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Author: Steve K
Subject: Stability when climbing the mast
Info: (3553 views) Posted: Thursday 7-11-13 09:10:31 AM
I find thisI an interesting subject. I go up the mast when I can't get the bowman to go up. He weighs 150, I weigh 170. I watched a Santana 20 tip over to put the spreaders in the water with no ill effects other then bruises on the mast climber. I've been at the upper spreaders on my boat tied to the pier when crew on deck moved and it scared hell out of me but the boat straitened up when crew stopped moving. If I have a choice I go up when the boat is on the trailer, wheels chocked, jack down on back of trailer. Always thought that was stable, the boat couldn't rock around. But this thread makes me wonder. What did the rigger tie the halyards off too?

:: 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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