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## RE: [TowerTalk] Rohn Torque Bar confusion

 To: "TowerTalk" RE: [TowerTalk] Rohn Torque Bar confusion "Keith Dutson" keith@dutson.net Tue, 3 Aug 2004 16:59:42 -0500
 ```>but the farther away the attachment point is from the center of rotation the bigger the angle on the guy wire so the higher the resistance to the twist. Here is some food for thought. Take it to the extreme where the torque arm is lengthened and rigidly attached to both the tower and guy anchor point. Twisting the tower will result in bending the torque arm. Now, reduce the length of the torque arm to one inch less than the distance from the tower and install a one inch guy wire. Please don't laugh. I know hardware alone would not allow such a condition, but this is just for visualization of force. In this case the tower could twist a fraction without bending the arm. Or could it? Keep moving in to longer wire, shorter arm. In each case the resistance to twisting is placed on rigidity/strength of the torque arm and tension/strength of the guy wire. IMO, if you compare the above to a six point torque arm system, well, there really is no comparison. Keith -----Original Message----- From: towertalk-bounces@contesting.com [mailto:towertalk-bounces@contesting.com] On Behalf Of David Robbins K1TTT Sent: Tuesday, August 03, 2004 2:51 PM To: kr7x@comcast.net; 'Tower (K8RI)'; TowerTalk@contesting.com Subject: RE: [TowerTalk] Rohn Torque Bar confusion > When you translate the plane triangle section in rotation in its plane, > twist or torque load, initally the guys cannot resist the lateral > displacement as the guy's line of action is perpendicular to theaction > direction of the load. As the triangular section twists additionally then > there is created an angle between the line of force and the guy line of > action which can develop a vector resistance to the movement of the > triangular section. This value of resistance is a function of the sine of > the angle created. It wil start at 0 degrees at rest, sine of 0 degrees > is 0. > > This explains why the torsional resistance of the standard guying scheme > is so low and why if significant torsional forces are present in a tower > they twist. > > In this case the farther away from the center the guy attachment point is > really doesn't help with the torsional strength the angle between the guy > and the line of force of the torque is what matters. > but the farther away the attachment point is from the center of rotation the bigger the angle on the guy wire so the higher the resistance to the twist. Granted at 0 there is no force so it won't help with very small movements but adding rigidly clamped arms that approximately double the radius of rotation should increase the resistance proportionally. Also increasing the radius to where the reaction force is applied increases the length of the arm applying the force also increasing the reaction torque applied by the guy wires. David Robbins K1TTT e-mail: mailto:k1ttt@arrl.net web: http://www.k1ttt.net AR-Cluster node: 145.69MHz or telnet://dxc.k1ttt.net _______________________________________________ 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 ```
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