jeffhergert caldreamer How would ECP or multiple end of train devices help prevent stringlining which is a major problem on mountian grades? End of train devices do not make service brake applications. The only brake command they are currently capable of is to dump the air when initiated by the engineer. The idea behind the original post about using multiple ETD for what I perceive as normal braking operation isn't possible with the current equipment. You would need to redesign the ETDs to do that. Multiple DPUs within a train is already possible and would give the same benefit as "multiple ETD/MTDs" throughout the train. The only drawback with DPs through out a Hazmat train is the need for buffer cars on each side of each mid-train DP. Jeff
caldreamer How would ECP or multiple end of train devices help prevent stringlining which is a major problem on mountian grades?
How would ECP or multiple end of train devices help prevent stringlining which is a major problem on mountian grades?
End of train devices do not make service brake applications. The only brake command they are currently capable of is to dump the air when initiated by the engineer.
The idea behind the original post about using multiple ETD for what I perceive as normal braking operation isn't possible with the current equipment. You would need to redesign the ETDs to do that.
Multiple DPUs within a train is already possible and would give the same benefit as "multiple ETD/MTDs" throughout the train. The only drawback with DPs through out a Hazmat train is the need for buffer cars on each side of each mid-train DP.
Jeff
Some form of ECP and/or PTC is used on many railroads in the world.
C&NW, CA&E, MILW, CGW and IC fan
It seems to me the railroads that have converted to ECP are mostly those that operate bulk commodity/unit train operations, if not outright captive equipment. The business argument for them is probably easier to make.
It reminds me of those times when someone brings up some new idea, like the cargo-sprinters, etc. Many of them would be possible, IF you were starting from scratch or had an entirely captive system, like in some countries where the rail system hasn't been developed to a large extent. It's when trying to impose something "new" on an existing system that things won't always easily mesh. Those supporting the idea/equipment think the only reason it's not adopted is because those in the industry are "dinosaur/stuck in the mud/luddites" who just can't see the light.
It also seems the most vocal boosters are those who either have skin in the game (vendors) or not much real world experience in how things work.
M636CIn the USA, there appears to be a search for reasons why ECP won't work, rather than just adopting it. The Australian companies adopted ECP because they think it saves money, and nobody is changing back...
Given that and Euclid's post on a Canadian railroad's favorable (saves money immediately) experience with ECP, resistance here seems to be coming from a short-sighted, uninformed bean-counter perspective and "the search for reasons why ECP won't work" is more of a search for excuses to not adopt (along with objection to any government mandates). The history of adoption of safety improvements by US rails shows resistance to voluntary adoption going back to the Janney coupler.
It's my understanding that dual mode ECP equipment only works in one mode at a time. A train is either in one mode or the other. If the car is in an ECP unit train, it's operated in ECP mode. If the car is in a general freight (with other equipment not equipped for ECP) it's operated in conventional mode. There is no provision to operate "half and half" so to speak.
I'm not against ECP. I think it would make my job a bit easier, provided it could be used properly. I'm just able to see the railroad's current point of view. I'm sure if the railroads could completely eliminate all "loose car/car load" operations and go to strictly unit style trains, they would be more willing to embrace ECP.
I don't have any specific information on how dual mode freight cars are set up.
It would appear to be easy to incorporate a slide to cut off the conventional valve from the "adapter" version of the ECP valve. I think the SSR coal hoppers that appear to work in both modes have this type of ECP valve, but I don't know how the changeover occurs.
In the case of locomotives of course, all ECP locomotives can operate conventional trains without modification, so there is no problem.
A "through cabled" non ECP locomotive can run in an MU consist hauling an ECP train because the locomotives still operate with conventional independent air brakes.
When talking about "through cabled" freight cars, I was assuming that these would run as unbraked vehicles in ECP trains, just as "through piped" unbraked vehicles ran in British vacuum braked trains in the 1930s to 1960s. There was a limit to the number of unbraked cars that could be run if the train was to be treated as a braked rather than unbraked train.
There appears to be no problem with cars from ECP unit trains running in conventional trains because that just doesn't arise. ECP cars have an emulation mode using battery power for short transfer runs, but most operators just move such vehicles with ECP equipped units from yards to maintenance shops.
I'm not trying to promote the use of ECP brakes.
I'm just trying to understand why a system that has been accepted and used in one country is being resisted in another.
I do know a lot about the forces involved in train action, since I spent some years measuring them for Hamersley Iron in Western Australia. My experience suggests that rapid simultaneous brake application could solve a lot of problems. Not all of them, but a lot.
One of the trains I was testing made an emergency stop when the yard controller reversed a signal to red without realising how close we were. The 220 car train broke in five places, one break being a drawbar that pulled out of a married pair of cars when the yoke broke, the remainder being at couplers where knuckles broke.
If that train had used ECP brakes, it would probably have stopped with no damage.
I have earlier in this thread mentioned three devastating derailments caused by loss of Locotrol signal at critical points on the Goonyella system. I'm sure Pacific National are pleased that their trains run MU though the ECP cable every time thay pass that section of line with four locos, two at the one and two thirds points and one each end.
There was a derailment that I believe was due to misuse of the ECP brake system. An ECP train was leaving a mine and what I think happened is as follows: expecting the signal to clear, the driver decided to release the train brake and hold the train on a slight downgrade on the independent on the three locomotives. I assume the crew had done this before with conventional trains. However, the quick release of the ECP system compared to the gradual release of a conventional brake immediately threw the whole train weight on the locomotives and all three units were pushed through the catchpoints. This never happened again...
As I've said earlier, there don't appear to be any real disadvantages to ECP operation and unit trains are gradually being converted to ECP. I expect that intermodal trains will be next, because although these aren't heavy, they are long and this affects the operation of conventional Westinghouse brakes.
In the USA, there appears to be a search for reasons why ECP won't work, rather than just adopting it. The Australian companies adopted ECP because they think it saves money, and nobody is changing back...
M636C
M636CExcept for Fortescue Metals, every other operator with ECP braking has a mixed fleet of ECP and non-ECP cars and they cope with it. In Queensland, Pacific National use the same type of locomotive on conventional brake intermodal trains and ECP brake coal trains. The older intermodal locomotives can't be used on coal trains, but the coal locomotives can and do haul intermodal trains with conventional brakes.
Can you give specific detail on the equipment and procedures that are used to provide this 'dual-mode' braking capability?
A conversion of all the freight cars in the USA to ECP would be expensive and may never happen. But the conversion of unit trains carrying oil or coal or iron ore is practical and not that expensive. A staged conversion, as presumably occurred with the change to Westinghouse brakes or the change from link and pin to Janney knuckle couplers is what will have to happen. Some locomotives and some freight cars might be fitted with a through cable to allow the ECP signal to pass through a non ECP vehicle.
As I understand it, a passthrough cable won't make non-ECP cars capable of service-brake compatibility with ECP-converted cars when running under ECP. The one-pipe conversion changes the single brake line to run at main-reservoir pressure all the time, and this precludes any conventional control of the triple valve via pressure differential (although the emergency can still be modulated via air signal in the now-high-pressure air in this hose.)
Where does it help to have wireline continuity (with 230V and required connector signal integrity) throughout the train vs. expanding the existing radio channels now used for DPU? Sure, there are advantages for things like LOS in cuts or tunnels, but those are much more readily addressed with the equivalent of femtocells in phone coverage, aren't they?
I think one Australian operator has vehicles that can be manually changed from ECP to Westinghouse and back. This will cost more but provides ultimate flexibility.
It was my understanding from looking at the WABTEC presentation that the 'adapter' version of the ECP valve was installed directly in line with existing brake equipment (I can find the exact 'slide' number that shows this). It stands to reason that such a car would continue to work with 'conventional' effectiveness with the ECP unpowered/unsignalled (I would expect the ECP valve to default to 'passthrough') but it would appear to follow, again, that the conventional brake gear would actuate in an undesired fashion during ECP operation if the trainline pressure were allowed to fluctuate. This would self-correct when the trainline came back up to pressure, of course, but for some period of time you would have an unpredictable number of cars, in unpredictable positions, with lagging and not graduated release ... without, as far as I know, any indication on the ECP network as to which of them were doing so.
If the point about rapid re-acceleration after brake release is as significant as you indicate -- and I think that it is -- I see a number of alarming implications that have not, so far, been addressed by the ECP promoters in the United States so far.
Euclid The 2006 FRA report on ECP brakes says that ECP can totally eliminate the need for power braking due to the benefit of graduated release. It seems to me that ECP has many advantages over current practice, but the railroads do not believe the benefits are worth the enormous cost of a universal conversion.
Extended range dynamic braking on today's locomotives has virtually ended the need for air brakes, except for the final stop. Dynamic Braking power can be increased and decreased as necessary by the engineer - dynamic braking does not put thremal stress on any wheels - engine or cars. Air brakes put thermal stresses on the wheels of the cars (engine brakes are normally bailed off). ECP increases wheel stress if it were to be used in place of Dynamics.
Well, I guess if the FRA says it's so, it must be true. We all know the government never lets those who have no real world experience make recommendations, rules or regulations.
Never too old to have a happy childhood!
dehusman M636C Surely stopping in a significantly shorter distance in normal service is at least as important as the performance in the less likely emergency situation. Why? During "normal" stops and reductions in speed,the majority of the braking will be done with dynamic braking.
M636C Surely stopping in a significantly shorter distance in normal service is at least as important as the performance in the less likely emergency situation.
Why? During "normal" stops and reductions in speed,the majority of the braking will be done with dynamic braking.
I often can go an entire trip without touching the air until the final stop. With a loaded coal train I may need to use air only in one spot to control speed. All the rest is throttle modulation and dynamics.
It's all about saving fuel. They don't like power braking although grudgingly realize there are times it needs to be done. I think to get the most benefits out of ECP, like graduated release, you will need to power brake more often. With the modern dynamics we have now and distributed power, I think the case for ECP isn't as good as it once was.
"ECP has been TESTED in controlled enviornments - as such it it wholely untested in the real world of loose car railroading - every car, even those in dedicated unit train service get incorporated into the loose car world from time to time and end up away from their dedicated service center. To date, my understanding is, there are competing forms of ECP that are not compatible with each other.
The braking that is being taught to Engineers at present is Dynamic Braking, with air brakes almost becoming the brake of last resort."
It is way beyond testing.
Fortescue Metals in Western Australia ship 155 million tonnes per annum (170 miliion US tons) entirely in ECP braked trains. I honestly don't know how many ore cars they have, but Roy Hill who are setting up a parallel railroad to ship 55 million tonnes per annum have 1400 cars (all ECP), so 5000 cars on Fortescue is a likely number...
A couple of hundred miles away Rio Tinto are converting their fleet to ECP brakes and driverless operation. ECP brakes is a requirement for the operation, which is really remote rather than driverless, like drone aircraft.
Rio used to run 220 car trains with conventional Westinghouse, with 125 tons in each car. They had to put new cars on each end of the train to avoid problems with brakes not releasing.
Back in the East Coast, Newcastle, New South Wales is the largest coal export port IN THE WORLD. Maybe one third (or more) of the trains are now ECP braked, with two main operators Aurizon and Freightliner (now part of G&W) running only ECP braked trains. The other main operator, Pacific National, has only purchased ECP cars for some years. In the last three months they purchased 400 hopper cars of 120 tonnes (132 tons) all up mass and three locomotives (4300HP EMDs) all fitted for ECP and 15 existing GE 4400HP units with EPIC brake controllwers are being upgraded to ECP.
In Queensland, Pacific National only run ECP coal trains (with 52 diesel and 42 electric locomotives) and BMA (BHP Billiton Mitsubishi Alliance) have 13 electric locomotives. Trains run with three or four units in distributed power using the ECP line for control with 200 cars of 105 tonnes (115 tons).
Aurizon are converting to ECP. They have had at least three serious derailments where the Locotrol radio signal was lost in rough mountainous country and mid train units pushed the front section of the train off the track. This doesn't have to happen often for ECP to be cost effective. At least four electric units were lost in these derailments.
And the ECP operation is all done with Wabtec and NYAB equipment and standard AAR connectors.
It isn't testing. It is full time heavy haul railroading with ECP as a basic part.
If it doesn't work in the USA, the USA railroads must be doing something wrong...
dehusman Many people seem to think that "unit train" means it is exactly the same set of cars always traveling together trip after trip. That's just not what's really happening. ...
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This would be a real problem for multiple "EOT"s. Each EOT has to be dialed into the control unit in the engine. If you start to add and switch units between trains, it will be hard to keep them all dialed in correctly.
BaltACD To date, my understanding is, there are competing forms of ECP that are not compatible with each other.
To date, my understanding is, there are competing forms of ECP that are not compatible with each other.
I believe everything in use in NA meets the AAR wire line ECP interoperability spec. The only competing system was the GE Harris wireless system that they gave up on more than a decade ago.
dehusmanMany people seem to think that "unit train" means it is exactly the same set of cars always traveling together trip after trip. That's just not what's really happening.
Also known as "single-bulk commodity trains". Although "unit trains" is just easier to say.
The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.
BaltACDECP has been TESTED in controlled enviornments - as such it it wholely untested in the real world of loose car railroading - every car, even those in dedicated unit train service get incorporated into the loose car world from time to time and end up away from their dedicated service center.
Many people seem to think that "unit train" means it is exactly the same set of cars always traveling together trip after trip. That's just not what's really happening.
Just for giggles, a couple months ago in another discussion I picked an oil car and then looked at the last 20 or so trains it was on. No more than 2 or maybe 3 trains in row had the same number of cars on them. That means that cars were being added and subtracted, the consist was changing, that the exact same set of cars were NOT traveling together. The changes ranged from a couple cars to 10 or more cars total car count between successive trains.
That is similar to the experience with grain trains and coal trains, they are frequently having cars cut out, cars added, the train size going up and down, if by only a few cars every couple of trips. The drawbars are not welded together, the EXACT same consist doesn't ping pong for months at a time.
An added cost, typically not taken into consideration, is managing a small, restricted fleet that can't be part of the "loose car" network (and the associated smaller, restricted feet of engines to haul those cars).
Dave H. Painted side goes up. My website : wnbranch.com
M636C tree68 Euclid Be sure to go on to Slide #8, which shows that ECP offers only a slight improvement over straight air with an emergency application. But the full service application distance is only marginally more than the emergency stop distance with ECP, from slide 7. Surely stopping in a significantly shorter distance in normal service is at least as important as the performance in the less likely emergency situation. The stopping distance for a full service application with ECP is effectively half that of a train with ABD valves and no EOT valves, and better than any of the non ECP options. ECP works, it is proven in applications identical to normal USA operation and it is made by local USA suppliers. It was invented here (if here is the USA). It is not an untried system being forced on the railroads. It is a proven system that works well, particularly with unit trains (like oil trains). No alternative is needed. M636C
tree68 Euclid Be sure to go on to Slide #8, which shows that ECP offers only a slight improvement over straight air with an emergency application.
Euclid
Be sure to go on to Slide #8, which shows that ECP offers only a slight improvement over straight air with an emergency application.
But the full service application distance is only marginally more than the emergency stop distance with ECP, from slide 7. Surely stopping in a significantly shorter distance in normal service is at least as important as the performance in the less likely emergency situation.
The stopping distance for a full service application with ECP is effectively half that of a train with ABD valves and no EOT valves, and better than any of the non ECP options.
ECP works, it is proven in applications identical to normal USA operation and it is made by local USA suppliers. It was invented here (if here is the USA).
It is not an untried system being forced on the railroads. It is a proven system that works well, particularly with unit trains (like oil trains).
No alternative is needed.
ECP has been TESTED in controlled enviornments - as such it it wholely untested in the real world of loose car railroading - every car, even those in dedicated unit train service get incorporated into the loose car world from time to time and end up away from their dedicated service center. To date, my understanding is, there are competing forms of ECP that are not compatible with each other.
The braking that is being taught to Engineers at present is Dynamic Braking, with air brakes almost becoming the brake of last resort.
M636CSurely stopping in a significantly shorter distance in normal service is at least as important as the performance in the less likely emergency situation.
tree68 Euclid This is shown with the stopping distances in slide #7 of this slideshow: Be sure to go on to Slide #8, which shows that ECP offers only a slight improvement over straight air with an emergency application.
Euclid This is shown with the stopping distances in slide #7 of this slideshow:
BigJimI fail to see the purpose or even why you would want two EOT's.
The devices Mr. Klepper is describing aren't EOTDs (except insofar as parts of existing EOTD systems could be used OTS or with minor and cost-effective modification to produce them). They represent only a limited part of the EOTD functionality, the ability to provide an air-brake control valve at some point in the trainline. In the simplest version of the system, all these valves would be slaved to the brake valve in the cab, giving the advantage of 'lightspeed' actuation at distributed points in the train. The abbreviation MTD is a good one.
I think Mr. Klepper is planning to have these valves be individually addressable and to have the capability of at least a limited amount of differing modulation (I have to be careful not to say 'differential' as that has a different technical sense in the present discussion!) There are a number of ways that multiple MTDs could be 'connected', and how the system could determine the relative number and position of devices in a consist. The head-end device (as reprogrammed cf. Caldreamer) would then be able to address each of the devices appropriately, for example to modulate the rate or amount of application at each point, or to close one or more valves while permitting further exhaust by others.
Note that even a slow and 'quantized' version of graduated release would be difficult to implement on this kind of system -- unless I'm nisunderstanding how the valves work. So it's strictly applicable to the scenario of better-controlled rapid or emergency braking down to a full stop. The thing I have to wonder is this: that scenario is almost 100% of what the Feds are calling for from a 'safer' HHFT brake system. (We all know graduated release, differential braking, etc. can improve train handling in some respects, but we've also begun to disagree pronouncedly on whether that improved train handling provides cost-effective improvement in the kinds of 'safety' that politicians care about... or that AAR member railroads care to pay for...)
And we can't forget that while the sole purpose of the brake line under ECP becomes keeping the reserviors charged, there is still a finite amount of air that can be supplied, so it is still possible to "p!ss away" one's air... Might have to work harder at it, but it's still possible.
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...
EuclidWabtec has a chart that gives the emergency application stopping distance of several test trains, including one with ECP brakes. They identify those test trains by the following designations: ABDX ABDW ABD ABDX+1 EOT-ES ABDW+1 EOT-ES ABD+1 EOT-ES DIST. POWER +1 REMOTE ABDX+2 EOT-ES ABDW+2 EOT-ES ABD+2 EOT-ES ABDX+3 EOT-ES ABDW+3 EOT-ES ABD+3 EOT-ES ECP You can see that the last one is a train with ECP braking. I am not sure what the first three designations mean.
Read the description in this patent application and you will be educated:
http://www.google.com/patents/WO2013181189A1?cl=en
Shame on you, Dave, for not just telling him the distinctions.
EuclidThis is shown with the stopping distances in slide #7 of this slideshow:
The 3 variations of modern conventional air brake valves. What in Euclidspeak = "Westinghouse".
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