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[TowerTalk] Gin Pole and Rope Economy

 To: [TowerTalk] Gin Pole and Rope Economy w7ni@easystreet.com (Stan or Patricia Griffiths) Thu, 14 Jun 2001 13:50:23 -0700
 ```One thing that constantly surfaced during the discussion on using a block and tackle with a 3:1 mechanical advantage to reduce the load on the gin pole was the objection to having to use a LOT of expensive rope. Here is a technique to minimize that problem. Yes, its more work, but uses a LOT less rope. There is always a trade-off . . . Say you are raising a 200 pound mast up to the top of a 100 foot tower. If you are a believer and plan to use a 3:1 block and tackle at the top of your gin pole (which is sitting at about 110 feet above ground), you will need a continuous length of rope that will run 4 times up and down the tower from the top of the gin pole to the ground, or 440 feet of rope. This is a LOT of expensive rope . . . But wait! It only has to be one continuous piece if you expect all of it to fit through the pullys. That last piece that runs down the tower to the workers pulling the mast up never has to pass through the block and tackle pullys so it can have a knot in it at the top of the tower. This still means you need 440 feet of rope but it can be made of two pieces . . . one is 330 feet long and the other is 110 feet long tied to the first piece. Yes, 330 feet is still a very long and expensive piece of rope, but wait . . . there is a way to save even more rope! In this next scenerio, you lift the mast in two stages. Stage one gets the mast to the top of the tower. You can do this by rigging a single pulley on and near the top of the tower itself (not the gin pole). The tower is generally PLENTY strong enough to support the entire load with no benefit of the mechanical advantage of a block and tackle. This step requires a length of rope 200 feet long, and anyone contemplating a 100 foot tower should already own a strong rope of this length. Next, you temporailty tie off the mast near the top of the tower and prepare to hoist it the last 10 feet over the top and down inside the tower. This is the only time you need to use the gin pole to help lift this mast in place and therefore, the only time you really need the mechanical advantage of the block and tackle. Since you won't be using the gin pole and block and tackle to do a lift from the ground, you only need about 36 feet of rope to run 3 times through the pullys to do a 10 foot lift at the top of your tower. You still need to get the end of the rope to the ground 110 feet below so the rope needs to be about 146 feet long. We already decided you have to own a 200 foot piece anyway so you have all the rope you need to do this. But wait . . . there is more! This last 146 foot piece can really be two pieces tied together since the 110 foot piece going from the top of the gin pole to the pulling crew will never have to pass through the block and tackle pulleys. It can be made of a 110 foot piece with a 36 foot piece tied to it. So that's it . . . the only thing you need now are a couple of good blocks . . . one single and one double. I have found them at estate sales for as little as \$5 or \$10. New ones cost about 5 or 10 times that much but think of all the money you are saving on the rope you don't have to buy now! The above suggestions would have been pretty useless a couple of days ago when we were still arguing about whether it makes any sense at all the use a block and tackle for lifting heavy masts. Stan w7ni@easystreet.com List Sponsor: Are you thinking about installing a tower this summer? Call us for information on our fabulous Trylon Titan self-supporting towers - up to 96-feet for less than \$2000! at 888-833-3104 www.ChampionRadio.com ----- FAQ on WWW: http://www.contesting.com/FAQ/towertalk Submissions: towertalk@contesting.com Administrative requests: towertalk-REQUEST@contesting.com Problems: owner-towertalk@contesting.com ```
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