Schooner sail plan - need help

Discussion in 'Sailboats' started by Glider, Aug 31, 2008.

  1. Glider
    Joined: Nov 2006
    Posts: 8
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Russia

    Glider Junior Member

    I'm building a gaff-rigged schooner and need to make some decisions regarding sail plan/rigging. I have some very preliminary sketches and would like to ask you for advice.

    Few general notes on the boat:
    • The hull of the boat is a slightly modified George Buehler's Juno, 37' (hull lines made similar to Juna).
    • Displacement 10 tons, external ballast weight 2 tons.
    • Two cabins, center cockpit (just aft of the main mast).
    • Current construction stage - finishing planking.
    • Deck and mast partners are already in place, but no holes made in them (so position of the masts is more or less fixed).
    • The boat will be sailed shorthanded, so I would like to avoid backstays.
    My current vision of the working sail plan is the following:
    sailplan.PNG

    • Lead = 10% (CLP and LWL calculated including rudder)
    • Working sails area = 67 sq.m = 720 sq.ft

    Underwater profile (sorry for the bad picture - I'm not CAD expert):
    profile.PNG

    I basically have two main questions:
    1. The working sail plan on the sketch above - does it seem reasonable? Shall I change something?
    2. The light air sail plan - how would you do it? I would like to avoid building a topmast, but I would like to be able to use topsail and/or fisherman's staysail. For the masts, I have sticks 42' long, but my ballast is relatively lightweight so I'm not sure if I shall make main mast any longer (on the sketch, it's 36').

    Will appreciate your comments!

    Regards,
    Andrey
     
  2. MikeJohns
    Joined: Aug 2004
    Posts: 3,192
    Likes: 208, Points: 63, Legacy Rep: 2054
    Location: Australia

    MikeJohns Senior Member

    My understanding is that the topmast is required to increase the luff length of the effective area for windward work particulalry in lighter air.

    SAD is a ratio you can look up but it depends significantly on the geographic area you intend to operate in. Most higher lattitude boats benefit from the ease of handling from ruduced rigs. Even in the trades when they are blowing you seldom shake out the reefs even on a low SAD cruising vessel, but then you will need top masts for light air since the shorter masted Gaffer doesn't support big light air headsails very well.

    Unfortunately only experience will tell you which compromises suit your style of sailing.
     
  3. lazeyjack

    lazeyjack Guest

    privet!! Glider
    would you consider the modern schooner rig , which is very successful?are you in Sochi< Black Sea, Murmansk,or St P, or Vladivostok?
    got your mail Mike,
     
  4. Gilbert
    Joined: Aug 2004
    Posts: 525
    Likes: 5, Points: 28, Legacy Rep: 28
    Location: Cathlamet, WA

    Gilbert Senior Member

    You could rake the masts a little more if you want to do away with running backstays. The stay sail should be bigger: the angle at the peak of the sail should not be less than 29 degrees, make it as large as you can within reason. Otherwise, I think it looks really good.
     
  5. Tad
    Joined: Mar 2002
    Posts: 2,321
    Likes: 214, Points: 73, Legacy Rep: 2281
    Location: Flattop Islands

    Tad Boat Designer

    A gaff schooner rig is probably not the best choice for this hull. Due to low ballast ratio, high vcg, and low form stability due to narrow waterline and double ends, the heavy schooner rig will mean sailing on your ear a great deal (or early reefing).

    If you really must have the schooner build all spars as light as possible (hollow) and go light on the rigging. Reasonable headstay tension will require runners. The gaffs preclude standing backstays, thus you really need runners for maximum rig security.

    In light air I would set a big Genoa from the mainmast head, like a mizzen staysail.
     
  6. TeddyDiver
    Joined: Dec 2007
    Posts: 2,615
    Likes: 136, Points: 73, Legacy Rep: 1650
    Location: Finland/Norway

    TeddyDiver Gollywobbler

    Topsails without topmast..with Cornish yard or topsail yard with jack yard. Or maybe something like gunther sail..
    Weather or not your working sailplan is correctly sized greatly depends in the wheathers you do your sailing. Anyway to me it looks saileble.. and though the rig is a bit heavy the VCG and COE are louuuw:D
     
  7. sail.scow
    Joined: Aug 2008
    Posts: 18
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: New Zealand

    sail.scow Rrrrrrrrrrrrr!

    A staysail schooner allows you to set the fore masts aft shrouds lower and support the forestay, and takes a lot of complicated load out of the fore mast. The foremast has spreaders and an uppers.
    The jib stay, via the triatic stay, and the main staysail are tensioned by the main runners and main halyards combined.

    Could the main lose a little area? You lose the weight of the fore gaff, and hopefully a little more from the main gaff, if you shorten it. Then dropping the fisherman would be a lot easier than fighting thrashing yards and booms while reefing. Load on the runners is decreased also. The main mast has a forward shroud and a runner. No uppers or spreaders...

    Moving the fore staysail a bit helps with the reefing plan.You have more sail plan between the masts, so you can drop the fisherman first, then the jib, then the main staysail, leaving you with the main and fore staysail. After that you can decide on what configuration you want to fly for heavy weather and heaving to. Probably the reefed main and fore staysail would keep the boat jogging along, and put a final deep reef in the main, drop the fore staysail as the final step in reefing to keep the bow up...? Point is that there is just the main to reef now, and it only has two rows of reefing points.

    So your original mast partners remain, the rig gets much lighter, easier to reef, and easier to support. SA is roughly the same, CE is just a little higher and further forward but as each sail is reduced, the CE moves aft. Dropping the fisherman lowers the CE quite nicely. And the gaff main remains... A gaff schooner has a classic look of course, but a staysail schooner has its own appeal, with a photogenic cloud of (easily reefed) canvas set... There is also the golly wobbler which is an easy to set light air sail...

    Just some thoughts, but not too radical to carry out at your stage of the project.
     

    Attached Files:

  8. CT 249
    Joined: Dec 2004
    Posts: 1,709
    Likes: 82, Points: 48, Legacy Rep: 467
    Location: Sydney Australia

    CT 249 Senior Member

    What happens to the head of a gollywobbler on a reach or a run? Since it is still leading to a centreline sheeting point (mainmast head) doesn't it generate too much depth for efficient reaching, without a gaff or wishbone?

    Just curious
     
  9. sail.scow
    Joined: Aug 2008
    Posts: 18
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: New Zealand

    sail.scow Rrrrrrrrrrrrr!

    By golly

    A golly wobbler is just a convenient way to drape canvas over a schooner. Not really an efficient sort of sail like we have become accustomed to these days.

    I tossed it in while on the subject of photographic appeal.
     
  10. Glider
    Joined: Nov 2006
    Posts: 8
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Russia

    Glider Junior Member

    Thanks for your answers! I took timeout to think about it and I have few comments now.

    But what about fisherman's staysail? Is it effective without topmast?

    This boat will (hopefully) be doing offshore cruising. Like from Europe to South America to Australia. So, I would prefer to have a strong working sail plan with the possibility to add relevant amount of light wind sails.

    I'm in St.Petersburg. But I'm in the process of getting visa to Australia. Then I might finish the boat and... :)

    As far as I understand, it's the angle between mast and shrouds what matters? If I rake masts more but leave aft chainplates at the same position, the angle in the longitudinal (fore-and-aft) plan will remain almost the same. Or am I missing something?

    I was thinking about a boomed staysail. Even if I launch the boat with boomless staysail, I still might want to try it later, so I plan for it (considering COE etc.).

    Thanks for these ideas. I would like to stay with classic gaff schooner rig, but will consider these variants if original plan fails.

    sailplan2.PNG
     
  11. TeddyDiver
    Joined: Dec 2007
    Posts: 2,615
    Likes: 136, Points: 73, Legacy Rep: 1650
    Location: Finland/Norway

    TeddyDiver Gollywobbler

    1. They can be used simultanously. Fisherman's staysail is rigged from the top of the foremast so with foretop they have some overlap. In the main you have other topsail.
    2 (and 5) Three sails mentioned above +jibtop sail or a yankee and genoa (replacing your self-tacking staysail) maybe watersails and there's a lot of light wind canvas:D
    3. Not too far..
    4. Rake has a couple of advantages more. Boom head stays higher above water, heavy rig leaning backwards gives extra safety when (not if!) having trouble with running backstays, gaff hangs "of" from the mast easying hoisting and reefing
     
  12. Gilbert
    Joined: Aug 2004
    Posts: 525
    Likes: 5, Points: 28, Legacy Rep: 28
    Location: Cathlamet, WA

    Gilbert Senior Member

    Some years back I laid out the sailplan for a schooner and someone, I can't remember who, convinced me to have a boom on the fore staysail. They also convinced me the pivot point of the boom should be a ways back from the tack to allow the sail to set its best. They also convinced me that the pivot point should be on a track that slides forward to allow the sail to come down completely and there should be a line going aft which pulls the car forward on the track and also a downhaul for this sail leading aft for times when conditions are bad or sailing short handed. This way the sail can be muzzled very effectively without going forward.
     
  13. TeddyDiver
    Joined: Dec 2007
    Posts: 2,615
    Likes: 136, Points: 73, Legacy Rep: 1650
    Location: Finland/Norway

    TeddyDiver Gollywobbler

    Cars and tracks in schooner:confused: Don't say it got winches too:rolleyes: or aluminium masts ans spars:p
     
  14. KevinMcKee
    Joined: May 2005
    Posts: 7
    Likes: 1, Points: 0, Legacy Rep: 25
    Location: Port Townsend WA

    KevinMcKee Junior Member

    if you feel like you need more sail area you could always go with an overlapping forsail, Pride of Baltimore style. gives a good slot effect for the main, but makes tacking more work.
     

  15. Boston

    Boston Previous Member

    tacking with any overlap is a pain
    let alone if you've got a few of em to play with
    and that deck gets kind skinny up there in the wind
    but all in all its a beautiful rig

    Im looking at a friendship as a coaster and was thinking a storm sail set off the lowered gaff and the stay sail reefed would be my plan in tough times
    keeps that center of gravity down and means I dont have to play with all that canvas

    my two cents
    cheers
    B
     
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.