A suggestion:
A number of times we've resorted to using a long Aluminum extension
ladder(s) (cross wise with hooks U-bolted to the tower to keep the
ladder from slipping) on 50 and even 60' 25Gs in place of the 2 X 4.
The ladder can also be used as a support to hold the tower so every one
can take a break.
You can even use 2 ladders on a 60 footer.
If possible have a practice session so every one knows when to do what,
safely.
As far as the hooks on the tower, use a bit of ingenuity. They can be
real hooks, channel, or a welded bracket. Just keep safety in mind.
NOTE! If doing this with an Aluminum tower, build a bracket for the
ladder to push against and not the tower itself. A small pressure
point, as in the rung of a ladder can easily damage the tower legs. The
top ladder rung can be inclosed with split PVC conduit tapped together,
or a rubber sheet of 1/8th" thickness or more. You can resort to using a
longer sheet and winding multiple turns of 3 or more ans wrapping that
with tape to hold it in place. Just make sure everything fits, BEFORE
the actual lift, hence the practice session. If it goes well, it
practice can turn into the actual lift. Just go into it with the idea
that the tower does not have to go up this time.
"Walking" a tower up can present some safety issues, hence the reason
for the practice session, or "walk through".
In the long run you might find the falling derrick easier.
73 and good luck what ever route you take
Roger (K8RI)
On 3/9/2015 9:29 AM, Patrick Greenlee wrote:
Say what? If the tower were not tapered (lets look at a simple model)
and you picked up the top then you would support 1/2 the weight and
the ground via the hinges would be holding the other half of the
weight. The higher the top of the tower goes the greater the portion
of the weight is held by the ground/hinges until when vertical the
ground holds all the weight.
Buy a 16 ft 2x4 and either notch one end and apply duct tape to secure
it to about 16 ft above the tower base or otherwise secure it with
wire or...
Then as you lift the tower the 2x4 can take the load while you rest,
change hands, take a break or ... Once the tower is lifted so high the
2x4 is not securing the tower very well grab hold of the 2x4 and use
it to push on the tower. The increased leverage pushing at the 16 ft
level rather than at your head height or so will make a considerably
easier time of it.
Archimedes said something like given a lever long enough and a place
to stand he could bend the lever (move the Earth) or some such.
Patrick NJ5G
On 3/8/2015 11:45 PM, Richard (Rick) Karlquist wrote:
On 3/8/2015 5:36 PM, Hans Hammarquist via TowerTalk wrote:
If you don't put to much heavy stuff on the tower before you walk it
up it should be OK. Just for your comparison, I have an 85 feet
aluminum tower and the total weight of the tower, empty is 300 lb.
It's tapered so the heavier section are at the bottom. No, I didn't
walk this tower up but I easily carried around the top 40 feet
during the assembly of the tower and could, probably have raised the
by myself as a 40 foot tower, had I done that.
Hans - N2JFS
I made some calculations and determined that the
force you have to apply to a 40 foot tower of
uniform cross section with nothing on top works
out to 1.7 times the weight of the tower. And
you have to be able to apply this force using
one hand at a time while you "walk". It all
depends on the weight of the tower and the
strength of the walker. Can you hold an 85
pound barbell over head and pass it back and
forth between your hands? Then you can walk
up a 40 foot tower weighing 50 pounds.
Rick N6RK
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73
Roger (K8RI)
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