"Train Too Slow"

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pinballwiz86

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So I was listening to the BNSF train conditions frequency as it goes by.

Usually it says, "No defects. No defects. Train axle [something] out."


But this time it said, "train too slow."


Why does that matter? And is there a list of all the warning messages online?


Thank you.
 

W8RMH

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I don't know but I would guess that the train has to be at a certain speed for the detector to properly work.
 

reconrider8

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The way the one here is is just about like that but it says "No defects, no defects end of transmission" then in like 10 sec of so it will give the Axel count
 

burner50

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The train must be moving so fast for the detector readout to be accurate.

Usually UP detectors will announce "Integrity Failure" if the train is too slow.
 

Josh

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When a train goes under, perhaps 8 or 10MPH, it should trip the "too slow" message if it's enabled.

Wheel counting transducers are typically passive devices. The faster the wheels go over them, the stronger the sine wave produced by the magnetic coils- very much similar to an electric guitar. At the slower speeds, the electrical pulses can be too small to reliably count. This can result in inaccuracies if there were to be a defect. Too many miscounts can lead to an integrity failure message.

I heard this on an Amtrak train because the train stopped to flag through a crossing, after the "train too slow" was broadcast, the crew treated it like a malfunction and did an inspection on the ground, but I don't see freight trains doing that.
 

RRR

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I maintain crossing signals and defect detectors, the older Southern Technologies DED/HBD units would "time out" over and over if the train went too slow, as it kept wanting to end the readings, and send the message.

there are settings where you can set the delay between axle readings, maybe an adjustment is necessary, or maybe the train was barely crawling. But it is a proper announcement.
 

k6cpo

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Some of the detectors aren't terrible accurate. I was on Amtrak's Coast Starlight on a trip from LA to Seattle and somewhere between a pair of detectors we lost a pair of axles on the train... :lol:
 

burner50

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A pair isn't such a big deal.

A variance of more than 3 may be a cause for some concern.
 

N8DRC

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So I was listening to the BNSF train conditions frequency as it goes by.

Usually it says, "No defects. No defects. Train axle [something] out."


But this time it said, "train too slow."


Why does that matter? And is there a list of all the warning messages online?


Thank you.
I heard the detector say that a couple times this past summer when the crews were doing maintenance on the tracks..Only time I ever heard that..
 
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