Yard Class ( proposed sailboat class)

Discussion in 'Sailboats' started by sharpii2, Jan 9, 2015.

  1. sharpii2
    Joined: May 2004
    Posts: 1,878
    Likes: 87, Points: 48, Legacy Rep: 611
    Location: Michigan, USA

    sharpii2 Senior Member

    Here’s an idea I’ve been playing with, while thinking about a sailboat racing class that would be both inexpensive and easy to be competitive in, for crews in their advanced years.

    I think the prime measurement to set an absolute limit on is the Beam. This, more than anything else, limit’s the Rig Height and Sail Area. A small Beam, with hiking effectively eliminated, limits how far one must scoot between tacks. A small Beam also limits rig loads.

    Tying Rig Height to Hull Length, allows choices to be made on ultimate speed vs. likely pointing ability. A longer Hull means a shorter rig, but not necessarily a smaller one.

    Appendage depth is limited to prevent flimsy, deep boards.

    Well. What do you think?

    What would a fast design, under this rule, look like?

    Here's the rules:

    YARD CLASS

    (A Sum-Rule racing class)


    A.) BEAM to be limited to 3.0 ft ( 91.5 cm).

    B.) BEAM to be measured between furthest points of outer hull skins.

    C.) Whales, Guards, and Side Center Board or Side Dagger Board staples can extend up to 3.0 inches (7.6 cm) past this maximum Beam, on either or both sides.

    D.) Crew must sit at least 6.0 inches (15.2 cm) below the lowest point of the shear.

    E.) Rig Height, measured from highest point of the sail to the lowest point of the sail, plus the Hull Length, must not exceed 26 ft, 2.5 inches (8.0 m).

    F.) Hull Length is measured between two vertical lines, and includes any platforms, but does not include rudders or spars.

    G.) No External Ballast (Ballast outside the Hull Envelope), other than the minimum needed to keep appendages submerged, is allowed.

    H.) Internal Ballast (Ballast inside the Hull Envelope) can be water, stone, sand, or gravel only. No metal ballast is allowed.

    I.) Appendage depth, measured from the Load Waterline, is not to exceed 3.0 ft inches (91.5 cm)

    J.) Emergency Flotation, adequate to keep the boat level and the lowest point of the shear and/or ‘Board Slot(s)’ 3.0 inches (7.6 cm) above the water, when the boat is swamped, must be provided.

    K.) Sails to be made out of ’poly-tarps’ only.

    L.) Specialized down wind sails are not allowed.

    M.) Spars to be made of aluminum, steel, or wood only.
     
  2. Skyak
    Joined: Jul 2012
    Posts: 1,194
    Likes: 25, Points: 38, Legacy Rep: 152
    Location: United States

    Skyak Senior Member

    My first thought is that the old or infirm are not eager to get involved in a development class and are likely to go with a one design fleet that matches their ability.

    My second thought is that a good development class keeps performance reasonably contained and high to make competition interesting and does something to contain cost so the podium can not simply be bought. I don't see that this proposed rule succeeds on either count. Cut the keel and bottom of the hull out of the densest stone you can. clad in wood veneer and optimize the mast height/hull length for the righting.

    My last thought is that someone interested in such a boat would go for a mini AC or 2.4 class.
     
  3. gonzo
    Joined: Aug 2002
    Posts: 13,613
    Likes: 382, Points: 93, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    A 3 foot beam with a 26 foot mast is a boat that needs to hike hard to keep from capsizing. Old people would be safer on an under-rigged cat.
     
  4. Waterwitch
    Joined: Oct 2012
    Posts: 93
    Likes: 9, Points: 8, Legacy Rep: 20
    Location: North East USA

    Waterwitch Junior Member

    I thought the beam to mast height ratio to be rather demented too with the draft limitation. The only thing inexpensive about the class is the poly tarp. Then again how much am I paying these days for a big tarp for a boat cover?
    I don't do shrink wrap...
     
  5. messabout
    Joined: Jan 2006
    Posts: 2,985
    Likes: 191, Points: 63, Legacy Rep: 1279
    Location: Lakeland Fl USA

    messabout Senior Member

    Your boat reminds me of the International 10 square meter Canoe. as far as it goes.

    A rule, like rule D, is unrealistic for a 36 inch beam especially with a tall mast. A more realistic mast for such a skinny boat would limit total length to 16 feet.

    If this is to be a "yard Boat".... I assume prematurely that the term is to imply cheap and dirty, then hull material needs to be limited to wood, ply or other wood. A 18 footer with 3 foot beam could be a real fun boat if not overpowered. It could be a pretty quick boat too. I think a maximum sail area could be required without making measurement too complicated or burdensome. Let the sail fit inside a rectangular plane figure of some dimension or other. Thus Measurements are simple. It fits in the box or is does not.

    A "yard boat" could have hard chines and plumb sides and still be a helluva boat, cheap, simple, and capable of planeing. For an OP with a screen name like Sharpi, I reckon it ought to be a flat bottomed boat too. Flat bottom, hard chine, plumb sides, but still capable of some pleasing performance. That puts the boat into the realm of the builder with limited builder experience. Beginning to sound like a shrunken 110 without ballast.
     
  6. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 471, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    A good "yard boat" might be a PD just with a pointy end. I'd like to see some flare in the topsides, but this could be the same from bow to stern to keep things simple. Flat bottom, tapes seams, lots of initial stability and a bit more area than it really needs. Then again, maybe a scow like shape.
     
  7. gggGuest
    Joined: Feb 2005
    Posts: 808
    Likes: 17, Points: 18, Legacy Rep: 76
    Location: UK

    gggGuest ...

    Why would you want to mandate vertical sides?

    For simplicity of building there are two boats that have struck me in recent years.

    One is the late great John Spencer's Firebug:

    http://www.firebug.co.nz/design.html

    Having the same angle at all the chines right through the boat struck me as genius, so did the symmetry in having the same section at each end of the cockpit centre.

    The other is Len Morris Mk 2 Moth from the 50s, which at first sight the very simplest of scows with flat bottom and vertical sides, but somehow has very subtle shaping.

    http://www.earwigoagin.blogspot.co.uk/2014/04/scow-moth-plans-australian-len-morris.html

    The worry is I think you have to be a real design genius to make a decent shaped boat with such limiting restrictions on chine angles and so on.
     
  8. latestarter
    Joined: Jul 2010
    Posts: 339
    Likes: 28, Points: 28, Legacy Rep: 233
    Location: N.W. England

    latestarter Senior Member

    E.) Rig Height, measured from highest point of the sail to the lowest point of the sail, plus the Hull Length, must not exceed 26 ft, 2.5 inches (8.0 m).

    It is not a 26 ft mast, for a triangular sail, it is luff length + hull length less than 26 ft.
     
  9. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 471, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    The Moths used vertical sides, simply because it's a faster boat this way. The sharpie was given this treatment too in it's heyday, for the same reason. The Firebug seems like a lot more effort (multi chine) for a little boat, with limited ability.

    Yes, it will be a tough design job to make a simple, good performance boat with and easy, cheap build. I'm inclined to go performance dinghy, with a fat section, to keep the old timers in the boat, but still get up and scoot. Basically a triangular bottom panel, common topside flare to keep it easy, enough rocker to hold up fat old guys and toss a windsurfer rig on it.

    The attached has a flat bottom, common flare sides, enough rocker to make it work in it's 10' length (48" beam), a little style with the reversed transom and she'll get up and scoot with a fair bit of area. A very simple thing to tape up, add a little foredeck to hold up the stick and away you go. This is showing a 6" LWL and about 500 pounds of displacement, so a fat skipper, a cooler full of beer and the boat too.
     

    Attached Files:

  10. ALL AT SEA
    Joined: Nov 2013
    Posts: 24
    Likes: 1, Points: 3, Legacy Rep: 10
    Location: Australia

    ALL AT SEA Junior Member

  11. Richard Woods
    Joined: Jun 2006
    Posts: 2,179
    Likes: 145, Points: 63, Legacy Rep: 1244
    Location: UK, USA and Canada

    Richard Woods Woods Designs

    Not sure what is meant by "advanced years".

    Having said that, my father is 90 and still dinghy sails in the English Channel. He has a WalkerBay 10 with inflatable collars. The hardest things for him are launching, and particularly retrieving, the boat singlehanded on a shingle beach. The design priorities were light weight and the fact that he can never capsize so needed a very stable boat. He also finds it difficult to turn round in the boat (but then he had that problem 50 years ago when he used to crew for me!)

    So a boat like the Walker Bay works, my Tryst trimaran would also suit him very well

    http://sailingcatamarans.com/index.php/designs/27-trimarans-under-25/428-tryst-trimaran

    I am in my 60's, so too young to consider myself "advancing years" but I do find it a very easy, safe boat to sail

    Then there are people like Peter Conway, who races a foiling Moth at 80, see this older post

    http://www.yachtsandyachting.com/news/160160/What-age-is-best-to-start-foiling

    so first decide on the market and what people need, then think about the boat and how it solves those requirements. Don't do it the other way round. As Adhoc will say "Get the SOR finalised first"

    Richard Woods of Woods Designs

    www.sailingcatamarans.com
     
  12. sharpii2
    Joined: May 2004
    Posts: 1,878
    Likes: 87, Points: 48, Legacy Rep: 611
    Location: Michigan, USA

    sharpii2 Senior Member

    A 26 ft mast would mean a 0.00 ft long hull.

    Yeah, that would be a challenge ;)

    Read paragraph E.)
     
  13. sharpii2
    Joined: May 2004
    Posts: 1,878
    Likes: 87, Points: 48, Legacy Rep: 611
    Location: Michigan, USA

    sharpii2 Senior Member

    An interesting point, and one I have considered. This class would be meant to supplement them, not to replace them. The boats I have in mind will be easier to launch and could be launched fro a beach, on a small lake.
     
  14. Richard Woods
    Joined: Jun 2006
    Posts: 2,179
    Likes: 145, Points: 63, Legacy Rep: 1244
    Location: UK, USA and Canada

    Richard Woods Woods Designs


  15. sharpii2
    Joined: May 2004
    Posts: 1,878
    Likes: 87, Points: 48, Legacy Rep: 611
    Location: Michigan, USA

    sharpii2 Senior Member

    Just like I was thinking thinking. Since the boat is likely to be narrow for its length, due to the 3.0 ft Beam limit, it would be easy to put a pointed bow on it, without sacrificing too much initial stability.

    Getting a lot of SA with a low CA is not a usual challenge in racing dinghy design. I thought it would be interesting to make it one. That's why the SA is not limited.
     
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.