Hello folks,
I have a quick question. I have a 25ft tall(nested) 300lb Aluma tower
to be raised.
The aluma is going to be bracketed at the 13ft level at the floor
joist of a 2 level
home.
While the concrete base was poured, i did install 3 additional 1/2"
anchor bolts
to install a raising fixture.
My choice to raise it are as follows.
a) Install a pulley at the bracket( 13ft from the ground level) and then install
a fulton hand winch a couple feet from the ground on the concrete pad
using the 1/2" anchor bolts to hold a fixture that attaches to the hand
winch to offset it from the base such that it has space for the handle of
the winch to crank.
My question is, what height should i tie the stainless steel cable to the
tower as it passes through the pulled at the 13ft level to winch this up?
My guess is 13ft of the tower from the base. But additional lift will be
possible if i can attach the cable to say the 20ft level of the tower or so.
b) Fabricate a tower raising fixture and attach it to the additional anchor
bolts i have in concrete. What i have in mind is to have something like 10ft
or 13ft tall say 1/4" thick steel pipe based fixture with a pulley at the top.
The fulton winch will be installed on the side of this steel tube.
I know the EZway raising fixture is an option, but i don't have the space to
excavate and set this in the ground due to the location ( i have say 2ft to 3ft
between the side of the house and the concrete base. I have an irrigation
plumbing pass inbetween this spot.).
My thoughts on the options are
a) The load will be shifted to the pulley installed at the bracket.
Can this failover
time? Don't know. I will need to think of a backup safety mechanism in case
something goes wrong with the pulley.
The load on the winch at the tower base and the anchor bolts will not
be substantial,
even though i am sure that the anchor bolts will be able to take much more.
b) This is a self contained mechanism. No failure points due to the pulley or
the winch. The only flip side is the load on the anchor bolts due to
the fixture.
The anchor bolts are 18" bolts that were set in such a way that it does not
touch the rebar, but had the anchors right under the rebar. So
should be good to
hold the load.
Oh i am using 3/16" inch steel cable that has a normal working
strength of 850lbs
for the fulton winch.
what are your suggestions. please let me know.
Thanks
John
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