After many exchanges on boatdesign.net, my thinking and model making, I've decided to build the following:
A narrow, 20 ft. long "stitch and glue" boat powered by an electric motor.
Beam will (probably) be 28 inches (for ease in car-topping.)
The boat will be built in two (apx.) 10' sections on a 16" x 10' "strongback" as suggested by David L. Nichols in his "Lapstrake Canoes."
The boat will be used only in summer for quiet, usually evening, cruises on a fresh water lake in southern Wisconsin, hence its name; "Twilight."
The boat will usually carry two adults, each in a comfortable seated position, facing each other. (I've given up on "comfort" -- passengers will sit with legs "straight out.") Let's guess at weight of two passengers -- 180 x 2 = 360 pounds.
The boat will come apart in two 10 ft. pieces, for storage and transport. (The "transoms" of each section will be joined -- and divide the cockpit in two.)
Assembly and launching will usually be done from a pier.
The LWL will be about (a bit less than) 20 ft.
Maximum width will be about 28 inches, maybe a bit more.
Cockpit width will be apx. 20 inches at seat back -- same as my office chair -- with narrow side decks.
Two 6 volt batteries will be used to power the 12 volt Minn Kota trolling motor. Batteries will be located at front and back of joined cockpit, beneath deck(s). The batteries will be located where "transoms" meet at station 10', one on each side of "joined transoms." The two six volt batteries weigh 72 pounds, total.
Here's a $20 battery tester that might be useful.
Latest model (below) shows 12 inch high (vertical, no flare) sides on hull. Can sides be lower? I think not.
Decks will be crowned?
"Twilight" to be powered with a 40-pound thrust Minn Kota trolling motor -- the same motor used to power an earlier, smaller version of Twilight. (Much more at grantmaclaren.com/zac)
Here's a video with a smaller trolling motor powering a 14 ft. boat:
Steering will be done via a push-pull system, with crank atop the "rudder" post. We've had very good experience with this very simple and reliable rig.
Boat will have white hull and "natural" decks, and of course, provisions to fly an ensign at stern -- and owner's burgee at bow.
Storage for a wine bottle and a rack for two wine glasses will be provided.
I've built a few small boats, but this one will be of my own design and concept.
Michael Storer, designer of "Beth" comments on the building of "Kanangra:"
"It is quite amazing how just the right amount of sheer and deck camber disguises the box shape of the hull.
"Get the Sheerline right and the boat will look perfect - even if is a square section hull.
Put it on the water and the chine almost disappears from sight, but still allows the bow and stern a nice aggressive look."
From: Grant MacLaren (firstname.lastname@example.org)
Sent: Thursday, December 4, 2008 03:27 PM
To: Jim Michalak (email@example.com)
Subject: "Twilight" - an electric boat for calm water
Hello Jim, Grant MacLaren here. We met at Rend Lake Messabout 2007. I am the guy in the little electric boat described here: www.grantmaclaren.com/zac
I would like to build another boat as described here: www.grantmaclaren.com/twilight. I've purchased your plans for Piragua 18 and intend to use some of your details, although I intend to build on a strongback.
I've made a number of models, the latest 20 inches long (1 in = 1 ft) with 6 inches (of full-scale) rocker. I now intend to build full-scale using luan, then build another, "final" version using some marine ply I have on hand. My two questions are:
1) Do you think it will be stable enough for use on very calm water? and
2) How high should the sides be to carry 450 pounds? (I'm thinking 12 in. to 14 in.)
If you need more info, please let me know.
Thanks very much,
On Dec 12, 2008, firstname.lastname@example.org wrote:
Grant, sorry for the late response.
I do think your boat will be stable enough to use in calm water provided you don't stand up in it. To stand, the bottom should be at least (?) wide for most people, but you can't paddle a boat that wide. A quick figuring shows me your boat, 20' long and 2' wide on the bottom and with a 6" rocker will float about 600 pounds OK. A boat like that might weigh 150 pounds if not heavily built. Then the motor and battery will add another 100 pounds, so that leaves about 350 pounds for people. To float 700 pounds total I would make the rocker 7" and use the deeper sides. Jim
Thanks for your thoughtful reply.
I am building another model -- this one of wood -- right now.
The model shop's balsa is 36" long, so the scale is 1-7/8" = 1'.
I'll have some photos soon, and by early next week will
post them on my website. (That's been done . . . gem) I'll send you notice when I've got them up there.
As I said earlier, this boat is being built for one purpose --
quiet, slow cruises at twilight (and/or dawn) on a small
southern Wisconsin lake I've known since being a kid there.
I really like the looks of the "Beth" hull by Michael Storer, so am keeping it in mind as I go:
(Click on above image for a larger version.)
Thanks again for your help. I'll be in touch again.
Here's a model of the 20 ft Twilight, built of balsa and tagboard, floating in a sea of tagboard with a skipper to scale:
Where has this year gone? It is now December 6, 2009 and today I've taken this photo to show Randy Spurr:
Doug Hylan (of www.dhylanboats.com ) designed and built the skiff pictured below. Although the boat can be equipped for sailing, it turns out the designer and his wife use it mostly for wine-and-cheese sunset cruises. See WoodenBoats' "Small Boats" magazine, 2009 for more about this very nice "twilight cruiser."