What Steve suggests is doubly true for Tri-ex towers like the LM-470 as even
when they are cranked all the way down the two top section are never truly
down on stops, they are by design still hanging on the cables so that the
Rotator can be accessed.
Mike, K6BR
-----Original Message-----
In a message dated 12/31/2010 6:55:18 A.M. Pacific Standard Time,
towertalk-request@contesting.com writes:
> What are you standing on when you perform this process? Are you on a
ladder, a man lift, or standing on the tower sections?
I'm standing on the tower.
> I have never found that 2x4s or steel pipes truly block a crank up
tower.
Sure you can jam 2x4s through the tower sections, and/or pipe section
through the telescoping sections, but it is clear that if the lift cable
sheared, the tower sections would drop significant amounts (enough to shear
off toes or fingers) before the blocks kick in.
What I do is to put the pipe or wood as close as I can to the bottom of
each section and then lower the tower until the sections are either resting
on or very close (within a couple of inches) to the wood or pipe. Even if
there's a catastrophic cable failure, the section is either not going to
move
or only move a couple of inches - hardly enough compression or movement to
break anything. That way there is minimal risk. Another thing you can use
is leg sized U-bolts bolted right under the section bottoms.
Of course climbing a crank-up - or any tower for that matter - is
potentially hazardous. The crank-up accidents that I've heard of were
fortunately
not fatal and happened on older towers without positive pull-down; a
section
would hang up when being lowered and it came unstuck and headed south when
it was being climbed. If in doubt, double up on the wood or pipe or
whatever you use to increase your confidence and safety factor.
Cheers & Happy New Year to all!
Steve K7LXC
TOWER TECH
and
_www.championradio.com_ (http://www.championradio.com)
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