Lehigh Line Train Crossing approach Frequency?

We were out railhiking today in Edison N.J. along the Lehigh line between Inman and Tingley and just happened to bring the scanner along to monitor the traffic in the area.
I was scanning frequency: 457.937/5 and I heard a short blip/transmission with no voice as the trains approached each crossing, something to do with the gate activation? As they seemed to transmit before the train actually arrived @ the crossings. If so it
Would be Kewl for me to monitor that frequency as I will know if there are enough trains in the area to go out for a hike and some pizza along the way!!

davebdawg wrote:We were out railhiking today in Edison N.J. along the Lehigh line between Inman and Tingley and just happened to bring the scanner along to monitor the traffic in the area.
I was scanning frequency: 457.937/5 and I heard a short blip/transmission with no voice as the trains approached each crossing, something to do with the gate activation? As they seemed to transmit before the train actually arrived @ the crossings. If so it
Would be Kewl for me to monitor that frequency as I will know if there are enough trains in the area to go out for a hike and some pizza along the way!!

What you heard has nothing to do with the crossing. It is a frequency on what an end of train device, a device that as I understand it monitors air brake line pressure at the last car and transmits the data to the locomotive. The EOT transponder mounts on the coupler and also generally has a flashing red marker light.

Ken nailed it down, for you. As the range on the EOT is limited to a scant couple of miles, you still have the answer. IF you are listening to this freq, and you hear the blip of the "ping" making the 2-way communication from the head-end to the EOT, then YES, a train is in the area. Might be easier though (and more reliable) to locate the nearest detector, and listen for it, instead.

Most EOT's are now two way devices and the associated locomotive HTD transmissions on 452.9375 are a better indication of an approaching train.

The 452.9375 transmission has greater range since the antenna is on the roof of the locomotive which is heading toward you as compared to the 457.9375 EOT sitting on the coupler on the rear of the train.

EOT and HTD transmissions are very brief so a scanner may miss them if you are scanning a lot of channels.

If you scan just the local road channel for the detectors and the HTD frequency you have a good chance of picking up both to alert you to a train in the area.