Small Boat in cold climates

Discussion in 'Boat Design' started by wmonastra, Nov 20, 2007.

  1. Guillermo
    Joined: Mar 2005
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    Guillermo Ingeniero Naval

    Another aspect to take into consideration is the need of checking stability against the accretion of ice on boat and rig.

    As an example, here the exigencies for fishing vessels under The Code of Safe Working Practice for 15 m (LOA) to less than 24 m (L) Fishing Vessels

    "The icing-up allowance which represents the added weight due to ice accretion on the exposed surfaces of the hull, superstructure, deck, deckhouses and companionways should be calculated as follows:

    (i) full icing allowance:
    all exposed horizontal surfaces (decks, house tops, etc.) should be assumed to carry an ice weight of 30 kilogrammes per square metre.
    The projected lateral area of the vessel above the waterline (a silhouette) should be assumed to carry an ice weight of 15 kilogrammes per square metre. The height of the centre of gravity should be calculated according to the heights of the respective areas and in the case of the projected lateral area the effect of sundry booms, rails, wires, etc., which will not have been included in the area calculated should be taken into account by increasing by 5% the weight due to the lateral area and the moment of this weight by 10%.
    This allowance should apply in winter (1st November to 30th April inclusive in the northern hemisphere) to vessels which operate in the following areas:
    (a) the area north of latitude 66º30’N. between longitude 10ºW. and the Norwegian Coast;
    (b) the area north of latitude 63ºN. between longitude 28ºW. and 10ºW.;
    (c) the area north of latitude 45ºN. between the North American continent and longitude 28ºW.;
    (d) all sea areas north of the European, Asian and North American continents east and west of the areas defined in (a), (b) and (c) above;
    (e) Bering and Okhotsk seas and Tatar Strait;
    (f) South of latitude 60ºS.

    (ii) Half of the full icing allowance:
    this should be taken as one half of that calculated under sub-paragraph (i) of this paragraph and should apply in winter to vessels which operate in all areas north of latitude 61ºN. between longitude 28ºW. and the Norwegian Coast and south of the areas defined as the lower limit for the full icing allowance between longitude 28ºW. and the Norwegian Coast."


    Cheers.
     
  2. Guillermo
    Joined: Mar 2005
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    Guillermo Ingeniero Naval

    I'd say you should consider also to comply with some criteria for stability after damage, such as the one in the Code of Practice for Small Sailing Vessels:

    "4.4.1.2 In the damaged condition, the residual stability should be such that the angle of equilibrium does not exceed 7 degrees from the upright, the resulting righting lever curve has a range to the downflooding angle of at least 15 degrees beyond the angle of equilibrium, the maximum righting lever within that range is not less than 100mm and the area under the curve is not less than 0.015 metre radians."

    Cheers.

    P.S.
    You should check with your national authorities, to find out if they allow you at all to build up and sail the Poles in a 30' footer. I don't know what the rules and regulations are over there, but if they are similar to UK's MCA ones or the like, I have doubts a boat that size would qualify.
     
  3. enjoysurvival
    Joined: Nov 2007
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    enjoysurvival Junior Member

    survival

    Hi,

    Not splinking cold water on your face. You have to think about "enjoy survial kits (ESK)"

    You should have all the ultra extra necessary supplies besides electrionic devices.
    Think how to gurantee all stuff go with you if , in any case....it happens.

    I am renovating the concept of survival at sea. Most cases , once happens , they have only biscuits , rations .... . Why not a big meal in the primitive device ( life raft ) ? You should have a 4 person raft for one man , water proof low resolution camera ( are you to record all the next 5 years ?)

    Bring also spear gun and solar charger for mp3 and computer.
    Some may think using a computer in a life raft is crasy , but , why so disastrous in disater ?

    I am also designing a food and supplies container that they float themselves and easily located ,found in extreme conditions. ( Still have techincal issues ).

    I envy you have the plan to do what you want.

    Will you consider very warm and breathable clothing ? I am designing a core-tex suit like swim suit but breathable and water proof , double layer ( but the breathability of the material I got is not as comfortable as core-tex that I could not obtain.)

    Make sure you have enough and appropriate clothing.
     
  4. enjoysurvival
    Joined: Nov 2007
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    enjoysurvival Junior Member

    an island

    Hi,

    Just curious,

    Will you have to tendency to land on an unknown island during the trip?
     
  5. wmonastra
    Joined: Jun 2006
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    Location: ChristChurch New Zealand

    wmonastra Junior Member

    HI There

    im keen to learn more about your survival gear, what are you thinking of doing in the way of dry suits?? im also keen to look at trying gear that you make on my trail runs before i actully head off.i will only have the bare basics of electrics,running lights, i will be using a hurricane lamp inside for lighting and assistance in heating. I will use my mountaineering handheld gps, (its both water proof and shock proof and runs on 3 penlight batts for up to 3 weeks per set of batts.)I will also have my laptop and mp3 player for diary, music and photos etc, i will take all my ice climbing gear and other winter toys, (ive been climbing for years and have alot of winterised gear which im trying to adapt to the trip, as its both water and shock proof) the idea is to go and find small islands and camp out and explore them do some sking and climbing etc, sail around and have a look and learn more about the area.

    In NZ we have a steel yacht made by a designer called Ganley. They come in all sizes and ive been told that they are strong and great offshore. Can anybody back that up or maybe owns one that can tell me more about them please. I will be living on it full time so that side of it will also have to be taken into account.

    Looking forward to the responses.:)
     
  6. DanishBagger
    Joined: Feb 2006
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    DanishBagger Never Again

    If drysuits, layer up. It's like wearing a plastic bag. I prefer to use icebreaker underneath my drysuit when I sail here in winter, because it's merino wool (isolates when wet, and you don't smell as bad as fast as you will with man made fibres), but the brand is unimportant, of course.

    Yesterday I decided to buy me a float coat – but if I were going to Svalbard or further north I would be giving myself a float suit, and if at all possible a survival suit (but those things are even more expensive).

    Your plan sounds really nice. I hope you will keep a trip log and take some nice pictures while underway? I'd love to read about it, when you get that far.

    Steel is supposed to be great, but at your size (that would include "my" size when I get around to go really, really north), the material really doesn't seem that important, construction much more so.
     
  7. wmonastra
    Joined: Jun 2006
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    wmonastra Junior Member

    I was just reading another sailing forum and read that kevler cover glass or ply is stronger than steel and alot lighter??and would be far better for the ice.

    Can anybody confirm or deny this form of building??? I mean if its true then i may as well just cover my glass 30ft yacht now and move my trip forward as my boat is more than suitable for heading offshore. i only wanted steel in the ice as i thought it be alot safer. it looks like i may be wrong???
    your thoughts.
     
  8. DanishBagger
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    DanishBagger Never Again

    I'm not a naval architect, you have to know that, but I am quite sure one cannot make the blanket statement that kevlar over ply is stronger than steel. The fact of the matter is, that I can build a boat with kevlar over ply that will sink the moment it hits something (because the hull itself isn't strong enough behuind that ply, or the ply isn't strong enough, or something else to that end), and other the other hand, one can build a wooden boat that will be much stronger than a random steel boat. I would never choose a boat on material alone, although I do have some preferences. But to me, the material itself is only part of the equation. Not the end-all choice.

    I like stripplanked boats and (unpainted) aluminium – those are my preferences, if I really have to choose.

    Also, I would be wary of covering a boat of glassfibre with kevlar, simply because of the extreme cold you will see, because that means you will have the stove roaring. I'd be worried about the difference between the heat and the cold making glass fibre burst the much stiffer kevlar. Kevlar is stiff, ad really not forgiving, and the "thermostat"-effect (my own word, hope it makes sense) might result in long term damage (two different materials where one expands more than the other because of heat).
     

  9. DanishBagger
    Joined: Feb 2006
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    DanishBagger Never Again

    Btw, at one time I considered covering my strip plank one with mylar, thinking that mylar is much more flexing than kevlar, and although it wouldn't make the hull stiffer, I figured it would be better at controlling the hole, should it happen. As it turned out, I never did, because mylar is ***** to work with. Well, it was too me – I wasn't able to handle it as I should.
     
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