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Author: Ralph Deeds
Subject: Stability when climbing the mast
Info: (11258 views) Posted: Thursday 7-11-13 12:48:33 PM
We usually send somebody up using the club's gin pole or somebody who is light with an extra halyard.

:: Thanks for the reply Bryan.
::
:: So you are saying that even with the boat on the
:: trailer, the rigger ran the halyards off to the sides
:: and tied them off to things? That seems extreme...I
:: would not have given it a second thought on the trailer,
:: but we can presume he knows what can happen.
::
:: I've been up the mast on many many boats and this was
:: the first time I've felt one start to go over - could
:: have been luck to date though.
::
:: Would love to hear any other experiences.
::
:: :: not sure if i did it right but i recently calculated
:: :: that my 180 lbs at the top of the mast would flip the
:: :: boat at the dock if the angle of heal exceeded... what
:: :: was it... 15 degrees?
:: ::
:: :: a rigger that i had re-run a halyard recently requested
:: :: the boat be on the trailer and even on dry land he took
:: :: every available halyard and used them to brace the mast.
:: :: he mentioned that he does the same if the boat is in the
:: :: water too but its more complicated.
:: ::
:: :: :: Just some quick math would say your 160 pounds is
:: :: :: offsetting the keels lever arm somewhere around 20 feet
:: :: :: off the water. Above that you're relying on the form
:: :: :: stability of the hull, so 'yes', all the way up the rig
:: :: :: should get real squirrelly! That presumes the center of
:: :: :: the 1100 pound ballast is about 3 feet under water (3300
:: :: :: ft lb of potential leverage). I know it's a LOT more
:: :: :: complex than a seesaw, but at the top of the rig your
:: :: :: lever for that 160 pounds is probably around 28 feet
:: :: :: above the water (over 4400 pounds).
:: :: ::
:: :: :: :: I went up the Express 27 mast not long ago and had a
:: :: :: :: somewhat scary experience.
:: :: :: ::
:: :: :: :: I weigh 160, and at the time there was a 200 lbs guy on
:: :: :: :: deck with the boat tied to the dock. I was at the top of
:: :: :: :: the mast doing some work and the guy on deck stepped to
:: :: :: :: the rail to do something. The boat started heeling
:: :: :: :: pretty extremely and truly felt like it was going to to
:: :: :: :: roll all the way over until guy on deck jumped to the
:: :: :: :: other rail to stabilize the boat.
:: :: :: ::
:: :: :: :: Would the boat really roll over like it felt it might?
:: :: :: :: Any experience with sending people up the mast on this
:: :: :: :: boat and how much weight is too much?
:: :: :: ::
:: :: :: :: We plan to go up the mast fairly frequently with the new
:: :: :: :: offshore rules for mounting and removing the masthead
:: :: :: :: VHF when doing offshore races, not to mention if we ever
:: :: :: :: had a problem and needed to ascend the mast while on the
:: :: :: :: water.
:: :: :: ::
:: :: :: :: I'm wondering what is safe?
:: :: :: ::

:: :: :: :: -dan
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