Station names (was "Kumis" topic)

[NW Mailing List]

I feel compelled to mention that names and numbers were NOT spelled out during the transmission and repetition of Train Orders in telegraph days. 



That "spelling out" was something introduced when the telephone came into train dispatching.  Railroads did not really trust the fidelity of the telephone for something so critical as directing the movement of trains.  The "telephone amplifier" was not introduced on the railroads until about 1917, so you can understand the problem.  (Audio amplification was impossible before Lee DeForest invented his "radeon tube" (which you know as the "vacuum tube") in 1906, and it took a few years to work its way into the railroad business.)  



Look at some of the Rule Books of that period and you will see things like, "When Train Orders are transmitted by a telephone, the following precautions must be taken..." 



Unamplified "talk voltage" didn't travel very far before the signal was attenuated.  Before tube amplifiers, railroads tried to address this  "line loss" or "voltage drop" problem by inserting torroidally wound "load coils" (a.k.a. "repeat coils") at intervals along a line.  But since no energy was added to the circuit at the load coils, voltage was boosted a bit but current went down.  So telephones weren't very effective over long distances.  If you want to see load coils in use, visit my basement... 



-- abram burnett 

curmudgeon-at-large 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://six.pairlist.net/pipermail/nw-mailing-list/attachments/20120225/564eee46/attachment.html>