[TowerTalk] Bearings for Axial Load
jim.thom at telus.net
Sun Jul 16 11:02:21 EDT 2017
Date: Sat, 15 Jul 2017 19:42:29 -0700
From: Grant Saviers <grants2 at pacbell.net>
To: towertalk at contesting.com
Subject: Re: [TowerTalk] Bearings for Axial Load
< One issue I've been told about with rotating towers but never
<done or seen done is how to replace the bottom bearing without taking
<the tower down.
## On the original RTS setups, they used 3 huge, and long, threaded rods, every
120 degs, between the mating plates, not quite into each corner. Then nuts and washers
on both sides of both plates for each of the 3 threaded rods. These threaded rods were a
temporary setup..... typ used when the rotor was at the 40 to 50 ft level. IE: Bottom 40-50
feet did not rotate. But same deal was used with rotor below 10 ft level. The threaded rod assy
held the 2 sections of tower together..and dead straight..and upper sections would also not rotate.
## Once guys were all installed... or at least the lower guy wires on the upper sections, then the 3 x temp
threaded rods could be removed.
## For replacement of that huge bearing at the bottom, I think the procedure was to re-install the 3 x rods, all guys loosened up a bit..and I think
a hydrualic jack used to lift the upper sections a tiny bit...then rod assys tqed down. Then bearing removed, and
replaced, and rev process done. The bearings used on the rings were designed to be replaced..after the fact.
## On broadcast station base insulators, they use a hydrualic jack to elevate the tower enough to replace the insulator.
Saw in a really old national geographic magazine, where a 1200 ft tall tower, used as part of the oem dew line set up,
used 3 insulators at the base. 1 was cracked badly. They actually jacked up the entire 1200 ft tower...and replaced all
3 insulators with one big one. It was quite the engineering feat at the time....in the late 50s.
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