I get long winded sometimes so bear with me, but if you want to know, we live on the edge of failure.
We use a form of LRFD where we apply overloads to our loads and we go all the way to yield. Our overload on the hurricane wind is 1.1 and the overload on the wire tension is 1.2 during a hurricane. We use the ASCE 7 wind map and design for a 50 year MRI storm. So for 98% of its life, the stresses in the poles and towers are under 15% of capacity. We use our own buckling formulas for single angles in compression based on testing many years ago. For cold parts of the country the NESC prescribes the overloads and ice accretion on the wires. These are much higher at 2.5 for wind, 1.65 for tension and 1.5 for weight.
When we design a new tangent lattice tower or pole we usually do a full scale test and usually test to destruction (not many bridge engineers can do that) to show proof of concept. We may fabricate the same tower 2000 times over its life so if we can save 500 to 1000 pounds per tower at $2 per pound, we feel it is worth it. The heavy angle towers and poles use a little more overload since not many test facilities have the capacity to pull one over.
It is usually not the wind that brings down a pole or tower, but wind borne debris that wraps around the structure or wire that increases the wind force dramatically.
Some call for all lines to be put underground but it is very expensive at the transmission voltages of 138 kV. We recently completed a 6 mile UG line that the State paid for that cost $10 million per mile which is 8 to 10 times as expensive as overhead lines. You have to dissipate a lot of heat into the ground when you go UG.
AFA living next to a large tower or pole, we use wide ROW where the fall distance would not hit any house outside the ROW. When they do fall it is not like a tree but the crumple down upon them selves.
I hope you guys enjoyed my dissertation, but only structural engineers that do lattice towers are crazy enough to use single angles in compression and we have some 12x12x1.25 angles welded up from plates to handle some very large leg loads.
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I have been called "A storehouse of worthless information" many times.