Just thought I would share this free standing crank up tower experience
with TT's. If anyone else has had a similar experience, or expertise to
offer, I would like to hear from you.
I have a UST HDX-555 with a MD-75 motor drive. In attempting to lower the
tower during windy conditions (~ 45 MPH & no positive pull down, and
physically standing about 12 feet from the tower to observe the cable
tension), I stopped it at the 40 foot level and decided to go back up a
couple of inches (cable tension visually looked normal) just to make sure
everything was tight. At this point the 1 HP motor could not drive up or
down! (motor stalled - no slip in either the drive or load pully) After a
visual inspection from the ground of the cables, I removed power plug,
and was able to lower the tower about an inch by simply pulling on the
drive belt (something changed!). To my horror, additional pulling of the
drive belt caused to shaft input to turn, but NOT the cable take up drum.
I called UST, and their reply was "We haven't had that happen in 20 years
of being in business - something had to be binding, and you likely have a
lot of small pieces in the gearbox". Anyway, I suspect something did
bind, I'm guessing the side forces, from the wind, coupled with a fairly
heavy mast & antenna load may have been the culprit. What is disturbing
here is that the fairly massive "Hub City - Worm Gear Reducer" assembly
failed. (fortunately the gear directly connected to the drum was held in
place). The Gear Reducer and the cable are the key elements that keep the
tower from crashing down. I suspect I will need to get some professionals
with the proper equipment to get the upper sections lowered. For the time
being, a 4x4 jammed under the second section should keep it from dropping
if something gives in the gearbox.
Lesson learned: Only go down in heavy winds.
Frank W9JCC
________________________________________________________________
GET INTERNET ACCESS FROM JUNO!
Juno offers FREE or PREMIUM Internet access for less!
Join Juno today! For your FREE software, visit:
http://dl.www.juno.com/get/web/.
List Sponsored by AN Wireless: AN Wireless handles Rohn tower systems,
Trylon Titan towers, coax, hardline and more. Also check out our self
supporting towers up to 100 feet for under $1500!! http://www.anwireless.com
-----
FAQ on WWW: http://www.contesting.com/FAQ/towertalk
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
|