questions from an hobby boat designer

Discussion in 'Boat Design' started by gunship, Dec 21, 2009.

  1. gunship
    Joined: Jun 2009
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    Location: Sweden

    gunship Senior Member

    hello. im a 17 year old student, and i like to design boats, purley for hobby purposes, been doing it since before i could write - prbably something my naval architect grandpah got me to do.

    so, now that my designs take a more serious approach, i have a few questions about the boat designing stuff. i have some questions of the less obvious things that you doesent think of untill you're drawing it with a ruler...

    first: what height over deck do you usually have the boom on? i suspect around 160-170cm? (boom is not over a cabin, just plain deck)

    what width is the (for boats) usual space for walking 'paths' for say a midship corridor?

    how secure are windows approx 40x60cm?

    what freeboard is required for say crossing the atlantic?
     
  2. yipster
    Joined: Oct 2002
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    Location: netherlands

    yipster designer

    and many more questions are discussed on this here forum and you can use the search button above without using google
    give delftship a good try for drawing and have a look in the free database to see other and compare your designs
     
  3. alan white
    Joined: Mar 2007
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    Location: maine

    alan white Senior Member

    There are a few considerations for boom height. "As high as you must" on bigger boats with potentially lethal boom weights, meaning above your head if possible, especially at the boom's end, and in smaller boats with less lethal booms, high enough to duck comfortably. Ideally, for performance, the boom would sweep the deck, but we can't have that. The question of boom height is, therefore, entirely a matter of human ergonomics.
    The space between seats in a cockpit can be narrower if shallower, but deep aisles need to be wider to allow standing when heeled without interference. A comfortable width is 2 ft., but there are no hard and fast rules.
     
  4. gunship
    Joined: Jun 2009
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    Location: Sweden

    gunship Senior Member

    thanks for the answers.

    good thing about the boom and seats. never thought of the heeling for the steeiring wheel _inside_ the cockpit, just for the dual weels outside.

    and about the boom height, won't it be hard to reef if its above your head? i have only sailed small boats, so i have no experience myself.
     
  5. capt vimes
    Joined: Apr 2009
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    Location: Austria

    capt vimes Senior Member

    depending on the reefing system....

    usually you will have reeflines already attached to the main and the lines are brought back to the cockpit from where they are dealt with...
    one has nevertheless go forward and bind the loose sail together around the boom in a way to prevent it from flapping around but for that you are standing on the deck of the topsides and at this elevated postion the boom comes up to about breast to headhight... easy to work from there...
     

  6. dreamer
    Joined: Nov 2004
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    Location: Minnesota, USA

    dreamer Soñadora

    We had a Capri 22 with the boom about 20 cm over the cabin (previous owner cut the sail extra large). Tacking required a great deal of attention. There was more than one head smacked by that boom. Luckily, it was usually on a close haul so the boom didn't have a lot of momentum. Just enough to make people pay attention.

    If your boat is small, as Alan mentioned the boom can be just high enough to duck under. You will have no problem standing up to reef. Otherwise, consider that when you're reefing, you'll be able to drop the boom to do so. If you have an enclosed deck (not a fully open boat), the boom can be over your head while standing in the cockpit, but easily reachable by standing on deck.
     
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