Do the ATS Boards along the mainline stand for Automatic Train Stop? And if so how does the engineer acknowledeg it on todays motive power? If I remember there was a small lever or switch that was thrown in the cab after passing the ATS Board. Is it still the same?
ATS is indeed what you think it is (Automatic Train Stop)…This is what allows you over 79MPH on the territories with a higher speed rating. They are usually set in advance of a speed restriction (curve, yard limits, crossing, junction switch and so on)
A brake pipe service reduction is what kills the whistle or alerter.
Zardoz might be able to shed some light here–he worked in CNW’s ATS territory (now restricted to Chicago-Harvard and Chicago-Kenosha). There was a contact shoe at each block signal–anything less than a clear indication had to be acknowledged, done with a separate lever in the cab.
ATS territory was more widespread when I caught some Wisconsin road jobs–probably Chicago to Green Bay (via downtown Milwaukee only–not via Butler) and Butler to the Twin Cities. There would be test shoes at any entrance to the territory, so we’d hit one at the distant signal for St. Francis in either direction on the New Line.
If the alerter is not responded to how is the train stopped? How does the devise cause the train 's braking system to set up and stop the train?
It’s tied in with the brakes to cause a penalty application (train will stop; a penalty application cannot be released until it has).
When you get a penalty brake application, besides giving a full service application, it opens up the PC (pneumatic control) which reduces power to idle. To recover, you place the automatic brake valve in suppression and, like Carl said, come to a stop before releasing. Some of the newer engines will show on the computer screen how long to remain in suppression before attempting the release.
Jeff
I am also interested in the answer to this question: How does the device communicate with the train’s braking system? Is it through a microwave communication system? Or radio frequency? How susceptible is the communication channel to hackers?
I would say it dumps a full brake applications worth of air out of the equalization air tank. But that’s just a guess.
In ATS territory, an inductor is mounted on the ties in advance of each block signal. Unless the signal is clear, current flows through a coil in this inductor.
Locomotives operating in ATS territory are equipped with a receiving shoe, mounted on the truck just outside one axle bearing, in a way that the shoe passes over the ATS inductor at each signal (clearance between the two is about an inch and a half). If the signal is other than clear, the current flowing through the inductor’s coil reacts with coils on the receiver, causes a relay on the locomotive to trip, actuating the brakes (unless the engineer acknowledges the signal by moving his lever, which prevents the relay from actuating–a timer prevents the engineer from just holding down the lever more than a given length of time, after which the brakes would apply). When the shoe passes over the industor and is properly acknowledged, a short whistle is heard in the cab.
No fancy microwave or any other communication is involved–this system predates all of that. There might be ways to sabotage the inductor, but one hopes that the engineer is observing and responding to the wayside signals anyway.
Thanks for the explanation. That clears up a lot.
The light rail system here also uses inductors on the roadbed between the rails. I don’t think that they are part of an ATS system, but I wouldn’t know for sure.
Thanks again!