help need with first design

Discussion in 'Boat Design' started by chadwick79, Nov 30, 2010.

  1. chadwick79
    Joined: Nov 2010
    Posts: 6
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: hull

    chadwick79 Junior Member

    i am just about to embark on one of the most exciting project. i want to design and build our own yacht. i terms of experience when i left school i trained as an engineer and for the last 20 years i have been building houses in the UK.

    so i am able to weld although I'm a little rusty
    fix and maintain engines.
    very good to wood of almost any kind although spent most of my working life work with pine and oak.

    i think i want to build a steel hull.

    the type of boat i want to build is a single hull cruise yacht it must beable to sleep myself wife and 5 children. i want to be able to power to yacht by both diesel and sail.

    in terms of space to build the i own a builder yard with a 10,000 sqf shed on the site

    as to my questions:

    is there an overall length to beam ratio that one keeps to when designing.
    is the a perfect angle front nose should be (sorry if i'm not using the correct terms as i still learning them)
    is there a hight beam length ratio to be taken into account when think of the keel.

    i would also be greatful to any advice you can give me thanks for reading. i look forward to read the responses
     
  2. michael pierzga
    Joined: Dec 2008
    Posts: 4,862
    Likes: 116, Points: 0, Legacy Rep: 1180
    Location: spain

    michael pierzga Senior Member

    The problem is your question is so big and the possible answers so vast that you would never get off the ground !!!!!!!!!!!

    This is a study plan for a sailboat. They are called STUDY plans so that interested engineers like yourself can study and understand the concept . Boats are very simple things and very complex...teams of Pros's are spending their whole careers perfecting Beam to length ratios and construction techniques. .


    www.dhylanboats.com/plans/coquina_study_plans.pdf]

    www.dhylanboats.com/plans/top_hat_study_plans.pdf


    These study plans are available for a huge variety of different boat types. Pick a style you like, then begin designing it in your own hand, then propose optimizing input.

    Be sure to pick study plans from high class naval architects because they will already be 99.9 percent perfect and only need your special input and skill to bring it to your task.
     
  3. kerosene
    Joined: Jul 2006
    Posts: 1,285
    Likes: 203, Points: 63, Legacy Rep: 358
    Location: finland

    kerosene Senior Member

    judging from your questions yacht design is new to you. I recommend strongly you pick an existing proven design.

    Its not a bad idea to educate yourself about yacht design even if buying plans - helps you pick plans better. It is important to understand that most decisions are compromises - to gain something you lose something.

    Nobody can give you a beam to length ration that works "best" or tell how fine the entry (how pointy the nose is) should be. Those things are part of much more complicated dilemma that is yacht design.

    Don't put insane amount of work on a boat that sails like crap and is dangerous because you insist on designing it yourself. !2 foot dinghy can be approached like that if good sense is used but not something big where the stakes (lives, time and money) are so much higher.

    H

    search for book lists on this site - they have been posted over and over again.
     
  4. gonzo
    Joined: Aug 2002
    Posts: 16,790
    Likes: 1,714, Points: 123, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    My advice is to take your wife and kids sailing for a week or so in a rented boat. That may be the end of your project. If you all decide to go ahead, it will at least give everyone an idea of what sailing involves. The questions you are asking are intelligent, but so basic, that there is no real good answer. You need to study basic of boat design to be able to narrow them. Also, get time at sea, all of you, to make an educated decision.
     
  5. ancient kayaker
    Joined: Aug 2006
    Posts: 3,497
    Likes: 147, Points: 0, Legacy Rep: 2291
    Location: Alliston, Ontario, Canada

    ancient kayaker aka Terry Haines

    I regretfully have to join the others in discouraging you.

    Yacht designers study for years to do this. You sound much better qualified to design your own car. Would you do that, and trust your family to the vehicle? I suspect not. Here are some of the additional risks a well-designed and built yacht offers you that will not be encountered in even an incompetently home-built road vehicle:

    death by drowning (sinking, collision at sea, falling overboard etc)
    death by explosion of fuel or propane
    death or injury by falling tackle from the masthead
    death or injury by being struck by the boom
    death from thirst or starvation at sea resulting from capsize, lost of sailing rig, out of fuel etc.

    I like choice as much as the next person, but not when it comes to my death - I prefer that to come as a surprise after a bit more time ...

    A purchased design is a mere fraction of the cost of building any boat, and will ensure that your considerable investment in time and materials will have some chance of a return, in the form of a valuable vessel that will keep your family safe and dry.

    If you are determined to do this, then remember as a general rule, someone who wishes to undertake an outstanding endeavour needs a little patience and should start small!
     
  6. PAR
    Joined: Nov 2003
    Posts: 19,126
    Likes: 498, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

  7. alan white
    Joined: Mar 2007
    Posts: 3,730
    Likes: 123, Points: 0, Legacy Rep: 1404
    Location: maine

    alan white Senior Member

    Yeah, it's not so simple designing your own yacht. I don't understand why so many people with very little knowledge of the art of boat design would attempt it. It IS like designing a car. And the bigger the boat, the bigger the risk.
    Even the best designers have done designs that didn't meet with their highest expectations. That's why people (and I mean people who COULD design their own boat) are much more likely to go with a known design, one that's circumnavigated or at least carried folks safely across big water.
    You can predict with reasonable accuracy how a boat will perform by building one that's very similar to an existing design. But then why do it? You could have built the existing design for far less effort just by buying a set of plans.
    You can certainly modify some things. Extend the cabin by a bit, rearrange the layout, change the rig if you're qualified to do so.
    The hull and rig's center of effort are the main thing. You can modify much of the rest of the boat to a degree.
    Just building a yacht is an enormous job, often taking several years to complete. It would be a tragedy to end up with a boat that won't sail well or one that has fundamental weaknesses in the construction.
     
  8. PAR
    Joined: Nov 2003
    Posts: 19,126
    Likes: 498, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    It's just as easy to build a boat that sails like crap or is imposable to live with as it is one that preforms above expectations, because it's a well engineered and thought out design. It's your choice . . .
     
  9. tom28571
    Joined: Dec 2001
    Posts: 2,474
    Likes: 117, Points: 63, Legacy Rep: 1728
    Location: Oriental, NC

    tom28571 Senior Member

    I am not going to discourage you but Gonzo's advice is very sound. If I had been discouraged from attempting to design my own boat, I, and some other builders, would have never have the very nice boat that we have enjoyed for many years. That said, it was several years of study before I felt competent enough to begin building on my first design. I started with an advanced engineering degree and many years of waterborne experience and designing and working with wood.

    After, or along with experience on the water, studying the basics is the first step toward some level of competence. Even then, most will not attempt a project as large and complicated as the one you plan. In fact, I don't think anyone should attempt such a task on their first boat. The good news is that the time spent in study and research is not lost time and is at least as rewarding as the actual building and use of the finished boat.
     
  10. chadwick79
    Joined: Nov 2010
    Posts: 6
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: hull

    chadwick79 Junior Member

    i did forget to say that the yacht is not only for myself and the family we are doing this to help children who like myself who have been either sexually physically or mentally abused. Once we have a design the children will get involved with everything from the laying out and bolts to the finishing touches. this is to help the children (teens) gain confidence. the youngest will be 10 and the oldest 17 they will come for all backgrounds but will all have one or two things in common with each other.
     
  11. gonzo
    Joined: Aug 2002
    Posts: 16,790
    Likes: 1,714, Points: 123, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    OK, so someone who doesn't know how to design a boat will have kids who don't know how to build one make it. It is a far fetched fantasy. How can they gain confidence with a project that has no hope of success? Maybe they can build skiffs or canoes and gain confidence. However, they will need an experienced person to guide them on the process. If you are experienced with cars, that would be a worthwhile project: rebuild cars.
     
  12. liki
    Joined: Nov 2008
    Posts: 221
    Likes: 12, Points: 18, Legacy Rep: 114
    Location: Finland

    liki Senior Member

    For a charity project you might also be able to find a professional designer willing to help "pro bono".
     
  13. michael pierzga
    Joined: Dec 2008
    Posts: 4,862
    Likes: 116, Points: 0, Legacy Rep: 1180
    Location: spain

    michael pierzga Senior Member

    Nice project Chadwick...best luck with it. Why not build a canal boat...a narrow boat. Non technical construction, steel or wood, plenty of work to keep young peoples hands busy and minds thinking plus once finished a great way for a group of young folks to cruise around and check things out.

    Some study plans from Selway are worth a look at.

    http://www.selway-fisher.com/Mcover30.htm
     
  14. daiquiri
    Joined: May 2004
    Posts: 5,371
    Likes: 258, Points: 93, Legacy Rep: 3380
    Location: Italy (Garda Lake) and Croatia (Istria)

    daiquiri Engineering and Design

    Chadwick, your intentions are noble - but they are too far-fetched. You risk giving those kids a big delusion instead of a joy of creating and sailing their own boat.
    All the advices given so far are perfectly valid and I share them fully. Two in particular, by Kerosene and by Gonzo:

    1) embark ona a sailboat and do some sailing before taking a final decision. Do a lots of sailing, if possible. It will teach you many things about what a sailboat is, why is it done that way, and what are the principal characteristics you should seek in a project of a sailboat. Try to go out in many different weather conditions, in order to learn how beautiful sailing is, but also how uncomfortable and sometimes scary it can become.

    2) size down your desire and look after a type of boat within your reach. It will be a great school project in boat design and boatbuilding for both you and the kids. You should aim at a small stitch-and-glue dinghy, as Kerosene suggested. If you manage to build one and you see that it was fun for you and your gang, then you can build another one, and another again. You could eventually end up with a small fleet of dinghies, which could be used to organize other social and sport activities for the kids - like regattas and group picnic trips to some nice nearby natural areas, for example.

    Cheers, and good luck with your project!
     

  15. MikeJohns
    Joined: Aug 2004
    Posts: 3,192
    Likes: 208, Points: 63, Legacy Rep: 2054
    Location: Australia

    MikeJohns Senior Member

    Pragmatically I'd say the first design of an amateur naval architect is usually a very poor one and it's a steep learning curve that usually involves being an understudy for a few years.

    You don't say if you have any experience operating or crewing on small vessels. It sounds like you don't.

    Experience teaches you a lot about the practical side.

    I'd recommend a little book by John Teale 'How to design a boat', it's simple enough to pick up and a good introduction to the sort of vessel you are talking of.

    But really your best approach is to get some plans of one of us and alter them in consultation to match your requirements.

    What can I say to encourage you:

    If it's steel hulled then for a start its a medium to heavy displacement vessel and your beam length ratio will depend on the overall length.

    I'd recommend a chine design it's much faster to build and doesn't compromise performance if designed properly. The proviso is that the chine must be sensibly placed. Model testing is worthwhile in this regard, and again you'll be better of with an existing design.

    The number of masts will depend on the length again.
    Underbody profile will be dictated by length and by draft restriction.

    Budget is the real crux, you have to be able to buy scavenge or make all the gear that changes a hull into a boat.

    So start with a full statement of operational requirements. Wrap the design around the requirements but please do it with some help or you will be disappointed.

    We built a large vessel here with down and out kids and it was a very successful project. If they all work the build can go very quickly there's usually a job for every level of ability, providing there's one experienced shipwright that can be called on every few days it can go surprisingly smoothly.
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.