Wharram Builders and Friends

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Have an opportunity to purchase 35ft aluminum mast for a Tangaroa I'm going to refit. It is cheap so very tempting. Did a search here at WBF and saw the advice for 34 ft on a cutter rig. Still 35ft seems a bit short. That might give me 30ft on the luff, leaning towards full batten main. Would just like to hear some opinions so I can feel a bit more confident with a 35ft mast. This is my first post of probably thousands to come. 

Herb

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Mast = LOA approx is common on single mast wharrams.

  My own mast is 30ft on P31. This works fine for me. This for masthead cutter rig. I do need a 110% genny for light air. Remember I live in a heavy wind area. For a light wind area you might think bigger?

  The approx proportions mast = Loa = 2x beam gives a very safe boat well suited to voyaging, and for me is at the "heart" of "Wharram  Philosophy" - every bit as much as deep "V" hulls.  

 A taller rig will give you a better windward and /or light air performance and will suit a lower wind area. It will also give you an exciting daysailer at the expense of voyaging/heavy weather capability.

Remember an increase of 10% in rig height leads to a loss of 21% in stability due to the "squared" effect. In practice Wharrams are so stable that they can handle this but it is not the choice for me.

 Be honest and realistic and decide what you are really going to use the boat for and where.

Many early Wharrams were narrow and I would not increase the rig on these without also widening them to Loa = 2x beam.

Boatsmith has used mast = 120% Loa approx. on the Ariki. Boatsmith and James do not agree on everything and I suspect this is one of them. I think they are both right - they just see the boat being used for different purposes. This is of course guesswork from me.

 

really appreciate your input.
I stopped by today and bought the 35 footer. I'm fairly certain it'll be a good fit.

Herb - How is progress ? One late thought I had based on my own experience of the cutter rig - If you are designing your own rig keep the inner forestay well back. In light /moderate airs I use the genoa a lot and it suffers from abrasion on the stitching from dragging across the inner forestay when tacking. The closer this is to the main forestay the worse the wear 'n tear. My cutter rig really pays in heavy winds but once the genoa is set there is little/no point setting the staysail as it is in the "shadow" of the genny. So for what it is worth I would keep the inner well back from the outer forestay and if area was an issue I would let the staysail overlap the mast. I have in fact seen reports showing that an overlapping staysail is desirable.

Safe Seas.

Progress is slow, but that is ok till now. I want to be underway by the 1st week of August. So need to step it up, literally. The mast I purchased should eventually work out. I found out there is a special Zspar fitting that goes through the mast 5 ft below the top. I need that fitting, described in their pre 2000 catalog as coquille/backing shell. Having trouble getting USspar (Zspar's US partner), to answer the phone or email. Maybe I should check in Canada for a Zspar associate. On the cruisers forum a fellow identified the hole and said it was for the cap shroud. Its the oval on the side in the picture. Today I was able to start the Honda 15 hp for the first time. Lots of little jobs to keep me busy sanding, filling holes, and cleaning. 

Always have plan B. There is a canal up in Canada, (Happy Birthday, Oh Canada!), I could take, no mast allowed.

Thanks for your input on the forestay.

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