[GreenKeys] Open lines?

[kf9nz at juno.com]

       When I first went to Colorado in 1956. Moutnain States Bell had
beautifully maintained open wire leads all over the state.   Four years
later they were all gone.   

        Yes, transpositions were important.  On the railroad we had open
wire into the late 90's, but they were very hard to maintain.  Wire
thieves drove us crazy.   As construction, especially of highways,
increased, the standard procedure whenever a new highway crossing,
overpass, underpass was constructed was to install an underground cable 
through the construction area and not renew the pole line.  This of
course made the transposition sections a joke.   One hunk of railroad in
my territory had repeated complaints from the Train Dispatcher about the
noise.  He had to listen to it from a loudspeaker his whole shift.   I
had linemen running up and down the line  looking for high joints,
crosses etc.    An engineer from headquarters came down to look at it.  I
took out my transposition map and laid it out with all the little cable
sections marked out.  I didn't have to say another word.

        Of course there were phantoms in cable circuits too.  The pairs
were transposed around each other in a "quad".   WU had lots of quadded
cable,  9 and 16 gauge wire.

Frankf9nz  
 I have been perusing my copies of the greenbooks, (I have the last
 two, and am shopping for the first two), and was fascinated by the
 fact that the longlines engineers would phantom a third call upon two
 pairs of open lines. I have several questions about this.
    

  
 First, are there anymore open line circuits still in operation?
    

I can't speak for the US but there are open line circuits on rural 
railways in the UK.

  
 Second, if there are say four pairs of wires, ("sides"), could you at
 least theoretically phantom up to six other calls on those four
 wires? One phantom circuit between each possible pairing of pairs so
 to speak.
    

If you think about it Joe, the answer must be no. It would be like 
saying you could make six circuits with four wires - 1&2, 1&3, 1&4, 2&3, 
2&4, 3&4. The circuits that share a wire interfere with each other, 
which ends up being all of them.

However, it was practice to generate a phantom on a pair of phantom 
circuits. So your four pairs could generate two straight phantoms and 
single double phantom. So your four pairs could generate seven circuits. 
I recall that making phantom circuits work properly over long distance 
required great attention to wire transpositions along the pole route.

Cheers,
Sam
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