You have a perfect application for electric power where weight and short range are not negatives. As long as you have access to shore power for charging you will love the electric drive.
(8) 6v 66# batteries would give you about the right ballast and enough power to motor for 6-8 hours at 3-4 mph, probably 5 kts for at least a couple of hours.
You can use a 48/12 converter and run your house loads off the drive batteries as long as you are careful about watching battery state of charge.
One of the 6ish HP 48v motors would be a good choice. You will have to experiment with drive reduction ratios and/or props to get the motor loaded correctly. Be sure you have plenty of tip clearance between the prop and hull and use a stout shaft (at least 7/8") in spite of the low power. The electric drive will be so silent you will be able to hear prop rumble or shaft vibration taht you'd never notice with a diesel..
If you have been reading here you must realize that the 'buy all the components myself and wire everything up' is quite a science experiment. If that sounds fun go for it, or avoid all the fun and spend a couple of extra $1000 and get a drop in unit.
A 4kw Torqeedo outboard in a well would be an interesting choice too if you could engineer the well to be unobtrusive. I can't imagine the horror of hanging an OB on a bracket on the stern of a lovely canoe yawl.
BTW, if you are not already, you should frequent the Woodenboat Forum. They will drool all over a new canoe yawl design.
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>On Fri 27/05/11 1:57 PM , "garren1956" wrote:
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>Greetings from Montana.
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>A designer is finalizing design and specifications for a 24' canoe yawl, DWL about 22', centerboard with 28" draft with board up, and about 4600 pounds displacement. Hull is round-bottom with hull speed around 5-6 kts. Construction is sheathed strip plank.
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>I have been following this site for several months and have learned quite a bit, but not quite enough to feel comfortable designing an electrical propulsion system myself. Can someone suggest a system (or components) that I could forward to the designer so that its weight and specifications can be incorporated into the design?
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>The design requires about 400 pounds internal ballast which hopefully will be satisfied somewhat by the weight of batteries. Can battery weight by cell type be generalized?
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>I don't want to have a generator and likely won't experience may lee shores with reefs, rocks, and frothy white water. I would mostly be sailing on large lakes and reservoirs in the western US. But the prospect of the Inside Passage is always out there. I realize that constitutes a lot of lee shore.
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>I think one battery should be fine for house needs. A few lights, maybe music, and recharging computer batteries is all I contemplate. Would a wind generator or solar (or a combination) be adequate for house needs or more of a hassle than it may be worth?
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>I want a system that is almost idiot-proof to be used primarily to negotiate docks and for passing beneath bridges, but also sufficient to motor the boat for several hours at less-than-hull design speed. I'm not an electrician - I'm a biologist - and wonder whether a drop-in system makes the most sense for us electricity-challenged folks.
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>Thanks for any advice and let me know if I have overlooked something important with the information posted here.
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>Gary Davis
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