CN ORDERS HIGH-PRODUCTIVITY END-OF-TRAIN DEVICES FROM WABTEC RAILWAY ELECTRONICS: Wabtec Corporation today announced that its Wabtec Railway Electronics unit has received a $5 million order for more than 500 high-productivity end-of-train (EOT) devices and related equipment from CN, the largest railroad in Canada. These EOTs, called TrainLink™ ATX ES, enable locomotive engineers to perform braking applications simultaneously at the front and the rear of the train for both emergency and service (regular) braking. Delivery of the devices began in the fourth quarter of 2004 and will be completed in 2005. “After testing this model of EOT for several years, CN is making a major commitment to a Wabtec technology that combines traditional pneumatic braking applications with electronics,” said Robert P. Haag, vice president of programs for Wabtec Railway Electronics. “This technology improves train handling, braking control and fuel efficiency, as it reduces in-train forces and the potential for lading damage. It’s an example of how Wabtec is helping railroads improve the efficiency of their operations by providing incremental technological advancements that offer appropriate financial returns.” The devices include integrated Global Positioning System technology for advanced tracking and train control. TrainLink ATX ES units are powered by a small turbine generator, rather than a battery, which reduces maintenance time and cost, as well as train delays. “CN looks at the partnership with Wabtec as a catalyst for innovation,” said Sameh Fahmy, vice president of mechanical, engineering and supply management for CN. “In the past three years, for example, CN has acquired tens of thousands of TreadGuard™ brake shoes, which prolong wheel life and are made by Railroad Friction Products Corporation, a Wabtec subsidiary. We are now making a substantial investment in new-technology EOTs to improve train handling, and reduce failures, maintenance costs and, most important, train delays.” (WABTEC- posted 5/04)
The problem with these ATX EOTs is that you have to have them hooked up to the train line before you can find out if they are any good or not, because they are powered off of the air.
Get’s anoying if you have to hook a bunch of them up, and it turns out that the whole pile is bad order.
Whereas the ones that run on batteries can be tested from anywhere, just pu***he buttom and they light up, so you don’t have to hook them up to the train to find out if they are any good or not.
Of course the ATX ones are much lighter, because of the lack of huge batteries.
I can understand why you would want the EOT to dump air in an emergency application. But I wonder about the service applications. I don’t run trains so I don’t know. It just strikes me as something that would make slack action less predictable. One end would be bunching up and the other streaching out untill the application is equal throughout the train. How do you engineers feel about service apps from the EOT?
CP (and a few other RRs) runs a lot of trains with Robot loco’s on the tail end, for such reasons as better train handling and less slack action.
Basically this EOT is now allowing hoggers to set the brakes up on the tail end, it’s a start, but still not as full featured as running a robot loco on the tail end.
it is supost to make a faster brake application… by venting air at both ends at a service rate it makes the brakes set up faster for quicker stoping…
csx engineer
Correct. Hopefully it will also make the brake applications more uniform. Think of a train as a giant bullwhip. Putting it into emergency without an EOTD vents the air ONLY at the locomotive. Thus as the wave of the emergency reduction travels down the train it is like cracking the whip as the slack runs back as each car brakes in turn. By venting at both ends the rear of the train also begins slowing at the same time keeping 'em on the rails by reducing the wave of slack. I hope we get some of these new EOTDs, I want to try one out.
LC
Does that but too much stress on the couplers?
Keep in mind that one of the things a 2-way EOT device does is to provide a second pressure wave of air to the triple valves on the cars in the train. Modern brake systems will apply based more on the pressure differential (or rate of change in falling pressure) than on the absolute pressure at any given moment in the train line. A fast brake application will send a ripple of pressure down the trainline at or near the speed of sound in compressed air, which toggles all the triple valves that are sensitive to the magnitude of the pressure excursion in the ripple. When you have an EOT that uses a radio signal, propagating to the rear air valve at very nearly lightspeed, to mirror the modulation of the brake valve at the front of the train, you cut in half the time it takes for the pulse to reach, and presumably activate, the triple valves on all the cars.
Now, if only there were consistency in the way in which the air cylinders, linkage, and shoes producedcomparably precise braking effort to each truck of the cars in the train… and were adjustable to the weight, draft-gear type, etc. of the cars so that braking force for empties would be proportional to that for loads. The modern proportional EP brake systems can do this sort of thing; it’s technically possible to approximate it with a mechanical setup – but only by introducing expensive complexity, and a need for much more intensive and precise maintenance than would be possible (imho) for interchange cars.
so it sounds to me like dumping the air from both ends during emergency braking could reduce some of the dynamics that can cause derailments during an emergency brake application – is that right?
dd
In general terms, yes. That was the idea of the earlier EOTDs that allow an emergency application from the rear only. Hopefully, this new version will enable the engineer to avoid the need for an emergency application at all in some circumstances and should be a real help with heavy trains in grade territory.
LC
This sounds o.k for the newer cars but does this work o.k for the older ones? My concern is the coupler system. If a hundred car train of CN pulled by a couple of locomotives goes into emergency, would the force of the stop be like 200 or 250 cars of force depending on the loads? Wouldn’t this but an enormous amount of strain on the middle of the consist like the robe in a tug-of-war contest?
Current rules require the engineer to activate the EOT emergency valve whenever the train goes into emergency, whether it caused by a trainline separation or engineer action. Some locomotive are setup to do this automatically.
Handy to dump the air on the rear , especially when a stack car has a kinked hose 5 cars behind the engine. Ala Cajon pass.
Randy
Andrew -
That’s not the way it works. If anything dumping the train from both ends reduces dangerous in train forces much faster than dumping the train from the head end alone. While it is still possible to have a pile up of cars in the center of the train, especially in trains of mixed freight, the stress on the drawbars is significantly reduced, not increased as you suggest. If the engineer dumped the train from only the rear, this could cause overstress on the couplers and one or more failures.
LC
Would having the higher end EOTDs speed up braking even if you have a cut in helper or is it just the same?
Thankyou for the response. The way I interpreted it was that the dumping of air from both sides would cause a anchor at both ends causing either an accordian like effect or a tug-of war like effect. Plus the description of the “bull whip” made me concerned.
Does anyone know if these are being developed in Wabtec’s Wilmerding ¶ plant? Good to see more positive news coming from Wabtec.
If there are no batteries what keeps the light working when you go into emergency and there is no air to run the turbine? The light really isn’t needed when moving, but it helps to protect the train when stopped.
Good point. There must be some kind of short term battery.
Well, when it vents air for emergancy, it could use that to spin a turbine, or maybe it does have a small battery…
Anyone know of a site that has info on these magic boxes?