Changing Plans

[Jay Herrick]

I started making a model of a 16' Pirogue.
I noticed after putting the sides together that simply pushing the sides in or letting them out I can really change the size & shape of this boat.

I'd like to allow the sides to assume a "less bent" shape when I build the real one. That would result in a much wider boat. In my model the sides want to flare out quite a bit anyway.

Having never built a boat I'm hoping somebody here can tell me if I'm making a mistake and should just stick to the plans.

Given approx. the same length 16', shouldn't changing the width from 28" to something like 48+" just improve its capacity?

[Bruce Hooke]

I would stick with the plans. Nearly doubling the beam could have all sorts of unpleasant consequences. The wider boat is likely to be much slower (a bit of a "pig" to put in indelicately). It also may change the way the boat floats so it could do strange things in that department as well. Finally, a wide, flat boat is very stable to a certain point and then once it is tipped enough it becomes unstable very fast, which is not necessarily a desirable characteristic.

For the kind of boat you are dealing with you might be able to get away with it but to do it well you really need to understand what's going on. I like to design boats in my spare time but I've been teaching myself about boat design for over 20 years and I've read a lot of books and drawn a lot of plans in that time. I am just now, for the first time, building one of my own designs(a 14' skiff).

When I create my own designs the first thing I usually do is try to find boats that are similar to what I have in mind. In your case, I would do the same thing but I would just look for other designs that are more suited to your needs than this design apparently is - and then build whatever design you find that best suits you. If you can't find any designs that are similar to what you have in mind then that should be a warning that what you have in mind is probably not a great idea...

[Venchka]

What Bruce said.

Pirogues ain't broke so don't try to fix 'em. My Cajun Cousins have been using them forever just the way they are.

If you need a boat with more capacity, pick an approriate design.

[Paul Scheuer]

Isn't a Pirogue a single paddle boat ? Wouldn't making it twice as wide upset the paddling mechanism ?

[Steve Paskey]

Jay: Forty-eight inches is way too wide to paddle -- if you want to increase the beam that much you'll be rowing. On principle I agree with Bruce, but how far wrong can one really go with the shape? And, in fact, it seems to me that it's already been done. Have a look at Bolger's WINDSPRINT:

www.instantboats.com/windsprint.htm

Pirogue shape, 16-feet long, with a 54 inch beam.

[Jay Herrick]

Thanks for the replies!

I had not even thought about paddling vs. rowing, I just noticed that the sides wanted to flare out on their own and letting them would give me quite a larger boat.

I think because it's my first boat I'll stick with the plans, it's just very interesting to see what happens when I manipulate this little model. I can really picture several boats by pushing the sides in or out, even pulling them a bit, chopping off the back and adding a flat transom.

I don't know what I'm doing yet, have not even cut a single piece of wood on my first boat and here I am planning the newt two

[G. Schollmeier]

What happens to the bottom when you let the sides flare out? Move the sides of your model in and out and watch the bottom. I’m thinking as the flare increases the stem and stern will turn up increasing the rocker.

Gary