There is at present no better system for APPLYING the brakes on trains than compressed air. ECP, which has a documented history that goes back before Westinghouse invented the triple valve, simply uses an electrically controlled valve to control the airflow to and from the brake cylinder. This allows train brakes to be applied and released like the independent brake on a locomotive, with the proportional (or 'graduated') release being a Big Thing.
The problem is that the way any current system of ECP uses the brake trainline is different from the way the huge mass of existing air brake equipment does. ECP uses the trainline only as a source of 'recharge' air, so it is kept at or near what main-reservoir pressure is as much of the time as possible. Air brakes with triples, however, use lower pressures as control signals (in addition to sonic pressure pulses sent in the compressed air in the line) and therefore cannot work -- or be adapted to work -- on a constant pressure supply. (There are some Mickey Mouse ways that you could set valves up to be controlled with coded pressure pulses, but they just aren't safe in general practice, for ways that most of you can easily figure out.)
The approaches I see being followed 'at present' involve an installation of ECP valves 'piggybacked' onto conventional triples, in such a way that a car can be 'converted' from one method of braking to the other if necessary. (Presumably this would be done via good procedure, with technical safeguards against wrong setting and tampering, etc., but we won't glaze eyes with that now.)
It is possible to put 'through connections' in cars (analogous to the through-piping of an air brake line in a non-power-braked car in the years air brakes were being adopted) so that cuts of ECP brakes can be controlled by an ECP-equipped locomotive 'separate' from what the regular trainline pressure is doing. If I am not mistaken, the systems that were tried with this are 'two-pipe' systems, where the supply air and the 'control' line are separate, although both presumably charged using the same compressor equipment in the consist.
I'd look for 'convertible' consists to appear in unit trains first, perhaps with the triples being taken out once there is no longer a perceived need to run any cut of cars from one of those trains in a 'conventional' consist, e.g. if the ECP-equipped cars were bad-ordered or wrecked or being sent to different locations for use. I think that even with the 'costed-down' figures for the added ECP functionality, the price tag for converting even the normal cars that run in particular 'lanes' would be relatively enormous, and especially unlikely in an industry while demand for most of the 'unit' traffic that most benefits from ECP is observed to be declining. That despite the multiple and real advantages, both the ones that ECP has 'always' had, and the newer ones that good computer or PLC control and wireless enablement can provide.
Electrons travel at 186,000 miles per second and are reluctant to slow down.
We now return you to your regular programming.
Norm
I haven't gone back to check and don't intend to, but I got the impression that in previous discussions about ECP, the pros on this forum were pretty cool to the need for it. For one thing, they now spend considerable time hooking up and checking the air brakes when making up a train, and with ECP there is the time added for connecting and troubleshooting the electrical part.
Personally, I spent years maintaining and troubleshooting electronic equipment and was a boat owner for many years, and I cringe when I think of mixing electricals with moisture. My boat had practically no electronic gadgets.
_____________
"A stranger's just a friend you ain't met yet." --- Dave Gardner
Norm48327 Electrons travel at 186,000 miles per second and are reluctant to slow down. We now return you to your regular programming.
However those electrons need good connections to move from vehicle to vehicle to get to the end of their intended journey - in the rail enviornment, good connections can be difficult to sustain.
Never too old to have a happy childhood!
Wizlish There is at present no better system for APPLYING the brakes on trains than compressed air. ECP, which has a documented history that goes back before Westinghouse invented the triple valve, simply uses an electrically controlled valve to control the airflow to and from the brake cylinder. This allows train brakes to be applied and released like the independent brake on a locomotive, with the proportional (or 'graduated') release being a Big Thing. The problem is that the way any current system of ECP uses the brake trainline is different from the way the huge mass of existing air brake equipment does. ECP uses the trainline only as a source of 'recharge' air, so it is kept at or near what main-reservoir pressure is as much of the time as possible. Air brakes with triples, however, use lower pressures as control signals (in addition to sonic pressure pulses sent in the compressed air in the line) and therefore cannot work -- or be adapted to work -- on a constant pressure supply. (There are some Mickey Mouse ways that you could set valves up to be controlled with coded pressure pulses, but they just aren't safe in general practice, for ways that most of you can easily figure out.) The approaches I see being followed 'at present' involve an installation of ECP valves 'piggybacked' onto conventional triples, in such a way that a car can be 'converted' from one method of braking to the other if necessary. (Presumably this would be done via good procedure, with technical safeguards against wrong setting and tampering, etc., but we won't glaze eyes with that now.) It is possible to put 'through connections' in cars (analogous to the through-piping of an air brake line in a non-power-braked car in the years air brakes were being adopted) so that cuts of ECP brakes can be controlled by an ECP-equipped locomotive 'separate' from what the regular trainline pressure is doing. If I am not mistaken, the systems that were tried with this are 'two-pipe' systems, where the supply air and the 'control' line are separate, although both presumably charged using the same compressor equipment in the consist. I'd look for 'convertible' consists to appear in unit trains first, perhaps with the triples being taken out once there is no longer a perceived need to run any cut of cars from one of those trains in a 'conventional' consist, e.g. if the ECP-equipped cars were bad-ordered or wrecked or being sent to different locations for use. I think that even with the 'costed-down' figures for the added ECP functionality, the price tag for converting even the normal cars that run in particular 'lanes' would be relatively enormous, and especially unlikely in an industry while demand for most of the 'unit' traffic that most benefits from ECP is observed to be declining. That despite the multiple and real advantages, both the ones that ECP has 'always' had, and the newer ones that good computer or PLC control and wireless enablement can provide.
NS and CP have both been testing unit coal trainsets with ECP for several years now, another thing to watch for is modifying locomotives so they have the ability to control the ECP brakes. NS seems to have been ordering all their new power like this, those units can be identified by the prescence of a couple large electrical plugs and heavy-duty cables mounted on either side of the drawbar.
Greetings from Alberta
-an Articulate Malcontent
A month or two back, I had one of the UP's ECP equipped engines in the lead. In conventional operation, though. I haven't seen much about in company related reading material. They're probably more concerned right now with PTC.
Jeff
In that you are incorrect: the speed of the electrons in a copper wire is much slower; what you are describing is the reaction time you see at the end of the wire (somewhere around 2/3 of the speed of light: 124'000 miles per second or 2*10^8 m/s).
Similar to a tube filled with little balls: the ball which "feels" the actual pressure change travels with a relatively slow speed, but the reaction on the end of the tube is much faster (if you got a incompressable medium, unlike gases).
Please cut me some slack with my english, this is not my native language. ;)
SD70M-2Dude NS and CP have both been testing unit coal trainsets with ECP for several years now, another thing to watch for is modifying locomotives so they have the ability to control the ECP brakes. NS seems to have been ordering all their new power like this, those units can be identified by the prescence of a couple large electrical plugs and heavy-duty cables mounted on either side of the drawbar.
As I've posted elsewhere ECP is in extensive use in Australia in the heaviest duty unit train traffic.
In the Hunter Valley in NSW, two major operators run ECP coal trains exclusively, Aurizon and Glencore (whose trains are operated by the British Freightliner company, a subsidiary of Genessee and Wyoming). The biggest operator, Pacific National have converted about half their fleet (actually, that half was purchased new during recent expansion).
In Central Queensland where Pacific National were the newcomer, their entire coal fleet has ECP braking and Aurizon have mainly conventional brakes.
ECP trains can run faster through yards since they can reliably stop more quickly and have fewer "flat wheels". I'd expect that wheel life and brake block life would be better.
In Australia, nobody is forcing, or even asking these operators to use ECP. They have purchased ECP trains because it is cost effective to do so.
M636C
M636C SD70M-2Dude NS and CP have both been testing unit coal trainsets with ECP for several years now, another thing to watch for is modifying locomotives so they have the ability to control the ECP brakes. NS seems to have been ordering all their new power like this, those units can be identified by the prescence of a couple large electrical plugs and heavy-duty cables mounted on either side of the drawbar. As I've posted elsewhere ECP is in extensive use in Australia in the heaviest duty unit train traffic. In the Hunter Valley in NSW, two major operators run ECP coal trains exclusively, Aurizon and Glencore (whose trains are operated by the British Freightliner company, a subsidiary of Genessee and Wyoming). The biggest operator, Pacific National have converted about half their fleet (actually, that half was purchased new during recent expansion). In Central Queensland where Pacific National were the newcomer, their entire coal fleet has ECP braking and Aurizon have mainly conventional brakes. ECP trains can run faster through yards since they can reliably stop more quickly and have fewer "flat wheels". I'd expect that wheel life and brake block life would be better. In Australia, nobody is forcing, or even asking these operators to use ECP. They have purchased ECP trains because it is cost effective to do so. M636C
The uses you describe sound like captive service enviornments - not subject the the loose car railroading that takes place in the US.
WizlishECP, which has a documented history that goes back before Westinghouse invented the triple valve,
Let's see the documenatation. Electronics in use before 1868? Really?
C&NW, CA&E, MILW, CGW and IC fan
M636CECP trains can run faster through yards...
Finally, a cure for long terminal dwell times! Whodathunk?
Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it...
Wizlish There is at present no better system for APPLYING the brakes on trains than compressed air. ECP, which has a documented history that goes back before Westinghouse invented the triple valve, simply uses an electrically controlled valve to control the airflow to and from the brake cylinder. This allows train brakes to be applied and released like the independent brake on a locomotive, with the proportional (or 'graduated') release being a Big Thing.
Interesting, can the ECP-equipped cars be mixed with conventional ones in a train, or are they not interoperable?
And even if ECP can be made interoperable with conventional air brakes there will still be a big obstacle to its adoption over here: the Class I's love of the status quo and resistance to change of any kind.
schlimm Wizlish ECP, which has a documented history that goes back before Westinghouse invented the triple valve, Let's see the documenatation. Electronics in use before 1868? Really?
Wizlish ECP, which has a documented history that goes back before Westinghouse invented the triple valve,
Note I did not say 'straight air', I said 'triple valve'. You will find that the Westinghouse 'fast acting' brake is more modern; I recall the 50-car testing being in 1887. This is the "safe" system that applies the brakes at full pressure when the trainline pressure falls for any reason, and it is of course a much more significant 'innovation' than just the use of compressed air to apply shoes to wheels.
Evidence of the use of a magnet valve to apply 'straight air' brakes is found in the early 1870s in Frank Sprague's records, and there are early systems of ATC (one by Robinson, if I'm not mistaken) that use electricity to apply the train brake. This is no different in principle from the use of electropneumatic braking on some prewar passenger streamliners ... where full interoperability with 'ordinary' equipment was not expected. Yes, the practicality of many of these approaches to give true 'proportionality' would involve problems, perhaps involving the use of mechanical devices like dashpots or control orifices, but the general desire to valve air into and out of brake cylinders throughout a train 'as desired', with very little effective control latency, was there from the beginning.
The early history of ATC systems is interesting precisely because it both predates and intimately involves the use of actual 'electronics' (by which I mean specifically the use of thermionic devices, or the practical utilization of the 'Edison Effect') and not just relay logic or other electric actuation. Reading between the lines of the Esch Act text, quite a bit of the expected innovation coming from competition to build 'mandated' ATC devices was expected to advance the electrical and what we now call 'electronic' state of the art. It apparently was doing so, in spades, by 1928 when the ICC 'de-emphasized' ATC deployment in favor of ... better attention to grade-crossing problems.
I think we have been over this ground again and again and again. The AAR (and many in the industry) oppose the MANDATE to impose ECP, in part because they believe that any instantiation (say, the one restricted to oil trains) will begin to metastasize as so many government mandates do ... Federal individual income tax, anyone? ... until it comes to apply expensively (and fundamentally non-interworkably) across the general connected network.
Note that 'the industry' is not arguing there are no benefits to ECP -- as repeatedly pointed out in other threads, private operators have rushed to embrace ECP where the real-world benefits justify the cost. That is by almost any sensible measure of cost-effectiveness not the case for ECP applied to all the rolling stock running in North America.
One of the things that got the AAR so active was the part of proposed rulemaking that included PIH cars in the 'mandate' along with HHFT consists. Since it is very, very unlikely that any railroad will be running block trains that are exclusively hazmat (just THINK of the Web sites that would pop up if they did, c ompletely aside from scheduling and capacity concerns) this constituted more or less exactly the 'creeping application' that industry sources feared the Government would try imposing.
I doubt anyone in the industry would say that ECP represents a much better way to run trains, even with the higher inspection and maintenance requirements it would impose. (In part the technology has become much more effective in the past decade or so, with improvements in materials, batteries, and logic controls, and I think that trend will continue.) The objection is twofold: to the overall cost of converting substantial parts of the overall fleet, and the difficulties inherent in 'interworking' converted with conventional consists. I now see the latter concern being somewhat addressed. Even a best-case approximation of the former, however, will involve literally trillions of dollars -- in the absence of even a hint of government subsidy or full tax deductibility/setaside for it. Under these conditions you shouldn't be surprised to see industry sources claiming any and all excuses to avoid it...
It's a bit like emergency brakes that make trains 'stop short' at crossings. There is technology that could do this, and we've discussed it in a couple of fairly long threads. Problem is that some of the problems, including quite real aspects of quite real legal liability, are worse than the 'cure'. Do we see any industry organization dumb enough to say 'well, we could do this but it's too much liability risk for our cost/benefit ratio?' No, it's better to stick with 'it takes a mile to stop reliably and that's what it is.'
WizlishIt's a bit like emergency brakes that make trains 'stop short' at crossings. There is technology that could do this, and we've discussed it in a couple of fairly long threads.
I don't recall anything like that ever being discussed here. How would this be accomplished? Under what terms would "stopping short" occur?
SD70M-2Dude M636C SD70M-2Dude NS and CP have both been testing unit coal trainsets with ECP for several years now, another thing to watch for is modifying locomotives so they have the ability to control the ECP brakes. NS seems to have been ordering all their new power like this, those units can be identified by the prescence of a couple large electrical plugs and heavy-duty cables mounted on either side of the drawbar. As I've posted elsewhere ECP is in extensive use in Australia in the heaviest duty unit train traffic. In the Hunter Valley in NSW, two major operators run ECP coal trains exclusively, Aurizon and Glencore (whose trains are operated by the British Freightliner company, a subsidiary of Genessee and Wyoming). The biggest operator, Pacific National have converted about half their fleet (actually, that half was purchased new during recent expansion). In Central Queensland where Pacific National were the newcomer, their entire coal fleet has ECP braking and Aurizon have mainly conventional brakes. ECP trains can run faster through yards since they can reliably stop more quickly and have fewer "flat wheels". I'd expect that wheel life and brake block life would be better. In Australia, nobody is forcing, or even asking these operators to use ECP. They have purchased ECP trains because it is cost effective to do so. M636C Interesting, can the ECP-equipped cars be mixed with conventional ones in a train, or are they not interoperable? And even if ECP can be made interoperable with conventional air brakes there will still be a big obstacle to its adoption over here: the Class I's love of the status quo and resistance to change of any kind.
From my reading the electronic component of an ECP system is in addition to the standard air brake operating mode; In failure mode the air brakes can respond conventionally. So you can couple ECP equipped cars to non-ECP equipped and they will operate in conventional mode but the ECP electronics will not function.
The Electronics only work if the whole train is so equipped (keep in mind that this is not a wireless system and data must be transmitted from car to car by cables) which is why the current applications are in Unit Train service........
"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock
Euclid Wizlish It's a bit like emergency brakes that make trains 'stop short' at crossings. There is technology that could do this, and we've discussed it in a couple of fairly long threads. I don't recall anything like that ever being discussed here. How would this be accomplished? Under what terms would "stopping short" occur?
Wizlish It's a bit like emergency brakes that make trains 'stop short' at crossings. There is technology that could do this, and we've discussed it in a couple of fairly long threads.
Dave Klepper, I think, started a thread on electromagnetic track brakes, in which I think you participated. Interestingly enough, erikem did an engineer's analysis on the requirements to actually make such a thing work at full scale and concluded it could be made to function.
The basic idea (correct me anyone if this is wrong) is to provide an electromagnet of appropriate field strength and characteristics that 'rides' along the railhead, with enough cross-sectional area to produce both 'clamping' friction and eddy current induction in the rail steel. When a high current is applied through this magnet it produces a strong retarding force, independent of any braking being applied to the wheels, and under some circumstances it can exert a restoring force to keep a carbody (or truck frame, perhaps) in line with the rails. There is a limit as to energy dissipation (in part set, I think, by the Curie point of the railhead) and there are some potential problems with rail lifting or activation on curves or crossovers, and of course with dramatic problems in train handling if there is any differential slack or disproportionate braking level in different parts of the train.
A version of this is and was applied historically to streetcars, where it has I believe been demonstrated to work quite well, at the (unexpected to me) cost of increasing rail corrugation when used more than intermittently.
Apparently modern Li-ion battery tech has gotten to the point that it can store enough energy to brake a given loaded car down to a reasonable speed in a respectably short time ... once. It may not matter if parts of the system, or indeed parts of the track, require even expensive repairs when the emergency track brake is 'fired'. The more important consideration -- which as I mentioned would be difficult if not impossible to substantiate -- is whether the system introduces more danger or risk than it relieves.
Westinghouse did invent the triple valve air brake in 1887. Even so, to suggest anything using electronic brake systems before that time is not supported by facts.
The Southern Region of BR introduced the electro-pneumatic system for suburban passenger service in Britain in 1950. Still electric, not electronic.
ECP came later. http://www.railway-technical.com/brake3.shtml
Electric / electrical systems use electricity to transmit and manipulate power.
Electronic systems use electricity to transmit and manipulate information.
schlimmElectric / electrical systems use electricity to transmit and manipulate power. Electronic systems use electricity to transmit and manipulate information.
Your definition is oversimplified, and your understanding of the difference shows a marked ignorance of this field.
Strictly electric devices can, of course, be proportional: the existence of rheostats and potentiometers will establish this very simply. Relay logic, using nothing but magnets and coils, is used regularly to transmit 'information' such as MU signals. The eleectropneumatic systems in the Thirties (well-established long before that whatever-it-is reference you cobbled up for Great Britain) were proportionally controlled by mechanical devices (Decelakron and Decelostat being two makes).
Electronics, meanwhile, is defined as the use of electron currents (hence the name, capiscs?) for control purposes -- as mentioned, in thermionic devices or their more recent solid-state analogues. There is a well-defined field of 'power electronics' which your definition only covers with the most tortured of logical interpretation: the purpose of a thyristor, for example, is to control power, often in the form of a simple output voltage.
Note that I have edited the original post to reflect that I should not have used the abbreviation "ECP" to refer to earlier systems if that 'E' represents 'electronics'. While there is justification for observing the idea behind electronics as early as 1881, practical use of the effect did not take place until after 1900, and of course was not used by any method of braking control 'invented' or proposed prior to then. To that extent, schlimm is correct.
Wizlish schlimm Electric / electrical systems use electricity to transmit and manipulate power. Electronic systems use electricity to transmit and manipulate information. Your definition is oversimplified, and your understanding of the difference shows a marked ignorance of this field. Strictly electric devices can, of course, be proportional: the existence of rheostats and potentiometers will establish this very simply. Relay logic, using nothing but magnets and coils, is used regularly to transmit 'information' such as MU signals. The eleectropneumatic systems in the Thirties (well-established long before that whatever-it-is reference you cobbled up for Great Britain) were proportionally controlled by mechanical devices (Decelakron and Decelostat being two makes). Electronics, meanwhile, is defined as the use of electron currents (hence the name, capiscs?) for control purposes -- as mentioned, in thermionic devices or their more recent solid-state analogues. There is a well-defined field of 'power electronics' which your definition only covers with the most tortured of logical interpretation: the purpose of a thyristor, for example, is to control power, often in the form of a simple output voltage. It's always fun when academics out of their field try to 'put one over' on the ordinary folks, but in this case your qualifications appear to be coming up distinctly short.
schlimm Electric / electrical systems use electricity to transmit and manipulate power. Electronic systems use electricity to transmit and manipulate information.
It's always fun when academics out of their field try to 'put one over' on the ordinary folks, but in this case your qualifications appear to be coming up distinctly short.
I was keeping it simple. You attempted to obscure your inaccurate statement about electronics with a bunch of irrelevant puff. And then you compound it by character attacks and condescending sneers. Yes, I am an academic, not a high school kid who tries to impress one and all. I have never pretended to be an expert on this topic , and have no need to. But I can read.
Again, returning to the point here, to state that electronic brakes were used as far back as the triple valve is an obvious falsehood.
schlimm Wizlish schlimm Your definition is oversimplified, and your understanding of the difference shows a marked ignorance of this field. Strictly electric devices can, of course, be proportional: the existence of rheostats and potentiometers will establish this very simply. Relay logic, using nothing but magnets and coils, is used regularly to transmit 'information' such as MU signals. The eleectropneumatic systems in the Thirties (well-established long before that whatever-it-is reference you cobbled up for Great Britain) were proportionally controlled by mechanical devices (Decelakron and Decelostat being two makes). Electronics, meanwhile, is defined as the use of electron currents (hence the name, capiscs?) for control purposes -- as mentioned, in thermionic devices or their more recent solid-state analogues. There is a well-defined field of 'power electronics' which your definition only covers with the most tortured of logical interpretation: the purpose of a thyristor, for example, is to control power, often in the form of a simple output voltage. It's always fun when academics out of their field try to 'put one over' on the ordinary folks, but in this case your qualifications appear to be coming up distinctly short. I was keeping it simple. You attempted to obscure your inaccurate statement about electronics with a bunch of irrelevant puff. And then you compound it by character attacks and condescending sneers. Yes, I am an academic, not a high school kid who tries to impress one and all. I have never pretended to be an expert on this topic , and have no need to. But I can read. Again, returning to the point here, to state that electronic brakes were used as far back as the triple valve is an obvious falsehood.
Wizlish schlimm Your definition is oversimplified, and your understanding of the difference shows a marked ignorance of this field. Strictly electric devices can, of course, be proportional: the existence of rheostats and potentiometers will establish this very simply. Relay logic, using nothing but magnets and coils, is used regularly to transmit 'information' such as MU signals. The eleectropneumatic systems in the Thirties (well-established long before that whatever-it-is reference you cobbled up for Great Britain) were proportionally controlled by mechanical devices (Decelakron and Decelostat being two makes). Electronics, meanwhile, is defined as the use of electron currents (hence the name, capiscs?) for control purposes -- as mentioned, in thermionic devices or their more recent solid-state analogues. There is a well-defined field of 'power electronics' which your definition only covers with the most tortured of logical interpretation: the purpose of a thyristor, for example, is to control power, often in the form of a simple output voltage. It's always fun when academics out of their field try to 'put one over' on the ordinary folks, but in this case your qualifications appear to be coming up distinctly short.
schlimm
How far has your urinary competition line moved from the toilet boys?
I I detect nits being picked. Lighten up boys.
No,no...let them go at it!
Its like Snidely Whiplash vs Boris Badenov.....
23 17 46 11
Electroliner 1935 I I detect nits being picked.
I I detect nits being picked.
Picking nits is so much fun
As for "electric" vs "elecronic", my B.S. degree from UC Berkeley was for Electrical Engineering and Computer Science, though very few of the EECS majors at Cal did much with either electric power systems or electrical machinery.
To add a bit more fuel to the fire, an EE professor at Stanford, Tom Lee, stated that the field of electrical/electronic engineering got started from a gigantic screw up with the early trans-atlantic telegraph cables. Note there were no active devices (vacuum tubes, transistors, thyristors, etc) at that time. The chief focus of study in that work was the propagation of the signal through the transmission - which is a subject that still catches a lot of EE's unaware.
As for electrically controlled braking, one of Westinghouse's chief motivation for improving the triple valve was that he didn't want to use electrical control of the air brakes.
Electropneumatic braking for passenger cars was available in time for use on the early streamliners (mid to late thirties) and many of those installations had some form of anti-lock braking.
- Erik
Instead of arguing endlessly about :"electric" vs. "electronic" it would make more sense for people to actually find out something about ECP braking.
Here is a link to a good article about ECP braking—and yes, it is an electronically controlled system: http://www.railway-technical.com/brake3.shtml
Kurt Hayek
sandiegoInstead of arguing endlessly about :"electric" vs. "electronic" it would make more sense for people to actually find out something about ECP braking.
But..... But..... But..... Some posters love to argue for the sake of argument alone, never mind accuracy.
sandiego Instead of arguing endlessly about :"electric" vs. "electronic" it would make more sense for people to actually find out something about ECP braking. Here is a link to a good article about ECP braking—and yes, it is an electronically controlled system: http://www.railway-technical.com/brake3.shtml Kurt Hayek
Thank you. That was the article I read. I should have linked it. Sorry if calling somone out on their preposterous statement ["There is at present no better system for APPLYING the brakes on trains than compressed air. ECP, which has a documented history that goes back before Westinghouse invented the triple valve, simply uses an electrically controlled valve to control the airflow to and from the brake cylinder"] is so irritating to certain posters.
schlimmAgain, returning to the point here, to state that electronic brakes were used as far back as the triple valve is an obvious falsehood.
Yes, it is, and I have tried to correct that impression by editing the previous posts.
The point I wanted to establish, and missed, was that electrically-controlled proportional operation of brakes was developed prior to the invention of the triple valve. erikem has, I think, corroborated this. I do not think we need to proceed further with a pissing contest of any kind.
As it turns out, I have been informed that the most likely 'formal' distinction between 'electric' and 'electronic' appears to be a bit different. "Electronics" is the discipline formerly known as "radio engineering", and when the American organizations for radio engineering and electrical engineering merged, the current name (IEEE) was chosen to reflect this.
George O. Smith had an interesting 'take' on the legal definition of information vs. power transfer in one of his "Venus Equilateral" stories ... where he brought up, btw, the functional overlap in the applicable technologies (albeit for somewhat melodramatic plot purposes!)
EuclidI am generally interested in ECP brakes, but the part I currently find most interesting is the fact that they will be put into use in the U.S. That will be only for oil trains, but still, it seems like really big news. That is a MAJOR change in the railroad industry. And yet strangely, I find no news update on the plan or conversion underway since it was announced last spring.
Some of this involves the ongoing objection to 'mandated' ECP in general that we've been commenting on. I suspect that as long as ECP is being resisted in general, the cost of its actual application to HHFT consists will be avoided or at least 'put off a while'.
On the other hand, there are coherent efforts to provide ECP installations on HHFT or other consists, with high assurance and within an appropriate timeframe to meet the mandate if it stands. I know of at least two. Do not expect details on any public forum.
I would like to see ECP adopted for certain traffic; indeed, I'd like to see some system of it adopted for general train handling. But that decision does come with substantial financial 'consequences', and you can readily observe that, for example, any decision by NS or CSX to start spending money on anything more than general feasibility studies would be used by Ackman and Co. or a group like the Children's Fund as a substantial proof of 'waste of shareholder value'. Both in the short run that so many financial 'analysts' ruin their analysis by emphasizing, and in the potential long run if ECP use doesn't become prevalent 'enough' or the technologies they adopt become obsolescent ... as so many technologies in ECP over the years have indeed become.
EuclidIf the 2021 deadline arrives unmet, will the railroads threaten to stop hauling oil by rail because it would be illegal after the deadline? How would Congress and the FRA react to a shutdown of just oil trains? I suspect the answers to these questions will be greatly affected by the perception of oil train safety as operating effects unfold over the next five years.
With the number of oil trains reduced dramatically the past year or so, the task to convert them to ECP isn't anywhere as gargantuan as it once was. So the issue is nowhere near as MAJOR unless oil prices shoot back up.
It's been fun. But it isn't much fun anymore. Signing off for now.
The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.t fun any
Wizlish Euclid I am generally interested in ECP brakes, but the part I currently find most interesting is the fact that they will be put into use in the U.S. That will be only for oil trains, but still, it seems like really big news. That is a MAJOR change in the railroad industry. And yet strangely, I find no news update on the plan or conversion underway since it was announced last spring. On the other hand, there are coherent efforts to provide ECP installations on HHFT or other consists, with high assurance and within an appropriate timeframe to meet the mandate if it stands. I know of at least two. Do not expect details on any public forum. Both in the short run that so many financial 'analysts' ruin their analysis by emphasizing, and in the potential long run if ECP use doesn't become prevalent 'enough' or the technologies they adopt become obsolescent ... as so many technologies in ECP over the years have indeed become.
Euclid I am generally interested in ECP brakes, but the part I currently find most interesting is the fact that they will be put into use in the U.S. That will be only for oil trains, but still, it seems like really big news. That is a MAJOR change in the railroad industry. And yet strangely, I find no news update on the plan or conversion underway since it was announced last spring.
Both in the short run that so many financial 'analysts' ruin their analysis by emphasizing, and in the potential long run if ECP use doesn't become prevalent 'enough' or the technologies they adopt become obsolescent ... as so many technologies in ECP over the years have indeed become.
Why not expect details of the two ECP installations on a public forum? Are you referring to details that you cannot provide due to proprietary reasons? Or are you referrring to something more general?
What are the ECP technologies that have become obsolete over the years, as you mention?
EuclidWhy not expect details of the two ECP installations on a public forum? Are you referring to details that you cannot provide due to proprietary reasons? Or are you referring to something more general?
Mostly the former, although (as you are aware of, in different context) there are patentable elements that must be protected against 'premature disclosure'.
I suspect most of the actual "competitive advantage" in implementation has more characteristics of trade-secret than actual patentable innovation -- but again, there is a reason why 'trade secrets' are kept secret...
Not to pick a nit, but I said 'obsolescent', not 'obsolete', and there is what I consider to be an important difference between those terms.
'Obsolescent' technology is still perfectly workable, and still worth supporting (if you have the interest or, for example, are 'heavily invested' in older technology, like NS was with DC traction motors). It just isn't the 'best' solution in modern terms -- it's becoming outmoded, but isn't 'there' yet. A somewhat remarkable example of this in action was the Republic Locomotive (?) 'starship' FL-9 rebuilds, which were meant to be amazingly state-of-the-possible when built, but had become difficult to maintain, and essentially unsalable to other potential FL-9 users, less than a decade later...
For examples of obsolescence in ECP over the years, start with just about ANY instantiation of actual electronic equipment or devices, and proceed directly to programming environments, test tools, magnetic materials, RF spectrum allocation, etc.
Proceed to look at how the development of consumer electronics, and common standards for industrial systems, have evolved over the years, making OTS technologies using some standards much more cost-effective even when they offer far more effective functionality. One example would be RFID, another the advances in differential GPS. At least some reasons for 'wireline' connection between cars (apart from 220V power) are no longer as 'necessary' as they were when the technology was 'frozen' and marketed.
CMStPnP Are railroads going to eventually replace compressed air with electronics
It's not really the type of investment that offers an attractive ROI, especially when you consider the number of cars out there that would have to be retrofitted to achieve universal deployment. And just consider what such a move would do the the value of all the disused cars sitting out on leased dormant lines. I'd guess that it will primarily be used in specialty applications and/or in dedicated use trains.
My guess is that you will have crewless trains before there will be a universal adoption of ECP.
WizlishGeorge O. Smith had an interesting 'take' on the legal definition of information vs. power transfer in one of his "Venus Equilateral" stories ... where he brought up, btw, the functional overlap in the applicable technologies (albeit for somewhat melodramatic plot purposes!)
When I got my EE degree from Univ. of Cincinnati, my major was in power. But I got into communications and worked with Microwave System and then Fiber Optic System design. So information does not require an electrical medium to transmit information. New disciplines come into being and you see that in your new cell phones. They outdo Dick Tracy and Star Treks communicators. In the 60's transisters couldn't work reliably under the hood of a car, (temperature extremes and rf noise) but those have been overcome. (In less than ten years) Your car today has more computing power than the early astronaughts. The early electical systems on locomotives have been replaced by sophisticated computer controls that do more than was dreamed of back in the1930's and even the 1960's. It's easy to talk about the many issues with ECP but trial and error will find the things that need improvement. While steam locomotives are great to see and ride behind, does any body think the way we used to do things is the best. While the KISS principle still has merit, I think its time to move forward with ECP and see whether the bugs can be found and removed, and determine if the benefits justify the cost.
Wizlishhe point I wanted to establish, and missed, was that electrically-controlled proportional operation of brakes was developed prior to the invention of the triple valve. erikem has, I think, corroborated this.
Getting facts straight is not a 'pissing contest' regardless of some peoples' discomfort. I read Erik's comments. I do not think he corroborated your modified contention. He said, "As for electrically controlled braking, one of Westinghouse's chief motivation for improving the triple valve was that he didn't want to use electrical control of the air brakes." So what electrically controlled air brake system existed at the time of Westinghouse's invention? I would say there was NONE. As in history and most/all other fields, show us the evidence.
Robinson's 1872 ATC used a DC current and detection, essentially a signaling/train occupation detection advance. https://www.princeton.edu/~ota/disk3/1976/7614/761411.PDF Its use was totally unrelated to the modern electronic pneumatic braking, an advance on electro-pneumatic braking (ECP), in the article which was linked by sandiego. Frank Sprague's contributions were reliable electric streetcar overhead current catching devices and MU controls.
schlimm Wizlish he point I wanted to establish, and missed, was that electrically-controlled proportional operation of brakes was developed prior to the invention of the triple valve. erikem has, I think, corroborated this. I read Erik's comments. I do not think he corroborated your modified contention. He said, "As for electrically controlled braking, one of Westinghouse's chief motivation for improving the triple valve was that he didn't want to use electrical control of the air brakes." So what electrically controlled air brake system existed at the time of Westinghouse's invention? I would say there was NONE. As in history and most/all other fields, show us the evidence.
Wizlish he point I wanted to establish, and missed, was that electrically-controlled proportional operation of brakes was developed prior to the invention of the triple valve. erikem has, I think, corroborated this.
I read Erik's comments. I do not think he corroborated your modified contention. He said, "As for electrically controlled braking, one of Westinghouse's chief motivation for improving the triple valve was that he didn't want to use electrical control of the air brakes." So what electrically controlled air brake system existed at the time of Westinghouse's invention? I would say there was NONE. As in history and most/all other fields, show us the evidence.
SD70M-2Dude Interesting, can the ECP-equipped cars be mixed with conventional ones in a train, or are they not interoperable? And even if ECP can be made interoperable with conventional air brakes there will still be a big obstacle to its adoption over here: the Class I's love of the status quo and resistance to change of any kind.
Cars equipped with ECP braking only are not interoperable in normal terms since electrical power from the 250 v DC train bus line is needed to actuate the brake valves. There is an "emulation" mode where the cars can be switched and transferred short distances using the ECP system reacting to brake line pressure with power supplied by batteries on the car.
This is generally enough to move cars to workshops for maintenance.
Some cars are dual fitted with both ECP and conventional triple valves but require to be switched between modes (I believe manually, car by car). One operator in Australia, Centennial Coal have two rakes which are dual fitted.
The first batch of Glencore hoppers arrived with full ECP equipment but were set up to use triple valves so that they could be hauled by conventional locomotives until the new locomotives were available, when the triple valves were removed and they used ECP exclusively.
While it would cost more to fit both ECP and conventional braking, it would meet the requirements of interoperability. Procedures would have to be instituted to ensure that the vehicles were in the correct mode for whichever type of train it is to be included.
The downturn in coal traffic has reached Australia, and in addition, Pacific National has lost a major haulage contract to Freightliner. Apart from involving a change from conventional to ECP trains, it is suggested that Pacific National with withdraw many of its ballasted non ECP DC traction coal locomotives, since they cost more to run than AC units hauling ECP trains.
Euclid I would think that if Westinghouse announced that he was against electricity and for compressed air, that would indicate that there were a lot of people advocating electricity for train brakes at that time-- for both powering and controlling.
If we see evidence, so much the better. But keep in mind railroad engines did not have generators for lighting passenger cars until well after Westinghouse introduced his triple valve. Pintsch lighting systems were commonly used on many lines into the 20th century, when electric lights replaced them for safety reasons. So it seems highly unlikely that others were advocating electric braking in the 1875-1890 period.
First, I'm not getting into a discussion of the meaning of electric vs electronic.
In the book "The American Railway" (about 1889), H. G. Prout, editor, "Railroad Gazette" writes of the Burlington brake-trials of 1886 & 1887. He says that in 1887 "it was shown that by bringing in electricity to activate the air valves, the application of the brakes could be made practically simultaneous throughout the train." He then adds that Westinghouse made improvements to his system that made his system practical.
The book is here:
https://archive.org/details/americanrailway00clargoog
I loaded it in PDF. Go to page 200 in the book (PDF page 235).
PoC,
Another reference is White's The American Railroad Passenger Car pages 555-556. This was after the original triple valve but contemporary with the quick action valve. WABCO introduced the HSC electro-pneumatic brake in 1932 for high speed passenger car service.
Compressed air does have a lot of advantages for powering brakes - the compressed air by itself is a form of stored energy, just needing a pressure vessel of some sort. An additional advantage is that an air leak does not create an environmental problem.
Thank you both for the research. The idea of using electricity to activate braking in some manner did not seem to catch on here, although it did in Great Britain in passenger services.
schlimm Euclid I would think that if Westinghouse announced that he was against electricity and for compressed air, that would indicate that there were a lot of people advocating electricity for train brakes at that time-- for both powering and controlling. If we see evidence, so much the better. But keep in mind railroad engines did not have generators for lighting passenger cars until well after Westinghouse introduced his triple valve. Pintsch lighting systems were commonly used on many lines into the 20th century, when electric lights replaced them for safety reasons. So it seems highly unlikely that others were advocating electric braking in the 1875-1890 period.
During the power brake development era, one method was the so called momentum brake, or buffer brake.
schlimm Thank you both for the research. The idea of using electricity to activate braking in some manner did not seem to catch on here, although it did in Great Britain in passenger services.
erikem schlimm Thank you both for the research. The idea of using electricity to activate braking in some manner did not seem to catch on here, although it did in Great Britain in passenger services. I beg to differ. Electro-pneumatic braking was used on several streamliners from the beginning of the streamline era, though it was not universally applied to US locomotive hauled passenger trains. Anti-lock braking is, AFAIK, almost universal on passenger rail cars. As an example, the Pacific Surfliner cars have a Hall-efffect sensor mounted next to a toothed wheel on the axle ends for providing rotational speed data. - Erik
My favourite answer to people who suggest that the USA didn't use EP braking is:
"What do you think the the third turbogenerator on an SP GS-4 or GS-5 4-8-4 is used for? First one for headlight, Second one for Mars light, third one for electropneumatic braking."
When STEAM trains had EP brakes, the system had well and truly been adopted...
erikemI beg to differ. Electro-pneumatic braking was used on several streamliners from the beginning of the streamline era, though it was not universally applied to US locomotive hauled passenger trains.
I knew that. I think the UP's M-10000 or maybe Pioneer Zephyr? But widely used in GB.
schlimm erikem I beg to differ. Electro-pneumatic braking was used on several streamliners from the beginning of the streamline era, though it was not universally applied to US locomotive hauled passenger trains. I knew that. I think the UP's M-10000 or maybe Pioneer Zephyr? But widely used in GB.
erikem I beg to differ. Electro-pneumatic braking was used on several streamliners from the beginning of the streamline era, though it was not universally applied to US locomotive hauled passenger trains.
I think the use in UK was largely in the very late 1940s and 1950s...
Mainly on the Southern Region of BR where extensive main line electrification occurred.
British Steam locomotives rarely had electric lighting, let alone EP brakes as the GS-4 had in 1941. Of course the UK was at war from 1939, effectively on a war footing from 1937-38 so had less incentive for these developments.
Without looking, I believe in a 1980 (November?) issue of Trains about delivering EMD locomotives, there is a tale involving passenger EP brakes. As I recall it was on the CNW and the engineer was relating about how he was running the streamliner (joint UP/CNW/SP operation) that was EP equipped. It had two indicator lights, one that the EP was working, one that it had failed and a selector lever to change over between the EP and normal air brake operation. Approaching a speed restricted curve they were starting to slow for it when the EP failed. He couldn't change over quick enough and make a regular brake application so they went around the curve faster than they should have.
I was given a cab ride in a suburban train by the driver, who was a friend. The subject of EP brakes came up and he said he'd demonstrate the difference between EP and Westinghouse brakes. He isolated the EP system, and showed the difference in braking performance.
In the first station, we overran by a couple of metres but as we approached the second station on a falling grade, the driver said "that's enough, I don't think we'll stop in time without EP.." and turned it back on again.
Many years ago I measured coupler forces in 200 car iron ore trains of 30 000 tons. The tension forces were scary but the compression loads in dips were amazing. I've been a fan of EP and ECP ever since.
Aside from the references so far provided, it might be valuable to remember that an electrically-controlled brake setup in the years before the triple valve would almost certainly have used batteries, not dynamos, for power. (The Page and Daniell cell chemistries being two notable choices, and Edison's nickel-iron structure being a later example of a 'workable' alternative). In that period it was common for signal systems to run entirely on batteries (see the centennial 'book' on safety systems put out by Westinghouse for a discussion), and these would have adequate current and life for the applications where electricity would be perceived as cost-effective (in other words, passenger and mail trains that justified their expenses).
There were reasons why the Page cells that Benjiman Silliman, Jr. thought would be the 'future' of electric locomotive traction turned out NOT to be. erikem will have some interesting comments on the 'by-products' of generation of the necessary high currents from them...
I've never questioned the basic assumption that electrically-operated brakes would fail principally on the issue of cost, and secondarily (for the same general reason as the original straight Westinghouse air brake) on it not 'failing safe' (see the British embracing of the vacuum/Eames brake because it could.) Note that even with the 'automatic' triple, there is a perfectly easy way to assure both proportional operation and full graduated release (although of course with worse latency than an electrically-controlled or electronic system): use a two-pipe system, where the control air is in one line, and the 'power air' in a constantly-charged main as in regular ECP. ISTR that Westinghouse actually favored this system, but the 'cheaper' one-pipe won out in the marketplace.
The Decelakron is of notable interest for being an analog, mechanical solution to the problem of increased wheelslide from high-speed air braking (where it is functionally difficult or impossible to modulate application pressure for high vs. low speed on the cars, and high-performance braking, particularly with disc brakes, is needed for higher speeds in restricted block length). See the discussion of decelostats that ends here:
http://www.atdlines.com/pdf/trucks/pv_68.pdf
It's easier, of course, to implement 'antilock' action if you have a Hall-type speed signal that can modulate an electric magnet valve than if you need a mechanical linkage of some kind to a physical valve with seals or seats. But, as schlimm notes, you need an effective power supply (and not just one that produces increasing voltage with increasing car speed, and that starts only with the car moving at meaningful speed, like a Spicer generator) and in the age of steam this involved batteries or dedicated generators on some kind of trainline.
Correct me if I am wrong, but to my knowledge none of the commuter services that used 'trainlined' electric lighting from a dynamo on the engine or a special car also used any kind of electropneumatic assistance in braking whatsoever. And I'd think offhand that this would be a useful niche for that...
One thing that is probably slowing the adoption of ECP is the widespread use of distributed power on long trains. The slave locomotives can initiate a brake application too, making a 100 car train brake much closer to a 50 car train.
Redore One thing that is probably slowing the adoption of ECP is the widespread use of distributed power on long trains. The slave locomotives can initiate a brake application too, making a 100 car train brake much closer to a 50 car train.
2-way EOT's are in almost universal use on line of road trains. In addition to reporting rear end air pressure and movement to the lead locomotive, the engineer can initiate an emergency brake application from the EOT.
BaltACD2-way EOT's are in almost universal use on line of road trains. In addition to reporting rear end air pressure and movement to the lead locomotive, the engineer can initiate an emergency brake application from the EOT.
If they could modify the EOT to assist in a service application that would be helpful.
Norm48327 BaltACD If they could modify the EOT to assist in a service application that would be helpful.
BaltACD
JeffHergert would be the one to ask about the usefulness of a service application from a DP unit, as he runs them. I question the benefit of initiating a service application from the rear of the train, but I just dispatch them, I don't run them.
Norm48327 BaltACD 2-way EOT's are in almost universal use on line of road trains. In addition to reporting rear end air pressure and movement to the lead locomotive, the engineer can initiate an emergency brake application from the EOT. If they could modify the EOT to assist in a service application that would be helpful.
BaltACD 2-way EOT's are in almost universal use on line of road trains. In addition to reporting rear end air pressure and movement to the lead locomotive, the engineer can initiate an emergency brake application from the EOT.
I don't know about situation on other railroads, but on Canadian National our EOT's used to be used in this manner. It was called Brake Assist, but it had a major problem in that the EOT's vent valve would sometimes stick open and keep venting the brake pipe pressure for long after the desired reduction had been achieved. Because of these problems, the decision was made before I hired on to stop using this feature, and now if crews find it enabled on an EOT we are to disable it.
SD70M-2Dude It was called Brake Assist, but it had a major problem in that the EOT's vent valve would sometimes stick open and keep venting the brake pipe pressure for long after the desired reduction had been achieved. Because of these problems, the decision was made before I hired on to stop using this feature, and now if crews find it enabled on an EOT we are to disable it.
I am an outsider, but this seems like a problem that could be fixed rather than abandoning the whole idea.
We've had discussions on ECP brakes before, and it still seems to me that several such EOT's (or MOT's) placed in the train (say every 20 cars or so) would produce control approaching that of ECP brakes, with the one big exception of graduated release.
Paul of Covington We've had discussions on ECP brakes before, and it still seems to me that several such EOT's (or MOT's) placed in the train (say every 20 cars or so) would produce control approaching that of ECP brakes, with the one big exception of graduated release.
Paul of Covington SD70M-2Dude It was called Brake Assist, but it had a major problem in that the EOT's vent valve would sometimes stick open and keep venting the brake pipe pressure for long after the desired reduction had been achieved. Because of these problems, the decision was made before I hired on to stop using this feature, and now if crews find it enabled on an EOT we are to disable it. I am an outsider, but this seems like a problem that could be fixed rather than abandoning the whole idea. We've had discussions on ECP brakes before, and it still seems to me that several such EOT's (or MOT's) placed in the train (say every 20 cars or so) would produce control approaching that of ECP brakes, with the one big exception of graduated release.
It probably could be fixed with enough time and money, but all our trains have still been running without it for years now and apart from in training classes and rulebooks I have hardly heard it mentioned, so it doesn't seem to have been enough of a help to be missed.
But keep in mind that EOT's have been around for over 30 years, and we still have problems with their emergency valve, often due to it freezing in the winter. Valves on cars & locomotives, and indeed any air valve of any kind in an unheated outdoor environment will (and do) encounter this same problem, and 100 years of railway air brake technology hasn't come up with a cost-effective way of eliminating it (maybe global warming will ). The standard method of fixing the problem is for the Conductor to head outside and cut off the air supply to whatever valve is leaking, wait a bit and then cut it back in slowly and hope the valve has reset itself. As you can imagine walking back 11,000 feet to troubleshoot an EOT takes a while.
I should add that emergency valves sticking open is a managable problem since this pretty much only happens after they are opened intentionally, either during a test or when the engineer places the tail end in emergency on purpose. During the first example the Conductor is standing beside the EOT, and the second happens so seldomly that delays caused by this valve are livable (and it often resets itself in the time before the engineer recovers his PC on the head end and air pressure gets to it again). Brake Assist required the valve to open multiple times a day while the train was moving, so any problem with it quickly spiraled into a several hour delay, especially if it accidently triggered an emergency application and the associated violent in-train forces broke a knuckle or drawbar, or caused a derailment (known to happen).
Also remember that any fix you make has to be light enough for a Conductor to carry with one arm, and EOT's are already heavy.
Another thing to keep in mind is that many (most?) of our trains now run DP, especially in cold weather. This is a proven and reliable technology that not only allows brake applications to take effect quicker, it also provides several other benefits that Brake Assist never could, such as lower in-train forces and quicker air brake releases. Another innovation is the Distributed Braking Car, which is a converted boxcar or well car with a diesel genset-driven air compressor and a radio receiver inside, which responds to the engineer's braking commands on the lead locomotive, just like a DP locomotive. They have problems too, but seem to provide enough improvement to be worth investing in.
I know I ramble, but to sum up Brake Assist on EOTs was a worthy idea but it turned out to not have a good enough cost-benefit ratio to justify working out its inherent problems, especially when other superior technologies were available.
Thanks, SD70M-2Dude, and ramble on; I welcome the information. I hadn't given much thought to cold weather problems.
The "air containers" show up quite regularly in Calgary, probably used on trains 114/115 from Toronto.
http://www3.telus.net/jsuther9/rails/2016-01-31Aa-Sarcee-CN0009-CNSU0009.jpg
cx500 The "air containers" show up quite regularly in Calgary, probably used on trains 114/115 from Toronto. http://www3.telus.net/jsuther9/rails/2016-01-31Aa-Sarcee-CN0009-CNSU0009.jpg
I'm pretty sure they had boxcars so equipped in the past.
tree68 I'm pretty sure they had boxcars so equipped in the past.
You are quite correct, although I never got around to taking any pictures of the boxcars. I think they may have been acquired 2nd hand from another railroad. I haven't noticed any lately, but haven't really been looking.
I'm not sure what percentage of CN's road power has DPU capability enabled, which may be why they are using these cars as a solution to winter air woes.
"+1" on the rambling, too. Oh wait, excuse me, now it's called: "data transfer" !
- Paul North.
cx500...which may be why they are using these cars as a solution to winter air woes.
I was of the understanding that they were for exactly that purpose - to help keep the air up in cold weather throughout the train.
The boxcars were aquired from another railroad, BN I believe but am not certain. I also heard that Great Northern experimented with air repeater cars, so the concept is not new.
The air containers are placed in the bottom position on a regular well car. They are not confined to intermodal trains either, and have been seen in mixed freights too.
schlimm The Southern Region of BR introduced the electro-pneumatic system for suburban passenger service in Britain in 1950. Still electric, not electronic.
I was reading Practical Helps for the Electric Railway, (C) 1919 by the Electric Railway Journal and came across a couple references to electro-pneumatic braking. One reference was for the New York Municipal Railway use of electro-pneumatic braking along with a means for adjusting the braking force based on the weight of the car - passenger weight could be as high as 40% of the empty weight of the car. Comments were made that the system permitted graduated application and release under electric control.
Euclid Backing up a bit: Does anybody have a further explanation or a link to information about using an EOT to mirror a service application of air brakes when one is initiated from the cab?
Would an End of Train Device be able to replicate all of the actions of a locomotive brake controller? It would need a pretty complex air brake valve and serious control data arriving by radio link...
Has anyone done a survey to see if Railroads resisted the Westinghouse automatic air brake when first intoduced as seriously as they are trying to avoid ECP brakes.
All these suggestions about how to get a result not quite as good as ECP by adding complications to the existing system sound like saying that by using more brakemen spaced down the train and developing a better set of whistle signals would give you a result nearly as good as air brakes (as an excuse for not adopting air brakes).....
I'm told that Pacific National, the largest single operator of coal trains in the Australian Hunter Valley (leading to Newcastle, the largest coal export port in the world) have started storing locomotives not fitted with ECP braking and are planning to convert the remainder of their fleet to ECP. PN's main competitors, Aurizon and Freightliner (a G&W operation) run all ECP trains and PN have about half their fleet ECP now.
Note that the decision to go all ECP by all three operators was a straight business decision. No government authority cares either way.
M636CWould an End of Train Device be able to replicate all of the actions of a locomotive brake controller? It would need a pretty complex air brake valve and serious control data arriving by radio link... Has anyone done a survey to see if Railroads resisted the Westinghouse automatic air brake when first intoduced as seriously as they are trying to avoid ECP brakes. All these suggestions about how to get a result not quite as good as ECP by adding complications to the existing system sound like saying that by using more brakemen spaced down the train and developing a better set of whistle signals would give you a result nearly as good as air brakes (as an excuse for not adopting air brakes)..... I'm told that Pacific National, the largest single operator of coal trains in the Australian Hunter Valley (leading to Newcastle, the largest coal export port in the world) have started storing locomotives not fitted with ECP braking and are planning to convert the remainder of their fleet to ECP. PN's main competitors, Aurizon and Freightliner (a G&W operation) run all ECP trains and PN have about half their fleet ECP now. Note that the decision to go all ECP by all three operators was a straight business decision. No government authority cares either way. M636C
OK, you lost me a little bit. Where did you read or infer that the railroads do not want ECP? Both BNSF and UP have stated publicly they want ECP but have other priorities on the table now, most specificly PTC.
They stated they wanted to phase in ECP at some future date when they can afford it on coal trains and/or intermodal trains first since all the cars are the same and in one pool. They are not sure about mixed car freights and when the conversion for those will be feasible. They said right now they have higher priorities with their capital budgets but that ECP is definitely and item on their future wish list.
So ECP is comming. Don't know when and thats why I started the thread, I was curious if anyone had a number of years outlook or more info on this.
CMStPnP OK, you lost me a little bit. Where did you read or infer that the railroads do not want ECP? Both BNSF and UP have stated publicly they want ECP but have other priorities on the table now, most specificly PTC. They stated they wanted to phase in ECP at some future date when they can afford it on coal trains and/or intermodal trains first since all the cars are the same and in one pool. They are not sure about mixed car freights and when the conversion for those will be feasible. They said right now they have higher priorities with their capital budgets but that ECP is definitely and item on their future wish list. So ECP is comming. Don't know when and thats why I started the thread, I was curious if anyone had a number of years outlook or more info on this.
Have BNSF and UP (or third parties providing vehicles for coal trains) not purchased new coal wagons in the last ten years?
It would be easy to equip all new wagons with ECP but use a triple valve (with manual changeover) until enough cars are in service to convert a full train. Then you switch over, train by train, to ECP....
If a car has to run in a non ECP train, just change it back to conventional...
It is like the joke about Pyschiatrists and light bulbs: "How many Pyschiatrists does it take to change a light bulb? Only one, but the light bulb has to want to change...."
It is beginning to look like changeover to ECP in the Hunter Valley will take about fifteen years - we are at the ten year mark now.
It was the arrival of competitors using ECP that caused Pacific National to start changing.
If that hadn't happened, they might still have the view that it would be nice to have it in the future.
Perhaps it is the contributors on the forum that keep looking for reasons not to use ECP. But it seems to be viewed as something that isn't easily attainable.
All the Australian cars are fitted with ECP equipment from Wabco and NYAB and other USA suppliers using AAR standard fittings. There is nothing to be tested or invented. You just have to start buying it, and soon you'll have a set of trains that run faster, cost less to maintain and spend longer in service between maintenance.
Since you raised the subject of PTC, I'm less convinced of the benefits there, although Rio Tinto have been running trains without any fixed signals now for more than ten years. Rio are planning to convert over to complete driverless operation based on their system which they call "in cab signalling".
PTC has been introduced or at least tested on some busy single track sections of the national network but I feel that more double track would have a much bigger impact on traffic flow than just allowing trains in the same direction to run closer together...
Euclidbut the grim reality of universal conversion has set in.
More like the grim reality of congress mandating the railroads spend their own money on something that is of little benefit to them. PTC is a huge expenditure that the railroads have to cover. There is just so much money in the coffers yet congress thinks the rails have unlimited budgets.
Norm48327 Euclid but the grim reality of universal conversion has set in. More like the grim reality of congress mandating the railroads spend their own money on something that is of little benefit to them. PTC is a huge expenditure that the railroads have to cover. There is just so much money in the coffers yet congress thinks the rails have unlimited budgets.
Euclid but the grim reality of universal conversion has set in.
M636CHave BNSF and UP (or third parties providing vehicles for coal trains) not purchased new coal wagons in the last ten years?
I don't have any idea on their equipment purchases but both BNSF and UP in the progressive railroad article I read have ECP equipped freight trains they have tested in Coal Unit Train service. Not sure about intermodal as I only scanned the article.
Someone correct if wrong. Early EMUs including subways migrated to electric braking control from air only. Only with separations of a train would air system apply brakes in emergency.
Now almost all EMUs being built have provision for most braking to be regenerative. For those transit systems or some system routes not yet with provisions for regeneration the regeneration is disabled. Now only if regeneration is not working for any reason is electrical braking used with the air backup.
Amtrak has provisions thru the car control ( not loco control ) 27 point connectors to apply brakes electrically. But with the extended range dynamic / regeneration now available Amtrak has not pursued that option. The blended brake system seems to work fine. Now it could be the if a lenghtened Amtrak Autotrain is allowed then electric braking might be activated on those trains in certain conditions.
Probably one thing holding back implemation of ECP on unit trains (aside from cost and the fact that the money is needed for PTC right now) is the fact that unlike captive lines running unit trains, any car in any train must be capable of being handled as a single car.
Inasmuch as general traffic will likely be the last to get ECP, an ECP equipped car must be able to be handled by a non-ECP train should it need to be set out for any sort of problem. If it can't be handled as standard brakes, it needs to be handled as a car without brakes, which has its own set of conditions.
Of course, this issue has been discussed before.
Railroads aren't the only industry facing such issues. The fire service has been campaigning for years for residential sprinklers (in the house, not on the lawn). This is also a proven technology which will save lives and property. Chief objection (from the builders) is the additional cost to the home buyer (around $1.50 per square foot).
tree68The fire service has been campaigning for years for residential sprinklers (in the house, not on the lawn). This is also a proven technology which will save lives and property. Chief objection (from the builders) is the additional cost to the home buyer (around $1.50 per square foot).
I had an experience while in college. I was a student stage electical operator and ran the light board. Back when the auditoium was built, the board had wiring that was rubber and cloth insulation and the light dimmers were big pancake rheostats that put out a lot of heat. The head stage electrician was a former pullman conductor, (Dry campus, he still loved his whiskey) but he was off, and another student was left in charge one day. Got a call from him that the board just burned up. When I got there, it seemed like all of Cincinnati's fire department was there. Sprinklers contained it. Only casualty was the board. Smoke damage clean up and aquiring a new board put the place OOS for about five month's. Turned out that someone had installed an outlet by the board but had just fed it from the bus bars with #12 wire and NO FUSE. Plug in a defective cord and the wire overheated, burst into flame and ignighted the boards wiring. Made an impression.
By the way, is your house sprinkled?
Electroliner 1935By the way, is your house sprinkled?
Unfortunately, no.
Then, again, it was built in 1840 with real lumber (as opposed to the toothpicks and cardboard they use these days).
And there is the cost - while new construction can run $1.50 a square foot, retrofits are closer to $5.00 a square foot (and up). At this point in my life, I'll settle for safe practices and working smoke detectors.
If I built a new one, I'm sure I'd include sprinklers.
One thing I may not have mentioned it that while the Iron Ore lines in the Pilbara in Western Australia have pretty much fully converted to ECP being the "captive lines running unit trains" Tree68 mentioned, the Hunter Valley lines carry passenger trains and the coal trains of the three major operators and other freight (intermodal, grain, cement and heavy metal concentrates mainly) from at least three additional operators. There are dedicated "coal lines" for about twenty miles from the port, but these were opened a hundred years ago to separate trains of privately owned coal wagons with no air brakes from the passenger trains. They now keep the ECP brake coal trains from being delayed by commuter trains.
So the ECP coal trains run among non ECP coal and non ECP general freight and passenger trains (all of which have EP brakes).
The same situation applies in Central Queensland where ECP coal trains (both diesel and electric hauled on the same lines) and non ECP coal trains (both diesel and electric) from three operators Aurizon, Pacific National and BMA share with general freight and passenger traffic.
On both systems, the need to set out ECP cars has been almost negligible, partly at least because ECP makes the cars more reliable by reducing brake wear and wheel defects caused by sticking triple valves at the rear of long trains.
Before they converted to ECP Rio Tinto made up their trains with the oldest cars in the middle, and put their newest cars on each end so that the newest triple valves were always trailing, and they didn't do that because someone thought it looked good.
A straight ECP car can be run in a normal train under battery power with the ECP valve emulating a triple valve and this should cover most emergencies. A car which might need to operate for extended periods could be fitted with both ECP and conventional brakes (at the extra cost of only the triple valve) but this requires manual changeover.
In Australia, there is almost no loose car traffic. Cars are switched between trains en route, but most trains are dedicated intermodal, steel, coal or grain. Pacific National started adding steel cars to intermodal and vice versa at the beginning of the last economic downturn so that they could maintain the same service with fewer trains.
But in Australia, the need for interoperability is no less, the operators have just decided that ECP will save them money and went ahead with it.
I would expect that there will be a gradual decline in loose car operation in the USA. I believe more freight goes in intermodal trains than loose cars now.
And since the USA railroads own their own track, they must have fewer external reasons not to adopt ECP.
It's been my understanding, perhaps wrongly, that the first cars equipped with ECP equipment will be be capable of operating in either ECP or conventional mode. That is, if a car is in a train made up of all ECP capable cars and operated in that mode, the car's brake system would be in ECP mode. If that car is set out for mechanical reasons, it would be able to be picked up by a conventional train. It's brake system then working conventionally. (It's the same with the locomotive brake valves. They will be able to work in one mode or the other, but not both at the same time.)
I've seen some newer equipment over the last few years (mainly hoppers, both open and covered) that have air brake equipment with some extra hoses and other hardware that I've been told has to do with ECP. Those cars aren't fully equipped, but the extra items make a conversion to ECP that much faster later on.
I'm not sure that ECP will allow faster freight trains in the US. While it might eliminate or modify some tons per operative brake restrictions for some trains, I don't think it will make heavy bulk commodity trains less damaging to the track structure. I don't see them raising the speed for loaded coal trains above the current 50 mph for us.
I don't think actual speeds will increase, but ECP's quicker brake application and release rates will allow trains to travel at track speed for longer and thus get over the road faster.
NorthWest I don't think actual speeds will increase, but ECP's quicker brake application and release rates will allow trains to travel at track speed for longer and thus get over the road faster.
Don't count on it with the implementation of PTC and the use of 'Trip Optimizer' and similar applications.
On a visit to Jilalan in Central Queensland a few years ago, when Pacific National had just started running their ECP trains and Aurizon were only operating non ECP trains, I was waiting at the north end of this big yard to photograph coal trains on their way to Dalrymple Bay (the second largest coal export port in Australia).
Owing to congestion at the port, these trains may have to stop at any of four or five signals between the yard and the port, and the Aurizon trains with their three electric locomotives crept through at maybe ten miles an hour ready to stop at any signal ahead.
The Pacific National trains rolled through at 30 miles an hour, not track speed but relatively much faster. I recall this because I missed a photo of the PN train as I'd not left myself enough time to get in position.
The difference was that the ECP train could run faster confident that it could stop in a much shorter distance without damage to the train.
Another demonstation in the Hunter Valley was a signal failure at Tarro. At the time, there was a crossover to allow loaded trains to use the westbound (empty) track if the eastbound (loaded) track was congested with standing loaded trains.
I had observed a signal technician working at the crossover and the associated westbound signal protecting the crossover.
An Aurizon westbound empty coal train approached pretty much at track speed (50 MPH for unit trains) and headed under the road bridge I was standing on.
The next thing I noticed, as I turned to look at the receding train was that the westbound train had stopped well clear of the crossover signal. There was no run in or even noticeable noise. The train just stopped silently from 50 MPH in less than its length (it was empty).
I looked at the signal and it was displaying red, amber and green aspects at about one second intervals in succession continuously. It is clear why the train made what must have been an emergency stop, but it did so without any longitudinal train action and it departed without a single skidded wheel as soon as Control explained that the track was clear and the signal had failed.
Both these examples support North West's contention that trains will get over the road faster with ECP braking.
And remember, this isn't theory. These trains run like this every day, and the owners are happy to spend whatever extra it costs to get both the improved performance and the reduced maintenance. Suppose the train affected by the failed signal had been a conventional train with eighty empty hoppers. Even with the relatively new Westinghouse equipment with empty/loaded detection, I don't imagine they would have avoided a few skidded wheels in an emergency stop from 50 MPH.
None of this is theory. It works every day. The equipment comes from US suppliers like Wabco. It is off the shelf. All you have to do is buy it and watch your operating costs fall away.
M636C Euclid Backing up a bit: Does anybody have a further explanation or a link to information about using an EOT to mirror a service application of air brakes when one is initiated from the cab? Would an End of Train Device be able to replicate all of the actions of a locomotive brake controller? It would need a pretty complex air brake valve and serious control data arriving by radio link... Has anyone done a survey to see if Railroads resisted the Westinghouse automatic air brake when first intoduced as seriously as they are trying to avoid ECP brakes. All these suggestions about how to get a result not quite as good as ECP by adding complications to the existing system sound like saying that by using more brakemen spaced down the train and developing a better set of whistle signals would give you a result nearly as good as air brakes (as an excuse for not adopting air brakes).....
Just to be clear, I was not advocating such an EOT alternative to ECP. I agree with your assessment of the complications of making a service application with the EOT that mirrors one made from the head end. I mentioned those complications earlier. My point in asking for further information was simply to see verification that such a system has been in use, as was said to be the case by someone earlier.
Why do you think there is reluctance to adopt ECP for the U.S. railroad system?
Euclid My point in asking for further information was simply to see verification that such a system has been in use, as was said to be the case by someone earlier. Why do you think there is reluctance to adopt ECP for the U.S. railroad system?
My point in asking for further information was simply to see verification that such a system has been in use, as was said to be the case by someone earlier.
M636C All the Australian equipment involved uses couplers and brakes that reflect AAR standards and the ECP equipment is from US suppliers. It is no more difficult to convert to ECP in the USA than Australia but in Australia, much, maybe most of the total freight task by weight is carried on ECP trains while in the USA, as far as I can tell none is.... If there is a positive return on investment from ECP in Australia, the same must apply in the USA. So why is there a ten year lead in applying ECP brakes in Australia? The only reason I can see is reluctance by US railroads to use equipment they could buy off the shelf, today, in large enough quantities from US suppliers to fit entire unit trains they are already operating. M636C
http://cs.trains.com/trn/b/fred-frailey/archive/2015/05/13/railroads-and-their-money.aspx
(Fred Frailey blog May 13,2015)
Euclid The Cartier Railway in Canada uses ECP brakes: http://www.canadianminingjournal.com/features/quebec-cartier-pioneers-safer-more-efficient-railroad-brakes/ Clearly ECP offers benefits, but there is one factor of performance that I believe has been misrepresented in bad faith. That factor is stopping distance. ECP is typically promoted as offering a dramatic reduction in stopping distance. But the claim carefully avoids the condition that it only applies to “Service” applications. For “Emergency” applications, the ECP stopping distance advantage is minor. It is an odd stipulation that would only come into play with train brakes. For any other type of vehicle, “stopping distance” naturally implies “shortest stopping distance.” So I conclude that ECP promoters have been intentionally disingenuous in the claim of shortening stopping distance. Perhaps that is one reason why we now have an ECP mandate for oil trains.
M636C I was on a Rio Tinto (then called Hamersley Iron) iron ore train that made an emergency application in 1978. The train was within sight of the "Seven Mile" yard when the yard controller changed his mind about which track we were to use and a signal reversed from green to red as we approached at about 40 MPH. To avoid passing the signal at red, the driver applied emergency braking. The train consisted of a C36-7 leading and two M636 with 220 cars carrying 100 long tons of ore each. These cars were married pairs with drawbars, so there were only 110 triple valves. It was a warm fine clear day. The load behind the locomotives would have been around 25 000 long tons. We were lucky not to derail. The train broke in five places, one being a drawbar that pulled out of a broken yoke. Fortunately we were on double track so we didn't block the line but it took hours to get the train into the yard. M636C
First off - whoever took the signal down without contacting the engineer of the train to see if he could make a controlled stop of the train BEFORE passing the signal should be FIRED! Taking a signal away without notice is a sure way to create the mess you discribed - no matter the braking system.
M636CPerhaps many USA railroad managers have never been on a locomotive
Fixed that for you.
M636C Euclid The Cartier Railway in Canada uses ECP brakes: http://www.canadianminingjournal.com/features/quebec-cartier-pioneers-safer-more-efficient-railroad-brakes/ Clearly ECP offers benefits, but there is one factor of performance that I believe has been misrepresented in bad faith. That factor is stopping distance. ECP is typically promoted as offering a dramatic reduction in stopping distance. But the claim carefully avoids the condition that it only applies to “Service” applications. For “Emergency” applications, the ECP stopping distance advantage is minor. It is an odd stipulation that would only come into play with train brakes. For any other type of vehicle, “stopping distance” naturally implies “shortest stopping distance.” So I conclude that ECP promoters have been intentionally disingenuous in the claim of shortening stopping distance. Perhaps that is one reason why we now have an ECP mandate for oil trains. That Quebec Cartier reference is nine years old.... There are four similar railroads in Australia that are fully ECP: BHP Billiton, Rio Tinto, Fortescue and Roy Hill. But none in the USA? Is shortening the stopping distance the only measure of merit for emergency braking?
You ask why U.S. railroads are not enthused about ECP. Whatever their reasons, I would say they elaborated on them with the greatest clarity in the month or so leading up to the oil train ECP mandate. Prior to that, I don’t recall much argument against ECP.
Don't locomotives still have independent brakes? The engineer must be sure to use the train brake if he needs to stop quickly. Fifty-three years ago, I was going up to Bristol on the Pelican. Just before we were ready to leave Birminghm by heading out to the main, an L&N train began coming down to the crossing with the Southern--and the L&N gate watchman threw the gate across the Southern track almost in the face of the engineer of a freight that was headed for Sheffield. Sad to say, the engineer of the Southern freight must have had his hand on the independent brake valve, for he stopped the engine in time--and derailed some of the cars and blocking both tracks to the main. As it was, we were able to back to North Birmingham and then use another track to Woodlawn Junction and take the main from there. I do not doubt that the L&N watchman and the Southern engineer were spoken to sharply.
Johnny
BaltACD First off - whoever took the signal down without contacting the engineer of the train to see if he could make a controlled stop of the train BEFORE passing the signal should be FIRED! Taking a signal away without notice is a sure way to create the mess you discribed - no matter the braking system.
I wasn't involved in the enquiry followng the incident but I believe they started off by blaming the locomotive crew.
The operator in the yard tower should have been able to see our headlight although he might not have realised how close we were.
The same situation can be created by a motor vehicle driving onto a grade crossing without looking.
My view is that the yard controller was at fault, but my point was that the stopping distance in emergency braking is not the only consideration. Emergency is just that. It isn't one more step in controlled braking, it is intended for life or death situations and the current air brake system does an excellent job of stopping a train in a minimum distance.
I've seen ECP trains stop just as quickly. What impressed me was the much greater degree of control during maximum braking.
The same sort of yo-yo effects occur on the road every time a long train brakes, and problems can occur in starting if the rear of the train hasn't released its brakes by the time it starts moving.
I actually had instrumented couplers measuring train forces on that particular train but of course the equipment was turned off at the time. I would have loved to know what the forces were. It might not have been recorded anyway. There was 2000 metres of coaxial cable strung down the side of the train which just disappeared in the whiplash. We never found any of it and it cost then a dollar per metre.
Euclid What difference does it make how old the Cartier reference is? It is still pertinent. And is also making your argument. In any case, I was not offering the reference to Cartier as part of a competition between the U.S. and Australia. Regarding your question as to whether stopping distance is the only measure of merit: No, there are other measures of merit, but again, I was not referring to stopping distance as part of a compilation of pros and cons in a competition between ECP and conventional air brakes. I have no stake in either one. My point was only about stopping distance, and my feeling that it has been used to misrepresent ECP. The stopping distance is around 5% shorter with ECP in the “Emergency” application, as you say. But I have seen many references that simply state that the stopping distance with ECP is around 60-70% less than with conventional air brakes. They never say that is the stopping distance for “Service” applications only. Regardless of all the other benefits, quick stopping is the one that the most people can relate to in regard to safety concerns. And at the same time, they will have absolutely no clue that there are TWO different kinds of stopping distance. As you must know, the U.S. railroads vigorously argued against the need for ECP brakes on oil trains when the mandate loomed up. Their strongest argument was that the conventional air brakes could stop in “Emergency” almost as quickly as ECP brakes; if the train with conventional air brakes were equipped to dump the air from the road engine, the EOT, and the distributed power locomotives simultaneously. You ask why U.S. railroads are not enthused about ECP. Whatever their reasons, I would say they elaborated on them with the greatest clarity in the month or so leading up to the oil train ECP mandate. Prior to that, I don’t recall much argument against ECP.
As far as this poster can see the jury is still out on ECP. However maybe it needs to be looked at in a different way. It may be mixed freight trains need ECP much more than unit trains.
1. Unit trains of Coal, grain, oil, iron ore, pipe line, and to a lesser extent intermodal all share common characteristics.
2. They are all either full cars or empty tare weight cars throughout the train.
3. Weight of each car for a specific train is nominally the same.
4. Normal hearing of a train allows observer to determine if a unit train.
5. The lack of the usual rattling of a mixed train is usually only on none or just a few cars for unit trains.
It may be the triple valves on unit trains do not cause many flat wheels ? The ECP appears to reduce triple valve failures of individual cas. So if mixed trains had ECP then maybe there would be much fewer flat wheels which could dramatically reduce wheel changes ? Since many unit trains are private cars there is not incentative of freigh RRs to require ECP on private car trains. Their repair costs may be a profit center for the RRs ?
.Along that train of thought maybe the RR owned cars might give more bang for the buck ?
ECP may offer a reduction of stopping distance, but most of the time - who cares?
Would you spend an extra 10% on an automobile that had special equipment that allowed you to stop just that much faster and extended the life of your brakes and tires by some amount?
Or would you settle for planning ahead as you do now and being able to stop in the current distances? Do you spend so much on brake shoes/pads and tires that the extended life would pay for the extra cost of the fancy system?
ECP may somewhat increase capacity slightly on capacity constrained lines - but if a line only entertains a few trains a day, that's no advantage. If a line is signalled for a certain speed and train spacing, it doesn't really make a difference.
Maybe after PTC is fully implemented on capacity contrained lines, allowing slightly closer train spacing...
M636CEven if ECP does nothing to reduce emergency stopping distances, it might result in fewer cars derailing in an emergency brake application since the influence of longitudinal train action ir removed from the equation. Since derailments of oil trains is the problem to be avoided, ECP braking can only help.
tree68 ECP may offer a reduction of stopping distance, but most of the time - who cares? Would you spend an extra 10% on an automobile that had special equipment that allowed you to stop just that much faster and extended the life of your brakes and tires by some amount? Or would you settle for planning ahead as you do now and being able to stop in the current distances? Do you spend so much on brake shoes/pads and tires that the extended life would pay for the extra cost of the fancy system?
Suppose this car needed a dealer service every six months which you had to pay for, but by buying the special equipment this stretched out to every two years with the same cost per servicing.
And you found that you could get where you were going consistently in 75% of the time you took without the special equipment.
Would you think twice?
Suppose that in the case of unit coal trains being able to run faster allows one more return trip per week, say nine rather than eight, your return on investment has gone up 12.5%.
On a couple of occasions on different systems, I've been driving alongside empty ECP coal trains on a parallel road where the road and rail speed limits were similar and watched as the empty coal trains accelerated away from a restriction quickly (not having to wait for the final cars to release) and drew well away from me while I was driving slightly above the speed limit.
In both cases, the locomotives were new and their speed indicators probably read low because of new slightly oversize wheels...
I can't think of any cases where the same occurred with Westinghouse trains.
The higher speed and greater availability do count...
M636C tree68 ECP may offer a reduction of stopping distance, but most of the time - who cares? Would you spend an extra 10% on an automobile that had special equipment that allowed you to stop just that much faster and extended the life of your brakes and tires by some amount? Or would you settle for planning ahead as you do now and being able to stop in the current distances? Do you spend so much on brake shoes/pads and tires that the extended life would pay for the extra cost of the fancy system? Suppose this car needed a dealer service every six months which you had to pay for, but by buying the special equipment this stretched out to every two years with the same cost per servicing. And you found that you could get where you were going consistently in 75% of the time you took without the special equipment. Would you think twice? Suppose that in the case of unit coal trains being able to run faster allows one more return trip per week, say nine rather than eight, your return on investment has gone up 12.5%. On a couple of occasions on different systems, I've been driving alongside empty ECP coal trains on a parallel road where the road and rail speed limits were similar and watched as the empty coal trains accelerated away from a restriction quickly (not having to wait for the final cars to release) and drew well away from me while I was driving slightly above the speed limit. In both cases, the locomotives were new and their speed indicators probably read low because of new slightly oversize wheels... I can't think of any cases where the same occurred with Westinghouse trains. The higher speed and greater availability do count... M636C
M636C,
Do they use derailment sensors on the car trucks of the ECP-equipped trains in Australia?
M636CSuppose that in the case of unit coal trains being able to run faster allows one more return trip per week, say nine rather than eight, your return on investment has gone up 12.5%.
Methinks this is where the ROI is - on unit trains. With loose car railroading, the "who cares" factors in. I've read that for many customers, it's not the speed with which the load arrives, it's the consistency. The length of the trips makes a difference, too.
If ECP can do something about terminal dwell, then your 75% faster factors in. Otherwise, the car just gets to the yard that much faster - so it can sit or otherwise be processed.
And speed has less to do with ECP and more to do with the capabilities of the track over which the trains run. That new, fancy brake system in my personal vehicle won't get me to where I'm going in 75% of the time unless the state decides to raise the speed limits. And if I'm running a little 4 cylinder engine in my Rolls Kanardly, it doesn't make any difference how quickly the brakes release.
I'm sure ECP will have its day - probably when PTC increases capacity.
tree68 I'm sure ECP will have its day - probably when PTC increases capacity.
And when pigs get airborne with their own aerodynamics and propulsion.
Euclid M636C, Do they use derailment sensors on the car trucks of the ECP-equipped trains in Australia?
I've never seen a derailment sensor on any freight car truck...
Lots of empty/loaded detectors, but that's it.
In my statements earlier I was assuming the automatic feature of an emergency application following a break in the air pipe would initiate braking on all cars before and after the break instantaneously, reducing the run in and force on the derailed cars from the following cars still on the track.
While this automatic braking would also occur with a conventional train, the reduction in delay for the braking to take effect on the following cars should reduce damage in a derailment.
tree68 M636C Suppose that in the case of unit coal trains being able to run faster allows one more return trip per week, say nine rather than eight, your return on investment has gone up 12.5%. Methinks this is where the ROI is - on unit trains. With loose car railroading, the "who cares" factors in. I've read that for many customers, it's not the speed with which the load arrives, it's the consistency. The length of the trips makes a difference, too. If ECP can do something about terminal dwell, then your 75% faster factors in. Otherwise, the car just gets to the yard that much faster - so it can sit or otherwise be processed. And speed has less to do with ECP and more to do with the capabilities of the track over which the trains run. That new, fancy brake system in my personal vehicle won't get me to where I'm going in 75% of the time unless the state decides to raise the speed limits. And if I'm running a little 4 cylinder engine in my Rolls Kanardly, it doesn't make any difference how quickly the brakes release. I'm sure ECP will have its day - probably when PTC increases capacity.
M636C Suppose that in the case of unit coal trains being able to run faster allows one more return trip per week, say nine rather than eight, your return on investment has gone up 12.5%.
All of my arguments are based on fitting ECP to unit trains, partly because that is all I have any experience with.
Many of the Hunter Valley unit coal trains make a return trip in 24 hours or less.
Those in Queensland generally run further with longer journeys.
In the Hunter Valley, the trains are all hopper cars with automatically triggered air operated bottom doors and the trains move continuously through both the loader and unloaders. Unloading takes about two hours for 80 cars carrying 100 tonnes (about 110 US tons) each. There are about ten separate unloaders.
Recently five storage tracks were built for loaded trains to allow for delay at the unloaders without tying up the main lines.
A lot of the journey time for a freight train is involved in stopping at junction points or at signals while following other trains. ECP trains and conventional trains run interspersed with eachother. Being able to accelerate from a signal check more quickly using the power you already have reduces the delay for following trains regardless of the brakes they use.
I'm sure you've experienced the "compression effect" driving on a freeway where long after some event caused a car to brake, following cars slow and speed up again. On double track automatic signalled track (which makes up a lot of the Australian coal routes) ECP brakes reduce delays to following trains. In Queensland where a lot of the network is electrified, this effect is greater still.
So in the case of unit trains, I believe ECP brakes reduce journey time without the top speeds needing to be raised.
blue streak 1 As far as this poster can see the jury is still out on ECP. However maybe it needs to be looked at in a different way. It may be mixed freight trains need ECP much more than unit trains. 1. Unit trains of Coal, grain, oil, iron ore, pipe line, and to a lesser extent intermodal all share common characteristics. 2. They are all either full cars or empty tare weight cars throughout the train. 3. Weight of each car for a specific train is nominally the same. 4. Normal hearing of a train allows observer to determine if a unit train. 5. The lack of the usual rattling of a mixed train is usually only on none or just a few cars for unit trains. It may be the triple valves on unit trains do not cause many flat wheels ? The ECP appears to reduce triple valve failures of individual cas. So if mixed trains had ECP then maybe there would be much fewer flat wheels which could dramatically reduce wheel changes ? Since many unit trains are private cars there is not incentative of freigh RRs to require ECP on private car trains. Their repair costs may be a profit center for the RRs ? .Along that train of thought maybe the RR owned cars might give more bang for the buck ?
I would agree that manifest trains, with mixed equipment types might benefit more from ECP. It would aid in controlling slack for trains that have a lot of long/cushioned drawbars. Especially when they want to build them 9000 feet or more.
M636C Euclid M636C, Do they use derailment sensors on the car trucks of the ECP-equipped trains in Australia? I've never seen a derailment sensor on any freight car truck... Lots of empty/loaded detectors, but that's it. In my statements earlier I was assuming the automatic feature of an emergency application following a break in the air pipe would initiate braking on all cars before and after the break instantaneously, reducing the run in and force on the derailed cars from the following cars still on the track. While this automatic braking would also occur with a conventional train, the reduction in delay for the braking to take effect on the following cars should reduce damage in a derailment. M636C
jeffhergert blue streak 1 It may be the triple valves on unit trains do not cause many flat wheels ? The ECP appears to reduce triple valve failures of individual cas. So if mixed trains had ECP then maybe there would be much fewer flat wheels which could dramatically reduce wheel changes ? Since many unit trains are private cars there is not incentative of freigh RRs to require ECP on private car trains. Their repair costs may be a profit center for the RRs ? .Along that train of thought maybe the RR owned cars might give more bang for the buck ? I would agree that manifest trains, with mixed equipment types might benefit more from ECP. It would aid in controlling slack for trains that have a lot of long/cushioned drawbars. Especially when they want to build them 9000 feet or more. Jeff
blue streak 1 It may be the triple valves on unit trains do not cause many flat wheels ? The ECP appears to reduce triple valve failures of individual cas. So if mixed trains had ECP then maybe there would be much fewer flat wheels which could dramatically reduce wheel changes ? Since many unit trains are private cars there is not incentative of freigh RRs to require ECP on private car trains. Their repair costs may be a profit center for the RRs ? .Along that train of thought maybe the RR owned cars might give more bang for the buck ?
I'm not sure why general freight trains would benefit more from ECP.
The car utilisation is much lower and the return on investment would take longer to occur since the brakes and wheels and couplers and draft gear will last longer on individual cars.
The cost would be higher since virtually all the freight cars in North America would have to be fitted with ECP before it could be used in general freight trains and the introduction date would move so far right to be out of sight.
However, a unit train can start using ECP once one rake of cars (say 100) have been fitted and compatible locomotives are available. Most recent locomotive have brake controllers suitable for ECP. just needing the connecting cables to be fitted.
There may be more benefits in fitting general freight but the cost will be higher and timescales will be longer.
M636C jeffhergert blue streak 1 It may be the triple valves on unit trains do not cause many flat wheels ? The ECP appears to reduce triple valve failures of individual cas. So if mixed trains had ECP then maybe there would be much fewer flat wheels which could dramatically reduce wheel changes ? Since many unit trains are private cars there is not incentative of freigh RRs to require ECP on private car trains. Their repair costs may be a profit center for the RRs ? .Along that train of thought maybe the RR owned cars might give more bang for the buck ? I would agree that manifest trains, with mixed equipment types might benefit more from ECP. It would aid in controlling slack for trains that have a lot of long/cushioned drawbars. Especially when they want to build them 9000 feet or more. Jeff I'm not sure why general freight trains would benefit more from ECP. The car utilisation is much lower and the return on investment would take longer to occur since the brakes and wheels and couplers and draft gear will last longer on individual cars. The cost would be higher since virtually all the freight cars in North America would have to be fitted with ECP before it could be used in general freight trains and the introduction date would move so far right to be out of sight. However, a unit train can start using ECP once one rake of cars (say 100) have been fitted and compatible locomotives are available. Most recent locomotive have brake controllers suitable for ECP. just needing the connecting cables to be fitted. There may be more benefits in fitting general freight but the cost will be higher and timescales will be longer. M636C
Train Handling.
Euclid M636C I agree that the simultaneous application of ECP brakes would give an advantage over conventional air brakes in reducing the number of cars that enter a pileup resulting from a derailment. Even though that quicker stopping advantage of ECP is only a matter of 4-6 seconds; that is a major advantage in the timespan of a pileup. Derailment sensors can add to that ECP advantage by eliminating the delay between the first wheelset to leave the rails, and the moment the pileup begins. Derailment sensors can add a similar advantage with conventional air brakes, but ECP offers the communications cable to communicate the derailment sensor signal to the controller that sets an “Emergency” application. Without the instant communication of the cable, derailment sensors with conventional air brakes typically work to dump the air on the first car to derail, and being the typical sequential application. The potential slack run-in associated with this sequential “Emergency” application might actually trigger a pileup in a derailment that might otherwise not progress beyond the derailed-dragging phase. With conventional air brakes, the pileup has to begin before the brake application can begin. With ECP + derailment sensors, the application begins when the first wheelset derails which might be considerably earlier than the commencement of the pileup. In some cases, the earlier application of ECP can actually prevent the pileup from beginning, as well as reducing the pileup if it does begin.
I agree with every point here.
As I've said, I've not seen a derailment detector on a car.
There are fixed "dragging equipment detectors" which consist of cast iron bars beside and between the rails which wil be broken by a derailed wheel and send an alarm to the train crew and train controller.
Derailments are not a really big problem in Australia, certainly not with unit trains, although clearing up a loaded iron ore train which derails in a deep rock cutting is a real challenge.
Heavy rain undermining track is a problem. We had two bad incidents, a block train of concentrated sulphuric acid derailed the locomotive and thirty cars, all of which were on their sides and one tank car lost its load into the local river....
And an intermodal train rolled onto its side in remote Western Australia following heavy rain.
But derailment detectors of any kind don't help once the locomotives are lying on their side in the dirt.
In Australia the track is owned by the state governments and the main lines are maintained by the Federal government (what could possibly go wrong, I hear you say!).
One result of this is strict control of axle loading: Intermodal trains are allowed 22 long (2240lb) tons, grain is allowed 23 long tons and coal is allowed 25 tons or 30 tons on specific routes with heavier rail.
When the Federal government took over, a massive campaign to improve track took place with concrete ties on all main lnes and the replacement of automatic semaphore signalling (about a hundred years old) with LED light signals.
In some places, only a third of the ties were able to be pulled out without crumbling to dust. The ballast was basically dirt with a covering of crushed rock. Serious ballast cleaning is still taking place, but the removal of temporary speed restrictions, particularly in summer for fear of heat kinks has saved hours on the main intercity trips.
But I believe that limiting track loadings and improving the infrastructure has contributed to a significant reduction in "random" derailments.
M636C Euclid M636C I agree that the simultaneous application of ECP brakes would give an advantage over conventional air brakes in reducing the number of cars that enter a pileup resulting from a derailment. Even though that quicker stopping advantage of ECP is only a matter of 4-6 seconds; that is a major advantage in the timespan of a pileup. Derailment sensors can add to that ECP advantage by eliminating the delay between the first wheelset to leave the rails, and the moment the pileup begins. Derailment sensors can add a similar advantage with conventional air brakes, but ECP offers the communications cable to communicate the derailment sensor signal to the controller that sets an “Emergency” application. Without the instant communication of the cable, derailment sensors with conventional air brakes typically work to dump the air on the first car to derail, and being the typical sequential application. The potential slack run-in associated with this sequential “Emergency” application might actually trigger a pileup in a derailment that might otherwise not progress beyond the derailed-dragging phase. With conventional air brakes, the pileup has to begin before the brake application can begin. With ECP + derailment sensors, the application begins when the first wheelset derails which might be considerably earlier than the commencement of the pileup. In some cases, the earlier application of ECP can actually prevent the pileup from beginning, as well as reducing the pileup if it does begin. I agree with every point here. As I've said, I've not seen a derailment detector on a car. There are fixed "dragging equipment detectors" which consist of cast iron bars beside and between the rails which wil be broken by a derailed wheel and send an alarm to the train crew and train controller. Derailments are not a really big problem in Australia, certainly not with unit trains, although clearing up a loaded iron ore train which derails in a deep rock cutting is a real challenge. Heavy rain undermining track is a problem. We had two bad incidents, a block train of concentrated sulphuric acid derailed the locomotive and thirty cars, all of which were on their sides and one tank car lost its load into the local river.... And an intermodal train rolled onto its side in remote Western Australia following heavy rain. But derailment detectors of any kind don't help once the locomotives are lying on their side in the dirt. In Australia the track is owned by the state governments and the main lines are maintained by the Federal government (what could possibly go wrong, I hear you say!). One result of this is strict control of axle loading: Intermodal trains are allowed 22 long (2240lb) tons, grain is allowed 23 long tons and coal is allowed 25 tons or 30 tons on specific routes with heavier rail. When the Federal government took over, a massive campaign to improve track took place with concrete ties on all main lnes and the replacement of automatic semaphore signalling (about a hundred years old) with LED light signals. In some places, only a third of the ties were able to be pulled out without crumbling to dust. The ballast was basically dirt with a covering of crushed rock. Serious ballast cleaning is still taking place, but the removal of temporary speed restrictions, particularly in summer for fear of heat kinks has saved hours on the main intercity trips. But I believe that limiting track loadings and improving the infrastructure has contributed to a significant reduction in "random" derailments. M636C
Euclid The main point of derailment detectors is to set the brakes as early as possible. The type that are completely mechanical and used with conventional air brakes, must dynamite the brakes if they detect a derailment. That has the potential to perturb the derailed-dragging car enough to cause a pileup, whereas, if left to drag without the “Emergency” application, the train may just stop for some other reason, resulting in the derailment being discovered. Last summer, a tank car load of acrylonitrile caught fire on the CSX in Tennessee. As it was later learned, that car had been derailed and dragging for NINE MILES. A derailment detector would have stopped the train as soon as the car derailed, and thus prevented the eventual fire that started from friction in the derailed truck. The benefit of combining derailment detectors with ECP is that there need not be an emergency application initiated upon derailment. A lighter application could be made in order to not upset the fragile equilibrium of a derailed-dragging car. Even if an “Emergency” application were initiated, it would apply simultaneously throughout the train, and thus reduce the risk of slack run-in perturbing the derailed-dragging car into causing a pileup.
I'm certainly not opposed to derailment detectors, I've just never seen one....
Do many US freight cars carry these detectors?
It would seem to be a good idea to equip new oil tank wagons with these devices as a standard fit, given the likelihood of avoiding some derailment accidents.
Of course, the Lac Megantic disaster would not have been avoided by a derailment detector, since by the time the derailment occured, the unmanned train was travelling at a high speed and by definition was out of control.
The combination of ECP braking and derailment detectors on all cars of a block oil train would have positive results in the case of rails breaking under the train or an axle bearing failure. This might be regarded as justifiable on block oil trains and other tank cars of hazardous substances. Non tank cars carrying Ammonium Nitrate, preferably not mixed with oil tank cars, might be worth fitting.
But for general freight trains, unless all cars were fitted with derailment detectors, they will only work if a detector fitted car derails. A car with a detector could run for miles a few cars away from a derailed car without the actuator working.
Probably the biggest objection to ECP is the "electronic control" part. I would guess that the railroads view the weak link as the connections in the electrical control line through the train. With a ore or maybe a coal train, that only couples, uncouples once or twice a trip, its not that bad. But with other types of trains there will be more frequent coupling and uncoupling of the signal line.
Think about a hump yard. The electrical connection needs to stay reliable coupled but when the car is uncoupled, it has to part automatically without damage. The connection has to be reliable enough that if it is uncoupled and then sits in a track for 3 months, exposed, without coupling into another car, it can at a moments notice be used again.
Not saying it isn't possible, just saying I think that was percieved by the railroads as the weak spot in the system. Unit coal or ore trains might stay together (they don't always, only those on balloon loop loaders and unloaders. All the other trains (unit or otherwise) couple and uncouple frequently and the connection reliability is a concern.
Dave H. Painted side goes up. My website : wnbranch.com
M636C Euclid The main point of derailment detectors is to set the brakes as early as possible. The type that are completely mechanical and used with conventional air brakes, must dynamite the brakes if they detect a derailment. That has the potential to perturb the derailed-dragging car enough to cause a pileup, whereas, if left to drag without the “Emergency” application, the train may just stop for some other reason, resulting in the derailment being discovered. Last summer, a tank car load of acrylonitrile caught fire on the CSX in Tennessee. As it was later learned, that car had been derailed and dragging for NINE MILES. A derailment detector would have stopped the train as soon as the car derailed, and thus prevented the eventual fire that started from friction in the derailed truck. The benefit of combining derailment detectors with ECP is that there need not be an emergency application initiated upon derailment. A lighter application could be made in order to not upset the fragile equilibrium of a derailed-dragging car. Even if an “Emergency” application were initiated, it would apply simultaneously throughout the train, and thus reduce the risk of slack run-in perturbing the derailed-dragging car into causing a pileup. I'm certainly not opposed to derailment detectors, I've just never seen one.... Do many US freight cars carry these detectors? It would seem to be a good idea to equip new oil tank wagons with these devices as a standard fit, given the likelihood of avoiding some derailment accidents. Of course, the Lac Megantic disaster would not have been avoided by a derailment detector, since by the time the derailment occured, the unmanned train was travelling at a high speed and by definition was out of control. The combination of ECP braking and derailment detectors on all cars of a block oil train would have positive results in the case of rails breaking under the train or an axle bearing failure. This might be regarded as justifiable on block oil trains and other tank cars of hazardous substances. Non tank cars carrying Ammonium Nitrate, preferably not mixed with oil tank cars, might be worth fitting. But for general freight trains, unless all cars were fitted with derailment detectors, they will only work if a detector fitted car derails. A car with a detector could run for miles a few cars away from a derailed car without the actuator working. M636C
Posted by blue streak 1 on Friday, February 19, 2016 8:53 PM
Could it be that the only way to maintain a good electrical connection would be for the connection become part of the air hose connection ? Then a car knocker when hooking up the air hoses would have to spray contact cleaner on the electrical connection part. UGH ! !.
There actually is an electrical connector that would be analogous to the glad hand in that it would have to be "made" but would break easily. I'm using a small version of the connectors (the Anderson "PowerPole") for my ham radios. I'll let you look them up.
Assuming that appropriate stress relief could be arranged, I'd suspect they would work.
I'm only worried about a two conductor plug for supplying power to my radios. If more electrical conductors were needed, it could probably be arranged, although it may be possible to code the braking signal on top of the supply voltage.
Properly designed, changing out a cable wouldn't be any more difficult than changing out an air hose. They could easily be designed with appropriate metals to combat corrosion.
tree68 There actually is an electrical connector that would be analogous to the glad hand in that it would have to be "made" but would break easily. I'm using a small version of the connectors (the Anderson "PowerPole") for my ham radios. I'll let you look them up.
Those type connections are used for connecting external batteries for starting cars in racing. Would have to be toally reengineered for a rail use and as they exist would experience a high level of wear, as well as weather problems over time.
Electrical connections and unattended disconnection of them sould like they have a high potential for recurring failure in the railroad world.
blue streak 1Could it be that the only way to maintain a good electrical connection would be for the connection become part of the air hose connection ? Then a car knocker when hooking up the air hoses would have to spray contact cleaner on the electrical connection part.
It's worse than that. Remember that this connection carries 220V power, so any sideways or rotating engagement could not project forward to where any errant hand or other body part would contact it -- might even need to be a safety shutter over the contacts. Then you'd have to 'make' them firmly enough not to induce spark erosion if the connection vibrates. I would suspect the car-knocker's solution would be to use some kind of dielectric grease for the 'surround' lubrication, rather than blowing it off clean.
Another consideration has to be the number of terminations and potential areas of QoS loss with all the connections in what amounts to a data network. I suspect that the BITE equipment in the various valves and controllers of the brake system can work with this... but probably only if explicitly designed recognizing the problem.
My understanding was that a very large amount of thought and effort had gone into the current 'standard' for the Freight-Mate connectors and the design of the 'pigtails' back to the junction boxes on the car frames. These are rigged so that if anything hangs up the pigtail pulls loose safely at the box end, and then can be easily field-replaced ... or so goes the theory. I would think that if industry could have evolved either a modern Tomlinson approach to the electrical conductors, or incorporate them as noted into the air-hose gladhand, for loose-car-compatible operation or for blocks of cars intended to be run when necessary in normal service, the approach would have been either better tried or better documented. (Passenger railroading is distinctly different...)
BaltACDWould have to be totally reengineered for a rail use...
No doubt in my mind that they'd have to be ruggedized and then some. The cable would probably have to have a strengthening cable within it which would be tied to both the plug and the car as well.
The main thing is that there is no latch, as such, so the two connectors could easily be pulled apart, and that they are sexless.
On the other hand, if the ruggedized version was anything like the HEP cables we use, what a pain...
tree68 BaltACD Would have to be totally reengineered for a rail use... No doubt in my mind that they'd have to be ruggedized and then some. The cable would probably have to have a strengthening cable within it which would be tied to both the plug and the car as well. The main thing is that there is no latch, as such, so the two connectors could easily be pulled apart, and that they are sexless. On the other hand, if the ruggedized version was anything like the HEP cables we use, what a pain...
BaltACD Would have to be totally reengineered for a rail use...
I think these are the ones we use in Australia...
http://www.uic.org/cdrom/2001/wcrr2001/pdf/sessions/1_6/465.pdf
See figure 4. It is sexless, has a latch but is designed to survive being pulled apart.
As far as I've heard there have been no problems.
There is apparently a radio alternative illustrated (figure 3). While I spent much of my wasted youth looking at that exact type of ore car from that angle, I know nothing about radio ECP brakes and that company uses the standard connectors on their cables now.
There are details on pages 19 and 20 of
http://www.nyab.com/media/nyab_1/documents_1/technical/instructionpamphletsip/IP-237.pdf
Nothing needs to be developed. It's all there waiting to be purchased from well established USA companies.
It's been used for 11 years in Australia in daily service with no particular problems, and I don't believe our crews are any more gentle than those in the USA.
Euclid The only critical feedback that I have ever heard about ECP brakes in the U.S. testing experience has been about the connector problem. Here is a USDOT report from 1999 showing a connector on pages 17 and 18. http://ntl.bts.gov/lib/42000/42700/42740/ord9907.pdf It says that the earlier connector design had experienced problems during testing on Conrail, and had been redesigned to overcome those problems, and the new design is shown on page 18. I conclude that the problem has been solved. Are these connectors made to decouple by the pull of the cars when cars are uncoupled and separated? Or must an operator depress the spring button, and pull the two connectors apart by hand?
All the connectors in Australia are the AAR standard design.
I believe the connectors are designed to pull apart but I would expect that they would normally be disconnected manually by depressing the buttons.
I note that positive locking was one of the deficiencies raised in the USDOT report.
Of course, the trains don't get pulled apart very often. In the Hunter Valley, a train is given a number, painted on a small metal plate displayed on the nose of the lead locomotive, so the actual rake of cars can be identified, rather than the train's numerical identity in the timetable. Service tracks are provided so that empty trains can be inspected end to end while the locomotives can be refuelled and sanded still coupled to the train.
I expect that the connectors that see the most use would be between the locomotives and the train and between locomotives and I'd expect that these would be disconnected the same way as MU cables between locomotives.
The GPS-assisted Herzog ballast trains have electrical connectors between the cars. They uncouple themselves when you cut the train. They look similar to the ones in the report Bucyrus cites.
EuclidHere is a USDOT report from 1999 showing a connector
Some indication of scale would have been nice in the picture - as it is, one can't tell if it's a half inch across or 6" (not Euc's fault).
This image shows that a little better:
tree68 Euclid Here is a USDOT report from 1999 showing a connector Some indication of scale would have been nice in the picture - as it is, one can't tell if it's a half inch across or 6" (not Euc's fault). This image shows that a little better:
Euclid Here is a USDOT report from 1999 showing a connector
There were similar views in the NYAB operator manual I posted a link to...
Of course, I can see the real thing on trains with an empty and a loaded passing East Maitland every fifteen minutes each and more than half the trains having ECP, so I hadn't considered the scale as being important.
The point is that you don't have to find a seventeen year old photo, the connectors and the rest of the system are in daily use, everything is off the shelf ready to use and all that has to happen is to decide to use it.
Perhaps a repeat of my post of last June touching on some aspects of the ECP session at the Heavy Haul Conference in Perth might be of help here.
Some interesting takeaways from sessions at the recent international heavy haul conference. In a conversation with Gary Wolf, probably the best independent derailment investigator in North America, he felt that the advantage of ECP brakes in emergency is so small that he felt the mandate was totally unjustified. This was further reinforced by a paper from China that, among other things compared emergency stopping distances of ECP and conventional braked trains for a variety of train sizes and speeds. On the graphs shown, the distance difference was almost imperceptible.
In a bit of a surprise they showed a graph (that was not in the published paper) that seemed to show that longitudinal forces were higher in the ECP trains in emergency braking. Unfortunately the graphs shown had Chinese legends and the author was unable to understand questions in English, so that's a bit of a mystery.
The chairperson of the AAR air brake committee made a presentation on the state of the art in ECP. One of the issues related to unreliability of the system is cross talk between trains. Yes I know it's a wire line system, but when passing train A can hear messages leaking from train B and vice versa. If a locomotive detects a message from a car not in its consist it will initialize a penalty application. The spec is being revised so messages now include train number as well as car number. This is said to mitigate but not eliminate the problem as crossover messages will be ignored but will still consume coms capacity and may result in a time out penalty application. There have also been some issues with the connectors as they get older and wear, resulting in moisture penetration and ground fault failures. There is a search for a new connector.
It was noted that the committee feels that the tank car mandate will need to be an overlay resulting in dual systems on board the affected cars. The current cost estimate is in excess $6000 per car.
Sharma & Associates presented some work they did on predicting the probable number of punctures in various tank car derailment scenarios. They noted that there were so many variables and a wide range of potential values for each that an exact value was impossible to predict. The study used chaos theory ( noting that derailments are chaotic events) to estimate a most likely result but noted for any given derailment an exact value was impossible to determine.
Buslist Perhaps a repeat of my post of last June touching on some aspects of the ECP session at the Heavy Haul Conference in Perth might be of help here. Some interesting takeaways from sessions at the recent international heavy haul conference. In a conversation with Gary Wolf, probably the best independent derailment investigator in North America, he felt that the advantage of ECP brakes in emergency is so small that he felt the mandate was totally unjustified. This was further reinforced by a paper from China that, among other things compared emergency stopping distances of ECP and conventional braked trains for a variety of train sizes and speeds. On the graphs shown, the distance difference was almost imperceptible. In a bit of a surprise they showed a graph (that was not in the published paper) that seemed to show that longitudinal forces were higher in the ECP trains in emergency braking. Unfortunately the graphs shown had Chinese legends and the author was unable to understand questions in English, so that's a bit of a mystery. The chairperson of the AAR air brake committee made a presentation on the state of the art in ECP. One of the issues related to unreliability of the system is cross talk between trains. Yes I know it's a wire line system, but when passing train A can hear messages leaking from train B and vice versa. If a locomotive detects a message from a car not in its consist it will initialize a penalty application. The spec is being revised so messages now include train number as well as car number. This is said to mitigate but not eliminate the problem as crossover messages will be ignored but will still consume coms capacity and may result in a time out penalty application. There have also been some issues with the connectors as they get older and wear, resulting in moisture penetration and ground fault failures. There is a search for a new connector. It was noted that the committee feels that the tank car mandate will need to be an overlay resulting in dual systems on board the affected cars. The current cost estimate is in excess $6000 per car. Sharma & Associates presented some work they did on predicting the probable number of punctures in various tank car derailment scenarios. They noted that there were so many variables and a wide range of potential values for each that an exact value was impossible to predict. The study used chaos theory ( noting that derailments are chaotic events) to estimate a most likely result but noted for any given derailment an exact value was impossible to determine.
I was at the Heavy Haul Conference in Perth last June...
Where did you post last June - not on this thread which is much more recent.....
I didn't go to the Chinese presentation of ECP braking, partly because I felt (and still feel) that we in Australia would be way ahead of China in the application of ECP braking and I felt (and still feel) that the advantages of ECP braking are so well established as to not need academic papers in support.
I had just spent a full week in the Pilbara where most of the trains are ECP equipped. I must have seen thirty ECP trains pass eachother at speed on double track or more slowly in sidings on single track, and not one suffered from an unexpected emergency application of the brakes while I was watching.
Did you take up the offer of the side trip to Port Hedland to inspect Fortescue Metals which run an all ECP operation. Even their ballast hoppers have ECP brakes.
I have been watching ECP trains pass in the Hunter Valley and in Central Queensland, where many sections of line have four or three tracks and the main lines are double track for the eleven years that ECP trains have been operating and I have never heard of, let alone seen a brake application initiated by crosstalk from the cables. I myself must have seen hundreds of empty and loaded ECP trains pass eachother at both high and low speeds on normally spaced double tracks. Clearly these trains did not have any new software to prevent crosstalk, certainly not back in 2005, and my feeling is that the probability of this occurring must be very small, since I've never heard of it happening on any of the systems using ECP in Australia. Where was this problem experienced, and how often has it occurred?
However, a colleague who was with me at the conference is fluent in both Cantonese and Mandarin, and if you can give me the Title of the paper and the name of the Presenter, I might be able to get details of the offending diagram translated, and we can know for sure whether the forces are higher or lower with ECP braking. He has good contacts with the organisers of the conference, and might be able to get a copy of the slide from them.
I don't understand the emphasis on emergency braking. ECP is significantly better in normal service braking that in general occurs much more often than emergency braking, and improved service braking is where the improvements in throughput and savings in operating costs come in.
Block oil trains would be a good place to start using ECP braking, since the tank cars are almost all owned by leasing companies and converting the tank car fleet would cost the railroads very little, even if the tank cars were all dual equipped.
Have any oil tank car derailments occurred in a scenario where greatly improved emergency braking would have avoided the problem? Certainly where a rail has broken, the emergency application occurs after the damage has been done.
In earlier posts I've suggested that the faster application of brakes on the trailing section of the train AFTER a derailment would reduce the damage, and this feature of ECP braking might not be reflected in a theoretical calculation of braking distance compared to a Westinghouse system.
But it seems to me that the US railroads are "cherry picking" data to support the conclusion they have already reached that ECP braking poses insurmountable problems.
Meanwhile, the railroads in the rest of the world are fitting ECP brakes conforming to AAR standards using their own money simply because they expect to get an early return on their investment.
If you look hard enough, you'll probably be able to find some possible technicality that might cause problems.
But in Australia, the ECP trains just keep running, day in day out, with no cross talk, no unexpected brake applications, running faster and saving money on wheels and brakes.
M636CI was at the Heavy Haul Conference in Perth last June... Where did you post last June - not on this thread which is much more recent.....
Rather different views on ECP in Australia and likely even the conference in Perth by two folks in the field.
M636C I don't understand the emphasis on emergency braking. ECP is significantly better in normal service braking that in general occurs much more often than emergency braking, and improved service braking is where the improvements in throughput and savings in operating costs come in. Have any oil tank car derailments occurred in a scenario where greatly improved emergency braking would have avoided the problem? Certainly where a rail has broken, the emergency application occurs after the damage has been done. But it seems to me that the US railroads are "cherry picking" data to support the conclusion they have already reached that ECP braking poses insurmountable problems.
1) Simultaneous application throughout the train.
2) Quicker stopping.
M636c, would I be correct in assuming that the connector cables pull apart automatically just like air hoses when cars are uncoupled? If yes, and combined with the dual ECP/mechanical triple valve setup discussed earlier that would solve interoperability issues, and the successes in Australia and on Cartier would suggest a lack of sensitivity to hot/cold/dry/wet conditions. Sounds proven to me, now the only remaining issue preventing widespread North American implementation is the ultra-conservative attitude of Class I upper management.
SD70M-2Dude M636C, would I be correct in assuming that the connector cables pull apart automatically just like air hoses when cars are uncoupled? If yes, and combined with the dual ECP/mechanical triple valve setup discussed earlier that would solve interoperability issues, and the successes in Australia and on Cartier would suggest a lack of sensitivity to hot/cold/dry/wet conditions. Sounds proven to me, now the only remaining issue preventing widespread North American implementation is the ultra-conservative attitude of Class I upper management.
M636C, would I be correct in assuming that the connector cables pull apart automatically just like air hoses when cars are uncoupled? If yes, and combined with the dual ECP/mechanical triple valve setup discussed earlier that would solve interoperability issues, and the successes in Australia and on Cartier would suggest a lack of sensitivity to hot/cold/dry/wet conditions. Sounds proven to me, now the only remaining issue preventing widespread North American implementation is the ultra-conservative attitude of Class I upper management.
I've never actually seen them pulled apart but I believe the design does allow that.
They can be separated manually by depessing the spring loaded buttons on the latches, but these should also allow the connectors to pull apart without damage.
However, I belive that the Australian experience shows that unit trains can be progressively converted with little or no disruption to the remainder of the conventional traffic.
As an aside, the standard AAR connectors are used by all systems operating ECP in Australia, even those on different gauges where there is no possibility of interchange.
I think that if USA railroad managers had closely inspected the operating ECP trains in Australia last June they would have had to reconsider their position.
M636CI think that if USA railroad managers had closely inspected the operating ECP trains in Australia last June they would have had to reconsider their position.
I would opine that there are only two things that will cause US railroads to adopt ECP:
1. Government Regulation
2. Proving that ECP has an ROI sufficient to make it worth their while (ie, increasing the bottom line).
At this point, #1 hasn't come into play for general railroading, and #2 hasn't shown it's face or ECP would be delayed only for lack of parts.
I am so damn tired of this stupid posting interface kicking you out for hitting the wrong arrow key by mistake, after it throws you somewhere else in the post at random when you try to use italics or boldface. It doesn't appear to be machine- or even platform-specific, so I conclude it is either a bug or misconfiguration in the Kalmbach site code. Why can programmers not figure out how to program for actual people?
I suspect much of the objection by American railroads to ECP involves the great investment in 'stranded cost' proprietary equipment, systems, and associated maintenance and training to make even a limited change within current operating models. In my opinion, the net effect on safety is reduced, rather than improved, in a scenario where train-handling comes to depend on improved ECP performance that 'may or not' be present in an actual train; I believe this mirrors the same phenomenon during the long introduction of air brakes 'as mandated' in the early days of Government 'safety regulation' involving Lorenzo Coffin et al.
I also suspect there is a certain industry reluctance to be the 'early adopter' that pays all the costs for the learning and acceptance curves, and the initial prices before production and aftermarket bring the unit costs down and 'commoditize' many of the parts and standards. With reference to 'reading between the lines' in the posts regarding the Heavy Haul conference -- where were the Australian papers and commentary/questions on the Chinese presentation? Where are the non-manufacturer papers and discussions, even now, that make the right 'business cases' for ECP adoption (even in the absence of likely support or even toleration from the AAR or cognate organizations)?
I personally find it outright astounding that either WABTEC or NYAB hasn't issued a pointed position statement or white paper that clearly defines how their system does both service and emergency braking, and equally clearly deconvolves the confusion about 'emergency' and 'service' stopping time and distance in clear, unequivocal English sentences. That one document, coming from a verifiable and reasonably expert source, would close down most of the waste of time, money, and talent in the current 'mandate' furball/cluster.
imho.
M636C In earlier posts I've suggested that the faster application of brakes on the trailing section of the train AFTER a derailment would reduce the damage, and this feature of ECP braking might not be reflected in a theoretical calculation of braking distance compared to a Westinghouse system. M636C
EuclidWhat do you have in mind with regard to your above comment?
What I understood him to mean was that faster setup and action helps keep as much as possible of the trailing part of the train from 'running into' already-derailed cars that have come to a stop with the usual digging-into-the-ballast kind of alacrity, at most any rate in excess of what cars can achieve with braked steel wheels on steel rails (or even, as seen in the notorious 'tornado video' steel structure sliding on steel rails or on relatively smooth ties and ballast adjacent to rails...)
The differential braking concepts still, I think, apply, but this is a very different thing from either what M636C means or what buslist has said in previous posts on this general idea.
Some of this does hinge on the idea that as soon as derailed equipment starts to dig in it is desirable or even 'politically' (or legal-liability-avoiding) necessary to put the rear part of the train in emergency ASAP to lessen the magnitude of the pileup. This whether or not up to that point differential braking were being used to keep the derailed equipment from digging in. I think it can be easily established that current systems of ECP do NOT have the capability to modulate braking in the same way they do for service -- that is part of the reason I consider the actual emergency-brake distance and time difference between regular and ECP brakes to be so tiny -- and therefore when any part of the trailing consist has to go into 'maximum effort' braking to avoid further pileup, any attempt to control what the derailed equipment is doing via differential modulation will effectively end.
Much of the effect of very quick and positive braking of a consist following an embedding derailment can be achieved with multiple inline venting of a conventional brake pipe, at vastly lower cost. In my (not very humble in this context) opinion, the complaints that have been made about problems with practical implementation of such valves (including freezing under Canadian conditions of weather, design, and maintenance) can be overcome, or systems that directly address the problem can be designed that will work in normal railroaders' practice. Perhaps that ought to be at least an intermediate priority ... but of course it would probably become an excellent case study for 'good driving out better' in the evolution of train brake systems.
EuclidMy concept of differential braking retains the faster application advantage of ECP on the entire train, but withholds some of the braking force on the cars ahead of the derailment.
So does mine. I'm just pointing out where the differential braking attempt needs to be discarded and the throw-out-the-anchor type of emergency braking would start to take its place. In part this is because any developing derailment is going to part that communication/power line, and you MUST have the brakes in failsafe before that happens. Might as well be in mechanical emergency as be trying to modulate brakes that no longer 'hear' you or can respond electrically...
As I think both I and my father have argued previously, we think it is a 'better' idea to keep an ECP train in heavy service than in 'emergency', primarily to avoid the usual emergency-related further damage and derailment propensity. buslist and a couple of other actual industry participants disagree with this, and I for one do not even propose to suggest that this 'difference of opinion' means that they are 'wrong'. Note particularly here that my method of ECP control calls for some distributed 'backup' modulation and actuation method other than that from a patent 220V 'cable', so maintenance of some, even all necessary modulation for differential segment braking and wheelslide reduction is preserved even if cars twist enough to compromise the line or the train parts. Be sure that when yours does, too, that the previously-expressed concerns about crosstalk, false 'safety' or penalty applications, etc. are addressed...
EuclidRegarding the point of whether this is an “Emergency” application or a “Service” application, I do not entirely understand how these are distinguished in an ECP system.
If you read the technical documentation for either the NYAB or WABTEC system, you will get this. In a typical system the ability to 'big-hole' the pneumatic part of the system is retained, essentially 'downstream' of the modulating electric valve. Emergency then consists of full line pressure to the cylinders, the 'difference' in setup speed being only that the electric "bypass" valves all operate immediately, and a bit more positively via their actuators, than a sonically-activated triple will. In addition, the available air pressure in the trainline is 'full' at all times, so there may be some makeup to the main reservoirs as they supply the cylinders and thereby a higher cylinder pressure can be established earlier or reached 'at the limit'.
Modulated 'service' application, on the other hand, can use all the available ECP advantages, including different braking limit rates detected for car types or loadings. It also includes the inherent ability to use very heavy or quick application of the brakes without having to 'worry' that you'll have to 'live with the consequences of your actions' afterward until you can recharge the system enough to release the excessive set.
In any case, in my concept, the application is not triggered by the parting of the wire. It is triggered by a signal sent directly to the master controller by the affected derailment detector.
I am not saying otherwise in any respect. The 'parting of the wire' is the point at which either modulation and control power is lost to the trailing consist, or some or all the sensor input from that part of the consist becomes 'indeterminate', and while not in the disturbing sense of the Browns Ferry fire, this may be problematic if a short between the conductors compromises either the 'last known good' or 'emergency default' positions of the ECP brake valves, or compromises how those valves subsequently act under autonomous control or self-power.
The 'emergency' here would actuate not at the time the first detector activates, but at the time a loss-of-control event occurs (I think a direct parallel to the kind of issue buslist was describing, where any anomalous event in the wireline signal integrity causes an immediate 'penalty brake' to full halt for reset.) The issue is then whether subsequent reaction of the trailing brakes in your system goes directly to 'mechanical' full emergency release, or to a graceful-degrade failover of some sort in which some of the potential advantages of ECP control can be retained.
This application would be as quick as possible with ECP; on both sides of the derailment; but will follow the modulation program with some reduction of force in the cars ahead of the derailment.
The point I was making here is that it will not be 'as quick as possible with ECP' on the trailing part of a wireline-controlled system (you say you no longer have either RF or inductive control modality) - as soon as the signal integrity is lost to the trailing consist, you will at best be using some sort of AI or expert-system emergency self-modulation of that part of the brake system. Much more likely, you will be in full emergency at that point in an all-out effort to keep even one car from accordioning into what is soon to be a very substantial and stopped obstacle to the trailing cars.
Now, what happens to the brake application of the consist ahead of the derailed cars, especially as those cars may be dragged by their couplers and in fact may be starting themselves to overturn, is a separate issue. Here buslist et al. also think full emergency (to get the momentum of 'the inevitable' as low as possible before the rolling starts) is the most appropriate response to go to. The 'catch' here is that the derailment sensors on any of the cars in this section aren't providing you with 'additional information' you can use for the modulation decision, other than to give a heads-up and a record of how the actual derailing progressed over time. What you need are the differential draft-gear tension and extension sensors, and I have been tempted (although not very far, up to now!) to modulate the 'differential braking' so as to actually try to get a knuckle as close as possible to where the derailed cars are connected to the as-yet-underailed part of the train... then actually retard the braking rate to ensure that an underailed leading portion won't be run into, and perhaps further damaged or derailed, by whatever is 'known off the track' to enough extent to part the line. (Railroaders will be laughing hysterically at this point, but it does represent one of the branches that control theory reaches when this extent of brake modulation can be provided.)
EuclidI have not correctly stated my thoughts about modulation above. When I ruled out the wireless control for modulation, as I mentioned above, I ruled out modulation as well. I should not have used the term “modulated response” in my second paragraph. Instead, it would be a predetermined response of lower braking force on the leading cars compared to the maximum force response on the trailing cars. But it would be the same force throughout the stopping time. This predetermined response would be determined by the variety of train characteristics that I mentioned above.
This is a place where you and I wildly disagree.
Even my father's old system for Conrail circa 1988 'modulated' the train-brake application continuously over time, and he thought necessarily so, so as to avoid the then-significant problems that occurred with 'positive train control' brake application of the sort suitable for passenger or commuter consists when applied indiscriminately to a much longer freight with unpredictable makeup or braking characteristics.
In my opinion it would be completely pointless to even attempt doing stretch braking with two 'average' brake applications on two halves of a foundation-braked train, even if the physical brake action were continuously proportional and progressive (which it is certainly not!) You will very quickly have a systemic and increasing load (and remember it HAS to stay in tension; even a moment's compression or run-in means almost assured disaster) that will involve very substantial inertial mass backed up by a large amount of aggregate friction and contact area. So when the draft-gear travel goes out you will essentially have the whole force yanking on one of a very few couplers in the derailed portion of the train. And if the derailed portion decides to dig in, it will bring its considerable deceleration to bear on the leading coupler connection, which will snap something and result very quickly in 'divergence' of the now-unguided first car and probable establishment of accordioning.
In my opinion, we need a better (and more detailed) description of exactly what the 'derailment detectors' consist of, how they operate, and how they are arranged to gracefully degrade where possible. There are a number of different modes of derailment, each of which may 'deserve' or demand its own specialized response that needs to be implemented no less quickly than in seconds, with little control latency given the comparatively long response of the actual power-braking foundation on current freight cars. But modulation fore and aft of a 'differentially-braked' supposed derailed car, whether or not trainline continuity is lost, is desirable to preserve. (Lest the cure become worse than the disease...)
EuclidBut aside from that ability, it won't actually be needed because there will always be some interval between the sensing of a derailment and the breaking of the wire in which this system can tell the controller where to differentiate the two sections of cars, thus telling the trailing section to go to full default “Emergency” response; and tell the leading cars to go to the specialized reduced force response.
This is an interesting control modality. I am tempted to suggest that you modify it slightly by commanding a full service brake on the rear, which then transitions to 'emergency' as soon as the brake gear has set up completely under control (or automatically, as currently provided, if the trainline continuity becomes lost. That will give you the full time benefit of ECP for commanded reduction without losing at least the ability to modulate both halves of the train under control until everything is predictably set 'equally' for max braking.
At some point there may be a period of time where the front end needs to 'stop' more positively than the max service set, but less heavily than full mechanical emergency. I see a potential problem with excessive draft-gear or coupler force in that instance if you are controlling differential only with the front railed 'end' of the train. (This may not be significant in a given accident's consist, but I worry that in a very wide range of contexts it might be).
tree68 M636C I think that if USA railroad managers had closely inspected the operating ECP trains in Australia last June they would have had to reconsider their position. I would opine that there are only two things that will cause US railroads to adopt ECP: 1. Government Regulation 2. Proving that ECP has an ROI sufficient to make it worth their while (ie, increasing the bottom line). At this point, #1 hasn't come into play for general railroading, and #2 hasn't shown it's face or ECP would be delayed only for lack of parts.
M636C I think that if USA railroad managers had closely inspected the operating ECP trains in Australia last June they would have had to reconsider their position.
Despite the recent statements by our political leaders, Australia is not noted for innovation.
However, in 2005, what is now Aurizon introduced their first unit coal trains in the Hunter Valley and used the first AC traction locomotives and the first trains with ECP brakes.
Clearly, with no significant numbers of locomotives and cars in that area (and in their case, on that track gauge) they were free to start as they wished and they had the first regular ECP trains and the first AC traction locomotives.
In the eleven years since, every operator in that area has wholly or partially converted to ECP, even the operators who had substantial quantities of conventional locomotives and cars.
Also in 2005, Pacific National purchased four GT46CWM locomotives. These were effectively low clearance SD60s and EMD asked a couple of times "are you sure that's what you want?" Since then PN have purchased only AC traction locomotives and all those are fitted for ECP braking.
These are all private companies worried about the bottom line. They don't see their competitors internal costs but they see the published profits. They do see the ECP trains running with fewer brake and wheel defects, able to run faster due to reduced stopping distances for service applications.
When PN decided to enter the Central Queensland traffic to compete with Aurizon there, they purchased only ECP braked equipment and only AC traction locomotives (including AC traction electric locomotives).
Back in the Hunter Valley, there has been a downturn in coal and the ECP trains are running and conventional trains being stored.
A whole order of coal hopper cars from the 1990s suffered from cracking due to the stainless steel being unexpectedly harder than specification. As these are replaced with new car bodies using the old trucks and couplers and brake gear, the new cars get ECP instead of triple valves. It costs a little more but the operators see a tangible return on the investment.
Even visting USA executives should detect the trend.
One thing to remember about US unit coal trains - in many cases the cars are owned by private interests - not the trailroads - they are also maintained by private interests - not the railroads. If the private owners thought there was a ROI sufficient to cover the costs and add to the owners bottom line - they would be shouting and demanding ECP for the operation of their equipment. You don't own and maintain several hundred upto several thousand railcars and not think about the bottom line of your ownership.
BaltACD One thing to remember about US unit coal trains - in many cases the cars are owned by private interests - not the trailroads - they are also maintained by private interests - not the railroads. If the private owners thought there was a ROI sufficient to cover the costs and add to the owners bottom line - they would be shouting and demanding ECP for the operation of their equipment. You don't own and maintain several hundred upto several thousand railcars and not think about the bottom line of your ownership.
I perhaps should explain some aspects of Australian Railways.
The tracks are owned by the state governments. Outside Queensland and Western Australia the main lines are leased to the Federal Government and operated and maintained by an operating authority the Australian Rail Track Corporation which acts as a commercial entity.
As a result, an operator can lose the traffic from a mine on a straight commercial basis, since the tracks accessing any given mine are open to all operators.
One mining company, Whitehaven, purchased their own train (3 x EMD 4300 HP locomotives and 80 coal hoppers) which is operated for them by Pacific National, presumably at a lower rate than PN charge for supplying a train.
Another company, Glencore, purchased nine trains and thirty 4350 HP GE locomotives which carries all their coal and that of some others, and is operated by Freightliner, a subsidiary of Genessee and Wyoming.
Both Glencore and Whiehaven purchased only ECP equipped stock, and Glecore bought theirs in three batches over years, so they must have thought the additional cost was worth the effort.
In Central Queensland, the BHP Billiton Mitsubishi Alliance (BMA) a coal miner, purchased thirteen electric locomotives and nine trains all fitted with ECP braking to be operated by Pacific National.
The operator who had all conventional fleets are converting to ECP (not just testing one train) so they must be convinced of the return on investment too.
While conditions are different in Australia, return is important and cometition is serious. Pacific National lost a mine contract to Glencore/Freightliner (who run only ECP trains) and as a result PN have started to put non ECP cars and locomotives in storage.
The return on investment is there, both to operators and private owners of locomotives and cars or they wouldn't keep buying ECP equipment.
I can't believe that conditions are so different in the USA that the same ECP gear on basically similar rolling stock won't give the same favourable return on investment.
EuclidWizlish, When you speak of modulating the brake application, what characteristics of that modulation are you considering? You cite the modulation in reference to your father’s system for Conrail for the brake response to PTC. I assume that the point of this modulation was to prevent the braking train from derailing. I further assume that this would be controlled by providing strain gages on draft gear to measure the buff and draft and then tell the ECP system what to do in order to balance the buff and draft forces draft in a train in order to prevent a derailment during a hard stop.
It was actually something quite different, and much more 'simple-minded' (as might be expected from '80s technology).
The 'problem' was that the effect of PTC, at that time, was similar to ATC in triggering a full 'penalty brake' application (if not in fact an emergency application) when a signal was passed -- much the same, I think, as the operation of the PZB 'intermittent' train control would have done. There are movies of test trains, I think on New Jersey Transit, that show the result.
The problem is, or was, that the testing was done on passenger consists, whereas the problem, for Conrail after the Chase accident, was that the trains that were needing to be 'stopped quickly' were particularly long and heavy freight trains, of 'interchange' quality as far as maintenance or any sort of special equipment like ride-height braking load adjustment would be concerned, operating at high speed.
That meant that all sorts of 'cure-worse-than-the-disease' knuckle snatching, derailing, and perhaps even stringlining might be observed if the 'wrong' consist were to be automatically big-holed by a nominal "safety" system.
What my father proposed was a safety system that worked in 'parallel' with the service brake valve. but was implemented in a handheld system that would be assigned to a particular engineer (the special part of the system on the locomotive being a proportionally-controlled 'rotair' valve, not a modification to the regular brakes). The idea was that a given consist's information (weight, load, car type, etc.) would be translated from the manifest into a 'computer model' of how the train would be handled in fast braking by a good engineer, and a 'penalty' application from the ATC/PTC system, whether from overspeed or signal violation, would result in the rotair valve 'simulating' how that engineer would work the regular brake handle over time to make a best-distance stop for that particular train.
Of course a much more 'sophisticated' version of this would have additional sensors in the equipment, or modules put in the train every so few cars that could read brakeline pressure, load between the knuckles and coupler faces, etc. But that was not the 'point' of the actual system, which was simply to make the automatic system imitate a human engineer stopping an ordinary train under then-ordinary conditions, instead of just pretending that dumping the air was the answer.
EuclidTherefore, with ECP, a “Service” application can stop the train just as quickly as an “Emergency” application—if the “Service” reservoirs are fully charged. However that might not be the case, so the system includes “Emergency” reservoirs that always hold a full charge in reserve just for an “Emergency” application. Therefore, with ECP, the one main difference between a “Service” application and an “Emergency” application is which of the two reservoirs provides the air.
Point of order: The current system also includes an emergency reservoir. It's not a feature unique to ECP.
tree68 Euclid Therefore, with ECP, a “Service” application can stop the train just as quickly as an “Emergency” application—if the “Service” reservoirs are fully charged. However that might not be the case, so the system includes “Emergency” reservoirs that always hold a full charge in reserve just for an “Emergency” application. Therefore, with ECP, the one main difference between a “Service” application and an “Emergency” application is which of the two reservoirs provides the air. Point of order: The current system also includes an emergency reservoir. It's not a feature unique to ECP.
Euclid Therefore, with ECP, a “Service” application can stop the train just as quickly as an “Emergency” application—if the “Service” reservoirs are fully charged. However that might not be the case, so the system includes “Emergency” reservoirs that always hold a full charge in reserve just for an “Emergency” application. Therefore, with ECP, the one main difference between a “Service” application and an “Emergency” application is which of the two reservoirs provides the air.
Euclid tree68 Euclid Therefore, with ECP, a “Service” application can stop the train just as quickly as an “Emergency” application—if the “Service” reservoirs are fully charged. However that might not be the case, so the system includes “Emergency” reservoirs that always hold a full charge in reserve just for an “Emergency” application. Therefore, with ECP, the one main difference between a “Service” application and an “Emergency” application is which of the two reservoirs provides the air. Point of order: The current system also includes an emergency reservoir. It's not a feature unique to ECP. I said that the difference between ECP and conventional air brakes was how they operated their “Service” and “Emergency” applications. I elaborated that ECP includes a dedicated “Emergency” reservoir only to clarify that point about ECP. I did not say that the “Emergency” reservoir is not included with conventional air brakes. When I said (with ECP) the one main difference between a “Service” application and an “Emergency” application is which of the two reservoirs provides the air; I was referring at that stage to the difference between the two types of brake applications within ECP. The point of that difference between the two brake applications was opposed to the case with conventional air brakes in which there are other differences between the two types of brake applications besides which of the two reservoirs provide the air. The main difference I had in mind is that a “Service” application with conventional air brakes must have a limited rate of reduction in order to avoid triggering a change to an “Emergency” application. I assume that this is not the case with ECP because its electrical control dispenses with the need for the pneumatic control feature of conventional air brakes that produces an “Emergency” application on the basis of the rate of reduction triggering the “quick action” of the triple valves.
There is still the need for pneumatic actuated emergcy applications - when the train becomes uncoupled for whatever the reasons (slip over, unlocked coupler operation, broken knuckle, drawhead failure etc. etc.) as the airline will be opened to atmosphere and the electric line uncoupled.
Unless there are batteries on the cars, charged from the train-line electric cable. Then, loiss of signal applies the brakes from the batteries. Probably just as expensive and requireing greater maintenance than the above, however.
Remember that 'Emergency' is just as pneumatic on a current ECP setup as it is for Westinghouse for any of the events BaltACD mentions. If there are reserve power means on the cars, the emergency will follow quick opening of the valves; if there is no reserve, the valves are arranged to 'fail safe' by going to maximum (design) application as they de-energize.
If you remember M636C's comments about how crosstalk was supposed to be causing 'emergency' events -- if the computer 'thinks' it has lost control authority ... or if it in fact does lose authority and cannot modulate valves ... the default is essentially indistinguishable from a 'big-hole' emergency application. I do not think there is a way to design a truly 'failsafe' EC system (without distributed power and intelligence!)) that would not have such a behavior to some very significant extent.
Part of this of course is that, as I understand it, the current kind of ECP dual-mode conversion leaves the triple valve intact and provides a secondary modulating valve that 'bolts to it'. So any catastrophic drop of the (kept continuous) line pressure in an ECP one-pipe system will, when the pressure drops to where the 'existing' triple actuates, cause things to behave 'just' like a regular Westinghouse-equipped car going to emergency after a trainline break (well, maybe a little slower if the line starts at a higher actual gauge pressure...). In that case there 'might' be a little more or less actuating pressure depending on where the ECP valve was when it 'de-energized' and it was 'designed' just to stop in whatever position it was when the lights went out, or automatically closed to avoid 'false actuation conditions'.
Wizlish Remember that 'Emergency' is just as pneumatic on a current ECP setup as it is for Westinghouse for any of the events BaltACD mentions. If there are reserve power means on the cars, the emergency will follow quick opening of the valves; if there is no reserve, the valves are arranged to 'fail safe' by going to maximum (design) application as they de-energize. If you remember M636C's comments about how crosstalk was supposed to be causing 'emergency' events -- if the computer 'thinks' it has lost control authority ... or if it in fact does lose authority and cannot modulate valves ... the default is essentially indistinguishable from a 'big-hole' emergency application. I do not think there is a way to design a truly 'failsafe' EC system (without distributed power and intelligence!)) that would not have such a behavior to some very significant extent. Part of this of course is that, as I understand it, the current kind of ECP dual-mode conversion leaves the triple valve intact and provides a secondary modulating valve that 'bolts to it'. So any catastrophic drop of the (kept continuous) line pressure in an ECP one-pipe system will, when the pressure drops to where the 'existing' triple actuates, cause things to behave 'just' like a regular Westinghouse-equipped car going to emergency after a trainline break (well, maybe a little slower if the line starts at a higher actual gauge pressure...). In that case there 'might' be a little more or less actuating pressure depending on where the ECP valve was when it 'de-energized' and it was 'designed' just to stop in whatever position it was when the lights went out, or automatically closed to avoid 'false actuation conditions'.
Wizlish If you remember M636C's comments about how crosstalk was supposed to be causing 'emergency' events -- if the computer 'thinks' it has lost control authority ... or if it in fact does lose authority and cannot modulate valves ... the default is essentially indistinguishable from a 'big-hole' emergency application.
If you remember M636C's comments about how crosstalk was supposed to be causing 'emergency' events -- if the computer 'thinks' it has lost control authority ... or if it in fact does lose authority and cannot modulate valves ... the default is essentially indistinguishable from a 'big-hole' emergency application.
My comments about crosstalk were that I didn't believe it has ever occurred in real life. I have seen hundreds of ECP trains pass eachother at full track speed or dead slow and there was never any interaction of any kind.
I have seen an empty 80 car coal train stop following an emergency application and it did so so quickly and quietly that I didn't believe what I was seeing. There was no run in of slack. The train which was doing around 40 mph just stopped in less than its own length. The faulty signal was visible from a bridge I was standing on but not visible to the crew before they cleared the bridge. The train stopped with about 1/3 of the cars still in rear of the bridge.
I don't know the specific arrangement of air reservoirs on those cars, but it worked well.
My short answer is that it makes no difference, as long as both reservoirs are fully charged. Both types of application can happen instantaneously. Both will produce the same braking force. Both can be initiated by the intact wire when the affected derailment detector sends the signal to the ECP controller.
(They appear to be tinkering with the automatic 'quote' function, so I used BBcode directly)
As a 'nit', the ECP "emergency" application with an intact trainline will set up on the part of the train away from any command control valves (engineer's brake valve, properly-equipped FRED or DPU, an 'air repeater' midtrain car or Dave Klepper's midtrain valves, etc.) a little quicker, and that is the source of most of the observed "3%" difference. The 'rest' would come in if the ECP system is 'reliable' enough that a faster application rate in emergency without overshooting pressure on cars that can't handle 'excess' developed pressure can be achieved.
I'm uncertain whether the latter effect is safe to assume if the control cable (or other modality) parts or is impaired; I also presume that an ECP system that sets a 'penalty brake' emergency when it detects something like LOS or a wrong checksum or whatever would default to some 'maximum safe rate' and not to what the system could achieve under full sensing and feedback authority.
If the trainline parts, and the ECP is a 'hybrid' system, I expect the actual setup may be slower for ECP than one-pipe, because the trainline pressure will have to fall further before the physical triple valve ports over and the brake cylinders start to fill. If, as I think highly likely, the control cable 'parts' at roughly the same time the air line does, any 'default' modulation of the individual valves would depend on the way the particular ECP system handles catastrophic power-off (as distinct from catastrophic LOS of analog, digital, or mixed control signals). But this is an extreme case!
In my opinion, 'differential braking' in this situation would control the ECP on the 'front' end SPECIFICALLY to a service brake and not emergency application, not least because that preserves some chance of controlling the front end to keep out of the way of the back end piling up and sliding. if you have a dedicated ECP system (no use of a drop in the 'constant' supply pressure to actuate physical triple valves as a backup) then you have the authority to command graduated release on part or all of the 'intact' forward part of the consist, and even apply power to accelerate the train 'away' at graduated release ... but I'd think this will be much easier with a 'service' application than the digital equivalent of big-holing.
Most (perhaps all) the part of any system that controls braking with a 'derailment detector' is going to be concerned with trains that have not broken in two; in fact one of the important parts of having derailment detection at all is to prevent actual breaks from happening. So I think it makes some sense to have the 'right kind' of derailment detector ... one that can discriminate between different things happening with the truck position or perhaps geometry, and that understands when flange force or wheel accelerations are wrong, and that can communicate with the brake controller to 'figure things out' as much as possible, and as long a lead time as possible, before catastrophe actually starts. And then develop some protocol, probably involving metadata codes, that signal 'events' of progressive importance (as if they were guide numbers) to the ECP controller, so that the choice of differential vs. progressively 'fuller' service braking vs. emergency can be made with better assurance.
As I understand it, both 'commercialized' and marketed systems of American ECP (WABTEC and NYAB) use a procedure to establish physical location of the different cars at 'startup' (and, presumably, in realtime any time a car is switched out of a consist, etc.) It is comparatively simple to establish a metadata 'protocol' that tags a derailment-detector code with data associating it with a specific car, and in turn with that car's position, derived weight or maintenance state, etc. So nothing radical should be required either in the equipment or the programming to add the important part of this functionality ... in my current opinion.
(I should insert here that I still think redundant wireless backup, and some self-power and modulation for the ECP valves, is a valuable thing in one of these systems, but of course YMMV.)
I confess I have never quite understood what the controversy with 'crosstalk' between trains using twisted-pair conductors was supposed to be. My father thought that some 'early' applications might not have twisted the conductors "enough" (perhaps not at all?), thinking they were power and not mixed power/data. Certainly none of the Australian adopters would be that dumb.
Euclid However, if the electric train line parts after the two applications are triggered, the application behind the derailment cannot be further modified. Off hand, I cannot see any reason why the trailing application should ever be less than maximum force; or would need any further modification during the stopping process.
You're with buslist and some other very smart people in thinking this. I still think that it would be better to modulate the application, even if the 'ultimate result' is to have the brakes applied with full 'emergency' force and perhaps sliding, and I also think that this needs to be done with some sort of wireless enablement.
My current thought is to put simple metadata into the DPU protocol that could be 'read' by the (still connected) processors in a following segment. Presumably it is not a 'difficult' exercise to provide tail-end 220V emergency power from a device on the 'disconnected' part of a consist, whether or not actual DPU power is there, so the issue becomes how the rear brakes are modulated IN SPECIFIC EMERGENCY CONDITIONS -- this would probably involve a special reception mode and perhaps an 'emergency button' (tied in with PTC somewhere) that would actuate the DPU overlay recognition or priority if automatic systems did not do the job right.
This might only be good for 'a couple' of stops to rest, but it would assure as well as much more complicated systems that the rear end of the train progresses to maximum achievable safe deceleration and then a stop in minimum-time or minimum-distance in the 'best' way that jurisprudence, insurers, lawyers and newsworkers would recognize...
This would also coordinate overall as well as incremental braking rate relative to some 'conditions' ... most notably, if the rear of the train turns out to be stopping "less slowly" than expected, or if it were to start to move again after stopping for some reason, there could be an indication (both automatically and to the crew) that they should do a graduated release even before (as would apply in any other circumstance I could conceive) the front-end crew has not yet been able either to walk the consist or assess the 'state' of the cars at the point of separation.
I'm taking up the point in your last paragraph in a following post.
EuclidOne factor in particular to consider for reason to modify the brake force on the leading cars is the train speed. If the train deceleration happens to be exceeding the initial expectation of the system, then the application on the leading cars might be increased; and vice versa.
I would be a little more careful about 'which cars' get the increased braking effort, both in terms of reduction of train speed in different ranges (especially high speed, where you will want to modulate 'loads' differently from empties even if you haven't telemetered the load sensing, e.g. with higher effort on the loads initially shifting to a 'bias' toward the rear end of the consist to keep the slack from run-in or oscillation as the speed comes down.
The situation with unexpected deceleration also has a couple of aspects. This does not only involve graduated reduction of the front end to 'keep out of the way', it might also call for quick reduction if derailed cars start acting as an anchor and you want to preserve your drawbar integrity through the 'forward section' to avoid more potential run-ins.
I have already addressed some of the 'reasoning' for why you would want brake modulation relative to deceleration on the rear part of the consist, and at least one way that could be achieved without compromising more than about 3% of the ultimate "ideal-case" stop time or distance.
Wizlish Wizlish It's a bit like emergency brakes that make trains 'stop short' at crossings. There is technology that could do this, and we've discussed it in a couple of fairly long threads. I don't recall anything like that ever being discussed here. How would this be accomplished? Under what terms would "stopping short" occur? Dave Klepper, I think, started a thread on electromagnetic track brakes, in which I think you participated. Interestingly enough, erikem did an engineer's analysis on the requirements to actually make such a thing work at full scale and concluded it could be made to function. The basic idea (correct me anyone if this is wrong) is to provide an electromagnet of appropriate field strength and characteristics that 'rides' along the railhead, with enough cross-sectional area to produce both 'clamping' friction and eddy current induction in the rail steel. When a high current is applied through this magnet it produces a strong retarding force, independent of any braking being applied to the wheels, and under some circumstances it can exert a restoring force to keep a carbody (or truck frame, perhaps) in line with the rails. There is a limit as to energy dissipation (in part set, I think, by the Curie point of the railhead) and there are some potential problems with rail lifting or activation on curves or crossovers, and of course with dramatic problems in train handling if there is any differential slack or disproportionate braking level in different parts of the train. A version of this is and was applied historically to streetcars, where it has I believe been demonstrated to work quite well, at the (unexpected to me) cost of increasing rail corrugation when used more than intermittently. Apparently modern Li-ion battery tech has gotten to the point that it can store enough energy to brake a given loaded car down to a reasonable speed in a respectably short time ... once. It may not matter if parts of the system, or indeed parts of the track, require even expensive repairs when the emergency track brake is 'fired'. The more important consideration -- which as I mentioned would be difficult if not impossible to substantiate -- is whether the system introduces more danger or risk than it relieves.
Wizlish It's a bit like emergency brakes that make trains 'stop short' at crossings. There is technology that could do this, and we've discussed it in a couple of fairly long threads. I don't recall anything like that ever being discussed here. How would this be accomplished? Under what terms would "stopping short" occur?
I've just read the whole thread, and I just can't keep from commenting on Wizlish's post, where he has described the system quite well. Probably this has already been said somewhere else, but here is the state of things in Germany.
Trams have been legally required since 1950 to use track brakes to achieve the mandated deceleration (about 9 feet per second squared). On heavy rail, every vehicle except locomotives which is certificated for speeds above 140 km/h (87 mph) has to have such a brake; brakes on individual vehicles are powered by batteries. This applies, of course, mainly to passenger equipment, as very few freight vehicles operate at speeds above 120 km/h or 75 mph.
(I hope the picture landed in the post, have no experience doing this).
This kind of brake is, AFAIK, used in this fashion everywhere in the UIC region (Europe without former USSR). DB ICE3 EMUs have a contactless brake system using only eddy currents for braking.
Electrically-signalled pneumatic brakes are in widespread use on passenger equipment; they can be controlled either by electric signals transmitted by cable or in the traditional way by pressure in the air line. In the UIC version of this system, the locomotive provides electrical power to the train via the UIC-standard cable link and is therefore suitable for freight equipment. the cable link is constantly monitored for malfunctions or train separation. The UIC region once planned to convert all rail vehicles to automatic couplers (the AK69E); tests had shown that conventional pneumatic brakes in conjunction with these couplers led to inacceptable slack action up to derailments, so it was planned to use EP brakes throughout. The conversion to automatic couplers was planned to happen on an Easter weekend (I think in 1972) all over Europe at the same time, but a number of countries balked - understandably. As the new coupler was completely incompatible with the traditional screw-link coupling every vehicle would have to have been converted at the same time, and the total number of vehicles concerned was certainly at least comparable to the number of rolling stock in the US, with a considerably larger number of locomotives. I seriously doubt the changeover would have been possible in much less than a month, with a resulting disruption in rail traffic. So the automatic coupler didn't happen, except in special applications (mainly ore unit trains above 4000 tonnes) and EP brakes in freight applications died with it.
Our community is FREE to join. To participate you must either login or register for an account.