A few years ago there was considerable discussion on electric brake control on long consists - especially unit trains. As I remember, they controlled the air application [the air was still the force behind the breaking] with a 220v line that ran the length of the train. Brakes could be set and released at the same time without having to wait for the air pipe reductions to “wave” through the train. I have not seen anything about this is a while, does anyone know the state of use/development?
Chicago uses this on its transit vehicles.
It has been looked at for unit trains, yes, but you would need to install a trainline wire. Easy enough to do on new equipment, dedicated to run with like-kind equipment, but in regular freight service, not very likely (in my opinion).
I think with the development of distributed power, the issue has become moot.
But what do I know. I do not work for a railroad, but I did stay at a Holiday Inn last night.
ROAR
I think you’re talking about Electrically Controlled Pneumatic brakes, or ECP. These used electrical signals to cause a brake application rather than the change in brake pipe pressure. Obviously, they could only be used on uninterrupted blocks of cars coupled to the locomotives, so Norfolk Southern, BNSF, and Canadian Pacific were experimenting with their use on unit coal trains.
The advantage was that the brakes could be applied faster than what’s currently used - a brake pipe pressure reduction used to trigger the triple valves on each car - therefore decreasing stopping time. However, brake releases still rely on the air pumped through the brake pipe to release the brakes on every car. There’s no change there.
I believe ECP is still undergoing real world, day in, day out testing.
The biggest failing that I can see is the reliability of the electrical components in a near ‘maintenance free’ environment that the carriers would demand for universal acceptance. Anything that would require additional manpower to maintain and service on a shorter service cycle than the present day equipment experience would be a ‘deal breaker’. The other issue would be retro-fitting the existing car population as to achieve the full benefit of ECP it needs to be effective on all trains.
I believe some unit ore trains experimented with trainlined solinoid valves replacing the Retainer valves. This made it possible to maintain brake cylinder pressure while recharging the equipment via the brake pipe. I believe the Orinoco Mine trains used this but I don’t for how long. It was a tricky manipulation that could get you in trouble if mis-used. As memory serves me, WABCO tested it on their 150 car freight train rack and trrained the enginemen on its use
Link to the FRA’s webpage on Electronically Controlled Pneumatic (ECP) brakes: http://www.fra.dot.gov/rrs/pages/fp_1713.shtml
The August 2006 “ECP PowerPoint Presentation” (25 slides, approx. 632 KB file size) and the August 2006 Booz Allen Hamilton Report (78 pages, approx. 1.08 MB file size) are both very interesting. Notably different from some of the comments above, the ECP brakes are also released electronically - there is only 1 air line, so the control signals and functions are all transmitted by electronics, not by air pressure variations - so there can be a ‘graduated release’ instead of the present ‘complete release’ mode.
See also this thread here - “ECP-What good is it?” from Feb. 2009 through March 2010 at: http://cs.trains.com/TRCCS/forums/t/147823.aspx?PageIndex=1 The Original Poster who started that thread - kolechovski - apparently has observed or heard about quite a bit of trouble with the ECP brakes on NS unit coal trains to a powerplant near him.
The “Orinoco” or “Orinocco” air brakes use a complete 2nd air line to only recharge the brake cylinders; the main brake line transmits the air pressure variations for control signals and functions to the triple valve. See this other thread here from January 2011 - “Straight air brakes” at: http://cs.trains.com/TRCCS/forums/p/186414/2037681.aspx#2037681
- Paul North.
One more line that the ground guys have to hook up. The biggest thing is the outside exposure on a rail car, specificly coal hoppers, have to be hell on any electoric componets. Electrical compents also tend not hold up as long a things like steel and rubber. I guess with time will see if the benifits will outweight the cost of going to such a system.
iS NOT NS RUNNIG ONE UNIT TRAIN CURRENTLY WITH ELECTRICALLY CONTROLLED BRAKES?
ALL MU OPERATED PASSENGER TRAINS ARE EFFECTIVELY ELECTRICALLY CONTROLLED IN BRAKING
INCLUDING ACELA.
In Australia, all major operators have been adopting ECP brakes for unit trains since 2005 when QR National started running export coal trains in the Hunter Valley. They now have twelve trains with ECP brakes running daily, each with 72 wagons carrying a bit over 100 tons each. Pacific National have six ECP trains and thirty conventional trains of the same size and Xstrata Coal have six such ECP trains with three more coming. In the Pilbara area of Western Australia, Fortescue metals have only run ECP trains since their inception in 2007 and Rio Tinto have started conversion to ECP.
One thing really noticeable with ECP trains is the reduction in wheel skids since all brakes release simultaneously and trailing vehicles are not dragged against sticking brakes.
The trains can run faster since the crews can be confident of rapid and effective braking.
I was standing on road bridge at Tarro in the Hunter Valley and photographed a QR National train approaching the bridge. The next thing I saw the train had stopped, and looking at a signal on that track about a mile from the bridge I saw that it was cycling through green, amber and red at about one second intervals. Approaching the bridge, the train appeared to be doing 50 mph, the line speed for unit trains and it had stopped in less than half a mile with no noise or run in of slack.
M636C
Passenger equipment receives a quantum amount more maintenance than does freight equipment - as well as passenger equipment never has to go through a thawing shed to thaw out it’s contents before unloading or receive steel ingots that are still in the ‘red’ stage of their cooling cycle. etc. etc. etc.
I do not expect universal conversion to ECP brakes unless they are mandated. There was a universal conversion to automatic couplers from link and pin couplers, and a universal conversion to air brakes from hand brakes. But for ECP brakes, I believe the horse has left the barn. The cost of present ECP technology for universal conversion would be astronomical. And I do not believe the current electrical hardware is anywhere near durable enough to withstand routine operation. So, there is more cost yet to come.
The benefits of ECP, such as graduated release, are irresistable, but engineers have been running trains without graduated release for a long time.
NS is running 6 trains and all new power is coming equipped to control them.
Economics is everything.
I would submit that we’ll see continued expansion in dedicated car fleets (ie, unit trains) while “loose car” applications will take a long time.
Perhaps the next step (once most of the near-permanently coupled unit trains are all set up) will be regularly assembled trains such as the UP “salad shooter” or the Tropicana juice train.
Yes - Economics is everything.
The ‘dedicated car fleets’ are privately owned to service the owners need - what is the economic return to the owner for the additional investment in ECP equipment on the cars in their service? These dedicated car fleets can run over 1000 cars for each owner at present. Do you equip these fleets retroactively since they still 20 to 30 year or more economic life span? Do you scrap you present fleet to obtain a new fleet that is designed for ECP braking.
I might add that trains such as the Tropicana Juice train is not as ‘permanently coupled’ as one may think. The loaded train originates out of Bradenton, FL and operates to Jacksonville where it gets split three ways. Part of the train heads West to a California terminal that Tropicana has recently built, another part goes Northwest to a Tropicana terminal near Cincinnati. The largest portion of the train goes up the East Coast to the Tropicana terminal near New York City, The portions that head West and Northwest are handled in regular merchandise freight trains. The portion to NYC is handled as as solid Tropicana train (note - Tropicana owns
Saudi Arabia Railway is using ECP on three unit trains hauling phosphate.for about a year.
sparky61 - Welcome to trains.com! [C):-)]
I thought I’ve seen some newer cars, mostly coal hoppers (including technically those that are gondolas) and covered hoppers that have some of the ECP components on them. They aren’t ECP capable, but have some of the gear for when time comes to conversion.
Jeff