I wonder what the status is of this? Trains did articles a ways back and it seemed some railroads were experimenting with electronic brakes on long coal trains. Have not heard much of late on the subject. Are railroads going to eventually replace compressed air with electronics or will it take another act of Congress to step in at some point and force the issue?
To me I think the benefits of electronic braking outweigh the negatives. Especially given that trains are getting longer in length and we probably will see an increase in the mixing of passenger trains with freight trains as time goes on. Just seems foolish and a little outdated to stick with compressed air for braking.
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
Our community is FREE to join. To participate you must either login or register for an account.