Perhaps Beebe got it wrong

Discussion in 'Boat Design' started by Mik the stick, Dec 11, 2013.

  1. Mik the stick
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    Mik the stick Senior Member

    I haven't posted anything for a while I've been trying to learn a bit rather than just ask.
    To recap The task i set myself was to design (as far as possible) a boat in which an experienced Mariner could cross the Atlantic In SAFETY. Starting with something like a Nordhaven 46. Where I think Beebe may have got it wrong was he intended to motor across the atlantic sailing if and when he had to. If as I did you take a starting point of 40-50ft boat. They require a lot of fuel which needs a bigger boat to carry it and perhaps a bigger engine. You can motor away from bad weather even though you can't out run it.

    Sails on most motor sailors and Beebe's boat in particular will not give a great turn of speed. So I looked at Sail cruisers with auxilliery engines. They don't seem to have nearly enough fuel. So change of strategy SAIL across the Atlantic and MOTOR when caught in serious weather or the wind fails or blows the wrong way.

    Ted Brewers designs with 120/150Gal of fuel probably still don' carry enough fuel.
    I am at the moment working on a design of 42ft LOA >12ft Beam ~6ft draft. I have a copy of Ted's book Understanding Yacht Design and Gerrs book Elements of boat strength which helps me estimate displacement (and much more). I will post the results of my calculations eventually Because I am looking at sailing type yachts I thought I would try to incorporate things to make it fall into a particular race class but I can't follow the rules. If someone knows what class the above dimensions fall into please share it with me. This my fantasy boat will be called BLACK MAGIC afterall it's what Naval architects do.
    Mik the stick
     
  2. bregalad
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    bregalad Senior Member

    Ignore all rating rules. The rules are generally designed to predict the performance characteristics of different shapes of boats and handicap them in an effort to level the playing field for racing.

    Eventually designers find ways to exploit the rules and often the boat then sport odd refinements that serve no useful purpose, other than to deceive the rule. If they become too successful the rules are modified, or discarded in favor of a new set of rules.

    Unless you intend to campaign the boat under one rule or another just ignore them. Superb cruising boats, and even some successful racing boats have been designed with little to no regard for any rule.
     
  3. Mik the stick
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    Mik the stick Senior Member

    Thank you
    So Far I have chosen a Beta diesel ~35hp. 400 imp Gal of fuel wouldn't get it across the Atlantic even if I could squeeze it in. What I'm working on is a pilot house in addition to an external steering station. Yacht racers don't seem to mind the wet when they are racing.
     
  4. viking north
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    viking north VINLAND

    Possibly you're looking at it all wrong. Instead of increasing the size of the boat just to carry ample fuel to allow motoring a long distance. Why not shorten the distance --Island Hop. Two options, reverse Viking Route, Newfoundland to Greenland to Iceland to Europe. I stand corrected but i seem to recall the longest leg is 800miles. Or Newfoundland to Ireland, 1500 miles and if you get out into the gulf stream you have a 3 knot stream in your favor. In either case you should be able to sail 60 to 75 % of the distances.
     
  5. Petros
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    Petros Senior Member

    many many poeple routinely cross the atlantic in 26 to 35 ft sailboats, much less gear, much less fuel required, much less maintenace, much easier to single hand,e tc. I do not know why so many people think you need a 45-50 boat to go long distance. with modern weather information you just need to plan ahead to avoid the big dangerous storms.

    The Pardees sailed a well designed 24 ft wood sailboat without a motor all over the world. A bit cramped I think for two people (their next boat was 27 ft), but they just planned their route carefully and kept up to date on the weather. without a motor you do not need to carry fuel, and you are much less likely to be the target of thieves too.
     
  6. michael pierzga
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    michael pierzga Senior Member


    At sea you need sails to dampen roll motion.

    These sails add tremedous range to a motorsailor. I can be slowly chugging under motor at reduced rpms and 6 knots to save fuel..a bit of wind comes up and presto..Im motorsailing at 8 knots.
    Thats a free 50 miles over 24 hours
    Ive crossed the atlantic many times on motorsailors with a technical fuel range of 600 miles.

    Only design a true motorsailor if you endeavor to sail long range economically
     
  7. Baltic Bandit

    Baltic Bandit Previous Member

    While it is true you can cross the atlantic safely iin a 25'-30' boat,

    A) the shorter the boat, the longer it takes
    b) unless you have experience passage making - don't build a boat for this purpose.

    Passage making fundamentally is quite boring. So I would recommend doing something like buying a cheap (and you can get a bluewater worthy boat for around $20k-$30k) 25' bluewater boat, and then doing a 7 day singlehanded offshore cruise along one of the coasts

    If you still think passage making is for you, then and only then start designing a boat.

    Now to me the ideal boat is about 40' The loads on the sails are manageable, there's enough space below that two people can find space away from each other even if they are cooped up down below riding out a storm - and she's typically fast enough (9 knots) that you will average 150nm/day and have days where you get over 200nm.

    that means you are at sea for 20 days (3 weeks). Not to horrible but a serious chunk of time to be alone with no one to talk to - hence the suggestion you try it fiirst
     
  8. FAST FRED
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    FAST FRED Senior Member

    Even at the trawler crawl speed is the big factor in fuel burn,simply slowing down a bit can extend the range a whole lot .

    Light helps , skinny helps and a bit of rag is an easy way to smooth the ride.

    With a prop requirement of at least 2 HP per ton (2240lbs) and a bit of reserve required for the full fuel beginning of the voyage , an engine of 4 HP per ton would work fine .

    Remember the accessory load , AC power ,DC charging , perhaps air cond and Hyd for the windlass , bow thruster and dink hoist.

    There are any number of larger sail hulls that might be easy to reduce the draft , and use the sail gear with a cut down mast, preferably deck mounted in a tabernakle for inshore cruising.

    At 6K 2400 miles is 400 hours , perhaps 1000G -1200G of fuel .

    Not a fantastic load for a 40 ft water line , perhaps 6 -8 inches more draft at the start.

    Remember 99.99% of power boats were not built with ocean crossing scantlings , until they get very large , and very costly

    Not the problem with an old sail hull.
     
  9. Baltic Bandit

    Baltic Bandit Previous Member

    You can get all sorts of ready to go older sailboat hulls a Gulfstar 45 would be a solid starting point. Though why you would want to ditch the rig and go to primary put put power seems odd to me. The thing is that the limit on speed for these boats is the waterline length and form drag. And you will do a lot better if you get into the trade winds, toss up your main and a cruising spinnaker, Turn on Nikki (NKE Electronics), and then go about doing what you want to do.

    Total cost will probably set you back $100k US - far less than you can build something from scratch for.

    Frankly the only reason to build something yourself is because you want to. But its going to be more expensive than buying
     
  10. Milehog
    Joined: Aug 2006
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    Milehog Clever Quip

    Sail boats without masts are snappy, uncomfortable things. Reducing ballast helps but then it will likely cork about.
     
  11. FAST FRED
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    FAST FRED Senior Member

    >Reducing ballast helps but then it will likely cork about.<

    Not with fuel tanks filled.

    Perhaps the boat would be best off with dual bladder tanks in a reinforced hold area.

    Fuel when extreme range is desired ,or fresh water for coastal cruising , and both almost empty for light ship when inland on rivers?
     
  12. michael pierzga
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    michael pierzga Senior Member

    Why would you remove the mast from a motorsailer ?

    When sheeted tight I can motorsail at 25 degree wind angle.

    As for tanks..you might be able to squeeze in an extra few hundred liters.

    I find it easier to use plastic barrels of fuel on deck...then as soon as enough fuel has been burned in the internal tanls , stick a hose in the barrel and siphon into the internal tank.

    Once the passage is over dispose of the plastic barrels.

    Get the barrels cheap from agricultural supply industry

    [​IMG]
     
  13. FAST FRED
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    FAST FRED Senior Member

    >Get the barrels cheap from agricultural supply industry<


    OK for short term diesel storage but in the USA the agriculture bbls will leak in a year or so.
    \
    Dont ask how I know!

    >Why would you remove the mast from a motorsailer ?<

    The motor sailor is seldom expected to sail in light winds (under 8K as most sailboats can easily do) so there is very little reason for a tall mast and an acre of sails.

    A short rig with a fully battened main can even be run into the wind with no damage to the sail.

    Motoring Inshore rivers and canals require this at times.

    A roller furled jib is easy to set , and if the double luff style can be very effective down wind .

    If keel ballast is removed to increase the fuel payload , the shorter mast will not cause problems , and may still have enough mass to quiet the boats motion.

    A big old pure sailor , recycled to a 50/50 M/S would be an easy and comfortable offshore cruiser.And modest in cost.

    Far safer than an old motor boat with a mast stuck on top.
     
  14. Baltic Bandit

    Baltic Bandit Previous Member

    Well most motorsailors are undercanvassed to start out with, though 8knots of breeze is not all that light if you can press on some canvas and aren't driving to weather. In the ocean you tend to have ...Under 6 knots (in which case you motor) or 10+, in which case you put up sail (unless going upwind).

    when I lived aboard a 50' ketch, in 8-10 on a broad reach with a Mizzen Stays'l, Mizzen, Main and big genny we would be doing 8.5 knots. I remember one beautiful summer close reaching (60deg to the wind) with Jib, Main and Mizzen, doing 3 knots VMG with 6 knots of boatspeed with the Brandenburg Concertos pouring out the on deck speakers, my wife sitting on one side of the center cockpit reading, me on the other side, a bottle of Pinot Grigio in the gimbal on the steering pedestal and me steering with my toes.

    The genset was whispering quietly (the advantage of lots of diesel tankage) but the loud roar of the main engine did not exist

    With a ketch rig the ability to balance the boat so that no AP was needed until the waves hit 1 meter was brilliant.

    sure, when the tide turned hard against us, we did fire up the big Iron Genny, but if you are passage making, even that's not so critical.

    Remember that with passage making, you could always get their faster and cheaper with a plane ticket.
     

  15. viking north
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    viking north VINLAND

    45gal. plastic drums on deck best be fitted and steel strapped into a cradle which is in turn thru bolted to the deck in a similar set up as some life raft's are. Burn this fuel prior to that in your main tanks to reduce danger of breaking loose and reducing top hamper. Just the thought of 45gal. of fuel in a drum on deck in a storm gives me the willies. Much better to store it in smaller drums or 5/10 gal fuel cans. 20gal. imp.drums are readily available here in Canada. Car wash companies buy their detergent in 20gal drums. Again they have to be properly secured in a drum cradle which in turn should be thru bolted to the deck for offshore work.
     
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