H28 sloop spreaders and jumpers

[riveter]

So, my mast is off, I am now building the new one. Today I looked throught Herreshoffs original plans that came with the boat, and I am questioning my plan regarding spreaders and jumpers. I need to build new ones of each.... In Herreshoff's diagrams, he refers to the materials to use as "hard mahagony or spruce", ash or oak, as options for materials.. What do you think he meant by "hard" I was planning to fabricate these from my left over spruce from the mast..but now I have second thoughts. Feedback please..I am fabricating these tomarrow..I have honduras magagony , red oak, and of course the mast spruce in the shop.....I'm thinking just go with the spruce....???
Riveter

[Jay Greer]

White oak or ash is the traditional choice for spreaders. Mahogony would work as well but is not as strong for loading strains. Other woods do not provide the loading strength required. Spruce will work but be carful to maintain the cross sections specified by Herreshoff.

Are you building the 4'taller sloop mast for your boat that L. Francis designed in leiu of the ketch mast? In my opinion, the taller mast would be a better choice for the ketch rig in areas of prevailing light winds. The greater luff length of the headsail will afford more drive to weather as well.
One would just have to reef sooner and a double set of reef points would be a good choice.
Jay

[JamesCaird]

Hi Guys-I built all the spars and hardware for my Rozinante years ago. Used the plans to the letter and even Muriel (Yes, that Muriel) showed me the quick and easy method of transferring drawing dimensions for the hardware to the materials. Used spruce stock for the spreaders and jumpers-That rig is essentially the same as H-28 although with maybe heavier sections (?). All still going strong and that was 30 (yikes!) years ago. Cheers/JC

[riveter]

Jay,
yes, I am doing the longer sloop version, 34.6" above top deck. The ketch being 30.6". This morning I've scraped the paint off the old spreaders & jumpers. They are spruce and have been on the boat for 50 years, so I'll stick with my plan of using spruce ,as JC confirms his to be spruce with good success.
Riveter

[rbgarr]

My guess is that a 'hard' mahogany would be African mahogany. Phillippine mahogany is closer to a cedar and softer AFAIK. I don't know where Honduras mahogany falls in the scale, and have often wondered whether the mahoganies are accurately identified by sellers anyway.

I'd use spruce or ash or white oak as long as I could keep them rot-free.

[Jay Greer]

Jay,
yes, I am doing the longer sloop version, 34.6" above top deck. The ketch being 30.6". This morning I've scraped the paint off the old spreaders & jumpers. They are spruce and have been on the boat for 50 years, so I'll stick with my plan of using spruce ,as JC confirms his to be spruce with good success.
Riveter
My own aversion to using mahogony is that it is slightly brittle compared to other suitable woods. Spruce is light and is very strong for its weight under compression. However it can be fragile if subjected to side loading during stepping procedures.
When used for spreaderst it also has little resistance to abrasion from halyards dragging over it .
I will be very interested in hearing how your boat performs with the new rig.
Jay

[riveter]

If the schedule goes to plan, the mast will be ready for stepping in 2 weeks, then out for a 2 week sail and shake down before my holiday is over.
While over at my freinds shop, where the new mast is being constucted, it was suggested that I shape the spreaders and jumpers, so that they don't look so "boring" (my freinds words). He suggested I shape the leading and aft edges slightly, like an aircraft wing. I agreed, I think this would look nice....so I am working out those lines tonight.

[Jay Greer]

If the schedule goes to plan, the mast will be ready for stepping in 2 weeks, then out for a 2 week sail and shake down before my holiday is over.
While over at my freinds shop, where the new mast is being constucted, it was suggested that I shape the spreaders and jumpers, so that they don't look so "boring" (my freinds words). He suggested I shape the leading and aft edges slightly, like an aircraft wing. I agreed, I think this would look nice....so I am working out those lines tonight.
While some builders advocate an airfoil shape to spreaders, wind tunnel testing has proven that the shape chosen by Herreshoff is correct and aerodynamic. Remember that it is the underside of a spreader that adds to heeling moments on the weather side of a mast. An air foil shaped spreader, unless rotated to a three to five degree down angle around its linear axis will stall and create a greater heeling moment. Leave the design alone. Herreshoff knew what he was doing!
Jay

[riveter]

Hey Jay....thanks...I've decided to stay with the original design as you suggested...not as pretty, but proven pratical..you are bang on.....btw, your input saved me fussing over shaping the foil angles!
Anyway, the spreaders are way up there...I'm the only one who's gonna see it.
kiss...keep it simple stupid
love this forum so far..great advise
Riveter

[Jay Greer]

Riveter,
I congratulate you for making a sound choice. When seen in conjunction with the box section masts I kind of like the way they look.
Jay
http://im1.shutterfly.com/media/47b9da00b3127ccec6be3ea0820d00000040O00QYsmrNy5bsQ e3nwg/cC/f%3D0/ps%3D50/r%3D0/rx%3D550/ry%3D400/
http://im1.shutterfly.com/media/47b9da00b3127ccec6bf882da29700000040O00QYsmrNy5bsQ e3nwg/cC/f%3D0/ps%3D50/r%3D0/rx%3D550/ry%3D400/