In a message dated 7/14/2009 12:02:04 P.M. Pacific Daylight Time,
towertalk-request@contesting.com writes:
> The now defunct Wilson WT61 foot tower comes with a brochure saying it
can be strengthened to 20sqft wind load in a 50 mph wind by guying.
They show a single bearing being placed on the 3rd, top section with 4
guy cables. In discussions with hams who had guide crank up towers
collapse, there seems to be a difference of opinion over whether crank
up towers can or should be guyed. The argument is that when the wind
blows, the guys transfer the pressure down the tower. If the crank up
cable is supporting the tower, this can place stress on the tower and
down she comes! The Wilson has a single pin on a spring (mine gone)
where a small role may be pulled to place a non-slip pin into the top
of the first of three sections. A friend said this might take stress
off the cable that cranks and holds the tower, permitting guying. I
am interested in experience and opinions.
Around here I recommend following the LXC Prime Directive to "DO what
the manufacturer says." Pretty simple.
This is assuming that the existing cables and tower are in decent
shape of course. My caution would be to just barely tension the guys. You
don't
want to add to the compressive force on the existing haul cables. You'd be
using the guys more like a tether, just something to contain the movement
of the tower in the wind. This is a free-standing tower so the lower,
unguyed rating allows a small load without guying it.
Don't forget that the guys also take some of the downward force - it's
not all going on the tower haul cables.
And yes, crank-up towers can collapse. Just go easy on everything,
over-engineer it somewhat if you can and you should be fine.
Cheers & GL,
Steve K7LXC
TOWER TECH
**************Can love help you live longer? Find out now.
(http://personals.aol.com/articles/2009/02/18/longer-lives-through-relationships/?ncid=emlweu
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