Split Junk Rig on Westerly Windrush

  • 25 Mar 2013 22:06
    Reply # 1251592 on 1251027
    Chris Gallienne wrote:Annie, it is a source of continuing frustration to me that piano manufacturers persist in ignoring recent developments in westernised Chinese lids.

    I know - pathetic, isn't it? :-)

    David has suggested that I follow your choice of a hybrid aluminium/wood mast, which seems an attractive proposition. What wall thickness did you use on the aluminium section? And are you still satisfied with your choice?
    I am more than satisfied - I'm delighted with my choice.  Quite apart from anything else, it meant that I could paint my topmast a fetching shade of aqua, which I think adds a lot to Fantail's appearance. 

    According to what I put in my Profile ( ;-} ) the alloy's spec is
    UA6084 152.4 x 5 tube 6261 T6 6m.  The Great One reckoned I could have got away with something a bit thinner - 3.5mm from memory  David may well want to come back on this one as he is The Expert.  I might add that your sail area of 312 sq ft is identical with Fantail's.
  • 25 Mar 2013 12:55
    Reply # 1251117 on 1248976
    Deleted user
    Arne
    Thanks for your advice .. I'm certainly not keen to build any more mast than I need.

    Nice pictures, by the way - you clearly have both a better camera and a better eye than me!
  • 25 Mar 2013 11:08
    Reply # 1251063 on 1248976
    Anonymous member (Administrator)

    Stavanger, Monday

                         ..mast length, the limiting factor...

    I guess I am a little late to enter this discussion, but so be it:

    Over the years it seems that I have gained a reputation for liking big sail areas. True enough but remember; while I am generous with sail areas, I am restrictive with mast lengths. My view is that reefing the sail is piece of cake while reefing the mast under way is impossible. This is a major reason why I use the HM sail type with 70° yard angle: I get the biggest sail of any JR shape for a given mast length and chord.

    Let us compare Poppy’s and Johanna’s rig for a moment:

    Poppy: LAP= 11.28m, Chord ~5.9m, SA=47.5sqm

    Johanna: LAP= 9.6m, Chord ~ 5.7m, SA= 48.4sqm.

    The difference in LAP is as much as 1.68m. Now, Johanna’s sail could well use a 20cm taller mast and Poppy’s mast may well be 20cm shorter for her sail, but even so there would be room for fitting another panel of HM sail onto a Poppy mast.

    This is what Ketil did to his Marie G: With her LAP of only 10.7m Ketil now hoists 8 panels or 55sqm.

    Well worth considering, at least if one has offshore sailing in mind.

    Cheers, Arne

    Last modified: 26 Mar 2013 17:10 | Anonymous member (Administrator)
  • 25 Mar 2013 09:03
    Reply # 1251027 on 1250828
    Deleted user
    Annie Hill wrote:
      a grand piano with its lid up will sail downwind!

    Annie, it is a source of continuing frustration to me that piano manufacturers persist in ignoring recent developments in westernised Chinese lids.

    David has suggested that I follow your choice of a hybrid aluminium/wood mast, which seems an attractive proposition. What wall thickness did you use on the aluminium section? And are you still satisfied with your choice?
    Last modified: 25 Mar 2013 09:06 | Deleted user
  • 24 Mar 2013 23:40
    Reply # 1250828 on 1250552
    Chris Gallienne wrote:
    To be fair, off the wind, and with insufficient wind to justify reefing, the rig performs quite well.

    As someone once unkindly said of a 'character boat', that went downwind nicely - a grand piano with its lid up will sail downwind!

    Last modified: 24 Mar 2013 23:40 | Anonymous member
  • 24 Mar 2013 16:18
    Reply # 1250552 on 1250456
    Deleted user
    Slieve
    You may be right about questioning the need for extra sail area over the standard layout - the feeling of being undercanvassed may well be down to inefficiencies in other areas. If I was able to reduce the size of the rig the problem of placement would also probably ease somewhat.

    To be fair, off the wind, and with insufficient wind to justify reefing, the rig performs quite well. Close hauled, the problem is severe enough to completely prevent me from passing from North to South through St Georges channel last year with a not very strong tide running against me. I suspect the main is old and tired enough to have lost some shape. The problem is, since I acquired the vessel, I have had little opportunity to observe it's behaviour under full sail, and with the weather helm the first reef is always in the main. I have considered adding a bowsprit, as I know an owner of a W22 has done with some success. This would still require some re-cutting of the No 1 Genoa, I think. Once the weather improves I will take her out and pay particular attention to the shape of leading third of the main.

    However, new mainsail or bowsprit, if I am to invest in significant changes to the rig I would still be keen to replace it with a junk rig. The advantages unrelated to performance are significant to me, not least the ease of single-handed sailing. I also have longer-term plans for a larger boat with junk rig, and would welcome the chance to evaluate it and familiarise myself with it on a smaller vessel before I take these plans further.

    Thank you for taking so much time to consider my questions. Doubtless I will return with more once I have digested the suggestions you and others have kindly made.

    Chris
  • 24 Mar 2013 16:01
    Reply # 1250546 on 1250339
    Deleted user
    David Tyler wrote:
    May I recommend the approach that Annie took with Fantail - an aluminium tube 6" x 3/16" wall ( 150mm x 5mm), as long as you can get it from a stockholder, with a wooden topmast? This works out well, and saves cost and space inside the boat.


    David, thank you for that suggestion - I have been considering a 150mm Aluminium section and welding a taper in the upper part, but was worried about the effect on strength.

    Your suggestion seems to be a good one, with a parallel-sided aluminium tube and a tapered wood top section - I will look into this further.
    Last modified: 24 Mar 2013 17:45 | Anonymous member
  • 24 Mar 2013 12:42
    Reply # 1250456 on 1248976

    Hi Chris

    I’m taking my data from ‘The Westerly Story’ which I have as a member of the WOA. I have some experience of the smaller Westerlys, having owned a Longbow and a Konsort, and taught RYA courses on Fulmars, Centaurs and Conways. With this background I think I can safely suggest that you do not need to increase the sail area above the 312 sqft of the full main and No.1 Genoa. With a shallow draft at 2’6", a narrow beam of 7’5" and a ballast ratio of about 33% you have a fairly tender hull. At one foot longer and nearly a tonne heavier, the Centaur has a 3’ draft, 8’5" beam and 42% ballast ratio and 384 sqft with main and big Genoa, and performs quit well on that. With the split junk the area seems to be more efficient, so you get more drive on all points of sail. I have never felt any lack of sail area on Poppy, getting 2 knots in any direction in 4 knots of true wind.

    Don’t forget that the standard rig has an overlap of the Genoa on the main, and when that is spread out without the overlap it starts to look very big. Poppy’s sail does look big even though it is standard fore and aft area. I know Arne always suggests large area, and I respect his views, but he also sails boats with decent keels and ballast ratios, and that is something you do not have. Edward, with his lively Splinter Amiina, is finding full main plus Genoa quite ‘interesting’ with the split rig power on a tender hull (probably when compared with his last junk rigged boat which I believe was not over canvassed).

    You say your Windrush is "ponderously slow, and won't point, and reluctant to tack" and "has quite a lot of weather helm under full sail", so what you are really saying is that you have a real challenge on your hands to improve things. I agree that the standard Westerly rig reefing kills the marginal performance, and is a pain to use, so a conversion to the split junk could be a good idea. The problem is to work out the best place for the mast.

    A slow boat with inefficient keels will be unlikely to point particularly well, but the reluctance to tack and the weather helm make me question the camber shape and condition/ age of your existing sails. Are they old? Has the camber/ belly been blown aft so that the maximum camber is positioned about 50% or greater? It’s hard to see this on the Genoa, but it might pay to draw a ‘camber line’ across the sail and lying on deck to take a photograph looking vertically upwards. (Stick a line of black electrical tape across at about 35% height) Can you ask any Windrush owners with new sails how well they tack and what the weather helm is like? Unfortunately there are no ‘Boatline Members’ listed for the Windrush in the WOA, and I haven’t been able to catch the W22 member on the phone yet.

    Since writing the above I’ve spoken to the W22 Boatline Member, Nigel Phillips, and learned quite a lot. All the questions I asked above are still relevant. Apparently some owners move their forestays forward to help the balance, and as well Nigel has transformed his boat's performance including to windward with new Arun sails. If pushed I could have a word with Ivan at Arun to see what he did with the design of Nigel's sails.

    So far I have been lucky with mast placements for split junks and the few boats have reported good balance, so I am starting to wonder if the rig is fairly tolerant to mast position as the drag and drag angle are low.

    I must go now, but there’s a lot to think about,

    Cheers, Slieve

    PS. Taking a photo of the Genoa camber is a good trick for any roller Genoa, even a new one, as it shows just how inefficient a roller Genoa actually is.

    PPS. By the way, my new boat has carbon main structure tying the deep carbon fin with its encased lead ballast bulb to the mast step and partners, and good hoop strength around the mid sections. The ends are particularly light. The carbon mast and spars are remarkably stiff, yet the battens have a little give in them.

    Last modified: 24 Mar 2013 12:49 | Anonymous member
  • 24 Mar 2013 03:14
    Reply # 1250339 on 1250251
    Chris Gallienne wrote:
    If a fat hollow wooden mast is not part of the right answer, presumably you would recommend a smaller aluminium section? Maybe in a tabernacle?
    Chris,
    May I recommend the approach that Annie took with Fantail - an aluminium tube 6" x 3/16" wall ( 150mm x 5mm), as long as you can get it from a stockholder, with a wooden topmast? This works out well, and saves cost and space inside the boat.

    A wooden tabernacle is possible, but adds back in the volume that you just saved by going to an aluminium tube. However, if you are an engineer, the "hinge and sleeve" joint above deck level is a possibility.
    Last modified: 24 Mar 2013 17:46 | Anonymous member
  • 24 Mar 2013 00:34
    Reply # 1250267 on 1248976
    Deleted user
    That makes a lot of sense, and that's pretty much where I would have placed it if the hatch wasn't there.

    I guess I need to think about this a little more.....

    What did you use for your 150mm mast on Poppy, by the way?

    Chris
    Last modified: 24 Mar 2013 00:35 | Deleted user
       " ...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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