Oil Train

[Euclid]

tree68

 

Euclid

I have only said that it is possible.  You seem to imply that it is not possible, since you always refute my suggestion that it is possible.  But you have never explained why it can’t happen.  You always base your claim that it cannot happen on the fact that there has never been any evidence of it.  How do you know that?  Have you seen all of the evidence of breaching in every tank train wreck?  What is your source for saying it never happens or cannot happen?

 

 

I can't speak for Dave, but I would submit that by the time a tank car is compressed to the point of failure due to overpressure, the material making up the tank will have mechanically failed due to flexing of the metal.  Steel is only so elastic.

That is not to say that the contents won't be sprayed about when the container fails - it would be no different than squeezing a toothpaste tube with the cap off in that respect. 

LP tankers don't fail (BLEVE) directly due to overpressure.  They fail when direct flame impingement occurs on the vapor space of the tank, causing the container to fail.  The pressure in the tank then takes advantage of that single point failure and the fire that caused it to further the BLEVE.  

 

 

Just to clarify:  I referred to a tank car caught in a pileup, and subjected external squeeze that collapses its tank, thus raising its pressure high enough to cause it to “burst.”  I am not suggesting that this bursting will amount to an explosion of any consequence such as producing a destructive pressure wave, throwing shrapnel, or causing a BLEVE. 

I am only suggesting that it will be another mode of breaching.  It will open the tank wall and eject oil, and thus add more fuel for a fire.  The “bursting” will be similar to squeezing toothpaste out of the tube, as you say, in that it will be mostly hydraulic.  Although, there will be compressed air as well to the extent that the tank fill includes air space. 

So I am referring to just another breaching mode in addition to punctures, lacerations, abrasion, damaged fittings, etc.  What I believe sets this “squeeze burst” mode apart from the others is that it will be impossible to prevent it by making tank cars stronger.    

[tree68]

Euclid

I have only said that it is possible.  You seem to imply that it is not possible, since you always refute my suggestion that it is possible.  But you have never explained why it can’t happen.  You always base your claim that it cannot happen on the fact that there has never been any evidence of it.  How do you know that?  Have you seen all of the evidence of breaching in every tank train wreck?  What is your source for saying it never happens or cannot happen?

I can't speak for Dave, but I would submit that by the time a tank car is compressed to the point of failure due to overpressure, the material making up the tank will have mechanically failed due to flexing of the metal.  Steel is only so elastic.

That is not to say that the contents won't be sprayed about when the container fails - it would be no different than squeezing a toothpaste tube with the cap off in that respect. 

LP tankers don't fail (BLEVE) directly due to overpressure.  They fail when direct flame impingement occurs on the vapor space of the tank, causing the container to fail.  The pressure in the tank then takes advantage of that single point failure and the fire that caused it to further the BLEVE.  

 

[NorthWest]

For much of the British steam era, particularly before the first Grouping, each railway decided what type of brake they wanted to use. They inevitably recieved cars with the other type of brake system. While freight cars had through pipes for both systems, they typically only had one system. Some railroads fitted both air and vacuum equipment to their locomotives, but many simply ran cars with the other system in their trains without brakes. This caused handling problems with a lot of bunching and surging, though the buffers helped somewhat. As noted, the Big Four settled on vacuum brakes. BR decided on air brakes in the 1960 while most of the four-wheel freight wagons were being scrapped as highways had killed off most carload freight by this time, and the wagons had a tendency to hunt themselves off the track where CWR was introduced. Passenger stock remained mixed at least into the 1980s. I was remarking on the problems in the steam era.

[Wizlish]

Euclid

I wonder if it is caused by corrosion due to sulfuric acid in the coal.

Probably not.  There isn't any 'sulfuric acid' in the coal itself; the sulfur compounds there produce sulfur oxides when the coal is burned at elevated temperatures, and those combine with water at lower temperatures to produce the effective sulfur acids.

Much more likely that coal dust (which is carbon-bearing and potentially conductive) would cause problems on coal trains.  Even a small amount of buildup or corrosion on the mating faces of a connector could lead to arcing at 230V, and only a small amount of arcing will produce enough heat to distort most plastics suitable for making 'tough' connector bodies. 

I think Tom was onto something when he commented about the lack of a 'self cap' for disconnected FreightMate connectors exposed to the weather on cuts of cars.  My suspicion is that some combination of proper 'grease' (the dielectric formulation used for aluminum house wiring might be a good place to start!) and a dust cover, cap, or case to protect the 'mating surfaces' and conductors from dust would be desirable.  Note that in any case an 'open' connector would be exposed to the weather, it would be possible for someone to provide an appropriate cap or 'terminator' for it.

FreightMate is the AAR standard trainline connector -- can anyone quote the relevant part of the current standard that addresses this? -- and was trademarked by New York Air Brake in 2009.  There is an interesting manual (IS-230) available fromthe New York Air Brake documentation library which describes a device called a "TED" -- this supplies power to the valves on up to 25 or so connected ECP cars to allow them to be moved by a non-ECP-equipped locomotive.  This helps address the wider question of compatibility of ECP cars, or more particularly blocks of ECP-equipped cars,  in ordinary contemporary trains.

[schlimm]

NorthWest

the UK vacuum/air train brake

BR initially (as it was prior to Thatcher, then carried on by the private operators) switched over from vacuum to air brakes between 1970 and the 1990s.

[Euclid]

dehusman

 

Euclid

 One thing I would like to know more about is to what extent mid-train derailments are investigated.  I am referring to derailments not involving collisions or fatalities. 

 

 

 

NTSB investigations are based on an accident meeting certain thresholds.  It is not dependent on where in the train the derailment occurs, however since collisions usually involve engines which carry crews, that increases the chances of a collision resulting in a fatality which would trigger an NTSB investigation.

 

 

Maybe somebody here knows the extent of investigation and reconstruction that takes place with these oil train derailments, and whether the results are ever made public.  

 

 

I don't think anybody will ever investigate an accident to your satisfaction.  NTSB investigations are public record.  Railroad investigations are probably propriatary and not accessible to the public. 

 

 

 

Punctures are common.  Punctures can initiate a tearing open of the tank wall.

 

 

Punctures by definition are a tear in the tank car wall.

 

 

  I would expect that deep and sharp bending from wall impact deformation could cause the steel to bend and crack. 

 

 

They could weaken the walls and increase the chances that the steel will crack.  Remember that's "increase chances" not "will cause".

 

 

I believe that in many cases, the tanks are subjected to extreme compression that causes deep bending, and also sometimes raises the internal pressure high enough to burst the vessel. 

 

 

 

As has been said many times before, there is no evidence of this.  The cars that have burst, have been subject to heating and the increase in internal pressure due to heating can burst the cars.  There is also the possibility of heating or other agent  causing a chemical reaction that would burst a car (such as polymerization).

 

 

I would think that loaded tank cars sliding over the ballast would be quickly torn open from the intense abrasion combined with metal wall upset and gouging.  Interestingly however, in the Lynchburg wreck, those eight tank cars ahead of the pileup were dragged on their bottoms and sides for a considerable distance without apparent breaching. 

 

 

That is because your premise is flawed,  It would take dragging a car for many, many miles to wear through the steel.  That is not a failure mode.

 

 

Dave,

I see that the NTSB is investigating the Lynchburg oil train derailment that happened about a year ago.  I don’t expect too much detail.  What I am looking for is not so much as a derailment investigation, but rather, an analysis of the breaching modes of the tank cars.  I would not be surprise if that is not investigated at all. 

As I mentioned, the Lynchburg wreck did surprise me that the cars would be dragged so far without breaching.  I see that the soft ballast will conform to the tank and provide uniform support for the load.  So the abrasion will be spread out and distributed over a large area.  So I suppose a tank could be dragged through crushed rock or soil for many miles without wearing through. 

As to punctures versus tears, I would not conclude that they are the same thing, even though punctures include tears.  I was making the distinction with punctures meaning force perpendicular to the tank wall, whereas tears are made by force parallel to the tank wall. My point was that punctures can evolve into tears.  

I also said that I believe that in many cases, the tanks are subjected to extreme compression that sometimes raises the internal pressure high enough to burst the vessel.  I know that you have insisted many times that this is impossible and has never happened.  I have explained why I think it can and does happen.  Certainly tank cars are squeezed by other tank cars when piling up.  Maybe somebody can perform a calculation to see if the kinetic force of say 20 loaded tank cars, moving at say 25 mph, could collapse a tank and hydraulically burst the vessel as a consequence.  I think there would be much more than enough force to do that.  If it could, the only other ingredient would be that the tank receiving the force was locked into position.       

I have only said that it is possible.  You seem to imply that it is not possible, since you always refute my suggestion that it is possible.  But you have never explained why it can’t happen.  You always base your claim that it cannot happen on the fact that there has never been any evidence of it.  How do you know that?  Have you seen all of the evidence of breaching in every tank train wreck?  What is your source for saying it never happens or cannot happen?

[NorthWest]

Wizlish

I, personally, get somewhat nervous when a computer system has the authority to disable brake gear on individual cars, especially when (as here, if the reporting is accurate) there is an individual low-level processor system or subroutine that has the authority, and can exercise it based only on rate of perceived release or 'anomalous' condition of its car's brakes... what's to keep some sort of common-mode issue, or even some version of Stuxnet, from commanding many valves from taking such action?

Another problem with radio transmitted ECP brakes is that the cars can be hacked. Imagine someone disabeling all the brakes on an oil train on, say, Cajon Pass. 

The performance differentail is different, but if the UK vacuum/air train brake handling problems are any indication, having greatly different rates of brake application in a train cannot be a good thing.  

[Euclid]

I wonder if it is caused by corrosion due to sulfuric acid in the coal. 

[Paul of Covington]

   Looking at that slide, I don't see any protection from the elements if a car is set out for some time.   If you put a coat of grease on the contacts, that would help protect them from moisture, but it seems to me the grease would attract blowing dust.

[oltmannd]

Euclid

Don,  Okay, I see which ones they are.  I am curious about the failures.  What causes the damage?  It seems like whatever would affect one connector would affect them all except for coupling/uncoupling events.  Yet, it sounds like failures are very sporadic.  I don't know how big the problem actually is.  If the problem is common, I would expect it to get fixed quickly.  Or, is it undergoing a long process of fixing and testing that has yet to resolve the problem? 

 

What I've heard comes from revenue coal train testing.  A couple times a month, they spend a couple hours chasing down and fixing a bad connectors, even though they rarely touch them at all.

[Euclid]

Don,  Okay, I see which ones they are.  I am curious about the failures.  What causes the damage?  It seems like whatever would affect one connector would affect them all except for coupling/uncoupling events.  Yet, it sounds like failures are very sporadic.  I don't know how big the problem actually is.  If the problem is common, I would expect it to get fixed quickly.  Or, is it undergoing a long process of fixing and testing that has yet to resolve the problem? 

[BaltACD]

oltmannd

http://slideplayer.com/slide/236563/

slide 28

 

Those connectors may suffice for the Walt Disney Railroad - but not on a Class 1 in day in, day out operation through all kinds of weather.

[oltmannd]

Euclid

 

 

oltmannd

 

Paul of Covington

About ECP:  I cringe at the thought of 120, 130 or more electrical connections in a train in all extremes of weather.   MC636 says they've been in use successfully in Australia, but I wonder if the area they work in has the extremes of weather we have here.   What is the protection from moisture and dirt on the connectors if a car is set out for a while?

 

 

Anecdotally, the trouble from the electical connectors on ECP test trains and the time it takes to find and replace a bad one is still pretty significant.  Loose/burnt connectors and recepticles seem to be the biggest problem....and this is on unit trains where the connectors are generally not messed with day-to-day.

 

 

 

 

 

What is causing the loose/burnt connectors and receptacles?  What do people think the solution to the problem should be?

 

Do these connectors pull apart and separate like air hoses do as cars are uncoupled and pulled apart?  Or are the connectors made to only be separated by hand.

 

 

 

http://slideplayer.com/slide/236563/

slide 28

[Wizlish]

wanswheel

Would a non-ECP car compromise or ruin effective use of ECP?

It does, in two ways:

1) The air line in ECP is maintained at constant pressure, as a supply for charging individual reservoirs.  There is no way to drop the air line pressure to get conventional triples to open in a modulated fashion, and then pump up the air to get them to release, that coordinates at all well (except in a kind of default case) with how ECP brakes would be applied and given graduated release.

2) Once a non-ECP car is braking, its control will not respond to the electric signal being sent to any or all of the ECP modulating valves.  So I would expect that too quick a graduated release might cause run-ins or 'snatches' of draft gear against slower-releasing cars or blocks of cars.

Now, it is my understanding that at least some cars 'converted' to ECP still retain their conventional braking gear; it's just used differently.  The ECP valve attaches between the existing valve and its piping (if I understand the WABTEC slides correctly) and the emergency braking is still essentially pneumatically controlled -- the air line pressure (whether artificially maintained at full pressure or not) is dumped and the (existing) valves open to apply full emergency reservoir pressure to the cylinders.  No fancy electromagnetic proportional valves are required to do this, although I expect the faster release of line pressure through the magnet valves' actuating through service position will drop the line to emergency-application pressure toward the rear of the train marginally faster (perhaps this accounts for the 7% or so observed 'improvement' in emergency stopping distance claimed for ECP). 

Note that in case of electrical failure in a train braked this way, you would still (theoretically) have the capability of service-braking the train as well as doing the emergency stop.  It might follow that these cars could be 'conventionally' braked, in a regular train, much as if they had normal AB valves and so forth.  What does not follow (at least in the WABTEC system that follows the current standards) is the ability to run ECP cars with the full ECP control if some of the cars only have conventional pneumatic control -- and this whether or not the conventional cars have a passthrough 230V/network cable setup.

Excerpt from IEEE Spectrum (2009)

http://spectrum.ieee.org/transportation/mass-transit/stop-that-train

In the back laboratory at Wabtec’s electronics division in Germantown, a full-scale but stationary freight train with 150 empty cars is pretending to brake…

Chuck Wolf, Wabtec’s principal systems engineer, pushes his joystick. Instantly the rods in 150 brake cylinders extend outward, and a fleet of white flags glides forward in unison…

Wolf applies the brakes again, this time with the equivalent of a gentle squeeze. It’s over in 3 seconds. Then he tries a somewhat firmer application. At one point a blast of air unexpectedly explodes in the room, and a flag slides back toward the cylinder. Something has gone wrong with the brakes in Car 149, so the car’s onboard computer takes them off-line. This now registers on a screen in the locomotive, which reports that 95 percent of the brakes are working.

The 'white flags' show the extension of the air cylinders.  I am presuming that the flag 'sliding back toward the cylinder' shows the effect of the brake being disabled.  Exactly what the 'computer' does to 'take the brakes off-line' is the essential detail here -- and I don't think the reference gives us enough information to know what that is.  I would PRESUME that it is releasing the brake on that particular car by commanding a full-rate recharge from the trainline (further presuming that we have a 'dynamiter' that has to be suppressed via release, or in this case the simulation of release just on the particular car in question) and it then disables further brake action on that particular car, presumably by disabling modulation of the EC brake valve.  Note that this trick will not work if the trainline pressure has to be modulated in any substantial way, and it may not work quickly if the trainline pressure has sagged down for some reason.

A further question is the degree to which that particular car's brakes are now 'offline' with respect to further braking (or testing) and what the system, or the railroad rules, expect the crew to do about it.  It's all well and good for the system to display "95% of brakes are working" (as the article says), but what's the current rule about KNOWN disabled brakes in a train?  I, personally, get somewhat nervous when a computer system has the authority to disable brake gear on individual cars, especially when (as here, if the reporting is accurate) there is an individual low-level processor system or subroutine that has the authority, and can exercise it based only on rate of perceived release or 'anomalous' condition of its car's brakes... what's to keep some sort of common-mode issue, or even some version of Stuxnet, from commanding many valves from taking such action?

[Euclid]

oltmannd

 

Paul of Covington

About ECP:  I cringe at the thought of 120, 130 or more electrical connections in a train in all extremes of weather.   MC636 says they've been in use successfully in Australia, but I wonder if the area they work in has the extremes of weather we have here.   What is the protection from moisture and dirt on the connectors if a car is set out for a while?

 

 

Anecdotally, the trouble from the electical connectors on ECP test trains and the time it takes to find and replace a bad one is still pretty significant.  Loose/burnt connectors and recepticles seem to be the biggest problem....and this is on unit trains where the connectors are generally not messed with day-to-day.

 

 

What is causing the loose/burnt connectors and receptacles?  What do people think the solution to the problem should be?

Do these connectors pull apart and separate like air hoses do as cars are uncoupled and pulled apart?  Or are the connectors made to only be separated by hand.

 

[BaltACD]

wanswheel

Would a non-ECP car compromise or ruin effective use of ECP?

 

Excerpt from IEEE Spectrum (2009)

 

http://spectrum.ieee.org/transportation/mass-transit/stop-that-train

 

In theory, a single incompatible car could thwart an entire train’s braking system, and a single stubborn company could foil implementation across the entire network.

Details!  Details! Details!

Everyone wants to gloss over the details.

[wanswheel]

Would a non-ECP car compromise or ruin effective use of ECP?

Excerpt from IEEE Spectrum (2009)

http://spectrum.ieee.org/transportation/mass-transit/stop-that-train

In theory, a single incompatible car could thwart an entire train’s braking system, and a single stubborn company could foil implementation across the entire network.

 

[tree68]

Wiz - the discovery I spoke of would be analogous to plugging a computer into a hub and having the network recognize the computer and thus issue an IP.  Barring security considerations, any computer can join the network.

A radio based system that simply discovered all cars within range wouldn't work, for obvious reasons, as I mentioned.  Hence a system which only accepted cars already identified to the system is the only one that would work.  

The problem there would be if there was an extra car in the consist that wasn't properly identified to the system, or if a car failed to respond because of an equipment failure, or it simply wasn't there.  

The Westinghouse system doesn't care, as any traffic department person who's ever tried to find a missing car can tell you.  If it passes the usual tests, it rolls.

[Euclid]

I had not noticed what her bill says about banning the 111 cars.  But the entire fleet is not composed of 111s, as far as I know.  So is it accurate for the news headline to say she wants to take all of the crude oil cars off the tracks?

I thought the most controversial aspect of her bill was that it included an ECP brake mandate.  But the USDOT has provided that mandate without Senator Baldwin's bill. 

[Paul of Covington]

  Sorry, the devil made me do this:

   "Tammy Baldwin's bill would take ALL train cars carrying crude off the tracks"

   And one of the main points of this discussion has been keeping them on the tracks.

[zardoz]

zugmann

 We're entrusted with millions of dollars of equipment and enough chemicals to level a large town if we impropely run a train, but we can't be trusted with a switch.

What an industry.

 

Consider that some of those with authority do not necessarily have intelligence: "We need to take action now". Tammy Baldwin's bill would take ALL train cars carrying crude off the tracks":

http://fox6now.com/2015/05/27/we-need-to-take-action-now-tammy-baldwins-bill-would-take-all-train-cars-carrying-crude-off-tracks/

Of course she does not offer any alternative plan. Maybe she just wanted to hear herself preach. At least she included the obligatory picture of an explosion.

[schlimm]

Does anyone have accurate info on the use of ECP and its cousins on other railroads in the world?  For how long?  

[Wizlish]

tree68

I would opine that wire probably is not be the answer.  Two-way EOTs would not be in use today if they relied on a wire running the length of the train.

A still better example would be DPU if it required the equivalent of a multiwire MU cable run the length of the train, as in push-pull consists...

Of course, two-way EOTs aren't a very good analogy to an ECP system.  It's more practical to power an EOT from an air turbine, for example, and the consequences of LOS are much simpler and more direct than would be the case for a 'distributed' brake control system.

Optics is clearly out, for a variety of reasons, which leaves radio.

Remembering that there is a much wider constellation of approaches, both in terms of physical carrier and modulation, than simple point-to-point or broadcase 'radio' implies...

The bugaboo there will be twofold.  First will be having robust equipment that will work at five nines.

You will not get this in a practical railroad environment.  Even if it works 'in the lab' and in tests, and even on initial rollout, it's only a matter of time before the equipment starts to age, the level of support goes down, people get complacent, etc.

What needs to be 'five nines' or better isn't the equipment per se, it's the integrity of the result the system produces.  That will require some redundancy outside of common-mode failure, and the criteria I mentioned earlier (including self-healing for emergent anomalies, graceful degrade, failing safe).

I am aware it's increasingly difficult to accomplish this with deterministic systems.  There are outside-the-box answers to this that I think people like Euclid should have seen by now, especially in a world where we have eight-core telephones with GHz processor speeds.

Second will be the development of a means to make the "connection" between the locomotive and all of the cars in a secure (and robust) manner.  And I mean secure in the sense of it occurring (and continuing to occur) at five nines.  That includes being able to deal with individual unit failure, as well as tunnels and other impediments to the signal.

That's one of the two chief reasons for 'wireline' networking, along with assured 'power-over-network' at reasonable assured wattage into load.

Personally, I think the 'answer' to LOS is better passive antennas and repeaters, particularly in tunnels.  This is one of the 'killer apps' for that drone technology we were discussing a couple of months ago.   

 

Security in the form of encryption is actually easy in the digital world, although it adds a layer of cost.

That is the least of your actual security concerns.  Much more important, for example, is how you recover from something like an intentional DDoS.  Without the 'desired result' of the DDoS occurring -- which is trains either stopping dead for long periods of time, or becoming unsafe to operate.  (At least one of the logical extensions of this to PTC is being taken up in another thread as I write this...)

The 'correct' answer to this is complex, but not complicated.

For unit trains, making that connection (getting all of the units logged in) will not be a problem most of the time.  There are few changes in the consist, a topic that has been discussed here before.  For loose car railroading, it will take a whole new paradigm in consist documentation.

That's just silly (for the case where the whole consist is ECP equipped).  Look at how the 'standard' approach determines where the cars are (which WABTEC says takes 8 to 10 seconds).  If cars are removed from a dedicated unit train ... you repeat the handshake procedure.  Problem solved!.  If you switch cars in or out, you repeat the handshake procedure when the train is 'made' ... problem solved!  It's not as if there are router-table buffers or some sort of reference to the manifest order to screw things up!

Situation gets a little more interesting if you have 'compatibility'-wired cars without ECP in your consist.  I don't see this as very likely at present, but the 'solution' is little more complicated than using a TDR to determine wire lengths between handshake 'turn-ons'.  (I'd have presumed that the 'passthrough' wiring would have some sort of passive ID in it, that would identify something like UMLER ID for the car in a form the brake-system processor could read, but that's just me.)

Out in the boonies, it would be simple to just poll and see who answers.  In a yard with hundreds, or thousands of cars, such a poll would really be comical...

 Actually, not really that comical, at the speed modern networks would run even at 220MHz carrier.  And that's not the approach that would be used in a stateless wireless environment. 

 

Assume that each car that has 'wireless connectivity' also has access to a distributed network environment, and that it has an assigned ID.  An argument can be made that the system ought to 'track' all cars assigned to a particular manifest, regardless of where they happen to be at any given moment.  So if there's a break-in-two and rollaway, or a car jumps out of the train and the cars mysteriously recouple, or the wrong setout is made, the 'default' operation of the system will catch it in ways that make recovery simple for normal railroading humans.  Making a Chinese puzzle out of data protocols is well and good for security ... or for IT departments that want to prove how indispensable they are (and now for 'business logic' or 'e-commerce synergy' or whatever).  But it has no particular place in safety-critical systems for railroading.

 

Going to be interesting to see how the various pieces of infrastructure get implemented, including the mistakes.  I am presently hoping for example that the knee-jerk reaction against 'wedge-in-the-door' progressive mandating of ECP does not result in proactive crippling of other parts of the infrastructure that would best implement the benefits of ECP in a practical sense.

[Wizlish]

Euclid

I have read that the electrical connectors have been a weak area in ECP. It would not surprise me if they had been mechanically under-designed. The larger and more robust they are, the harder it would be for a person to plug and unplug them. That limit implies a two-stage action, with the second stage applying the engagement pressure by means of a lever, or something on that order.

It is not exactly as if people since the days before Frank Sprague have been ignorant about connecting electrical lines between cars.  There is enough in the published literature (and patent literature) to get you a leg up on practical design without floating a few chestnuts out as if they were novel insights.

The connector between cars should be designed so it holds together, with high integrity and weather/dirt immunity, in all situations where the air hose holds together.  But it should also release, cleanly and without damage, in situations where the air hose is intended to part.  A system that locks with any kind of lever fails this elementary criterion, let alone that it is rather dumb for a number of other reasons (for example, unless explicitly designed to eject dirt or contaminants, the lever will be prone to put mechanical advantage on wedging insulating dirt into contacts or jamming or distorting the connector body).

I was impressed that WABTEC kept the part of the lead with the connector strictly separate (and presumably relatively cheap and perhaps easy to kludge in the field) so that when, not if, there is a pullapart the actual wiring on the car, or the pins in the car's receptacle, won't be damaged.  Your crew would carry a few 'ends' and whatever tools would assist with changing out the damaged pieces ... easily even at one-dark-thirty in rain and mud, if the design engineers have done their thinking right.

You might want to ask the contact person from that WABTEC presentation to send you a description of the development process that produced the FreightMate connector (of which they seem to be so proud).  I suspect there will be some highly interesting optimization decisions -- and perhaps even some design 'misconceptions' -- in their methodology and development process.  Whenever the time comes for a 'bold new theory', it's wise to determine exactly what the old theories have tried, and why they may have rejected things they tried, before jumping in and proposing stuff.

Whatever the solution, I doubt that connector problems are a showstopper. ECP brakes are not an unproven theory. So I would like to know if connector problems plague ECP applications in Australia, South Africa, Brazil, and Canada.

You've already heard from people saying there are problems.  It would be interesting to see more detailed statistics; I'm not sure 'plague' will be the operative word for fixed-consist or unit trains.  The thing of most interest to me would be evidence of common-mode failures of some part(s) of the systems in use, or adhering to standards, that would indicate the need for revision or development of practical alternatives.

[Euclid]

I have read that the electrical connectors have been a weak area in ECP.  It would not surprise me if they had been mechanically under-designed.  The larger and more robust they are, the harder it would be for a person to plug and unplug them.  That limit implies a two-stage action, with the second stage applying the engagement pressure by means of a lever, or something on that order.  Whatever the solution, I doubt that connector problems are a showstopper.  ECP brakes are not an unproven theory.  So I would like to know if connector problems plague ECP applications in Australia, South Africa, Brazil, and Canada.    

[Wizlish]

oltmannd

Anecdotally, the trouble from the electrical connectors on ECP test trains and the time it takes to find and replace a bad one is still pretty significant. Loose/burnt connectors and receptacles seem to be the biggest problem....and this is on unit trains where the connectors are generally not messed with day-to-day.

Reading between the lines in the WABTEC material, you can see that failures in the actual intercar connections (the by-now-famous "FreightMate[tm]" connectors) are expected, and their system has been explicitly designed to allow just the 'ends' to be swapped out quickly.  Presumably a crew would carry a number of the little 'ends', a can of dielectric grease, and some of the little hangers and clips that hold the wire up between cars.

If you look at how the 'handshake' is established among the cars (sequentially, with what I consider a potential point-of-failure with the soft switches in the network equipment, another matter for discussion) it will give you a definitive indication of where a 'failure to communicate' has occurred in the train.  A road failure would require only a repetition of the 'handshake test' (said by them to involve about 8 to 10 seconds for the whole consist) to give an indication of the 'first' break, and when that is fixed, 8 to 10 seconds max for the next one if present.

I would also presume there is appropriate BITE in each car that 'reports' to the head end on electronic or electrical failures on a given car.

There has been an interesting shift in quality assurance since the experience with Internet Protocol, away from failure prevention to failure remediation.  It's assumed that no practical system will have 'five-nines' or 'six-sigma' MTTF or whatever (although of course engineers will try to reduce this 'best they can') -- the emphasis is on DETECTING and then WORKING AROUND failures when, not if, they occur.  That was the premise of a working 'internet' since the days of AlohaNet, and I would submit it is just as appropriate to handling critical safety communications in distributed braking.

[tree68]

oltmannd

The catch-22 is that if you don't keep testing and developing, you'll never get a "finished product". But, the testing is causing all sorts of heartache getting trains out on the road, so how much can you afford to test?

The term "diminishing returns" comes to mind.  

I would opine that wire probably is not be the answer.  Two-way EOTs would not be in use today if they relied on a wire running the length of the train.

Optics is clearly out, for a variety of reasons, which leaves radio.

The bugaboo there will be twofold.  First will be having robust equipment that will work at five nines.

Second will be the development of a means to make the "connection" between the locomotive and all of the cars in a secure (and robust) manner.  And I mean secure in the sense of it occuring (and continuing to occur) at five nines.  That includes being able to deal with individual unit failure, as well as tunnels and other impediments to the signal.

Security in the form of encryption is actually easy in the digital world, although it adds a layer of cost.

For unit trains, making that connection (getting all of the units logged in) will not be a problem most of the time.  There are few changes in the consist, a topic that has been discussed here before.  For loose car railroading, it will take a whole new paradigm in consist documentation.  Out in the boonies, it would be simple to just poll and see who answers.  In a yard with hundreds, or thousands of cars, such a poll would really be comical...

[oltmannd]

Paul of Covington

About ECP:  I cringe at the thought of 120, 130 or more electrical connections in a train in all extremes of weather.   MC636 says they've been in use successfully in Australia, but I wonder if the area they work in has the extremes of weather we have here.   What is the protection from moisture and dirt on the connectors if a car is set out for a while?

Anecdotally, the trouble from the electical connectors on ECP test trains and the time it takes to find and replace a bad one is still pretty significant.  Loose/burnt connectors and recepticles seem to be the biggest problem....and this is on unit trains where the connectors are generally not messed with day-to-day.

The catch-22 is that if you don't keep testing and developing, you'll never get a "finished product". But, the testing is causing all sorts of heartache getting trains out on the road, so how much can you afford to test?

[dehusman]

Euclid

 One thing I would like to know more about is to what extent mid-train derailments are investigated.  I am referring to derailments not involving collisions or fatalities. 

NTSB investigations are based on an accident meeting certain thresholds.  It is not dependent on where in the train the derailment occurs, however since collisions usually involve engines which carry crews, that increases the chances of a collision resulting in a fatality which would trigger an NTSB investigation.

 

Maybe somebody here knows the extent of investigation and reconstruction that takes place with these oil train derailments, and whether the results are ever made public.  

 

I don't think anybody will ever investigate an accident to your satisfaction.  NTSB investigations are public record.  Railroad investigations are probably propriatary and not accessible to the public. 

 

 

Punctures are common.  Punctures can initiate a tearing open of the tank wall.

Punctures by definition are a tear in the tank car wall.

 

  I would expect that deep and sharp bending from wall impact deformation could cause the steel to bend and crack. 

They could weaken the walls and increase the chances that the steel will crack.  Remember that's "increase chances" not "will cause".

 

I believe that in many cases, the tanks are subjected to extreme compression that causes deep bending, and also sometimes raises the internal pressure high enough to burst the vessel. 

 

As has been said many times before, there is no evidence of this.  The cars that have burst, have been subject to heating and the increase in internal pressure due to heating can burst the cars.  There is also the possibility of heating or other agent  causing a chemical reaction that would burst a car (such as polymerization).

 

I would think that loaded tank cars sliding over the ballast would be quickly torn open from the intense abrasion combined with metal wall upset and gouging.  Interestingly however, in the Lynchburg wreck, those eight tank cars ahead of the pileup were dragged on their bottoms and sides for a considerable distance without apparent breaching. 

That is because your premise is flawed,  It would take dragging a car for many, many miles to wear through the steel.  That is not a failure mode.

 

[MidlandMike]

Euclid

...

I would think that loaded tank cars sliding over the ballast would be quickly torn open from the intense abrasion combined with metal wall upset and gouging.  Interestingly however, in the Lynchburg wreck, those eight tank cars ahead of the pileup were dragged on their bottoms and sides for a considerable distance without apparent breaching.  They shed their trucks, and became a chain of cylinders plowing cylindrical furrows through the ballast, while demolishing track ties and rails.

 

 

I would think you could drag a 1/2" wall steel tank thru limestone ballast all day, and would only get a polish.  Granite and basalt ballast are more abrasive, but would not do much damage in the short distance a derailed car would slide.  Those valve fittings on the other hand could be a different story.