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.
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...
M636C
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
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.
schlimm The Southern Region of BR introduced the electro-pneumatic system for suburban passenger service in Britain in 1950. Still electric, not electronic.
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.
- Erik
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.
Greetings from Alberta
-an Articulate Malcontent
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.
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...
"+1" on the rambling, too. Oh wait, excuse me, now it's called: "data transfer" !
- Paul North.
tree68 I'm pretty sure they had boxcars so equipped in the past.
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.
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
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
Thanks, SD70M-2Dude, and ramble on; I welcome the information. I hadn't given much thought to cold weather problems.
_____________
"A stranger's just a friend you ain't met yet." --- Dave Gardner
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.
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.
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.
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.
If they could modify the EOT to assist in a service application that would be helpful.
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.
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.
Never too old to have a happy childhood!
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.
Norm
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.
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.
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...
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.
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.
Jeff
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 knew that. I think the UP's M-10000 or maybe Pioneer Zephyr? But widely used in GB.
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.
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.
C&NW, CA&E, MILW, CGW and IC fan
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
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.
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.
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...
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