Western Railroad Discussion > Hot box and dragger track circuits

How are the track circuits set up?  Counting axles, beginning circuits, equipment in shelter, etc

Mike Root
Madras, OR

Typically a short range track circuit, 200 feet or so. Transponders on the rail count the axles, direction. They also gate the balometers for heat detection, which are aimed at the bearings. The unit can be set up for various announcements depending on the railroad.

Posted from Android

The hotbox transponders and logic count the axles, no track circuits involved. Draggers don't have any way to count axles unless installed with a HB detector, in which case it's the HB detector apparatus which counts the axles, and the logic correlates the detection of dragging equipment with the HB axle count..

Incorrect.
Track circuit initialises the detector. I guess dealing with these since 1979 doesnt mean shit. Draggers can also count wheels without being associated with an HBD depending on RR. and application, such as the case of being installed with a high/wide detector, of which I had 2.

EtoinShrdlu Wrote:
-------------------------------------------------------
> The hotbox transponders and logic count the axles,
> no track circuits involved. Draggers don't have
> any way to count axles unless installed with a HB
> detector, in which case it's the HB detector
> apparatus which counts the axles, and the logic
> correlates the detection of dragging equipment
> with the HB axle count..

Posted from Android



Edited 1 time(s). Last edit at 08/28/15 13:51 by SP4360.

>Typically a short range track circuit, 200 feet or so. Transponders on the rail count the axles, direction.

Went back and looked. The OP's question was poorly formed because it could all too easily be taken to be asking whether the track circuits count the axles, which they don't.

If what you say is true re those 200' track circuits, then why in 41+ years of railroading have I never seen one for a stand-alone (no transponders present) dragger? Yes, they are wired into the signal circuits in some way (trip a signal, illuminate a letter type indicator, turn the device on, etc.).

>Draggers can also count wheels without being associated with an HBD depending on RR.

Yes, unless the RR buys (and installs) the transponder apparatus to do so, there can be no axle counting for a stand-alone.

I hate to say it but at least on the Brooklyn and Cascade Subdivisions of the UP the "stand alone" dragging equipment detectors DO give an axle count to the defect, or at least the majority of them do and I'll bet they all do. I would assume detectors throughout the UP system do the same thing as well.



Edited 1 time(s). Last edit at 08/28/15 20:39 by Railbaron.

Railbaron Wrote:
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> I hate to say it but at least on the Brooklyn and
> Cascade Subdivisions of the UP the "stand alone"
> dragging equipment detectors DO give an axle count
> to the defect, or at least the majority of them do
> and I'll bet they all do. I would assume detectors
> throughout the UP system do the same thing as
> well.

Correct. The easiest way to know for sure, other than hearing them on the radio, is to look at the timetable special instructions for a particular division. You  will see something like DE with axle count.