JEM Watercraft
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Cargo canoe
http://www.jemwatercraft.com/forum/viewtopic.php?f=17&t=2950
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Author:  Oldsparkey [ Tue Oct 13, 2009 8:25 am ]
Post subject:  Re: Cargo canoe

Stitch and glue is easier to build and I would say quicker then the strip. If you have not built a boat I would suggest the stitch and glue to get all the basics of building down and understood. Then if you would want a strip , you have built one boat and have it to use while building the other.

They are nothing more then wood , epoxy and fiberglass all mixed up and put together. It's just how you put them together. :lol:

Chuck

Author:  Darrells [ Tue Oct 13, 2009 7:52 pm ]
Post subject:  Re: Cargo canoe

I would not say strip building is harder, but it does just about double the time required to build a boat. I do agree that you should build a S&G boat first for the simple reason that it is faster to build . Get this one built and if you like building boats dive head first into a strip boat. The second boat I built was stripper and I would not take for the experience I gained from it. Besides it looks really good. I am talking with Matt right now about a second stripper. The Northwind.

Author:  Yohan1973 [ Thu Oct 15, 2009 1:48 am ]
Post subject:  Re: Cargo canoe

Matt, although the DK 18 is a bit too much boat the 15 is on the lower end of desirability but still with-in the zone. Is it possible to widen the transom a little and lessen the rocker without adding all of the added structure that the 18 has? As is, is it possible to stand and cast with comfort on the 15? What I would like to eventually do is put a small poling platform on my future skiff. Maybe something like this:
Image

Author:  jem [ Thu Oct 15, 2009 5:09 pm ]
Post subject:  Re: Cargo canoe

Well there's an issue in designing a hull such as this. Hopefully I can explain it.

If you go by the USCG regs for max HP allowed for a boat 17' x 40" (40" at the transom) you can put up to a 15 hp engine on it. A boat designed to take a 15hp engine will be a lot heavier that a boat that only needs to accept a 3hp (typical trolling motor).

To address this, I can do one of 2 things:

1) Draw it for the 15hp rating.
Result: A heavier, more expensive to build boat.

2) Draw it the same overall size just with hull strength only needing to withstand a trolling motor.
Result: someone will inevitably put a bigger engine on it and get hurt or worse. There goes my reputation.

3) Keep the same general dimensions but taper the end in for a narrower transom that can only take a samll outboard per USCG regs.
Result: A hull with a 48" max beam with a 27" transom and reduced stability.

There are ways to manipulate the numbers for maximum rating but I will always error on the side of caution.

I'd love to explore the idea further. so let's hear your thoughts.

Author:  Yohan1973 [ Fri Oct 16, 2009 10:24 am ]
Post subject:  Re: Cargo canoe

Hey Matt, thanks for the reply. Let me explain the picture...I only posted it to show the poling platform configuration. I'm not interested in a 15hp powered boat. I simply wanted to show you the poling platform design. I could deal with a 6hp powered craft with ease. I've been looking more and more at your DK dingy too. Your sister site has some great pictures of it. It's a very nice design.
Now, about this platform. I think that in terms of usability it's a great design. However, it places some very dynamic forces onto the transom. Dealing with motor torque is normal for the transome but this sort of poling platform configuration places a new dynamic force dirrectly in play with the transom. I believe that beefing up the transom thickness is only part of the solution because you'd still have to transfer the load and it's nonsymetrical overturning moment to the hull where it attaches to the transom. What is the best way of doing that without adding a deck at the top of the transom? I hope I communicated this well. I'm rushing...got to get to work...


Edit:
I forgot to share this article too:
http://troutunderground.com/2006/09/08/ ... th-images/


And these:
http://www.flickr.com/photos/10cocktail ... akestream/

Author:  jem [ Fri Oct 16, 2009 5:39 pm ]
Post subject:  Re: Cargo canoe

It won't matter where you attach it, the center of balance will be a factor or you standing on the platform.

On a hull with a narrow transom width of 27", I'd worry about the hull squatting bad in the water. You could incorporate a motor well (split tail) design and that would move the motor and poling platform (assuming it stays above the motor) forward while having some buoyancy from the "split tail".

The motor well would have to be just wide enough for a small motor.

Author:  Yohan1973 [ Sat Oct 17, 2009 12:53 am ]
Post subject:  Re: Cargo canoe

jem wrote:
It won't matter where you attach it, the center of balance will be a factor or you standing on the platform. .
I either didn't explain the intent of my last post or I'm not understanding your reply. Let me explain myself another way. Typically a poling platform is mounted on a horizontal surface (the rear deck) That sort of configuration allows the load to be evenly transfered to the hull as a compression force. However, mounting the platform to the vertical plane of the transom causes the load of the poling platform to be transfered to the hull as a shear force with an overturning moment. My concern in this case is...How to attach the transom to the hull in such a way that the shear force of the poling platform and a live load (live load= me) doesn't rip the transom off? Am I over-concerned?

jem wrote:
On a hull with a narrow transom width of 27", I'd worry about the hull squatting bad in the water. You could incorporate a motor well (split tail) design and that would move the motor and poling platform (assuming it stays above the motor) forward while having some buoyancy from the "split tail".
Are you refering to modifications to the DK? Funny thing is, the picture I posted above is of a craft with a 27.5" transom. I think it does squat a wee bit. Refer to the quick sketch below for my take on the topic:
Image



http://img02.imagefra.me/img/img02/2/10 ... 309bf1.jpg



P.S. I just realized...the sketch doesn't illustrate any deadrise in the hull. I would go with a little deadrise. How much...I don't know. I don't usually design things that move...especially in water! lol

Author:  jem [ Sat Oct 17, 2009 9:05 am ]
Post subject:  Re: Cargo canoe

The light bulb of clarity illuminates! :lol:

Ok I get you now. Will you be making your own poling platform like in the picture (or buying it)? In either case, you cold install some longitudinal bracing on the transom to help with the load of the platform.

Are you going to use the DK dingy 15 or looking for something longer?

Author:  Yohan1973 [ Sat Oct 17, 2009 11:50 am ]
Post subject:  Re: Cargo canoe

jem wrote:
The light bulb of clarity illuminates! :lol:

Ok I get you now. Will you be making your own poling platform like in the picture (or buying it)? In either case, you cold install some longitudinal bracing on the transom to help with the load of the platform.
Are you going to use the DK dingy 15 or looking for something longer?

This will take some time for me to accomplish. I'm still searching for an ideal hull and learning more about all of this boat building and designing stuff. The DK dingy IS on my list though.

When I finally get going, I will just have the poling platform fabricated for me.

I posted the sketch because I wanted to illustrated the basic program that I am shooting for. A very simple and open floor plan. I think your dingy is a possibility. However, transom width, and rocker are my only concerns. I agree with you, too narrow of a transom could/would lead to squating but I also think that a boat with rocker or a lot of side wall flair would also cause the front end to ride high while poling. Is that a far assumption?

I have been trying to collect as many pictures as I can of the Dk dingy too. I still do not know much about it's stability though.

So far these are the hulls that I have been following closely as posibilities:
Your DK Dingy and maybe the mini skiff
The 18' boat from another site.
David Nichol's Lutra Laker (Oddly enough I recently ran across this one and it has the exact dimensions I've been spouting off...but it is neither Stitch and glue nor strip built)
There are a few other strip canoes I've been eyeing too but those are falling off the list.

Author:  jem [ Sun Oct 18, 2009 9:11 am ]
Post subject:  Re: Cargo canoe

The DK 15 does have a good amount of rocker aft.

What kind of proportions for the sheer height are you looking for? Like a canoe or a power boat?

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