[TowerTalk] Crank-up tower limit

[Doug Rehman]

The LM-354HDSP has been built since at least the early 1990's. Throughout
its life, it has had several redesigns/material changes that have resulted
in it going from 16 square feet at 60 MPH with a maximum dead load of 350
pounds (4/1993 Manual) to 52 square feet at 85 MPH with a maximum dead load
of 550 pounds (current website).

Even on an original model, 160 pounds would be a light load (about 46% of
the maximum).

Your proposed load is way under the capabilities of the LM-354HDSP. (Look me
up on QRZ to see what I have mine loaded with.)

Doug
K4AC

> -----Original Message-----
> From: towertalk-bounces at contesting.com [mailto:towertalk-
> bounces at contesting.com] On Behalf Of JP Lyet
> Sent: Monday, June 08, 2009 5:20 AM
> To: towertalk at contesting.com
> Subject: [TowerTalk] Crank-up tower limit
> 
> Had a Tri-Ex LM-354-HDSP cable failure 2 years ago.  Corrosion mostly,
> but actual cause is not known.  Otherwise flawless service for 10
> years.  In retrospect, suspect the antenna load may have been a
> contributing factor as between the 6 band yagi, T2X rotor  and mast,
> the total load was ~200#, or 80% of max load rating for tower!
> Tower was totalled and recently replaced with identical unit.  Beam
> refirbed to like new, but reluctant to use due to weight concerns.
> Anyone else in the group pushing a crank-up tower to ~ 80% of dead
> load limit on a regular basis?  Any other pearls or advice ?  Suspect
> my beam would be better served on a fixed tower installation and new
> tower with a lighter unit.
> (that being the case, anyone interested in a M-67B-3 can contact me
> off-line for specifics)
> Tnx, 73
> Paul /W3PL in Pa.
> 
> 
> 
> JPL
> via 3G