Fr J Hackett
Well-known member
Doubt it!
Me too.
Doubt it!
Compared to Ship Happens your nearly finished??Covid, family deaths(plural) , Brexit, world gone mad… there’s been a slight delay.
We’re thinking a shade of Blue for the hull. Sails and power train are getting dressed for the party.
“O ye of little faith”
Are the windows in yet? ??
Right, there's a lot of unknowns in that lot.
I guess that it's fractional - because it's got swept back spreaders. I don't think you've got your chainplates in yet, so they'll need to be fabricated to suit their new position.
You almost certainly want to keep it double spreader because the tube size will be lighter for a given length thanks to the better support. (Single spreader would have meatier tube, in theory at least).
You'll want to move the mast forward from its designed step to compensate for the changed combined centre of effort..
True, swept back spreaders are in contact with the sail more frequently, but it's really not that big a problem, and will be alleviated by your patches. If you were to change the spreader roots for inline then you'll really want to change it back to masthead rig because you'll lose the backstay effect of the sweep back and need to achieve forestay tension with just the backstay - and that wouldn't be good with the lower forestay fitting. You could fit runners of course. Personally, I'd keep it fractional - it looks better.
Rig height - well looking at pictures I think the standard rig looks surprisingly well-proportioned, and if I were ordering up a new mast would probably stick with it. On the other hand, the racer and Med sailor in me says to go for the extra couple of metres - especially since it's you that'll be paying for the extra wire, rope and sailcloth...
Boom length, well that could be longer too, but you're limited by the mizzen, so only longer by the distance forward you move the mast.
I've probably missed something, but that gives you stuff to think about.
The sleeving is invariably at the bottom, and happens because the 'standard' extrusion length is (or certainly used to be) 40 feet. Any taller and you need two bits joined. The internal sleeve then makes that section way stronger, and as it turns out is ideally suited to the gooseneck area to take the extra stress and mast winches etc..I would be leery of the splice in the mast. A weekness which will appear I think near the unsupported part of the mast. I would not be afraid of under canvassed. Less is often good especially when wind comes up. You can compensate with extra code 0 jib on bow sprit or similar if you decide you need it.
As said I would stick with 2 spreader arrangement for better support of the mast. Aft swept spreaders can mean you don't need running back stays and can do without inner forestay making tacking much easier and kinder on jib. I would not go to a lot of trouble to move mast base forward. (in moving from a mast head to fractional design. But you do need to get chain plates robust and aft of abeam the mast. Where original design might have had chain plates abeam. ol'will
I would be leery of the splice in the mast. A weekness which will appear I think near the unsupported part of the mast. I would not be afraid of under canvassed. Less is often good especially when wind comes up. You can compensate with extra code 0 jib on bow sprit or similar if you decide you need it.
As said I would stick with 2 spreader arrangement for better support of the mast. Aft swept spreaders can mean you don't need running back stays and can do without inner forestay making tacking much easier and kinder on jib. I would not go to a lot of trouble to move mast base forward. (in moving from a mast head to fractional design. But you do need to get chain plates robust and aft of abeam the mast. Where original design might have had chain plates abeam. ol'will
The sleeving is invariably at the bottom, and happens because the 'standard' extrusion length is (or certainly used to be) 40 feet. Any taller and you need two bits joined. The internal sleeve then makes that section way stronger, and as it turns out is ideally suited to the gooseneck area to take the extra stress and mast winches etc..
re righting moment. if you picture the boat laid down to horizontal your additional mast height weight plus stay wires and sail will have the same leverage as 10 times the weight on the keel. Does it matter. It all depends on if you are going to have the boat laid down to horizontal. or more importantly if you worry about that. if you ahve the patience to plow through Racing Rules of Sailing you will find formular for stability that are considered a standard for ocean racing. takes in to account ballast weights mast heights etc. You could do well to compare your proposed mast height to that formular fro comparison. ol'willI’m fabricating the chainplates well above spec. I almost had a seizure when I saw the 2mm plate ones installed.
I am leaning toward the double spreader as I like the idea of a better mast support. I’ve recently seen mast do a “dance” that I did not like to see my mast doing.
I must admit I’m very tempted to have on more metre on the mast. Just unsure how it would affect the righting moment on the boat..