[TowerTalk] Crank up tower comparison

First Call Communications firstcall@cyburban.com
Thu, 16 Mar 2000 14:00:12 -0500

We have elected to answer Dan, N5AR's e-mail to Towertalk directly  so 
any interested parties can review the response.

In attempting to answer the questions for Dan we thought it would be 
advantageous if we forwarded his questions directly to Tri-Ex and
have management respond especially since a couple of areas touched 
on were quite important and perhaps misunderstood.

The response from Tri-Ex came in the form of a fax 
from Robert Vargas who has been for 30 years a most important member
of the manufacturing team working his way up to the title of Executive
Vice President of production.  Here is the response word for word from
Robert Vargas.

	My name is Robert Vargas, and I have been in the tower business 
	for over 30 years.  More specifically, I have manufactured the 
	Tri-Ex Towers during this period.  If I may, I would like to 
	clarify the design of the Tri-Ex Tower.

	1.  The Tri-Ex slide design is a very unique design to enable
	the sections to telescope with low friction.  The slides are
	NOT made of plastic; rather the tube is formed on each end with
	a special die.  On the larger outer sections however Tri-Ex uses
	aluminum rollers for ease of operation so the sections will have 
	no difficulty sliding.

	2.  Regarding the tubing used in the fabrication of the Tri-Ex
	Tower, tubing is a high grade mechanical tube that is not 
	available from normal tubing stock, further it is required to
	purchase mill runs in order to maintain the needed strength
	and maintain Tri-Ex standards.  The use of these materials 
	enable the Tri-Ex Towers to remain light in weight and yet have 
	a high wind load rating.

	3.  Regarding the questions on the Tri-Ex lift cables.  Tri-Ex
	uses a single lift cable to the winch with a multiple pulley
	system for mechanical advantage and less cable stress on the 
	main raising cable.  In addition, on all remaining sections a
	cable system is used on all three faces of tower to lift the
	tower evenly.

	Robert Vargas

We hope the above answers the questions on the operation of the Tri-Ex 
towers.  Since January, 2000 there has been a whole new of look of the
Tri-Ex telescoping towers. A lot was done and we invite everybody to 
look at the new web site <<www.firstcallcom.net>> as it is loaded with

We welcome your inquires.

Sales and Marketing Department
First Call Communications, Inc.
Fax:  914-357-6243
<<<<I am preparing to buy a 85-100 ft crankup tower. I have owned a UST
472 job for about 15 years with no problems. I do not use a winch system
for lifting but instead use a tractor and a floor sheave so have no
experience with the UST winch systems.
  I am considering both the UST and TRIEX towers and would like to
solicit any opinions on the two . There are some significant differences
that I see in the two brands:
  1. The UST uses welded angle guides where one section slides inside
the other. TRIEX uses pulleys at the contact points and I understand
they are plastic. My experience with the UST is that I had to do a bit
of hammer work on the angle guides to get free non sticking sliding
action but it works fine since. 
  Do the plastic pulleys stand up in sunlight over many years? 
  2. The TRIEX is advertised as being built of mechanical tubing which
has higher rated strength than pipe. I believe the UST is made of pipe.
On the other hand, the outside dimensions of the UST sections is
slightly greater than the corresponding TRIEX sections. 
  3. The wind load ratings of the TRIEX towers are higher than the
comparable UST.
  4. The UST uses a single lift cable to the winch with a multiple
pulley system for mechanical advantage and less cable stress. They use
single pass cables on the remaining sections. The TRIEX is advertised as
having a 3 cable lift system which is safer. I assume this is only on
the winch cable and not on the other sections. I am curious to know more
about that. 
  I believe that many of us put severe stress on the cable between the
2nd and 3rd sections from the bottom. This cable carries the weight of
the 3rd and all sections above plus the mast and all antennas and
rotator. On my tower this is a single pass cable. I am curious to know
if the heavier duty towers use separate cables to the winch or multipass
mechanical advantage on other than the bottom section. 
  I would appreciate any input regarding the design and experience with
these towers. 

73, Dan, N5AR>>>>

FAQ on WWW:               http://www.contesting.com/towertalkfaq.html
Submissions:              towertalk@contesting.com
Administrative requests:  towertalk-REQUEST@contesting.com
Problems:                 owner-towertalk@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm