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## [Towertalk] mast disaster avoidance

 To: [Towertalk] mast disaster avoidance ve7hcb@rac.ca (Chris BONDE) Thu, 11 Jul 2002 15:20:15 -0700
 ```It has been awhile since I have done any mechanical stuff with pulleys. I think that you are on the right road but not all the way. If you are lifting a 100lb weight with one pulley at the top, you need 100+ lbs on the other side to lift it. I would then say that there is 200+lbs of weight on the pulley. If you are lifting a 100lb weight with 2 pulleys at the top and one on the load, then you have a mechanical advantage and need only 1/3 of 100+ lbs to lift the weight (I think that that is correct, but it is a lot less) Therefore, the total weight on the pulley is 100lbs plus the reduced amount hence less. I think that this is correct. Chris opr VE7HCB At 02:00 PM 2002-07-11 -0400, jljarvis wrote: >Mike... > >If you had a ginpole with a 2 wheel block on top (never seen >one, myself. Do they exist?), you would reduce the load on each >run of line, proportional to the number of lines. > >But the load on the axle is still the sum of the line-loads. >i.e., unchanged. > >The compressive load on the ginpole itself is thus still the >same, and the out-of-column bending loads are the same. > > >Jim/N2EA > > >-0- >From: "Mike Gilmer" To: >Date: Thu, 11 Jul 2002 12:16:03 -0300 >Subject: [Towertalk] Re: mast disaster avoidance > >I agree with most of N2EA's post except: > > > Solutions using added pulleys still leave the same load on > > the ginpole material itself > >This is not true. As has been oft-discussed on this reflector in the >past (and still misunderstood), judicious use of "added pulleys" can >reduce the total load on the ginpole. > >Mike N2MG > > > > >_______________________________________________ >Self Supporting Towers, Wireless Weather Stations, see web site: >http://www.mscomputer.com >Call 888-333-9041 to place your order, mention you saw this ad and take an >additional 5 percent off >any weather station price. >_______________________________________________ >Towertalk mailing list >Towertalk@contesting.com >http://lists.contesting.com/mailman/listinfo/towertalk ```
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