Page 1 of 2 1 2 LastLast
Results 1 to 10 of 16
  1. Default Repair lines severed by plane crash - a history project

    Featured Sponsor

    I'm looking for a description on how power lines might have been repaired in 1961. I'm totally beyond my depth, as will immediately become clear.

    I'm researching a 1961 plane crash that involved an airliner cutting high-tension lines. The powerlines are described as two powerlines with three heavy wires carrying 38,000 volts. The scale drawing shows seven wires - three on the west line, four on the east. The wires are stacked vertically and appear in the scale drawing to be about five feet apart. The official reports say the plane cut the lines at a 70 degree bank angle going from east to west. The plane's path was roughly at right angles to the two sets of lines. We have had some heated discussions on an aviation board about exactly how the power company would have dealt with the incident, and what kind of evidence this might constitute.

    What I'm looking for is a description of how a power company repairs lines that have been severed this way. I'm guessing they'd replace the entire length between towers, so they'd cut away at each tower, string fresh line between them, tension it and splice it. Would they cut away and replace more than that? Seems doubtful that the power company would trust the severed line to the extent that they'd put up a manlift of some sort, pull up both sides and tension it, and splice across the break. Sounds pretty awkward, too.

    Specific questions: If I'm correct about cutting away the lines, would the power company care at all about exactly where the break happened, or is that unimportant since they're going to discard/recycle the entire length anyway? I have no doubt the company would helpfully measure the break if the NTSB (CAB in '61) asked them to, but if the power company knew this was a plane crash would that lead them to measure the break without being asked? Would they start by coordinating with the NTSB (CAB) before touching anything? Would they tag each line for future reference at the tower before cutting it away? Any clue how this might have been done in 1961 and how it might differ from today? Six lines out of seven were severed on two rows of towers about a hundred feet apart. What kind of force (given a VERY sketchy description) would be involved in cutting each line?

    The incident in question is the crash of NWA flight 706 on Sept 17 '61 at Chicago. I am working with documentation that is woefully inadequate, but it's a long time ago and everything has been thrown away.

    I'm interested in documents or manuals covering this procedure, particularly standard operating procedures that might have been in effect in '61. I would be grateful for suggestions on researching the question further.

  2. #2
    Join Date
    Mar 2003
    Location
    Jersey
    Posts
    2,512
    Blog Entries
    1

    Default

    What conductor size? Were the adjacent tower arms damaged? You describe as towers, 38kv generally on wood poles but not always. In my experience, let it down on adjacent structure, splice and pull to sag.
    "It is not the critic who counts:The credit belongs to the man who is actually in the arena" Teddy Roosevelt

  3. Default

    Yes, they were wood poles, sorry for sloppy wording. I have no idea what the conductor size was, and the CAB report didn't mention any damage to the poles.

    In your estimation, faced with a set of wires cut by a crashing plane, would your company just go fix it, or would they contact investigating agencies and ask? It is part of the crash scene, after all.

  4. #4
    Join Date
    Jul 2005
    Location
    Florida in the winter Canada in the summer.
    Posts
    340

    Default

    Just fix it so the grid is back intact and the people have electricity. Any information needed by investigators would be documented by the power company.

  5. #5
    Join Date
    Mar 2003
    Location
    Jersey
    Posts
    2,512
    Blog Entries
    1

    Default

    I agree with Tramp, put it back up let the bean counters and engineering types investigate. surpising no damage to adjacent poles. I was involved in a small plane Cessna type aircraft taking down 230 Kv where the static wire ripped half the goats head off.
    "It is not the critic who counts:The credit belongs to the man who is actually in the arena" Teddy Roosevelt

  6. #6

    Default

    Quote Originally Posted by Orgnizdlbr View Post
    I agree with Tramp, put it back up let the bean counters and engineering types investigate. surpising no damage to adjacent poles. I was involved in a small plane Cessna type aircraft taking down 230 Kv where the static wire ripped half the goats head off.
    Bet he's having fun trying to figure out what a goat head is.....................

  7. Default

    Don't have a clue, but it's not vital that I get that. I'm very interested in the way y'all talk about the work.

    Can anyone point me to manuals or student materials or something that walks me through the whole repair process? Not that I'm looking for a new career, mind you.

  8. #8
    Join Date
    Mar 2003
    Location
    Jersey
    Posts
    2,512
    Blog Entries
    1

    Default

    I learned linework from the Journeymen that taught me, I as a Journeyman taught those who came up after me. Perhaps .01% was learned from books. That is Other than the now prescribed safety procedures that dominate the industry in ways we never dreamed of when I was coming up.
    "It is not the critic who counts:The credit belongs to the man who is actually in the arena" Teddy Roosevelt

  9. Default

    Ok, thanks.

    I watched a whole army of you guys down in Florida when I was doing hurricane relief work after Wilma. Thanks for that, too.

  10. #10
    Join Date
    Jul 2005
    Location
    Florida in the winter Canada in the summer.
    Posts
    340

    Default

    Featured Sponsorr

    Quote Originally Posted by CraigHagstrom View Post
    Don't have a clue, but it's not vital that I get that. I'm very interested in the way y'all talk about the work.

    Can anyone point me to manuals or student materials or something that walks me through the whole repair process? Not that I'm looking for a new career, mind you.
    Your best bet would be the "Lineman and Cableman's Handbook" by Kurtz.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •