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Introduction - masts - sails

  • 10 Jan 2013 01:00
    Quote
    Reply # 1175842 on 1174887
    Deleted user
    Hello Adam and Kristof,

    We, too, are renovating a Gazelle here in Virginia (USA). We are almost 
    finished, save for an electric drive installation. We went with alloy masts 
    that were industrial light poles in the typical Colvin shorter-foremast 
    schooner design. Plus, we wanted the fun bow pulpit.

    Our rigs are a bit different, I think, the way you described not having a 
    bowsprit. Does your mast placement look like this guy's?

    http://www.yachtworld.com/core/listing/photoGallery.jsp??access=Public&listing_id=1636&units=Feet&checked_boats=1446948&boat_id=1446948&imc=pg-fs&back=boatDetail.jsp&boat_id=1446948

    Our main is a bit further aft and our fore is quite a bit further aft. Its 
    good that you have the old sails, though. You can measure their areas,
     and with the mast placement, you can get the baseline sail balance 
    down and then improve from there. Well, as your project goes 
    forward, fire any questions down this way. Can't wait to see some 
    pictures and hear how the steel is treating ya.

    Oh, I have a lot of measurements on my profile

    Ciao

    John & Suzy
    Last modified: 10 Jan 2013 01:01 | Deleted user
  • 09 Jan 2013 11:16
    Quote
    Reply # 1175145 on 1174887
    Anonymous member (Administrator)

                                                                   Stavanger, Wednesday

    Hi Kristoff and Adam

    You seem to be lucky to have found a sound Gazelle - and without the rig. An American sailor who once cruised in company with Colvin himself, told me that Colvin’s boat was just painfully slow. I hope the new rig of Zebedee will inspire you to make something better.

    Now, with two masts and sails there is the problem of getting enough room for sheeting the sails, in particular the foresail. When designing my only schooner rig for a friend’s boat, the 49’/23ton Samson, way back in 1993, I got a bit greedy and tucked the sails too close to each other to get enough sail area. (..have a look at the last page of this write-up...). Samson sails all right, but tacking has always called for some care with respect to handling the foresail sheet(s). I dear say that 90% of all the rig fiddling done to that boat has been to that sheet. Last summer the owner took the trouble and moved the foremast about 60cm forward and increased the rake a bit.

    Still, sheeting the foresail will always be a challenge, so be prepared to sheet that sail to a track going almost from rail to rail. The point is to avoid the steep sheeting angles which lead to such high forces.

    Good luck!

    Cheers, Arne

    PS: Step one is to move the fore-mast as far forward as possible. Getting the balance right is a challenge without the jibs.

    Last modified: 09 Jan 2013 11:20 | Anonymous member (Administrator)
  • 09 Jan 2013 05:54
    Quote
    Reply # 1174969 on 1174887
    Anonymous member
    Hello Kristoff and Adam, and welcome to the JRA. That's a sizeable job you've taken on, to re-rig a Gazelle.

    I have never liked the rig of the Gazelle. It is neither western nor chinese, neither one thing nor the other, and it seems to fall between two stools, not succeeding in gaining all the advantages of the chinese rig, nor all the performance of the western rig. The only time I've sailed alongside a Gazelle, beating out of Juan de Fuca Strait against a big sea, I was going twice as well, in a smaller boat. Since your boat has no bowsprit, and free-standing masts, I'm guessing that she was never rigged to the original Colvin sailplan, so it would be good if you could find out exactly how she was rigged, and find a photo or two, if you are in touch with the previous owner.

    If she had two identical masts, it's a reasonable bet that she had two identical, or near identical, sails. Even starting from a point of not knowing whether that was so or not, it's what I would suggest as being the most sensible rig for you. To get an idea of what it looks like, go to 'JRA magazines' in the menu, and download the last issue, issue 60 ( I would recommend the 13MB landscape edition). Look for the article about Ti Gitu, a 40ft steel boat with two 500 sq ft sails. Also look at Hestur and Badger, two 34ft Benford dories, each with two almost equal size sails.

    You're going to need to buy 'Practical Junk Rig', the book that is regarded as an essential reference for everyone who builds a junk rig. You can get it from Amazon. In it, you will find all you need to know to build the style of junk rig that has been the most prevalent in Europe for the last 50 years. There is nothing in it which is absolutely wrong, though we have made some advances in design and construction since it was published. You'll need to work through the section on rig design to work out whether the masts are in the right place, and what kind of sail area you'll need, and how it needs to be distributed for hull balance.

    To start to learn more about the later developments, Arne Kverneland's writings, in the 'Junk Info' section of the menu, will give you a lot of insight into the kind of rig that I think you should be building. That is, to a planform slightly improved over that recommended in 'PJR', and with some camber sewn into the panels of the sails, using a fairly straightforward method suitable for a first-time sailmaker.
    Last modified: 09 Jan 2013 06:10 | Anonymous member
  • 09 Jan 2013 05:37
    Quote
    Reply # 1174965 on 1174887
    Anonymous member
    Tom Colvin's junk rigs are a bit different as you probably know, having stayed masts and a jib set off the bowsprit.  His masts are usually alloy and much skinnier than unstayed masts It sounds like a previous owner has chosen to put a Hasler style unstayed tig in the boat, hence the 10 inch timber masts.  I prefer an unstayed rig, though I stress I have no experience of sailing with a Colvin rig.  I have heard others complain about the sails pressing against the rigging, but if you came beam on when reefing this should be less of a problem.  I tend to do that with my unstayed rig anyway as it all goes much more smoothly when you can feather the sail.  I have a cambered sail on my boat which dramatically increases the windward performance and makes for quicker tacking at sea but it is more complex to set up.  After six months trial and error I have pretty much got it to the stage where it behaves itself.  Flat, or flattish sails might be ok for long distance sailing, but if you were going to be doing more coastal cruising then the cambered sails are worth looking into.  I have an alloy mast imported into Australia from France, 200mm (8 inches) at the base to 110mm (4.5 inches) at the truck, with a 5mm thick wall, 10.5 m from heel to truck (about 35 feet),  setting a 35.6 sq m sail (Just over 400 sq feet I think), and the mast is very stiff.  Good luck!  The Gazelle is good design.
  • 09 Jan 2013 03:42
    Quote
    Message # 1174887
    Deleted user
    Hello,

    I'm Kristoff. Me and my best friend Adam bought a 42' Colvin Gazelle (a junk rigged schooner) last spring and are giving it some major TLC to one day sail the seas. It is a steel hull with functioning electric systems, the plumbing is in the midst of being redone; point is, the boat floats and is mechanically sound.
    The MAJOR projects ahead of us are designing and building/buying new masts, designing and making our own sails, and rigging the boat.

    When we purchased her she had masts, sails, rigging, all in rather dire condition.

    So we have a steel hull and are looking for insight and guidance on how to go about designing the sail plan, masts, and rigging of our boat.

    Colvin offers sail plans for his rigs, which we have copies of, however consideration is to be made given that our boat does not have a bowsprit of which all his plans do.

    We could of course simply copy the sails that came with the boat but with a little education we're confident we can improve performance.

    As for the masts, they were unstayed solid douglas fir. Replicating them is pretty much the plan, although their height at this point is not clear. When we bought her the masts were identical at 40' top to bottom and 10.5" in diameter (Imperial. I know... we're still in the dark ages over here...)

    Basically, insight into how to make a sail plan and figure mast height is a major block we are having right now. We have literature in the mail coming from Tom Colvin. If there is anyone reading this that has his or her own insight we would be most appreciative.

    Thanks for reading!
       " ...there is nothing - absolutely nothing - half so much worth doing as simply messing about in junk-rigged boats" 
                                                               - the Chinese Water Rat

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