Inspect Train Signals

NW Mailing List nw-mailing-list at
Mon Apr 21 12:44:06 EDT 2014

There several of these signals on the Columbus District I recall seeing.

Based on conversations with train crews and the timetables of the era
(early 1980's) and before the advent of talking detectors, these signals
were pretty common.

At the time, defect detector read outs basically looked like an EKG machine
tape...the squiggly lines were for each axle. I believe I have a section of
one somewhere at home in the files. As a train went over the detector, this
tape would roll out...the dispatcher would then visually read the tape to
see if there were any anomalies.

If a hot bearing was indicated, the squiggly line would peak well above the
"normal" line, alerting the dispatcher to have the train stop and inspect.

The "Inspect Train" signal was the dispatchers way of letting a train know
the status of that detector read. I believe they were normally set to red,
which would tell a train to call the dispatcher and prepare to safely stop.
Most of the time, the dispatcher would read the tape prior to the train
seeing the signal and turn it to green, but I recall many time hearing a
train call the dispatcher with a red inspect train light only to have the
DS come back, "make it green".

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