Forgot password

peregrine's rig?

<< First  < Prev   1   2   Next >  Last >> 
  • 27 Nov 2011 17:46
    Quote
    Reply # 760646 on 754983
    Anonymous member

    David,

    If you wanted to make an already fast hull to go fast and close to the wind, would you choose a split junkrig or a wingsail a la Tystie? I have tracked down an X-99 with a blown engine and in the right state of neglect. Unfortunately the price is not right, but I will give an offer. My intetention is to compete and to turn a few heads + give some lessons in easy boathandling, as I know that sailing with a junksail gives you a new lease of life sailwise. Being a lazy sod, I can now plan to sail well into my seventies, health permitting.

     
  • 27 Nov 2011 04:46
    Quote
    Reply # 760412 on 754983
    Deleted user

    David,

    Are the fan shaped sails you are drawing now based on the proportions which had been published a few years ago in an article by yourself in the JRA Journal? When I drew a sail to these proportions a couple of years ago I ended up with quite long batten lengths for a sail to match Footprints rig. I have had a look at the drawings of the sails you did for Annie Hill and the 80 sq.m sail and I like the steep yard angle and the fact that the yards are shorter than the batten lengths which would mean a lighter yard. The square top shape on the 80 sq.m sail also looks good. David

     

     
  • 26 Nov 2011 19:49
    Quote
    Reply # 760208 on 754983
    Deleted user
    Thanks for those comments. I look forward to our Northern Rally in March when I may get the opportunity to see these different rigs in the flesh. In the interim I will draw up some sail shapes. Its great to have access to these informative forums. 
  • 26 Nov 2011 19:34
    Quote
    Reply # 760201 on 754983
    Anonymous member
    David,
    I think (but I can't prove without boat-against-boat trials) that with my wingsails, I get the most performance possible with a junk rig based sail, with all the handling advantages as well. But I fully accept that there is a high cost to be paid, in many different areas, as you suggest.
    The main thing that makes it undesirable for you to go for the wingsail, I think, is your need to reduce weather helm on the run. This can be done easily (in a normal junk rig, but not in a wingsail) by moving the boom across the mast, using a running line with one end attached to the middle of the boom, and the other end to the tack, as I did with Tystie's single sail. Whether you use a HaslerMc/Cleod or a fanned planform, the aspect ratio must necessarily be low, with Footprints' short mast, and I feel that you should rig this line whatever planform you decide upon – but the fanned planform is clearly superior, I think, when the aspect ratio is low. Some boats are sensitive to having too much sail out to one side. Tystie was, and it seems that Footprints is, too. On the other hand, Fantail seems to steer well downwind without moving the sail across, perhaps because she has more balance area in the sail already.
    Sailing alongside Fantail yesterday, I could clearly see the camber developing in the fanned, but flat-cut, top of the sail; and I would advocate a sail of this type for Footprints, with 6% camber in the lower panels. I think it will give you what you are looking for, without the investment in time, skill, money and continued development of the wingsail.
  • 26 Nov 2011 10:56
    Quote
    Reply # 760013 on 754983
    Anonymous member

    Thanks everyone for the wealth of knowledge.  Before I set about digesting I will get a book,  need to get my head round this a bit.  As for the falmouth punt, on reflection I have decided the draft would be an issue and am following a couple of shallow draft long keelers.

    Cheers
  • 26 Nov 2011 00:32
    Quote
    Reply # 759745 on 754983
    Deleted user

    Gents,

    I have been reading your exchange with much interest. I am currently pondering a new sail for 'Footprints'. Her current sail based on the Hasler/McLeod pattern is now 14 years old and will soon become unreliable, and I want to gain that extra bit of performance to windward. David Tyler very kindly designed the batten shape for a soft wing sail to suit 'Footprints' but because of a new house build project for the past 18 months I have not as yet done anything about this but I will/ need to be building the new sail next year. Footprints sails well on a reach and downwind with very good boat speed although with quite a lot of weather helm. Up wind she lacks power although sails considerably better with the mast on the leeward side of the sail providing up to an extra knot of boat speed on this tack compared to performance on the starboard tack with the mast to windward. Footprints is 10 metres over all with the halyard attached to the mast 10.4 metres above deck so any rig will be of a fairly low aspect. What I am after in my new sail is: Improved performance to windward; a reduction in weather helm; reduced weight over the current very heavy sail; simplicity and reliability including simplicity of construction; and a sail suitable for coastal sailing in the sometimes boisterous sailing conditions we get in New Zealand. 

    I will be interested to hear David's comments on his sails after his voyaging of the past 18 months since he was last in New Zealand but obviously his rig has done him well for all the miles he has sailed. So the questions I am pondering are:

    • While the soft wing sail will give me all the improved sailing performance I desire and reduce weight in the rig it is also going to be quite a complex sail to build and possibly maintain in the longer term as it will not have the simplicity and robustness of a fixed batten sail. There also some issues to overcome at the top of the mast.
    • Do I need to go to the complication of a soft wing sail when a well designed fixed batten sail could well provide all the benefits I am after bearing in mind that we do not race our boat.
    • I do not know that a fanned sail will be the answer as I suspect that the CE may end up too far aft and not help the weather helm situation.
    • I have been looking at the photos of Peregrins sail and thinking that a cambered panel sail similar in design to hers could be an answer especially because I could use my existing battens which are cedar and unidirectionals and which provide light weight along with stiffness. By building a more intelligent composite yard rather than a solid chunk of wood and using a lighter sail cloth than the current sail (15 oz)I can probably also save some weight. I would also maximise sail hoist to provide as much sail area and luff lenght as possible. A sail such as this will be a lot less complex to build and if I can gain that extra knot of boat speed on the mast to windward tack, plus maybe a little bit more windward performance I would be a happy man.

    So I would be interested to hear any comments regarding the 'Footprints Design Challenge'.

    David Thatcher
  • 24 Nov 2011 23:59
    Quote
    Reply # 758967 on 754983
    Anonymous member (Administrator)

    Stavanger, Friday

    David.

    Thanks for your explanation of the fanned sail. I notice that our rigs have more in common than I knew before:

    STEEP YARD ANGLE: Both rigs use high-peaked yards. I too could have gone steeper, but have stopped at 70° to give about the balance I find practical to use.

    YARD HAULING PARREL: On Johanna’s sail I too have fixed the yard hauling parrel higher than the halyard (30-40cm?) to get better peaking up of the yard (against the sheet forces).

    LUFF HAULING PARREL: The Yard h. parrel works against the luff hauling parrel which is only attached to the yard and batten no. 3. With the sail fixed with these two parrels, the sail below is less prone to moving forward or aft.

    HONG KONG PARRELS (yes, used by the Chinese in Hong Kong) versus convex luff: I’m not so afraid of the HK parrels: As long as they don’t need to go far aft of the mast and rob the camber, and I don’t have to look after them, they are OK. If you manage to hit the right rounding of the luff to prevent diagonal creases – and without fiddling with extra luff h. parrels, then good!

    FLAT VERSUS CAMBERED TOP PANELS: I’ve found that my moderately cambered top panels are very well-behaved, even in a blow and have never felt any need to go back to flat panels there. However, I can see the point of having perfectly flat top panels on a typical deep-sea traveller (Fantail??). I hope then that you find a way to create camber through twist, the way Vincent Reddish described many years ago. It would be a shame to lose the drive of the top section in light winds. I hope to hear more about those smart sheeting tricks. I also hope to hear what running parrels you eventually settle on in Fantail’s rig.

    Good luck, rig-fiddling is fun!

    Arne

    Last modified: 25 Nov 2011 00:04 | Anonymous member (Administrator)
  • 24 Nov 2011 21:25
    Quote
    Reply # 758895 on 758142
    Anonymous member
    Arne Kverneland wrote:

    David,

    It seems that we are talking past each other.

    Now, at least we agree that some camber, somehow should be put into the panels to improve drive, both in Hasler-McLeod style sails and in fanned junk sails. My simple question is then:

    What makes you think that a fanned sail is an improvement over the HM sail?

    Handling? Performance? Looks? How come?

    Arne.

    Arne,
    We agree that some camber, somehow should be put into the panels of the lower two thirds of the sail.
    My point is that attending to the planform of the upper third of the sail radically improves performance there, where we would like to retain flat panels, for docility, but we would still like to have some camber, for best performance when the lower two thirds of the sail has been reefed away.

    In my opinion:
    1. the yard should be steeply angled. It is possible to make the angle between the yard and the line of the luff, extended, 10 degrees - if the yard parrel is attached to the yard above the halyard block, and if the luff is a little convex, with the luff hauling parrel in the right place. This is a bit extreme for all except performance-oriented sailors, and I'd advise 15 degrees as the steepest practical angle for cruising sailors.
    2. the yard should be short, so that the leech of the top panel is as near horizontal as possible. Pointy-topped sails are not as efficient as square-topped sails (look at the square-topped mainsails of the more extreme race-boats).
    3. the top two battens should be steeply angled. 
    4. there should be some rounding on the head of the sail, a maximum of about 2% of its length, so that the centre of the sail is not "starved" when the yard bends (as it does).
    Given these four factors, camber can develop in the top three panels, which otherwise cannot happen - at least, not so much, and not so easily.

    Then it is a question of making a transition between the top, fanned part of the sail and the lower, cambered panel part of the sail. This seems to be best achieved by a little gentle fanning of all the lower battens. It doesn't have any affect on performance, but it does improve the looks, and the practicalities of making the sail. Very careful design work is needed to ensure that the battens stagger aft by an acceptable amount. It seems to be best to have a convex luff, not only to reduce the loading on the luff hauling parrel(s), but also to enable a straighter leech, to ensure minimal sheeting hang-ups.
    The sail that I drew for Fantail doesn't carry these ideas to extremes, since Annie is  not a performance-oriented sailor. However, I do believe that it has given Fantail very good performance for her size, without having to crowd on any more canvas than the bermudan boat has.

    In the Box online file storage, 'drawings', 'david's doodles' is the 80 sq m sail that I proposed to Sebastian for his new sail, which he didn't adopt. It shows al the features I'd like to see, in a more extreme form than in Fantail's sail.

    Finally, it's no accident that the traditional, offshore chinese rigs have fanned sails. A couple of thousand years of development taught those guys a thing or two, and we need to learn from them.

    David.
    Last modified: 24 Nov 2011 21:33 | Anonymous member
  • 23 Nov 2011 21:55
    Quote
    Reply # 758142 on 754983
    Anonymous member (Administrator)

    David,

    It seems that we are talking past each other.

    Now, at least we agree that some camber, somehow should be put into the panels to improve drive, both in Hasler-McLeod style sails and in fanned junk sails. My simple question is then:

    What makes you think that a fanned sail is an improvement over the HM sail?

    Handling? Performance? Looks? How come?

    Arne.
  • 22 Nov 2011 19:25
    Quote
    Reply # 757098 on 754983
    Anonymous member
    How do you compare apples with oranges, or carrots, or mushrooms?
    Unlike the "pointy-people", we sail a range of very different rigs on a range of very different boats - and long may it continue. 
    It would be unfair of me to condemn Johanna as being unfit to sail offshore, on the basis of the snapshot of a short sail on a fjord. It would also be unfair to similarly condemn Tystie, on the basis of a similar snapshot. Tystie's single sail had very little camber in the lower panels, and was never going to be a sparkling performer in light winds and sheltered water, unlike Johanna. However, the rig proved to be entirely suitable for knocking around in wild places in rough weather. Horses for courses.
<< First  < Prev   1   2   Next >  Last >> 
       " ...there is nothing - absolutely nothing - half so much worth doing as simply messing about in junk-rigged boats" 
                                                               - the Chinese Water Rat

                                                              Site contents © the Junk Rig Association and/or individual authors

Powered by Wild Apricot Membership Software