BNSF Detector Rebroadcast

[N9JIG]

I live a few miles from a BNSF line and can usually hear the local detector. Recently however every time I hear it is announces as "Rebroadcast, BNSF Detector Milepost xxx.x..."

Is this some sort of error at the detector where the normal recording is not being selected?

Has anyone else noticed anything like this?

 

[AK9R]

Is the detector you are hearing rebroadcasting another detector's message because there's a chance that, in mountainous terrain, the train may not be able to hear the original broadcast?

 

[N9JIG]

I don't think so. I asked elsewhere as well and it might be that the detectors only talk upon defects or when requested by the crew. I presume if this is the case they have a DTMF code or something they send to get the replay.

If this is the case it is fairly new here, they used to just talk on every movement.

 

[Tim-B]

I recently heard a detector do a rebroadcast but it was because a train crew made it do so. Here is what happened: Amtrak passed the BNSF detector in Broussard, LA (BNSF Lafayette Sub, Milepost 138.9) and it gave them a number code for a certain type of defect. The dispatcher called them on the radio and told them that type of defect requires them to stop the train as soon as they reach a place where they can do so and set that car aside for maintenance. The crew checked the axle identified and did not find a hot box or any other bad condition. The train continued on and the next detector near Duson, LA (BNSF Lafayette Sub, Milepost 154.3) said no defects. The crew did a DTMF code on the radio and the detector rebroadcast no defects. The dispatcher said they could continue on and stop and check it again in 10 miles. They stopped the train near Rayne, LA and checked the axle in question and others and told the dispatcher they were cold to the touch and no defects found. They probably toned up the detector to do a rebroadcast as a CYA thing so they could put in their report that we checked it twice and it said no defects. I have heard the detectors many times and that is the only time I ever heard a rebroadcast. The train crew toned it up with DTMF to make it do so.

 

[marlin39a]

I get the defect detectors on the Phoenix Sub at 23.5 and 46.9. I’ve never heard a rebroadcast.

 

[wa8pyr]

I live a few miles from a BNSF line and can usually hear the local detector. Recently however every time I hear it is announces as "Rebroadcast, BNSF Detector Milepost xxx.x..."

Is this some sort of error at the detector where the normal recording is not being selected?

Has anyone else noticed anything like this?

Is the detector you are hearing rebroadcasting another detector's message because there's a chance that, in mountainous terrain, the train may not be able to hear the original broadcast?

Detectors don't repeat each others' findings, but train crews (and presumably the dispatcher etc) can cause the detector to rebroadcast the last message. This happens with the detector near my office occasionally after a train has gone by it; my guess is that the crew was busy babbling to each other about the big game and didn't quite catch what it said, so they made it repeat.

 

[jbhunt04]

I have heard the DD in Breton, KY(CSX mainline), do a rebroadcast once or twice, there was always three DTMF tones first. I’m not sure if that was the crew doing that or the detector doing so automatically. But whenever it did, it was when there was quite a bit of radio traffic on the road channel.

 

[chrismol1]

Is it true, we know the detectors store the information, that sometimes theres is a connection back to the network where the dispatcher can bring up that information? I seem to recall hearing once the dispatcher "look up" that info

 

[wa8pyr]

Is it true, we know the detectors store the information, that sometimes theres is a connection back to the network where the dispatcher can bring up that information? I seem to recall hearing once the dispatcher "look up" that info

At least some certainly have that capability. Back in the day some detectors were connected back to the dispatchers office via telephone lines or lineside wires, and printed out the results on a paper strip chart showing a line as the train went by, with a spike or something to indicate an anomaly.

With the data-handling capabilities of PTC, I wouldn't be at all surprised if defect detectors were part of that network.

 

[FrensicPic]

I believe some detectors have the capability to repeat ("rebroadcast") the last transmission.
The engineer can cause that to happen by transmitting the appropriate DTMF code.

 

[wa8pyr]

I believe some detectors have the capability to repeat ("rebroadcast") the last transmission.
The engineer can cause that to happen by transmitting the appropriate DTMF code.

As mentioned in an earlier post...