Dick Samuels, owner and operator of the Oregon Pacific Railroad, explains that here for his specific shortline:(never heard of them activating crossing circuits).
Dick Samuels, owner and operator of the Oregon Pacific Railroad, explains that here for his specific shortline:
Altamont Press Discussion Board :: Discussion :: Re: Oregon Pacific Railroad's GMD-1 in Snow Action - Video link
At about 24:29 in the video they are discussing, you can see the sticky that shows the specific tones for each street (only two, in this case).
Good friend of mine and my family was a new signal maintainer back in early nineties . I still remember the look he gave me when asked if his supper was good last night and told him what all he had. He asked how did I know that. Told him everything he said over the radio comes across any scanners or radio's. He turned RED the next night he worked when he called his wife first thing said right off was that he was on the radio phone. LOL He did that every time he called her until they phased out using the PBXBack in the day railroads used to use PBX (Private Branch Exchange). Basically it was a phone-to-radio-to-phone interface where a special code is dialed to access the PBX, and then the phone number is dialed all using DTMF tones. CSX used to use it to call signal maintainers, yard masters, ect.
Listening to the Lancaster/Tehachapi feed on railroad radio.net and am hearing DTMF (phone) tones.
What purpose do they serve?
Yes, that's one use, as previously discussed in this very thread.The three digit DTMF tones are in fact used to light a light and sound a tone in the dispatcher's pod at the Harriman Center (or BNSF's dispatch center in Tx) to let them know somebody needs to talk to them.
A good dispatcher will listen to as many radios as possible. In fact, many times while fueling, the fuel truck reports clear, and the dispatcher will go ahead and hang me a light before I can even get him toned up. He's monitoring the radio.They don't normally listen to all the chatter that goes on and for good reason:
That's true in some situations. On the UP, all towers in a certain area have the same tone, and often when you tone the dispatcher, you'll hear multiple towers tone back. I've been on the BNSF before when trying to reach the dispatcher tone up a certain tower, and if the dispatcher is unavailable, I'll be out of range before he comes back to talk to me.So the solution is: each Base station has a DTMF tone decoder that has a unique code to trigger it. The train crews know what that code is.
Almost, but again, you're speaking in absolutes, and on some major railroads, that simply is not true. In almost all cases, if you miss the report, or it is otherwise unintelligible, You don't have an option to have it read back to you. You simply tone up the dispatcher and he either pulls up the detector results, or calls the desk in charge of inspecting detector readouts, and returns with the results a moment later.The train crews can also send a different set of DTMF tones to a detector and have it play back the details of the last test. This is so they can confirm what they think they heard..