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Help with a Sailplan for a wooden classic / Francis Herreshoff Buzzards Bay 14

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  • 06 Jun 2017 23:38
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    Reply # 4884057 on 4497913
    Anonymous member

    Dear All - just to keep you posted, 3 or so months later when Francis floated or took a flight with her new Aero Junk Rig...  

    After few months of relentless hard work and with much help from the JRA  members in New Zealand my boat, was ready for its junk rig launch.  The mast was stepped and the sails raised on 21 May 2017.  Pete Hill, put much of hard work in the last 3 months designing her rig, building the top mast, aero junk rigging and just about everything that goes with it. The moment she took off the pontoon (literally) we both livened up looking and feeling like two young kids taken for a first dinghy ride. Pete said:


    The winds were light but it was sufficient to see how the rig worked. You would expect a Francis Herreshoff design to sail well and Francis with her new rig performed even better than expected. The rig was almost perfectly balanced with just a touch of weather helm and steering was fingertip light. She seemed fast in the light winds, pointed high and tacked on a sixpence. There were a lot of big smiles all round on that day. Much more testing will need to be done in varying conditions to evaluate the rig properly.

     

    We had only one sunny afternoon to sail her before packing her off for the winter and sailing off to Polynesia. However, I will be back to sail her extensively next season. She will be having a lot of fun on the waves and in the calms around New Zealand coastline with us.


    Photos

    For those who might be interested here are some technical details:

     

    7% lead (not taking the rudder into account)

    Sail area  16.72 sq. metres, with the jiblet being 26% of the total sail area

     

     

    LOA 5.63m 18’ 6”

    LWL 4.69m 15’ 5”

    Beam 1.90m 6’ 3”

    Draught 0.76m 2’ 6”

    Displac. 770kg 1700lbs

    Ballast 363kg 800lbs

     

    Mast length 7.5m overall, 6.5m above partners

    Lower mast: 100mm diameter, 3mm wall thickness, 6m aluminium (6060 T5)

    Top Mast: Oregon Pine (Douglas Fir), 2.5m (solid)

    Mast weight 25Kg

    Battens & Yard 10kg

    Sails 8kg






  • 22 Feb 2017 20:51
    Quote
    Reply # 4627022 on 4497913
    Anonymous member

    Hi David and Rob, 

    Yet another long gap in getting back to you as Pete and I are working flat out on battens, mast and sail plan so not much time for online 'chat'.

    No blame to anyone but a big credit is definitely due! 

    Turning up for AGM is touch and go as it stands now but we are giving it our best shot. 

    Ahoy
  • 17 Feb 2017 22:30
    Quote
    Reply # 4615409 on 4497913
    Anonymous member

    Hi Linda,

    You always fancied an Aerojunk and now you are going to have one! Very pleased for you and delighted to hear that you have a expert right at hand. David Webb plans to get Little Gypsy Girl fitted with an Aerojunk rig for the AGM junket - will we see Francis sailing there as well?

    Rob


    Last modified: 17 Feb 2017 22:31 | Anonymous member
  • 15 Feb 2017 07:10
    Quote
    Reply # 4609934 on 4497913
    Anonymous member

    Hi Linda,

    thanks for the credit, hopefully it will all work out well and not turn into blame!!

    When I looked at all of the plans, proposals etc it just seemed obvious to me that the Aerojunk met the criteria and would be achievable with the minimum of change and work in the existing boat. It would also be possible to use a shorter mast than the other proposals without loss of performance.

     I hope that it all works out well. David.
  • 15 Feb 2017 06:32
    Quote
    Reply # 4609892 on 4497913
    Anonymous member

    Dear All 

    Apologies for silence. Francis went into the water and there was a lot of unnecessary nursing her! She is now on her mooring and we are back to work.

    Thanks so much for your comments. It appears that the leads are very small. For keeping the mast in its original position it seems obvious to use a well balanced sail.

    Had it not been for David Webb's advice I probably would have not consider it - and Pete did not suggest it outright. But I really like aero junk especially because I sailed it for 800 miles and was very impressed by it. Also it will fit very well within all the constraints. 

    I made up my mind and went for the aero junk. Would love to hear your comments, since it has not been east to come to a decision. 

    Thanks again for all the effort put into discussing and designing the best possible option. It has been a very interesting and valuable experience.   

    The battens are in a process of being made, all the material has been ordered and Pete is hard at work! ...Francis's Final Rig

    Keep you updated with the progress. 

    Ecstatic Linda !
  • 12 Feb 2017 10:52
    Quote
    Reply # 4605129 on 4497913
    Anonymous member (Administrator)

    I buy Ted Brewer’s points, but would like to add a couple more:

    A small transom, indicating fine lines aft:
    This lets one heel the boat over without getting increased weather helm. The Buzzard Bay 14 appears to be such a     well-balanced hull, just as my 29’ Johanna was.

    (With her full bow and fine stern, Johanna could easily be sailed to windward with 30° heel, and little rudder input)

    The other factor is size:
    On a small boat like this, the rudder is relatively huge, and even if the keel is ‘long’, it is still not very long, so the rudder is not buried in a very thick boundary layer. Just imagine when looking at that boat‘s profile, that it was a 40-footer: The rudder would then look abnormally big. If this little 17-footer needed 3 or 6° rudder input, I bet most would say that it was well balanced. Try to hold a 40-footer’s rudder at those angles, and it would soon feel tiring.

    Cheers, Arne

    PS: Paul J Thompsonn fixed the weather helm problem on his La Chica by fitting a new, better rudder further aft. Has he written an analysis anywhere about that, apart from reporting big improvements?
  • 12 Feb 2017 08:48
    Quote
    Reply # 4605064 on 4497913
    Anonymous member

    In Ted Brewer Explains Sailboat Design, he gives this list of factors shortening lead:

    • Short keel
    • Deep draft
    • Narrow beam
    • Stable hull
    • Fine forward waterlines
    • Low aspect rig
    • Two-masted rig
    Possibly the two that apply here are narrow beam and fine forward waterlines, but these are offset by some of the other factors. I think I still incline towards putting the mast step in the original position, raking the mast forwards as far as is practicable, and using a sail planform that can tolerate an adjustable balance area. 
  • 12 Feb 2017 01:30
    Quote
    Reply # 4604854 on 4497913
    Anonymous member

    I have now found the picture of the Buzzards Bay 14 sailplan. Interestingly this shows the CLR and CE of the original sail plan. The lead is just under 7% (not taking the rudder into account)! Apparently the boat was beautifully balance with the original rig, so it it tempting to stick with Francis Herreshoff's thumb suck. Any thoughts on why this boat should have such a small lead. 

    original Herreshoff sail plan
  • 12 Feb 2017 00:28
    Quote
    Reply # 4604804 on 4497913
    Anonymous member

    Hello David, 

    Nice to hear from you and thanks very much for your valuable input. I like the idea of aero junk. Pete is scratching his head, remeasuring plans, boat etc and we don't know what is next ... Watch this space! 

    Hope your aero junk is coming together. Look forward to seeing us both on the water for AGM. 

    Linda
  • 10 Feb 2017 10:36
    Quote
    Reply # 4602287 on 4497913
    Anonymous member

    Hi All,

    looking at the design of Francis and the photos of the hull I tend to agree with Arne that the lead should be in the order of 16 to 17 percent. I found with Arcadian that 12% lead created a lot of weather helm and she did not balance until I had added to the keel aft to bring the lead back to that of the original Bermudan rig which was 17%. If the existing mast step and deck reinforcement are used then with the rigs proposed so far she will, in my opinion, have excessive weather helm. I would like to suggest an Aero junk rig similar to Pete's on Oryx. This would have approximately 25% of the sail forward of the mast, would have somewhat longer battens and would require a shorter mast rigged close to vertical. This would reduce the amount of work required and would provide a very efficient rig for the boat.

    All the best with your new boat Linda.
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