Large Sailing Scow

Discussion in 'Boat Design' started by bblair, Sep 29, 2004.

  1. bblair
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    bblair Junior Member

    A few years ago I saw a wooden sailing scow which had been owner-built in Port Townsend, Wa. I'm interested in having a fiberglas version of this built (I have no desire to try to maintain a large wood boat). I would like to hear some discussion of the desirable and undesirable characteristics of such a hull- I have some experience in power scows in the Gulf of Alaska and Prince William Sound, so I'm not completely new to the type. I would also like some direction as to where to find plans for such a hull. All of the referenced plans I have been able to find were for dinghy-sized craft.
    My aim is to have a vessel of fairly simple design which can sail fast in the proper conditions, have a lot of space, and not be as restricted with regard to it's weight-carrrying capacity as would a comparable catamaran. The size I have in mind is 12 to 16 meters.
    Thanks, everybody, in advance!
     
  2. garydierking
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    garydierking Senior Member

    Find a copy of "American Small Sailing Craft" by Howard Chapelle. There's a section on "Gulf Scow Schooners" of about the size you're looking for. They were traditionally used from New Orleans along the coast to Mexico and actually look quite fast.
     
  3. jawillia
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    jawillia New Member

    large scow

    The San Francisco Bay Martime Museum has plans for the ALMA, a scow schooner that is still sailing (1891). The plans cost $42.00 and contain some 6 sheets. Just got mine. Very detailed and can be scaled (which is what I am doing). Don't have the URL handy but a web search with "ALMA scow schooner" will get you there.
     
  4. bblair
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    bblair Junior Member

    Thanks for your tip. I know about the Alma, but had no idea that detailed plans were available. $42 seems an incredible bargain. I would estimate that I've invested 100+ hrs in just searching for plans. Thanks again!
     
  5. sharpii2
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    sharpii2 Senior Member

    Large (cruising size) sailing scows I know of

    Hi bblair.

    Here are some cruising size Scows I know of. AIR stands for As I Recall.

    Phil Bolger

    Super Brick Straight sided, deep rocker*.
    Length 19.5ft
    Beam 8ft
    Displ. 3800lbs
    Cat rigged w/boomed lateen

    Scow Schooner Curved, slightly flaired sides, deep rocker.
    Length 28ft
    Beam 9ft 10in
    Gaff Schooner w/two masts + a jib

    George Buehler

    Rufus Straight sides, deep raking bow, transom, shallow rocker.
    Length 30ft (AIR)
    Beam 10ft
    Cat rigged w/ a large gaff

    *By deep rocker, I mean a continuous curve, fore and aft, that sweeps well clear of the waterline at at least one end.

    These are the three that I know of.

    Bill Garden designed a scow schooner as well, but I do not remember any of the particulers of it. (AIR) it had a dead flat bottom, rockered ends, a deep raked bow transom, and a vertical stern transom.

    I have been very fascinated with this type over the years. My 1st boat was a scow in the form of a sailboard. It was 10ft long 4ft wide and it weighed at least 180lbs dry (which it usually wasn't). It had 85sft of sail. and it planed routinely. It was poorly built (by yours truly) and it only sailed about twelve times before it rotted out.
    I am presently designing a new boat that will combine the vertues of my old scow and my much beloved Super Snark. It will be a deep rockered, straight sided, and very narrow for its length. (12ft long + 3ft wide) The idea being that by the time it heels over enough to put the vertical transoms at the waterline, it will present enough 'V' to the water to keep it from pounding as much.
    Not only that, but it will have a DL that is significantly lower under sail than sitting upright. If the design is successful, I am toying with the idea of building a live aboard version that would be 28ft x 7ft and would live either on the Intercoastal Waterway or the Misissippi.

    Scow advantages:

    Lower construction cost. (Both in hull construction and interior installation),
    Enormous sail carrying ability (for a monohull),
    Shallow draft and can be beeched on a soft bottom (mud or sand), and
    Good to excellent payload.

    Scow disadvantages:

    Heavy for its length and beam,
    Can pound ferociously in rough water (and needs to be built stronger to account for this),
    Has a very limited range of stability (especially the shallow rockered and flat bottomed versions) and can capsize with little or no warning if over pressed, and
    Is seen by many as ugly and 'un boat like' (maybe thats why I like them so much).

    I really wonder about your plan to build it out of GRP. The scow hull type likes matterials that are stiff for thier weight such as lumber and plywood. With a GRP hull you may end up using an inordinate amount of of roving, matt, and polyester. This could make a very heavy hull or a hull that needs lots of deep 'hat sectioned' frame members.
    Might I suggest you go with epoxy saturated plywood. It will probably have similer maintainence requirements to GRP but be much stiffer for its weight (undeniably heavy by its own right) and cost.

    Its interesting to note that according to may nautical historians (especially Chapelle) sailing scows were quite numerous. Some have said that they were the most comon boat type seen. Now there is little memory of them. I hardly see any examples of them at all in most marine mueseums.
    Currious.

    Best of luck

    Bob
     
  6. bblair
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    bblair Junior Member

    Pros and Cons of Scows

    I myself used to run a power scow in Alaska. I used it for tendering fish from salmon boats, for delivering freight of various kinds to operations in the Prince William Sound, and as a tow boat for towing logs. There are actually quite a few power scows in those waters (ex WWII craft??), used usually for either tendering or for crabbing. Most of them either were built with or have had a pointed bow added, but the one I ran was square-bowed. It was REAL heavy (planked w/ 4" lumber), and really stout. Also really slow. In the more exposed waters of the North Pacific a lot of guys use stabilizers to minimize the pounding and the wallowing, but I have a different idea of how I would like to handle that.
    I'm in contact with a boat yard in Poland which does really excellent work (the build boats as subcontractors for Swan, for instance) who is willing to work with me as far as construction and materials. Once I have a set of plans to work with, I'll discuss materials with him. What I have in mind is about 45'L X ~15' beam, and I have some interesting (foolish, maybe?) ideas as far as rigging. One of the reasons I'm thinking of a scow is that I'm a motorcycle enthusiast, and when I go cruising I want to be able to bring my Harley along. You can probably imagine ho foolish people find that idea...
    You can email me directly at carhaulerbrian@yahoo.com. There are some things I don't wish to broadcast on an open forum until I have a chance to try them out for myself (trying to minimize the egg on my face). I'll look forward to hearing from you.
    Brian
     
  7. gonzo
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    gonzo Senior Member

    Boat plans don't scale well beyond 15% or so. Unless you are experienced in design it would be bettter to get one on the size you want. What do you mean by fast? They are sailing barges.
     
  8. Sean Herron
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    Sean Herron Senior Member

    Attached Files:

  9. sharpii2
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    sharpii2 Senior Member

    Harey clydesdales?

    Hi gonzo.

    When loaded, you are absolutely right. Most scows were work boats and were expected to have large payloads.

    When empty, that was a whole other matter.

    When most monohulls are sailing with no load, the WL beam shrinks and the WL stays pretty much the same. When most scows are sailing with no load, the WL shrinks and the WL Beam stays almost the same. Even this does not make for speedy sailing. But what happens when the scow heels? The WL starts to lengthen and the WL Beam either stays the same or shrinks. Now you have everthing needed for high speed sailing: Long (relatively speaking) WL, moderate to small Beam, and the righting moment to carry a relative huge spread of sail.

    And to that you can add the fact that, like most monohulls, the sailing waterplane is asymetrical. The only difference is is that with a scow the gentler curve is to leeward, but with most monos, the opposite is true. What this means is that a scow is going to have far less weather helm when hard pressed than your typical mono.

    In protected water, your typical light scow will walk away from any conventional mono of the same length and level of technology.
    The crude ten footer (deep rocker, straight sides) I built as a teenager out of plywood and with taped plastic drop cloths for sails, planed routinely. I have no idea how fast it went for there were no other sailboats in the area, but I always felt it lift every time it caught the wind.

    Until the introduction of multihulls, the fastest sailboats were light scows.
    Speeds of over 23kts were recorded for one large racing scow.

    Bob
     
  10. gonzo
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    gonzo Senior Member

    Yes, the scows you are referring to (sandbaggers) are still very fast. However, they have a large crew to move the ballast around. Scows do well downwind.
     
  11. CT 249
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    CT 249 Senior Member


    With respect, Bob; scows can be very cool, but can they really "walk away" from conventional monos? The C scow is rated only a fraction faster than the 505, which is about 4' shorter, the M20 is significantly slower. The MC isn't much faster than the Laser. Sure, the A Scow is fast, but it's also 38' long!

    The Fireball scow is about the same measurements and ratios as conventional boats like the 470, and surprise surprise it's just about exactly the same in all-round performance. Other scow types (Australian Rainbow, Butterfly, Tempo were pretty much similar in all-round pace to boats of similar dimensions but conventional shape.

    The Australian scow-type Moths were quick little beasts, just 11' long but as fast as a Contender and significantly faster than a Finn or Laser. But they also had 1.2mm ply decks, bottoms of about 3mm, big 80 ft2 high-aspect fully battened rigs and hulls around 45lb or less. In the heyday of the Moth, when it was the world's biggest development class, the battle between the conventional boats and the scows always got down to the strrength of the wind; the scows did not "walk away" until the breeze got over 12 knots or so, instead they got beaten by boats that looked like narrow versions of the Europe. Once the conventional stemhead skiff hulls developed their shape they were almost always faster, and a modern narrow skiff is much faster still.

    I'm not knocking scows, I still have a scow Moth and it's a great little boat; but they were not faster than conventional shapes all-round apart from out here (Australia) where the wind is fairly strong and the scow's stability makes it a good performer.
     
  12. sharpii2
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    sharpii2 Senior Member

    I guess I should have stipulated 'without hiking'. With hiking the narrower the hull the better because it needs righting arm far less than it needs low wave making. Also, it very hard to find a lot of wind without at least some chop. the sharp bowed craft slices through while th scow tries to go over it.

    But your point is well taken.

    Bob
     
  13. SamSam
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    SamSam Senior Member

    Here is a method that I think would work to build what you want in fiberglass. It is how Carolina Skiffs are built, this is their patent which just expired a few weeks ago, it is now public domain. It would have to be engineered to the size you want, but I do believe it would work. Go to the site I'll list and put in this number,4495884, in the search box. Sam

    http://patft.uspto.gov/netahtml/srchnum.htm
     
  14. catamaran29
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    catamaran29 Junior Member

    About scow plans

    There is a catalog available from the Sithsonian. the section on American Small Craft, and others have plans availabe. I got Chapelles 36' scow plans for about $18.00. Some sets are more complete than others. There are drawings of San Franscisco bay schooner scows, commercial vessels of the 19th and early 20th century, "Granite" sloops of New England, Chapelles own designs (scantlings included), and more.
     

  15. safewalrus
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    safewalrus Ancient Marriner

    Scows - anybody been to china? call em junks/sanpans I believe? Same same scow just more rice (and that's the worst cargo you can carry nest to humans which is notrhing to do with what we's talking about here)

    the Walrus
     
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