[TowerTalk] Crankup Tower Comparison

[dan hearn]

I am preparing to buy a 85-100 ft crankup tower. I have owned a UST TX
472 job for about 15 years with no problems. I do not use a winch system
for lifting but instead use a tractor and a floor sheave so have no
experience with the UST winch systems.
  I am considering both the UST and TRIEX towers and would like to
solicit any opinions on the two . There are some significant differences
that I see in the two brands:
  1. The UST uses welded angle guides where one section slides inside
the other. TRIEX uses pulleys at the contact points and I understand
they are plastic. My experience with the UST is that I had to do a bit
of hammer work on the angle guides to get free non sticking sliding
action but it works fine since. 
  Do the plastic pulleys stand up in sunlight over many years? 
  2. The TRIEX is advertised as being built of mechanical tubing which
has higher rated strength than pipe. I believe the UST is made of pipe.
On the other hand, the outside dimensions of the UST sections is
slightly greater than the corresponding TRIEX sections. 
  3. The wind load ratings of the TRIEX towers are higher than the
comparable UST.
  4. The UST uses a single lift cable to the winch with a multiple
pulley system for mechanical advantage and less cable stress. They use
single pass cables on the remaining sections. The TRIEX is advertised as
having a 3 cable lift system which is safer. I assume this is only on
the winch cable and not on the other sections. I am curious to know more
about that. 
  I believe that many of us put severe stress on the cable between the
2nd and 3rd sections from the bottom. This cable carries the weight of
the 3rd and all sections above plus the mast and all antennas and
rotator. On my tower this is a single pass cable. I am curious to know
if the heavier duty towers use separate cables to the winch or multipass
mechanical advantage on other than the bottom section. 
  I would appreciate any input regarding the design and experience with
these towers. 

73, Dan, N5AR

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