Another two sheet rowboat design- "Big Guide"

[flo-mo]

For those of you who like the tiny one sheet canoe "Little Guide" (http://forum.woodenboat.com/showthre...ne-sheet-canoe) but said it is too small for them - here comes "Big Guide":

A forumite wrote Little Guide is a water toy and of course he is right.
So I made a similar design by the name of "Big Guide" that could be made of two sheets of 6mm plywood. It is as simple as can be and should make a serious rowboat.
For me it will not be possible to build it within the next six months but I made an accurate 1:10 scale model using 0,8mm birch plywood. I think it should be an easy build and a fast recreational rowboat for protected waters.





Big Guide and Little Guide side by side


row


the boat and the two sheets


detail

Here are the specifications:

LOA 15'8"
Beam 42"
Length on waterline 15'6"
Beam on waterline 35"
Cp 0,50
Centre depth 13,5"
Draft 5"
Displacement 500 lbs
Estimated weight 70 lbs

[keyhavenpotterer]

That's really nice, quite Adirondack-ish and only two sheets. A low cost car top rowboat at last.

1) would it be possible to supply panel offsets etc as with the Little Guide.
2) Is the layout very tight as before, so a knife cut is required or could she be CNC cut?
3) I have some lovely high quality Bryunzeel 4mm ply in stock - would that be ok to use?

Thanks, Brian

[htom]

Oh my.

[huisjen]

Very nice.

Could you possibly give us a pattern for your manikins? Sort of an outline, with marks for where to score the foamcore, front and back? Then we could scale them as needed, print, paste, and make similar ones.

Dan

[openboater]

It really is fun to see an artist at work. Beautiful and functional.

[flo-mo]

Manikins:


Red line: Front side cut
Green line: Back side cut

[Soundman67]

Very nice looking boat. Great to have you aboard the forum. I was wondering if the design could be modified a little so that I could start with the 2 sheets of ply scarfed together and then start cutting. seems to me it would be much easier to keep things square that way. And I really prefer the look of a scarf joint to a butt block. Thanks for the great plans.

[Peter K]

Big Guide is another very elegant design also with minimal plywood usage. You have a real talent for this , keep it up.
Oh, and can I please have the offsets too?

[flo-mo]

Offsets:

[keyhavenpotterer]

Thanks, flo-mo for putting up the off-sets.

Brian

[aldebaran]

Very nice rowboat. Fast and tender?
I love the manequins, but its not in scale on the photo?

[Peter K]

Flo Mo...thanks for the offsets, its very generous of you !
Cheers Peter

[Woody Jones]

Thanks for the offsets Flo Mo! Hope your back is on the mend. Please keep us updated on how your "experiment" works out.

Woody

[Erik le Rouge]

Big guide : Should be a good rower. Lines fit between those of a canoe and adirondack guide boat and bottom is dory-like but a lot finer.
If I had to build her it would be 6mm plywood (4mm may be a little fragile ?) with just enough fierglass on bottom in and out up to the first shine. Plus I'll add three seats (canoe seats ?)+ framing at seats to add rigidity (if built 4mm).
No need for enclosed flotation : Canoe flotation could be laced in bow and stern when needed on big lakes or open sea...

[keyhavenpotterer]

This picture



has got me thinking.

The drawing of the panels under the hull. Glue the two sheets together. Then you could almost picture cutting the panels out and leaving them in place just like the picture. then loosely stitch the panels together will fishing line. then draw the panels up off the floor/jig, insert seats and spreaders as formers, and tighten stitches. Hey presto, panels all under control and hull formed.

Brian

[aldebaran]

The top panels must be glued the other way round I think. They are wide in the middle and narrow towards the bows.

[keyhavenpotterer]

Think you might me right there.

Brian

[mommicked]

This reminds me of both the Eureka 155, and also JEM's BHC (Big honking canoe, an Adirondack Guide Boat). What lovely designs you make! You need to think seriously about making designs for sale.

I'd love to see you do some 3 sheet sail boats, some flat bottom skiffs, and some boats that can be cut with a saw instead of a razor. You are quite talented sir!

[flo-mo]

Here is a pattern with a 10mm grid for the round part of the bow requested by a forumite. To answer another question: If you use 6mm plywood there is no need to sheathe the hull with fibreglass cloth - glue and tape and painting the hull should be sufficient.

[Erik le Rouge]

Thanks for the information

[flo-mo]

Seat arrangement and decks:

[flo-mo]

All dimensions in centimeter

[aldebaran]

Very nice.

But, the manequins, are they in scale?
To me it looks like they are basketball players.
On a long boat like this, it could be interestin with a moveable center twart, so that the boat could be rowed by either one or two persons and be in balance

[flo-mo]

The manequins are in scale. Maybe it's the view angle. They are equivalent to a person 6' tall so three of them would exceed max. capacity. It's just to show the use of the seats.

A movable twart to provide positions for one and two rowers is something I am considering but have not found a solution yet. I know the arrangement for the Herreshoff Rowboat by John Gardner. Another possibility are straight seat risers. I am not realy pleased with these solutions so maybe you know another.

[wayne nicol]

i know what i'm gonna do.
simply build two boats (they look so easy and quick and cost effective), then my wife can row her own boat, certianally cuts back on the divorce rate! but what's she doing out of the kitchen anyway!!
seriously though, for me, each of us in our own boats with a kid in each, and all picnic praphernalia, will just about be perfect.

i would love to use a small sail when conditions are ideal though, anybody any ideas on step and daggerboard or leeboard placement, and sail plan. thought a small balanced lug might work well for the ease and simplicity of it- short spars etc etc.
an attachable bracket to steer with one of the oars, that attached on the gunwale. i might use riser block on the outwale, that would allow for a thwart going from one gunwale to the other, with locating blocks that slot into the spaces in the outwale, extending over either side, with the oarlocks to hold the steering oar.
gonna install bulkheads under the decks, for floatation, but with small hatches, to store rain gear etc.

waiting for my ply to arrive, so that i can get started!!!

[aldebaran]

Flo-mo

This Ellen 12 has a moveable centertwart:


And this Ebenezer 11 has another design:

[flo-mo]

In a PM I have been asked about the dimensions of the gunwales. I suggested 3/4" x 1" for inwales and outwales.

After some consideration another idea came to my mind.
Start with a strip 3/4" x 1" and make a slot, either with a router or a tablesaw, so the 6mm plywood easily fits in. Glue it to the sheer-panel before assembly. It adds rigity to the otherwise wobbly free end of the sheer-panel while assembly, makes it easier to install the temporary spreaders, covers the otherwise unprotected end-grain of the plywood and rises freeboard by half an inch.




After the hull is assembled and the spreaders give it the right shape, mount two strips 5/8" x 1" to complete the gunwales.

[wayne nicol]

great idea.
anybody any input for sailing rigs etc

[aldebaran]

Wayne

This hull is narrow and with a lot of flare. A typical rowing hull. This means that it´ll not be the best sailor. You can put sails on it of course, but it has to a small one. I´d say 35 - 40 sqf max. and it has to be LOW. probably a 2 mast setup.
Since the hull is basically a canoe, take a look at canoe sails. Maybe read Todd Bradshaws book about canoe rigs and sails. I wood use a leeboard on a hull like this one.

[wayne nicol]

thanks for the help and the input.
not really planning to make it into a sailer- would just love to sail a bit when conditions are ideal for it.
maybe i should just keep my sailing for the sailboats.
thanks
wayne

[mommicked]

I could see the temptation to build the boat, but leave the stern with a wine glass transom, like a Whitehall type rowing boat, as well as the canoe version. It would make a swell rowing or paddling boat in either version, I think.

[flo-mo]

I am not a sailor and I am a mere amateur at designing boats. I purchased Todd Bradshaw's book a while ago and now I tried to make a sailplan for big guide. Sail size is 42 sq.ft. Comments are appreciated. Thank you.

[aldebaran]

I would rake the mast some 10- 15 degrees backwards and I prefer balanced lugs to standing lugs.

Another thing is that I think your romax design will be a better row/sail combo. Its wider (If I remember right)

[flo-mo]

Thanks for your input. Please excuse my ignorance - to rake the mast backwards, what is it good for?

Romax should be a bit more stable than big guide and a little slower. As you stated above, both designs are similar to a canoe so with the right sail rig performance should also be similar to a canoe equiped with a sail.

[aldebaran]

Raking back the mast looks better IMO.
A standing lug like on your drawing looks like it is raking forward when you´re sailing and that realy hurts my eyes.