Correct - The RTS is actually a well designed system. One CAN replace the
main bearing as well as the other bearings - something that can not be done
on a XG tower without lifting the WHOLE tower - which is probably not
possible with all the antennas on it and would be an expensive proposition
if it were (A BIG crane). Now I know those that swear by it will say it
hasn't ever failed and won't ever fail .... but that is not great planning -
EVERYTHING can fail. I was told the same thing about the used system I
bought - the cam followers were almost all LOCKED up ... I was told "they're
good - just grab them with a big wrench and turn them a few times - they'll
break loose" ... I instead replaced all of them with new ones - an expense I
didn't expect to have to foot. Oh - and they would be very difficult to
change readily although I suppose one could drop that guy set and wrestle
with it. Installing them in the first place is a real treat. NOT well
thought out.
Gary
K9RX
-----Original Message-----
From: Jim Thomson
Sent: Sunday, July 16, 2017 11:02 AM
To: towertalk@contesting.com
Subject: [TowerTalk] Bearings for Axial Load
Date: Sat, 15 Jul 2017 19:42:29 -0700
From: Grant Saviers <grants2@pacbell.net>
To: towertalk@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.
<Grant KZ1W
## 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.
Jim VE7RF
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