Have a look at
http://www.n6rk.com/falling_derrick_gme/falling_derrick_gme.html for a
lot of info on the falling derrick method.
We used this method on FD to erect 40 ft of Delhi tower with a TH3 on
top and a 2m/70cm gain vertical on top of that. Used a 20 ft wooden
extension ladder for the "derrick". Used 4 way guying so 3 guys of the
right length could be attached to the anchors. Once it's up, the 4th
guy is attached. One person pulled on the rope tied to the top of the
ladder and, to everyone's amazement, up she came. Takes quite a while
to rig, though.
Hope this helps
73 de Jim Smith VE7FO
Tom Hybiske wrote:
> > ----Original Message Follows----
> > From: wf3h@comcast.net
> > To: TowerTalk@contesting.com
> > Subject: [TowerTalk] Guying a tiltover tower
> > Date: Fri, 29 Apr 2005 19:34:10 +0000
> >
> > I'm looking at erecting 70' of Rohn 25 with a Pro 67B at the top. This
>will
> > have no thrust bearing, and the antenna will be <1 foot above the tower.
> >
> > I'd like to put up a tiltover, tilting from the base, rather than a
> > foldover. Towers I've seen that are tiltovers are usually guyed
>differently
> > than non-tiltovers. Any suggestions or references about guying?
> >
> > How about mechanisms for tilting? Anybody have good ideas on how to
>actually
> > tilt the tower?
> >
> > Thanks all
> >
> > Bob/WF3H
>
>
> Bob, you can do it but it isn't straight forward. The late, great Gerry
>Mathis W3GM used a "falling derrick" method to tilt over 100' of 25G with
>large arrays attached. I have a very bad slide that shows the derrick tower
>that normally rested on a winch bracket I could forward it to you, but it
>doesn't show very much detail. I've quoted a Towertalk message below for
>your reference. If you search "W3GM" in the towertalk archives, you'll find
>other messages concerning the use of this technique. I personally used it
>at his QTH on several occasions and can attest to the fact that it works
>well, and sure beats climbing a 100 footer in a March snow storm to fix a
>stuck rotor! I'd suggest you contact someone from the Frankford Radio Club
>as I understand there might be other members who currently employ this
>method, and may have plans.
>
> quoted from a message posted on 29 March 2004, by Jim Jarvis, N2EA:
>
>"Gerry Mathis, W3GM, used a slightly more formal version of
>this system with multiple 100' rohn 25 towers at his station.
>The towers were guyed 4 way instead of 3, and the "back" guyset
>was attached to a horizontal run of 25G which was 3 or 4 sections
>long.
>
>He fabricated a mating, hinged section for the tower base, such
>that the main tower and the derrick tower were tied together and
>the assembly tilted over.
>
>A dead man and winch was installed at the point where the derrick
>tower came to ground. Gerry drove this winch with a 1/2" electric
>drill. It took him about a half hour to raise or lower the tower,
>given the gearing, but it was amazing to watch a guy almost 80 years
>old singlehandedly repair his 40m beam by laying it over.
>
>There is a published design to keep the beams horizontal during layover,
>by the way.
>
>At least two members of the Frankford Radio Club use Gerry's scheme
>on their 100' towers today."
>
>73, Tom Hybiske K3GM
>
>
>
>
>>
>>
>>
>>
>
>_______________________________________________
>
>See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
>Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
>questions and ask for Sherman, W2FLA.
>
>_______________________________________________
>TowerTalk mailing list
>TowerTalk@contesting.com
>http://lists.contesting.com/mailman/listinfo/towertalk
>
>
>
>
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|