Disassembly of a crank-up tower

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by KI7HSB, Oct 28, 2018.

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  1. KI7HSB

    KI7HSB Ham Member QRZ Page

    Despite hours of searching the internet, I cannot find even a single reference to, or instructions on how, to separate the sections of a crank-up tower. Is this an impossible thing?

    I just acquired a TRI-EX LM-354 that needs a thorough cleaning, rebuilding and removal of a well meaning, but poor paint job. I thought it would be easier if I could work with each section separately, not only to better access all the nooks and crannies, but to make the whole easier for just me to move around cuz 1 tower segment weighs a helluva lot less than 3...
     

    Attached Files:

  2. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    With the cables disconnected, I think you can just pull each section out from the one behind it; although maybe there are "stops" welded in place to prevent that (I really don't remember).

    I don't know why there would be stops installed, though; when they "hot dip galvanized" these they do it one section at a time after all the welding, so the welds are also galvanized.
     
  3. WA7PRC

    WA7PRC Ham Member QRZ Page

    My US Tower TX-472 has stops welded in place.
     
  4. N7WR

    N7WR Subscriber QRZ Page

    The U S Towers I have owned (a few) all had welded stops that prevented the sections from being pulled apart
     
  5. KI7HSB

    KI7HSB Ham Member QRZ Page

    There are stop blocks welded to the outer corners of each section at the top to prevent it from falling down into the next larger section any farther than design. However, the tops of the outer and bottoms of each inner section are crimp formed into matching "shoe" shapes to act as guides and first glance geometry says that they won't slide out the top either... It just LOOKs like there's no way to separate them.

    1028181322a_resized.jpg
     
  6. KI7HSB

    KI7HSB Ham Member QRZ Page

    It is looking as though if I want to work with each section individually, the only way to do that is to manually extend the tower horizontally on sawhorses on the ground... That means that it's not leaving my driveway again until I have all my buddies over for a tower moving party.... :(
     
  7. WA7PRC

    WA7PRC Ham Member QRZ Page

    The only point my tower could be delivered to was in my front yard. Using pneumatic yard equipment wheels/tires rated 400# each, I cobbled together a pair of trucks to move the tower into my back yard using Manuel Power:
    [​IMG]
    (click for bigly image)
    The wheels fit 3/4" OD axles. I cut 3/4" wide x 3/8" deep slots in two pieces of 2x4, fitted 3/4" steel rod, and secured the two 2x4s w/ screws + glue. The wheels are retained w/ hitch pins.

    Because my lawn is soft/spongy, I needed to use strips of scrap plywood to allow the tires to roll easily. When it was time to turn, I lifted and moved one end (using my automotive floor jack). When I was ready to connect the tower to the baseplate, I used the above again to position the tower. :)
     
    WB5THT likes this.
  8. KI7HSB

    KI7HSB Ham Member QRZ Page

    Nice looking solution... I may end up doing something like that myself to make it easier to work on and live with until everything is in place and I can stand the thing up where it is intended.

    If I'm determined to work on the thing in sections, an option might be to grind the stop tabs off the tops and replace them with a very safely designed bolt-on replacement tab after I'm ready to put it all together and into service.... That would allow the sections to slide apart out through the bottom. Not real keen on re-welding something like this, but I am an engineer after all, so I'm confident I could design something safe.
     
  9. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    The "stop blocks" on my tower prevent a section from slipping too far down into the next one, so they "nest" when they hit the stops; however those only prevent the sections from collapsing and would not prevent each section from being pulled out "vertically" until they're separated.

    Check everything again.

    I remember visiting Tri-Ex decades ago when I watched them assembling telescoping towers after they came back from hot-dip galvanizing and the sections were separate, the galvanize covered all welds, and they didn't do any welding post-galvanizing. I even asked one guy doing that "What prevents the sections from all slipping out this end?" (pointing to the "small" end of the tower) and he said, "The cables, and gravity." You'd have to remove the cabling and turn the tower upside down for that to happen.
     
  10. WZ7U

    WZ7U Ham Member QRZ Page

    I figured it would be out the top as well, after cabling removed. I bet that's the ticket.
     

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