[TowerTalk] Question about lowering a Fold-Over tower

[Gary Schafer]

A friend of mine did this with a small (30') tower on field day. When the
tower got down low it pulled the Jeep that it was attached to and slid the
wheels.
The tower swung out off center and crashed down. There is tremendous force
on the cable when the tower is near the ground.

You also need side guys on the tower when raising/lowering like that.
The falling derrick is a must.

73
Gary  K4FMX

> -----Original Message-----
> From: towertalk-bounces at contesting.com [mailto:towertalk-
> bounces at contesting.com] On Behalf Of Wilson Lamb
> Sent: Thursday, February 02, 2012 10:49 AM
> To: towertalk-request at contesting.com
> Subject: [TowerTalk] Question about lowering a Fold-Over tower
> 
> 
> Dick,
> Please don't do this until you can get some onsite help.  You're looking
> for
> trouble!
> 
> As that tower gets near horizontal, the compression/buckling load from
> the
> cable will be LARGE, easily enough to pull out a brace, if that's where
> you
> hook on.  Who knows if your hinge hardware can take the load?  It might
> be
> enough to spin the tires of your car, if on grass.
> 
> Worse yet, if you get the least lateral displacement you will get the
> cable
> off to the side of the hinge/tower plane and you will then have the top
> of
> the tower trying to go sideways because of the cable pull being off
> axis!
> You can tear your hinge apart and wreck your beam in a heartbeat!
> 
> The falling derick advice is right on, BUT you have to be sure the base
> of
> the derick is wide enough to provide the lateral stability you need to
> prevent the off center situation above.  AND you have to secure the
> cable to
> the top of the derick so the derick can't slip on the cable and drop the
> tower as it gets low!  20' of Rohn 25, guyed to the sides, would make a
> good
> derick.
> 
> There may be other problems, but this should be enough to convince you
> to
> wait for some local guidance.
> 
> Good luck,
> Wilson
> W4BOH
> 
> 
> 
> 
> Hi Guys,
> I'm going to lower a 90' Heights aluminum fold over tower with  my car
> tomorrow evening.  I've done this before without destroying the  tower
> so
> hopefully I can have another successful lowering!
> 
> My question is what is the best height on the tower to  attach my Nylon
> Strap for lowering the  tower?
> 
> A few thoughts:
> 
> 1) The 90' tower folds over  at ground level and has a 36" wide base.
> 
> 2) In the past, I attached my nylon strap  around the tower at aprx. the
> 35' level and then attach a 1/4" steel cable to  the nylon strap and
> raise
> and
> lower the tower with my car.
> 
> 3) I keep the top of the  tower 13' off of the ground so there's room to
> attach my 24' boom  Yagi to the top of the tower.  Keeping the top of
> the
> tower 13' off of  the ground makes it easier to lower and raise the
> tower
> with a
> vehicle than if  the top of tower was on or near the ground.  That said,
> with the  top of the tower 13' off of the ground it's still quite touchy
> raising and  lower the tower as only as a small movement in the vehicle
> makes a
> big  change in the tower.
> 
> So I'm looking for the best strap height to lower  the tower and the
> best
> strap height for raising the tower.  After  using the 35' height
> before... I
> don't think that one height is the ideal height  for raising and
> lowering
> the tower.  Since it's easy to locate the nylon  strap anywhere on the
> tower
> I'm looking for the best height for lowering and  best height for
> raising.
> 
> All thoughts appreciated!
> 
> Thanks-
> 
> Dick- K9OM
> 
> 
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