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.
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.
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.
"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
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.
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.
I don’t know what to conclude about the FRA statement. If power braking can be eliminated by replacing conventional air braking with dynamic braking, the point by the FRA may be moot. I have concluded that the FRA has been waiting for the right moment to mandate ECP just like the PTC mandate needed the right moment. I got a very interesting response from the FRA to a question that I asked them about 12 days ago. They cite rationale for the ECP mandate that goes beyond just oil train safety. That suggests to me that their oil train ECP mandate may just be the first increment of a universal ECP mandate. I will post about it on the oil train thread shortly.
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.
ECP braking is not regarded as an alternative to Dynamic Braking. All the ECP trains I have seen have locomotives with dynamic braking capability and, as far as I know dynamic braking is used as much, possibly a little more than it is on trains with conventional Westinghouse brakes. Because the application of ECP brakes is faster, it is likely that an operator could remain in dynamic braking longer before applying air brakes, thus reducing thermal s
Can you give specific detail on the equipment and procedures that are used to provide this ‘dual-mode’ braking capability?
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?
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I think one Australian operator has vehicles
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 fi
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.
Here are the advantages that they cite in the article:
“Since installing EP-60 brakes, QCM trains have experienced a 5.7% decrease in fuel use and a 15% increase in throughput capacity. ECP brakes have virtually eliminated undesired emergencies, allowed an increase in average speed, and shortened stopping distances. Safety has been improved and component life lengthened (e.g., a 27% increase in brake shoe life). QCM has been able to increase train length from 156 cars to 182 cars without adding extra locomotives, and has been able to stop its practice of shortening trains to 100 cars and adding in-train compressor cars in the extreme cold.”
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.
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 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.