On 7/30/2012 5:53 PM, John Harper wrote:
> Please pardon the dumb question...I'm on new turf:
>
> In a couple weeks, a crane will be coming to raise 30 feet of Rohn 25 tower
> (in one piece) onto the existing 20 feet already in the ground. How does the
> crane normally release from the section to which it's attached? That point
> will now be 50 feet high and I know taller towers are raised this way.
>
> Is the tower attached to the crane by the hook, which falls away once there
> is no longer a load on it or is there some other way (short of climbing up
> there to untie)?
>
Normally the tower is hung on the cable by a "hook with a safety catch"
so it can't fall off.
Secure the guys to the top section, *before* they raise it into
position. Some one has to be at the top of the 20 foot section to guide
the tower into position and install the bolts. They guy lines need to
be attached to the guy anchors before you unhook the crane.
I'm assuming this will only have one tier of guys and they will be
attached maybe 3 to 5 feet below the top, of the top section.
I would attach temporary guys to the bottom 20 feet, not because it'd
normally need them, but because things can go wrong and you don't want
the crane knocking 20 feet of tower out from under you.
The tower needs to be straight and guyed before you go to or near the
top of a 50 foot 25 G.
If you aren't sure about the way things are going have some one on site
to help. Play it safe!
I say this in all seriousness: Finding yourself on top of a 50 foot wet
noodle is no time to discover you don't like climbing.
73
And good luck.
Roger (K8RI)
> Tnx/73,
>
> John AE5X
> The tower in progress:
> http://www.ae5x.com/blog/tower-installation/
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|