its area, as the normal range of truck motion encompasses. Somehow a derailment disrupts this physical relationship of the pan and feeler pin, which causes an emergency application of train brakes.

Oh, fer crying out loud, the "pan" is just a multiaxis ramp mounted on the truck frame.  If it moves too far in any direction it depresses the pin on the valve, which puts the brake in emergency (probably acting much like the tripper valve on a NYC subway car).  Note that this is mentioned as being a simple, pure pneumatic system, with no proportional or electrical logic, etc.  There are some comparatively simple enhancements to this idea that I think will prove very effective in control of an ECP brake.

[Rather obvious potential improvements: curve the 'pan' slightly so the pin follows in 'register', and make the pan specially shaped in perimeter to control vertical vs. rotary deflection (or discriminate curving vs. skew vs. rotation) before the system is triggered...]

I hope folks reading this thread pay careful attention to the claims made in that video from about 4:45 onward.  Among these: the device has already been installed on over 1000 cars, and is claimed to have worked correctly in "100%" of the events (presumably derailments) experienced so far.

Personally, I think the system needs a critical modification: if it puts the train brake in emergency, it should also reduce brake pressure on the truck whose detector has been actuated.  Full emergency application of braking on a derailed truck is NOT likely to produce deceleration of the right kind -- is the foundation set up to pull the truck roughly into parallel alignment with the car frame and hold it there?

[Euclid]

 

Wizlish

Oh, fer crying out loud, the "pan" is just a multiaxis ramp mounted on the truck frame.  If it moves too far in any direction it depresses the pin on the valve, which puts the brake in emergency (probably acting much like the tripper valve on a NYC subway car). 

That was my general perception of how the pan works.  However, let me ask this:  In the derailment video, the pan drops far enough to have its upper side contact and compress the feeler pin.  So that would trigger a brake application.

But before the pan drops, it pulls away from the feeler pin as the derailment pulls the wheel far enough inward to allow it to drop inside of the rail.  So before the pan can trigger the feeler pin by dropping, the pan pulls several inches away from the pan horizontally.  The pan only looks to be about an inch deep.  How can it pull several inches away from the feeler, and still engage the feeler as is drops after pulling away? 

And for that matter, how does the truck pivot when a pivot would force the pan into the feeler pin and its housing?

 

[Wizlish]

I think we are looking at a 'cartoon' CGI animation of the system, not an accurate illustration of how the parts are arranged.

I was assuming that the ramps that are the periphery of the 'pan' act as a limiting surface of the 'envelope' of permissible truck rotation and excursion.  Part of why I think the pan should be curved is to ensure, as you noted, that if the truck frame drops inside and down the relevant section of the ramp surface doesn't get pulled out and away to the point the valve won't be triggered.  But I feel sure the Spanish developers are not fools and have arranged the physical pans used (on three-piece trucks, at least -- the problem doesn't seem as pronounced for the passenger-car trucks illustrated) so that any substantial truck motion away from 'railed' tracking compliance will fire the valve.  Is there a failure mode of a three-piece truck in skew that would allow the pan to be pulled away from the pin before the ramp edges could reach it?  If so, the system should be modified to correct that situation (perhaps by puting a little preload on the valve pin. relaxing of which would also open some percentage of the valve area in release?)

Personally I think it would be interesting to look at all the dynamic motions a truck might assume in a derailment, and see what configuration of 'pan and pin(s)' might work to a sensible number of 'nines' confidence...

[Euclid]

Yes, it would be interesting to see all of the possible truck derailment scenarios and consider how they would trigger this device.  It does seem like the pan should be curved as a segment of a vertical cylinder that is coincident with the truck pivot circle.  There is a camera video of the actual sensor mounted and responding to a derailment starting at 3:22.  As I look at it again, it looks like the pan might be set on the truck pivot circle.  So mayby it really does not pull away from the feeler pin. 

I wonder if this detector assumes that every derailment begins with one wheel and that is the one the triggers the brakes.  What if the whole truck derailed all four wheels at the same time?  Where would the relative movement come from between the truck frame and the car frame?  I suppose it might detect a big spring bounce, but I wonder about that.     

I agree with your point about the risk of triggering an emergency brake application as a truck derails.  I mentioned a few pages back that I felt that this type of derailment sensor could actually cause a pile up that would not have happened had there been no derailment sensors.

However, I have been informed that the only thing that can perturb a derailed, dragging truck to start a pileup is another derailed car.  But I am not sure how to reconcile that because I have always heard that emergency applications can cause a derailment.  And I would think that a derailed, dragging truck would be particularly vulnerable to being disrupted into chaos by an emergency brake application. 

There are references that describe a hard slack run-in being caused by initiating an emergency application from somewhere mid-train, near the head end.  Any hard run-in introduces a force that wants to buckle the train if it can overcome the guidance of the wheels.  That guidance disappears from a truck that derails.  So why would you want to trigger an emergency application that has a good chance to introduce high buff force right at the spot that can least tolerate it?

But I don’t see a way for the derailment detector to tell the brakes not to apply on the derailed truck.  That capability would require ECP brakes. 

[Electroliner 1935]

This device seems to meet the kiss principle (Keep It Simple Stupid) in that it doesn't require batteries or many active parts. There are two pans, one on each side of the center of the truck in the proximity of the actuators where displacement of the truck in any direction from its accepable position will contact one or the other actuator. The video shows a conventional freight truck. How it would old up in all of the weather conditions an oil train might experience from -40 degrees and deep snow in North Dakota to the summer heat remains to be tested. Ice & smow buidup could cause false activations. Looks to me like it's worth a trial. Could someone stage a derailment on an equiped train at Pueblo?

[dehusman]

Euclid

However, I have been informed that the only thing that can perturb a derailed, dragging truck to start a pileup is another derailed car. 

You have been grossly misinformed.  Cars pile up when the cars leave the track structure or otherwise get significantly out of line where the forces can start rotating the car or cars.

But I am not sure how to reconcile that because I have always heard that emergency applications can cause a derailment.  And I would think that a derailed, dragging truck would be particularly vulnerable to being disrupted into chaos by an emergency brake application. 

Yes an emergency application can cause a train to derail.  In relatively rare cases (I can't think of one off hand in the last several years.)  Generally there is a risk in general freight trains where there is a wide mix of car weights and car lengths.  Niether of those apply to unit trains.

Any system that causes in train forces cause an empty car to pop off.  All of these proposals that maximize the braking effort have the possibility of causing a derailment by inreasing the stress in the train.

If there is a situation where there is a safety risk then by all means you want to try and get the train stopped as soon as possible.  If there is a car stuck on the tracks then yes you want to plug it it to stop the train.  But railroads don't want false positives, they don't want the train going in emergency if there isn't a risk.  An air bag can injure you when it goes off.  But if you are in a head on collision you want it to go off.  The event causing the air bag to go off has a higher injury risk than injury by the air bag.  But you don't want it going off at times when there isn't a risk.  

 

[Norm48327]

[Euclid]

dehusman

 

Euclid

However, I have been informed that the only thing that can perturb a derailed, dragging truck to start a pileup is another derailed car. 

 

 

 

You have been grossly misinformed.  Cars pile up when the cars leave the track structure or otherwise get significantly out of line where the forces can start rotating the car or cars.

 

But I am not sure how to reconcile that because I have always heard that emergency applications can cause a derailment.  And I would think that a derailed, dragging truck would be particularly vulnerable to being disrupted into chaos by an emergency brake application.

That information came from you a few pages back.  So, if we set that aside, then I don’t need to reconcile it.  I understand your other points here about quicker stopping being a double edged sword.  ECP brakes would stop quicker, and when considered in a vacuum, that would increase potential in-train forces.   But ECP also fundamentally reduces in-train forces because of its simultaneous application.  So I suspect that overall, ECP reduces potential in-train forces.  Empty/loaded sensors would result in quicker stops, resulting in potentially greater in-train forces, but if combined with ECP, I would expect that to mitigate the higher in-train forces from quicker stopping resulting from empty/load sensors.

 

When will we learn the exact causes for the four oil train derailments in the U.S. following the collision in Casselton, ND?

[tree68]

dehusman

Any system that causes in train forces cause an empty car to pop off.  All of these proposals that maximize the braking effort have the possibility of causing a derailment by inreasing the stress in the train.

Witness the story in Trains about the tank car that popped out of a consist on a grade on the SP Coast Line.  I think that was a recent issue - sometimes I dig out old issues are re-read them...

Were it not for the disconnected brake line, the report of a missing car from the receiving yard, and an observant track man, nobody would have missed it - it went far out of sight off the ROW.

And that was simple slack run-in.

[Wizlish]

dehusman

Any system that causes in train forces cause an empty car to pop off. All of these proposals that maximize the braking effort have the possibility of causing a derailment by inreasing the stress in the train.

But the purpose of the exercise is not to maximize the braking effort, it's to minimize the safe stopping distance.  With much more emphasis on 'safe' than on just 'minimized stopping distance'.

As with antilock brakes, the usual result is that the braking distance will be longer than if all the brakes on the train exerted their maximal achievable retarding force ... but the tradeoff is that train dynamics can be greatly improved or even optimized under given conditions.

I would argue that putting a train with derailed cars in emergency is already a bonehead idea.  The most that can be said for it is that you'd have plausible denial when the lawyers tried to say you were negligent for not stopping the train on a dime, and you have the flat wheels and jackknifes to prove your zeal to try achieving that. 

It's one thing to try to stop short of a collision or an obstruction on the track ahead of you, or to avoid a SPAD or ATC/PTC violation.  There, scrubbing off as much kinetic energy as you can makes reasonable sense in most contexts.  It is something quite different when you have the analogue to a tire or wheel coming off a vehicle you're driving at speed.  Think about it...

[Euclid]

Wizlish,

 

That is right on.  I agree with your points 100%.  When the first car derails, it may drag for miles and never progress to a pileup; or it may pileup at the moment it derails.  Once a pileup begins, it may make sense to brake the train as hard as possible because the more kinetic energy that is dissipated braking, the less will be available to shove cars into the pileup.  The one exception would be if the cars ahead of the derailment happen to develop more braking force the cars behind it.    

 

But when the car is only derailed and dragging, I see a lot of risk that dynamiting the brakes in both directions from that derailed car will cause it to jackknife and begin a pileup.  It does seem like a boneheaded idea, as you say. Yet, we have looked at two different derailment sensors that do just that.  Of course, they offer simplicity, but it comes with a big risk of making a problem worse rather than better.

 

For this reason, I favor adding derailment sensors on top of ECP brakes.  Some seem to conclude that an emergency application is the best course of action.  It is a safe conclusion with conventional air brakes because it is the only course of action available. 

 

With ECP brakes, however, there are many options of brake application available besides just an emergency application.  Certainly ECP could withhold heavy application upon the sensing of a derailment, before the wire is broken.  But it can also withhold heavy application after the wire has broken at the onset of a pileup.  It is not locked into to an all or nothing response like conventional air brakes.

 

So ECP can react ideally to a derailment and dragging car, and also react ideally to the development of a pileup.  And also, because it reacts simultaneously to all cars in the train, there is less chance of producing in-train forces, which the more delicate braking is protecting against.     

[dehusman]

It's one thing to try to stop short of a collision or an obstruction on the track ahead of you, or to avoid a SPAD or ATC/PTC violation. There, scrubbing off as much kinetic energy as you can makes reasonable sense in most contexts. It is something quite different when you have the analogue to a tire or wheel coming off a vehicle you're driving at speed. Think about it...

I don't see as much of a difference as you do, I see them as much the same, the major difference is the SPAD/collision/obstruction is something in front of the train and the derailment is something within the length of the train. Part of the reason this whole discussion is so pointless is everybody's trying to figure out what to do with the car and the train after its already derailed, but very few people are looking at the derailment and its cause. You can't put the manure back in the donkey.

If you have a derailed car, you have had something bad happen to cause the car to come off the rails. That generally means the track is damaged or obstructed, or when the derailed car moves, it will damage or obstruct the track. Either way if the cars behind the first derailed car move, they will enter the damaged track area. That means they too will derail and also damage the track. The more cars you pour into the damaged area, the more the area will be damaged and the more chances there are the derailment will get progressively worse. This will happen whether the train slows quickly or slowly. Decelerating at a slower rate means each successive car hits the damaged area harder (more kinetic energy) and there are more cars that will hit the damaged area. Shoving more cars into a hole at a higher rate of speed will not improve the situation.

The only time stopping more slowly is beneficial is when the defect is not in the track itself and when the derailed car is not going to do a lot of track damage (such as an empty car with shelf couplers). In that subset of occurrences, stopping the train slowly is a better option. If the cars are loaded, the chances of increasing track damage are higher. None of the oil train derailments under discussion involved empty cars.

The trick to deciding when to put the train in emergency, of course, is detecting when the right conditions have been met and doing it soon enough that you can make a decision on whether to make a service reduction or an emergency reduction before the situation makes the decision for you.

Until that decision can be made in a timely manner, the system is set to stop everything as soon as it can, because in most cases that is a the better action.

[oltmannd]

Euclid

Here is a mechanical derailment sensor that does appear to monitor the position of the truck rather than detecting vibrations.  Apparently the rectangular metal pan allows a feeler pin to move over its area, as the normal range of truck motion encompasses.  Somehow a derailment disrupts this physical relationship of the pan and feeler pin, which causes an emergency application of train brakes.    

 

I am not sure if that is also measuring movement of truck pivot.  But, in the derailment video segment, the truck pivot is involved and this device is reacting to it.  Actually, the way the device is positioned, it would have to have enough clearance to allow truck pivot whether it measured it or not.  The overall explanation is highly detailed, but not 100% clear in the sensing mechanics.    

 

https://www.youtube.com/watch?v=VEzsEQHkQ-Y

 

Take a guess what the number one cause of brake actuation would be on this system in NA?

 

[Murphy Siding]

oltmannd

 

 

Euclid

Here is a mechanical derailment sensor that does appear to monitor the position of the truck rather than detecting vibrations.  Apparently the rectangular metal pan allows a feeler pin to move over its area, as the normal range of truck motion encompasses.  Somehow a derailment disrupts this physical relationship of the pan and feeler pin, which causes an emergency application of train brakes.    

 

I am not sure if that is also measuring movement of truck pivot.  But, in the derailment video segment, the truck pivot is involved and this device is reacting to it.  Actually, the way the device is positioned, it would have to have enough clearance to allow truck pivot whether it measured it or not.  The overall explanation is highly detailed, but not 100% clear in the sensing mechanics.    

 

https://www.youtube.com/watch?v=VEzsEQHkQ-Y

 

 

 

 

Take a guess what the number one cause of brake actuation would be on this system in NA?

 

 

  Hot air? 


(Sorry man- the made me do it.)

[Euclid]

This is a system of oil train enhancement to increase safety.  It has four stages that are interrelated:

1)    ECP brakes with wire control.

2)    Enhanced load braking force combined with empty/loaded sensors.

3)    Derailment sensors.

4)    Differential braking.

 

These are the specific benefits:

Item #1 reduces derailments, mitigates pileups, mitigates tank car breaching, and is the platform for items #2-4.

Item #2 mitigates pileups and mitigates tank car breaching.

Item #3 mitigates pileups and mitigates tank car breaching, and is the platform for item #4.

Item #4 mitigates pileups and mitigates tank car breaching.

 

For item #4, I am not suggesting a major reduction in braking that will significantly increase the stopping distance.  But that notion seems to have taken hold in this discussion.  The concept only basically assures that there is less braking ahead of the derailment than behind it.  It is intended to address the derailment in the dragging car phase, before a pileup begins.  Not every first car to derail immediately does enough track damage to derail the following cars. 

But even though item #4 increases stopping distance somewhat, item #2 does the opposite.  So with this whole system, the stopping distance may be less than with the present air brakes and practice; and yet it will also baby the derailed car rather than jackknife it or stand it on end.    

[ruderunner]

Zugman, do I really have to explaig that doing something you know is wrong versus something that might be wrong?

[zugmann]

ruderunner

Zugman, do I really have to explaig that doing something you know is wrong versus something that might be wrong?

 

 

You could try telling me what you are talking about.  I have no clue.

[Murphy Siding]

zugmann

 

 

ruderunner

Zugman, do I really have to explaig that doing something you know is wrong versus something that might be wrong?

 

 

 

 

 

You could try telling me what you are talking about.  I have no clue.

 

 I'll second that.  I went back and tried to figure out what you were refering to and came up blank.  Can you explain please?

[ruderunner]

Euclid

This is a system of oil train enhancement to increase safety.  It has four stages that are interrelated:

1)    ECP brakes with wire control.

2)    Enhanced load braking force combined with empty/loaded sensors.

3)    Derailment sensors.

4)    Differential braking.

 

These are the specific benefits:

Item #1 reduces derailments, mitigates pileups, mitigates tank car breaching, and is the platform for items #2-4.

Item #2 mitigates pileups and mitigates tank car breaching.

Item #3 mitigates pileups and mitigates tank car breaching, and is the platform for item #4.

Item #4 mitigates pileups and mitigates tank car breaching.

 

For item #4, I am not suggesting a major reduction in braking that will significantly increase the stopping distance.  But that notion seems to have taken hold in this discussion.  The concept only basically assures that there is less braking ahead of the derailment than behind it.  It is intended to address the derailment in the dragging car phase, before a pileup begins.  Not every first car to derail immediately does enough track damage to derail the following cars. 

But even though item #4 increases stopping distance somewhat, item #2 does the opposite.  So with this whole system, the stopping distance may be less than with the present air brakes and practice; and yet it will also baby the derailed car rather than jackknife it or stand it on end.    

 

OK I'm going to jump in again here.  I agree with Eiclids idea, especially the differential braking aspect.  But I temper that with the fact tha ECP is not widely accepted yet (in 20 years who knows?)

To catch up on post since I last had a chance to actually type...

Tree68: no personal attack felt, but sometimes we need to think outside the box(car)... Whats your opinion on how much truck deflections is acceptable?

Northwest: good point but how does that compare todoing nothing?  Is status quo acceptable?

Dhuesman and Zugman:  yes I understand that emergency is currently yhr fatest way to stop s trsin.  But what if we could make it stop faster? Load empty valves allow that. 

DH you examle of welded rail in long lengths is mostly correct in asmuch as it minimizes (not ELIMINATES) the risk of bad welds and weak joints.  Nor does it eliminate the risk of bad rail or poor installation.  A step forward but not infallible.  That said:that's a MOW problem and I think thy are doing a good job as is.  Could it be better? sure but at what cost?

Oltmand: I think you understand my point about load empty valves. But I have to aske, what is the current  "failsafe" of those valves?  Is it maximum braking?  is it empty limited?  And yes ECP could overcome the problems now associated with L/E vales but I think thats a long time coming.

Questions for all:  Since someone pointed out that the air generators for the derailment sensors may consume too much air, I've rethought using axle mounted generators. Or more preciecsly sideframe mounted.  Here's the question: is the three bolt bearing cap standard? Meaning is the patterns of those bolts the same regardless of truck/axle/bearing manufacturer?  My guess is yes it'sstandard and that would be a boon to my revised axle generator idea.

In regards to 23 degree curves and a derarilment at 10 mph, whats your opinion on how detremental that would be? Obviously not a giant flaming pileup, but certainly an inconvieniece.  But how dangerous?

DH: I see we disagree on what constitutes a derailment.  But I'm unclear on your examples, especially of the wheels getting between the rails.  Wide guage I understand ( or rolled over rail etc) but you seem to imply that the wheels can move closer together on the axle.  Isn't the axle machined with a step that would provide a positive stop for the wheels to prevent them from moving inboard?  By the same token, wouldn't the sideframes and bearings prevent the wheels from spreading? Not counting catastrophic failure of the axle or wheels I'm not seeing what you're getting at.

Provided the wheels are at the right spacing and the rails are too, how could the truck not deflect? 

And yes the trucks trucks will not be inline with the car when rounding a curve,but wuoldn't both trucks be deflected the same amount (not counting switches, crossovers and transitions) which is why I mentioned a timer.  The timier would allow for some distance of tavel into a crossover, transition etc where the system would not produce a derailment essage.  How long does the average train car take to enter/pass a crossover/switch/transition?

Remeber, I figured a "switching" mode which would mute the alarm during slow speed tight trackwork business.  This could be automated using an axle mounted genrator since that would provied a "built in" speed sensing circuit.  By built in I mean the control board coud sense ow sped operation and shut itself off but automatically rearm as speeds increase.

Euclid: I belive that most derailments star with one axle off the rails, provided that deraiment isn't caused by a rolled over rail or somting similar that throws the truck to the ground simultaneously. I agree that avoiding setting the brakes on a derailed truck would be beneficial, but that would require a redesign of the current brake system and likely multiple cylinders. Ideally you would want 1 cylinder per axle but even 1 cylinder per truck get cost prohibitive.

Wizlist: yes stopping the train safely versus fastest is the goal.

DH: just because one truck has derailed doesn't automatically mean the follwong cars wil also derail.  If it due to poor trackwork, then yes the likelyhood is higher but it's not a given.  Review Trre68 story about the roadrailer that rerailed on its own.  It's not anisolated incident unusual yes but not a freak of nature.

Euclid keeps going about ECP, and I agree with him that that is something that needs to happen.  Probaby not in the next 10 or 20 years, but maybe 30 years down the line.  The big advantage that ECP carries isn't just shorter stopping distances that are advertised now, but what could potentionally bencome of it.  Adding the basic electronic controls is the first step, then things like built in/automated load empty controls can be added, the Euclids differntia braking (which is similar to stretch brakingof passenger trains) could be added.  It's a whole new ball of wax with ots of possibilities.  Ju7st not very practical at this time due tocost, acceptance, and complexity.  I liken this to the advent of ABS in automobiles, the original systems were crude and not very effective.  But time and technology moved on and now the basic ABS system includes traction control (think wheelslip detection) and stability control (keeps you from spinning out/rolling the vehicle over).  These are analogous to derailment detection, improved emergency braking and even derailment avoidance.

And I suppose I'll chime in on my views of the inter train forces under braking.  Lets take the fact that we have discussed that car brakes are designed to maximize braking force for empties.  And by the same token that loaded cars are effectively underbraked because os that.  That means 2 empties are going to have similar deceleration rates under braking, and 2 loads will have similar decelerations rates under braking  but a load will have a much lower rate of decelartion than an empty.  And if a load is behind an emty, the load will run into the empty and try to push it.

So lets build 3 trains, one a unit train of empties, onea unit of loads and one mied freight of empties and lods.  Which would be the most likely to derail in an emergency stp?

[ruderunner]

Re read your own posts Zugman.  Square wheels is a definite way to cause derailments.  Not only the sliding action tearing up the rails but the ultimate in floatsptooting tearing them up.  Once the rails are damaged beyond use, derailments are sure to follow....

Doing something you know is wrong is akin to sabatoge.

Gee whiz guys, I had to explain that to you?

[zugmann]

ruderunner

Re read your own posts Zugman.  Square wheels is a definite way to cause derailments.  Not only the sliding action tearing up the rails but the ultimate in floatsptooting tearing them up.  Once the rails are damaged beyond use, derailments are sure to follow....

Doing something you know is wrong is akin to sabatoge.

Gee whiz guys, I had to explain that to you?

 

 

If you think that was a serious suggestion, then I am just going to step out of this conversation.  You are either trolling,  or I don't know what....

 So yeah, gee-whiz.

[dehusman]

ruderunner

That said:that's a MOW problem and I think thy are doing a good job as is.  Could it be better? sure but at what cost?

All the "solutions" on this thread address what to do AFTER the cars are derailed.  The welded rail examples eliminate causes so the derailment doesn't happen in the first place.  Since track problems are a major cause of derailments, eliminating track problems is a major accomplishment.  Installing all the stuff you guys want on one set of equipment benefits that one set of equipment.  Improving the track benefits every car of every type that passes over it.

Questions for all:  Since someone pointed out that the air generators for the derailment sensors may consume too much air, I've rethought using axle mounted generators.

Then again you guys are not operating with any data so you don't have any idea whether that is true or false or how much air one of those generators consume.

DH: I see we disagree on what constitutes a derailment.  But I'm unclear on your examples, especially of the wheels getting between the rails.  Wide guage I understand ( or rolled over rail etc) but you seem to imply that the wheels can move closer together on the axle.

A derailment is anytime the wheel leaves the rail.  Very simple concept.

A wheel can come loose and move inward.

How long does the average train car take to enter/pass a crossover/switch/transition?

Could be hours if its stopped.

DH: just because one truck has derailed doesn't automatically mean the follwong cars wil also derail.  If it due to poor trackwork, then yes the likelyhood is higher but it's not a given.  Review Trre68 story about the roadrailer that rerailed on its own.  It's not anisolated incident unusual yes but not a freak of nature.

100% of derailments start with only one truck derailing.  Only a very few end with just one truck derailing.  Yes having one truck derail is not unknown.  there was one las week.  But in that case, as in the Roadrailer incident and in the vast majority of all of those type of derailments, the derailed car is an empty (or a very light piece of equipment).  As i have pointed out several times now, NONE of the oil train derailments we are discussing involve empty cars, ALL of them involved loads, ALL of them involved multiple cars and trucks derailing.

And I suppose I'll chime in on my views of the inter train forces under braking.  Lets take the fact that we have discussed that car brakes are designed to maximize braking force for empties.  And by the same token that loaded cars are effectively underbraked because os that.  That means 2 empties are going to have similar deceleration rates under braking, and 2 loads will have similar decelerations rates under braking  but a load will have a much lower rate of decelartion than an empty.  And if a load is behind an emty, the load will run into the empty and try to push it.

How many oil train derailments have been caused by the slack running in?  ZERO.
How many derailments a year are caused by slack during heavy braking?  A tiny, tiny fraction.  Less than 1%.

You guys are trying to figure out how to put out a candle while there is a 4 alarm fire buring right behind you.

So lets build 3 trains, one a unit train of empties, onea unit of loads and one mied freight of empties and lods.  Which would be the most likely to derail in an emergency stp

 That's real easy.  The mixed freight. would be most likely.  If built properly according to the rules maybe one or two out of every thousand, couple thousand stops you would get a wheel on the ground.  Of course since you were in the process of stoping it would only be one or two cars so it wouldn't be a major derailment.

 

[Murphy Siding]

ruderunner

Re read your own posts Zugman.  Square wheels is a definite way to cause derailments.  Not only the sliding action tearing up the rails but the ultimate in floatsptooting tearing them up.  Once the rails are damaged beyond use, derailments are sure to follow....

Doing something you know is wrong is akin to sabatoge.

Gee whiz guys, I had to explain that to you?

 

    If you could somehow interpret that post that way,  I have to seriously doubt the thought process behind anything you would post.  Floatsptooting indeed!

[ruderunner]

Murphy Siding

 

 

ruderunner

Re read your own posts Zugman.  Square wheels is a definite way to cause derailments.  Not only the sliding action tearing up the rails but the ultimate in floatsptooting tearing them up.  Once the rails are damaged beyond use, derailments are sure to follow....

Doing something you know is wrong is akin to sabatoge.

Gee whiz guys, I had to explain that to you?

 

 

 

 

    If you could somehow interpret that post that way,  I have to seriously doubt the thought process behind anything you would post.  Floatsptooting indeed!

 

 

Sorry, flatspotting, just a typo.

Zug was being facietous. I know that, but I simply wanted to be clear about my statement that doinsomething, even if its wrong does not include doing things you already know is wrong. Not every suggestion is the best way to deal   with the situation but the only way to get to the best answer is to try a few things that may or may not work well, then refine the idea and try again.

[ruderunner]

Dave, I'm not saying it needs yo be limited to only oil trains forever, just that they would be a good test bed. Eventually such systems could be added to the entire fleet.

And what's wrong with attempting to do something after a wheel has left the rail? Are you suggesting that we do nothing at all to prevent a minor derailment from turning into a major one?

And no I dont have any idea how much air a generator would use, hence I'm keeping options open. If you have hard facts please share.

And re definition of derailment, isn't that pretty much what I said. I think we agree here.

Re stopped trains, OK so a speed sensor would be beneficial, not a challenge.

Also perhaps we aren't discussing empty oil train derailment since they generally dont catch media attention. No big fireball makes for not catchy headlines. That doesn't mean empty oil trains dont ever derail.

You candle vs fire argument is interesting. You do realize that a large fire can be started with just one unattended candle? I'd like to put out the candle before the oil catches fire.

[Euclid]

I agree that if you can prevent derailments in the first place, it is the best way to solve the problem.  There is no point in trying to control them if you can just prevent them.

But the problem is so multi-dimensional that nobody expects one single approach to solve it.  Wayside detectors and track inspection will help, but can never solve the problem completely.  I think it is also clear that making tank cars stronger is not going to solve the problem completely.

So with the uncertainty of getting tank cars able to be high-speed crash-proof, and the present limits in lineside detection, what is the solution?  I see a solution gap.  The solution needs to be multi-faceted in order to reduce the problem as much as possible. 

The solution is not to focus only on the top level cause, and say that if we prevent that 100%, we will end derailments 100%.  The reason that is fallacious is that it will be impossible to prevent the top level cause 100%.

So let’s say the maximum wayside detectors and track inspections solve 80% of the problem.  Do you just stop there because if that top level measure worked 100%, it would solve the problem 100%?

When I suggest a range of measures in relation to ECP brakes, I am certainly not saying that they should be implemented instead of wayside detection and track inspection.  Everything that can help needs to be done until the problem is perceived to be reduced to an acceptable level.  So if the top level measure only provides 80% of the solution, I think other measure are justified if they address the remaining 20%.