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 Ken Shindledecker on November 3, 2013 at 5:12pm

Two more pics of the narrow transom/moving against the water;  and the wide transom, where I'll be facing, rowing the other direction.  It's basically a punt, or chopped off driftboat.

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Permalink Reply by tungsten on November 3, 2013 at 5:24pm

I've built two similar boats,one the Hudson that you showed and one of my own design.My own design was simple to make as I learned what I didn't like from the first.Wide is good,especially getting in and out,Make it as long as you can,again helps with getting in and out.Rocker in the floor you'll only need a little.May not row as well but much more stable.

Pending on water conditions waves,current.This will determine side hight,do you need to lean over to get your dog back in?

I think your numbers are good,just add more length if it were me,and 48" at the floor.You can always raise it a bit to fit in the back of your truck.

A good design I think for your purpose is also a jon type,where the floor is flat all the way back and a little curve or rocker in the front.This gives the best stability,important I think with a 100lb dog.

 

Permalink Reply by Ken Shindledecker on November 3, 2013 at 8:09pm

I'm wanting/hoping to have a boat under 100#.  I thought 12' would be getting too long and heavy; I know it would track better.

I was thinking of having only one gunwale and glassing only the bottom and the SNG part and just seal and paint the upper part of the wood.  I might have to put in some sort of framework, or side stabilizers?

I could flatten out the wide transom end and just scoot a little back when drifting downstream, to get the bow up a bit.

I thought that a jon boat wouldn't have enough wood at the narrow end to support any/much weight?  Plus, I'd like a little curve in the bottom to be able to turn the boat in the river, but maybe that's not such a big issue, if it's not crazy water.

I have hauled the dog in over the side of my driftboat; I wasn't thinking of hunting out of this, but rather rowing to small islands/raised parts, where my waders would suffice.  Maybe I could get one of those boat ladders for dogs?

Permalink Reply by Dave Z on November 3, 2013 at 8:45pm

19" side height is good.  My "Z's drifter Pram" is a bit longer than what you want and certainly more weight wise, needs two guys to move it in and out of a pickup truck, or  one guy if trailered.  But that is what my side height is and it is a joy to duck hunt and fish from. wider, flatter, zilch o rocker will get your stability.  I seem to have some old popular mechanics 10' johnboat plans somewhere.  this would be what you want.

I'll get accused of blasphemy, I know but I seem to recall seeing 10' aluminum johnboats camo painted at Gander in the 450-475 price range.  Might be a tad more economical, but yeah, i get it, i prefer wood boats too.

dave

Permalink Reply by Ken Shindledecker on November 3, 2013 at 9:00pm

Thanks Dave!   Do you think a jon boat could be drifted in a little choppy water?  The biggest concern in some places I would/might go, would be the river rocks.  Could this water be done with a jon boat?   I was thinking more calm water, but wondering if this could be done without curvature to the sides?  Oh, is that 19" straight up from the floor, or the actual width of the plywood from floor to gunwale?

Permalink Reply by John Weston on November 3, 2013 at 9:52pm

that looks like a fun river to fish. where is that?

JW

Permalink Reply by Ken Shindledecker on November 3, 2013 at 10:09pm

The page I pulled it from said the Willamette,, but the McKenzie looks like this, too.  See some of the posts by Randy Dersham and others, 'bout the Whitewater Boat Parade on the McKenzie, in Oregon.

Permalink Reply by tungsten on November 4, 2013 at 6:34am

This was my second boat,would work well for what you want.11'3 loa

http://imageshack.us/a/img534/7281/boat002d.jpg

Rows very easy.

You could shorten it a bit and take out some floor width.This would come in around 100-110 lbs.I think 1/4" meranti with 6 oz glass on both sides will be 1lb/sq foot.You wont need any internal stiffeners.

Permalink Reply by Ken Shindledecker on November 4, 2013 at 6:44am

Very nice!!  What's the max angle/flare on the sides?

Is this mainly for river running?

Does this have a lot of rocker?

Is that a 48" bottom?

What is the actual width of the side panels?

One layer of glass, or two?

Is that weight, including the internal structures you have there, or basic hull wt?

I can see where I could take my model and narrow the back/narrow transom and make it more hydrodynamic.  I might take more rocker/rise out of the downstream, wide end and keep it up in the front.  I think I could also do with a little less rake on my narrow transom, if I keep the rise up.

Thanks for posting this!!

Permalink Reply by John Weston on November 4, 2013 at 7:49am

Ken, take a look at Brads Pram. you can google it up. I will go and look at it and post the site here later today if you haven't found it. I did some mod's to it to my want's. it is 8' but you can take it out to 10'. I like your model and what you have in mind may work too.

JW

Permalink Reply by Ken Shindledecker on November 4, 2013 at 9:32am

Brad's is a nice pram!  http://www.bradposey.net/pram/

It looks much like:  http://stevetheseadog.tripod.com/

I would want to rake the wide transom back a bit to address any sort of wave/heavy chop, drifting downstream.  But, overall, yes, this is the sort of thing that I think would suit me well!

Thanks!

Permalink Reply by Ken Shindledecker on November 4, 2013 at 10:34am

I forgot to post the pic of the panels in the original post:

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