Good question Brian. Maybe you should ask the group.
Possibly the "falling derrick" technique?
73, Tom N4KG
On Sat, 05 May 2001 20:12:46 +0000 alsopb <alsopb@gloryroad.net>
writes:
> Just for curiosity, how in the old days of sailing ships did they get
> those 100' + masts of solid wood with two foot diameters vertical--
> especially the first one? I suppose it is easy in a shipyard.
> However, consider this:
>
> I saw a recent documentary where they still use sailing ships in
> parts
> of the Pacific near Indonesia. On one such trip, the main mast
> failed. The captain went ashore somewhere, bought a tree, had it
> shaped into a suitable mast and re-installed it. I don't believe he
> had another tall mast on the ship.
>
> How did he do it? They didn't say. Apparently, this is something
> which isn't too unusual, given that the captain wasn't any kind of
> mechanical wiz.
>
> 73 de Brian/K3KO
>
> n4kg@juno.com wrote:
> >
> > Picture this:
> >
> > You have 90 ft of R25 assembled and anchored at the base.
> > You lift the top 5 ft. Imagine a horizontal "rope" pulling on the
> top
> > towards the base. The tower weighs 300 to 400 lbs depending
> > on the weight of the lights, wires, guys etc. To hold the tower
> > 5 ft up will require a rope tension of ( 90 / 5 ) X 200 lbs = 3600
> lbs.
> > The BASE must also be able to withstand this *horizontal* force,
> > or more.
> >
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