Re: Out Of Durango 5-26-1956

I for one find the old train orders crazy difficult to decipher! Al Krug, BN turned BNSF engineer, once posted some train orders on his webpage...the interesting thing for helpers out of Gillette WY was that their orders specifically forbade them from leaving locations until after they'd arrived!
The new track warrant type systems seem much more straight forward to me, but they require direct contact between dispatcher and train via radio. Which makes me wonder... how would a train crew communicate from head end to tail end and vice versa before radios? For example, after the two Durango/Chama freights meet at Ignacio, the inferior westbound has to re-enter the main, stop when the caboose is clear so the brakeman can set the switch for the main, wait for him to reboard, and then start west again. How does the tail-end let the head-end know when to stop and then restart? Or how would the brakeman relay hand-signals to the engineer when reassembling a Cumbres turn in a blizzard, at night?
Thanks,
Jason