[TowerTalk] Bearings for Axial Load

[StellarCAT]

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 at contesting.com
Subject: [TowerTalk] Bearings for Axial Load

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.

<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