Train defect detector

[N1XDS]

I am learning about the train lingo and what all it means so here's one of the questions I have...My local railroad track that is down the street from me has a train defect detector but I never hear it when a train passes thru the area..From what I am finding out detector is set to talk on defect only: (No)... So does that means I won't hear it? The railroad track is about 1.5 mile (3 minute drive from me) so I should be able to hear it if I would be able to. Yes, I have the frequency it uses programmed in to my scanner.

- Jamie

 

[buddrousa]

All of the CN Defect Detectors Talk every train. Direction of Travel, Temperature, Number of Axles, Speed and No Faults.

 

[sallen07]

The defect detectors I am familiar with (including the ones I can hear from my house) "talk" whenever a train passes over them. This gives the crew a positive indication that there are no defects. But that doesn't mean you are wrong about the one near you.

If it really does only talk if there is a defect, you will very rarely hear it. I only occasionally listen to the ones near me, but in the last five or ten years I've heard hundreds of "no defects ... no defects" and maybe TWO hotbox reports.

The transmitters for the detectors are low power (they are for the train crew's benefit) but I would think you could pick that one up from 1.5 miles away unless there's a mountain in the way. The ones I can hear are about 2.5 miles away. I can easily pick them up with an outdoor antenna; with an HT it's hit-or-miss.

 

[sallen07]

All of the CN Defect Detectors Talk every train. Direction of Travel, Temperature, Number of Axles, Speed and No Faults.

The ones near me are CSX, and as I said in my first post they talk every train. Milepost, track (there are two), number of axles, "no defects".

They must have been replaced a few years ago, because they USED to include train speed but no more.

 

[N1XDS]

Most of the trains that pass thru here in the early morning times and mid afternoon times are mostly Norfolk Southern trains. I am running the SDS100 with an outdoor DPD Productions Omni X outdoor antenna in my backyard about 40ft up in the air with nothing blocking the incoming signal I can pick up the dispatcher with no issues. Maybe or maybe not the power on the defect detector is set really low so maybe that is why I am not able to hear it unless they changed the frequency to it but I don't see anything about it.

 

[jmumford]

I am learning about the train lingo and what all it means so here's one of the questions I have...My local railroad track that is down the street from me has a train defect detector but I never hear it when a train passes thru the area..From what I am finding out detector is set to talk on defect only: (No)... So does that means I won't hear it? The railroad track is about 1.5 mile (3 minute drive from me) so I should be able to hear it if I would be able to. Yes, I have the frequency it uses programmed in to my scanner.

- Jamie

What railroad is it?

 

[N1XDS]

What railroad is it?

All I can find via google search is Norfolk Southern Railway at mile post 212.0 Powersville

 

[wtp]

maybe a directional antenna ?

 

[AK9R]

Yes, defect detectors usually have low power transmitters. But, they still need to be heard by the head end of a two-mile-long train after it passes.

In my experience, a defect detector that only talks if a defect is detected is pretty rare. Most of them transmit a brief announcement as the train is passing so the train crew knows that the detector is working. If the DD is not working, the rules usually require that the crew stop and inspect the train and/or report it to the dispatcher.

DDs are usually on the road channel, not the dispatcher channel. Make sure that you have the road channel for that area programmed into your radio.

 

[jmumford]

All I can find via google search is Norfolk Southern Railway at mile post 212.0 Powersville

OK, thought it might be BNSF as a lot of their detectors are set up only to transmit on a defect.

 

[N1XDS]

Yes, defect detectors usually have low power transmitters. But, they still need to be heard by the head end of a two-mile-long train after it passes.

In my experience, a defect detector that only talks if a defect is detected is pretty rare. Most of them transmit a brief announcement as the train is passing so the train crew knows that the detector is working. If the DD is not working, the rules usually require that the crew stop and inspect the train and/or report it to the dispatcher.

DDs are usually on the road channel, not the dispatcher channel. Make sure that you have the road channel for that area programmed into your radio.

Made sure that I have the right channel for it and I do from what it shows on defect detectors website. In the past couple of days I am picking up 220.7675 Railroad PTC-7 Base.

 

[EAFrizzle]

I'm a couple of miles from a UP track, and I've never heard any of the trackside DDs report. I can hear the trains fine along a good length of that line. I do often hear the overspeed detectors in the yards signaling the track numbers, but they're obviously on a normal power rig on a tower.

 

[Railbender]

I am about 1.8Mi from the NS DD. It reports its MP location and "No defects" in two transmissions a few seconds apart.

 

[N1XDS]

When listening to a defect detector frequency does the modulation have to be set in anyway? Like FM or NFM modulation analog or digital?

 

[AK9R]

As far as I know, all railroad voice transmissions, including defect detectors, should be narrow FM.

 

[burner50]

All of the CN Defect Detectors Talk every train. Direction of Travel, Temperature, Number of Axles, Speed and No Faults.

*ALL* of the CN Defect Detectors Talk to EVERY TRAIN?

I doubt that greatly. I'm sure that there are some that either talk on defect only or don't transmit voice communication at all just report to dispatch.

 

[wv9m]

It appears that the NS mainline running through Byron, GA is in the Norfolk Southern Brunswick District as this line runs northeast to Macon. You should be hearing the detector voice traffic on road channel 36/36 (160.650 MHz). Wasn't sure if you had this programmed, was not mentioned in previous comments.

See this RR reference: Georgia Railroads (Georgia) Scanner Frequencies and Radio Frequency Reference

220.7675 MHz is positive train control (PTC) telemetry. Thanks for mentioning this, going to do more research and listen when I travel. The FCC took the lower segment of the 220 ham band from us a while back. Heard that it was assigned to UPS, but this sheds more light on the rail industry communications.

 

[buddrousa]

@burner50
Sorry to offend you as I only have the 15 to 20 in the area I travel of CN's.

 

[ak7an]

On the UP it depends on what type of DD it is whether it is ”talk freely”, which talks every train with an entrance and exit message, or “talk restricted “ , entrance message only , or “talk on defect only”, self explanatory. Most Hot Box detectors are ”talk restricted “, except for the ones near the yards which are “talk freely”. Stand alone dragging equipment detectors or wheel down detectors are almost always “ talk on defect only”.
Hope this helps with UP detectors.
Take care
Ed

 

[burner50]

@burner50
Sorry to offend you as I only have the 15 to 20 in the area I travel of CN's.

I'm not offended, I just know that it's pretty common to have detectors that don't transmit voice communications for every movement over them.