Jun 22, 2015 - 02:02 PM
Guyed towers make up all tall towers over about 700' and can reach as tall as 2,000'. The tapered tower base sits on a pin and the guy wires reach out from each leg to anchor points in three directions. It is the tension of these wires pulling against each other that keeps the tower standing upright. ANSI recommends that guy towers be inspected every 3 years and that inspection includes taking and recording the tension measurements of all the guy wires and looking through a special transit to see if the tower is plumb, meaning straight. The standard is that the tower can be leaning in different directions 1 inch horizontally per 100 feet of vertical tower. An 800' tower can be leaning 8" in any direction at the top.
Guy wires are made up of multiple wires and strands that wrap around each other. Guy wire sizes are measured and referred to by the diameter of the wire. This diameter and type of material the guy wire is made from dictates how strong the guy wire is and how much tension can be placed on the wire. Guy towers are designed in a way that the guy wires can hold the tower and the antenna and line loading and not exceed 10% of the maximum breaking strength of the wire. 1/2" guy wire has a ultimate breaking strength of 26,600 lbs, a tower with 1/2" guy wires should have 2,660 lbs on each guy wire, if we were to take a measurement of the guy wire tensions.
Some guy wires have to be greased for maintenance and in places where winters are harsh guy wires may have "ice breakers" on them, to help alleviate the ice buildup on the wires. Tall towers have "snubbers" which are anti-vibration devices on the guy wires. Some guy wires have so much tension on them that we have to use a hoist at each tower guy anchor to pull the wires to their proper tension.