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Subject: TWL: Re: Boom lifting capacity
From: Peggy Carr (chesapklady@XXX.XXX)
Date: Tue Nov 05 2002 - 22:34:23 EST
>Most stock trawlers would be pressed to routinely take a 500 load safely.
>Not only is there the actual mast and boom--how are they made? How are the
>fittings attatched?--is there a cringle iron at the top of the mast, is the
>block thru bolted? What is the capacity of the gooseneck? Do you have
>adequate tackle to swing the load in and out? What shape are the spreaders
>in--are their properly positioned? One issue often forgotten is the mast
>compression load--this is straight down, and most trawler decks are not
>reinforced to take a load of 500 lbs or more. Reel winches (as used in
>sailboats) are nortorious for problems with the brake--with a history of
>broken arms, hands and boats.
Bob Austin's points here are well taken. In spite of having confidence in
many facets of our mast and boom construction, I have little or none in the
ability of the deck directly below the mast to receive the load. Seems to me
that the support of the mast should go all the way through, as do well built
sampson posts, in order to be strong enough to lift a heavy load.
The ability of any system to support a heavy load (in any sense of the word)
is only as strong as its weakest member.
Peggy Carr Bjarno
"Aqua Vitae"
1986 Albin 43'
Kent Narrows, MD
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