My first attempt at boat design

[Daywalker]

So, I've always wanted to build a boat for the last several years. I have been thinking of designs in my head, but I finally put it down on paper. I kind of just started to draw, so thats why its kind of large.

What I am aiming to build is a small sailing dinghy maybe 10-15 ft long. This is just the hull, I have little idea on what to do for the rigging.

I was going to build it out of plywood, with bulkheads made out of two or three pieces of plywood glued together.

I better mention that what I would like is a very simple boat that would last a few summers that I could use to get used to sailing and boat building. I have no sail expirence, just motorboat.

here is a pretty priliminary drawing

[Daywalker]

alright, I've been looking at other designs and other topics and I think the beam's max point might be in a bad place. So I think I'll make the sides come off at 90 degree angles from the transom instead of angling out slightly like I had it.


I think I would keep the length the same just to make the bow area less blunt I guess would be a word.

I'm not sure about a daggerboard how big I would have to make it, or where to locate the mast.

P.S.: I should have mentioned this before, but this will be sailed on Lake Ontario. So, it needs to be moderately sturdy. The lake can be a harsh mistress at times.

[JohnBloch]

Use Mariene grade Plywood... No gaps, thinner ply's to make a stronger and heavyer material... useable for mariene applications...

If you use that stuff... and keep it out of the water when you dont use it, it will probably last substantially longer than a year or two....

[yipster]

why dont you bend the plywood and make it look like a boat, freeship can easely draw the templates

[JohnBloch]

hey.. um... I downloaded freeship... and I cant get it to like... instal... I hate to jack the thread... but please pm me if you can help...

[yipster]

under tools check devellop plates ( version 1.8 ) give it a try, its a great program and please use the search button above for more discussion on freesch!p while i'll be downloading the newer version

[Daywalker]

are there any free ship tutorials on the forum because I've messed around with it, tried to read the manual, but it seems pretty complicated to me.

Does this mean there aren't any fatal design flaws that are obviously aparent? which I'll take as a plus

[sal's Dad]

Daywalker,

Your first boat really should be built to tried-and-true plans by an experienced designer; somebody with hundreds of designs under his (her?) belt. It is far easier to design an awful boat than a good one, and while noodling can be a lot of fun, too often home-designed boats are terrible disappointments.

Get a copy of Dynamite Payson's book, (or any of the dozens of others), pick out a small, simple plywood dinghy, and pound it together in a weekend or two. Then sail the boat. The experience you gain will be repaid MANY times over when you go to design/build another.

Whatever you do, don't do anything that might be percieved as "unusual" or "radical" in your first boat. Save that for your second, third...

Sal's Dad

[frosh]

Hi Daywalker, you can't assume that because a couple of guys posting havn't yet told you in plain English that your design is seriously flawed that it isn't. You are one of a regular stream of people that turn up on the forum claiming that they have no experience with boats (or sailboats) and posting a drawing of what they intend to build. There is another thread currently in this section about building a 9" sailboat. (His error, not mine) (same story).
Have a look at this flat bottomed skiff by CLC boats to see what your design should look like.
This is available as a kit boat where you assemble and glue and paint etc yourself. But for little more money you get a proven design and all the materials, with no waste and good instructions. This is definitely the way to go when you don't have a lot of experience.
You might not believe that in the end this will be more rewarding and cheaper than your first option of DIY from scratch. :)
http://www.clcboats.com/boats/skiff_lld.php

[SeaSpark]

Link to tutorial for freeship in "forum format" it started as an autocad question but develops into a nice tutorial.

http://www.woodenboat-ubb.com/vbulletin/upload/showthread.php?t=51018

There are many good reasons for a person with your amount of experiece to use existing plans. If you find making you own plans is very rewarding, study some more and go for it. You are trying to start small which is a good thing. I agree with other forum members that you are starting too small, add a couple of feet (and round side panels) your boat will be much more useable and still will not be very expencive or labour intensive.

[Daywalker]

so you guys probably are right about using someone elses plans. I found this.

http://www.svensons.com/boat/?p=SailBoats/Zephyr

its on a website with other plans, but I think it is pretty much what I wanted. It says it was designed for the rough waters of the English Channel, so it should be able to handle Lake Ontario.

[yipster]

that makes sense, still when looking at forexample the covex bottom and stem of above and a sharpie ( planty free plans around ) i'd go sharpie (http://freepages.genealogy.rootsweb.com/~fassitt/cranks/9ft_Sharpie.html)...
with bottom boards not the lose planks with cotton in between as illustrated here
http://freepages.genealogy.rootsweb.com/~fassitt/cranks/11.gif

[frosh]

Hi Daywalker, I would go with a flat bottom sharpie as your first project.
That zephyr boat is quite involved and would take three times as long to build and a lot more skills which you have not yet developed. :)

[Daywalker]

fair enough, I just want something that can handle the lake and I can learn about sails and rigging, so whatever will get me out on the lake.

thanks to all for pointing me in the right direction, it is much appreciated:D


Is there any information on how to turn that design into a sailing dinghy?

[frosh]

Hi Daywalker, the diagram posted by Yipster is for a very old fashioned construction, now virtually obsolete unless you are making a replica of an antique boat. I refer you back to an earlier posting of mine, to the link to CLC boats that I gave you, for a sailing sharpie of simple construction. :)

[lewisboats]

Why not do up a PDRacer? You can be on the water next week.

Steve

[Daywalker]

Would a PD Racer be able to handle Lake Ontario? I thought they were for pretty calm waters, like ponds and small lakes.

[frosh]

Hi Daywalker, I have just posted a reply to John Bloch who is looking for a first time wood sailing boat project. This is what I suggested, plans are $35 for an 11 foot boat that can sail with one or two aboard. Importantly it will handle a bit of rough water as it has a pointy bow and good size freeboard. Most important it is quick to build and requires minimal skills. See this site:
http://www.boatplans-online.com/proddetail.php?prod=SD11 :)

[byankee]

daywalker -

Check out the following websites and plans. You may find something you like. They're all supposed to be suitable for beginner boat builders.

Jaques Mertens:

V12 - Vee Bottom Dingy - http://www.boatplans-online.com/proddetail.php?prod=V12

C12 - 12' Cat Boat - http://www.boatplans-online.com/proddetail.php?prod=C12

SD11 - Semi Dory 11 - http://www.boatplans-online.com/proddetail.php?prod=SD11


Chesepeak Light Craft:

13' 2" Jimmy Skiff - http://www.clcboats.com/boats/skiff.php

Chesepeake Marine Design:
Bay Skiff 12 - http://www.cmdboats.com/bayskiff.htm?cart_id=389acc3aac33327bb3085dd87acd064f

Sailing Skiff 15 - http://www.cmdboats.com/sailingskiff15.htm?cart_id=389acc3aac33327bb3085dd87acd064f (I have these plans. The boat should be very easy to build)

Steve Redmond:
Bluegill 15' sail & outboard skiff - http://www.sredmond.com/index_boat.htm
(again, I have these plans. It's not stitch and glue construction, but it should be very easy to build)

Phil Bolger:
Teal - http://www.instantboats.com/teal.htm ( 12 footer - very popular/proven design)

Cartopper - http://www.instantboats.com/cartopper.htm (11 footer - again a popular and proven design that's easy to build)

Jim Michalak: (a bit of an aquired taste, perhaps, but he's got good reasoning behind his designs. The use of leeboards frees up interior space in the boat - something to serioulsy consider in such a small craft):

Mixer - http://www.duckworksbbs.com/plans/jim/mixer/index.htm

Piccup Pram - http://www.duckworksbbs.com/plans/ji...pram/index.htm


That ought to keep you busy for a while....;)

About boat design software: Try Hull Designer (free download at http://www.carlsondesign.com/#Fun_Shareware ). This one's much easier to figure out and use than freeship and may be all that you need for now. You can import files from this program into Freeship if you want to create linesplans, see what th eboat looks like in different colors, etc.

[Daywalker]

that bay skiff 12' looks pretty nice, or maybe the Jimmy Skiff. These boats can get up to a pretty good clip right? I'm not talking about as fast a racer, but enough to keep it interesting.

I figure I'll make a PD racer to mess around with this summer, and build either the bayskiff or jimmy skiff during the winter. That way I won't be in a rush to get on the water and hopefully avoid any frustration or mistakes caused by hast. I'll also have made atleast one "boat" before I start on something nice.


all of you have really be helpful, thank you.

[JohnBloch]

that bay skiff 12' looks pretty nice, or maybe the Jimmy Skiff. These boats can get up to a pretty good clip right? I'm not talking about as fast a racer, but enough to keep it interesting.

I figure I'll make a PD racer to mess around with this summer, and build either the bayskiff or jimmy skiff during the winter. That way I won't be in a rush to get on the water and hopefully avoid any frustration or mistakes caused by hast. I'll also have made atleast one "boat" before I start on something nice.


all of you have really be helpful, thank you.


yeah.. after looking through all the designs posted in my thread, the bay skiff 12 was what was decided on... except Im going to try and hit it with no experiance... we'll see how it goes...

the measure 8 times, and cut once method will be employed...

[BOATMIK]

Hi Daywalker,
Importantly it will handle a bit of rough water as it has a pointy bow and good size freeboard.

Er - pointy bow has been historically shown to make little or no difference to seaworthiness. So why you say ...

Oh - I see - er - splits the waves cleanly.

There are hundreds of years of boating tradition involved in bluff bowed boats. some of them very fine seaboats indeed - from Dutch Yachts to Cook's Endeavour. Even a flat nosed scow can handle rough water very nicely indeed and at high speed.

in more modern terms American scow classes, Australian scow moths. And we get lots of strong wind and a nasty chop on our harbours and lakes in Australia and the scow moths handled them fine.

Best wishes to all
MIK

[BOATMIK]

Why not do up a PDRacer? You can be on the water next week.

Steve

Good choice!!!!!!!!!!!1

And it allows you some opportunity to design your own rigs, foil configuration and components.

http://www.pdracer.com

http://members.ozemail.com.au/~storerm/Pdr/pdracer2boatmiddist.jpg

Building thread
http://www.woodworkforums.ubeaut.com.au/showthread.php?t=28107

Sailing Videos and other bumph
http://members.ozemail.com.au/~storerm/Pdr/pdr.html

It is cheap and carries two adults easily.

Class racing developing - we are only 2 years old!!!

Best Regards to all

Michael

[frosh]

Hi Boatmik, Daywalker has already indicated that he intends to build a PD racer as his first project, and we are all comfortable with that, as it an excellent way to learn the art of boatbuilding.
As far as having the opportunity to design almost everything except the lower part of the hull is a distinct disadvantage in this case.
You need to have a greater understanding than what he has thus far to do this tricky part well. If the designs were restricted and detailed in a plan it would be far better.
The only advantage of the PD is the learning process, I think that unless you are less than 8 or over 70 it would by bloody boring to sail in the extreme.
Even a Laser is far more interesting to sail or race, and this is considered very tame by the standards of modern singlehanders.
Re the bluff bowed sailing ships you refer to and their seaworthiness, I have no argument.
It is only that if your local waters are choppy and windy, my idea is that a very small dinghy would handle it better if skiff shaped, rather than pram bowed. Scows such as Moths are a bit different to a PD racer in shape!

[BOATMIK]

Hi Boatmik, Daywalker has already indicated that he intends to build a PD racer as his first project, and we are all comfortable with that, as it an excellent way to learn the art of boatbuilding.
As far as having the opportunity to design almost everything except the lower part of the hull is a distinct disadvantage in this case.
You need to have a greater understanding than what he has thus far to do this tricky part well. If the designs were restricted and detailed in a plan it would be far better..

I can give him all that information at this point.

We have (in Australia) been developing a platform structure, rig and foilset that makes the boats go quite well. Hull comes in at around 60lbs out of 3 sheets of ply - there is 80 odd square feet of sail on a bendy, hollow, easy to build (and light) timber mast to make it work through the wind range.

Daywalker you can contact me on storerm@ozemail.com.au for the drawings at this stage - if you want. I am still working on the full assembly instructions but the drawings are basically done. I am a full time designer so the information is fully detailed. You are welcome to use them as a starting point to start your own explorations.

I have beefed the mast up a little since building the first two boats as if you looked at it in the videos on the above site it was bending a little too much upwind in the stronger wind range.

Boat sails well on all points and recovers from capsize well too - see videos. Have a careful look at the light wind footage - 80 square feet moves a boat with this little wetted surface along really well in around 6/7 knots of breeze.

The planing shots were a bit pitiful because the wind was patchy on the river and we only had a clear run for about 150ft. The PDR won't plane like a 505 - but it will plane (and it will probably take more skill to sustain it than the boats you are talking about Frosh.)

The only advantage of the PD is the learning process, I think that unless you are less than 8 or over 70 it would by bloody boring to sail in the extreme.
Even a Laser is far more interesting to sail or race, and this is considered very tame by the standards of modern singlehanders.

But that attitude is why small boat sailing has died in the bum over the last 30 years. It was HUGE in the 70s while the boats were of a technology that enabled people to build their own boat - but since then has been in a dramatic decline.

Performance at all cost has been the problem. In these parts it costs between $4000 (Optimist) and $7,000 (Manly Junior - an 8ft Sydney dinghy for 2) to get a kid/s on the water - because of foam glass hulls, spun tapered masts, NC routed foils and mylar sails.

For a "real" performance dinghy - expect to spend more money than many people will spend on a car.

Many of the worst offenders have been boats that were set up to be "easy entry level boats for dad and the kids to put together" or "high performance at low cost" - just like the two above.

I agree that not everyone wants to sail a PD Racer - but it is exactly the class that is needed to bring a whole lot of people into small boat sailing that are currently excluded because of the complication and expense of the boats.

Later on some will move to more "interesting" boats - but I suspect a large number will stay with the PD Racer.

Much like people stay with the Star, OK, Heron, National 12 or whatever - not fast boats in their size or type. Pure performance doesn't appeal to MOST people in the sailing scene. Otherwise we would all be sailing Moths, 18ft skiffs and A-class cats.

As far as performance goes - I bet you can't design and build a PDR that can beat ours for the same money :-)

$300 Australian per boat - with some scavenged solid timber for laminating up the foils and for cleats (the structural type - to hold the ply bits of the hull together).

Anyway - this is very close to hijacking the thread - but I think it is important to realise that any boat that works well is a good boat - and valid in design terms - because it is the quality of the thinking behind the design that makes it worthwhile. The PDR shouldn't be discounted because its performance is "less" than other boats that are around.

Best Regards to All
Michael Storer

[frosh]

Hi Michael, There are some very sound ideas in your posting and on the whole I must agree.
One of the tragedies of sailing for the average person in Australia over our lifetimes is well stated by you, but I think that the PD takes the simplicity thing just a bit too far.
"But that attitude is why small boat sailing has died in the bum over the last 30 years. It was HUGE in the 70s while the boats were of a technology that enabled people to build their own boat - but since then has been in a dramatic decline".

What adult would have chosen to sail in a Sabot in the 70's when alternatives for the home builder with limited money were plentiful?
Do you recollect the Rainbow Scow, Sailfish (sailing surfboard style) just for starters? Then Aussie scow Moths were easy and cheap to build, and there were large fleets in all states.

Would it not have been also reasonable to go with a design similar to the Mark 2 scow Moth as a wood home built revival class for the masses? :)

[BOATMIK]

Hi Frosh,

I agree completely with the sorts of boats that you are talking about - but all these classes are now either expensive for the above reasons (victims of the sailing arms race) - or defunct because they were too limited in use.

BTW did you have a look at the videos of our OZ version PDRs?
http://members.ozemail.com.au/~storerm/Pdr/pdr.html
We have made them sail quite well. I suspect that they would whop the El Toro's shown earlier in this thread - our boats REALLY move in light winds (86sq ft of sail on an 8ft boat moves it along quite nicely) and the mast/sail combo keeps them easy to handle as the wind comes up. They even have a sheerline!

http://members.ozemail.com.au/~storerm/Pdr/vidthumb2pdrupwind.jpg

The reason that I decided to spend a fair bit of design and building effort on the PDR rather than start from scratch is

1/ The class is already growing very quickly - with over 100 registered boats after two years and a boat or two (sometimes 10) being registered each week.

2/ It is also attracting people who have never done much sailing - and that is simultaneously their biggest advantage and biggest downfall. Not that it matters too much for the people who have built them - and at least they are working it out themselves rather than accepting some sort of prepackaged solution.

3/ The up side is an enthusiasm for boats and boating that I haven't seen in average people for years and years and the pressure they are exerting to keep things cheap rather than enter the conventional sailing "arms race".

The downside is as you rightly point out - that a lot of the boats have not worked particularly well. Which leads to ...

4/ The design challenge of making a very basic boat work really well - Which is what interested me as far as stepping in and working out a boat using the same (or less) material, that would be light enough for a couple of kids to carry, would avoid expensive parts and sail as well as possible.

My feeling about design is that you can get almost anything to sail well if you get the rig and appendages right - so our starting point was to work out how to do it with the materials that are currently in use within the class - just using more of the knowledge that is around for building wooden boats with good performance - the great OZ tradition of more sail and light, efficient structures

5/ They can carry a big payload. The other advantage of the PDRs - and the other main reasons why people like them is that they can carry two adults - and our big sails result in them still sailing fine with that weight in light or heavy wind - upwind and down

http://members.ozemail.com.au/~storerm/Pdr/pdracercoverpic.jpg

6/ And perhaps a bit more on the marketing front - women and children think they are really cute - actually - everyone reckons they look pretty cute and are usually dying to go for a sail. They are completely unintimidating.

7/ Their simplicity and cheapness makes them non-precious - the sort of boat that you can lend to the neighbours kids without worrying about damage to the boat or them getting into too much trouble.

And I am getting plans ready over the next few weeks - they are almost done but its all the final details that suck the time. We will be making the plans really cheap - less than $20 for direct download but in this case they well be well detailed with a full set of step by step instructions - better than most plans that are around - even ones that you pay quite a lot for (properly detailed plans have always been one of my specialties). Maybe I will break even?

Best Regards
Michael

[frosh]

Hi Michael, I have had a chance to look at the video and website and can see the validity of the concept. It wouldnt appeal to me as I have sailed higher performance boats for a long time. But for first timers or people coming back after a very long absence it is almost ideal.
Notice I said almost as the original designer could have have easily done a little better without much change in cost or degree of difficulty.
However I understand that you have wisely or safely supported an already established class, and it has the distinction of being the easiest and cheapest to get ready for the water.
Congratulations! and good work to provide really cheap plans to everyone. :)

[lewisboats]

The original 'designer' is an amateur designer who wanted to something simple and inexpensive to build. Shorty hit upon exactly what he was looking for and it has been highly successful...beyond his dreams really. Never asked a penny for it either. What a lot of people find fun about them (whether it is safe or not) is that they can fiddle with the topsides to their heart's content and still be in the class because only the underwater parts need conform to the rules. I've heard of one with a cannon??? and maybe a castle or two (for and aft)?!!!
Wouldn't win any races but sure would get the kids interested in sailing.

Steve

[BOATMIK]

Put together the stability - allowing the boat to carry heaps of sail. 86sq ft on ours

With the low wetted surface - short and lots of rocker

And you have a demonic light wind package.

I think there is a good chance in the right conditions :-)

and none of it would have been possible without Shorty (www.pdracer.com) working out a way to have class racing (which is FUN) at little expense.

MIK

[ernie]

Defiantly go with the sharpie, do a search for Phil Bolger, he has many examples of what can be done with a sharpie.

I do admire and understand the draw of designing your own boat, but wait till you have the sailing skill to know if a flaw is the boat or the driver.
Once you start building your own designs, you will learn quickly what curves do what, and what is easy to build.

I have been looking at the PD racer, very cool, I will be building one of two soon.


Also as a thought, wouldn’t be in spec for the class, but what would you get if you applied the same curve to the hull sides, to make the for and aft transoms slightly narrower. How would this affect the performance? This would be for a personal dingy, not a class boat.

[frosh]

Hi Ernie, The reason for the straight sides was building simplicity and to build class numbers quickly as a result. In flat water and medium winds the original shape might be better, however in light winds or choppy conditions I believe that pulled in bow and stern transoms would be superior.
In light weather the surface area of the hull bottom is quite large and would be faster if the hull was heeled to leeward. With the class legal shape the immersed section becomes a shocker if it becomes heeled!
In choppy conditions the massive bow transom would be getting hit by solid water considerably, with obvious effect. Wetted surface at the stern of the amount in the class legal shape is excessive and also the stern transom will often be partly immersed, being very draggy, so the width if less, will correspondingly drag less.
However I think that the hull is too short for an adult as well, but was conceived so the bottom is a simple single sheet of ply with no cutting or joining required. :)

[ernie]

Im thinking of keeping the same curve as the bottom and applying it to the sides.
This should follow Bolgers rule of having the same curve.

another question, would a Brick qualify as a PD? is the curve the same? I will also ask on the duck board.(answered elswhere - NO- thanks)

[BOATMIK]

New website for PD Racers
http://www.pdracer.info

[BOATMIK]

Notwithstanding what has been said above - here are some videos of a PDRacer sailing. Taken since this discussion.

http://www.youtube.com/profile_videos?user=bitingmidge

It sails fine with an adult weight aboard as you can see. Since I wrote the above post we've had them out in 25kn a couple of times - still handle reliably and go upwind fine including a chop.

http://www.pdracer.com/records/speed/mik/dd4.jpg

Not the fastest kids on the block - but a very acceptable starting point. As frosh points out it would have resulted in more performance to change the basic concept - to get a little more speed. And it would have been only a little more speed for lots of messing around.

However one thing we have found is the box shape gives so much stability that you can carry very big rigs. With a good mast/sail combo the more experienced sailors are carrying 82 to 86 square feet.

And the rigs don't need to cost much as the polytarp sails cost around $50 a pop. The blue one you see on the orange boat in the videos is 3 years old with around 60 days sailing under its belt.

The yellow boat above cost $350 to get on the water.

Best wishes
Boatmik

[rwatson]

Frosh - you are right, thats a really nice design, and no harder to build really. And it probably has things like measurements, material lists etc

I think its worth having a look Daywalker, - I would commend the design as a great first project.