So here's a problem: You operate freight service over a commuter railroad's main tracks. The commuter railroad has opted to install ACSES II or a version thereof to comply with PTC requirements.
In your operation, your freight locomotives move most of the time with cars over the commuter railroad's main tracks. Sometimes the locomotives have to move "lite," without cars over the main. Your locomotives are equipped with the bail-off feature for the independent brake, releasing the brakes on the locomotives when braking a train, a handy thing to have to prevent run-ins, flat wheels, etc during brake applications, particularly of the unintended, or penalty, kind.
Now how do you prevent the utilization of the bail-off feature when the locomotives are operating without train, because you know, bailing off the brakes plays havoc with braking curves when there is no trailing tonnage. And...there just might be that one in 34,000 out there who thinks it would be great fun to override a penalty brake application by bailing off the locomotives and skating to Valhalla, or Armaggedon, non-stop. Believe me, it could happen.
Well, our mission, should we choose to accept it, requires us to develop a means for disabling the bail-off feature on your locomotives when operating without train, but enabling the bail-off feature when the locomotive is operating with train. The enabling/disabling has to be automatic, capable of "toggling" between enabled and disabled an infinite number of times. It has to be accurate, distinguishing correctly between the lite condition and the with train condition. And.......the toggling must be independent of the locomotive engineer's, or any crew member's, operation of a selector switch, or "cut-in/cut-out" mechanism, or valve, or "soft key." The disable/enable action must be more than tamper resistant; more than tamper proof. It has to be part of the locomotive's automous control system, inaccessible to operator intervention.
As always, should you or any of your Bail-Off Force fail, the Secretary will disavow any knowledge of your actions.
ACSES can't do this work for you. If it could, we wouldn't be discussing this.
I used to think that all questions on the railroad are questions of "Who's In Charge?" I still think that, but sometimes the answers require a bit more nuance. Sometimes all the questions are really questions of information, or signal. How do we signal the on-board locomotive control system that in one instance locomotive 1234 is operating lite, while in another instance locomotive 1234 is operating with train?
Do I have the answer? I'm not sure, but I think I have a glimmer of answer, and that answer begins with the EOT (end-of-train device), in this case, or these cases, "smart" or "two-way" EOTs that communicate information, data, about the brake pipe pressure via radio telemetry between the device located on the rear car at the rear-end-of-train, and the device located in locomotive located the head-end-of train (HOT device).
Once this communication is established, we have the signal that can be processed to "toggle" the control of the bail-off between disabled and enabled.
Obviously in our "system," the default condition, is the absence of telemetry between head end and rear end, bail-off disabled. It takes the detection of the signal, continually refreshed, to enable the bail-off feature.
Does this prevent a crew from attaching the EOT to the trailing end of the lite locomotive consist and merrily bailing-off all the way home? No. But...that will be your next challenge.
Brought to you as a public service. This idea is not patented or trademarked or otherwise protected from being lifted, taken over, refined, and made practical. In fact, please do. Just give me a mention in a footnote...a birthday card would be nice, too.
David Schanoes
September 13, 2019
How can it not know what it is?-- Deckard, Blade Runner
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