KI6WDX Wrote:
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> Okay, but why use the DTMF in the first place? If
> in the past the crew just called the dispatcher
> using the radio frequency for the area of the
> subdivision they were in, why not continue with
> that practice? The only time I heard the tones was
> when a MOW or ROW person(s) had to call whoever
> whether it was the dispatcher or another company
> person. Or are the crews using the PBX now as the
> old radio frequency they once used is changed over
> to the new digital format and the MOW/ROW people
> use their cell phones instead?

Actually, this procedure has been used for quite a number of years. It is colloquially known as "toning up" the dispatcher. In the many times I've heard this procedure used, the train or MOW crew have tried calling the dispatcher on the radio and have had no response. Perhaps the dispatcher has been involved in other radio calls or other duties and has not been able to hear this particular call. Once "toned up", the dispatcher's attention has been audibly obtained (hopefully) AND his dispatching console is now displaying a message that he has been toned and which radio base station has received the tone. The dispatcher will then answer with "UP dispatcher 56 (or whatever) answering Pine Ridge (or whatever) radio." Then the train/MOW crew will then communicate their message to the dispatcher. In Southern California, the procedure has been used, as I said, for quite a long time on the SP/UP, ATSF/BNSF and Metrolink.

Christopher Trentham
MP 5.7 on the PHL San Pedro Sub.