C'mon, sombody post on building a Jon boat or a Pram.

I really want to build one. I just dont want to be the one that everybody else learns from.
I need a small 12' or less, boat to fish in. I want to row it. I want the bottom to be flat and wide so I dont tip this one over as I have in the past with the V-bottom boats.
I have tried unsuccusfully to use software to draw what I want. Somebody put one up so I can dream a little.

 

If stability is an important criteria for a 12ft boat that is being rowed then you should consider a catamaran.

I did the attached sketch for my brother-in-law for a small cat limited to 8ft length. The aim is to stow it sections across the back of his motor home. It is designed to be paddled by two but could be set up with a central seat for rowing. A 12ft version say 5ft overall beam would be a very stable platform.

These hulls are very simple to make. I have found door makers here who discard 2.4m by 0.3m offcuts from 2.4 x 1.2m sheets of ply. These sheets are 7mm thick for outdoor use (not marine ply). You could probably get away with 4mm thick ply if you were careful. Even thinner if it was glass covered.

There are also twin hull prams with open hulls that might be worthwhile considering. I like the idea of enclosed hulls because they cannot be swamped.

This link shows the performance version of a rowing cat designed for rough water. (It did not achieve commercial success):
http://www.rocat.co.uk/
So a 12ft cat would be more like the col_cat pic but Rocat shows the sort of sea conditions that a cat will take. I have an aluminium cat very similar to Rocat but is pedal powered. I use it as a test boat because it is stable. I can stand on one hull without any risk of rolling.

Rick W

 

Pregnant again ??

 

Maybe this,
http://www.bateau.com/studyplans/GF12_study.htm?prod=GF12
Gary

 

LOL, your thinking of a preambulator! Thats needed after the water done broke!

I had a sliding rowing seat in my 12' v-aluminum. It turned out that the seat needed a little more inventing.
I slid it toward the bow, it went right over backwards with me. I fell over backwards and partly out of the boat. I was laying over the Fwd bow and the water was pouring into the boat.
I had to make a decision. If I tried to get back into the boat there, the boat would fill up and sink. So I tumbled on out of the boat and hung onto the sides, as I swam the boat a 1/4 mile to the beach. I always wear a PFD. I was OK, the water was warm and it was still a few days from the Saturday night bath.

I have a larger 15' Aluminum Jon boat. Its very stable with its 48"bottom. So I thought I'd get a smaller Rowing version of that for the small lakes.
If it was 10' it'd fit into the back of my Pickup. For 12' I'd need a trailer.

Years ago I fished out of an 8' Pram built from a Mechanix Illustrated article.
It was great.
However now I think I'd like to add a Reclining seat back to my rowing seat for those times when I'd like to rear back and rest. For that kind of monkey business you need a 10' or 12' boat.

Duluth, thanks for that link. If I see something I like I'll doodle with it and see if I can come up with something I can build.

 

Gary that one looks pretty good. Man I love the way those CAD pictures come out. I am a wannabee about that CAD stuff.
Dick

 

I suggest you research available designs on the net. Try Bateau.com http://bateau.com/categories.php?cat=28. No I don't have any affiliation with them. I did build a 12 foot rowboat from their plans and it was relatively easy to build and inexpensive. You can see it at http://newboatbuilders.com/pages/fl12.html

However, one thing to keep in mind about jon boats. They have great initial stability, meaning they seem very stable at low heel angles, but they reach a certain point and they flip very suddenly. And the smaller they are the more they are prone to do that. Of course this is a generalization but I spent years looking at boating accidents and jon boats unfortunately were used in a high percentage of them. They are intended for flat water and people use them for all kinds of things they were never intended for. As long as you use them for what they were intended they are great boats.

 

Ok...here ya go. A quicky drawing of what I think you are looking for from your description. I added a bit extra flare to the sides for additional reserve stability. Length is 12 ft and beam is a smidge under 4 ft without gunwales or trim. Waterline is at 300 lbs gross wt. in fresh water. Waterline beam is 38.5" giving about 3:1 at an LWL of 9.75 ft. A bit beamy for serious rowing but decent stand-up and cast stability for the length. It should also be very efficient with a trolling motor when you get tired of rowing.

Steve

 

what category is obsessed?

Nice drawing. Looks like it would work and be easy to build.

 

Holy Cow, I just dropped by tonite to see how this was going and discovered all those new posts. I 'm not getting a tickler when I get a new post.

Anyway, I appreciate your thoughts Ike. I believe you when you say they seem to be stable until suddenly they go over. A Jon boat is like that.
But those little Aluminum semi-V's are much worse for an old fart because they fill with water so easily, even if they dont flip.

Lewis, I'm gonna send you a message.
Thanks, you did a bangup job on that little jon boat.

 

Means I go through all the threads in 5 different forums on boatbuilding and design BEFORE I check my email, or anything else (usually...unless I REALLY gotta go!)


Looking at shortening it to 10 ft, raising the bow curve for better shore ramming and maybe some other stuff.

 

WHoa, I dont think you had to change anything on your hull design. I liked it the way it was.
For rowing, your bow was high enough with a good skid angle.
If I had a little guy sitting up front, your angle would keep his weight from steering the boat. Also, I can mount the battery up front with your design and that little bit of weight wont steer the boat.
Both those circumstances work against the Rower if you have a V design or a sharp prow.
Your design is perfect for a rowing flat bottom boat.



For Ramming (beaching in the nice guys forum) it had a great angle too.
And...it was flat across the Beach surface so the boat didnt roll out from under me as I clumsily scrambled from my rowing seat, the length of the boat, to the beach, over the bow.

If I could draw, or use your CAD program, I'd show you what the seating arrangment I think I'd like. But for now you'll have to read that PM.

PS: Your email didnt work. I got the email back saying your address was not a good one. So I reverted to the PM.
Thud

 

Here is a slde show of the Rolling/Sliding Rowing seat I made up of some Stuff I found in my Barn.
It's setting on some Oak. There are top and bottom roller skate wheels. The bottom wheels are to keep me from falling over backwards.
This works great, and when I get another boat this is what I want to do for the rowing seat. This one could use some engineering and if I'd have thrown a little more money at it, maybe t could even be better. Eat your heart out all you engineers!
You just click on the picture and it takes you to the photobucket site for the pitcher show.
You can see the piece of angle aluminum I used for an upper frame. That needs to be longer so the 'footprint' is spread out a bit.
The Lower wheels are on a pair of Disk brake pads. I'd make a piece of aluminum or steel shaped in a triangle with the lower wheels exactly between the uppers. That way the seat wont jam as it goes from back to front and vice versa.
If I remember to sit upright in the middle of the seat it works perfectly.
And I can lean way back in this one to relax as I have my coffee between fish.

 

You Should Check your PMs

 

your right! I oughta wake up!
I see what you mean by 'Rocker' now. I was thinking side to side. Your Rocker is OK, that'll work.
I can row like a machine. I row all day long when I go fishing. Even if its a bit stubborn, it's no worse that some of the Rafts and scows I've rowed.
Thiis looks good. Inside the boat is where the changes are gonna be made.