Newbie is building a river cruiser.....

Looks beautiful in natural wood, too bad they have to paint them (the hull anyway).

http://www.duckworksmagazine.com/05/projects/skiffamerica2/index.cfm


http://www.skiffamerica20.com/

NOTE: If it were my project just putting a cabin on a stock hull and getting it to balance would be challenge enough.

Example:
http://www.dixdesign.com/20fish.htm

 

Kilburn designed the boat with a 3/4" hook to the aft run (told me so himself)...that thing transitions from displacement to planning and you can never really tell when. You get almost no nose lift...perhaps at the expense of a knot or two because of the added resistance of the hook but they sure do cruise nicely. I don't know how much they might pound in a chop tho.

Steve

 

Really nice and practical! And weighing only 500 pounds empty.
http://www.boat-links.com/PT/PT2004/Sacagawea-1.jpg

 

The design first posted is retro futuristic and pretty cool looking. Before just throwing in the towel and convincing yourself it will not work, give it a try. Give it a try in RC model form.

If everything that's been said becomes apparent and true, then I still have one more suggestion. Floats or outriggers to keep the bow up and shift the center of lift. I think a Tri-hull look would work with the character of this design very well.

I also think hull drag on a non-tappered rear hull section will be the second major issue to be addressed (pointy bow is first). Whereas air would just rip off and form a vortex, water gets sucked in more which is why you never want to take a very small boat right along side a much larger ship at any speed. You will just get sucked in and under, this condition is worse at the stern. Hence the term "displacement craft" is applied to boats even while they are on plane.

 

I feel a bit guilty, we kind of hijacked this thread with the SkiffAmerica, nice boat but very different from the design posted...

 

Don't feel bad, if it does not work we all did him a huge favor. This is however a "Boat Design" forum and simply grabing plans off a shelf is not why I read the threads here. And I'm sure it's not why people post their forward thinking plans.

I'll say it time and time again, I'm not a "true" boat guy which is why I learn so much from everyone. I will try to pass on what I learn, so if Newinertia would please read the following article, I would enjoy discussing what I think it means and how it may apply to his design.

Marine Firefighting Inc.
Newsletter # 17
Maneuvering a Fireboat or Small Service Vessel Near Large Ships
http://www.marinefirefighting.com/Pages/Newsletters/Newsletter17.htm

 

OK, back to start.
The 20 (or 18?) feet x 4 feet flat bottom will work OK in flat water.
25HP/ton (total weight) may give 20 knots and burn 2 gallons (8 liter?) per hour.
If you manage to keep the weight down to 1100 pounds (half a ton) you can travel at 20 knots and burn 1 gallon per hour.

The bottom has an estimated area of 18 x 4 x 0.7 = 60 square feet.
With almost vertical sides and 1 feet draft that is 60 cubic feet, or 3600 pounds, so the boat will float high, no problems with that.
I am not used to feet and pounds, but it seems OK.

Materials and looks are persona taste

 

I found two "wedge-like" concepts in a gallery. More complex than the proposal in this thread (pg-1), yet somehow there is a kind of common link.

http://www.boatdesign.net/gallery/showphoto.php/photo/7680/cat/500/ppuser/18918

http://www.boatdesign.net/gallery/showphoto.php/photo/7670/cat/500/ppuser/18918

Of course these are not "real" boats, but they look to be a more workable starting point.

 

I was wondering if you can remove a thread- I have not gained any valuable information from your OPINIONS. I have posted a rudimentary sketch of a variant of the Bolger Sneakeasy and you people are so wrapped up in your own heads you have only discuraged me from even reading this site anymore. Just as no two people ever read the same book, no two people imagine the same perfect boat. I have completed the copyright trademark and trade dress for this hull design and am proceding with construction.
I highly suggest that you students dont necessarily take these GEEZERS advice on boat building as the gospel, a bit of common sense goes a long way. Materials have changed, methods of construction have changed, and these "senior members" are stuck in a rut.
As Jesse James of West coast choppers says,
"F*#K THE ESTABLISHMENT!"

 

1. Perhaps you will discover the value at a later stage, much like a parent's or older sibling's advice.

2. The Bolger Sneakeasy has near parallel sides for much of it's hull, this is not what you posted.

3. Jesse James is an poor leader, I saw when he tried to build a hovercraft from a Delorean, very very sad.

4. Learn from the mistakes of others, because you can't live long enough to make them all yourself.

5. My last suggestion was to keep wedge look for the upper deck, the hull below to be more conventional, and you still may have to add an outrigger to keep the bow up. It may not be a suggestion useful to a closed mind. I will post this picture as it may help communicate the idea to others. It may be a silly idea, but ideas can be changed more easily than metal hulls. Just pretend there is no sail, not quite literal.

http://www.multihulldesigns.com/stock/37tricmp.html

 

Newbie, welcome (from another novice) to the forum if you are still here.
This forum is like a crab fishery.
Put out your junk in a pot, see what attention it attracts.
Some jimmies, some mud toads, some eels, unlucky small fry.... Big claws pinch hard, but give a lot of meat. Just try to avoid the teeth and posionous spines.

There is a lot of knowledge here, but the style can get a little rude. Each forum has its own style... I keep coming back because many members have serious knowledge and experience that they often will share. If some want to pontificate a little, ignore it. You might not like it, but they have in some sense earned the right to mouth off.
My only problem with threads like this is that people tend to shoot both advanced concepts and harsh words back and forth without just explaining something very simple that could really be helpful.

So here is my attempt to say something helpful:
I'm an amateur, but I have seen lots of boats and the drawing in your post looks too skinny, and not curvy enough. It seems other members think this too, and they know more about boats than I.
I would try to make something like this about a foot wider. A wider transom will reduce tenderness and support engine weight. I think it needs to carry some width forward too so the bow won't dig in and you can walk around on gunwales and foredeck w/o tipping too much.

That freeship program really is pretty cool. So cool, I took an hour just for kicks and morphed a skiff form I had already made into a guess at the lines your illustration might represent, then modified it to be wider as above.Pic attached, not to be mistaken for a real plan!
If you want people to be able to offer advice on shape, it helps if you give 'em the conventional lines drawing format. I think a lot of criticism came because the drawing you put up suggested weird things about your design's shape -maybe good and distinctive things- but did not answer how they would be reconciled with the requirements of carrying a load, handling sea condition, etc. Or not. Just my thoughts.... Good luck

 

Nice drawing, it really communicates the design intent and I can see how it's a development along the lines of the design which started this thread.

I think what Newbie might be stuck crossing on is that his drawing is a concept, call it Industrial Design and not a finished product having been engineered.

A good discussion on this was in a thread in another forum.

Link:
http://forums.pelicanparts.com/show...e=20&highlight=industrial design&pagenumber=1

A couple of good quotes:

Hurra912

Another good one, but longer:

MFAFF

Knowing the term Prototyping should come in handy as well.
http://en.wikipedia.org/wiki/Prototyping

 

Skip,

Just in case you're still looking:

1. Your initial response to Tom Lathrop's comments on your design goals was words to the effect of, "Thanks for the feedback, I appreciate the constructive criticism". The next morning you deteriorated to, "Don't ever talk to me EVER AGAIN, I can't believe you said that." Somewhat later, you told everyone who tried to engage you in discussion to kiss off, ending with the very constructive, "F__k the establishment!" If you are serious about building a boat, I suggest you take a long look at your own succession of posts and ask yourself, "If that were the guy who was going to build my boat, would I be comfortable entrusting my own safety and that of my loved ones to his judgement?"

2. Tom was direct, not nasty. His estimates of performance, based on the hull and motor data you gave, may have been conservative, but that is a healthy dose of realism, in contrast to the exaggeration and "optimistic" performance cited by too many designers and builders, even those who claim to be honest, anti-establishment types catering to the amateur builder. For example: In the sales piece (and that is exactly what it is, however folksy it sounds) for plans for IDAHO, one of the designs mentioned by others as being similar to yours, the designer claims a cruising speed of "14 knots (over 18 mph)". That claim would be true only if a knot was 1.3 mph, which is ludicrous. In fact, 14 knots converts to only 16 mph. At one point in the blurb he claims a top speed of 30 mph; later in the same text he says, "about 25 knots", which is only 28 mph. Also, 40 years in business has taught me that "about" in reference to speed almost always translates as, "not really, but close to, sorta kinda". In contrast, the folks here did not try to sell you a design, but gave you feedback to help you modify your own. Some was just basic math: 20 mpg x 2 gph = 40 mph. If your hull/motor can't cruise at 40 mph, your 2 gph burn rate won't yield 20 mpg. That's called a "fact", something which can be, or has been proven to be true. Facts really suck, I know, because they are true whether we like them or not.

3. You're free, of course, to reject all advice offered and pursue your dream on your own. But it helps to know what world you're in. The designers and NA's on this forum aren't the establishment. The small boat establishment is Bayliner and Searay, who have to make compromise designs that can be built and sold to tens of thousands of people, operating under all sorts of different circumstances, and turn a healthy profit. The guys here are pretty independent thinkers, with a demonstrated interest in helping those who ask, as long as they remain polite.

4. In response to your Jesse James quote, I offer the following from Billy Joel, "...and he's boring as hell, is the angry young man."

May you bring more good judgement to your project than you demonstrated here.

Charlie McAllister

 

What is wrong with a Thai Long boat?

 

Do you mean the type that operates with a very long shaft and a prop 1-2 meters behind the hull? I've never seen design or performance specs on one of those, but they seem to go reasonably fast. Do you know anything about typical engine power and fuel consumption?