Conversion Westerly 22

  • 11 Oct 2018 20:43
    Reply # 6718465 on 6285145

    Yes, the seven panel sail, the third drawing, looks sound, sensible and seamanlike to me.

    The six panel sail would look better if the lower three panels were made wider - somewhere between the first and second drawings.

    Last modified: 11 Oct 2018 20:47 | Anonymous member
  • 11 Oct 2018 20:29
    Reply # 6718443 on 6285145

    That is a good point I think. The transitional panel with the altered angles doesn't look quiet right because of the luff width. After that I had the idea to just use 3 head panels. I scratched my head and couldn't find any cons then the more weight from the extra batten and the more work sewing another panel. But I bet that there is another drawback. If not I would go with the plan with 7 panels.

  • 09 Oct 2018 08:59
    Reply # 6714123 on 6285145

    Frank,
    With a low AR sail like this, I would certainly adopt a transitional panel, the third one from the top, so as to make the top two panels a little smaller. Try rotating the top sheeted batten by 10˚ or so, and the topmost batten by 5˚ or so. This doesn't affect the amount of batten stagger, but does even out the lengths of the leeches and the areas of the upper panels. 

  • 07 Oct 2018 12:39
    Reply # 6710668 on 6285145
    Now with the forthcoming winter we have done most of the epoxy work and did a final measurement of the mast position with the finished partners. Unfortunately the CE needs to be 30cm more aft compared to the first drawings. This gives a lower aspect ratio which I tried to compensate a little bit with wider lower panels because it looked a little bit inelegant and we'll have a too long pole anyway. The sail area would be 25m² which is 13% more than the original BR area. 


    So this could be some sort of final sail plan or at least we are nearly there. Does anyone have any concerns or would you do something different? 
    Last modified: 07 Oct 2018 12:40 | Anonymous member
  • 12 Aug 2018 20:38
    Reply # 6526156 on 6285145

    We are now nearly done with the mast step and partner. Not that bad for the first time I think.

  • 23 Jul 2018 20:45
    Reply # 6394348 on 6393609
    Anonymous wrote:

     A slightly heavier mast may help to soften the motion of the boat when at anchor. If the mast is too light it leads to a much jerkier action when at anchor. 

    The downside of a heavier mast is that it is more difficult to raise it. This could be a significant factor if your boat is trailed regularly and has to be rigged and derigged on a regular basis.

    All the best with the project, David.

    Thank you David! We don't want to trailer the boat that often. So that sounds good.


    Anonymous wrote:

    Have you any idea what the existing mast and rigging weigh? Your new sail will probably be lighter than the existing mainsail and genoa and you presently have a hefty boom (and maybe some poles).

    I think you are right. Never thought about to weigh the old mast, that would eliminate the concerns probably easily :)



    Anonymous wrote:

    Weaverbird, of similar size, has a 165mm/76mm x 3mm tapered tube for a mast, and (bare) it weighs 36Kg. In comparison, I weighed the old bermudan mast, including standing and running rigging and a furling headstay, and that was about 41Kg. So yes, the 177mm tube is just a little larger and heavier than strictly necessary, but not unduly so.

    When I converted Tystie from a ketch back to a sloop, the mizzen mast, which is 177mm dia, was passed over to Rob and Maren to use in converting Blondie to junk rig. She is only 21.5ft long, and she seems to be quite happy, so I think your Westerly 22 would be, too.

    Thanks again for your answer, David. I think we will take the pole and start building the mast step and partners ...


  • 23 Jul 2018 14:48
    Reply # 6393609 on 6285145

    Weaverbird, of similar size, has a 165mm/76mm x 3mm tapered tube for a mast, and (bare) it weighs 36Kg. In comparison, I weighed the old bermudan mast, including standing and running rigging and a furling headstay, and that was about 41Kg. So yes, the 177mm tube is just a little larger and heavier than strictly necessary, but not unduly so.

    When I converted Tystie from a ketch back to a sloop, the mizzen mast, which is 177mm dia, was passed over to Rob and Maren to use in converting Blondie to junk rig. She is only 21.5ft long, and she seems to be quite happy, so I think your Westerly 22 would be, too.

  • 23 Jul 2018 08:33
    Reply # 6393129 on 6392644
    Have you any idea what the existing mast and rigging weigh? Your new sail will probably be lighter than the existing mainsail and genoa and you presently have a hefty boom (and maybe some poles).  These should cancel out the weight of yard and battens.  So I would reckon if your present mast and rigging - including bottle screws - is within 10kg of the heavier option, you'd be laughing.  Only my opinion - I'm no engineer.
  • 22 Jul 2018 23:41
    Reply # 6392778 on 6285145

    Hi Frank,

    it depends to some extent what you will be doing with the boat. A safety factor of 3 is good and recommended for boats that will be going offshore and may be subject to harder use. A safety factor of 2 is about as low as I would recommend in any circumstances. Remember that if caught in a following gust stress on the mast can significantly exceed the righting moment forces.

     A slightly heavier mast may help to soften the motion of the boat when at anchor. If the mast is too light it leads to a much jerkier action when at anchor. 

    The downside of a heavier mast is that it is more difficult to raise it. This could be a significant factor if your boat is trailed regularly and has to be rigged and derigged on a regular basis.

    All the best with the project, David.

  • 22 Jul 2018 21:02
    Reply # 6392644 on 6285145
    We have now a quote for the mast. First we were up for a 144/76 tapered 3mm aluminum flagpole but its not available from the distributor right now. So they send us a quote for a 177/76 4mm aluminum pole. The price is okay i think but its probably to hefty for our small boat. The W22 has a righting moment from maybe 700-800 kpm and the pole a breaking strength from 2530 kpm and weights about 43kg.


    Unfortunately there isn't very much data in the mast database for this specific scenario. Now it's doubtful for us to get this mast and be happy with the high safety factor or organize a thinner one with a weight under 35kg. What do you all think?

    Frank




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