Saturday, July 5, 2014

Could a Tanzer 16 Mast Float--Theoretically -- Maybe

Could a Tanzer 16 Mast Float--Theoretically -- Maybe -- Not Likely -- July 5, 2014.  Working on a different project and a different post about the hinged mast step yielded an unexpected conclusion--Maybe a Tanzer mast could float--I doubt it since so many Tanzers are sold without rudders and there are more than a few tails of turtles.

The inside of the mast is filled with polystyrene beads.  I assumed it was to keep the water out, not to make the mast float.

These beads are forty years old and down at he bottom of the mast so lots
of water must have worked its way down there.  The ones at the top
are much lighter in color.

But--here are the numbers.  The inside of the mast extrusion has an area of approximately 4 square inches. So the volume of the inside of the mast is 4 sq in x 24 ft x 12 in/ft which equals 1152 cubic inches.

Water weighs .03606 lb/ cu in x 1152 cu in = 41 pounds of water.  So if the mast were filled with water, the whole mast would weigh 31.4 pounds (weight of mast) + 41 pounds of water = approximately 72 pounds.

BUT--if you filled the mast with beads, it would support 1152 cubic inches x .3606 lbs/cu  41 pounds (10 more pounds than the weight of the mast)--so theoretically the flotation in mast might cause it to float--but it doesn't.  One would suppose that the weight of the two wet sails, the standing rigging, and even the weight of the boom would add enough mass to insure that given a few minutes in choppy water, the mast is going to point toward the bottom.

To calculate area, I just found the area of the rectangle and
deducted the triangles that were not inside the mast.  It's
very approximate, but good enough since we are just

The good news:  If you keep the beads in the mast, and act quickly you can usually right the boat.  The bad news:  If the mast fills with water there is almost no way you could get it back up--and, even if you could, with 72 pounds 24 feet above the boat it would be so unstable that almost anything would knock it back over.

The take away:  If you are dinking with mast, keep the beads inside -- which I am and which I will.

Today's Cliche:  Attitude is 90 percent of everything--but new sails help.

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