[MHml] mast rake
Dan.Frenette at Sun.COM
Fri Nov 17 07:13:29 EST 2006
I've been quiet as I don't like to make an emotional remark.
First off many of the R33's are trailered. Things happen to masts going
up and down that you REALLY can't engineer out of the equation. We don't
know that this boat? in question was trailered or not.
Based on my experience with the R33s (disclaimer one of the dealers is a
friend) the boat is pretty well thought out, built with good materials,
from sources that would be hard to question their quality.
As far as arm chair engineering goes, I don't have time to run the
numbers. However the number get a bit high when you narrow the boat. The
loads on a 14' beam would be higher than say a 20' beam. As in a
difference of 6 so what about a 40% decrease in compression. I don't
recall the beam on a Mac 36 but this should be enough in the ball park
give you and idea this needs to be calc'd.
Light air work is where a lot of stuff breaks as the rig tends to flop
around. The F27 owners about 10 years ago really some scratching their
head when the said the main sheets broke in well drifting conditions.
This is because you can't crank the main in hard or the jib will go bead
sheet flat and you will just park the boat. Now add the odd power boat
wake locally that can be up to 4-6' (if you run the numbers a 2' wave
maybe more than enough) and you get max loading on in >1/2 knot of wind.
Now add any dimple in the lower aft third of the mast, or any bonding
issues on the spreader tubes to the mast (had one pull out once), or
diamond wire connects on the spreader not captive or just loss and you
get a gravity storm.
The materials Larry is starting with if the mast tube isn't damaged
should be the right stuff. The implementation needs to be done or
reviewed by a professional. Masts are hard to do right. Get any part
wrong and someone could have a tree fall on them. The decks don't give
very well so it's not a good thought.
Ira Heller wrote:
> I object to this kind of rumor mongering and hearsay. The report
> that a particular boat broke its mast is of little to no use as you
> give no follow-up details as to how it happened. I've sailed a
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