N&W icons: the singularly N&W 440-volt line on poles

[nw-mailing-list at nwhs.org]

I talked with a couple of retired N & W Signal Department people about this subject to be certain that my feeble memory was correct.

The offset bracket on the top of signal line poles is called a "bayonet."  It carries a "ground" or "static" line that is grounded at every fourth or so poles by a wire that runs from the static line down the pole to a stake in the ground.  The purpose of the static line is to provide a low resistance path to ground for lightening strikes.  The purpose of the offset in the bayonet is to accommodate the insulator and one wire of a three-phase, 4400-volt signal power circuit on top of the pole.  The two other wires of the three-phase circuit are carried on insulators at either end of a cross arm below.

Gordon Hamilton
  ----- Original Message ----- 
  From: nw-mailing-list at nwhs.org 
  To: N&W Mailing List 
  Sent: Monday, July 31, 2006 10:36 PM
  Subject: RE: N&W icons: the singularly N&W 440-volt line on poles


  Wrote Lloyd Lewis:
         My Dad, who was The Virginian Railway's last Supervisor of Telegraph & Signals, told me this extra wire on the N&W's pole line above all the other numerous lines and crossarms was the perch upon which rested a special N&W-only 440-volt line....


  Doesn't add up for me, Lloyd.

  1.)  Where's the other side of the circuit (the "neutral" or "return" wire) ?

  2.) 440 isn't enough juice to go very far.  I haven't done the calculations, but I'll bet you'd see a 50% line drop in voltage over a hundred miles.

  3.)  Other railroads, and mebbe even the N&W, were hanging 4,400 volts on poles and using it to light stations and drive AC signal systems, as early as 1911-1913.

  4.)  CTC code line is almost invariably shielded (insulated) because of its critical importance.

  I hope one of the museums can get a couple of N&W poles, crossarms and wire, and two of those distinctive angle brackets !

  -- abram burnett


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