On 8/15/2010 9:57 PM, Ed Richardson wrote:
> Planning some tower work that may involve lifting a loaded mast a few
> inches. Does the group have a preferred model or models for this type of
> device? My tummy tells me the 4 or 5 ton models by Neiko found
> frequently on Ebay would be too risky for this type of work.
I simply use a 2 ton come along with a SS 1/4" cable. The pulley is
mounted at the bottom of the mast similar to what I believe Ron
mentioned. The cable goes from the comealong, down through the pulley
mounted on a cap that fits over the end of the mast. The cable is
"captive" within the pulley arrangement so it can not jump off. This
also gives a straight pull up on the mast and with the climber operating
the come along they have precise control of the positioning without
having to depend on communications to a ground crew. Remember when
using a ground crew on something like this they need to be well trained
to respond instantly and properly to communications from above.
NOTE, blocks are placed through the tower under the mast and pulley to
prevent it from dropping should anything break. OTOH the maximum load
the come along will be lifting is 1 130# 40M3, 1 40# C3i, possibly one
14# 17L 2-meter yagi, 2 100# 2" DOM masts, plus one 20# coupling for a
total of 404#...IF nothing binds which is another reason for the manual
operation of the lifting operation at this point. The load is only 10%
of maximum for the comealong.
We will be using a capstan with the cable that goes through a pulley at
the bottom of the tower (snatch block), up through the gin pile and back
down to the mast sections. Going up is not so much of a problem except
when passing guys, accessories, and positioning at the top when getting
ready to lower the mast through the thrust bearings. These are sleeve
bearings that provide side support only. I may use over size sleeves
with Delrin inserts.
Final positioning once the mast sections are in place and properly
coupled will be done with the come along.
BTW the mast sections are sealed with about 3/16" to 1/4" thick sections
welded over the ends and then painted. A small hole will be drilled and
threaded through the top of the 1/4" wall DOM . About a quarter can of
LPS2 will be inserted and then the hole sealed and the set screw painted
over.before installation. Using LPS2 any leakage will be readily
The 7L C3i (29' plus boom) will be installed near the top of the mast.
Then the mast will be raised 15' and the 130# M^2 40M3-125 will be
trammed to the top of the tower and fastened to the mast. The rotator
will be installed inside the tower and the mast lowered to just above
the rotator and then clamped. The pulley and cap will be removed from
the bottom of the mast and the rotator raised into position.
The final position should be with the 40M3-125 one foot above the top of
the tower and the 7L C3i 15' above the 40M3, or rephrasing, the 40M3
should end up at 100' and the 7L C3i at 115'.
> Looking for something with double ratchet, at least two hooks and with a
> cable at least 3.4m (10')
Mine came with a 20 SS cable and second pulley.
Do not skimp on quality.
> long would seem minimum specs. What do
> thetower experts say and use?
I'm not an expert but the above is what I've used and will be using this
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