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Author: Patrick Lewis
Subject: Stability when climbing the mast
Info: (12168 views) Posted: Thursday 7-11-13 05:37:48 PM
I'm 195#, and haven't ever had a problem (and have spent way too much time at the masthead). As long as the people on deck are paying some sort of attention, I wouldn't worry too much. Cheers, Patrick

:: 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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