[TowerTalk] Taking down a tri-ex LM354

[Grant Saviers]

I made a new base (welding grade rebar of course) and put one (LM354 not 
HD) up last month.  A mid size Kubota (35hp) front bucket wouldn't lift 
it as I predicted so Western Crane was hired to raise it.  That was 
simple and $300 I think for the new owner.  btw the cables were replaced 
and the seized sheave bearings as well.  If you get into those fixes you 
might find some interesting issues.

My HDX589 is a bit more tower (2.5x weight) and for hoist uses a 7' mast 
of 2x6x0.25 rectangular tube with a 4:1 pulley system at the top and a 
2550 winch.  The forward braces are two 2x2x.25 sq tubes bolted to the 
holes above the pivot bolts and attached to the mast at 4' up.

If you are keeping the 354HD then you will need a new base and you can 
buy the lifting derrick at the same time or weld both up.  The flange 
and holes on the leg about 7' up opposite the pivots is the attach point 
for the erecting cable.   All the holes are in the existing base to 
attach such a derrick.

The HDX589 is a substantial bear to erect.  The force needed 8' up the 
tower to lift from horizontal is huge.  A little mechanics of solids and 
geometry and you can calculate it.  At the top of the tower the max load 
is 1/2 the weight of the tower plus antenna, cables, rotator weight when 
it is horizontal.   Consider that if you are thinking about supporting 
the tower partially elevated.  I've seen a tower bent with a support too 
close to the base and your average step ladder is going to break even 
near the LM354 top.

Be safe!  Hire a crane, only climb when the tower has all sections fully 
blocked, or best, with a decent size crane you can connect at the 
existing derrick lift point and not climb at all.  The base can handle 
the pivoting loads if in good shape.  Check the rebar carefully at the 
concrete surface.

Grant KZ1W


On 6/8/2014 4:43 PM, Gary Schafer wrote:
> I just bought an LM354HD tower that is still standing. Weight is close to
> 1000Lb and it stands about 20feet nested.
>
> Any ideas how to get it down safely without a crane? It does not have the
> tilt over option installed. it will hinge at the base.
>
> Thanks
> Gary K4FMX
>
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