Pram Design Help Wanted/Needed!

Hi All!

I'm wanting to build a ~10pram for hunting with my dog 'round lake/marsh margins and for  crossing the river and mellow water anchoring and fishing.  I weigh 220#; dog=100#; gear 50-100#.  So, I'm looking for something to safely float ~400-450#.

I'm thinking that I need a compromise.. neither a river runner, 'nor a long distance racer.  I just want to paddle/row ~100-200yrds to get where I and others can't go with waders.

This is modeled so that the wide transom is headed downstream, when drifting; or when rowing somewhere, the narrow transom it headed in the direction of travel.

I first modeled a Hudson Springs Pram:  http://www.duckworksbbs.com/plans/messer/hudson_springs/index.htm

I modified it by raking back both transoms, for river use.  I then widened the sides and freehand cut a bottom out and created the sides and transoms to fit.

I don't know how to use the FreeShip software.  I might figure out Hull.  But I need some sound advice on how to modify what I have.  I've attached pics.

1"=1'   So the bottom=8", or 8' long;  Bottom is 45" wide;  Narrow transom is 27" at bottom;  Wide transom is 40" at bottom;  Beam is~ 66";  Transom top to top is 9'10.5"; Sides are ~18-19" actual height/width and just shy of 10' long.

There's some rocker in this, but not much.  I'm thinking I could easily narrow the narrow transom some and a touch on the wide transom.  I'm thinking that this is way overbuilt for the weight I've given above.

Could I go narrower than 45" overall?  I've seen prams from 38.5" to 48" wide.  Could I go a little shorter on the side height?   I'm really open to all ideas!

Many thanks!   Ken

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Permalink Reply by tungsten on November 8, 2013 at 7:32am

When I lofted the bottom I used 10" stations,i can't remember now by how much but the curve was increased at ea station.So rocker increased as it went back.Hope this makes sence.

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Permalink Reply by Eric Loudenslager on November 8, 2013 at 8:05am

Tungsten,

Based on your boat 011.jpg picture I gather you built open-side up without using a strong-back. You built using the S&G approach with the panels establishing the boats shape. What size bottom did you use?

Permalink Reply by tungsten on November 8, 2013 at 9:32am

Yes open side up.I used 1/8 material to mock up a full size model.This way I could see it and measure rocker,i could also sit in it to see if it was right.Once I got it right I used these panels as templates.The bottom was 48 wide and 10' long in the picks the clamps are 10" apart.I ended up cutting a little off the back as somehow my sides were a little short.Still haven't figured out how that happened?Could have been the whiskey:)

So it looks like I used 40" to curve the stern and 30" to curve the bow.Hope that answers your question.

 

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Permalink Reply by Ken Shindledecker on November 8, 2013 at 9:50am

Very informative!  Thanks.

Permalink Reply by tungsten on November 8, 2013 at 1:32pm

I think I showed the back twice,this is the bow.So 3 10" stations to create the bow rocker.You can see the 4th screw back is in a little so a little more then 30" was used and the same for the rear of the boat.

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Permalink Reply by Ken Shindledecker on November 8, 2013 at 1:56pm

What did you use for a batten?... How thick and wide to give you a nice curve?

Permalink Reply by tungsten on November 9, 2013 at 9:52am

I'm not sure on its size,1/4x 3/4 maybe.It was a piece of 1/4 cut sapele,(it has really straight grain) that was rescued along with a bunch of other pieces.Makes beautiful gunnel's but its a little soft for crashing and banging.

 

 

Permalink Reply by Ken Shindledecker on November 9, 2013 at 10:36am

Okay..... so this is gonna be blasphemous.... but I'm looking into one of these, for my duck hunting needs (they make other canoes, too).. looks really stable:  http://www.castlecraft.com/sportspal_wide_transom_canoe.htm

BUT/AND,, from what I've learned from y'all and playing 'round with cardboard, I see how I can make a drift pram, more suited to river use.  I'll keep playing with designs, but since my garage is messy and very cold, it'll be Spring, before I get serious about the actual build.... Something to really look forward to!!  Thanks again, to all of you!!!

Ken

Permalink Reply by Ken Shindledecker on November 10, 2013 at 10:25am

Nevermind!!   I've been doing research on that foam-lined canoe and found a real down side to it!!  http://www.washingtonflyfishing.com/forum/index.php?threads/dont-ta...

Permalink Reply by Ken Shindledecker on November 12, 2013 at 6:18pm

So, I've been chewing on what many suggested 'bout building a jon boat,, and that I need a boat for every purpose.....

First, I like that pram I worked up, but don't think that I'll like it for marsh use, getting from pt. A->B....   So, I've been looking at canoes... Too tippy for my comfort level, with a 100# dog.

But where I'm thinking now, is sort of a hybrid of ideas.  I found this Wenonah Backwater 15' canoe:  http://www.wenonah.com/products/template/product_detail.php?IID=230...

And you're asking... "why not just by the darn canoe and be done with it??!"

Well, I'd like to build something and secondly, I don't like the narrow space in the front of the canoe, unless I stuffed it with decoys.

This boat is 41" at the gunwales, w/ 37.5 @ waterline and it's 15' (I'm assuming that's around the gunwales).  Nice L:W ratio!  I'm not concerned with going more than 200yds, one way.  I wouldn't be paddling/rowing miles in it.

My idea is to take this basic design and chop the front end off to somewhere 'round the front seat.  That would become the stern.  I would keep the general shape, but would widen it to ?? 43"???, and put a little rocker in it and flare the sides, especially up front to bring the nose up out of the water and I would put a raked transom in the front, or even do as some have suggested and add some jon cut to the front.  Though, I think it would glide and ride better if I just started to flare the sides.  I'm thinking ~12 gunwale length??,, more????

So,, does the design concept sound reasonable?

Could I do this with ply/glass and keep it under 100#

Would this design safely carry 400# at 12'x43"?

Thank you all for your advice and especially your patience in my process!!

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Permalink Reply by Phillip Westendorf on November 12, 2013 at 7:16pm

Ken, 

If you have a canoe already, there's another simple solution.  Add a a set of outriggers.  Google "canoe outriggers", there's a bunch of options; store bought, DYI  (Wood, plastic, etc.) and lots of pictures.  You could use this to practice your wood working skills. 

I have considered a set for my 16 ft. Stripper Canoe, but have not got around to it yet.  I was planning on making a pair of reduced sized models of my canoe and adding them as outriggers.

Just another $0.02's worth.

Dorf

Permalink Reply by Eric Loudenslager on November 12, 2013 at 6:58pm

Ken,

There are almost limitless possibilities that could serve your purpose. All would work, all will have compromises. For some the compromises will be in construction difficulty, others will be limits to performance.

In the last reply you propose a canoe, but then chop it off and increase the width to start to resemble the prams that have been the early focus of the thread.

A canoe would serve you well. It could be transported on a car top and will weight under a hundred pounds. A 15 or 16 foot general purpose royalex like the old Mad River Explorer, Dagger Legend, Old Town Tripper. A canoe as short as 14 ft could work in the right hands. But the canoe will be a little tippy, and challenging to cast standing up.

Jon Boats, prams, etc would also work. Better stability for casting and the dog, but less dynamic paddling or rowing....but your distances are not long.

In the end the final decision will incorporate all your important needs and will serve you well.

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