Re: my schooner
Your comments are very helpful. Gary Webb from bearspaceindustries who designed Emma, Annie, and others has sent me this email as I have poor math and physics knowledge.
Hi Ron,
It's easy to get the cart before the horse in this sort of project. Ideally, the design and calculations would be done before building a boat, but your schooner is already in the water.
Well beyond the drawing board and calculations stage. All that can be done now is to try stuff.
Lighten the hull if at all possible, add the heaviest bulb she can carry without too much loss of freeboard (hull remaining above water).
Hot Tip - For the models, I like to allow 1/2 the boat's weight to be in the bulb
Regarding her failure to come about in strong winds - I see only a blank page for the video you sent, but here are several possible scenarios.
1 - She may need a larger rudder, to turn her head into the wind.
2 - She may have a "helm balance" problem, That is the fore & aft placement of the sail plan over the underwater profile.
Try moving the sail plan aft or the fin keel forward, or maybe just reducing the size of her jib.
3 - She may be overwhelmed by the wind, just not having enough displacement (weight) to provide inertia to maintain momentum into the wind.
I can help with math for wind pressure on your schooner's sails, for what It's worth.
.004 x wind (mph) squared = pressure (lbs per sq ft)
.004 x (20 x 20)
.004 x 400 = 1.6 lbs per sq ft
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sail area (sq ft) x 1.6 (lbs per sq ft in a 20 mph wind)
2.145 (sq ft) x 1.6 = 3.432 pounds of pressure on her sails
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Cheers,
Gary
